Cascading Plant

Abstract

An integrated refrigeration and air conditioning plant working in a cascade cycle with two different refrigerants for the low and high temperature circuits. The low temperature segment works with an ozone friendly synthetic refrigerant with a minimal amount of refrigerant charge, while the upper stage operates with another ozone friendly refrigerant with much lesser global warming potential than the one in the low stage. The upper and/or medium temperature circuit also services the air conditioning needs of the environment where the refrigerated equipment is located, such as the shop floor of a supermarket or a laboratory housing the cabinets that keep refrigerators.

1 . A climate system for an enclosure, the enclosure having at least three sub-enclosures, the system comprising:
 (a) a refrigeration plant for maintaining the sub-enclosures within predetermined temperature ranges including,
 (i) a low temperature circuit for cooling at least one sub-enclosure; 
 (ii) a medium temperature circuit for cooling at least one sub-enclosure; and 
 (iii) a high temperature circuit for cooling at least one sub-enclosure; wherein the medium temperature circuit and/or high temperature circuit is in heat exchange with the low temperature circuit, 
 and 
   (b) an air conditioning plant for maintaining the enclosure, external of any sub enclosure, within at least one predetermined temperature range including at least one non refrigerant fluid circuit in heat exchange with (i) the medium temperature circuit and/or high temperature circuit and (ii) an air circulation circuit for the enclosure.   
     
     
         2 . The climate system of  claim 1  wherein the refrigerant in the low temperature circuit is a high rated global warming refrigerant and the refrigerant in the medium temperature circuit and/or high temperature circuit is a low rated global warming refrigerant. 
     
     
         3 . The climate system of  claim 1  wherein the refrigerant in the low temperature circuit is CO2 or ammonia and the refrigerant in the medium temperature circuit and/or high temperature circuit is a low rated global warming refrigerant. 
     
     
         4 . The climate system of  claim 1  wherein the refrigerant in the low temperature circuit is CO2 and the refrigerant in the medium temperature circuit and/or high temperature circuit is a high rated global warming refrigerant. 
     
     
         5 . The system of  claim 1 , comprising a first and a second non refrigerant fluid circuit, the first circuit for circulating chilled fluid for heat exchange with the air circulation circuit to cool air and the second circuit for circulating warm fluid for heat exchange with the air circulation circuit to warm air. 
     
     
         6 . The system of  claim 1  further comprising a control system for optimising the operation of the system. 
     
     
         7 . The system  claim 6  wherein the control system includes one or more sensors to sense perturbations in the operation of the system and one or more transmitters to generate signals to the low temperature circuit and/or medium temperature circuit and/or high temperature circuit in response to sensing said perturbations.