Transcritical R-744 refrigeration system for supermarkets with improved efficiency and reliability
A transcritical R-744 refrigeration system comprising at least one first compressor for compressing an R-744 refrigerant, a gas cooler for cooling the R-744 refrigerant compressed by the at least one first compressor, a throttling device for decreasing the pressure of the cooled R-744 refrigerant, a receiver for separating the R-744 refrigerant, a first heat exchanger for exchanging heat between the cooled R-744 refrigerant and the R-744 vapors separated by the receiver before the R-744 vapors are transported to the at least one first compressor, and an integrated R-744 refrigerant-based air-conditioning assembly comprising a second plurality of compressors and an air conditioner comprising a second heat exchanger and an evaporator, wherein the system is operatable in a dehumidification mode wherein the R-744 vapors exiting the gas cooler are fed through the second heat exchanger to heat and dehumidify the passing ambient air before being fed to the receiver.
1. A transcritical R-744 refrigeration system ( 80 ), the system ( 80 ) comprising:
at least one first compressor ( 1 ) for compressing an R-744 refrigerant from at least one first evaporator ( 30 );
a gas cooler ( 3 ) for cooling said R-744 refrigerant compressed by said at least one first compressor ( 1 );
a throttling device ( 27 ) connecting to said gas cooler ( 3 ) and decreasing a pressure of said R-744 refrigerant cooled by said gas cooler ( 3 );
a receiver ( 4 ) for separating said R-744 refrigerant into liquid R-744 and R-744 vapors, said receiver ( 4 ) feeding said at least one first evaporator ( 30 ) with said liquid R-744;
a first heat exchanger ( 21 ) for exchanging heat between said R-744 refrigerant cooled by said gas cooler ( 3 ) and said R-744 vapors separated by said receiver ( 4 ) before said R-744 vapors are transported to said at least one first compressor ( 1 ) through said at least one first evaporator ( 30 ); and
an air-conditioning assembly ( 90 ) being integrated with the system ( 80 ) and comprising an air conditioner ( 5 ) including a second heat exchanger ( 7 ) and a second evaporator ( 8 ), and at least one second compressor ( 2 ) for compressing said R-744 refrigerant from said second evaporator ( 8 );
wherein the system ( 80 ) is operatable in a dehumidification mode wherein said R-744 vapors exiting said gas cooler ( 3 ) are fed through said second heat exchanger ( 7 ) to heat and dehumidify ambient air passing through said second heat exchanger ( 7 ) before being fed to said receiver ( 4 ).
2. The transcritical R-744 refrigeration system ( 80 ) of claim 1 , wherein the system ( 80 ) is operatable in a heat reclaim mode wherein said R-744 vapors compressed by said at least one first compressor ( 1 ) are fed to a third heat exchanger ( 35 ) to evaporate said liquid R-744 from said receiver ( 4 ) before being fed to said gas cooler ( 3 ), said evaporated liquid R-744 being fed to and compressed by said at least one second compressor ( 2 ) before being fed to said second heat exchanger ( 7 ) to heat said ambient air passing through said second heat exchanger ( 7 ) and then to said gas cooler ( 3 ).
3. The transcritical R-744 refrigeration system ( 80 ) of claim 1 , wherein the system ( 80 ) is operatable in an air conditioning mode wherein said liquid R-744 from said receiver ( 4 ) is fed through said second evaporator ( 8 ) to cool ambient air passing through said second evaporator ( 8 ) before being fed through and compressed by said at least one second compressor ( 2 ) and then fed to said gas cooler ( 3 ).
4. The transcritical R-744 refrigeration system ( 80 ) of claim 1 , further comprising at least one bypass valve ( 23 , 24 ) for controlling the flow of said vapors flowing through said first heat exchanger 1211 to achieve a desired inlet temperature at said at least one first compressor ( 1 ).
5. The transcritical R-744 refrigeration system ( 80 ) of claim 1 , further comprising a pressure regulating valve ( 28 ) for regulating the pressure of said R-744 vapors after passing through said receiver ( 4 ).
6. The transcritical R-744 refrigeration system ( 80 ) of claim 5 , wherein said pressure regulating valve ( 28 ) is a flash gas bypass valve.
7. The transcritical R-744 refrigeration system ( 80 ) of claim 1 , further comprising a modulating valve ( 12 ) for modulating a flow of said R-744 vapors compressed by said at least one first compressor ( 1 ) and being fed to a third heat exchanger ( 35 ).
8. The transcritical R-744 refrigeration system ( 80 ) of claim 1 , wherein the system ( 80 ) is operatable in a heat reclaim mode wherein said R-744 vapors compressed by said at least one first compressor ( 1 ) are fed to said second heat exchanger ( 7 ) to heat passing ambient air and then fed to said gas cooler ( 3 ).
9. The transcritical R-744 refrigeration system ( 80 ) of claim 1 , wherein the air-conditioning assembly ( 90 ) is external to the system ( 80 ) and wherein the system ( 80 ) is operatable in an air conditioning mode wherein said second refrigerant from said external air-conditioning assembly is fed through said evaporator ( 8 ) to cool said passing ambient air.