Secondary refrigeration circuit including micro-encapsulated phase change material

Abstract

A refrigeration system including a primary circuit that has a compressor circulating a first heat exchange fluid and a heat exchanger located downstream of the compressor. The refrigeration system also includes a secondary circuit circulating a second heat exchange fluid that has micro-encapsulated phase change material in heat exchange relationship with the primary circuit via the heat exchanger. A refrigerated display case defines a product display area and has an airflow in heat exchange relationship with the primary circuit or the secondary circuit.

1 . A refrigeration system comprising:
 a primary circuit including a compressor circulating a first heat exchange fluid and a heat exchanger located downstream of the compressor;   a secondary circuit circulating a second heat exchange fluid having micro-encapsulated phase change material in heat exchange relationship with the primary circuit via the heat exchanger; and   a refrigerated display case defining a product display area and having an airflow in heat exchange relationship with the primary circuit or the secondary circuit.   
     
     
         2 . The refrigeration system of  claim 1 , wherein the secondary circuit includes a pump and the second heat exchange fluid includes a single phase coolant. 
     
     
         3 . The refrigeration system of  claim 2 , wherein the second heat exchange fluid includes a mixture of propylene glycol and water. 
     
     
         4 . The refrigeration system of  claim 2 , wherein the second heat exchange fluid includes hydrofluoroether. 
     
     
         5 . The refrigeration system of  claim 2 , wherein the secondary circuit includes an air-cooled heat exchanger and the refrigeration system includes a plurality of refrigerated display cases, and wherein each of the refrigerated display cases is in heat exchange relationship with the secondary circuit via a corresponding discrete heat exchanger. 
     
     
         6 . The refrigeration system of  claim 2 , wherein the primary circuit includes the heat exchanger, a compressor, and a condenser fluidly connected and arranged in series with each other, and wherein the secondary circuit includes the pump, the heat exchanger, and the refrigerated display case fluidly connected and arranged in series with each other. 
     
     
         7 . The refrigeration system of  claim 1 , wherein the second heat exchange fluid includes a non-zero quantity of up to 50% by mass of the micro-encapsulated phase change material. 
     
     
         8 . The refrigeration system of  claim 7 , wherein the second heat exchange fluid includes between about 20% and about 30% by mass of the micro-encapsulated phase change material. 
     
     
         9 . The refrigeration system of  claim 1 , wherein the micro-encapsulated phase change material has a temperature phase change between −40° Fahrenheit and 300° Fahrenheit. 
     
     
         10 . A refrigeration system comprising:
 a primary circuit including a heat exchanger;   a first heat exchange fluid configured to circulate through the primary circuit;   a secondary circuit in fluid communication with the heat exchanger; and   a second heat exchange fluid configured to circulate through the secondary circuit and including a plurality of different micro-encapsulated phase change materials, each of the micro-encapsulated phase change materials changing phase at a different temperature.   
     
     
         11 . The refrigeration system of  claim 10 , wherein the second heat exchange fluid includes a single phase coolant having one of a mixture of propylene glycol and water, and hydrofluoroether. 
     
     
         12 . The refrigeration system of  claim 10 , wherein the secondary circuit includes an air-cooled heat exchanger and the refrigeration system includes a plurality of refrigerated display cases, and wherein each of the refrigerated display cases is in heat exchange relationship with the secondary circuit via a corresponding heat exchanger. 
     
     
         13 . The refrigeration system of  claim 10 , wherein the primary circuit includes the heat exchanger, a compressor, and a condenser fluidly connected and arranged in series with each other, and wherein the secondary circuit includes the heat exchanger, a refrigerated display case, and a pump fluidly connected and arranged in series with each other. 
     
     
         14 . The refrigeration system of  claim 10 , wherein the second heat exchange fluid includes a non-zero quantity of up to 50% by mass of the micro-encapsulated phase change materials. 
     
     
         15 . The refrigeration system of  claim 14 , wherein the second heat exchange fluid includes between about 20% and 30% by mass of the micro-encapsulated phase change materials. 
     
     
         16 . A refrigeration system comprising:
 a primary circuit circulating a first heat exchange fluid and including a first heat exchanger;   a plurality of refrigerated display cases each defining a product display area and including a second heat exchanger; and   a secondary circuit in fluid communication with the first heat exchanger and the second heat exchangers, the secondary circuit circulating a second heat exchange fluid between the first heat exchanger and the second heat exchangers and including a single phase coolant and a non-zero quantity of up to 50% by mass of a micro-encapsulated phase change material.   
     
     
         17 . The refrigeration system of  claim 16 , wherein the second fluid includes a mixture of propylene glycol and water. 
     
     
         18 . The refrigeration system of  claim 16 , wherein the second fluid includes hydrofluoroether. 
     
     
         19 . The refrigeration system of  claim 16 , wherein the second fluid includes between about 20% and about 30% by mass of the micro-encapsulated phase change materials. 
     
     
         20 . The refrigeration system of  claim 16 , wherein the second heat exchange fluid includes a plurality of micro-encapsulated phase change materials, and wherein each of the micro-encapsulated phase change materials changes phase at a different temperature.