Helium Management Control System

• US 20130019620A1
• Filed: 09/06/2012
• Published: 01/24/2013
• Est. Priority Date: 07/20/2001
• Status: Active Grant

• Current Assignee: Edwards Vacuum, LLC (Atlas Copco AB)
• Original Assignee: Brooks Automation Incorporated (Azenta, Inc.)
• Inventors: Dresens, Paul E., Ash, Gary S., Bartlett, Allen J., Chopy, Joseph Jr., Andeen, Bruce, Than, Y. Robert
• Granted Patent: US 8,869,552 B2
• Time in Patent Office: Days
• US Class Current: 62/115
• CPC Class Codes: B01D 8/00 Cold traps; Cold baffles pumps for evacuating by condensing or freezing F04B37/08
• CPC Class Codes: F04B 37/08 by condensing or freezing, e.g. cryogenic pumps
• CPC Class Codes: F17D 1/04 for distribution of gas
• CPC Class Codes: F17D 3/01 for controlling, signalling, or supervising the conveyance of a product
• CPC Class Codes: F17D 3/18 for measuring the quantity of conveyed product measuring volume or volume flow, in general G01F
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 2110/50 Air quality properties
• CPC Class Codes: F25B 2309/001 with a linear configuration or a linear motor
• CPC Class Codes: F25B 2309/002 with parallel working cold producing expansion devices in one circuit
• CPC Class Codes: F25B 2309/1428 Control of a Stirling refrigeration machine
• CPC Class Codes: F25B 2345/001 Charging refrigerant to a cycle
• CPC Class Codes: F25B 2345/003 Control issues for charging or collecting refrigerant to or from a cycle
• CPC Class Codes: F25B 45/00 Arrangements for charging or discharging refrigerant
• CPC Class Codes: F25B 9/002 characterised by the refrigerant
• CPC Class Codes: F25B 9/14 characterised by the cycle used, e.g. Stirling cycle
• CPC Class Codes: F25J 1/0007 Helium

Abstract

A helium management control system for controlling the helium refrigerant supply from a common manifold supplies cryogenic refrigerators with an appropriate helium supply. The system employs sensors to monitor and regulate the overall refrigerant supply to deliver an appropriate refrigerant supply to each of the cryogenic refrigerators depending on the computed aggregate cooling demand of all of the cryogenic refrigerators. An appropriate supply of helium is distributed to each cryopump by sensing excess and sparse helium and redistributing refrigerant accordingly. If the total refrigeration supply exceeds the demand, or consumption, excess refrigerant is directed to cryogenic refrigerators which can utilize the excess helium to complete a current cooling function more quickly. If the total refrigeration demand exceeds the total refrigeration supply, the refrigerant supply to some or all of the cryogenic refrigerators will be reduced accordingly so that detrimental or slowing effects are minimized based upon the current cooling function.

Claims

1. A system for controlling the supply of refrigerant to a plurality of refrigerators comprising:

a compressor bank including at least one compressor, the compressor including a high pressure supply line and a low pressure exhaust line, the compressor bank capable of supplying a refrigerant;

one or more sensors, in communication with the high pressure supply line and low pressure exhaust line, configured to facilitate determining a differential pressure between the high pressure supply line and the low pressure exhaust line;

a plurality of refrigerators coupled to the compressor bank, the refrigerators capable of consuming the refrigerant; and

an electronic controller configured to respond to the sensor being defective by processing a compressor check routine.

2. The system of claim 1 wherein the refrigerant is helium.

3. The system of claim 2 wherein the compressor check routine prevents damaging operation to the at least one compressor from running without a sufficient supply of helium.

4. The system of claim 1 wherein the compressor check routine includes determining if sensed values from the high pressure supply line supply and low pressure exhaust line pressure, which are used to determine differential pressure, are valid.

5. The system of claim 1 wherein the one or more sensors are configured to facilitate monitoring the supply of refrigerant.

6. The system of claim 1 wherein the refrigerators are configured to alter refrigerant consumption in response to the differential pressure reaching a differential pressure set point.

7. A method for controlling the supply of refrigerant to a plurality of refrigerators, the method including:

monitoring a compressor bank including at least one compressor, the compressor including a high pressure supply line and a low pressure exhaust line, the compressor bank capable of supplying a refrigerant to one or more refrigerators, the refrigerant including helium;

using one or more sensors, determining a pressure differential between the high pressure supply line and the low pressure exhaust line;

detecting that the sensor is defective; and

responding to the detection of the defective sensor by processing a compressor check routine.

8. The method of claim 7 wherein the refrigerant is helium.

9. The method of claim 8 wherein the compressor check routine prevents damaging operation to the at least one compressor from running without a sufficient supply of helium.

10. The method of claim 7 wherein the compressor check routine includes determining if sensed values from the high pressure supply line supply and low pressure exhaust line pressure, used to determine differential pressure, are valid.

11. The method of claim 7 wherein the one or more sensors are configured to facilitate monitoring the supply of refrigerant.

12. The method of claim 7 wherein the refrigerators are configured to alter refrigerant consumption in response to the differential pressure reaching a differential pressure set point.

13. The method of claim 7 further including reducing excess supply of the refrigerant from the compressor bank by decreasing the speed of the at least one compressor.

14. An electronic controller configured to controlling the supply of refrigerant to a plurality of refrigerators, the controller including a non-transitory computer-readable medium having computer readable instructions embodied thereon and configured to:

monitor a compressor bank including at least one compressor, the compressor including a high pressure supply line and a low pressure exhaust line, the compressor bank capable of supplying a refrigerant to one or more refrigerators, the refrigerant including helium;

determine, using one or more sensors, a pressure differential between the high pressure supply line and the low pressure exhaust line;

detect that the sensor is defective; and

respond to the defective sensor by processing a compressor check routine.

15. A system for controlling the supply of refrigerant to a plurality of refrigerators comprising:

a compressor bank including at least one compressor, the compressor including a high pressure supply line and a low pressure exhaust line, the compressor bank capable of supplying a refrigerant;

one or more sensors, in communication with the high pressure supply line and low pressure exhaust line, configured to facilitate determining a differential pressure between the high pressure supply line and the low pressure exhaust line;

a plurality of refrigerators coupled to the compressor bank, the refrigerators capable of consuming the refrigerant; and

an electronic controller configured to respond to the sensor being defective.

16. The system of claim 15 wherein the electronic controller is further configured to response to the defective sensor by processing a compressor check routine.

17. The system of claim 16 wherein the refrigerant is helium.

18. The system of claim 16 wherein the compressor check routine prevents damaging operation to the at least one compressor from running without a sufficient supply of helium.

19. The system of claim 16 wherein the compressor check routine includes determining if sensed values from the high pressure supply line supply and low pressure exhaust line pressure, which are used to determine differential pressure, are valid.

20. The system of claim 15 wherein the one or more sensors are configured to facilitate monitoring the supply of refrigerant.

21. The system of claim 15 wherein the refrigerators are configured to alter refrigerant consumption in response to the differential pressure reaching a differential pressure set point.

22. A method for controlling the supply of refrigerant to a plurality of refrigerators, the method including:

monitoring a compressor bank including at least one compressor, the compressor including a high pressure supply line and a low pressure exhaust line, the compressor bank capable of supplying a refrigerant to one or more refrigerators, the refrigerant including helium;

using one or more sensors, determining a pressure differential between the high pressure supply line and the low pressure exhaust line; and

responding to detecting that the sensor is defective.

23. An electronic controller configured to controlling the supply of refrigerant to a plurality of refrigerators, the controller including a non-transitory computer-readable medium having computer readable instructions embodied thereon and configured to:

monitor a compressor bank including at least one compressor, the compressor including a high pressure supply line and a low pressure exhaust line, the compressor bank capable of supplying a refrigerant to one or more refrigerators, the refrigerant including helium;

determine, using one or more sensors, a pressure differential between the high pressure supply line and the low pressure exhaust line;

detect if the sensor is defective; and

respond to the detected defective sensor.