Småskalig ångteknik för värmeåtervinning inom Stålindustrin med modern ångmotor
1 Why Steam Engine again ??
Rankine power cycles is more fuel flexible than any other power cycles but in the small scale power out put range of 10 kW – 1000 kW steam turbine is not best suited to offer high efficient and cost effective steam power. Besides to being fuel flexible modern steam engine offer cost effective recovery of waste heat below 1 MWel.
2 Novel High Performance Steam Engines High Specific power ( kW/kg,kW/SEK,kW/m3)
3 RANOTOR Corp.
Is founded by the former project leader for SAAB SCANIA’s steam engine project during the 70’s RANOTOR resumed to work 1983 and has developed the technology on and off since then with industry and universities
Jernkontoret 8 Maj 2015 4 Rankine verkningsgraden
휂
80 %
휂 70 % Carnot
60 % 500 bar 200 bar 100 bar 50 bar 50 % 20 bar 10 bar
40 %
휂Rankine 30 %
Tcondensor =20 ̊ C 20 %
500 ̊ C 1000 ̊ C 1200 ̊ C 5 Components in a Steam Engine System
Steam Generator
Reciprocating Steam piston steam engine Buffer
Air or water cold condenser
6 What does it takes to realise a modern high performance steam engine….?
•High expansion ratio= small clearance volume •High shaft-speed •Oil-free operation
Jernkontoret 8 Maj 2015 7 What kind of expander ?
•Turbine ? Piston engine best technology •Screw ? 250 bar + 450 °C •Scroll ? 6000 rpm •Vane ? 1200 kW/litre displacement
8 Efficiency
Modern steam Torque [Nm/liter] Torque [Nm/liter] engine has high efficiency compared to steam turbine below 1 MW . About 30 % At + 500 C steam rpm rpm temperature
9 Very high specific power kW/liter, kW/kg,kW/SEK Ten times higher power density (kW/liter) than conventional internal combustion engine
10 RANOTOR Steam Generator Micro tubes and laminar flow
Low cost normalised to power compared to conventional boiler and suitable to adapt on pipes Very low pressure drop
11 Pinchen
600 600 H20 H20 500 500 100 bar 250 bar
400 400
Exhaustgas Exhaustgas 300 300
Steam Steam Temperature Temperature C Temperature 200 200 Exhaust gas Exhaust gas outlet temp outlet temp 100 100 + 198 C + 218 C 0 0
Temperature profile HRSG Temperature profil HRSG H20 ( 80 %) & NH3 (20 %) H20 ( 80 %) & NH3 (20%)
600 600 100 bar 250 bar 500 500
400 400 Exhaust Exhaustga gas 300 300 NH3-H20 s 200
200 Temperature C Temperature Temperature C
100 + 138 C 100 + 146 C
0 0
12 ORC
13 CO2 steam engine
180 Solar Driven Carbon Dioxide Transcritical Power Cycle c
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100 220 bar 5
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[ 120 bar
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a 0 g 40 bar 0.2 0.4 0.6 0.8 -20 -1.75 -1.50 -1.25 -1.00 -0.75 -0.50 s [kJ/kg-K] 14 15 WHR ( Waste Heat Recovery ) in steel industry
RANOTOR HRSG (Heat Recovery Steam Generator) suitable to adapt on pipes with waste heat. In-line with existing pipes Pipe diameter 10 - 2000 mm Small pipe diameter less insulation due to cold gas Cost
Cold gas 50 -200 C 5000 Hot gas 200-600 C 200-600 C SEK/kWel Condenser , Steam 20 -220 bar Water or air 150 -500 C cooled Steam engine
16 Steam Buffer . Thermal energy storage for recovering of intermittent waste heat in steel industry
Steam Buffer makes it possible to recover intermittent waste heat generation and store it for a couple minutes up to 1-3 hours
Steam buffer might be manufactured by slag from steel industry processes.
Large market potential outside steel industry as storage in electric grid and concentrating solar power
17 Steam Buffer vs Electric Battery
Steam Buffer peak shaving rather than storing large amount of energy for long periods
Energy storage kWh/kg kWh/l kW/kg kW/l Capital Cost Power SEK/kWh SEK/kW
Lithium-Ion ( 휂 = 90 % ) * 0,090 0,045 0,3 0,3 3 5000
Steam Buffer (휂 = 30 %) ** 0,025 0,20 5 15 0,04 2
*Nissan Leaf **Steam Buffer material from waste material ( Slagg)
18 Problem 1 och Projektförslag 1 Problem 1. Stålindustrin har spillvärme vid höga temperaturer distribuerat inom sina anläggningar och storskalig ångteknik med ångturbin för spillvärmeåtervinning är sällan möjlig .
Projektförslag 1 Demonstrera en Spillvärmeåtervinnings (WHR) installation för ett mindre flöde av spillvärme på 400-500 C Storlek ungefär 40 kW spillvärme vid 400-500 C , Eleffekt 10 kW. Målet är att sedan kunna skala upp denna WHR upp till 1 MWel. Total kostnad 2,8 MSEK + Installationskostnad och utvärdering Projekttid 2 år
19 Problem 2 och Projektförslag 2 Kortidslagring av höga temperaturer
Teoretisk studie om korttidslagring av satsvis producerad spillvärme med en ångbuffert som används senare i ångmotorn
Teknisk , ekonomisk analys av möjligheterna att använda slag som material,
Projektkostnad ?
Projekttid 1 år
20