THERMOELECTRIC ENERGY STORAGE SYSTEM HAVING AN INTERNAL HEAT EXCHANGER AND METHOD FOR STORING THERMOELECTRIC ENERGY

• US 20120222423A1
• Filed: 04/11/2012
• Published: 09/06/2012
• Est. Priority Date: 10/13/2009
• Status: Abandoned Application

• Current Assignee: ABB Research Ltd. (ABB Limited)
• Original Assignee: ABB Research Ltd. (ABB Limited)
• Inventors: Hemrle, Jaroslav, Kaufmann, Lilian, MERCANGOEZ, Mehmet
• Application Number:
  US13/444,451
• Publication Number:
  US 20120222423A1
• Time in Patent Office: Days
• US Class Current: 60/645
• CPC Class Codes: F01K 11/04 the boilers or condensers being rotated in use
• CPC Class Codes: F01K 3/006 Accumulators and steam compressors
• CPC Class Codes: F01K 3/12 having two or more accumulators

Abstract

Exemplary embodiments are directed to a thermoelectric energy storage system (TEES) and method for converting electrical energy into thermal energy to be stored and converted back to electrical energy with an improved round-trip efficiency are disclosed. The TEES includes a working fluid circuit for circulating a working fluid through a first heat exchanger and a second heat exchanger, a thermal storage medium circuit for circulating a thermal storage medium, the thermal storage medium circuit having at least one hot storage tank coupled to a cold storage tank via the first heat exchanger. The arrangement maximizes the work performed by the cycle during charging and discharging for a given maximum pressure and maximum temperature of the working fluid.

Claims

1. A thermoelectric energy storage system having a charging cycle for providing thermal energy to a thermal storage, and a discharging cycle for generating electricity by retrieving the thermal energy from the thermal storage, the thermoelectric energy storage system comprising:

a working fluid circuit for circulating a working fluid through a first heat exchanger and a second heat exchanger; and

a thermal storage medium circuit for circulating a thermal storage medium, the thermal storage medium circuit having at least one hot storage tank coupled to a cold storage tank via the first heat exchanger,

wherein, the second heat exchanger is adapted to cool the working fluid at an output of the first heat exchanger during a charging cycle, and adapted to pre-heat the working fluid at an input to the first heat exchanger during a discharging cycle.

2. The system according to claim 1, wherein, during the charging cycle, the second heat exchanger comprises:

a first input from the first heat exchanger connected to a first output leading to an expander; and

a second input from a condenser connected to a second output leading to a compressor.

3. The system according to claim 1, wherein, during the discharging cycle, the second heat exchanger comprises;

a first input from a pump connected to a first output leading to the first heat exchanger; and

a second input from a thermodynamic machine connected to a second output leading to a condenser.

4. The system according to claim 1, wherein at least one section of a charging cycle or a discharging cycle runs transcritically.

5. The system according to claim 1, wherein either the charging cycle or the discharging cycle runs without the second heat exchanger.

6. The system according to claim 2, wherein at least one section of a charging cycle or a discharging cycle runs transcritically.

7. The system according to claim 2, wherein either the charging cycle or the discharging cycle runs without the second heat exchanger.

8. The system according to claim 3, wherein at least one section of a charging cycle or a discharging cycle runs transcritically.

9. The system according to claim 3, wherein either the charging cycle or the discharging cycle runs without the second heat exchanger.

11. The method according to claim 6, wherein the step of cooling the working fluid output from the first heat exchanger during charging, comprises:

transferring heat from the working fluid exiting the first heat exchanger to the working fluid output from an evaporator.

12. The method according to claim 6, wherein the step of pre-heating the working fluid input into the first heat exchanger during discharging, further comprises:

transferring heat from the working fluid exiting a thermodynamic machine to the working fluid input into the first heat exchanger.

15. The method according to claim 11, wherein at least one section of a charging cycle or a discharging cycle is performed transcritically.

16. The method according to claim 11, comprising:

running either the charging cycle or the discharging cycle runs without the second heat exchanger.

17. The method according to claim 12, wherein at least one section of a charging cycle or a discharging cycle is performed transcritically.

18. The method according to claim 12, comprising:

running either the charging cycle or the discharging cycle runs without the second heat exchanger.

10. A method for storing and retrieving energy in a thermoelectric energy storage system, comprising:

charging the system by heating a thermal storage medium, wherein the thermal storage medium circulates between at least one hot storage tank and a cold storage tank;

discharging the system by heating a working fluid in a working fluid circuit with heat from the thermal storage medium and expanding the working fluid through a thermodynamic machine;

cooling the working fluid output from a first heat exchanger during charging by means of a second heat exchanger; and

pre-heating the working fluid input into the first heat exchanger during discharging by means of a second heat exchanger.

13. The method according to claim 10, wherein at least one section of a charging cycle or a discharging cycle is performed transcritically.

14. The method according to claim 10, comprising:

running either the charging cycle or the discharging cycle runs without the second heat exchanger.