Subcooling and proportional control of subcooling of liquid refrigerant circuits with thermal storage or low temperature reservoirs

• US 5,386,709 A
• Filed: 12/10/1992
• Issued: 02/07/1995
• Est. Priority Date: 12/10/1992
• Status: Expired due to Fees

• Current Assignee: Baltimore Aircoil Company Incorporated
• Original Assignee: Baltimore Aircoil Company Incorporated
• Inventors: Aaron, David A.
• Primary Examiner(s): WAYNER, WILLIAM E
• Application Number:
  US07/988,547
• Time in Patent Office: 789 Days
• Field of Search: 62/199, 62/79, 62/498, 62/335, 62/59
• US Class Current: 62/199
• CPC Class Codes: F25B 2400/075 with parallel compressors
• CPC Class Codes: F25B 2400/22 Refrigeration systems for supermarkets
• CPC Class Codes: F25B 40/02 Subcoolers
• CPC Class Codes: F25B 5/02 arranged in parallel
• CPC Class Codes: F25B 7/00 Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit F25B9/00 takes precedence
• CPC Class Codes: F25D 16/00 Devices using a combination of a cooling mode associated with refrigerating machinery with a cooling mode not associated with refrigerating machinery
• CPC Class Codes: Y02E 60/14 Thermal energy storage

Abstract

The present invention provides method and apparatus for incorporating thermal storage and other low-temperature reservoirs with new or retrofittable refrigerant circuit devices to increase their thermal operating capacity and efficiency by subcooling refrigerant condensate with subcoolers, as illustrated in a plurality of structural arrangements, which allows simultaneous cooling of a refrigerated volume and recharging of the thermal storage system, and further, it may utilize proportional subcooling to proportionally control evaporator capacity.

Claims

1. An assembly for subcooling liquid condensate of a refrigerant fluid in a refrigerant circuit to provide increased refrigerant-circuit thermal capacity and efficiency, said refrigerant circuit having at least one apparatus operable to refrigerate at least one of a material and volume, said assembly comprising:

thermal storage media, said storage media being one of a chilled fluid and a combination of chilled fluid and frozen material;

means for storing said storage media, said storing means having a housing,

said storage media in said housing,

said at least one refrigerant-operable apparatus having means for condensing said refrigerant fluid to a condensate,

said condensate having a first temperature downstream of said condensing means;

means for coupling;

means for heat exchanging for each said apparatus, each said heat exchange means coupled to said refrigerant circuit by said coupling means for communication of said downstream condensate at said first temperature through said heat exchange means and for return to said refrigerant circuit at a second temperature lower than said first temperature;

said thermal storing means coupled to said heat exchange means by said coupling means;

means for pumping said one of chilled fluid and said combination of chilled fluid and frozen material of said storage media, which storage media is at a third temperature less than said condensate first temperature,

said pumping means coupled between said means for thermal storing and said heat exchange means, and operable to communicate said one of said chilled fluid and, said chilled fluid and frozen material to said heat exchange means to reduce said refrigerant condensate temperature to said second and lower temperature in said heat exchange means,

said one of said chilled fluid and combination of chilled fluid and frozen material downstream of said pump and said heat exchange means communicated to said housing by said coupling means; and

,

means for recharging said thermal storage means, said recharging means operable to reduce said media temperature below said first condensate temperature upstream of said heat exchanger.

2. An assembly for subcooling as claimed in claim 1, wherein said means for heat exchanging is a subcooler.

3. An assembly for subcooling as claimed in claim 2, wherein said subcooler is a counterflow heat exchanger.

4. An assembly for subcooling as claimed in claim 2, wherein said subcooler is a parallel flow heat exchanger.

5. An assembly for subcooling as claimed in claim 2, wherein said subcooler is a cross-flow heat exchanger.

6. An assembly for subcooling liquid condensate of a refrigerant fluid in a refrigerant circuit as claimed in claim 1, said refrigerant circuit further comprising a plurality of apparatus operable with a refrigerant fluid, said assembly for subcooling connected for subcooling said refrigerant fluid to each said apparatus by said coupling means.

7. An assembly for subcooling liquid condensate as claimed in claim 6, wherein said plurality of apparatus has least one refrigerant apparatus and an air-conditioning apparatus.

8. An assembly for subcooling liquid condensate of a refrigerant circuit as claimed in claim 1, which refrigerant circuit is at least one of a refrigeration apparatus and an air-conditioning apparatus.

9. In a cooling and heat exchange system having at least one refrigerant circuit with a refrigerant fluid and, operable at a first fluid flow rate and a reference evaporator capacity,

each said refrigerant circuit having means for evaporating, means for compressing a refrigerant fluid, means for condensing said refrigerant fluid to a condensate at a first temperature downstream of said condensing means, means for expanding said refrigerant fluid condensate, and means for conducting said refrigerant fluid,

said conducting means coupling said evaporating means, said compressing means and said condensing means in said refrigerant circuit, and

means for subcooling said condensate at said first temperature to provide refrigerant fluid condensate to said expansion means at a second temperature less than said condensate first temperature, said subcooling means comprising:

a subcooler coupled to said refrigerant circuit downstream of said condensing means by said conducting means to communicate at least a portion of said refrigerant fluid condensate downstream of said condensing means to said subcooler and to communicate said refrigerant fluid from said subcooler to said refrigerant circuit upstream of said expansion means;

a thermal storage media,

means for thermal storing said thermal storage media at a second temperature less than said condensate first temperature;

said subcooler positioned in said thermal storage unit and operable to reduce said condensate first temperature communicating through said subcooler to said expansion means to provide one of increased refrigerant circuit evaporator capacity at said reference fluid flow rate and the maintenance of system reference evaporator capacity at a reduced system compressor size.

10. In a cooling and heat exchange system as claimed in claim 9, further comprising means for controlling fluid flow between said means for subcooling and said conducting means.

11. In a cooling and heat exchange system as claimed in claim 10, wherein said means for controlling fluid flow has at least one valve in said conducting means;

means for sensing operable to provide a signal;

a first line;

a signal source coupled to said sensing means by said first line and operable to receive said signal;

a second line;

said signal source coupled to said at least one valve by said second line and operable in response to said signal to modulate said refrigerant flow through said subcooling means to control said reduced condensate temperature to said expansion device.

12. In a subcooling and heat exchange system as claimed in claim 10, wherein said means for controlling fluid flow has a first valve in said conducting means in parallel with said subcooling means and operable to divert flow to said subcooling means;

a first line;

means for sensing operable to provide a sensed signal;

a signal source coupled to said sensing means by said first line to receive said sensed signal;

a second line connecting said signal source to said first valve to communicate an actuation signal to actuate said first valve;

a second valve in said conducting means downstream of said first valve and subcooling means;

a third line coupled between said signal source and said second valve, which second valve in response to a signal from said signal source is operable to modulate said refrigerant flow through said subcooling means to control said condensate temperature to said expansion device.

13. A subcooling and heat exchange system having at least one refrigerant circuit with a refrigerant fluid and operable at a first fluid flow rate and a reference evaporator capacity,

each said refrigerant circuit having means for evaporating, means for compressing a refrigerant fluid with a compressor capacity, means for condensing said refrigerant fluid condensate, and means for conducting said refrigerant fluid, said fluid conducting means operable to couple said evaporator means, said compressing means and said condensing means, and

means for providing reduced temperature refrigerant to said expanding means, said system comprising:

means for subcooling coupled to said refrigerant circuit between said condensing means and said expanding means by said conducting means, said subcooling means operable to receive at least a portion of said refrigerant fluid condensate downstream of said condensing means;

said condensate downstream from said condensing means at a first temperature;

.

a thermal storage system having a thermal storage housing and thermal storage media in said housing at a second temperature, which is about at a freezing point of said storage media, and less than said condensate first temperature;

second means for conducting coupled between said thermal storage system and said subcooling means to communicate fluid storage media from said thermal storage system to said subcooling means and to communicate said fluid storage media from said subcooling means to said thermal storage housing;

said subcooling means operable to reduce said refrigerant fluid condensate first temperature to a third temperature less than said first temperature and communicate said fluid condensate at said third temperature to said expansion means of said coupled refrigerant circuit at a temperature less than said first temperature to provide said refrigerant circuit one of increased evaporator capacity at said first refrigerant flow rate and the maintenance of about the reference evaporator means capacity at a reduced compressor capacity.

14. A subcooling and heat exchange system as claimed in claim 13 further comprising a pump in said second means for conducting, said pump operable to pump said fluid media through said second means for conducting.

15. A subcooling and heat exchange system as claimed in claim 14 further comprising a plurality of refrigerant circuits;

each said circuit having means for subcooling and a pump in said second conducting means coupled to said thermal storage unit, which pump is operable to pump said fluid media through each said subcooling and second conducting means.

16. A subcooling and heat exchange system as claimed in claim 15 wherein at least one of said plurality of refrigerant circuits is an air-conditioning apparatus.

17. A subcooling and heat exchange system as claimed in claim 15 wherein each said refrigerant circuit has means for controlling and selectively diverting refrigerant fluid flow through said means for subcooling and said means for conducting.

18. A subcooling and heat exchange system as claimed in claim 17 wherein said means for controlling and diverting refrigerant flow is a control valve.

19. A subcooling and heat exchange system as claimed in claim 17 wherein said means for controlling is a solenoid-operated valve.

20. A subcooling and heat exchange system as claimed in claim 17 further comprising means for sensing operable to provide a sensed signal, means for connecting, and at least one signal source to provide an actuation signal;

said means for sensing connected to said signal source by said connecting means to provide said sensed signal to said signal source;

said connecting means coupling said signal source to said controlling means to communicate said actuation signal to operate said controlling means.

21. A subcooling and heat exchange system as claimed in claim 20 wherein said controlling means in each said circuit is a control valve operable to modulate said refrigerant condensate flow through said subcooling means and said conducting in each said refrigerant circuit.

22. A subcooling and heat exchange system as claimed in claim 13 wherein said fluid media is water.

23. A subcooling and heat exchange system as claimed in claim 13 wherein said fluid media is a mixture of glycol and water.

24. In a cooling and heat exchange system having at least one refrigerant circuit with a refrigerant fluid, and means for subcooling operable to reduce the temperature of said refrigerant fluid from a first temperature to a second temperature,

each said refrigerant circuit having means for evaporating said refrigerant fluid, means for compressing said evaporated refrigerated fluid, means for condensing said evaporated refrigerated fluid to a condensate at a first temperature, means for expanding said condensate, and means for conducting said refrigerant fluid,

said conducting means coupling said evaporating means, said compressing means, said condensing means and said expanding means for operation in said refrigerant circuit,

said refrigerant circuit operable at a first fluid flow rate and a reference evaporator capacity,

said subcooling means comprising:

a thermal storage media at a third temperature, less than said condensate first temperature;

means for storing said thermal storage media at a temperature less than said condensate first temperature;

means for recharging said media to said third temperature in said means for thermal storing;

a subcooler coupled by said conducting means to receive at least a portion of said condensate fluid at said first temperature downstream of said condensing means,

said subcooler operable to reduce said first temperature of said condensate communicating through said subcooler to said expansion device and, to provide one of increased evaporator capacity at said first reference fluid flow rate and the maintenance of said reference evaporator capacity at a reduced size for said compressing means.