CHP: Technology Update The Organic Rankine Cycle (ORC)

Transcription

1 1 2 CHP: Technology Update The (ORC) ing. Bruno Vanslambrouck, Howest, dept Masters Industrial Sciences Laboratory of Industrial Physics and Applied Mechanics Contence The (Organic) Rankine Cycle Working Fluids Conclusions Economic information Our ORC related activities

2 The Rankine Cycle Steam turbine installation in a power station Electrofilter 5. Transformer 2. Boiler 6. Condensor 3. Steam turbine 7. Cooling tower 4. generator Source: Electrabel The Rankine Cycle E-production from recovered heat of a gasturbine exhaust using a Rankine Cycle Source: Electrabel

3 The Rankine Cycle 5 T-s diagram for a working fluid Rankine cycle with superheated steam Carnot efficiency: The Rankine Cycle 6 Working fluid: usually water Advantages: cheap, widely available non toxic high heat capacity: excellent medium for heat transport chemical stable: less material requirements low viscosity: low friction losses Disadvantages: due to low condensation t : very low pressure, high specific volume, big installations needed (turbine, condensor ) high pressure drop to become a high enthalpy drop: expensive multi stage turbines needed expansion has to start in the superheated area to avoid too high moisture content after expansion: need of a high t - heat source but very partically use because of this: efficiency loss and limited suitability to waste heat recovery

4 The 7 Disavantages water probably to correct using other working fluids, mostly of organic origin: (ORC) Used are: Toluene, butane, pentane, ammonia, refrigeration fluids, silicone oils in the T-s diagram Organic medium The 8

5 The 9 10 ORC Working Fluids Wet fluid Dry fluid Isentropic fluid superheating required superheating efficiency higher vaporization heat at lower pressures evaporation requires a lot of heat or high pressures remains superheated after expansion of saturated vapor superheating unnecessary superheating efficiency superheating unnecessary recuperator unnecessary best choice for ORC from this point of view

6 ORC Working Fluids Power production from industrial waste heat 12

7 13 14 Electrical efficiency = ca 16% if waste gases are cooled down to 120 C

8 Exhaust heat recovery on stationary combustion engines or gas turbines Ca 10% increase of electrical output without extra fuel Economical attractive on engines using renewable fuels (landfill gas, biogas, vegatable oils ) because of governmental support (Green Certificates). Simple PBT of 3 years calculated. Possibility to upgrade old (build before 2002) cogeneration units with respect to CHP certificates by adding an ORC (increase of relative primary energy savings with 5 %). Very short PBT if feasible (1-2 years). Because of high temperature exhaust gases, a steam turbine can be considered on bigger plants Some ORC s are adapted to use jacket cooling water heat Ex: 150 kw ORC by Tri-O-Gen (Nl) Electricity 1550 kwe Exhaust gas (510 C) 150 kwe Engine cooling LT heat Exhaust gas (180 C) (585 kwth, incl losses)

9 ORC integration in an (existing) CHP: CHP Greenhouse 180 C Recuperator Boiler 325 C Turbine Flue gas T > 350 C 760 kw th Generator Inverter 165 kwe 400 V Main feed pump Working fluid: Toluene Pre-feed pump 50 C 600 kwth 35 C

10 19 20 ORC on exhaust gases 2 MW Deutz gas engine Roses farm Olij, De Kwakel The Netherlands Tri-O-Gen B.V. Nieuwenkampsmaten DE Goor Nederland Range: TG30(+) 30 kw; TG60(+) 60 kw Specific designed to recover biogas engine heat (+ means integrated use of engine jacket cooling). Fits on biogas engines in the range kw. Heat source: from 230 C (TG30/TG30+) from 270 C (TG60/TG60+) Cooling source: 30 C or up to 80 C (CHP-version) Heinrich-Hertz-Str Unna Germany

11 21 Maxxtec new small series Model 60 Model 80 Model Waste heat source: Thermal need 375 kwth 520 kwth 750 kwth Thermal oil in/out 280/140 C 280/140 C 280/140 C Electricity output Gross 65 kwe 92 kwe 130 kwe Net (appr.) 51 kwe 81 kwe 114 kwe Condensor heat output 306 kwth 423 kwth 612 kwth Condensor circuit in/out 43/64 C 43/64 C 43/64 C Gross Electric Efficiency 17,3 % 17,7 % 17,3 % Net Electric Efficiency 13,6 % 15,6 % 15,2 %

12 23 24 ORC with double screw expander Heavy duty design, derived from screw compressors Not sensitive to fluid drops: can expand both superheated or saturated steam, no damage when fluids drops passes trough (usefull when large process variations are going on). As ORC usable at lower temperatures Adapted to recover jacket water heat Double srew expander based ORC ElectraTherm 3208 Goni Road Carson City, Nevada BEP EUROPE NV Ten Briele 6 B-8200 Brugge

13 25 3. ORC, fed by biomass combustion Many references in CH, A, D, I (also 1 in NL, 2 planned in Belgium). In concurrence with the steam cycle. Always designed as CHP. Turboden s.r.l. Viale Cernaia, Brescia - Italy 26

14 Turboden ORC-CHP range: MIROM Roeselare : 2,5 MWe net by Turboden Heat source: C 17 % net efficiency

15 ORC integration in an (existing) biomass boiler: Biomass boiler Greenhouse 4. ORC, fed by geothermal heat sources Many references known, from 250 kw to > 100 MW Source temperatures from 75 C up to 300 C. Same technology usable to recover waste heat on the same temperature levels.

16 31 Heber Geothermal 52 MWe power station (California) 32 Geothermal ORC 250 kwe (Ormat) Geothermal fluid temperature in/out: 110/85 C Thermal power in: ~ 2500 kw ORC working fluid: Isopentane

17 ORC derived from a centrifugal chiller (reversed) Cheap, reliable, proven technology 33 34

18 35 Pure Cycle 280: kwe net Power generation from thermal solar energy probably cheaper than photovoltaic solar systems possible to use condensor heat for sanitary heat water huge potential on desalination systems Evacuated tube collector fitted to temperatures untill C 40 kw solar heat ORC (Turboden, 1984)

19 Solar-biomass hybrid ORC 37 38

20 39 Principle design combined solar driven electricity and domnestic hot water production system (final work HOWEST, ) Tests (HOWEST) on a scroll expander (2005) (Sanden scroll car airco compressor TRS-090) 40

21 ORC driven domnestic micro-chp alternative to gas engine based micro CHP to integrate within a cv-boiler in concurrence with other new technologies as stirling engines, fuel cells Energetix Group plc Capenhurst Technology Park Chester CH1 6EH UK Genlec module: 1 kw scroll expander based ORC to integrate in central heating boilers (micro CHP) Example: Boiler manufacturor Daalderop (NL)

22 43 7. ORC driven cooling Alternative if electrical grid connection big chillers is impossible or not allowed. Been proven having better efficiency (COP) compared to absorption chillers. Solar powering or hybrid with solar heat feasible. Some Economics Some budget prices ORC-modules: 44 Turboden: 500kW: about 1900 /kwe 1000 kw: about 1350 /kwe 2000 kw: about 950 /KWe Pure Cycle 280 (ca 250 kwe) : or 1350/kWe Maxxtec/Adoratec: confidential prices, but of the same order of Turboden Also attractive priced new 60, 85 and 120 kw units. Tri-O-Gen: 150 kw ca 4300 /kwe (turn key?) BEP-Europe: 50 kw (module) or (installed) 2400 /kwe 4000 /kwe 250 kw unit: lower price/kwe compared with the 50 kwe unit

23 Some Economics 45 On renewable energy applications, we calculated a simple PBT of 3 year (IRR ca 25%), with the help of green certificates. For industrial waste heat recovery, a PBT of 5 year is realistic when available heat is on high temperature (~300 C). So the ROI can reach 15%, after taxes, what means that the investment can be asked within the benchmarking agreement. This result is strongly related to the electricity prices. Other financing methods (third party) could be considered - excellent CHP capability since the condensor heat can be used 46 Some Conclusions - ORC is a proven and commercially available technology for applications such as industrial waste heat recovery, ICE heat recovery, biomass burning, use of solar heat, geothermal heat sources - main advantage compared with a steam cycle is the higher thermal efficiency when using heat sources at lower temperatures. The ORC is also less complicated and easier to operate. Occuring pressures are lower. - the classical steam cycle should be considered when sufficient temperature levels are reachable (fuel burning) combined with turbine scale sizes from about 500 kwe to 2,5 MWe (to discuss, no clear answer given when to chose an ORC above a steam cycle) - favorable economical perspectives, especially in relation to green certificates or energy benchmarking.

24 2 master thesises Our ORC related activities TETRA project proposal on ORC in Technically and scientifically approved but not financed, had to be cancelled. New proposal in 2007, focused on renewable energy sources. Accepted, in progress from Oct 1st 2007 till Dec 31th 2009 Second proposal on industrial waste heat accepted (Jan 1st Dec 31 th 2011 or 2012). European ERA-SME concept with Ghent University and Stuttgart University of Applied Sciences as research partners. A TETRA project is 92,5 % financed by the Flemisch Government (IWT) and 7,5% by industrial partners (at least 4 SME s). 2 scientific researchers can work during 2 or 3 years on it. Cofinancing User Group is the preference partner to receive project information during project runtime, at the end publical available (by publications, seminars, website ) 2 th ORC Project structure 48

25 Laboratory setup For research and demonstrational purposes Laboratory setup Heat source: Maxxtec thermal oil heater Max C Flow: 14 m³/h 10 x 25kW, GC-Heat

26 Cooling loop: Laboratory setup 51 - water + glycol - max. 20m³/h - max. 120 C 3-way valve Cooler Circulator Flow sensor ing Bruno Vanslambrouck 52 Thanks for your attention. Questions??? HOWEST, dept Masters Industrial Sciences Laboratory of Industrial Physics and Applied Mechanics Graaf Karel de Goedelaan 5, B-8500 Kortijk Mail: bruno.vanslambrouck@howest.be Tel: or (dir)