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 η 80 % 70 % η Carnot 60 % 50 % 500 bar 200 bar 100 bar 50 bar 20 bar 10 bar 40 % 30 % 20 % η Rankine T condensor =20 C 500 C 1000 C 1200 C 5
Components in a Steam Engine System Steam Generator Steam Buffer Reciprocating piston steam engine 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? Screw? Scroll? Vane? Piston engine best technology 250 bar + 450 C 6000 rpm 1200 kw/litre displacement 8
Efficiency Torque [Nm/liter] rpm Torque [Nm/liter] rpm Modern steam engine has high efficiency compared to steam turbine below 1 MW. About 30 % At + 500 C steam 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
Temperature C Temperature C Temperature C Temperature Pinchen 600 500 400 600 H 2 0 H 2 0 100 bar 500 400 250 bar 300 Exhaustgas Steam 300 Exhaustgas Steam 200 100 Exhaust gas outlet temp 200 100 Exhaust gas outlet temp 0 + 198 C 0 + 218 C Temperature profile HRSG H20 ( 80 %) & NH3 (20 %) Temperature profil HRSG H20 ( 80 %) & NH3 (20%) 600 500 400 300 200 100 0 100 bar Exhaust gas NH3-H20 600 500 400 300 200 + 138 C 100 + 146 C 0 250 bar Exhaustga s 12
ORC 13
CO2 steam engine T [ C] 180 140 100 60 20 Solar Driven Carbon Dioxide Transcritical Power Cycle c 0.2 340 bar 0.0017 220 bar 120 bar 100 bar b 60 bar a 40 bar g 0.4 0.6 0.8-20 -1.75-1.50-1.25-1.00-0.75-0.50 s [kj/kg-k] 0.0057 d 0.019m3/kg 0.01 14
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WHR ( Waste Heat Recovery ) in steel industry Pipe diameter 10-2000 mm Hot gas 200-600 C Steam 20-220 bar 150-500 C Steam engine RANOTOR HRSG (Heat Recovery Steam Generator) suitable to adapt on pipes with waste heat. In-line with existing pipes Small pipe diameter less insulation due to cold gas Cold gas 50-200 C 200-600 C Condenser, Water or air cooled Cost 5000 SEK/kWel 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 SEK/kWh Power SEK/kW Lithium-Ion ( η = 90 % ) * 0,090 0,045 0,3 0,3 3 5000 Steam Buffer (η = 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