Refrigeration system with auxiliary defrost heat tank

• US 3,922,875 A
• Filed: 09/12/1974
• Issued: 12/02/1975
• Est. Priority Date: 09/12/1974
• Status: Expired due to Term

• Current Assignee: William F. Morris Jr
• Original Assignee: William F. Morris Jr
• Inventors: Morris, William F. Jr.
• Primary Examiner(s): Wye, William J.
• Application Number:
  US05/505,347
• Time in Patent Office: 446 Days
• Field of Search: 62/278,81,80,276,277,351,352,151,156
• US Class Current: 62/156
• CPC Class Codes: F25B 2400/051 between the accumulator and another part of the cycle
• CPC Class Codes: F25B 40/00 Subcoolers, desuperheaters or superheaters
• CPC Class Codes: F25B 43/006 Accumulators
• CPC Class Codes: F25B 47/022 hot gas defrosting

Abstract

A refrigeration system adapted to cycle alternately through a refrigeration cycle and a defrost cycle, wherein a suction accumulator tank is provided in the suction line between the evaporator and the compressor to receive any liquid refrigerant discharged from the evaporator toward the compressor during the hot gas defrost cycle. An auxiliary defrost heat tank is connected to the suction accumulator tank having a coil immersed in a heated heat storage liquid to receive liquid refrigerant from the suction accumulator when the liquid level in the latter exceeds a predetermined reference level and evaporates the liquid refrigerant for return in gaseous state to the suction accumulator.

Claims

1. A refrigeration system adapted to cycle alternately through a refrigeration cycle and a defrost cycle, comprising a compressor having discharge and suction ports, a condenser connected to the discharge port to receive refrigerant gas from the compressor during the refrigerant cycle and condense the same, an evaporator having an inlet connected to the condenser to receive condensed liquid refrigerant therefrom during the refrigeration cycle and having an outlet, hot gas conduit means for conveying gaseous refrigerant from the compressor to the evaporator during the defrost cycle, a suction accumulator tank connected by an outlet suction line to the suction port of the compressor and by an inlet suction line to the evaporator outlet for receiving any liquid refrigerant discharged from the evaporator outlet toward the compressor and having means for conveying warm liquid refrigerant coursing from the condenser to the evaporator therethrough in heat exchange relation with liquid refrigerant in the accumulator tank received from the evaporator outlet to vaporize the latter, an auxiliary defrost heat tank connected to said suction accumulator tank substantially filled with a heat storage liquid and having a conduit coil immersed therein connected by a feed line to said accumulator tank at a location slightly above a reference liquid level therein normally reached by the liquid refrigerant during the refrigeration cycle to convey liquid refrigerant during the defrost cycle to the heat tank only when the liquid refrigerant level in the accumulator tank exceeds said reference level, means for heating said heat storage liquid in said heat tank to a sufficient temperature for promptly vaporizing any liquid refrigerant conveyed into said conduit coil thereIn, and a heat tank outlet conduit for return of the vaporized refrigerant from the conduit coil in the heat tank to the suction port of said compressor.

2. A refrigeration system as defined in claim 1, wherein said heat tank includes an electric heating element immersed in the heat storage liquid therein to heat the same to a predetermined temperature for vaporizing the liquid refrigerant conveyed into said conduit coil.

3. A refrigeration system as defined in claim 2, including thermostatic control means for controlling electric supply to said heating element to attain temperature in said heat storage liquid in the range of about 150*F to 180*F.

4. A refrigeration system as defined in claim 1, wherein said means for heating said heat storage liquid in said heat tank comprises conduit means extending therethrough for conveying hot gaseous refrigerant from said discharge port of said compressor before delivery of the hot gaseous refrigerant to said condenser or said evaporator to heat the heat storage liquid to a temperature range of about 150*F to 180*F.

5. A refrigeration system as defined in claim 1, wherein all of said conduit coil in said heat tank is located below the horizontal level of the feed line connection to said accumulator tank for gravity feed of the liquid refrigerant from the accumulator tank to the conduit coil in said heat tank when the liquid refrigerant level in the accumulator tank exceeds said reference liquid level.

6. A refrigeration system as defined in claim 3, wherein all of said conduit coil in said heat tank is located below the horizontal level of the feed line connection to said accumulator tank for gravity feed of the liquid refrigerant from the accumulator tank to the conduit coil in said heat tank when the liquid refrigerant level in the accumulator tank exceeds said reference liquid level.

7. A refrigeration system as defined in claim 4, wherein all of said conduit coil in said heat tank is located below the horizontal level of the feed line connection to said accumulator tank for gravity feed of the liquid refrigerant from the accumulator tank to the conduit coil in said heat tank when the liquid refrigerant level in the accumulator tank exceeds said reference liquid level.

8. A refrigeration system as defined in claim 1, wherein said heat tank outlet conduit comprises a return line from a return end of said conduit coil to said inlet suction line immediately upstream from the connection of the latter to said suction accumulator tank to return the vaporized refrigerant from said conduit coil to the upper portion of said suction accumulator tank for return to the compressor.

9. A refrigeration system as defined in claim 3, wherein said heat tank outlet conduit comprises a return line from a return end of said conduit coil to said inlet suction line immediately upstream from the connection of the latter to said suction accumulator tank to return the vaporized refrigerant from said conduit coil to the upper portion of said suction accumulator tank for return to the compressor.

10. A refrigeration system as defined in claim 4, wherein said heat tank outlet conduit comprises a return line from a return end of said conduit coil to said inlet suction line immediately upstream from the connection of the latter to said suction accumulator tank to return the vaporized refrigerant from said conduit coil to the upper portion of said suction accumulator tank for return to the compressor.

11. A refrigeration system adapted to cycle alternately through a refrigeration cycle and a defrost cycle, comprising a compressor having discharge and suction ports, a condenser connected to the discharge port to receive refrigerant gas from the compressor during the refrigerant cycle and condense the same, an evaporator having an inlet connected to the condenser to receive condensed liquid refrigerant therefrom during the refrigeration cycle and having an outlet, hot gas conduit means for conveyiNg gaseous refrigerant from the compressor to the evaporator during the defrost cycle, a suction accumulator tank connected by an outlet suction line to the suction port of the compressor and by an inlet suction line to the evaporator outlet for receiving any liquid refrigerant discharged from the evaporator outlet toward the compressor, an auxiliary defrost heat tank connected to said suction accumulator tank substantially filled with a heat storage liquid and having a conduit coil immersed therein connected by a feed line to said accumulator tank at a location slightly above a reference liquid level therein normally reached by the liquid refrigerant during the refrigeration cycle to convey liquid refrigerant during the defrost cycle to the heat tank only when the liquid refrigerant level in the accumulator tank exceeds said reference level, means for heating said heat storage liquid in said heat tank to a sufficient temperature for promptly vaporizing any liquid refrigerant conveyed into said conduit coil therein, and a heat tank outlet conduit for return of the vaporized refrigerant from the conduit coil in the heat tank to the suction port of said compressor.

12. A refrigeration system as defined in claim 11, wherein said heat tank includes an electric heating element immersed in the heat storage liquid therein to heat the same to a predetermined temperature for vaporizing the liquid refrigerant conveyed into said conduit coil.

13. A refrigeration system as defined in claim 12, including thermostatic control means for controlling electric supply to said heating element to attain temperature in said heat storage liquid in the range of about 150*F to 180*F.

14. A refrigeration system as defined in claim 11, wherein said means for heating said heat storage liquid in said heat tank comprises conduit means extending therethrough for conveying hot gaseous refrigerant from said discharge port of said compressor before delivery of the hot gaseous refrigerant to said condenser or said evaporator to heat the heat storage liquid to a temperature range of about 150*F to 180*F.

15. A refrigeration system as defined in claim 11, wherein all of said conduit coil in said heat tank is located below the horizontal level of the feed line connection to said accumulator tank for gravity feed of the liquid refrigerant from the accumulator tank to the conduit coil in said heat tank when the liquid refrigerant level in the accumulator tank exceeds said reference liquid level.

16. A refrigeration system as defined in claim 13, wherein all of said conduit coil in said heat tank is located below the horizontal level of the feed line connection to said accumulator tank for gravity feed of the liquid refrigerant from the accumulator tank to the conduit coil in said heat tank when the liquid refrigerant level in the accumulator tank exceeds said reference liquid level.

17. A refrigeration system as defined in claim 14, wherein all of said conduit coil in said heat tank is located below the horizontal level of the feed line connection to said accumulator tank for gravity feed of the liquid refrigerant from the accumulator tank to the conduit coil in said heat tank when the liquid refrigerant level in the accumulator tank exceeds said reference liquid level.

18. A refrigeration system as defined in claim 11, wherein said heat tank outlet conduit comprises a return line from a return end of said conduit coil to said inlet suction line immediately upstream from the connection of the latter to said suction accumulator tank to return the vaporized refrigerant from said conduit coil to the upper portion of said suction accumulator tank for return to the compressor.

19. A refrigeration system as defined in claim 13, wherein said heat tank outlet conduit comprises a return line from a return end of said conduit coil to said inlet suction line immediately upstream from the connection of the latter to said suction accumulator tank to return the vaporized Refrigerant from said conduit coil to the upper portion of said suction accumulator tank for return to the compressor.

20. A refrigeration system as defined in claim 14, wherein said heat tank outlet conduit comprises a return line from a return end of said conduit coil to said inlet suction line immediately upstream from the connection of the latter to said suction accumulator tank to return the vaporized refrigerant from said conduit coil to the upper portion of said suction accumulator tank for return to the compressor.