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 supracompression 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 comprising a CO 2  condensation reservoir in which CO 2  refrigerant is accumulated and circulates between a supracompression loop and an evaporation loop;
 the supracompression loop comprising a compression stage in which CO 2  refrigerant from at least the CO 2  condensation reservoir is compressed to at least a supracompression state, a cooling stage in which the CO 2  refrigerant from the compression stage releases heat, and a pressure-regulating unit in a line extending from the cooling stage to the CO 2  condensation reservoir to maintain a pressure differential therebetween; and   the evaporation loop comprising an evaporation stage in which the CO 2  refrigerant from at least the CO 2  condensation reservoir absorbs heat in a heat exchanger, the heat exchanger being connected to an ice-playing surface refrigeration circuit in which cycles a second refrigerant, such that the CO 2  refrigerant absorbs heat from the second refrigerant in the heat exchanger.   
     
     
         2 . The CO 2  refrigeration system according to  claim 2 , wherein the cooling stage comprises at least one of a gas-cooling unit, a heat-reclaim exchanger, and a heating unit. 
     
     
         3 . The CO 2  refrigeration system according to  claim 3 , comprising a plurality of the heating unit, with valves provided in relation to the plurality of heating unit to individually control an amount of CO 2  refrigerant directed to each said heating unit. 
     
     
         4 . The CO 2  refrigeration system according to  claim 3 , wherein a fan of each said heating unit is controlled by a controller as a function of a temperature demand and of said amount of amount of CO 2  refrigerant. 
     
     
         5 . The CO 2  refrigeration system according to  claim 1 , further comprising a relief system to relieve excess CO 2  refrigerant pressure in the CO 2  refrigeration system, the relief system comprising at least a pair of valves in parallel and opening to an exhaust, with a first of the valves being automatically operable from a first set point pressure to gradually release pressure, and a second one of the valves having a second set point pressure higher than the first set point pressure. 
     
     
         6 . The CO 2  refrigeration system according to  claim 1 , further comprising at least one pump in the evaporation loop to induce a flow of the CO 2  refrigerant therein. 
     
     
         7 . The CO 2  refrigeration system according to  claim 1 , further comprising a geothermal well loop in heat exchange relation with the evaporation loop, the geothermal well loop having a geothermal heat exchanger for heat exchange between the CO 2  refrigerant of the evaporation loop and another refrigerant absorbing heat from the CO 2  refrigerant of the evaporation loop, the geothermal well loop extending to a geothermal well in which the other refrigerant releases heat geothermally. 
     
     
         8 . The CO 2  refrigeration system according to  claim 1 , further comprising a line extending from the evaporation stage to at least one of the CO 2  condensation reservoir and the compression stage of the supracompression loop, to direct the CO 2  refrigerant exiting the evaporation stage thereat. 
     
     
         9 . The CO 2  refrigeration system according to  claim 1 , wherein the CO 2  refrigerant in the supracompression loop is compressed to a transcritical state. 
     
     
         10 . A CO 2  refrigeration system comprising a CO 2  condensation exchanger for heat exchange between a supracompression loop of CO 2  refrigerant and an evaporation loop of CO 2  refrigerant;
 the supracompression loop comprising a compression stage in which CO 2  refrigerant having absorbed heat in the condensation exchanger is compressed to at least a supracompression state, a cooling stage in which the CO 2  refrigerant from the compression stage releases heat, and a pressure-regulating unit in a line extending from the cooling stage to the condensation exchanger to maintain a pressure differential therebetween; and   the evaporation loop in which circulates CO 2  refrigerant having released heat in the condensation exchanger, the evaporation loop comprising a condensation reservoir in which CO2 refrigerant is accumulated in a liquid state, and an evaporation stage in which the CO 2  refrigerant from the condensation reservoir absorbs heat to cool an ice-playing surface, to then return to one of the condensation reservoir and the condensation exchanger.   
     
     
         11 . The CO 2  refrigeration system according to  claim 10 , wherein the evaporation stage of the evaporation loop comprises a heat exchanger being connected to an ice-playing surface refrigeration circuit in which cycles a second refrigerant, such that the CO 2  refrigerant absorbs heat from the second refrigerant in the heat exchanger. 
     
     
         12 . The CO 2  refrigeration system according to  claim 10 , wherein the evaporation stage of the evaporation loop comprises pipes under the ice-playing surface in which circulates the CO 2  refrigerant to refrigerate the ice-playing surface. 
     
     
         13 . The CO 2  refrigeration system according to  claim 12 , further comprising at least one pump in the evaporation loop to induce a flow of the CO 2  refrigerant in a liquid state in the pipes under the ice-playing surface. 
     
     
         14 . The CO 2  refrigeration system according to  claim 10 , wherein the cooling stage comprises at least one of a gas-cooling unit, a heat-reclaim exchanger, and a heating unit. 
     
     
         15 . The CO 2  refrigeration system according to  claim 14 , comprising a plurality of the heating unit, with valves provided in relation to the plurality of heating unit to individually control an amount of CO 2  refrigerant directed to each said heating unit. 
     
     
         16 . The CO 2  refrigeration system according to  claim 15 , wherein a fan of each said heating unit is controlled by a controller as a function of a temperature demand and of said amount of CO 2  refrigerant. 
     
     
         17 . The CO 2  refrigeration system according to  claim 10 , further comprising a relief system to relieve excess CO 2  refrigerant pressure in the CO 2  refrigeration system, the relief system comprising at least a pair of valves in parallel and opening to an exhaust, with a first of the valves being automatically operable from a first set point pressure to gradually release pressure, and a second one of the valves having a second set point pressure higher than the first set point pressure. 
     
     
         18 . The CO 2  refrigeration system according to  claim 10 , further comprising a geothermal well loop in heat-exchange relation with the evaporation loop, the geothermal well loop having a geothermal heat exchanger for heat exchange between the CO 2  refrigerant of the evaporation loop and another refrigerant absorbing heat from the CO 2  refrigerant of the evaporation loop, the geothermal well loop extending to a geothermal well in which the other refrigerant releases heat geothermally. 
     
     
         19 . The CO 2  refrigeration system according to  claim 10 , wherein the CO 2  refrigerant in the supracompression loop is compressed to a transcritical state. 
     
     
         20 . A CO 2  refrigeration system comprising a CO 2  condensation reservoir in which CO 2  refrigerant is accumulated and circulates between a supracompression loop and an evaporation loop;
 the supracompression loop comprising a compression stage in which CO 2  refrigerant from at least the CO 2  condensation reservoir is compressed to at least a supracompression state, a cooling stage in which the CO 2  refrigerant from the compression stage releases heat, and a pressure-regulating unit in a line extending from the cooling stage to the CO 2  condensation reservoir to maintain a pressure differential therebetween;   the evaporation loop comprising an evaporation stage of pipes under an ice-playing surface in which circulates the CO 2  refrigerant to absorb heat to cool an ice-playing surface, to then return to the CO 2  condensation reservoir; and   a geothermal well loop in heat-exchange relation with the CO 2  refrigerant, the geothermal well loop having a geothermal heat exchanger for heat exchange between the CO 2  refrigerant of one of the evaporation loop and the supracompression loop and another refrigerant absorbing heat from the CO 2  refrigerant, the geothermal well loop extending to a geothermal well in which the other refrigerant releases heat geothermally.