Systems and Methods for Energy Storage and Recovery Using Compressed Gas

• US 20090282822A1
• Filed: 04/09/2009
• Published: 11/19/2009
• Est. Priority Date: 04/09/2008
• Status: Active Grant

• Current Assignee: SustainX, Inc. (General Compression, Inc.)
• Original Assignee: SustainX, Inc. (General Compression, Inc.)
• Inventors: McBride, Troy O., Bollinger, Benjamin R.
• Granted Patent: US 7,832,207 B2
• Time in Patent Office: Days
• US Class Current: 60/415
• CPC Class Codes: F15B 1/024 used as a supplementary power source, e.g. to store energy in idle periods to balance pump load
• CPC Class Codes: F15B 11/032 by means of fluid-pressure converters
• CPC Class Codes: F15B 21/08 Servomotor systems incorporating electrically operated control means F15B21/02, F15B21/065 take precedence
• CPC Class Codes: F15B 2211/20569 capable of working as pump and motor
• CPC Class Codes: F15B 2211/212 the pressure sources being accumulators
• CPC Class Codes: F15B 2211/214 the pressure sources being hydrotransformers
• CPC Class Codes: F15B 2211/216 the pressure sources being pneumatic-to-hydraulic converters
• CPC Class Codes: F15B 2211/30505 Non-return valves, i.e. check valves
• CPC Class Codes: F15B 2211/3057 having two valves, one for each port of a double-acting output member
• CPC Class Codes: F15B 2211/30575 in a Wheatstone Bridge arrangement (also half bridges)
• CPC Class Codes: F15B 2211/3058 having additional valves for interconnecting the fluid chambers of a double-acting actuator, e.g. for regeneration mode or for floating mode directional control valves having a regenerative position F15B2211/3133; directional control valves having a floating position F15B2211/3127
• CPC Class Codes: F15B 2211/3111 the pump port being closed in the centre position, e.g. so-called closed centre
• CPC Class Codes: F15B 2211/31594 having multiple pressure sources and multiple output members
• CPC Class Codes: F15B 2211/327 electrically or electronically
• CPC Class Codes: F15B 2211/40515 with variable throttles or orifices
• CPC Class Codes: F15B 2211/41509 being connected to a pressure source and a directional control valve
• CPC Class Codes: F15B 2211/41554 being connected to a return line and a directional control valve
• CPC Class Codes: F15B 2211/426 electrically or electronically
• CPC Class Codes: F15B 2211/45 Control of bleed-off flow, e.g. control of bypass flow to the return line
• CPC Class Codes: F15B 2211/50581 using counterbalance valves
• CPC Class Codes: F15B 2211/5153 : being connected to an output member and a directional control valve
• CPC Class Codes: F15B 2211/62 : Cooling or heating means
• CPC Class Codes: F15B 2211/6309 : the pressure being a pressure source supply pressure
• CPC Class Codes: F15B 2211/7058 : Rotary output members

Abstract

The invention relates to methods and systems for the storage and recovery of energy using open-air hydraulic-pneumatic accumulator and intensifier arrangements that combine at least one accumulator and at least one intensifier in communication with a high-pressure gas storage reservoir on a gas-side of the circuits and a combination fluid motor/pump, coupled to a combination electric generator/motor on the fluid side of the circuits.

Claims

1. A compressed gas-based energy storage system comprising a staged hydraulic-pneumatic energy conversion system comprising:

a compressed gas storage system;

an accumulator having a hydraulic side and a pneumatic side separated by an accumulator boundary mechanism, the accumulator being configured to transfer mechanical energy from the pneumatic side to the hydraulic side at a first pressure ratio;

an intensifier having a hydraulic side and a pneumatic side separated by an intensifier boundary mechanism, the intensifier being configured to transfer mechanical energy from the pneumatic side to the hydraulic side at a second pressure ratio greater than the first pressure ratio; and

a control system for operating the compressed gas storage system, the accumulator, the intensifier in a staged manner to provide a predetermined pressure profile at at least one outlet.

2. The compressed gas-based energy storage system of claim 1, further comprising a control valve arrangement, responsive to the control system, for interconnecting the compressed gas storage system, the accumulator, the intensifier, and the at least one outlet.

3. The compressed gas-based energy storage system of claim 1, wherein the control valve arrangement comprises:

a first arrangement providing controllable fluid communication between the accumulator pneumatic side and the compressed gas storage system;

a second arrangement providing controllable fluid communication between the accumulator pneumatic side and the intensifier pneumatic side;

a third arrangement providing controllable fluid communication between the accumulator hydraulic side and the at least one outlet; and

a fourth arrangement providing controllable fluid communication between the intensifier hydraulic side and the at least one outlet.

4. The compressed gas-based energy storage system of claim 1, wherein the staged hydraulic-pneumatic energy conversion system further comprises a second intensifier having a hydraulic side and a pneumatic side separated by a second intensifier boundary mechanism, the second intensifier being configured to transfer mechanical energy from the pneumatic side to the hydraulic side at a third pressure ratio greater than the second pressure ratio.

5. The compressed gas-based energy storage system of claim 1, wherein the staged hydraulic-pneumatic energy conversion system further comprises a second accumulator having a hydraulic side and a pneumatic side separated by a second accumulator boundary mechanism, the accumulator being configured to transfer mechanical energy from the pneumatic side to the hydraulic side at the first pressure ratio, wherein the second accumulator is connected in parallel with the first accumulator.

6. The compressed gas-based energy storage system of claim 1, wherein the staged hydraulic-pneumatic energy conversion system further comprises a hydraulic motor/pump having an input side in fluid communication with the at least one outlet and having an output side in fluid communication with at least one inlet in fluid communication with the control valve arrangement.

7. The compressed gas-based energy storage system of claim 1, wherein the staged hydraulic-pneumatic energy conversion system further comprises an electric generator/motor mechanically coupled to the hydraulic motor/pump.

8. The compressed gas-based energy storage system of claim 1, wherein the control system comprises a sensor system that monitors at least one of (a) a fluid state related to the accumulator pneumatic side, the intensifier pneumatic side, the accumulator hydraulic side and the intensifier hydraulic side (b) a flow in hydraulic fluid, or (c) a position of the accumulator boundary mechanism and intensifier boundary mechanism.

9. The compressed gas-based energy storage system of claim 1, wherein the control valve arrangement allows gas from the compressed gas storage system to expand first within the accumulator pneumatic side and then from the accumulator pneumatic side into the intensifier pneumatic side in a staged manner.

10. The compressed gas-based energy storage system of claim 9, wherein the gas expansion occurs substantially isothermally.

12. The compressed-gas based energy storage system of claim 10, wherein the system is configured to provide substantially isothermal gas expansion via heat transfer from outside the accumulator and the intensifier therethrough, and to the gas within the accumulator pneumatic side and the intensifier pneumatic side.

13. The compressed-gas based energy storage system of claim 1, wherein the compressed gas storage system comprises at least one pressurized gas vessel.

14. The compressed gas-based energy storage system of claim 6, wherein the control system opens and closes each of the control valve arrangements so that, when gas expands in the accumulator pneumatic side, the intensifier pneumatic side is vented by the gas vent to low pressure whereby fluid is driven from the accumulator hydraulic side by the expanding gas through the motor/pump, and into the intensifier hydraulic side.

15. The compressed gas-based energy storage system of claim 6, wherein the control system opens and closes each of the control valve arrangements so that, when gas expands in the intensifier pneumatic side, fluid is driven from the intensifier hydraulic side by the expanding gas through the motor/pump, and into the accumulator hydraulic side and the accumulator pneumatic side is in fluid communication with the intensifier pneumatic side.

11. (canceled)

16. A compressed gas-based energy storage system comprising a staged hydraulic-pneumatic energy conversion system comprising:

a compressed gas storage system;

at least one accumulator having an accumulator pneumatic side and an accumulator hydraulic side, the accumulator pneumatic side and the accumulator hydraulic side being separated by an accumulator boundary mechanism that transfers mechanical energy therebetween, wherein the accumulator pneumatic side is in fluid communication with the compressed gas storage system via a first control valve arrangement;

at least one intensifier having an intensifier pneumatic side and an intensifier hydraulic side, the intensifier pneumatic side and the intensifier hydraulic side being separated by an intensifier boundary mechanism that transfers mechanical energy therebetween, wherein the intensifier pneumatic side is in fluid communication with the accumulator pneumatic side and a gas vent via a second control valve arrangement;

a hydraulic motor/pump having an input side in fluid communication via a third control valve arrangement with the accumulator hydraulic side and the intensifier hydraulic side, and having an output side in fluid communication via a fourth control valve arrangement with the accumulator hydraulic side and the intensifier hydraulic side;

an electric generator/motor mechanically coupled to the hydraulic motor/pump; and

a control system for actuating the control valve arrangements in a staged manner to provide a predetermined pressure profile to the hydraulic motor input side.

17-27. -27. (canceled)

28. A method of energy storage in a compressed gas storage system that includes an accumulator and an intensifier, the method comprising the steps of:

transferring mechanical energy from a pneumatic side of the accumulator to a hydraulic side of the accumulator at a first pressure ratio;

transferring mechanical energy from a pneumatic side of the intensifier to a hydraulic side of the intensifier at a second pressure ratio greater than the first pressure ratio; and

operating the compressed gas storage system, the accumulator, the intensifier in a staged manner to provide a predetermined pressure profile at at least one outlet.

29-30. -30. (canceled)

31. A compressed gas-based energy storage system comprising a staged hydraulic-pneumatic energy conversion system comprising:

a compressed gas storage system;

at least four hydraulic-pneumatic devices comprising;

a first accumulator having an accumulator pneumatic side and an accumulator hydraulic side, the accumulator pneumatic side and the accumulator hydraulic side being separated by an accumulator boundary mechanism that transfers mechanical energy therebetween;

a second accumulator having an accumulator pneumatic side and an accumulator hydraulic side, the accumulator pneumatic side and the accumulator hydraulic side being separated by an accumulator boundary mechanism that transfers mechanical energy therebetween;

a third accumulator having an accumulator pneumatic side and an accumulator hydraulic side, the accumulator pneumatic side and the accumulator hydraulic side being separated by an accumulator boundary mechanism that transfers mechanical energy therebetween; and

at least one intensifier having an intensifier pneumatic side and an intensifier hydraulic side, the intensifier pneumatic side and the intensifier hydraulic side being separated by an intensifier boundary mechanism that transfers mechanical energy therebetween; and

a control system for operating the compressed gas storage system, the accumulators, and the intensifier in a staged manner such that at least two of the hydraulic-pneumatic devices are always in an expansion phase.

32. The compressed-gas based energy storage system of claim 31 further comprising:

a first hydraulic motor/pump having an input side and an output side; and

a second hydraulic motor/pump having an input side and an output side, wherein at least one of the hydraulic motors/pumps is always being driven by at least one of the at least two hydraulic-pneumatic devices in the expansion phase.

33. The compressed-gas based energy storage system of claim 32, wherein both hydraulic motors/pumps are driven by the at least two hydraulic-pneumatic devices during the expansion phase, each hydraulic motor/pump being driven at a different point during the expansion phase, such that the overall power remains relatively constant.

34. The compressed-gas based energy storage system of claim 32 further comprising:

a first electric generator/motor mechanically coupled to the first hydraulic motor/pump; and

a second electric generator/motor mechanically coupled to the second hydraulic motor/pump, wherein each generator/motor is driven by its respective hydraulic motor/pump, thereby generating electricity.

35. The compressed gas-based energy storage system of claim 32, further comprising a control valve arrangement, responsive to the control system, for variably interconnecting the compressed gas storage system, the hydraulic-pneumatic devices, and the hydraulic motors/pumps.

36-38. -38. (canceled)