Compressed-air-energy-storage (CAES) system and method

Patent metadata

Field	Value
Publication number	US-10584634-B2
Application number	US-201415104395-A
Country	US
Kind code	B2
Filing date	Dec 15, 2014
Priority date	Dec 16, 2013
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A compressed-air energy-storage system is described. The system includes a first compressor arrangement for compressing an air stream; a thermal energy storage unit, where through compressed air from the first compressor arrangement exchanges heat against a heat accumulation means; an air storage device arranged and configured for receiving and accumulating compressed air from the thermal energy storage unit; at least one expander for receiving compressed air from the air storage device and producing useful power therefrom. A further compressor arrangement is located between the thermal energy storage unit and the air storage device.

First claim

What is claimed is:

1. A compressed-air energy-storage system comprising:
a first compressor arrangement configured to compress an air stream, the first compressor arrangement comprising a plurality of compressor trains, each compressor train comprising a plurality of sequentially arranged compressors and a motor to drive the sequentially arranged compressors, wherein the motor of at least one of the plurality of compressor trains is a reversible electric motor operating as an electric generator when the system operates in an electric power generation mode;
a thermal energy storage configured to store thermal energy removed from the compressed air stream from the first compressor arrangement;
a second compressor arrangement configured to further compress the compressed air stream exiting the thermal storage energy storage unit, the second compressor arrangement comprising a compressor and a motor to drive the compressor, wherein the motor of the second compressor arrangement is separate and distinct from the respective motor of each of the plurality of compressor trains;
an air storage device configured to receive and accumulate the further compressed air stream from the second compressor arrangement; and
at least one expander configured to receive the further compressed air stream from the air storage device and produce useful power therefrom.

2. The system of claim 1 , wherein the air stream compressed by the first compressor arrangement has a pressure around 40-45 bar and a temperature around 600-680° C.

3. The system of claim 1 , wherein a compressed air delivery duct connects the air storage device to the at least one expander, the compressed air delivery duct being in heat exchange relation with the thermal energy storage unit such that compressed air from the air storage device receives heat from the energy storage device before entering the at least one expander.

4. The system of claim 1 , further comprising at least one clutch to mechanically connect the respective motor of at least one of the plurality of compressor trains selectively to the at least one expander and/or the respective compressor train driven by the motor.

5. The system of claim 1 , wherein a speed manipulation device is arranged between at least one of the plurality of compressor trains and the respective motor driving said compressor train.

6. The system of claim 1 , further comprising a variable frequency driver to control rotational speed of the motor of the second compressor arrangement.

7. The system of claim 1 , wherein each of the plurality of compressor trains comprises at least one speed manipulation device arranged between the relevant motor and a shaft line driving into rotation the compressors of the relevant compressor train.

8. The system of claim 1 , wherein the air storage device is positioned between the second compressor arrangement and the thermal energy storage unit.

9. The system of claim 8 , wherein the thermal energy storage unit is positioned between the air storage device and the expander.

10. The system of claim 9 , further comprising a delivery line fluidly coupling the air storage device to the thermal energy storage unit and configured to deliver the further compressed air stored in the air storage device to the thermal energy storage unit before said further compressed air enters the expander.

11. The method of claim 10 , wherein one fluid path of the thermal energy storage unit is between the first compressor arrangement and the second compressor arrangement and another fluid path of the energy storage device is between the air storage device and the expander.

12. The system of claim 11 , wherein a safety cooler is arranged between the second compressor arrangement and the air storage device.

13. The system of claim 1 , wherein no intercooler is provided between the sequentially arranged compressors of each of the plurality of compressor trains.

14. A method for operating a compressed-air energy-storage system comprising:
compressing a flow of air with a first compressor arrangement at a first pressure, the first compressor arrangement comprising a plurality of compressor trains, each compressor train comprising a plurality of sequentially arranged compressors driven by a motor, wherein the motor of at least one of the plurality of compressor trains is a reversible electric motor operating as an electric generator when the system operates in an electric power generation mode;
flowing the compressed air at the first pressure through a thermal energy storage unit for removing heat from the compressed air and storing thermal energy in the thermal energy storage unit;
further compressing the compressed air from the thermal energy storage unit at a second pressure using a second compressor arrangement, the second compressor arrangement comprising a compressor driven by a motor separate and distinct from the respective motor of each of the plurality of compressor trains, and delivering the further compressed air to an air storage device; and
storing the further compressed air in the air storage device.

15. The method of claim 14 , further comprising:
delivering compressed air from the air storage device to the thermal energy storage unit;
heating the compressed air with thermal energy from the thermal energy storage unit; and
expanding the heated compressed air in at least one expander and producing useful energy therefrom.

16. The system of claim 14 , wherein no intercooler is provided between the sequentially arranged compressors of each of the plurality of compressor trains.

17. A compressed-air energy-storage system comprising:
a first compressor arrangement configured to compress an air stream, the first compressor arrangement comprising a plurality of compressor trains, each compressor train comprising a plurality of sequentially arranged compressors and a motor to drive the sequentially arranged compressors, wherein the motor of at least one of the plurality of compressor trains is a reversible electric motor operating as an electric generator when the system operates in an electric power generation mode;
a thermal energy storage unit configured to receive the first compressed air stream from the first compressor arrangement, the thermal energy storage unit having a thermal energy storage medium configured to store thermal energy from the first compressed air stream;
a second compressor arrangement configured to receive the first compressed air stream from the thermal energy storage unit and compress the first compressed air stream into a second compressed air stream, the second compressor arrangement comprising a compressor driven by a second motor separate and distinct from the respective motor of each of the plurality of compressor trains;
a variable frequency driver to control rotational speed of the motor of the second compressor arrangement;
an air storage device positioned between the second compressor arrangement and the thermal energy storage unit and configured to receive and accumulate the second compressed air from the second compressor arrangement;
at least one expander configured to receive the second compressed air stream from the air storage device and to produce power therefrom; and
a compressed air delivery duct fluidly connecting the air storage device to the at least one expander, the compressed air delivery duct passing through the thermal energy storage unit in heat exchange relation with the thermal energy storage unit before entering the expander, such that the second compressed air from the air storage device receives heat from the the

Assignees

• Nuovo Pignone Srl

Inventors

• Kosamana Bhaskara
• Venkatachalam Kalyan Kumar

Classifications

• H02K7/1823

  structurally associated with turbines or similar engines · CPC title

• F02C7/143

  before or between the compressor stages · CPC title

• F02C6/16 Primary

  for storing compressed air · CPC title

• F05D2220/32

  in gas turbines · CPC title

• F05D2220/76

  an electrical generator · CPC title