Evaporatively cooled refrigeration system and method

Abstract

An evaporatively cooled refrigeration system includes a refrigerant, a gas/liquid separator, an expansion valve in fluid connection to the gas/liquid separator, an evaporator to receive the refrigerant from the expansion valve, a compressor configured to compress the refrigerant in fluid connection to the evaporator, and a gas cooler in fluid connection to the compressor. The gas cooler includes an indirect heat exchanger to convey the refrigerant and facilitate heat from the refrigerant and a spray system to spray an evaporative coolant on the indirect heat exchanger. Evaporative cooling provided by the evaporative coolant on the coil is configured to cool the refrigerant below a dry bulb ambient air temperature.

What is claimed is: 
     
         1 . A refrigeration system, comprising:
 a refrigerant;   a compressor configured to compress the refrigerant;   a gas cooler downstream of the compressor comprising:
 a first distribution system configured to provide an evaporative coolant to a direct heat exchanger, wherein the direct heat exchanger is configured to cool the evaporative coolant from a first temperature to a second temperature less than the first temperature; 
 an indirect heat exchanger configured to receive the cooled evaporative coolant from the direct heat exchanger, the indirect heat exchanger comprising a coil configured to cool the refrigerant below a dry bulb ambient air temperature by transferring heat from the refrigerant to the evaporative coolant; 
   an evaporator downstream of the gas cooler and upstream of the compressor; and   an expansion valve disposed in fluid connection downstream of the gas cooler and upstream of the evaporator.   
     
     
         2 . The refrigeration system of  claim 1 , wherein the refrigerant is carbon dioxide. 
     
     
         3 . The refrigeration system of  claim 1 , wherein the evaporative coolant is water. 
     
     
         4 . The refrigeration system of  claim 1 , further including a fan to generate a flow of air across the indirect heat exchanger. 
     
     
         5 . The refrigeration system of  claim 1 , further including a liquid/vapor separator disposed in fluid connection downstream of the multi-stage cooler and upstream of the evaporator. 
     
     
         6 . The refrigeration system of  claim 5 , further comprising a flash gas bypass valve disposed in fluid connection downstream of the liquid/vapor separator and upstream of the compressor. 
     
     
         7 . The refrigeration system of  claim 1 , further comprising a low temperature evaporator and a low temperature expansion valve, wherein the expansion valve and the evaporator are configured to provide a first amount of superheat and wherein the low temperature expansion valve and the low temperature evaporator are configured to provide a second amount of superheat. 
     
     
         8 . The refrigeration system of  claim 7 , further comprising a low temperature compressor disposed in fluid connection downstream of the low temperature evaporator and upstream of the compressor. 
     
     
         9 . The refrigeration system of  claim 1 , further comprising a throttling valve disposed in fluid connection downstream of the multi-stage cooler and upstream of the evaporator. 
     
     
         10 . A gas cooler, comprising:
 an indirect heat exchanger comprising a coil;   a distribution system for providing an evaporative coolant to the indirect heat exchanger,   wherein the indirect heat exchanger is configured to cool a refrigerant flowing through the coil below a dry bulb ambient air temperature by transferring heat from the refrigerant to the evaporative coolant provided to the indirect heat exchanger.   
     
     
         11 . The gas cooler of  claim 10 , wherein coils of the indirect heat exchanger are configured to withstand a pressure of at least  1000  pounds per square inch absolute (PSIA). 
     
     
         12 . The multi-stage cooler of  claim 10 , further comprising:
 a compressor configured to compress the refrigerant;   an evaporator disposed in fluid connection downstream of the gas cooler and upstream of the compressor; and   an expansion valve disposed in fluid connection downstream of the gas cooler and upstream of the evaporator.   
     
     
         13 . The gas cooler of  claim 10 , wherein the refrigerant is carbon dioxide. 
     
     
         14 . The multi-stage cooler of  claim 10 , wherein the evaporative coolant is water. 
     
     
         15 . The multi-stage cooler of  claim 10 , further including a fan to generate a flow of air across the indirect heat exchanger. 
     
     
         16 . The multi-stage cooler of  claim 10 , further including a direct heat exchanger configured to cool the evaporative coolant from a first temperature to a second temperature less than the first temperature prior to the evaporative coolant being provided to the indirect heat exchanger. 
     
     
         17 . The device according to  claim 12 , further including a liquid/vapor separator disposed in fluid connection downstream of the gas cooler and upstream of the evaporator. 
     
     
         18 . The device according to  claim 17 , further comprising a flash gas bypass valve disposed in fluid connection downstream of the liquid/vapor separator and upstream of the compressor. 
     
     
         19 . The device according to  claim 12 , further comprising a low temperature evaporator and a low temperature expansion valve, wherein the expansion valve and the evaporator are configured to provide a first amount of superheat and wherein the low temperature expansion valve and the low temperature evaporator are configured to provide a second amount of superheat. 
     
     
         20 . The device according to  claim 19 , further comprising a low temperature compressor disposed in fluid connection downstream of the low temperature evaporator and upstream of the compressor.