Multi-Circuit Refrigerant System Using Distinct Refrigerants

Abstract

A multi-circuit refrigerant system includes a plurality of circuits that are provided with distinct refrigerants. A control selectively matches a sensed environmental space conditioning challenge to selectively engage the plurality of circuits.

1 . A refrigerant system comprising:
 a plurality of parallel circuits, with each of said circuits including a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger; and   at least two distinct refrigerants used in a plurality of said circuits.   
   
   
       2 . The refrigerant system as set forth in  claim 1 , wherein there are two distinct refrigerants 
   
   
       3 . The refrigerant system as set forth in  claim 1 , wherein there are two parallel circuits 
   
   
       4 . The refrigerant system as set forth in  claim 1 , wherein each circuit operation is controlled by a controller to achieve a desired system operation. 
   
   
       5 . The refrigerant system as set forth in  claim 4 , wherein said controller selects an actuation order of said plurality of circuits. 
   
   
       6 . The refrigerant system as set forth in  claim 4 , wherein said controller selects an amount of engagement time for each circuit from a plurality of circuits. 
   
   
       7 . The refrigerant system as set forth in  claim 1 , wherein said distinct refrigerants include a first refrigerant that is best suited for lower ambient conditions and a second refrigerant that is best suited for higher ambient conditions, and a control sensing an ambient temperature, and actuating said plurality of circuits based upon said sensed ambient temperature, and an identification of a circuit which is charged with the refrigerant best matched to said sensed ambient temperature. 
   
   
       8 . The refrigerant system as set forth in  claim 7 , wherein said distinct refrigerants also include the first refrigerant best suited for higher temperature range for an environment to be conditioned and the second refrigerant that is best suited for lower temperature range for an environment to be conditioned, and the control using a demanded temperature range for actuating said plurality of circuits based upon said sensed demanded temperature range, and an identification of a circuit that is charged with the refrigerant best matched to said demanded temperature range. 
   
   
       9 . The refrigerant system as set forth in  claim 7 , wherein a plurality of circuits may be actuated, with said identified circuit actuated prior to the actuation of any other of said plurality of circuits. 
   
   
       10 . The refrigerant system as set forth in  claim 1 , wherein said distinct refrigerants include the first refrigerant best suited for higher temperature range for an environment to be conditioned and the second refrigerant that is best suited for lower temperature range for an environment to be conditioned, and the control using a demanded temperature range for actuating said plurality of circuits based upon said demanded temperature range, and an identification of a circuit that is charged with the refrigerant best matched to said demanded temperature range. 
   
   
       11 . The refrigerant system as set forth in  claim 10 , wherein a plurality of circuits may be actuated, with said identified circuit actuated prior to the actuation of any other of said plurality of circuits. 
   
   
       12 . The refrigerant system as set forth in  claim 1 , wherein a plurality of circuits may be actuated, with an identified circuit actuated prior to the actuation of any other of said plurality of circuits. 
   
   
       13 . The refrigerant system as set forth in  claim 1 , wherein the system is operating in a cooling mode. 
   
   
       14 . The refrigerant system as set forth in  claim 1 , wherein the system is operating in a heating mode. 
   
   
       15 . The refrigerant system as set forth in  claim 1 , wherein said refrigerant system is operable as a heat pump, and includes a flow control device for selectively routing refrigerant from said compressor to said outdoor heat exchanger initially in a cooling mode, or initially to said indoor heat exchanger when in a heating mode, and said plurality of refrigerants include a first refrigerant that is best utilized in a refrigerant system in a cooling mode, and a second refrigerant which is best utilized in a refrigerant system in a heating mode, said control changes said circuit actuation order dependent upon whether the refrigerant system is in cooling mode or heating mode. 
   
   
       16 . The refrigerant system as set forth in  claim 1 , wherein said refrigerant system is operable as a heat pump, and includes a flow control device for selectively routing refrigerant from said compressor to said outdoor heat exchanger initially in a cooling mode, or initially to said indoor heat exchanger when in a heating mode, and said plurality of refrigerants includes a first refrigerant that is best utilized in a refrigerant system in a cooling mode, and a second refrigerant that is best utilized in a refrigerant system in a heating mode, said control actuating both circuits based on cooling and dehumidification demands. 
   
   
       17 . The refrigerant system as set forth in  claim 1 , wherein the first and second refrigerants are selected to provide distinct capacities at different environmental conditions, and said control sensing the environmental conditions, and utilizing the two circuits in an order to achieve a desired capacity at the sensed environmental conditions. 
   
   
       18 . The refrigerant system as set forth in  claim 1 , wherein said distinct refrigerants are selected from single component refrigerants and multiple component refrigerant mixtures. 
   
   
       19 . The refrigerant system as set forth in  claim 1 , wherein said distinct refrigerants are mixtures consisting of the same components, but with different compositions. 
   
   
       20 . A method of operating a multi-circuit refrigerant system comprising the steps of:
 (1) providing a plurality of refrigerant circuits operating in parallel, a common control for said plurality of refrigerant circuits and providing distinct refrigerants in a plurality of said refrigerant circuits; and   (2) selectively operating said plurality of circuits for desired system operation.   
   
   
       21 . The method as set forth in  claim 20 , wherein said distinct refrigerants include a first refrigerant that is best suited for lower ambient conditions and a second refrigerant that is best suited for higher ambient conditions, and a control sensing an ambient temperature, and actuating said plurality of circuits based upon said sensed ambient temperature, and an identification of a circuit which includes the refrigerant best matched to said sensed ambient temperature. 
   
   
       22 . The method as set forth in  claim 21 , wherein said distinct refrigerants also include the first refrigerant best suited for higher temperature range for an environment to be conditioned and the second refrigerant that is best suited for lower temperature range for an environment to be conditioned, and the control using a demanded temperature range for actuating said plurality of circuits based upon said sensed demanded temperature range, and an identification of a circuit that is charged with the refrigerant best matched to said demanded temperature range. 
   
   
       23 . The method as set forth in  claim 22 , wherein a plurality of circuits may be actuated, with said identified circuit actuated prior to the actuation of any other of said plurality of circuits. 
   
   
       24 . The method as set forth in  claim 21 , wherein a plurality of circuits may be actuated, with said identified circuit actuated for a majority of time as compared to any other of said plurality of circuits. 
   
   
       25 . The method as set forth in  claim 20 , wherein said distinct refrigerants include the first refrigerant best suited for higher temperature range for an environment to be conditioned and the second refrigerant that is best suited for lower temperature range for an environment to be conditioned, and the control using a demanded temperature range for actuating said plurality of circuits based upon said sensed demanded temperature range, and an identification of a circuit that is charged with the refrigerant best matched to said demanded temperature range. 
   
   
       26 . The method as set forth in  claim 25 , wherein a plurality of circuits may be actuated, with said identified circuit actuated prior to the actuation of any other of said plurality of circuits. 
   
   
       27 . The method as set forth in  claim 25 , wherein a plurality of circuits may be actuated, with said identified circuit actuated for majority of the time as compared to any other of said plurality of circuits. 
   
   
       28 . The method as set forth in  claim 20 , wherein a plurality of circuits may be actuated, with an identified circuit actuated prior to the actuation of any other of said plurality of circuits. 
   
   
       29 . The method as set forth in  claim 20 , wherein a plurality of circuits may be actuated with an identified circuit actuated for majority of the time as compared to any other of said plurality of circuits. 
   
   
       30 . The method as set forth in  claim 20 , wherein said refrigerant system is operable as a heat pump, and includes a flow control device for selectively routing refrigerant from said compressor to said outdoor heat exchanger initially in a cooling mode, or initially to said indoor heat exchanger when in a heating mode, and said plurality of refrigerants includes a first refrigerant that is best utilized in a refrigerant system in a cooling mode, and a second refrigerant that is best utilized in a refrigerant system in a heating mode, said control actuating both circuits based on cooling and dehumidification demands. 
   
   
       31 . The method as set forth in  claim 20 , wherein the first and second refrigerants are selected to provide distinct capacities at different environmental conditions, and said control sensing the environmental conditions, and selectively operating said plurality of circuits to achieve a desired capacity at the sensed environmental conditions. 
   
   
       32 . The method as set forth in  claim 20 , wherein the system is operating in a cooling mode. 
   
   
       33 . The method as set forth in  claim 20 , wherein the system is operating in a heating mode. 
   
   
       34 . The method as set forth in  claim 20 , wherein said refrigerant system is operable as a heat pump, and includes a flow control device for selectively routing refrigerant from said compressor to said outdoor heat exchanger initially in a cooling mode, or initially to said indoor heat exchanger when in a heating mode, and said plurality of refrigerants include a first refrigerant that is best utilized in a refrigerant system in a cooling mode, and a second refrigerant which is best utilized when in a refrigerant system in a heating mode.