Transcritical thermally activated cooling, heating and refrigerating system

Abstract

A combined vapor compression and vapor expansion system uses a common refrigerant which enables a super-critical high pressure portion and a sub-critical low pressure portion of the vapor expansion circuit. Provision is made to combine the refrigerant flow from the vapor expander and from the compressor discharge. The outdoor heat exchanger is so sized and designed that the working fluid discharged therefrom is always in a liquid form so as to provide a liquid into the pump inlet. The pump and expander are so sized and designed that the high pressure portion of the vapor expansion circuit is always super-critical. A topping heat exchanger, liquid to suction heat exchanger, and various other design features are provided to further increase the thermodynamic efficiency of the system.

we claim: 
     
         1 . A thermally activated cooling system comprising:
 a vapor compression circuit which includes, in serial flow relationship, a compressor, a first heat exchanger, an expansion device and a second heat exchanger;   a vapor expansion circuit which includes, in serial flow relationship, a liquid refrigerant pump, a heater, an expander, and said first heat exchanger;   said vapor compression circuit and said vapor expansion circuit each having a common refrigerant circulating therethrough as a working fluid; wherein said refrigerant enables supercritical high pressure portion and sub-critical low pressure portion of the vapor compression circuit   said compressor having a suction inlet and a discharge outlet, and said expander having an inlet and an outlet, and further wherein said expander outlet is fluidly connected to said compressor outlet to provide a combined flow for circulation of a portion of said working fluid through said first heat exchanger and to said pump wherein said first heat exchanger is so sized, and designed such that the working fluid discharged therefrom is always in a liquid form; and   said pump and said expander are so sized and designed that the high pressure portion of said vapor expansion circuit is always super-critical.   
     
     
         2 . A thermally activated cooling system as set forth in  claim 1  where said common refrigerant is CO 2 . 
     
     
         3 . A thermally activated cooling system as set forth in  claim 1  where said common refrigerant is a mixture of CO 2  and propane. 
     
     
         4 . A thermally activated cooling system as set forth in  claim 1  and including a topping heat exchange for causing heat to flow from the expander discharge stream to the stream flowing to the heater. 
     
     
         5 . A thermally activated cooling system as set forth in  claim 1  and including a liquid-to-suction heat exchanger for causing the flow of heat from the condenser discharge stream to the evaporator discharge stream. 
     
     
         6 . A thermally activated cooling system as set forth in  claim 1  wherein said expander is a two stage expander and further wherein a second heater is provided between the two stages. 
     
     
         7 . A thermally activated cooling system as set forth in  claim 1  and including a second vapor compression circuit in parallel with said vapor compression circuit, said second vapor compression circuit having its own expansion device, evaporator, and compressor fluidly interconnected to function with said first heat exchanger. 
     
     
         8 . A thermally activated cooling system as set forth in  claim 1  and including a plurality of valves for selectively causing the vapor compression system to function as a heat pump. 
     
     
         9 . A thermally activated cooling system as set forth in  claim 8  wherein said plurality of valves includes two expansion devices, one for the first heat exchanger and another for said second heat exchanger. 
     
     
         10 . A thermally activated cooling system as set forth in  claim 8  wherein said plurality of valves includes a single bidirectional expansion device which is selectively operated to conduct the flow of refrigerant to either said first or second heat exchanger. 
     
     
         11 . A thermally activated cooling system as set forth in  claim 8  wherein said plurality of valves comprises a plurality of check valves that are selectively operated to conduct the flow of refrigerant to either the first or second heat exchanger. 
     
     
         12 . A thermally activated cooling system as set forth in  claim 1  and including a second heater connected in serial flow relationship with said heater. 
     
     
         13 . A thermally activated cooling system as set forth in  claim 1  wherein said compressor comprises a multi-stage compressor, and further including a gas cooler operably connected between said stages. 
     
     
         14 . A thermally activated cooling system as set forth in  claim 1  wherein said compression circuit includes an ejector for boosting the flow of refrigerant to said compressor. 
     
     
         15 . A thermally activated cooling system as set forth in  claim 14  wherein a refrigerant stream intended for cooling duty is split into two portions; said ejector is powered by one portion of said refrigerant stream and ejects another portion of said refrigerant stream processed in said evaporator and then in said liquid-to-suction heat exchanger. 
     
     
         16 . A thermally activated cooling system as set forth in  claim 14  wherein said compression circuit includes a suction accumulator; a refrigerant stream intended for cooling duty powers said ejector ejects liquid portion of said stream collected in said suction accumulator and processed in said evaporator. 
     
     
         17 . A thermally activated cooling system as set forth in  claim 1  wherein said vapor compression circuit includes an economizer operably connected therewith. 
     
     
         18 . A thermally activated cooling system as set forth in  claim 1  and including a two phase expander fluidly interconnected between said condenser and said evaporator. 
     
     
         19 . A thermally activated cooling system as set forth in  claim 1  wherein said expander, said pump, and said compressor have a common shaft 
     
     
         20 . A thermally activated cooling system as set forth in  claim 1  wherein a power generator and said expander have a common shaft and said power generator powers said pump and said compressor. 
     
     
         21 . A thermally activated cooling system as set forth in  claim 1  wherein a power generator, said expander, and said pump have a common shaft and said power generator powers said compressor. 
     
     
         22 . A thermally activated cooling system as set forth in  claim 1  wherein a power generator, said expander, and said compressor have a common shaft and said power generator feeds said pump. 
     
     
         23 . A thermally activated cooling system as set forth in  claim 18  wherein said expander, said pump, and said compressor have a common hermetic casing. 
     
     
         24 . A power generation vapor expansion circuit which includes, a power generator and, in serial flow relationship, a liquid refrigerant pump, a heater, an expander, and a heat exchanger;
 a refrigerant circulating therethrough as a working fluid wherein said refrigerant enables supercritical high pressure portion and sub-critical low pressure portion of the vapor expansion circuit;   said first heat exchanger is so sized, and designed such that the working fluid discharged therefrom is always in a liquid form; and   said pump and said expander are so sized and designed that the high pressure portion of said vapor expansion circuit is always super-critical.   
     
     
         25 . A power generation vapor expansion circuit as set forth in  claim 24  wherein said refrigerant is CO 2 . 
     
     
         26 . A thermally activated cooling system as set forth in  claim 24  where said common refrigerant is a mixture of CO 2  and propane. 
     
     
         27 . A power generation vapor expansion circuit as set forth in  claim 24  and including a topping heat exchanger for causing heat to flow from the expander discharge stream to the stream flowing to the heater. 
     
     
         28 . A power generation vapor expansion circuit as set forth in  claim 24  wherein said expander is a two stage expander and further wherein a second heater is provided between the two stages. 
     
     
         29 . A power generation vapor expansion circuit as set forth in  claim 24  and including a second heater connected in serial flow relationship with said heater. 
     
     
         30 . A power generation vapor expansion circuit as set forth in  claim 24  wherein said power generator, said expander, and said pump have a common shaft. 
     
     
         31 . A power generation vapor expansion circuit as set forth in  claim 24  wherein said power generator, said expander, and said pump have a common hermetic casing. 
     
     
         32 . A power generation vapor expansion circuit as set forth in  claim 24  wherein said power generator powers a refrigerating system.