Cogeneration at a small District Heating Network. IDEA 101 st Annual Conference Indianapolis June

Transcription

1 Cogeneration at a small District Heating Network IDEA 101 st Annual Conference Indianapolis June

2 This is what I m going to tell you Introduction Situation for district heating in Sweden Why cogeneration? Example from Älvsbyn and Vetlanda in Sweden Typical P&I for small Swedish plants Conclusion 2

3 Sweden in the World 1000 miles long x 250 miles wide SWEDEN 3

4 Sweden Älvsbyn 8500 cit. Vetlanda cit. 4

5 District Heating in Sweden Losses Housing and services Industry Source: Energimyndigheten 5

6 Fuel for DH and cogeneration production in Sweden 2008 Misc 2% Heat pumps (elec.+heat) 9% Peat 5% Electricity 3% Fossil fuel 9% Industrial waste heat 7% Waste 15% Land fill gas 2% Bio mass fuel 48% Source : Svensk Fjärrvärme 6

7 Why cogeneration from a Swedish point of view? The fuel on top, typically oil, has become expensive Existing hot water boilers for biomass fuel are old and obsolete, decreasing availability The government has stimulated new renewable electricity production. Green certificate! The price of electricity has increased 7

8 CHP plant Älvsbyn Sweden 8

9 Älvsbyn in winter -31 F 9

10 Automatic fuel handling 10

11 Fuel crane Älvsbyn 11

12 Interior CHP Älvsbyn 12

13 Data Älvsbyn CHP built 2007 CHP bolier 14 MWth from KMW Energi Flue gas condenser 3 MW (cover 20% of DH) Turbine 3 MW Heat power to grid 14 MW DH production 73 GWh/y Power production 11 GWh/y Investment 16 million $ Income from power production 1 million $ /y 13

14 Vetlanda CHP Plant 14

15 DH network in Vetlanda 15

16 Vetlanda, before flue gas condenser 30 30,0 25,0 Oil boilers 30 MW Production 138 GWh, Fuel cost 4,6 million $ 20,0 15,0 Boiler 1 biomass 6 MW MW heat 10,0 5,0 0 0,0-5,0-10,0 Boiler 2 biomass 11 MW Boiler 3 biomass 4MW Landfill Biogas 0,4 MW Days

17 Vetlanda, today with FGC 30 30,0 25,0 Oil boilers 30 MW Production 138 GWh dh, Fuel cost 3,7 million $ Fuel cost reduction 0,9 million $/y MW heat 20,0 15,0 10,0 Boiler 1 biomass 6 MW Boiler 2 biomass 11 MW Flue gas condenser NO FUEL COST 5,0 0 0,0-5,0-10,0 Boiler 3 biomass 4 MW Landfill Biogas 0,4 MW Days

18 MW electricity & heat 30,0 25,0 20,0 15,0 10,0 5,0 0 0,0 5-5, ,0 Boiler 2+ fgc Vetlanda, future Oil CHP 25 MW boiler Electricity 5 MW Boiler 3 Production 138 GWh dh, 26 GWh el Fuel cost 3,9 million $ Days CHP, flue gas condenser Land fill Biogas Boiler 2+ fgc

19 MW electricity & heat 30 30,0 25,0 20,0 15,0 10,0 5,0 Oil Vetlanda, future (month by month) CHP 25 MW Production 138 GWh dh, 26 GWh el Fuel cost 3,9 million $ CHP, flue gas condensor Boiler 2 +fgc Boiler ,0-5, Electricity 5 MW Land fill Biogas 0,4 MW 10-10,0 19

20 Vetlanda Sold heat 118 GWh/y Electricity production 26 GWh/y Income from sold energy 12 million $/y Heat 9 millon $/y Electricity 3 million $/y Fuel cost 4 millon $/y Investment 33 million $ 20

21 Typical P&I for a CHP plant Turbine Generator Fuel Boiler Flue gas filter Flue gas cond Condensor Accumulator Feed Water Cleaning

22 The DH grid Accumulator DH grid Design temp 120º C Design pressure 16 bar g 42º C DH Pump Difference pressure transmitter To Customers º C Top Boiler

23 The DH Acummulator Turbine Condenser Flue gas Condenser 70-98º C 42º C DH Accumulator DH Network

24 The turbine cycle Steam Generator To Grid Turbine Fuel Boil er Flue Gas Filter Flue Gas Condenser 50º C Turbine Condensor Accumulator Bottom Ash Feed Water Feed Water Pump

25 The flue gas system Dry stack for bypass 160º C Flue gas filter ID Fan Wet stack 45º C Flue gas condenser 50º C 42º C To Turbine Condenser From Accumulator = grid Fly Ash To flue gas condensate cleaning

26 The flue gas condensate system Flue gas condenser Filters for water cleaning Flue Gas condensate To storm water drain or to make up water

27 Conclusion Keep temperatures in the grid low (better alfa) Don t over estimate the heat demand Pay attention to part load performance Pay attention to heat losses in the grid If the fuel is cheap enough build radiators for cooling (more full load) Use flue gas condenser (low return temp is important) Power production decrease the DH price 27