Natural Refrigerant Alternatives for the Industrial Marketplace
Newark, N.J., August 24, 2016
Andre Patenaude C.E.T. Antonio De Lourdes
Director – CO2 Business Development Senior Project Engineer (R&D) Emerson Climate Technologies Vilter Manufacturing, Emerson Climate Technologies Agenda
Why invest in natural refrigerants?
Ammonia applications
Key industrial refrigeration trends
CO2 system architectures
Strategies for warm ambient operation
Summary Why Invest in Natural Refrigerants? Low-GWP Refrigeration?
Step 1: Elimination of ozone-depleting refrigerants (CFC and HCFC) Step 2: Phase-down of global-warming refrigerants (HFC)
Step 3: Ramp-up of CO2 commercial refrigeration equipment
Step 1, completed: Step 2, ongoing: Step 3, ongoing: Thinning of the ozone layer global warming damage natural refrigerants
caused by CFC and HCFC caused by HFC CO2, propane, ammonia (banned) (phased down / usage bans) (ramping up)
CFC = Chlorofluorocarbon HCFC = Hydrochlorofluorocarbons HFC = Hydrofluorocarbons Aggressive European Measures to Reduce and Eliminate HFCs Global Warming Potential
R-404A Equivalent Threshold vs. CO2
GWP of 3,922
8 oz of R-404A = Global Regulations Confusing Time for End Users 2015 Was Warmest Year Since 1880, – USA Today Article, 1/20/16
• COP21 Meeting in Paris, 12/2015 • Nations agreed to limit global temperature increase to 2 °C • Countries to update pollution reduction pledges by 2020
This means reducing emissions by 40–70% by 2050 compared to 2010! U.S. Environmental Protection Agency (EPA)
• Slide from Tom Land, U.S.EPA, ATMOsphere America, June 17, 2016 Alternatives for Refrigeration Applications
A1 – Non-flammable A3 – Flammable Qualitative; not to scale B2L – Toxic, mildly flam. Pressure A2L – Mildly flammable or capacity CO2
R-446A, R-447A, ARM-71a R-410A R-32/HFO 400-675 R-32 like Blends R410A R448A R-444B = L20 R449A R404A L40, DR7 R449B R22 R507A NH3 ~300 ARM-20b R-404A & R407A <150 R32/HFO Blends < 1500 R-407/22 R407C R32/HFC/HFO (3922) like R-455A (HDR110) R407F, R452A = XP44 R290 DR3 Blends ARM-35 ARM-20a
R-515A R-134a HFO 1234yf HFC/HFOR450A = N13 ~600 like HFO 1234ze Blends R513A = XP10 ARM-42 R134a R-123 like DR2, N12, ARC 1 (v. low pr.) 0 500 1,000 1,500 2,000 GWP level System Architecture Landscape
HFC or natural HFC and/or natural booster / high stage CO2 (no CO2) (no CO2) CO2 subcritical system CO2 transcritical system Single stage High stage
CO2-NH3 (or HFC) cascade system
Booster Volatile brine CO2 booster transcritical Holistic Facility Approach Can Minimize “Unintended Consequences”
Key variables Stakeholders Trends
Lack of technicians, Toxicity, flammability, Legal, operations performance specs and Equipment working pressures service contracts
Utility incentives, Heat transfer, Energy mgr., continuous Energy latent heat design eng. commissioning, integrated HVACR
Revenue, first cost, Millennials, CEO, merchandising, finance Economics total cost of ownership fresh, urban stores
CO emissions, climate Natural refrigerants, 2 Sustainability officers Environment change regulations Refrigerants: Impact Comparison
R-290 R-744 R-717 Refrigerant R-404A R-507A R-22 Propane CO2 Ammonia
Ozone depletion potential (ODP) 0 0 0.04 0 0 0
Global warming potential 3,700 3,800 1,810 3 1 0 (GWP)
Safety group A1 A1 A1 A3 A1 B2
Reference: ASHRAE Handbook Ammonia Applications Ammonia Applications
• Food and beverage processing: – Dairy, meat processing, breweries, baked goods, frozen foods • Refrigerated cold storage • Recreational ice: – Hockey rinks, curling, ice skating paths – Olympic speed skating, ski jump, bobsled tracks • Ground soil freezing, mining HVAC • HVAC, district heating and cooling, heat pumps Ammonia Pros
Cost-effective • Ammonia systems cost ~10–20% less than competitive systems using HCFCs and HFCs • Less refrigerant required, smaller pipes required due to less mass flow: over nine times more energy content (Btu/lb) than HFCs • Up to 25% more efficient in energy usage • Excellent refrigerant for heat recovery • Low-cost refrigerant and oils: Reference: ASHRAE Handbook – Mineral and semi-synthetic oils • Low-cost refrigerant and oils: – Mineral and semi-synthetic oils Ammonia: A Natural Refrigerant
Natural refrigerant, environmentally friendly: • One of the most abundant gases in the environment • Exists all around us (air, water, soil, produced by our kidneys) • Approx 1.7 times lighter than air • Breaks down rapidly in the environment
• NH3 (R-717): Nitrogen and hydrogen
• Ozone-depletion potential (ODP) = 0 • Global warming potential (GWP) = 0 N Reference: ASHRAE Handbook
Human production: 198 million tons annually (2012) • Second-most produced chemical (after petroleum) • ~80% is produced for fertilizer
• NH3 R-717 refrigerant 99.98% pure ~ 2% of H total production
Reference: ASHRAE H • Cheap, affordable refrigerant Handbook
H 150 Years of Ammonia Refrigeration
Well known: • Ammonia used for more than 150 years in refrigeration • 1850s in France, 1860s in U.S., first patents in 1870s • Consistently used for large industrial refrigeration for over 100 years • Most common refrigerant for food and beverage production, cold storage, recreational refrigeration • Proven safe track record Key Industrial Trends Key Industrial Refrigeration Trends
• Safety and environmental requirements – OSHA requirements – Low-charge ammonia systems – Moving ammonia out of occupied spaces
– Cascade systems using CO2 in the low stage
– Booster transcritical CO2 architecture for MT and LT
– Increased use of R-744 (CO2) and a volatile secondary fluid
• Increased emphasis on total cost of ownership – Equipment cost – Maintenance costs
– Energy cost (improved performance of CO2 at LT such as -40 °F) Key Industrial Refrigeration Trends
• Safety and environmental requirements – OSHA requirements, 10,000-lb threshold
The burden of compliance will continue to be significant, with OSHA’s National Emphasis Program (NEP) inspections, audits and regulation changes related to the OSHA 1910.119 PSM program and the U.S. Environmental Protection Agency’s (EPA) 40 CFR Part 68 Risk Management Plan.
PSM programs (process safety and risk management) Key Industrial Refrigeration Trends
• Safety and environmental requirements – OSHA requirements – Low-charge ammonia systems Key Industrial Refrigeration Trends
• Safety and environmental requirements – OSHA requirements – Low-charge ammonia systems – Moving ammonia out of occupied spaces Key Industrial Refrigeration Trends
• Safety and environmental requirements – OSHA requirements – Low-charge ammonia systems – Moving ammonia out of occupied spaces
– Cascade systems using CO2 in the low stage Key Industrial Refrigeration Trends
• Safety and environmental requirements – OSHA requirements – Low-charge ammonia systems – Moving ammonia out of occupied spaces
– Cascade systems using CO2 in the low stage
– Increased use of R-744 (CO2) and a volatile Contained in secondary fluid equip room
Med-temp
Low-temp Ammonia Evolution: The Future
Ammonia technology trends: • Lower-charge systems, critically charged systems – DX ammonia increasingly possible thanks to electronic controls, valves
• Combined ammonia / CO2 cascade • Ammonia / pumped glycol secondary Med-temp
• Ammonia / pumped CO2 secondary • Consistent development of ammonia compressors and equipment … • Removes ammonia from occupied space
Low-temp CO2 System Architectures CO2 System Architectures — Booster vs. Cascade vs. Secondary
Transcritical Secondary Cascade booster
CO2 DX
CO2 DX
CO2 DX CO2 Secondary System — Schematic
The CO2 would typically be cooled to -20 °F (200 psig) for the LT load +20 °F (407 psig) for the MT load The high-stage system is a simple chiller type system, typically running on an HFC or HC or ammonia.
+20 °F
-40 °F CO2 pumped as volatile brine
CO2 direct expansion Metro Distribution Centre, Laval, QC: Ammonia / Secondary CO2 System
Facility • 240,000 square foot cold storage warehouse • 1000 TR ammonia refrigeration with efficient Emerson / Vilter single-screw compressors
• Distributed CO2 brine throughout the building Emerson solution • Vilter compressors delivered superior part-load efficiency • Expensive VFD drives would have been required with competitor’s twin-screw compressors End user benefits • Reduced ammonia charge • Lower compressor and facility energy costs • Non-ozone depleting refrigerants with zero global warming potential • Vilter dual-slide valve technology avoids more than $100,000 of compressor VFD drives What About CO2? R-744 vs. HCFC/HFC
R-744 HFC / HCFC Impact on R-744 Systems
Global warming potential 1 1,300 to 4,000 Future proof Ozone-depleting potential 0 0 for HFC / high for HCFC Future proof Saturation pressures Higher Lower Additional safety design Operating pressures Higher Lower Specialized components Standstill pressures Higher Lower Relief valves/tanks, etc. (Power outages) Rapid pressure rise Lower Pressure relief venting Inert gas Yes Yes Copper may be used Flammability A1 A1 Not flammable Toxicity No No Asphyxiate in high concentrations Odor None None Leak detection required Volumetric mass flow Higher Lower Smaller tubes and compressors Heat transfer Higher Lower Better thermal efficiency High ambient performance Lower Higher System design to compensate Low ambient performance Good Good Subcritical cascade favorable Cost per pound Low Higher Economical Complexity of systems Higher Lower Higher first cost, training and experience Adoption Low Higher Higher first cost Legislation / regulations Low Higher Long-term viability R-744 Provides Many Benefits Over HFC Options. Pressure-Temperature Relationship Pressure-Enthalpy Diagram, CO2
Liquid and gas density are the same ONLY at critical point.
https://www.youtube.com/watch?v=-gCTKteN5Y4 Climatic Impact of CO2 System Architectures Industrial CO2 Use – New Space
Transcritical
Secondary Selecting the Best System — Booster vs. Cascade vs. Secondary
Transcritical Secondary Cascade booster
CO2 DX
CO2 DX
CO2 DX Introduction to Cascade — Simple Systems
High stage Simple cascade system comprises: (HFC or ammonia) • Low stage provides the cooling load
It uses CO2 and is always subcritical • High stage absorbs heat from the
condensing CO2 at the cascade HX
• CO2 condensing temperature is always below the critical point • High stage is usually a simple, close- Low stage coupled system CO2 • Typically applied in warm climates NH3/CO2 Cascade
• Move NH3 out of occupied space • Improved efficiency Primary stage • Regulatory NH compliance 3 MT • Natural refrigerant
25 °F = 440 psig Low-temp DX — CO LT 2
-30 °F = 163 psig New CO2 Subcritical Open Drive
• Vilter – division of Emerson Climate Technologies • Founded in 1867 in Wisconsin • Currently in Cudahy, Wis. • Products include: – Recips, single screws, packaged systems for: • Refrigeration, heat pumps • Smart vapor management, gas compression for CHP
Package systems Single screw SVM unit 550 Series 552 Test Site: The Helix, Innovation Center Dayton, Ohio (Startup Sept. 15)
Combined circuit on a common skid with two cylinder compressors working in parallel to provide 50 tons at -35 °F SST 25 °F SCT
Ability to test at “real” conditions Development of the HP Reciprocating Compressor
Vilter 552 Vilter 554 Vilter 556 Vilter 558
1,800 RPM 1,800 RPM 1,800 RPM 1,800 RPM
CFM 56 112 168 224
Capacity 48 97 145 193 -30 °F SST/23 °F (tons) SDT BHP 56 112 167 223
Capacity 23 46 69 92 -58 °F SST/23 °F (tons) SDT BHP 48 96 145 193
Testing stage Prototype Production status Design stage Design stage (Helix) stage Selecting the Best System — Booster vs. Cascade vs. Secondary
Transcritical Secondary Cascade booster
CO2 DX
CO2 DX CO2 DX Transcritical Systems Can “Transition” From Subcritical to Supercritical CO2 Transcritical Booster Operation Strategies for Warm Ambient Operation
Low-GWP Climatic Impact of CO2 System Architectures Time Spent in Transcritical
Atlanta, GA Toronto, ON
1,020 hrs/yr 202 hrs/yr w/std. gas cooler w/std. gas cooler
9 hrs/yr w/adiabatic gas cooler Five Ways of Improving Efficiencies in Warm Ambient Regions
• Spray nozzles
• Evaporative or adiabatic gas coolers
• Parallel compression
• Sub-cooling
• Ejectors Supermarket LCCP Analysis
Annual Energy LCCP LT = Low-temperature Min Cond: 50F MT = Medium-temperature DX = Direct expansion LCCP = Life cycle climate performance
Min Cond: 70F
Min Cond: 70F
Min Cond: 70F
Assumptions LT load: 384 MBTU MT load: 1,250 MBU Leak rate assumptions: 15% for all systems Note: 15% is probably high for the ammonia systems. Even if we use 0% it will not change the results, as the GWP for ammonia is 0.
Electric generation factor: 1.5 lbs CO2/kWh Ammonia system was assumed to be single-stage with no subcooling. Summary of Options
100% ammonia system
Ammonia CO2 transcritical booster system Compressor
CO2 pumped as volatile brine Low-temp only
Ammonia/CO2 cascade with MT pumped secondary
Ammonia +20 °F Compressor
-40 °F CO2 pumped as CO2 pumped as volatile brine volatile brine Medium-temp CO2 direct Medium-temp only expansion Low-temp Thank You!
Questions?
For further details, contact
[email protected] [email protected] 519-717-5282 414-486-2634
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