EUROPEAN COMMISSION
DG MOVE
SEVENTH FRAMEWORK PROGRAMME
GC.SST.2012.2-3 GA No. 321592
LNG Trucks Euro V technical solutions
LNG Blue Corridors Project is supported by the European Commission under the Seventh Framework Programme (FP7). The sole responsibility for the content of this document lies with the authors. It does not necessarily reflect the opinion of the European Union. Neither the FP7 nor the European Commission is responsible for any use that may be made of the information contained therein.
Deliverable No. LNG-BC D2.1 Deliverable Title Euro V final technical solutions Dissemination level Public Written By José Luis Pérez Souto (IVECO) Massimo Ferrera (CRF) Nadège Leclerq (Westport) Mark Matchett (Hardstaff) Ingemar Magnusson (Volvo) Checked by Javier Lebrato (NGVAe) Approved by Xavier Ribas (IDIADA) Issue date 14/03/2014 LNG BC D2.1 Euro V final technical solutions Public
Revision History
Author Organization Description Jose Luis Pérez Souto IVECO Draft
Massimo Ferrera CRF Draft
Nadège Leclerq Westport Draft
Mark Matchett Hardstaff Draft
Ingemar Magnusson Volvo Draft Javier Lebrato NGVA Check Xavier Ribas IDIADA Suggested additional content and Approved Judith Dominguez IDIADA Format
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Contents 1 Introduction ...... 5 1.1 LNG Blue Corridors project ...... 5 2 Engine technologies achieved until Euro V. Exhaust after-treatment systems ...... 6 2.1 Introduction ...... 6 2.1.1 Types of Natural Gas vehicles ...... 7 2.1.2 Focus on UE Market ...... 7 2.1.3 Methane Engine Technologies available on the market ...... 8 2.2 OEM Dedicated spark ignited natural gas engines ...... 10 2.2.1 Otto cycle stoichiometric combustion ...... 10 2.2.2 Otto cycle lean burn ...... 11 2.2.3 Engines available in the current market ...... 12 2.3 OEM Dual-fuel indirect injection ...... 19 2.3.1 The dual-fuel technology ...... 19 2.3.2 Engines available in the current market ...... 20 2.4 OEM Dual-fuel direct injection High-Pressure Direct Injection – HPDI ...... 22 2.4.1 The HPDI technology ...... 22 2.4.2 Westport HPDI technology ...... 23 2.5 Homologated conversions of diesel engines ...... 27 2.5.1 Hardstaff Dual-fuel Solution and barriers ...... 27 2.5.2 Other conversions ...... 32 3 LNG fuel systems ...... 35 3.1 Systems using saturated LNG tanks ...... 35 3.1.1 Components of a Vehicle Tank ...... 35 3.1.2 Filling the LNG Tank ...... 39 3.1.3 LNG's Path from the Tank to the Engine ...... 40 3.1.4 Pressure Equalization ...... 40 3.2 Systems using cryogenic pumps in the tanks ...... 41 3.2.1 Westport iCE PACK™ LNG Tank System ...... 43 4 LNG Euro V vehicles ...... 46 4.1 OEM Iveco Stralis LNG ...... 46
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4.2 OEM Volvo FM Methandiesel...... 51 4.2.1 Features ...... 51 4.2.2 Tank and fuel system ...... 52 4.3 Hardstaff Dual-fuel solution ...... 53 4.4 Other LNG vehicles ...... 54 4.4.1 Scania P310 LNG ...... 54 4.4.2 Mercedes Econic LNG ...... 54 4.4.3 Solbus LNG buses...... 55 4.4.4 Outside of Europe ...... 57 5 Conclusions ...... 58 5.1 LNG: analysis for use in HD vehicles ...... 58 5.1.1 Advantages: ...... 58 5.1.2 Disadvantages: ...... 58 5.1.3 Compatibilities: ...... 59 List of figures ...... 61
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1 Introduction 1.1 LNG Blue Corridors project The LNG Blue Corridors project’s aim is to establish LNG as a real alternative for medium- and long- distance transport—first as a complementary fuel and later as an adequate substitute for diesel. Up to now the common use of gas as fuel has been for heavy vehicles running on natural gas (NG) only for municipal use, such as urban buses and garbage collection trucks. In both types of application, engine performance and autonomy are good with present technologies, as they are well adapted to this alternative cleaner fuel.
However, analyzing the consumption data, the equivalence in autonomy of 1 liter of diesel oil is 5 liters of CNG (Compressed Natural Gas), compressed to 200 bar. Five times more volume of fuel prevents the use of CNG in heavy road transport, because its volume and weight would be too great for a long- distance truck. This opens the way for LNG (Liquefied Natural Gas), which is the way natural gas is transported by ship to any point of the globe. NG liquefies at 162º C below zero, and the cost in energy is only 5% of the original gas. This state of NG gives LNG the advantage of very high energy content. Only 1,8 liters of LNG are needed to meet the equivalent autonomy of using 1 liter of diesel oil. A 40-ton road tractor in Europe needs a tank of 400 to 500 liters for a 1.000 km trip; its equivalent volume with liquid gas would be 700 to 900 liters of LNG, a tank dimension that could easily be fitted to the side of the truck chassis. LNG therefore opens the way to the use of NG for medium- and long- distance road transport.
LNG has huge potential for contributing to achieving Europe’s policy objectives, such as the Commission’s targets for greenhouse gas reduction, air quality targets, while at the same time reducing dependency on crude oil and guaranteeing supply security. Natural gas heavy-duty vehicles already comply with Euro V emission standards and have enormous potential to reach future Euro VI emission standards, some without complex exhaust gas after-treatment technologies, which have increased procurement and maintenance costs.
To meet the objectives, a series of LNG refueling points have been defined along the four corridors covering the Atlantic area (green line), the Mediterranean region (red line) and connecting Europe’s South with the North (blue line) and its West and East (yellow line) accordingly. In order to implement a sustainable transport network for Europe, the project has set the goal to build approximately 14 new LNG stations, both permanent and mobile, on critical locations along the Blue Corridors whilst building up a fleet of approximately 100 Heavy-Duty Vehicles powered by LNG.
This European project is financed by the Seventh Framework Programme Figure 1-1. Impression of the LNG Blue Corridors (FP7), with the amount of 7.96 M€ (total investments amounting to 14.33 M€), involving 27 partners from 11 countries.
This document corresponds to the 1st deliverable within work package 2. It is a description document about the technology used until Euro V stage This document will be available at the project website: http://www.lngbluecorridors.eu/ .
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2 Engine technologies achieved until Euro V. Exhaust after-treatment systems 2.1 Introduction Internal Combustion Engines (ICE) have been on the marketplace for a long time and they will continue to be in place for several decades. The demand to reduce air pollution due to transportation vehicles involves the adoption of alternative fuels able to decrease progressively the dependence on crude oil.
The drives towards the adoption of alternative fuels come down to six key issues:
• energy security: the fuel has to allow usage of imported crude oil to be reduced and to have alternative and better geopolitically distributed sources than crude oil with a suitable ratio in terms of consumption / reserves
• environmental benefits: lower gaseous (i.e. CO 2, NOx, particulate matter, ozone promoters, greenhouse gases) and lower acoustical emissions • safety: the fuel has to guarantee the same or a better safety standard than gasoline / diesel oil • performance: the fuel has to comply with customer appeal comparable to conventional fuels in term of availability (adequate number of refilling stations per area), vehicle range and vehicle/engine performance, including reliability and durability as available for diesel units • economics: the fuel has to be cheaper than gasoline / diesel oil to recover the additional vehicle cost within a reasonable period of time • serviceability of the equipment, a framework for certification of pressure vessels used onboard vehicles, and the availability of trained technicians
One of the strategic options to fulfil the above-mentioned drives is natural gas because it is:
• a viable near/medium term option for energy diversification and to lessen the transportation system’s dependence on crude oil due to globally wider reserves and a better geopolitical distribution
• an intrinsically clean fuel with the lowest carbon content and tailpipe CO 2 emissions among
hydrocarbon fuels, able to heavily reduce transportation greenhouse gas emissions (CO 2), and to provide significant contribution to air quality improvement through reduction in particulate matter and NOx • a structurally cheaper solution due to less expensive production, transportation, and distribution and the technology is proven, available, and at low cost compared to other alternatives to diesel • a strategic asset that supports progressive diversification from fossil fuels as bio-methane or hydrogen produced from renewable sources and biomasses
The increased costs of fuel and the increasing attention to pollutant emissions push industrial research to find new strategies regarding the use of alternative fuels for any kind of vehicle.
Worldwide, by 2010 there were 12.7 million natural gas vehicles, led by Pakistan with 2.7 million, Iran (1.95 million), Argentina (1.9 million), Brazil (1.7 million), and India (1.1 million). The Asia-Pacific region leads the world with 6.8 million NGVs, followed by Latin America with 4.2 million vehicles. In the Latin
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American region almost 90% of NGVs have bi-fuel engines, allowing these vehicles to run on either gasoline or CNG. In Pakistan, almost every vehicle converted to (or manufactured for) alternative fuel use typically retains the capability to run on ordinary gasoline (or diesel).
In Western Europe, Italy is the largest European market.
Figure 2-1 (Source NGVA Europe) 2.1.1 Types of Natural Gas vehicles NG vehicles can be divided into the following three categories:
• Mono fuel: dedicated natural gas vehicles designed to run on natural gas/bio-methane only; • Bi-fuel vehicles: running on natural gas/bio-methane or gasoline: since natural gas is stored in high-pressure fuel tanks, bi-fuel vehicles require two separate fuelling systems; • Dual-fuel vehicles: running on bio-methane/natural gas but using diesel for ignition assist. They allow users to take advantage of the efficiency of the diesel engine but without the risks associated with running out of gas because of the existing wide-spread availability of diesel as a fall back. When bio-methane/natural gas is available, the dual-fuel vehicle can use a cleaner, more economical alternative. Dual-fuel technologies come in a number of formats, some have a full diesel only running mode, others have a limp-home diesel mode.
Light-duty vehicles typically operate in mono-fuel or bi-fuel modes, whereas heavy-duty vehicles operate in mono-fuel or dual-fuel modes. Conventionally, vehicles in which an auxiliary tank for a different fuel is incorporated, but where this fuel has a capacity not exceeding 15 litres, are also considered to be mono-fuel.
2.1.2 Focus on UE Market According to Directive 2007/46/EC concerning type approval of vehicles, all petrol/gas vehicles having a petrol tank not exceeding 15 litres should be classified as “mono-fuel” and beyond this value the classification will be “bi-fuel”. However, Regulation (EC) No 443/2009 of the European Parliament and of the Council says that "in the case of bi-fuelled vehicles (petrol/gas) the certificates of conformity of which bear specific CO 2 emission figures for both types of fuel, Member States shall use only the figure measured for gas". Also Commission Regulation (EU) No 1014/2010 of 10 November 2010 on "monitoring and reporting of data on the registration of new passenger cars" pursuant to Regulation (EC) No 443/2009 obliges Member States to treat mono-fuel and bi-fuel vehicles as natural gas vehicles (also important for fiscal treatment of these vehicles). 'Flex-fuel' means that up to three different types of fuel can be used.
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The picture below shows available OEM models on UE market for trucks.
Figure 2-2 NGV available on the market – Trucks (Source NGVA Europe) There are also a number of retrofit systems on the market. Those systems can be fitted on diesel trucks to enable their operation in dual-fuel; however they are not officially approved by the vehicle manufacturers.
Retrofitted dual-fuel vehicles are certified upon a vehicle-to-vehicle individual approval, following national regulations, and are not accepted in all EU Member States.
Those vehicles are considered as exceptions, as there is still no regulation in place which allows a complete EU approval of retrofit kits for dual-fuel trucks. The document focuses mainly on the OEM solutions and not the retrofit kits.
Figure 2-3 Dual fuel retrofitted trucks avalaible through official dealer network 2.1.3 Methane Engine Technologies available on the market Nowadays there are two types of engine on the market available for using natural gas: spark ignition engines and compression-ignition dual-fuel engines.
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To adopt a certain approach it is mandatory to take into account the following features of natural gas as fuel:
• Methane has higher octane number (knock resistance) • Methane has higher ignition temperature (650°C compared to gasoline at 350°C and diesel 250°C) • Methane has lower cetane number (needs aid for ignition) • Methane is a gas and therefore occupies more space inside the engine cylinders than liquid fuels (10-20% loss of performance) • Cooling from fuel enrichment not possible (leading to high combustion and exhaust temperatures) • Burning is without soot (low particulate matter emissions but also increased wear on valves and valve seats from lack of lubrication)
An engine designed to run on 100% natural gas requires spark ignition, and is therefore generally used in either dedicated natural gas vehicles or in vehicles that are designed to run on either natural gas or gasoline (bi-fuel vehicles). Bi-fuel vehicles with a CNG and gasoline fuel tank have the advantage of an enhanced driving range, together with flexibility if CNG refuelling infrastructure is not available. For commercial vehicles (mainly devoted for fleet) usually the spark-ignited engine runs just in natural gas mode without need of gasoline emergency mode due to well-known mission and central station availability. In this way it is possible to maximise the exploitation of natural gas as fuel in terms of engine efficiency. Diesel engines tend to be more efficient than gasoline engines, as they utilise a compression-ignition cycle rather than an Otto cycle. Dual-fuel natural gas vehicles are able to utilise the compression-ignition cycle, by using an amount of diesel as a ‘pilot fuel’ to initiate combustion (using the heat generated by compression), but replacing the rest of the diesel with natural gas. The level of natural gas used in dual-fuel engines varies depending on the engine load and knocking issues due to high compression ratio.
For heavy-duty application several technologies have been considered by OEM manufacturers such as:
1. Otto cycle stoichiometric combustion 2. Otto cycle lean burn 3. Diesel cycle with natural gas fumigation (Dual Fuel) 4. Diesel cycle with natural gas direct high pressure (300 bar) injection
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Figure 2-4 General overview of technologies used. (Source:CRF) The table above shows the types of combustion, injection, EMS (electronic management system) and after-treatment system for the different technologies used per OEM.
2.2 OEM Dedicated spark ignited natural gas engines 2.2.1 Otto cycle stoichiometric combustion Is the same concept adopted for passenger car CNG engines both in terms of subsystems and materials excluded gasoline emergency mode.
The gasoline emergency mode is considered just for delivery vans, but not 100% of duties.
This concept adopts an ignition system like spark-ignited engines, multipoint or single-point port fuel injection and a 3-way catalyst as after-treatment for exhaust gases and needs a dedicated electronic control unit (ECU) to manage all the engine functions.
The engine runs in stoichiometric ratio in all operating conditions and therefore performs the best solution for emission control. With modern distribution devices and combustion chamber it is possible to comply with level of performance equivalent to diesel engine and simultaneously reducing fuel efficiency gap to 10-15% respect to diesel engine as reference. In terms of CO 2 emissions, this kind of combustion shows levels 5-10% lower than diesel.
The technology useful for this combustion concept is simple, mature and cheap.
For some engines, a residual drawback of this approach could be high thermal load that limits full performance. This issue can be overcome by the adoption of an EGR (Exhaust Gas Recirculation) system delivered at high rate during full load operations diluting air charge and therefore reducing thermal load.
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The 3-way catalyst above a certain exhaust gas temperature at inlet (light off) is able to simultaneously convert HC, NOx and CO into CO 2 and H2O with efficiency higher than 95%.
The light off temperature for NOx and CO is close to 250 °C and for THC (mainly CH 4) is close to 450 °C. Adopting a proper location of the catalyst even at idle (worst case) the exhaust gas temperatures enable full device efficiency.
E M S
Figure 2-5 Otto Cycle Stoichiometric combustion (Source CRF) 2.2.2 Otto cycle lean burn Is based on spark-ignited engines but instead of stoichiometric operation, lean-burn combustion occurs. In principle lean-burn combustion provides better fuel economy figures than stoichiometric, but not at the same level of diesel combustion cycle with relevant impact on after-treatment especially to contain hydrocarbons as a consequence of approaching misfire lean zone and nitrogen oxides similarly to diesel engine. The trade off-between performance / fuel economy / emissions is a complex and expensive after-treatment system with just the discount of particulate filter trap and a de-rating of combustion to comply with emissions that cannot maximise the exploitation in terms of fuel economy.
Performance is not an issue for steady-state modes but less transient response is expected in comparison to stoichiometric due too large amount of air to manage during these events.
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EMS
DOC+SCR
Figure 2-6 Otto Cycle lean burn (Source CRF)
Figure 2-7 Explanation of Rich & Lean – Burn combustion 2.2.3 Engines available in the current market 2.2.3.1 Iveco Cursor 8 Natural Gas engine
Since 1994 Iveco has been able to offer a range of natural gas vehicles and is today the leader in Europe in research and production of natural gas engines and vehicles, with thousands of vehicles at work in both private and public administrations.
All Iveco natural gas vehicles use a dedicated natural gas spark ignition engine operating under a stoichiometric combustion strategy. This allows the engines to operate with consistently high performance, reducing pollution emissions well within the limits defined by the Environmentally Enhanced vehicle specifications.
The gases used for the engine certification tests, the very arduous ETC (European Transient Cycle), are designed to reflect the extreme natural gas composition found in use throughout Europe, including LNG and purified bio-methane.
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• The GR gas: 87% methane, 13% Ethane • The G25 gas: 86% methane, 14% Nitrogen
The Cursor 8 GNC engines are produced by FPT - Fiat Power Train - , as Iveco, a company integrated in CNH Industrial.
This engine was initially developed to cover the mature market of the buses and garbage trucks running on CNG. At the end of the decade of 2000, other market segments were interested in purchasing natural gas vehicles (as well as LNG): namely, distribution companies. In order to satisfy this request an upgraded version of this engine was developed with 330 hp and 1.300 Nm of torque. This version of the Cursor 8 is the heavy-duty dedicated gas engine with the highest specific engine output (power / displacement ratio) on the market.
Figure 2-8 Iveco – FPT Cursor 8 GNC engine (Source Iveco) Cursor 8 CNG engine specifications are shown below.
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Figure 2-9 (Source FPT)
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2.2.3.2 The Cummins-Westport ISL G engine
The Cummins Euro V natural gas heavy-duty truck engine is the ISL G model1.
The ISL G engine is the leading natural gas truck engine in North America (EPA 2010 certification) and one of the most common ones globally. Cummins Westport Inc. announced in July 2011 the production and celebration of the 10,000th ISL G natural gas engine. Cummins Westport ISL G engines are sold globally in a variety of applications including shuttle and school buses, urban transit, vocational, and medium and heavy-duty truck and tractor applications. The ISL G is available as a factory option from leading bus and truck manufacturers and its ability to operate on CNG, LNG or bio-methane has made it the leading natural gas engine in North America.
Figure 2-10 ISL G Engine – (Source Westport) The ISL G engine block is shared with the Cummins ISL diesel. The ISL G engine is an 8.9 litre, 247 – 316 hp factory-built, dedicated natural gas engine that uses advanced stoichiometric combustion with cooled EGR to meet ultra-low emissions requirements. The cooled-EGR system takes a measured quantity of exhaust gas and passes it through a cooler to reduce temperatures before mixing it with fuel and the incoming air charge to the cylinder. This lowers combustion temperatures and knock tendency, reducing engine out emissions and noise.
Three Way Catalyst
EGR Cooler
Charge Air Air Cooler Charge Fuel
Throttle
Figure 2-11 Cummins Westport Spark Ignited Stoichiometric Technology with cooled EGR – (Source Westport)
1 Source: http://cumminsengines.com/showcase- item.aspx?id=95&title=ISL+G+for+Euro+Truck+%26+Bus&Filters=3%3AEuro+5&Categories=192%2C 38#overview
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Figure 2-12 ISL G Euro V Ratings and Specificatons (Source Cummins Westport) Additional ISL G engine features:
• Air/Fuel Regulation – Cummins closed-loop electronic control system based on Cummins Interact™ System. Sensors for engine parameters, including intake manifold pressure and temperature, fuel inlet pressure, knock detection, air/fuel ratio and fuel mass flow. • Closed crankcase ventilation (CCV) – new remote mounted system required to re-cycle blow- by gases now counted in the engine emissions. • Cummins Wastegated Turbocharger – developed by Cummins Turbo Technologies with electronic control for precise air handling. Has a water-cooled bearing housing for durability. • Air Intake System – charge air cooling reduces emissions by lowering intake manifold air temperatures. • Maintenance-Free After-treatment – uses a Three-Way Catalyst (3WC) after-treatment. 3WCs are effective, simple, passive devices, packaged as part of the muffler, that provide consistent emissions control performance and are maintenance-free. The ISL G does not require active after-treatment such as a Diesel Particulate Filter (DPF) or Selective Catalytic Reduction (SCR). • High-Energy Ignition System – spark-ignited system providing better performance and longer service intervals with improved spark-plug and coil durability. • High-Efficiency Lube Cooler – lowers oil temperatures for longer engine life. • Accessory Belt Drive System – self-tensioning serpentine poly-vee belt accessory drive system for water pump, engine-mounted fan hub and most alternators. Gear-driven air compressor with provision for gear-driven hydraulic pump.
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• Crankshaft – eight counterweight, fully balanced, hightensile- strength steel forging with induction hardened fillets and journals, for outstanding durability. • Control System – full drive-by-wire. Electronic Control Module (ECM) provides full monitoring and control of the engine sensors, fuel system and ignition system. Full interface capability to Cummins INSITE and diagnostic service tools. • Oil Filter – the combination full-flow and bypass oil filter improves filtration while minimizing oil filter replacement and disposal costs.
Even though the ISL G engine is capable of operating on CNG and LNG, in Europe it is primarily used in CNG vehicles. European truck and bus OEMs offering the ISL G Euro V engine include Renault Trucks / PVI, Solbus, Solaris, TEMSA and others. Solbus uses natural gas buses running on LNG using the ISL G engine. The ISL G engine is very common for LNG trucks in North America.
Cummins also announced that the ISL G moves to Euro VI emissions with minimal changes from Euro V.
2.2.3.3 Scania NG dedicated engine
Euro 5/EEV
• 270 hp at 1,900 r/min and 1,100 Nm between 1,000 and 1,400 r/min • 305 hp at 1,900 r/min and 1,250 Nm between 1,000 and 1,400 r/min
Principle: Spark plugs, lean-burn Otto combustion, waste-gate turbocharger, single-point fuel injection and lambda sensor, oxidising catalyst
Fuel: Compressed or liquefied natural gas or biogas
Figure 2-13 OC9 Euro V/EEV Ratings (Source Scania) Euro 6
• 280 hp at 1,900 r/min and 1,350 Nm between 1,000 and 1,400 r/min
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• 340 hp at 1,900 r/min and 1,600 Nm between 1,100 and 1,400 r/min Principle: Spark plugs, stoichiometric Otto combustion, waste-gate turbocharger, 5-20% cooled EGR, multi-point port fuel injection and three-way catalyst
Figure 2-14 OC9 Euro VI/EEV Ratings (Source Scania) 2.2.3.4 Mercedes NG dedicated engine
The supercharged in-line six-cylinder M 906 LAG engine has a displacement of 6.9 l and impresses with its 205 kW (279 hp) output and has a maximum torque of 1.000 Nm
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Figure 2-15 OM906 Natural Gas Euro V/EEV Ratings (Source Mercedes Benz) 2.3 OEM Dual-fuel indirect injection 2.3.1 The dual-fuel technology Dual-Fuel approach (also called fumigation) means adopting diesel cycle combustion using diesel pilot injection like a liquid spark plug then the single combustion stroke continues by means of natural gas delivered into inlet duct of each cylinder.
Full diesel operations are requested at idle due to combustion stability issues and at full load diesel quantities might be increased to avoid knocking depending on the fuel. As matter of fact the compression ratio is maintained equivalent to diesel version and the introduction of natural gas before piston top dead centre position can lead too high cylinder pressure if combustion is not monitored accurately. Dual-Fuel engine provides better fuel economy figures than stoichiometric spark-ignited engines at the same level as diesel engines cycle except at light-load conditions where the engine will run on diesel only.
In terms of energy, a realistic average diesel substitution fraction by natural is 50% with peak of 60- 80% at medium high load conditions.
Managing the exhaust emissions requires similar exhaust after-treatment as the diesel engine and an additional dedicated methane catalyst is needed to meet EUV emissions. The technology is relatively simple allowing diesel engine retrofit solutions. For optimal performance an integrated OEM solution is needed. A major advantage with the dual-fuel technology enables pure diesel mode should gas not be available.
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Figure 2-16 Diesel cycle with natural gas fumigation (Dual Fuel) (Source CRF) 2.3.2 Engines available in the current market 2.3.2.1 2.3.2 The Volvo D13
Features
The new Volvo FM MethaneDiesel represents a giant step forward in the field of gas-driven, commercial heavy vehicles. By utilising liquefied gas in the diesel engine, it enables longer and heavier transports – a unique quality for a gas truck. In addition, this truck delivers fuel efficiency similar to the diesel truck, resulting in up to 25% lower fuel consumption compared with traditional gas vehicles. And, should gas not be available, it runs smoothly on diesel as well. The Volvo methane-diesel principle enables heavy-duty diesel engines to operate substantially on natural gas or biogas. On a regional or long-haul route, this means up to 75 % gas and 25 % diesel. With the basic diesel engine fully intact, retaining its original energy efficiency, the truck is able to run entirely on diesel at any time.
Figure 2-17 Volvo FM MethaneDiesel multipoint gas injection system
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How it works
Injection of gas into the cylinder is done by a multipoint gas injection system installed in an injector plate. Pilot amounts of diesel are injected directly in the cylinder to ignite the gas. A special dual-fuel ECU, integrated with the standard engine control unit, performs real-time control to optimise diesel substitution.
The engine starts on diesel and goes into MethaneDiesel mode when the coolant temperature reaches a sufficient temperature. The diesel is ignited by compression-ignition and in turn ignites the gas and air mixture. The combustion process is optimised by accurate control of both diesel and gaseous fuels and by a turbo air bypass valve that controls the intake air to achieve desired air/fuel ratio. To protect the engine from varying gas properties in Europe, two knock sensors are mounted on the engine block. They monitor the engine block for frequencies of vibration associated with knock. If knock is detected, the ECU will alter the diesel injection timing and air/fuel ratio to stop it from occurring. If knock persists the engine returns to diesel mode to protect the engine.
The engine will continue in MethaneDiesel mode provided that adequate air-fuel ratio conditions can be met to sustain efficient gas combustion. The engine air-flow is constantly monitored. At low torque levels, for example at idle, the presence of too much air makes the air-fuel ratio too lean to sustain combustion of gas. At such light-load conditions the engine will run on diesel only. Therefore, best gas use is achieved when the vehicle duty cycle is reasonably loaded. The engine is equipped with a dedicated methane catalyst optimised for methane oxidation, in addition to the diesel exhaust after-treatment system.
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Technical facts for Volvo FM MethaneDiesel:
D13C-Gas 460 hp
No. of cylinders 6
Displacement 12.8 dm3
Stroke 158 mm
Bore 131 mm
Compression ratio 17.8:1
Max output at 1400-1850 r/min 338 kW
Max torque at 1100-1400 r/min 2300 Nm
Economy rev range 1100-1500 r/min
Exhaust braking effect (2300 r/min) 185 kW
Effect – VEB+ (2300 r/min) 375 kW
VEB+ available as an option on all
D13C-Gas engines
Oil filters, 2 full-flow, 1 bypass
Oil change volume, incl. filters approx. 33 l
Cooling system, total volume approx. 38 l
2.4 OEM Dual-fuel direct injection High-Pressure Direct Injection – HPDI 2.4.1 The HPDI technology Direct injection of natural gas with pilot injection of diesel oil, according to diesel cycle, is able to overcome knocking issues of fumigation combustion thanks to injection of natural gas after top dead centre. In principle this concept exploits the benefits of lean-burn combustion and diesel cycle, but it requires a natural gas injection pressure between 200 and 300 bar. These pressures can be achieved just with a fuel stored in liquid form into the tank, pressurized by high-pressure liquid pump and then pressurized fuel is vaporized at high pressure.
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Therefore the technology can be adopted only for LNG applications. CNG applications are out of scope. Performance and fuel economy can be similar or equivalent to diesel engine but there is not any possibility to have a diesel emergency mode.
After-treatment requested is equivalent to diesel and dual-fuel engines: complex and expensive.
The main devices are oxidant catalyst, SCR, urea injection, Diesel particulate filter, clean up catalyst, ammonia and NOx sensors.
Figure 2-18 Diesel cycle with natural gas direct high pressure (300 bar) injection (Source Westport) The only dual-fuel direct injection technology currently available for HDVs globally is the Westport HPDI (high-pressure direct injection) technology. It is important to mention that there are no engines using this technology commercialised in Europe yet. Engines featuring this technology are commercialised in North America and Australia (certified to 2013 EPA and CARB emission standards), and have been announced for China (China V emission standards). The technology, however, is designed to meet Euro VI emission regulations
2.4.2 Westport HPDI technology Westport High Pressure Direct Injection technology retains the operating principles of the base diesel engine—direct injection near top dead centre, auto-ignition, diffusion combustion, and the thermodynamic diesel cycle—and so retains its operating characteristics.
Gas is supplied using a special high-pressure gas injection system. Pilot quantities of diesel fuel are injected into the cylinder in order to accomplish ignition. At the heart of the engine is a special injector with a dual-concentric needle design. It allows for small quantities of diesel fuel and large quantities of natural gas to be delivered at high pressure to the combustion chamber. The natural gas is injected at the end of the compression stroke. This unique HPDI injector concept enables the double injection to take place within a single injector that fits in the same location as the original diesel injector.
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Figure 2-19 Westport HPDI Injector Tip Assembly (Source Westport) HPDI replaces >90% of the diesel fuel (by energy) with natural gas.
Major advantages of HPDI engines are that they match the parent diesel engine in power, torque, efficiency, and transient response, which no other gas engine can do. They reduce greenhouse gas (GHG) emissions by about 20%. Such engines are not limited by knocking at high loads and their HC emissions are low. An HPDI engine is a diesel-cycle engine that runs on natural gas, rather than being a conversion to the Otto cycle, which most other gas engine are.
2.4.2.1 Westport 15L Engine (North America, Australia)
The Westport™ 15L engine is currently the only engine featuring Westport™ HPDI technology in the market. This engine is commercialised in North America and Australia, certified to 2013 EPA and CARB emission standards. Featuring Westport first generation HPDI systems, it has been delivered on more than 1,200 Peterbilt and Kenworth trucks since its first wide-scale introduction in 2010.
Figure 2-21 Westport 15L engine ratings (Source Westport) Figure 2-20 Westport 15L engine (Source Westport)
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Figure 2-22 Westport 15L engine speed and torque (Source Westport)
Figure 2-23 Westport 15L engine specifications (Source Westport) 2.4.2.2 Weichai Westport WP12HPDI Engine (China)
The introduction of China's first natural gas engine featuring Westport high pressure direct injection (HPDI) technology was announced in March 20122. This is a 12-litre engine (12L WP12HPDI Engine) based on the Weichai Power WP12 engine platform. The product introduction is the result of China's first joint venture for HPDI natural gas engines—Weichai Westport Inc. The Weichai Westport HPDI engine has been undergoing road testing with a select OEM customer, Shaanxi Automobile Group.
2 Source: http://www.westport.com/news/2012/chinas-first-engine-with-westport-hpdi-technology- unveiled-during-china-national-peoples-congress LNG BC D2.1 Euro V final technical solutions Public
Figure 2-24 Weichai Westport WP12HPDI Engine (Source Westport) From a technical perspective, the Weichai Westport HPDI engine delivers the same power and torque (WP12HPDI Landking engine's rated power is at 480 hp @ 2,100 rpm, with maximum torque of 1,970 N·m @ 1,200–1,500 rpm) as that of the original diesel engine, and identical performance as that of the diesel engine. The engine's power and torque is 20% and 20-25% higher than that of the spark ignition natural gas engines respectively. Hence, it solves the problem of large plateau power loss for gas engines.
2.4.2.3 Future Products
The current generation of HPDI on the Westport 15L engine is still assembled in Vancouver using an up-fit process. Westport's production focus is shifting from an up-fit model to vertical integration of Westport's next generation of HPDI for targeted OEMs. November 15, 2013 was the last day for orders for the 15L engine with Westport HPDI with 2013 Environmental Protection Agency 2010 certification. However, Westport plans to continue to offer an HPDI solution for Australia in concert with Westport's fuelling partners for the foreseeable future.
In December 2013, Westport unveiled its next generation of high-pressure direct injection technology platform dubbed "Westport™ HPDI 2.0” 3. As per the company’s news release, this new generation of the class-leading natural gas technology will provide global vehicle and engine OEMs with a vertically integrated natural gas solution with breakthrough price, performance, and fuel economy. Developed to the most rigorous OEM quality standards, Westport™ HPDI 2.0 system components will offer ready integration into OEM operations globally, and provide an attractive way to reach scalable volume deliveries as natural gas markets mature and grow.
Westport is now working with seven OEM applications with engine sizes ranging from trucks to trains at various stages of development with the goal of vertically integrated Westport™ HPDI 2.0 OEM product lines. Westport anticipates first availability of customer products in late 2014 and 2015.
3 Source: http://www.westport.com/news/2013/next-generation-high-pressure-direct-injection- system-hpdi-2.0 published December 10, 2013
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2.5 Homologated conversions of diesel engines 2.5.1 Hardstaff Dual-fuel Solution and barriers 2.5.1.1 Introduction
The Hardstaff OIGI® (Oil Ignition Gas Injection) technology, originally conceived in 1999, is an electronic system that reduces the amount of diesel injected into a cylinder of a diesel engine, equally replacing the fuel with natural gas without affecting engine power and characteristics of the original diesel engine. The technology has been developed to utilise natural gas (compressed-CNG or liquefied-LNG) and bio-methane (LBM/LBG) as the primary fuel source.
2.5.1.2 Technical Background
When developing the OIGI® system the safety implications of interfering with the Can Bus operations were recognised. The developers decided that the optimal method for reducing diesel would be to intercept the diesel injector signals. This method requires no access to the OEM ECU and since the signals are intercepted after the OEM ECU has determined the mass of diesel, its operations are unaffected, allowing functionality comparable with diesel operation.
The Hardstaff dual-fuel system intercepts the diesel injector signals and emulates the diesel injector to satisfy the OEM ECU’s expected injector return signal. This allows complete control of the quantity of fuel injected and the timing of each injection. For each injector signal received the desired mass of diesel to be injected is calculated. A complex model determines the maximum available diesel reduction. A reduced diesel injection signal is sent to the injector, and a gas injector signal is sent to provide an equivalent energy content of the diesel removed. Clearly gas injection must commence prior to diesel injection, as the gas is injected during the induction stroke. Hence the dual-fuel operation is delayed for the next available cylinder cycle.
The gas injection system functions with a sequential operation and has been developed in conjunction with UK universities to provide fully optimised strategies and mixing fields, ensuring accurate delivery of natural gas. The system comprises two gas injectors per cylinder; this enables sufficient mass and optimises the gas mixing process. Since the calculations are on a mass basis accurate gas injection is achieved with automatic compensation for gas temperature and pressure.
2.5.1.3 Operation
The technology has many built-in safety features to ensure engine operation is not affected. The unit operates as a slave to the OEM ECU. If any fault occurs (e.g. gas injector failure) the system will hibernate and revert to 100% diesel operation. Similarly if a diesel injector fault occurs the technology will hibernate.
Part of the technology solution developed is a bespoke exhaust after-treatment reducing both Non- Methane Hydrocarbons and Methane below current European emission limits. The after-treatment systems are designed to work in conjunction with Selective Catalytic Reduction systems at OBD1 and OBD2 levels and offer significant enhancement to current systems.
In order to accommodate the addition of methane catalysts in the exhaust system the Ad Blue injector location has to be re-engineered. The methane catalysts must be installed upstream of the SCR system, hence the injector is positioned after the methane catalysts. This repositioning has no effect on
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performance of the SCR system, emissions or noise. In dual fuel mode the AdBlue injection benefits from the NO to NO2 conversion resulting from the addition of the methane catalyst.
2.5.1.4 History
Hardstaff originally conceived the OIGI® technology in 1999 and has been working on the development of the system since then. Initial development work was undertaken on easily available vehicle engines through two collaborative projects with Caterpillar (1999) and Clean Air Power (2002- 2003). Early engines manufactured during the Clean Air Power project had the intrinsic problems of any embryonic technology; it was inflexible with limited power availability and it relied heavily on input from the Engine Management System (OEM). Testing was carried out at Leyland Technical centre, Millbrook and Perkins Engine Test Cells. At this time Hardstaff also developed its own exhaust technology to support the electronic engine system, which enabled VCA approval for Euro 4 ETC. The outcome of the project was the successful conversion of 128 vehicles to natural gas as the primary fuel source, many of which are still operational today in UK fleets.
Since 2003 Hardstaff has invested significant amounts of company funds into designing new innovative hardware and closed-loop software systems. The objective of the work was to produce a technology capable of enabling electronically controlled engines to run in dual-fuel mode without changing the original type approval of the engines’ electronics. Testing of the technology has been undertaken using Hardstaff’s own fleet of HDVs both within a bench test environment and through millions of kilometres of road testing.
2.5.1.5 Facilities and Methods
Engine developments have been carried out using the Hardstaff in-house test cell and emissions measurement equipment. Cylinder pressure and emission testing has also been carried out in conjunction with the Thermo fluids departments at UK universities. Hardstaff has recently commissioned additional test cell facilities to determine engine performance, fuel economy and tail pipe emissions by developing and validating mathematical models, evaluating and validating actual duty cycle results and engine out emissions
Initial research confirmed that the use of methane in a high compression engine leads to a reduction in NOx emissions, and by ensuring peak cylinder pressure is not exceeded, the wear and operation characteristics of the diesel engine are unaffected. This is achieved from an in-cylinder homogenous charged gas/air mixture providing an improved torque curve. The latest patented technology developed improves sequential gas injection and diesel displacement – maximising safe and efficient substitution. Additionally the technology controls the diesel injector signal and no longer requires access to the OEM ECU.
Previous attempts to introduce dual-fuel technology to diesel engines have been unsuccessful, affecting the fuel economy, power output, durability, and all aspects of diesel engine performance. Typical side effects are caused by the inefficient control of fuel and timing maps designed by the OEM.
The Hardstaff system is unique in that it does not require access to the manufacturers ECU in order to control diesel reduction and injection timing. This unique approach preserves the integrity of control mechanisms designed by the manufacturer, and does not affect safety, braking control, and intelligent gear box systems, etc.
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Substitution of diesel by natural gas/bio-methane can be as high as 80%; dependent on vehicle applications and limitations of the original diesel engine, and typically is between 55%-65% in a mixed operation.
2.5.1.6 Objectives
The objectives and consequences of dual-fuel operation:
• Reduced CO 2 emissions in adapted vehicles by up to 18% when compared with 100% diesel
• Reduced CO 2 emissions in excess of 30% when compared with a dedicated gas engine • Further reductions in carbon emissions through the use of bio-methane • Retention of the thermal efficiency of a diesel engine and therefore established fuel consumption, power and torque curves • Reduction in particulate and non-methane hydro carbon emissions • Reduction in and change in the NOx output, offering a reduction in amount of AdBlue used • Retention of the driving characteristics of a diesel engine • Not restricted to a typical 240 kW power output • Heat rejection lower than a dedicated gas engine • No physical changes to the diesel engine operation, thus retaining residual values • Retention of 100% diesel operation fall-back should the supply of gas not be available • Reduced dependency on crude oil
2.5.1.7 Current Developments
Although a number of vehicle brands and types have been converted on trial basis, mostly in the early days of development, more recently Hardstaff have worked almost exclusively in long distance heavy vehicles with Daimler through its Mercedes-Benz range of heavy trucks. In addition, for smaller vehicles, the Group has a conversion solution for a number of four and six cylinder engines in the 6-8 litre class, including Volvo and M-B.
In terms of heavy long distance vehicles, it can currently offer a dual-fuel solution for the Axor and Actros range of Mercedes-Benz vehicles, and has to date supplied around 400 of these vehicles, mostly in the UK, but some further afield, mostly in mainland Europe. Hardstaff operates a number of these vehicles in its own transport fleet which facilitates on-going performance analysis.
The Hardstaff Group is committed to the demonstration and development of a retrofit, or off-line production dual-fuel solution for Euro VI HCVs, it has spent considerable time and effort in developing commercially workable solutions for earlier legislation, and sees the ability to offer a future proof product as essential to its future. Hardstaff currently has a UK project running, part funded by the Technology Strategy Board, to produce a prototype dual fuel (retrofit) Euro VI HCV; this two year project has been running since December 2012. Early results have been extremely encouraging. Clearly, this early on in the project it would be foolish to predict a firm date for success i.e. a running dual-fuel Euro VI based vehicle, but it is reasonable to expect that this will be possible in the second or third quarter of 2014. From what we know of planned OEM technology we believe that this could mean that Hardstaff are able to offer the first Euro VI dual-fuel vehicle for demonstration within the Blue Corridor.
Hardstaff’s market feedback indicates that without the offer of a dual-fuel truck with full diesel running capabilities, the overall commitment of fleets will only be to small numbers of trucks. This would reduce the potential impact on their service levels to customers as a result of failure of the gas supply
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chain, which at this early stage must be considered possible. In turn severe commercial pressures would be placed upon the station providers within the project. Trucks with no diesel only mode may result in such severe service level agreements being placed upon station providers as to act as a disincentive to enter the market. These factors are the principal drivers to the direction of Hardstaff’s technology strategy, which embodies a full unrestricted diesel operating mode.
In turn development work carried out under the Blue Corridors project is seen as being not only important to the project per se, but also as a very useful route to market for the technology. Although Euro V will become obsolete in Western Europe after 2014, there are many world territories where Euro V, or its equivalent, will continue to be sold for many years in the future; these include many Eastern European countries, South America, Asia etc. Many of these countries have their own gas supply and infrastructure serving gas powered cars and light vans.
Technical Challenges and Market barriers
The large diesel engines to which dual-fuel conversions are applied are all designed and optimised to operate on 100% liquid fuel. Although tolerant to a mixture of diesel and gas, inevitably they will not operate to the same level of efficiency as an engine designed specifically for dual fuel at an OEM stage. In particular components such as pistons, manifolds and injectors, although ideal for diesel operation will result in a combustion process that is not fully optimised. This poses two particular challenges, upon which a great deal of current research time is concentrated, particularly in view of the move to Euro VI with its demand for ever tighter emission limits.
The first challenge is mainly due to piston design, with a relatively long distance from piston crown to rings, a small amount of methane can remain unburned in that crevice volume, to be then expelled from the engine. This is known as ‘methane slip’ and is regarded as important. Methane is tightly regulated under proposed Euro VI limits. There are three primary ways of dealing with this; by gas injection regime, thus reducing the gas available early in the induction cycle, by increasing the gas flame propagation properties, or by catalysis of the gas in the exhaust system. The Hardstaff dual-fuel conversion has been designed with an optimised multipoint gas injection system in order to reduce this but clearly going forward more work is required, and being carried out in the areas of gas quality and composition as well as improving methane catalyst efficiency.
The second challenge, related to the first, is the overall loss of efficiency operating on dual fuel as compared to diesel only. In theory, without efficiency loss, cost savings per mile or km using dual-fuel conversions give a relatively short payback period. While the loss of efficiency can reduce savings, thus extending investment payback period, dual fuel still offers significant cost benefits, particularly under certain operating conditions (load/speed etc.). Optimisation of a dual fuel converted engine needs to take account of these and other factors such as, turbo boost, etc. and even from a holistic approach a reprogramming of automatic gearbox change points. Furthermore, these will not necessarily be identical for each operator, route or vehicle.
While the above might be seen as an argument against aftermarket conversion to the benefit of the ‘dedicated dual-fuel engine’ the great advantage of the conversion route is that it allows reversion to diesel only operation in the event of running out of gas. While this may become less of an advantage in the longer term, the relative scarcity of gas availability in Europe means conversion is likely to remain the primary route into dual fuel for several years yet, making further technical research combined with real world demonstration absolutely vital. The low levels of initial demand may not be sufficient to attract R&D budget from major OEM’s, thus if retrofit dual fuel is not available or overly
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demanding emissions limits imposed, the take up of gaseous fuel HDV’s in the EU may only happen at a very slow pace.
2.5.1.8 Legislation Issues
Technical barriers are largely imposed by the standards that are produced to facilitate a regulated market. Legislation therefore is a relevant topic of discussion in the context of this report. The Blue Corridor project presents an ideal opportunity for The Hardstaff Group to showcase and commercialise its existing and future technology throughout Europe, however due to changing standards, it brings with it major issues regarding emission legislation:
• The standard for emission limits for dedicated diesel or gasoline and spark-ignited dedicated gas vehicles under Euro VI was agreed and published some time ago, indeed it had to be in order for the mainstream vehicle producers to be able to plan to comply. • The standard for Euro VI emission limits for dual-fuel diesel / gas, for OEM solutions is agreed and will be published in 2014, to virtually coincide with the introduction of Euro VI generally. • The standard for emission limits for dual-fuel engines, for retrofit solutions, is in the early stages of drafting. Currently this is expected in 2 stages – Euro V 2014/15 and Euro6 in 2015/16, just as the LNG Blue Corridor Project enters its final stages.
Final Euro V retrofit dual fuel solutions only managed to achieve type approval through special mechanisms allowed under the small series approvals process and were somewhat discretionary. What this means is that only dual-fuel or dedicated gas vehicles produced by an OEM will be able to be licensed from 2014, assuming they meet the emissions criteria. Retrofit solutions will not have an applicable standard and thus will officially be an unregulated product, unless via concessions, until 2015/16 at the earliest. If concessions are granted but number levels are set too low this will act as a positive disincentive for companies such as Hardstaff to proceed with the work they have started i.e. to produce a retrofit or non-OEM solution for Euro VI, as numbers will be uneconomic.
Effectively the retrofitters (not just Hardstaff) will be at a disadvantage compared to OEMs in bringing a valuable CO 2 lowering technology to market.
The barrier that existed at Euro V now exists for Euro VI vehicles and may preclude the take up in reasonable commercial quantities until legislation comes into force. It is important to realise however that the retrofit solution will not meet the very tight OEM Euro VI methane emissions limit immediately, due to the engine architecture discussed in earlier sections, but it is expected that technology developments will allow a move towards this level during the period of drafting the standard.
The crucial emission legislation for OEM Gas fuelled Euro VI vehicles will be in place for introduction in 2014. The new Euro VI methane hydrocarbon limit is variable, depending on whether or not gas is part of the fuel mix and if so at the level of substitution for diesel or gasoline. Whether the OEM dedicated gas and dual-fuel vehicles are able to meet these emission levels is, at this stage, unknown, but it is presumed that those OEMs proposing to demonstrate vehicles within the Blue Corridor believe that they will be able to comply.
What is equally clear is that retrofit dual-fuel solutions, such as Hardstaff’s proposed Euro VI solution will not be able to meet the OEM levels for methane emissions at a commercial price until technology is developed that will permit these engines to do so. As discussed, any standard for retrofit Euro VI will not become law until 2015/16 anyway, and therefore any retrofit solution will have to operate under
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an interim mechanism or concession until that time. And due to the uncertainty of any interim mechanism they may not be allowed to operate at all.
Assuming that 80% of the carbon emissions are produced by 20% of the vehicles on the road, it is important that this 20% of the vehicle stock, if converted to dual fuel, is converted with environmental considerations at the heart of the system. This means that some kind of methane catalyst system must be inferred by the legislation; effectively by imposing achievable methane limits. To allow such a system to become a commercial choice as well as the environmental one, systems that do not control methane need to be legislated out of the market; to allow them would inevitably lead to the proliferation of such lower cost systems rather than those which aim to control methane emissions.
The legislators could consider a number of options. Assuming that the 20% most polluting vehicles are in certain weight categories, the legislation could be written as to preclude low cost non-methane control systems from those weight categories. Alternatively they could consider imposing emissions limits which make methane catalyst control systems mandatory across all weight categories.
It seems logical therefore to propose a concessionary interim standard for Euro VI retrofit dual-fuel engines that will acknowledge what is realistically achievable in terms of methane emissions and commerciality at launch, with the aim that it will harmonise more closely with the OEM and new retrofit standard by the date of the latter’s introduction in 2015/16. It also seems logical that the methane limit should be stepped down toward to OEM limits on a time/phased basis, thus providing an impetus for technical progress in that particular field. Any attempt to impose a limit on methane emissions equal to that for OEMs will delay the introduction of retrofit technology for several years, and probably make development unsustainable on the grounds of research cost without short-term return.
2.5.2 Other conversions Clean Air Power
Is a company that developed a Dual-Fuel Engine Management Software which enables heavy-duty trucks to operate on a combination of diesel and natural gas, with no change to the base engine.
CAP (Clean Air Power) is a Tier 1 supplier of dual-fuel system to major European truck manufacturers; the system is called Genesis EDGE. An original patent holder remains with the company.
CAP introduced its systems in the UK and Spain. Below are some CAP achievements:
Sainsbury's Supermarkets Ltd started with a single Genesis in 2008 and a further 5 in 2009. They were a trial customer for the Volvo MethaneDiesel in 2010. In 2012 they converted 49 Volvo FM13s using the Genesis EDGE dual-fuel system
Wiseman Dairies initially ordered 2 Genesis systems in 2007 and a further 20 in 2008. Following a grant from TSB, Robert Wiseman Dairies, collaborating with Chive Fuels, Cenex and MIRA, will, in 2013, trial the use of 40 new warranted dual-fuel 40 ton articulated trucks substituting diesel with natural gas from two upgraded public access liquefied natural gas stations, one in the West Midlands and one in Scotland.
B&Q operating 25 Dual-Fuel trucks incorporating Clean Air Power technology at their facility in Swindon
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Stobard Group ordered 20 OEM Dual-Fuel vehicles in 2012
In 2012, a major global logistics company installed 27 Genesis EDGE systems for their UK contract with NISA
Spain’s HAM Criogénica Group purchased their first Mercedes Axor Genesis dual-fuel in 2007 followed by 10 more Genesis EDGE systems in 2010. In 2012, CAP developed the Renault Magnum variant together with HAM and delivered 62 systems in 2012. In 2013, 20 more systems have been delivered.
Prins Autogas
It is a company from the Netherlands that developed a Dual-Fuel Engine Management Software enabling heavy-duty trucks to operate on a combination of diesel and natural gas, with no change to the base engine.
Figure 2-25 Vehicles converted by Prins Autogas (Source Prins)
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Ecomotive Solutions
Ecomotive Solutions is a company based in Italy that has developed a Dual-Fuel Engine Management Hardware and Software enabling Euro V heavy-duty trucks to operate on a combination of diesel and natural gas, with no significant change to the base engine.
Figure 2-26 Vehicles converted by Ecomotive Solutions (Source: Ecomotive Solutions)
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3 LNG fuel systems Part components from LNG fuel system are described below:
3.1 Systems using saturated LNG tanks 3.1.1 Components of a Vehicle Tank
Figure 3-1 LNG tank (Source Chart) Cryogenic Superinsulation
Each tank is wrapped with multiple layers of insulation, which reflects heat away from the tank. The wrapped inner tank is enclosed by an outer tank and a vacuum is drawn between the walls. This combination of multi-layer insulation and vacuum is called superinsulation, and has nearly double the rating of vacuum only insulation.
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Economizer Regulator
When pressure in the tank rises above a preset number (typically 6 to 9 bar), the economizer regulator vents vapour into the fuel line. This increases vehicle tank hold time to 7 to 10 days and also maximises LNG per gallon mileage performance.
LNG Fill Fitting
Fuel fitting only opens after fuel nozzle is positively locked in place. Fitting closes when nozzle is released to prevent any fuel loss.
Fuel Contents Gauge
Alerts driver or fueller to the fuel levels in the vehicle tank. Fuel gauge can be placed by the vehicle tank or in the truck cab. LNG BC D2.1 Euro V final technical solutions Public
Dual Relief Valves
Each tank has a relief valve set at 230 psi and a backup relief valve set at 350 psi should the first valve fail.
Fill Check Valve
The check valve at the fuel fitting prevents LNG from escaping should the fill fitting fail or if the vehicle is driven off without the nozzle being disconnected.
Product Isolation Valve
Valve shuts off the flow of LNG to the engine when a vehicle is being serviced.
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Excess Flow Valve
Shuts down LNG flow to the engine in case of a fuel line break between the LNG tank and the engine.
In-line Check Valve
Prevents the reverse flow of high-pressure fuel (after vaporization) back into the LNG tank.
Tank Pressure Gauge
Alerts fueller to the actual pressure in the tank. If pressure is too high it can be vented back to the bulk storage tank through the LNG dispensers.
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Overpressure Regulator
Controls the pressure of the fuel to the engine. Typically set at 90 to 140psi depending on the engine.
3.1.2 Filling the LNG Tank
Figure 3-2 LNG tank, fillong process (Source Chart) A. During the filling process, a LNG nozzle is hooked up to a receptacle on the vehicle. Once the connection is made and the dispenser button is pushed, the liquefied natural gas starts to flow through the nozzle and the check valve and into the spray header. B. As the liquefied natural gas is spraying out of the header, the very cold mist starts to condense the slightly warmer vapour in the tank. As the vapour condenses it also contracts in volume, lowering the head pressure within the tank. This process is referred to as “collapsing head pressure.” C. As the collapsing of the head pressure occurs, the fuel liquid level continues to rise until it reaches the spray header. As the liquid level approaches the spray header, the misting has less
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and less effect on the vapour portion of the fuel since the amount of vapour volume is decreasing and the mist does not have as much contact area before coming into contact with the liquid. D. Once the liquid level has reached the spray header, the head pressure quickly rises. The fuelling station senses this and shuts off the fuel supply. A vapour space above the liquid remains in the tank. This is called the ullage space, and is necessary to permit expansion of the liquid as it slowly starts to warm up. For safety, the tank incorporates a check valve and excess flow valve to stop the flow of LNG in the event of a line rupture.
3.1.3 LNG's Path from the Tank to the Engine E. As the engine is started, the pressure from the saturated liquid within the tank pushes liquid natural gas through the liquid line, the fuel supply hand valve and excess flow valve up to the heat exchanger. F. Once the fuel enters the heat exchanger, it is warmed up by the circulating engine coolant. The
heat from the engine coolant causes the liquid natural gas to boil and vaporize. G. All natural gas engines require natural gas to be of a vapour form and within a specified pressure range. The liquid natural gas begins to form a vapour and increases the pressure within the tank therefore eliminating the need for a fuel pump. H. For safety, if the fuel line should break or leak excessively, the excess flow valve will sense an abnormally large rate of fuel flowing past it and will close off to eliminate emptying all of the remaining fuel from the tank.
3.1.4 Pressure Equalization A. If the pressure within the vehicle tank exceeds that of the economizer’s setting, the economizer valve will open and allow the excess pressure to be introduced to the liquid withdrawal stream. B. The process of pulling the vapour from the top of the tank will reduce the pressure within the tank very quickly. When the pressure within the tank drops to the set point of the economizer, the economizer will close, allowing only liquid to be withdrawn. C. The tank is protected against over pressurization by two relief valves. If the vehicle has not been operated for some time, the liquid will take on heat and expand, causing the pressure within the tank to rise. D. The primary relief valve will open and relieve the excess pressure by exhausting the vapour into the atmosphere. For safety, the primary relief valve is plumbed to vent away from the vehicle. E. If the primary relief valve or its plumbing should become obstructed or malfunction, the pressure within the tank would reach the setting of the secondary relief valve. The secondary relief valve would open, relieving the excess pressure.
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Figure 3-3 Indox tank. Support and evaporator integated in the tank 3.2 Systems using cryogenic pumps in the tanks LNG fuel systems using a cryogenic pump in the tank are currently only commercialised by Westport in North America and Australia. This system is described below:
It was specifically designed to work with the Westport HPDI technology. It is the only fuel system available with the Westport 15L engine.
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Figure 3-4 Westport TM 15L Engine&Fuel System – Source Westport LNG fuel for the Westport 15L system is stored in the LNG tank, and drawn out with a unique LNG pump (powered by hydraulic oil from an engine-driven hydraulic pump). The LNG is vaporized—using excess heat from the engine coolant—and exits the tank module at approximately 40ºC and 30 MPa. The warm, high-pressure gas is filtered and passed through an accumulator vessel that dampens pressure fluctuations and provides natural gas for engine start-up.
The Westport LNG tank module is an integrated storage and high-pressure supply module:
• Industry standard vacuum insulated vessel with custom porting • Integral vaporizer, fuelling receptacle • Integrated hydraulically driven reciprocated high-pressure pump
Figure 3-5 Westport TM 15L LNG tank module – Source Westport
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The integrated LNG pump is a hydraulically driven cryogenic pump that pumps LNG to 350 bar. Its single-stage, slow reciprocating design provides good seal life due to slow speeds and LNG super- cooling. The pump and vaporizer are integrated into the tank module.
Figure 3-6 Westport TM 15L LNG pump – Source Westport 3.2.1 Westport iCE PACK™ LNG Tank System The Westport iCE PACK™ LNG Tank System is an onboard LNG tank system customized for spark- ignited engines, and designed to meet the demands of today's trucking fleets by providing increased range, longer hold times and faster fuelling times.
Figure 3-7 Westprot ICE PACK TM LNG tank – Source Westport The Westport iCE PACK LNG Tank System, through a series of sensors, monitors fuel pressure and when needed activates a pump to deliver reliable fuel pressure to the engine. The Westport iCE PACK will always deliver the right amount of fuel, regardless of engine size and operating demands, ensuring peak performance of spark-ignited engines.
The Westport iCE PACK, through its ability to use cold LNG fuel (-150°C or 2 bar), doubles tank hold times from five days to 10 days. Cold LNG provides up to 10% more operating range when compared with warm (saturated) LNG.
When the pressure inside the Westport iCE PACK LNG Tank is high (above 11 bar), vapour pressure “pushes” fuel from the tank to the engine, without activating the pump.
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Figure 3-8 Estport ICE Pack TM LNG Tank System Operating Example with High Tank pressure – Source Westport When the pressure inside the Westport iCE PACK LNG Tank is below 11 bar, the LNG pump is activated, eliminating reliance on tank pressure.
Figure 3-9 Westport iCE PACK TM LNG Tank System Operating Example with low Tank Pressure – Source Westport The Westport iCE PACK was commercially launched in North America in 2013. It is currently available on a variety of leading OEM truck models in North America, including Freightliner, Peterbilt, Kenworth, Volvo and Mack. The product is also suitable for the European market even though it has not been mounted on Euro V or Euro VI trucks at this stage.
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Figure 3-10 Westport iCE PACK TM LNG Tank System Mounted on a Truck – Source Westport
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4 LNG Euro V vehicles 4.1 OEM Iveco Stralis LNG Iveco began the development of a LNG truck in 2004. In 2005 was built the first pilot prototype. This vehicle conducted 5 years of real service working at full capacity, as a refuse collection truck, in Barcelona. The engine specification was similar to an equivalent CNG truck with 270 CV. As the gas from the grid in Barcelona comes from a LNG terminal the performance of both versions was similar.
This test was carried out thanks to the support of the Spanish administration.
Figure 4-1 Iveco first LNG pilot prototype Meanwhile Iveco continued the development of a LNG truck LNG adapted for use on intercity roads.
Several aspects related to the LNG had to be born in mind; the first one to define the working pressure of the engine and the type of system to be used. It was decided to use a tank type of saturated LNG for being the simplest and cheapest solution.
Considering the properties of the saturated LNG, the aim is to work with the lowest pressure of storage, because that means more density of gas and consistently greater range.
This an important point, because each particular natural gas engine needs a specific working pressure, depending mainly on the injection system. For this reason Iveco and FPT reduced the engine working pressure from 9 bar to 7 bar, 8,5 bar in the tank.
The LNG system could be adapted to a truck configuration very different from the refuse truck, the typical NG heavy-duty application until then. For example, the automatic gearboxes could be replaced by a manual gearbox.
A very important task was to search, select, test and define the different elements of the LNG system: tank, filling nozzle, vaporizer and pressure regulator.
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liquid gas
economizer
vaporizer
Figure 4-2 LNG tank Iveco selected from the reduced market of LNG tanks two suppliers for the development, from: Indox CryoEnergy and Chart.
Both suppliers used the same tank system, but different internal and external design, different insulation type: vacuum + multi-layer (Chart) or vacuum + perlite (Indox).
Indox design allowed higher maximum pressure (25 bar vs 14 bar), and a longer time-to-venting was expected. Manufacturing of Indox is in Europe, whereas Chart is in Europa.
Iveco built several prototypes and pilots with both tanks, which were put in real service with selected clients and where special registrations were possible, mainly in Spain and the Netherlands.
Both tanks included their own vaporizer. The receptacle chosen was one from Parker Kodiak, for compatibility reasons.
Figure 4-3 Indox LNG tank
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Figure 4-4 Chart LNG tank
Figure 4-5 2009 Stralis LNG with Indox tank
Figure 4-6 Chart LNG tank
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After analysing several factors, including the opinion of the clients, the Chart tank was chosen. The best configuration of a LNG truck is with two LNG tanks, if the LNG infrastructure covers the route of the vehicle. But this configuration is not possible from the point of view of the shipping of the truck from factory. Until the market for the LNG truck justifies the construction of a LNG station inside the company, it is not possible to serve trucks only with LNG for safety reasons and to allow the self- movement of the vehicle in the transport. For that reason the Stralis LNG was also defined with a CNG system with 4x70 cylinders. When the truck operates in service many clients replace this CNG kit with a second LNG tank to improve the range.
LNG saturated system principle
NG is stored in the tank in a liquid-gas equilibrium state at a determined pressure-temperature determined in the tank filling-up moment.
Pressure itself pumps the liquid, when demanded by engine, to the vaporizer, where it is heated with engine coolant to get it in gas phase, ready to adjust the delivery pressure to the engine and be burnt as in a CNG engine. In fact, the engine burns NG, regardless of the source, whether CNG or LNG.
Due to the low temperature of the liquid, thermal isolating is needed to prevent the boil-off effect (liquid boiling). As this cannot be completely avoided, the economizer allows injecting in gas phase into vaporizer to feed the engine when pressure rises. If the engine is not running and tank maximum pressure is reached, the relief valves open to the atmosphere to keep the pressure under the limits.
So the economizer will keep the pressure-temperature at design working value.
Defining the working pressure:
Limiting values for tank working pressure are mainly engine nominal feeding pressure (now 7 bar, about 5 bar in future) and maximum tank allowable pressure (14 bar for Chart).
Between these two limits a balanced decision must be taken. If high pressure is chosen, liquid phase density will be lower, and the vehicle range will be less. Furthermore, maximum allowable tank pressure will be reached sooner (due to boil-off effect), so time-to-venting will also be reduced (gas wasting).
Taking this into account, the right decision is to define the working pressure near to feeding engine pressure, but a certain overpressure must be present in order to maintain the gas-pump effect, and minimize long gas demanding periods (engine at full load), which may decrease the equilibrium temperature in the tank.
This fact can be explained by the decreasing liquid-phase volume inside the tank, so gas-phase volume increases and pressure decreases. The tank insulation does not allow heat to enter quickly, and therefore the thermodynamic system reacts to maintain temperature and pressure, so the liquid is vaporized until pressure is recovered. But vaporization needs energy, which is taken from the liquid temperature. If long gas demanding time occurs, this vaporization may lead to temperature decrease, and so pressure also decreases.
So 1 or 2 bar overpressure above feeding engine pressure is recommended.
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Stralis LNG
Iveco presented the Stralis LNG truck at The European Road Transport Show of Amsterdam in April 2012. Series production began as detailed below.
Figure 4-7 Commercial presentation of the Stralis LNG Amsterdam April 2012 Iveco sold 15 units in 2012 and 87 units in 2013 of the Stralis Euro V LNG. If the pre-series vehicles and transformation authorized with the Iveco solution are added, nearly 200 LNG Stralis LNG are running currently in Europe; .mainly in the Netherlands and Spain and some in Italy, Belgium and Finland (Bio- LNG).
Iveco included the LNG version in the evolution of the Stralis range in 2014. The Euro VI version of this truck, which includes some modifications, is already homologated, and orders have been open since January 2014 and production will begin in April 2014.
In the 2 nd half of the year a new version with the adaptations to the LNG Amendments of the R-110 that expected to be published in July 2014 will be launched.
The development of the new improvements in LNG engines and vehicles continue in Iveco. A new generation is expected for the end of 2015, not before.
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Figure 4-8 The last Euro V version of the Stralis LNG 4.2 OEM Volvo FM Methandiesel 4.2.1 Features Unlike all other gas-driven trucks the Volvo MethaneDiesel is a 13-litre (460 hp) truck with an explicit environmental profile, developed primarily for regional distribution. But, as opposed to conventional gas trucks, it has the ability to also perform long-haul transports in a cost-effective manner. The qualities of the new Volvo FM MethaneDiesel add unique flexibility to the truck fleet since each truck will offer a substantially larger range of operation compared with traditional gas vehicles. Its unique ability to run on diesel only, if gas supply temporarily is a problem, further adds to its flexibility.
Figure 4-9 The Volvo FM MethaneDiesel truck
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4.2.2 Tank and fuel system LNG/LBG tank contains 280 litres or 540 litres (left side of the vehicle) and diesel tanks: 150, 240 or 330 litres (right side).
Figure 4-10 Illustration of the MethaneDiesel specific components LNG tank, fuel injection system and methane catalyst Normal operating pressure of LNG tank is around 10 bar and normal pressure rise of LNG tank when gas is not being used is between 1–2 bar per day. The LNG in the tank is always slowly warming up and evaporating, forming a vapour layer above the liquid gas in the tank. As evaporation continues, the pressure in the tank rises. This pressure is used to deliver gas to the engine. During normal operation, the pressure of the vapour layer is moderated by the pressure regulator. This ensures that at pressures above 7 bar, both vapour and liquid are drawn from the tank. Below 7 bar, only liquid is used, preserving enough tank pressure to deliver the fuel. Should the pressure of the vapour layer exceed 16 bar, some of the gas vapour is vented to atmosphere via a primary pressure relief valve and the vent stack. In the event of a failure of the primary relief valve a 24 bar secondary relief valve protects the tank from over-pressuring. The tank can be manually vented with the vent hand valve. The tank pressure is monitored with a pressure gauge.
The LNG tank is filled through the filler receptacle. A non-return valve stops LNG returning through the filler receptacle. The LNG tank is fitted with an ullage space to prevent the tank from being completely filled and disabling evaporation. The system can be fitted with gas return nozzle for connecting to the ventilation hose from the fuel pump. The nozzle must be connected to a ventilation hose to enable manual ventilation with the vent hand valve. The LNG (and vapour) passes out of the tank through a hose break valve and flows through a heat exchanger (evaporator), which uses heat from engine coolant to vaporize the liquid gas. From the heat exchanger, the gas passes through a chassis solenoid valve (opened when the engine is running) and the primary filter. The gas pressure is then reduced by a pressure regulator and delivered to the gas injector manifold via a flexible pipe. The gas injectors are opened in MethaneDiesel mode by the ECU to supply metered amounts of gas. The gas passes a mixer ring that mixes the gas with the intake air before being drawn into the cylinders. When the engine
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goes out of MethaneDiesel mode, two gas shut off valves are closed and the gas injectors stop operating. This isolates the gas system from the diesel engine.
Figure 4-11 LNG tank on the MethaneDIesel truck 4.3 Hardstaff Dual-fuel solution Hardstaff existing Euro V Dual-Fuel solutions:
Homologated conversions of diesel engines (Hardstaff)
Mercedes Axor OM457 Euro V (and earlier)
• Dual-fuel conversion available on aftermarket basis • Daimler technical sign off pending • Test bed optimisation project under way
Mercedes Actros OM501 Euro V
• OEM single type approval, Spain and municipality permissions, Germany • Dual-fuel conversion available on aftermarket basis • Daimler technical approval
Mercedes Actros Euro VI
• Dual-fuel conversion under development
Approximately 400 Axor and Actros Euro V converted vehicles in daily use in UK
Volvo D7 Euro V
• Dual-fuel conversion available for off-line production • Small series approval by Swedish Road Authority • Production capability in Sweden
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Approximately 100 FE and FL converted vehicles operating.
General
• Exhaust modified to incorporate methane catalyst • Continuing development of ECU • Extended wiring looms • Flexible natural gas storage systems: o LNG on tractor o CNG on tractor o CNG on trailer, connected with own design umbilical
4.4 Other LNG vehicles 4.4.1 Scania P310 LNG Scania LNG Euro V truck is equipped with a 9-litre natural gas engine featuring 305 CV, five-cylinder Otto cycle, separate spark plugs and ignition coils for each cylinder, Allison fully automatic transmission with torque converter and a retarder.
The Scania is fitted with a double-walled stainless steel LNG tank from Indox with a capacity of 145 kg. The 460-litre capacity allows a range of up to 600 km, with a second (optional) tank on the right side offering a range of up to 1,100 km.
Scania gas engines are available with automatic transmission – Allison for trucks, ZF for buses – with or without integrated retarder.
Figure 4-12 Scania 310 model 4.4.2 Mercedes Econic LNG The Econic semi-trailer truck: environment-friendly and quiet, is also able to accommodate shift work and overnight operations. Ideal for just-in-time transport
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Figure 4-13 Mercedes Econic model 4.4.3 Solbus LNG buses Solbus is a family-owned Polish bus manufacturer and one of Poland’s fastest growing companies. The company has been leading the adoption of LNG as a transportation fuel for buses. Solbus Solicity natural gas buses run on LNG, using a Cummins ISL G EEV 320 engine and a Chart Ferox 365 litre fuel tank. 4
Figure 4-14 A Solbus LNG bus in Warsaw – Source Solbus
4 Source: http://www.bluecorridor.org/ngvs/natural-gas-buses/solbus-brings-natural-gas-buses-to- polands-cities/
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Figure 4-15 Solbus Solcity LNG in Hanover’s IAA show 2012 – Source Solbus With a range of 400 kilometres in city traffic, which can be extended to more than 500 kilometres by installing larger LNG tanks, Solbus’ LNG bus is a proven and reliable choice for transportation.
In 2012, Solbus introduced the Solbus Solcity 12 LNG bus to several Polish transportation markets, with the following results:
• Solbus’ natural gas buses emitted 25% less carbon dioxide and 75% less carbon monoxide than petrol-fuelled engines. • Solbus’ products were able to comply with the European Union’s Euro VI ecological standards without any need for additional filtering, with particulate matter emissions reaching almost zero.
• The Solbus Solcity 12 natural gas buses also met the Euro VI standards calling for limited nitrogen oxide emissions. In October 2013, Solbus launched Europe’s first 11 LNG city buses in the Polish city of Olsztyn 5. Solbus, its distribution partner Lider Trading, and GAZPROM Germania won a public tender issued by the city of Warsaw and were able to convince the municipal transport company of Warsaw of the environmental and cost benefits of using natural gas as a motor fuel. Solbus will supply MZA with innovative, modern LNG-powered city buses.
5 Source: http://www.ngvaeurope.eu/gazprom-germania-and-solbus-launch-lng-market-in-poland
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4.4.4 Outside of Europe
In North America
There are several thousands of LNG HDVs running on the North American roads. These vehicles are available from major truck OEMs and primarily equipped with Westport 15L or Cummins Westport natural gas engines.
The Westport 15L engine is commercialised in Peterbilt and Kenworth OEMs’ LNG HD trucks (more than 1,200 LNG trucks).
The Cummins Westport ISL G engine is also very common in North American LNG trucks, primarily in medium and heavy-duty truck and tractor applications. The ISL G is available as a factory option for LNG trucks from leading truck manufacturers including Kenworth, Volvo Trucks, Freightliner, Navistar and others.
The new Cummins Westport ISX12 G natural gas engine, launched in North America in 2013, with a displacement of 11.9 litres and up to 400 hp and 1450 lb-ft of torque, is already successful for LNG trucks as well. It is available as a factory option from major truck OEMs such as Peterbilt, Kenworth, Freightliner, Volvo Trucks, Mack Trucks and Navistar.
In China
China became the largest LNG truck market in the world in 2012. China has had the largest annual sales for LNG trucks in 2012, with 3,020 vehicle sales 6.
LNG trucks are available in China from a number of OEMs including Shanqi, Sinotruk, Dongfeng (DFM), Baotou Beiben, FAW and others.
Chinese heavy-duty LNG trucks are primarily using 10L and 12L spark-ignited natural gas engines. Weichai Westport, Yuchai and Sinotruk are the major manufacturers of heavy-duty natural gas engines. Weichai Westport WP10 and WP12, Yuchai YC6MK and Sinotruk WT615 are among the most common engine models for this vehicle category. 7
6 Source: http://www.hdma.org/Main-Menu/HDMA-Publications/Diesel-Download/January-14- 2014/Nearly-1-Million-CNGLNG-Trucks-and-Buses-Will-Be-Sold-from-2012-to-2019.html 7 Source: Westport analysis based on data from China Automotive Technology and Research Center, www.chinaev.org
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5 Conclusions 5.1 LNG: analysis for use in HD vehicles 5.1.1 Advantages: It has much higher fuel density then CNG: approximately half that of diesel and almost three times that of compressed natural gas. If vehicle range is an issue and storage space is limited then LNG/LBM has this advantage.
LNG/LBM can be transported over larger areas where a gas grid is not available to reach customers that have been hard to reach before. LNG/LBM can be fuelled in the liquid phase or evaporated and compressed as CNG.
5.1.2 Disadvantages: The fuel is less stable so has limited shelf life of storage on a vehicle, if not operated. Unless actively handled the fuel warms up and is vented to the atmosphere to prevent over pressurization, which leads to loss of fuel and a potential shift in CV for the remaining fuel in the tank; hence it is most suitable for vehicles that are being used for quite long distances every day.
LBM-LNG does not smell of gas as it contains no odorant and so gas detection has to be used to find a leak.
Requires safety precautions when filling a vehicle.
Currently, there are only the Volvo FM and Mercedes Econic vehicles with LNG Storage and so, in all the other cases, the LNG has to be made into CNG or vehicles have to have conversions to fit LNG tanks.
High-energy consumption when producing LNG/LBM compared to CNG.
High cost for producing LBM.
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Figure 5-1 Positive and negative LNG factors 5.1.3 Compatibilities: The aim of this European project is to analyse the feasibility of LNG trucks running across Europe. For that, it is necessary to have a strong enough structure. Different matters have to be taken into account to make the project feasible such as working pressure in each truck, nozzle used in each tank as well as the gas quality. These features have to be compatible with that provided in the European gas network.
Vehicle LNG filling pressure (bar) Receptacle Special demands on fuel
Volvo MethaneDiesel 6 - 10 Parker Kodiak MN(CARB) > 90 (alt. 85)
Iveco Stralis 8 - 10 Parker Kodiak MN (AVL) >70
Mercedes Hardstaff 8 - 10 Parker Kodiak
Mercedes LNG 20 JC. Carter
Scania LNG (Euro V) 20 JC Carter
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References List of figures Figure 1-1. Impression of the LNG Blue Corridors ...... 5 Figure 2-1 (Source NGVA Europe) ...... 7 Figure 2-2 NGV available on the market – Trucks (Source NGVA Europe) ...... 8 Figure 2-3 Dual fuel retrofitted trucks avalaible through official dealer network ...... 8 Figure 2-4 General overview of technologies used. (Source:CRF) ...... 10 Figure 2-5 Otto Cycle Stoichiometric combustion (Source CRF) ...... 11 Figure 2-6 Otto Cycle lean burn (Source CRF) ...... 12 Figure 2-7 Explanation of Rich & Lean – Burn combustion ...... 12 Figure 2-8 Iveco – FPT Cursor 8 GNC engine (Source Iveco) ...... 13 Figure 2-9 (Source FPT) ...... 14 Figure 2-10 ISL G Engine – (Source Westport) ...... 15 Figure 2-11 Cummins Westport Spark Ignited Stoichiometric Technology with cooled EGR – (Source Westport) ...... 15 Figure 2-12 ISL G Euro V Ratings and Specificatons (Source Cummins Westport) ...... 16 Figure 2-13 OC9 Euro V/EEV Ratings (Source Scania) ...... 17 Figure 2-14 OC9 Euro VI/EEV Ratings (Source Scania) ...... 18 Figure 2-15 OM906 Natural Gas Euro V/EEV Ratings (Source Mercedes Benz) ...... 19 Figure 2-16 Diesel cycle with natural gas fumigation (Dual Fuel) (Source CRF) ...... 20 Figure 2-17 Volvo FM MethaneDiesel multipoint gas injection system ...... 20 Figure 2-18 Diesel cycle with natural gas direct high pressure (300 bar) injection (Source Westport).... 23 Figure 2-19 Westport HPDI Injector Tip Assembly (Source Westport) ...... 24 Figure 2-20 Westport 15L engine (Source Westport) ...... 24 Figure 2-21 Westport 15L engine ratings (Source Westport) ...... 24 Figure 2-22 Westport 15L engine speed and torque (Source Westport) ...... 25 Figure 2-23 Westport 15L engine specifications (Source Westport) ...... 25 Figure 2-24 Weichai Westport WP12HPDI Engine (Source Westport) ...... 26 Figure 2-25 Vehicles converted by Prins Autogas (Source Prins) ...... 33 Figure 2-26 Vehicles converted by Ecomotive Solutions (Source: Ecomotive Solutions) ...... 34 Figure 3-1 LNG tank (Source Chart) ...... 35 Figure 3-2 LNG tank, fillong process (Source Chart) ...... 39 Figure 3-3 Indox tank. Support and evaporator integated in the tank ...... 41 Figure 3-4 Westport TM 15L Engine&Fuel System – Source Westport ...... 42 Figure 3-5 Westport TM 15L LNG tank module – Source Westport ...... 42 Figure 3-6 Westport TM 15L LNG pump – Source Westport ...... 43 Figure 3-7 Westprot ICE PACK TM LNG tank – Source Westport ...... 43 Figure 3-8 Estport ICE Pack TM LNG Tank System Operating Example with High Tank pressure – Source Westport ...... 44 Figure 3-9 Westport iCE PACK TM LNG Tank System Operating Example with low Tank Pressure – Source Westport ...... 44 Figure 3-10 Westport iCE PACK TM LNG Tank System Mounted on a Truck – Source Westport ...... 45 Figure 4-1 Iveco first LNG pilot prototype ...... 46 Figure 4-2 LNG tank ...... 47 Figure 4-3 Indox LNG tank ...... 47 Figure 4-4 Chart LNG tank ...... 48 Figure 4-5 2009 Stralis LNG with Indox tank ...... 48 Figure 4-6 Chart LNG tank ...... 48 LNG BC D2.1 Euro V final technical solutions Public
Figure 4-7 Commercial presentation of the Stralis LNG Amsterdam April 2012...... 50 Figure 4-8 The last Euro V version of the Stralis LNG ...... 51 Figure 4-9 The Volvo FM MethaneDiesel truck ...... 51 Figure 4-10 Illustration of the MethaneDiesel specific components LNG tank, fuel injection system and methane catalyst ...... 52 Figure 4-11 LNG tank on the MethaneDIesel truck ...... 53 Figure 4-12 Scania 310 model ...... 54 Figure 4-13 Mercedes Econic model ...... 55 Figure 4-14 A Solbus LNG bus in Warsaw – Source Solbus ...... 55 Figure 4-15 Solbus Solcity LNG in Hanover’s IAA show 2012 – Source Solbus ...... 56 Figure 5-1 Positive and negative LNG factors ...... 59
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