Systems and methods for temperature control

• US 6,775,996 B2
• Filed: 02/22/2002
• Issued: 08/17/2004
• Est. Priority Date: 02/22/2002
• Status: Expired due to Term

• Current Assignee: B/E Aerospace, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Advanced Thermal Sciences Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Cowans, Kenneth W.
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US10/079,542
• Publication Number:
  US 20030159456A1
• Time in Patent Office: 907 Days
• Field of Search: 621/59, 621/60, 621/964, 622/381, 622/386, 622/387, 621/961, 621/963, 622/01, 621/85, 62/98, 622/591, 622/592
• US Class Current: 62/160
• CPC Class Codes: B23Q 11/141 using a closed fluid circuit for cooling or heating
• CPC Class Codes: B23Q 11/143 comprising heating means
• CPC Class Codes: F25B 2400/01 Heaters
• CPC Class Codes: F25B 2400/0403 for the condenser
• CPC Class Codes: F25B 2400/0409 for the evaporator
• CPC Class Codes: F25B 2400/0411 for the expansion valve or capillary tube
• CPC Class Codes: F25B 25/005 using primary and secondary systems
• CPC Class Codes: F25B 2700/1933 Suction pressures
• CPC Class Codes: F25B 2700/21151 at the suction side of the compressor
• CPC Class Codes: F25B 2700/21173 at the outlet
• CPC Class Codes: F25B 40/00 Subcoolers, desuperheaters or superheaters
• CPC Class Codes: F25B 41/20 Disposition of valves, e.g. of on-off valves or flow control valves expansion valves F25B41/31
• CPC Class Codes: F25D 17/02 for circulating liquids, e.g. brine

Abstract

The problem of controlling the temperature of the different units in a process tool system which have to be cooled or heated using thermal transfer fluid at selected setpoints and flow rates is resolved by a system having multiple modular units each with some operative and form factor commonality but at least dual functional capability. The modular units each have separate recirculation loops for thermal transfer fluid but cool the fluid using refrigeration cycles or facilities water supplies or heat the fluid using compressed hot gases or electrical energy. By employing operative units which can be internally varied to provide different thermal capacities within form factor constraints, the system enables concurrent temperature control needs of a number of different units to be met with an energy efficient, low footprint, highly adaptable system.

Claims

1. A temperature control unit for supplying thermal transfer fluid at a specified temperature and with a needed flow rate to more than one unit in a process tool and configured such that the thermal transfer fluid is temperature controllable with energy efficiency in temperature ranges from low temperature chilling to high temperature heating, comprising:

a first temperature control module having a refrigeration loop including a compressor, condenser and evaporator/heat exchanger, and including a condenser bypass loop for providing pressurized hot gas refrigerant, the first module also including a thermal transfer fluid reservoir, a pump for the thermal transfer fluid and a first conduit system directing the thermal transfer fluid through the evaporator/heat exchanger in heat exchange relation to the refrigerant, and a second conduit system for alternatively directing refrigerant as a hot gas from the compressor through the evaporator/heat exchanger; and

a second temperature control module having a thermal transfer fluid reservoir, a liquid/liquid heat exchanger, a pump for the thermal transfer fluid loop directing thermal transfer fluid through the heat exchanger, and a water cooling loop receiving facilities water at available temperature and directing it through the heat exchanger in thermal exchange relation with the thermal transfer fluid.

2. A temperature control unit as set forth in claim 1 above, including a control chassis having module receptacles with standard form factors in width and depth, and wherein the first and second control modules have form factors fitting within the receptacles to permit interchangeability.

3. A temperature control unit as set forth in claim 1 above, including an expansion valve in the refrigerant loop for varying the refrigerant flow to adjust the thermal transfer fluid to the specified temperature level, and also including a water flow control valve in the water cooling loop to adjust the thermal transfer fluid to its specified temperature level.

4. A temperature control unit as set forth in claim 1 above, wherein the first temperature control module includes a hot gas bypass valve in the second conduit system and responsive to the compressor input pressure, and wherein the second conduit system from the compressor output is directed serially through the thermal transfer fluid reservoir and through the evaporator/heat exchanger to sweep out oil contained in the refrigerant while heating the thermal transfer fluid.

5. A temperature control unit as set forth in claim 1 above, wherein each of the control modules includes a heating element in the first conduit system for adding thermal energy when needed to raise the temperature to a specified level for that module.

6. A temperature control unit as set forth in claim 5 above, wherein the compressor power of the first control module is selected to provide cooling to a selected low temperature level, and the first control module provides heating to a selected maximum temperature level with a combination of pressurized hot gas and heating from the heating element, and wherein the second control module provides cooling to a minimum level determined by the temperature of the facilities water and heating with the heating element.

7. A temperature control unit as set forth in claim 1 above, wherein the control modules each include supply and return manifolds for coupling thermal transfer fluid to and from more than one process tool and wherein the unit further includes a processor system responsive to the chosen setpoints and to thermal transfer fluid temperatures for controlling the coolant flows in the first and second temperature control modules.

8. A temperature control system for alternative control of the temperature of a process tool by chilling or heating using a cycling thermal transfer fluid comprising:

a refrigeration loop for flowing a refrigerant and including a compressor, a condenser in series therewith, a refrigerant flow control, and an evaporator/heat exchanger;

a thermal transfer fluid loop comprising a fluid reservoir, a pump, and connections for cycling the fluid to and from the process tool, the fluid loop being directed through the evaporator/heat exchanger;

a bypass path for pressurized hot gas refrigerant from the compressor to the evaporator/heat exchanger; and

a hot gas bypass valve responsive to the input pressure of refrigerant to the compressor for directing hot gas into the bypass path, such that compressor energy is used for cooling when the flow control is used and heating when the flow control shuts off refrigerant flow.

9. A temperature control system as set forth in claim 8 above, wherein the bypass path extends through the reservoir prior to coupling to the evaporator/heat exchanger and the system includes a desuperheater valve responsive to refrigerant temperature at the compressor input for directing refrigerant output from the condenser to the compressor input.

10. A temperature control system as set forth in claim 9 above, wherein the system further includes a heater in the thermal transfer fluid loop, and a subcooler in the refrigeration loop, the subcooler being disposed to effect thermal energy interchange between return flow from the evaporator/heat exchanger to the compressor and refrigerant supplied to the evaporator/heat exchanger form the condenser.

11. A temperature control system as set forth in claim 10 above, wherein the refrigerant flow control comprises a solenoid expansion valve operating in a variable duty cycle mode, and the system further includes a high pressure relief valve in the refrigeration loop.

12. The method of controlling the temperature of a process tool with a thermal transfer fluid supplied from a reservoir, comprising the steps of:

pressurizing a refrigerant to provide pressurized hot gas;

when the process tool is to be heated, extracting pressurized hot gas for heating the thermal transfer fluid from the reservoir while first preheating the fluid in the reservoir by passing the hot gas through the reservoir;

when the process tool is to be cooled, condensing the pressurized hot gas to a liquid pressurized refrigerant, and

controllably alternatively directing the hot gas or the liquid pressurized refrigerant in heat exchange relation to the thermal transfer fluid to heat or chill the thermal transfer fluid to a selected temperature level before application to the process tool.

13. A method as set forth in claim 12 above, wherein the step of directing the refrigerant in heat exchange relation comprises passing the refrigerant in evaporative relation to the thermal transfer fluid.

14. A method as set forth in claim 13 above, including the further step of cooling by subcooling liquid pressurized refrigerant with refrigerant returning from heat exchange with the thermal transfer fluid.

15. A method as set forth in claim 12 above, including the step of adding electrical heat energy to the thermal transfer fluid when heating the thermal transfer fluid with hot gas.

16. A method as set forth in claim 12 above, wherein the pressurized hot gas is in the range of up to about 120°

C. and wherein the method includes the further steps of sensing when the refrigerant to be pressurized is in excess of predetermined temperature, and adding pressurized liquid refrigerant thereto before pressurizing.

17. A method for controlling the operating temperature of a process tool in a range from about −

40°

C. to about +120°

C. using a fluid reservoir for thermal transfer fluid moving in a loop through the process tool and a refrigeration loop including a compressor, condenser, evaporator/heat exchanger and a controllable expansion valve for controlling the flow of pressurized liquid refrigerant to the evaporator/heat exchanger, comprising the steps of;

generating an indication of the difference between the desired and actual temperature thermal transfer fluid to be supplied to for the process tool;

passing the thermal transfer fluid through the evaporator/heat exchanger;

controlling, by use of the expansion valve, the rate of evaporation of the condensed refrigerant in the evaporator/heat exchanger based upon the difference indication when the desired temperature is in a low temperature zone;

extracting a hot gaseous refrigerant flow from the compressor for use in heating the thermal transfer fluid when the desired temperature is in a median temperature zone;

passing the hot gaseous refrigerant through the reservoir contents in heat exchange relation with the thermal transfer fluid;

adding heat to the heat transfer fluid to raise the temperature of the process tool to a high temperature zone, and

flowing the thermal transfer fluid through the process tool to regulate the temperature of the process tool.