Systems and methods for energy storage and recovery using gas expansion and compression

• US 8,448,433 B2
• Filed: 06/07/2011
• Issued: 05/28/2013
• Est. Priority Date: 04/09/2008
• Status: Expired due to Fees

• Current Assignee: SustainX, Inc. (General Compression, Inc.)
• Original Assignee: SustainX, Inc. (General Compression, Inc.)
• Inventors: McBride, Troy O., Bollinger, Benjamin R., Schaefer, Michael, Kepshire, Dax
• Primary Examiner(s): Bomberg, Kenneth
• Assistant Examiner(s): JETTON, CHRISTOPHER M
• Application Number:
  US13/154,996
• Publication Number:
  US 20110296823A1
• Time in Patent Office: 721 Days
• Field of Search: 60407-418, 605/08, 60516-526, 606/45, 606/50, 606/59, 91/4.R, 91/4.A
• US Class Current: 60/508
• CPC Class Codes: F02G 1/02 of open-cycle type
• 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
• CPC Class Codes: H02J 15/006 : in the form of pneumatic energy, e.g. compressed air energy storage [CAES] accumulators for supplying fluid under pressure F15B1/04

Abstract

In various embodiments, energy-storage systems are based upon an open-air arrangement in which pressurized gas is expanded in small batches from a high pressure of, e.g., several hundred atmospheres to atmospheric pressure. The systems may be sized and operated at a rate that allows for near isothermal expansion and compression of the gas.

Claims

1. An energy storage and generation system comprising:

a first pneumatic cylinder assembly for at least one of compressing gas to store energy or expanding gas to recover energy, the first pneumatic cylinder assembly comprising a first compartment, a second compartment, and a piston separating the compartments;

a motor/generator outside the first cylinder assembly;

a transmission mechanism, coupled to the piston and to the motor/generator, for at least one of (i) converting reciprocal motion of the piston into rotary motion of the motor/generator, or (ii) converting rotary motion of the motor/generator into reciprocal motion of the piston;

a heat-transfer subsystem for expediting heat transfer in at least one of the first and second compartments of the first pneumatic cylinder assembly;

a control system for controlling operation of the first pneumatic cylinder assembly to enforce substantially isothermal expansion and compression of gas therein to thereby increase efficiency of the expansion and compression, the control system being responsive to at least one system parameter associated with operation of the first pneumatic cylinder assembly; and

in selective fluid communication with at least one of the first compartment or the second compartment, a vent for at least one of supplying gas for compression or exhausting gas after expansion.

2. The system of claim 1, further comprising a shaft having a first end coupled to the piston and a second end coupled to the transmission mechanism.

3. The system of claim 2, wherein the second end of the shaft is coupled to the transmission mechanism by a crosshead linkage.

4. The system of claim 1, further comprising:

a container for at least one of storage of compressed gas after compression or supply of compressed gas for expansion thereof; and

an arrangement for selectively permitting fluid communication of the container with at least one compartment of the first pneumatic cylinder assembly.

5. The system of claim 1, further comprising a second pneumatic cylinder assembly comprising a first compartment, a second compartment, and a piston (i) separating the compartments and (ii) coupled to the transmission mechanism, wherein the second pneumatic cylinder assembly is fluidly coupled to the first pneumatic cylinder assembly.

6. The system of claim 5, wherein the first and second pneumatic cylinder assemblies are coupled in series.

7. The system of claim 5, wherein the second pneumatic cylinder assembly comprises a second shaft having a first end coupled to the piston of the second pneumatic cylinder assembly and a second end coupled to the transmission mechanism.

8. The system of claim 7, wherein the second end of the second shaft is coupled to the transmission mechanism by a crosshead linkage.

9. The system of claim 1, wherein the transmission mechanism comprises a crankshaft.

10. The system of claim 1, wherein the transmission mechanism comprises a crankshaft and a gear box.

11. The system of claim 1, wherein the transmission mechanism comprises a crankshaft and a continuously variable transmission.

12. The system of claim 1, wherein the heat-transfer subsystem comprises a fluid circulator for pumping a heat-transfer fluid into at least one of the first compartment or the second compartment of the first pneumatic cylinder assembly.

13. The system of claim 12, further comprising a mechanism for introducing the heat-transfer fluid disposed in at least one of the first compartment or the second compartment of the first pneumatic cylinder assembly.

14. The system of claim 13, wherein the mechanism for introducing the heat transfer-fluid comprises at least one of a spray head or a spray rod.

15. The system of claim 1, wherein the transmission mechanism varies torque for a given force exerted thereon.

16. The system of claim 1, further comprising power electronics for adjusting a load on the motor/generator.

17. The system of claim 1, wherein the at least one system parameter comprises at least one of a fluid state, a fluid flow, a temperature, or a pressure.

18. The system of claim 1, further comprising at least one sensor that monitors the at least one system parameter, wherein the control system is responsive to the at least one sensor.

19. The system of claim 5, wherein the control system operates the first pneumatic cylinder assembly and the second pneumatic cylinder assembly in a staged manner in which gas is at least one of compressed or expanded in (i) a first pressure range in the first pneumatic cylinder assembly and (ii) a second pressure range, higher than the first pressure range, in the second pneumatic cylinder assembly.

20. The system of claim 1, further comprising a valve disposed between the vent and the first pneumatic cylinder assembly, the control system operating the vent to supply gas for compression from the atmosphere to the first pneumatic cylinder assembly.