Integration of the CHEST-System for Power-to-Heat to-power storage in Smart District Heating IRES 2017 Henning Jockenhöfer Dan Bauer

Transcription

1 DLR.de Slide 1 Integration of the CHEST-System for Power-to-Heat to-power storage in Smart District Heating IRES 2017 Henning Jockenhöfer Dan Bauer

2 DLR.de Slide 2 Motivation? Electrical energy generated from wind and PV not dispatchable High share of renewable energy sources require storages Potential for pumped-hydro energy storages geologically limited Power-to-Heat-to-Power storage systems are a promising alternative

3 DLR.de Slide 3 Power-to-Heat-to-Power (PHP) based on resistance heating thermal energy storage (TES) wind/pv P el,charge G P el,discharge Ideal efficiency: Carnot-factor of heat engine Real efficiency: ~35-40 %

4 DLR.de Slide 4 PHP based on Pumped Thermal Energy Storage (PTES) charge discharge wind/pv thermal energy storage (TES) T P el,charge heat pump heat engine P el,discharge T heat source heat sink s s Ideal cycle: roundtrip efficiency = 100 %

5 DLR.de Slide 5 Compressed Heat Energy STorage (CHEST) PTES based on subcritical Rankine-cycle charge hot storage M P el,charge T cold reservoir hot storage P el,discharge discharge G cold reservoir s

6 DLR.de Slide 6 Exergy losses in real CHEST systems Temperature differences during heat transfer Isentropic efficiency of compressor and turbine T storage temperature charged energy discharged energy exergy losses design of thermal energy storage is crucial s

7 DLR.de Slide 7 Compensation of exergy losses by separation of heat source and sink T charged energy discharged energy T source T sink s Suitable heat source?

8 DLR.de Slide 8 Smart District Heating (SDH) renewable heat sources district heating solar thermal biomass seasonal pit water storage ~ m³

9 DLR.de Slide 9 Smart District Heating (SDH) renewable heat sources district heating solar thermal biomass pit water storage solar field seasonal pit water storage ~ m³ Source: Marstal District Heating

10 DLR.de Slide 10 Sector coupling of the CHEST concept with SDH wind power charge discharge consumer M thermal energy storage G environment /seawater solar field Seasonal pit water storage ~ m³ district heating

11 DLR.de Slide 11 Organic Rankine-cycle (ORC) based CHEST Detailed numerical investigation of the CHEST system Consideration of parasitics, pressure losses and isentropic machinery efficiencies

12 DLR.de Slide 12 Parameter study of ORC-CHEST Mode 1: Maximum power ratio No reuse of condenser heat power ratio = P el,discharge P el,charge Mode 2: Medium power ratio Reuse of condenser heat Mode 3: Medium power ratio No reuse of condenser heat

13 DLR.de Slide 13 Sector coupling of the CHEST concept with SDH Mode 1: power ratio = 1.25, T source =100 C, T sink = 15 C wind power charge discharge consumer 1 MW el MW el. M thermal energy storage G 8.1 MW th. 15 C 7.7 MW th. environment /seawater 100 C 95 C solar field 90 C 40 C district heating

14 DLR.de Slide 14 Sector coupling of the CHEST concept with SDH Mode 2: power ratio = 0.8, T source =100 C, T sink = 50 C wind power charge discharge consumer 1 MW el. 0.8 MW el. M thermal energy storage G 6.7 MW th. 100 C 95 C 6.8 MW th. 90 C solar field 40 C 50 C district heating

15 DLR.de Slide 15 Sector coupling of the CHEST concept with SDH Mode 3: power ratio = 1.0, T source =90 C, T sink = 15 C wind power charge discharge consumer 1 MW el. 1 MW el. M thermal energy storage M 6.2 MW th. 90 C 15 C 6.1 MW th. environment /seawater 85 C 90 C solar field 40 C district heating

16 DLR.de Slide 16 Sector coupling of the CHEST concept with SDH Heat pump mode: power ratio = 0, T source =30 C, T sink = 80 C wind power charge discharge consumer M thermal energy storage M 80 C solar field 30 C district heating

17 DLR.de Slide 17 Conclusion and outlook Conclusions Detailed Simulation of a CHEST-system was conducted. Flexible system operation in combination with Smart District Heating is possible. High electrical power ratio is attainable. Condenser and evaporator outlet heat is reusable in district heating. Development of suitable key components (compressor, latent heat storage) is necessary. Outlook System simulations with detailed modeling of SDH Investigation of stand-alone water-steam CHEST for multi-mw scale without low temperature heat integration

18 DLR.de Slide 18 Thank you for your attention!