The Hybrid tri- genera0on system solar- bio- tric

Transcription

1 The Hybrid tri- genera0on system solar- bio- tric S. Karellas and K. Braimakis Na0onal Technical University of Athens 1 st Solar Open Workshop Building Integrated Solar Energy Technologies Athens, Greece September 5 th, 2015

2 Contents 1. The hybrid tri/cogenera#on concept in residen#al sector - Advantages - Overview of systems 2. Thermodynamic analysis - ORC- VCC system - PV- heat pump system 3. Economic assessment - Hea0ng/cooling loads - Sizing and opera0on strategy - Economic evalua0on 4. Conclusions 5. Overview of Bio- TRIC unit 2

3 1. The hybrid tri/cogenera#on concept in residen#al sector - Advantages Solar power Electricity TRI- CO- GENERATION SYSTEM Cooling Biomass Hea0ng CO 2 - free renewable sources Poten0ally lisle or no fuel cost Fossil fuel independent Possible opera0on in off- grid areas Especially interes0ng for areas with ample biomass and solar radia0on 3

4 1. The hybrid tri/cogenera#on concept in residen#al sector - Overview of systems ORC- VCC ORC- VCC 4

5 1. The hybrid tri/cogenera#on concept in residen#al sector - Overview of systems ORC- VCC Bio Solar Boiler PTC ORC- VCC Condenser Hea0ng 5

6 1. The hybrid tri/cogenera#on concept in residen#al sector - Overview of systems ORC- VCC Bio Solar Boiler PTC ORC- VCC ORC Expander Electricity Condenser Hea0ng 6

7 1. The hybrid tri/cogenera#on concept in residen#al sector - Overview of systems ORC- VCC Bio Solar Boiler PTC ORC- VCC ORC Expander Electricity Condenser Hea0ng VCC evaporator Cooling 7

8 1. The hybrid tri/cogenera#on concept in residen#al sector - Overview of systems ORC- VCC PV heat pump Bio Solar Boiler PTC ORC- VCC Condenser ORC Expander Electricity VCC Hea0ng VCC evaporator Cooling 8

9 1. The hybrid tri/cogenera#on concept in residen#al sector - Overview of systems ORC- VCC PV heat pump Bio Solar Solar Boiler PTC PV ORC- VCC Condenser ORC Expander Electricity VCC Electricity Hea0ng VCC evaporator Cooling 9

10 1. The hybrid tri/cogenera#on concept in residen#al sector - Overview of systems ORC- VCC PV heat pump Bio Solar Solar Boiler PTC PV ORC- VCC Condenser ORC Expander Electricity VCC Electricity VCC evaporator Hea0ng Cooling VCC evaporator Cooling VCC condenser Hea0ng Both systems are grid- connected 10

11 Laboratory of Steam Boilers and Thermal Plants Assist. Prof. So:rios Karellas The hybrid power based tri/cogenera#on concept- ORC and VCC integra:on Organic Rankine Cycle for Power Genera0on Q in P el Q out S 11

12 Laboratory of Steam Boilers and Thermal Plants Assist. Prof. So:rios Karellas The hybrid power based tri/cogenera#on concept- ORC and VCC integra:on Organic Rankine Cycle for Power Genera0on 12

13 Laboratory of Steam Boilers and Thermal Plants Assist. Prof. So:rios Karellas The hybrid power based tri/cogenera#on concept- ORC and VCC integra:on Vapor Compression Cycle for Cooling Q out P el Q in 13

14 Laboratory of Steam Boilers and Thermal Plants Assist. Prof. So:rios Karellas The hybrid power based tri/cogenera#on concept- ORC and VCC integra:on Vapor Compression Cycle for Cooling 14

15 Laboratory of Steam Boilers and Thermal Plants Assist. Prof. So:rios Karellas The hybrid power based tri/cogenera#on concept- ORC and VCC integra:on Organic Rankine Cycle for Power Genera0on Vapor Compression Cycle for Cooling Q in Q out P el Q out P el Q in 15

16 2. Thermodynamic analysis - ORC- VCC system Heating load Electricity G M Heating load Biomass and PTC hot water circuits provide heat to the ORC and hea0ng load Common ORC- VCC condenser Two modes of opera0on: Trigenera0on (ORC- VCC) Cogenera0on (ORC) ORC Cooling load VCC Heating load 16

17 2. Thermodynamic analysis 17

18 2. Thermodynamic analysis - ORC- VCC system Working fluid: R227ea (Pcrit=29.25bar, Tcrit= C ) Opera0ng pressure (supercri0cal) : 30.4 bar Expander inlet temperature : 110 C Condensa0on at 50 o C and 9.2 bar VCC evapora0on at 7 o C and 2.5 bar Isentropic efficiencies: Pump: 65 % Expander: 60 % Compressor: 75 % PTC efficiency parameters η 0 =0.70 a 1 = a 2 = Boiler efficiency: 83 % 18

19 2. Thermodynamic analysis - PV- heat pump system PV module produces electricity Cooling and hea0ng produced by the VCC 19

20 2. Thermodynamic analysis - PV- heat pump system Working fluid: R227ea (Pcrit=29.25bar, Tcrit= C ) Condensa0on at 50 o C and 9.2 bar VCC evapora0on at 7 o C and 2.5 bar Isentropic efficiencies: Compressor: 75 % PV panels HIT (Heterojunc0on with Intrinsic Thin layer) Module efficiency (STC): 19 % (linear dependence to irradiance) Power output (STC): 190 W/m 2 (240 W/module) System has one central inverter with MPP trackers Inverter efficiency: 95 % Connec0on- to- grid losses: 2 % 20

21 3. Economic assessment - Hea0ng/cooling loads 3 floor typical apartment block 2 x 105 m 2 appartments / floor 4 persons/appartment Total : 6 appartments (630 m 2 ) /24 inhabitants Complete exterior insula0on, double- glazing windows and doors of low heat transfer coefficient à Um= (W/m 2 K) Space and water hea0ng as well as cooling requirements in accordance with Greek legisla0on standards Distribu0on and terminal units efficiency: 80% All clima0c condi0ons retrieved for Heraklion, Crete 21

22 3. Economic assessment - Hea0ng/cooling loads Thermal - cooling energy (kwh) per month Cooling load (kwhth) Space hea0ng load (kwhth) Hea0ng load for DHW (kwh) Month 22

23 3. Economic assessment - Sizing and opera0on strategy Solar/Biomass ORC VCC system : q DNI>0, ORC ONLINE ü ORC opera0on primarily follows hea0ng load, par0al load 80 % of nominal load ü If Q PTC > heat required by working fluidà heat is stored. ü If Q PTC < heat required by working fluidà biomass boiler contributes to the heat input v if Qcond > Qh,load à heat is stored v if Qcond < Qh,load à biomass boiler provides addi0onal heat q DNI=0, ORC OFFLINE ü If stored energy (from PTC and condenser) is not adequate à biomass boiler contributes to cover hea0ng load q VCC follows cooling load during the summer PV- heat pump system: Heat pump primarily follows heat and cooling load 23

24 3. Economic assessment - Sizing and opera0on strategy Solar/Biomass ORC VCC system ORC: 50 % of the maximum hea0ng load VCC: 100 % of the maximum cooling load PTC: 21 m 2 PV- Heat pump PV : maximum capacity VCC: 100 % of hea0ng load allowed by Greek legisla0on for roofs of residen0al buildings 10 kw e à A=55.48m 2 ORC- VCC PV- heat pump Q bio,nom 12 kw th P el,pv,nom 10 kw e Q sol,nom 8 kw th P el,pv kw e P el,net,nom 0.2 kw el Q h,nom kw th Q h,nom 5.16 kw th Q c,nom 7.65 kw th Q c,nom 4 kw th COP c 3.38 COP c 3.38 COP h η el 2.40 % η el,pv % η CHP % 24

25 3. Economic assessment - Economic evalua0on Both systems are economically assessed against a conven0onal hea0ng- cooling system (oil- fired boiler for hea0ng and air condi0oning system for cooling) Economic benefits: cost avoided for the hea;ng /cooling produced by the conven;onal systems Produced electricity sold to the grid Main costs include Capital cost Maintenance and opera;on cost 25

26 3. Economic assessment - Economic evalua0on ORC- VCC system PV- heat pump system Woodchips boiler (12 kw th ) PTC (21 m 2 ) ORC module (0.2 kw e ) VCC (kw th ) 300 /kw th 400 /m /kw e 500 /kw th PV panels Inverter (10 kw e ) Heat pump Fan coils 2130 /kw e /kw th 250 /unit Fuel and electricity costs Electricity (from grid) Home hea#ng oil Biomass fuel Electricity selling price (to grid) ORC- VCC system PV- heat pump system /kwh e /kwh th 200 /tn 200 /MWh e 115 /MWh e Price for small biomass plants Feed- in tariff 26 26

27 3. Economic assessment - Economic evalua0on 100% 100% 90% VCC: % Fan coil units: 3000 % of Total Investment Cost 80% 70% 60% 50% 40% 30% 20% 10% ORC module: 2000 PTC (21 m 2 ): 8000 Woodchips boiler: % 70% 60% 50% 40% 30% 20% 10% Heat pump: 2000 Inverter: 2600 PV panels: % 0% Total=18720 Total=28900 ü solar conversion modules: most expensive component (43% of TCI in ORC- VCC and 73% in PV- HP) 27

28 3. Economic assessment - Economic evalua0on Cooling 7% Electricity 2% Biomass Electricity Maintenance 20% 91% 14% 66% Hea#ng Annual Income (4419 ) Net annual income: 2505 Annual Costs (1914 )

29 3. Economic assessment - Economic evalua0on Cooling 5% Electricity 25% Electricity Maintenance 22% 78% 70% Hea#ng Annual Income (5772 ) Net annual income: 3136 Annual Costs (2636 ) ü Important saving: replacement of oil fired boiler ü ORC- VCC : lower capital cost, lower net annual income ü PV- HP : 54 % higher capital cost, higher net annual income (25 % greater) 29

30 3. Economic assessment - Economic evalua0on Project life 20 years ORC- VCC NPV ( ) 1890 PV- heat pump Interest rate DBP (years) % ORC- VCC IRR (%) 9 PV- heat pump 0 ORC- VCC For net metering scheme: NPV =3665, IRR= 10%, DBP= years ü Both systems : profitable PV- heat pump 30

31 4. Conclusions Two different (trigenera0on) hea0ng and cooling systems, have been simulated and economically evaluated. A typical apartment block located in Crete, Greece was considered and it was the basis for the calcula0on of the hea0ng/cooling loads. ORC- VCC : beser economic performance due to lower capital cost despite the lower net annual income due to low electric efficiency (2.5%) PV- HP : The higher net annual income does not compensate for the higher capital cost The tri/cogenera0on systems presented were found cost compe00ve against the conven0onal cooling and oil hea0ng technologies. Results strongly dependent on electricity selling price of technologies 31

32 5. Overview of Bio- TRIC unit Scroll expander coupled with generator Close- up of scroll expander 32

33 5. Overview of Bio- TRIC unit Configura0on of scroll compressor and expanders coupled with generators in experimental rig 33

34 5. Overview of Bio- TRIC unit Diaphragm feed pump used in the ORC circuit 34

35 Na#onal Technical University of Athens Laboratory of Steam Boilers and Thermal Plants Assoc. Prof. So:rios Karellas 5. Overview of Bio- TRIC unit S u p e r c r i 0 c a l heater VCC (small) condenser Common (large) condenser 35

36 Thank you for your afen#on! Heating load Heating load Electricity G M ORC Cooling load VCC Acknowledgements Heating load Bio- TRIC project funded by na0onal funding program ARISTEIA II of the General Secretariat of Research and Technology, Greece 36