Co2 refrigeration system for ice-playing surfaces

Abstract

A CO 2 refrigeration system comprises a condensation reservoir. CO 2 refrigerant is accumulated in the reservoir. The CO 2 refrigerant circulates between supra-compression and evaporation loops. The supracompression loop comprises a compression stage for compression CO 2 refrigerant to a supracompression state, a cooling stage in which CO 2 refrigerant releases heat, and a pressure-regulating unit in a line extending from the cooling stage to the condensation reservoir. The pressure-regulating unit maintains a pressure differential between the cooling stage and the condensation reservoir. The evaporation loop comprises an evaporation stage in which CO 2 refrigerant from the condensation reservoir absorbs heat in a heat exchanger. The heat exchanger is connected to an ice-playing surface refrigeration circuit. A second refrigerant cycles in the ice-playing surface refrigeration circuit. The CO 2 refrigerant absorbs heat from the second refrigerant in the heat exchanger. A CO 2 condensation exchanger is also provided.

1 . A CO 2  refrigeration system for an ice-playing surface, comprising:
 a CO 2  refrigerant circuit in which CO 2  refrigerant circulates and having at least
 a compression stage in which CO 2  refrigerant is compressed and an evaporation stage in which heat is absorbed from an ice-playing surface, 
 a plurality of CO 2  compressors in the compression stage for compressing CO 2  refrigerant subcritically and transcritically, 
 a gas cooling stage comprising at least a plurality of heat-reclaim units reclaiming heat from the CO 2  refrigerant compressed in the compression stage, 
 a pressure-regulating device downstream of the gas cooling stage, the pressure-regulating device operable to control a pressure of the CO 2  refrigerant in the gas cooling stage as a function of a heat demand of the plurality of heat-reclaim units, 
 a reservoir downstream of the pressure-regulating device for receiving CO 2  refrigerant in a liquid state, and 
 an evaporation side of at least one heat exchanger downstream of the reservoir for the CO 2  refrigerant to absorb heat; and 
   a second refrigerant circuit in which a second refrigerant circulates and having at least
 a condensation side of the at least one heat exchanger for the second refrigerant to release heat to the CO 2  refrigerant in the evaporation side, and 
 piping in a floor of an ice-playing surface in which the second refrigerant refrigerates the ice-playing surface. 
   
     
     
         2 . The CO 2  refrigeration system according to  claim 1 , wherein the gas cooling stage further comprises at least one of a gas-cooling unit and a heat-reclaim exchanger. 
     
     
         3 . The CO 2  refrigeration system according to  claim 1 , comprising valves provided in relation to the plurality of heat-reclaim units to individually control a feed of CO 2  refrigerant directed to each said heat-reclaim unit. 
     
     
         4 . The CO 2  refrigeration system according to  claim 1 , wherein a fan of each said heat-reclaim unit is actuated as a function of a temperature demand. 
     
     
         5 . The CO 2  refrigeration system according to  claim 1 , further comprising at least one pump in the second refrigerant circuit to induce a flow of the second refrigerant therein. 
     
     
         6 . The CO 2  refrigeration system according to  claim 1 , further comprising a line extending from the evaporation side of the at least one heat exchanger to the compression stage, to direct the CO 2  refrigerant exiting the evaporation side thereat. 
     
     
         7 . The CO 2  refrigeration system according to  claim 1 , wherein a portion of the heat-reclaim units are in a parallel arrangement. 
     
     
         8 . The CO 2  refrigeration system according to  claim 1 , wherein a portion of the heat-reclaim units are in a series arrangement. 
     
     
         9 . The CO 2  refrigeration system according to  claim 1 , further comprising at least one expansion valve upstream of said piping to vaporize the second refrigerant fed to the piping. 
     
     
         10 . The CO 2  refrigeration system according to  claim 1 , further comprising at least one pump downstream of the reservoir to direct liquid CO 2  refrigerant to the evaporation side of the at least one heat exchanger. 
     
     
         11 . The CO 2  refrigeration system according to  claim 1 , wherein the second refrigerant is one of glycol and brine.