Micro Booster Supermarket Refrigeration Architecture

Abstract

A refrigeration system includes first and second compressors, a condenser, first and second evaporators, and a valve. The first compressor is fluidly connected to first suction and discharge lines. The second compressor is fluidly connected to second suction and discharge lines. The second suction line is fluidly connected to the first discharge line. The condenser receives refrigerant from the second compressor. The first evaporator receives refrigerant from the condenser and discharges refrigerant to the first suction line. The second evaporator receives refrigerant from the condenser and discharges refrigerant to the second suction line. The valve is disposed between the first evaporator and the first suction line. The first suction line receives refrigerant when the valve is in a first position. The second suction line receives refrigerant when the valve is in a second position. The first compressor is bypassed when the valve is in the second position.

What is claimed is: 
     
         1 . A refrigeration system comprising:
 a first refrigeration loop comprising:
 at least one first compressor fluidly connected to a first suction line and a first discharge line; 
 at least one second compressor fluidly connected to a second suction line and a second discharge line, the second suction line being fluidly connected to the first discharge line; 
 a condenser operable to receive a first refrigerant from the at least one second compressor; 
 a first evaporator operable to receive the first refrigerant from the condenser and discharge the first refrigerant to the first suction line; 
 a second evaporator operable to receive the first refrigerant from the condenser and discharge the first refrigerant to the second suction line; 
 a heat exchanger operable to receive the first refrigerant from the condenser and discharge the first refrigerant to the second suction line; and 
 a bypass valve disposed between the first evaporator and the first suction line, wherein:
 the first suction line receives the first refrigerant from the first evaporator when the bypass valve is in a first position; 
 second suction line receives the first refrigerant from the first evaporator when the bypass valve is in a second position; and 
 the at least one first compressor is bypassed when the bypass valve is in the second position; and 
 
   a second refrigeration loop comprising:
 at least one third compressor; 
 the heat exchanger operable to receive a second refrigerant from the at least one third compressor; and 
 a third evaporator operable to receive the second refrigerant from the heat exchanger and discharge the second refrigerant to the at least one third compressor. 
   
     
     
         2 . The refrigeration system of  claim 1 , further comprising:
 a first refrigeration case operable to be cooled by the first evaporator within a first temperature range when the bypass valve is in a first position and within a second temperature range when the bypass valve is in the second position, the first temperature range being lower than the second temperature range; and   a second refrigeration case operable to be cooled by the second evaporator within the second temperature range.   
     
     
         3 . The refrigeration system of  claim 2 , further comprising:
 a third refrigeration case operable to be cooled by the third evaporator within the first temperature range.   
     
     
         4 . The refrigeration system of  claim 2 , further comprising:
 an expansion valve operable to receive the first refrigerant from the condenser and discharge the first refrigerant to the first evaporator.   
     
     
         5 . The refrigeration system of  claim 4 , further comprising:
 a controller adapted to:
 cool the first refrigeration case within the first temperature range by adjusting the expansion valve, operating the at least one first compressor, and moving the bypass valve to the first position; and 
 cool the first refrigeration case within the second temperature range by adjusting the expansion valve, stopping operation of the at least one first compressor, and moving the bypass valve to the second position. 
   
     
     
         6 . The refrigeration system of  claim 2 , further comprising:
 a first evaporator pressure regulator (EPR) valve downstream of the first evaporator, the first EPR valve being operable to be bypassed when the first refrigeration case is cooled within the first temperature range; and   a second EPR valve downstream of the second evaporator.   
     
     
         7 . The refrigeration system of  claim 3 , wherein the first refrigeration case, the second refrigeration case, the third refrigeration case, the at least one first compressor, and the at least one third compressor are disposed within a retail space. 
     
     
         8 . The refrigeration system of  claim 7 , wherein the at least one second compressor is disposed outside of the retail space. 
     
     
         9 . The refrigeration system of  claim 1 , wherein:
 the at least one first compressor is adapted to operate at a first compression ratio; and   the at least one second compressor is adapted to operate at a second compression ratio greater than the first compression ratio.   
     
     
         10 . The refrigeration system of  claim 9 , wherein the first compression ratio is in a range of 2-3. 
     
     
         11 . The refrigeration system of  claim 1 , further comprising:
 a defrost line between an inlet of the first evaporator and the first discharge line.   
     
     
         12 . The refrigeration system of  claim 1 , wherein the heat exchanger is adapted to at least partially transfer a condensing heat of the second refrigeration loop from the second refrigerant to the first refrigerant. 
     
     
         13 . The refrigeration system of  claim 12 , wherein the first refrigerant has a GWP of less than or equal to 1500. 
     
     
         14 . The refrigeration system of  claim 13 , wherein the first refrigerant has a GWP of less than or equal to 600. 
     
     
         15 . The refrigeration system of  claim 12 , wherein the first refrigerant is selected from a group consisting of R-134a, R-450A, R-513A, and R-515A. 
     
     
         16 . The refrigeration system of  claim 12 , wherein the first refrigerant and the second refrigerant are distinct and the second refrigerant has a lower global warming potential (GWP) than the first refrigerant. 
     
     
         17 . The refrigeration system of  claim 16 , wherein the second refrigerant comprises a hydrocarbon or an A2L refrigerant. 
     
     
         18 . The refrigeration system of  claim 12 , wherein the first refrigerant and the second refrigerant are the same. 
     
     
         19 . The refrigeration system of  claim 1 , wherein the at least one first compressor is a scroll compressor. 
     
     
         20 . The refrigeration system of  claim 1 , wherein the at least one first compressor is a variable-capacity compressor.