VALVES

• US 20130118344A1
• Filed: 07/27/2011
• Published: 05/16/2013
• Est. Priority Date: 07/29/2010
• Status: Active Grant

• Current Assignee: Isentropic, Ltd.
• Original Assignee: Isentropic, Ltd.
• Inventors: Howes, Jonathan Sebastian, Macnaghten, James
• Granted Patent: US 9,551,219 B2
• Time in Patent Office: Days
• US Class Current: 91/55
• CPC Class Codes: F01B 1/01 with one single cylinder
• CPC Class Codes: F01B 17/02 Engines
• CPC Class Codes: F01B 29/04 characterised by means for converting from one type to a different one
• CPC Class Codes: F01K 13/02 Controlling, e.g. stopping or starting
• CPC Class Codes: F01K 7/00 Steam engine plants characterised by the use of specific types of engine F01K3/02 takes precedence; Plants or engines characterised by their use of special steam systems, cycles or processes reciprocating-piston engines using uniflow principle F01B17/04; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating
• CPC Class Codes: F04B 49/22 by means of valves F04B49/03 takes precedence

Abstract

An apparatus (10) for compressing and expanding a gas includes a chamber (22), a positive displacement device (24) moveable relative thereto, first and second valves (26, 28) activatable to control flow of gas into and out of the chamber (22) and a controller (80) for controlling activation of the valves (26, 28) that selectively switches operation between a compression and an expansion mode with selective switching between modes being achieved by selectively changing the activation timing of at least one of the valves during the first mode. An energy storage system including the device may be operatively coupled via a rotary device for power transmission to an input/output device, whereby the direction and speed of rotation are preserved during switching, and the input/output device may be synchronised to the grid.

Claims

1. Apparatus for gas compression and expansion, comprising:

a chamber for receiving a gas;

a positive displacement device moveable relative to the chamber;

first and second valves activatable to control gas flow into and out of the chamber; and

a controller configured to control activation timing of the first and second valves;

wherein the controller is configured to selectively switch operation of the positive displacement device between a compression mode in which the gas received in the chamber is compressed by the positive displacement device and an expansion mode in which the gas received in the chamber is expanded by the positive displacement device, and wherein the controller is configured to selectively change the activation timing of at least one of the first and second valves during operation in a first mode of the compression and expansion modes to selectively switch from the first mode to a second mode of the compression and expansion modes.

2. Apparatus according to claim 1, wherein the positive displacement device is coupled to a rotary device for transmitting mechanical power between the positive displacement device and an input/output device and the controller is configured to selectively switch from the first mode to the second mode of operation whilst the rotary device continues to move in a predetermined direction associated with the first mode.

3. Apparatus according to claim 1, wherein the first and second valves are configured to selectively connect the chamber to either a high pressure region or a low pressure region.

4. Apparatus according to claim 3, wherein the apparatus is configured to allow only one of the low pressure and high pressure regions to be connected to the chamber at any one time.

5. Apparatus according to claim 4, wherein the controller is configured to close a connection to one region if the switching operation requires a connection to the other region to be opened.

6. Apparatus according to claim 1, wherein the controller is configured to provide a valve closure signal for a further mode without switching the operation of the positive displacement device.

7. Apparatus according to claim 1, wherein the controller is additionally configured to selectively switch the operation of the positive displacement device to an unloaded mode in which energy consumption is minimised.

8. Apparatus according to claim 1, wherein the apparatus further comprises:

a further chamber for receiving a gas;

a further positive displacement device moveable relative to the further chamber; and

third and fourth valves activatable to control gas flow into and out of the further chamber;

wherein the controller is configured to selectively switch operation of the further positive displacement device between a compression mode in which the gas received in the further chamber is compressed by the further positive displacement device and an expansion mode in which the gas received in the further chamber is expanded by the further positive displacement device, and wherein the controller is configured to selectively change the activation timing of at least one of the third and fourth valves during operation in a first mode of the compression and expansion modes to selectively switch from the first mode to a second mode of the compression and expansion modes.

9. Apparatus according to claim 8, wherein the controller is configured to switch operation of each of the first-mentioned positive displacement device and the further positive displacement device from the first mode to the second mode at substantially the same time.

10. Apparatus according to claim 9, wherein the first mode of the first-mentioned positive displacement device and the first mode of the further positive displacement device are corresponding modes.

11. Apparatus according to claim 9, wherein the first mode of the first-mentioned positive displacement device and the first mode of the further positive displacement device are opposite modes.

12. Energy storage apparatus comprising apparatus according to claim 1.

13. A pumped heat storage system comprising apparatus according to claim 8 and operable in a charging mode to store electrical energy as thermal energy, and operable in a discharging mode to generate electrical energy from the stored thermal energy, the pumped heat storage system comprising a high pressure store and a lower pressure store, wherein the first-mentioned positive displacement device and the further positive displacement device are respectively configured to act in the respective compression mode and the respective expansion mode during the charging mode and vice versa in the discharging mode.

16. Apparatus according to claim 2, in which the input/output device comprises a grid synchronised motor/generator capable of switching between operation as a motor and a generator during a switch between the compression and expansion modes without losing grid synchronisation.

17. Apparatus according to claim 1, wherein at least one of the first and second valves is configured to open when gas pressures on either side of said at least one valve are substantially equal and wherein the controller is configured to alter a valve closure timing of said at least one valve to selectively switch from the first mode to the second mode.

18. Apparatus according to claim 17, wherein at least one of the first and second valves is configured to self-open when gas pressures on either side of said at least one valve are substantially equal.

19. Apparatus according to claim 1, wherein the apparatus forms part of a reversible system configured such that, upon switching between the compression and expansion modes, functions of the first and second valves are reversed and the gas flows through the apparatus in a reversed direction.

20. Apparatus according to claim 1, wherein in the compression mode the controller is configured to fire a valve shut late to reduce overall capacity of gas compression to partially unload the apparatus such that the apparatus is operable in a part loaded manner.

21. Apparatus according to claim 1, wherein in the expansion mode the controller is configured to fire a valve shut early to reduce overall capacity of gas expansion to partially unload the apparatus such that the apparatus is operable in a part loaded manner.

14. (canceled)

15. (canceled)

22. A method of gas compression and expansion, the method comprising:

receiving a gas in a chamber for which first and second valves are operable to control gas flow into and out of the chamber; and

selectively changing, with a controller, an activation timing of at least one of the first and second valves to selectively switch operation of a positive displacement device moveable relative to the chamber between a compression mode in which the gas received in the chamber is compressed by the positive displacement device and an expansion mode in which the gas received in the chamber is expanded by the positive displacement device, wherein the activation timing is changed during the operation of the positive displacement device in one of the compression and expansion modes.