Air conditioner

Abstract

An air conditioner is configured with a plurality of utilization units, such that an increase in the cost of parts constituting a refrigerant circuit is prevented even if the maximum working pressure of the refrigerant circuit increases. The air conditioner has a plurality of utilization units, a vapor compression type refrigerant circuit with an accumulator. The refrigerant circuit has a high pressure unit for handling a high-pressure refrigerant at a maximum working pressure of 3.3 MPa or higher, and a low pressure unit for handling only low-pressure refrigerant at a maximum working pressure of less than 3.3 MPa. The accumulator is one of the parts constituting the low pressure unit and is capable of pooling refrigerant circulating inside the refrigerant circuit as liquid refrigerant. The refrigerant that flows through the low pressure unit and the high pressure unit is preferably R410A.

1 . An air conditioner comprising: 
 a plurality of utilization units; and    a vapor compression type refrigerant circuit including a high pressure unit configured and arranged for flowing a high-pressure refrigerant at a maximum working pressure of 3.3 MPa or higher and a low pressure unit configured and arranged for flowing only a low-pressure refrigerant at a maximum working pressure of less than 3.3 MPa,    said low pressure unit including an accumulator being configured and arranged for pooling refrigerant that circulates inside said vapor compression type refrigerant circuit as a liquid refrigerant, and    said refrigerant that flows through said low pressure unit and said high pressure unit being one of a pseudo azeotropic refrigerant, an azeotropic refrigerant, and a single refrigerant having saturation pressure characteristics higher than R407C.    
     
     
         2 . An air conditioner comprising: 
 a compressor configured and arranged to compress low-pressure gas refrigerant and discharge high-pressure gas refrigerant, said compressor having an inlet side and a discharge side;    a heat source side heat exchanger configured and arranged to operate as at least one of an evaporator and a condenser, said heat source side heat exchanger having a gas side;    a plurality of utilization side heat exchangers mutually connected in parallel and having a gas side, each of the utilization side heat exchangers being configured and arranged to operate as at least one of a condenser and an evaporator;    expansion mechanisms connected between said utilization side heat exchangers and said heat source side heat exchanger;    a switching mechanism configured and arranged for switching between a state in which said gas side of said heat source side heat exchanger is connected to said discharge side of said compressor, said inlet side of said compressor is connected to said gas side of said utilization side heat exchangers and low-pressure gas refrigerant is sucked into said compressor, and a state in which said gas side of said heat source side heat exchanger is connected to said inlet side of said compressor, said discharge side of said compressor is connected to said gas side of said utilization side heat exchangers and high-pressure gas refrigerant flows to said utilization side heat exchangers; and    an accumulator connected between said switching mechanism and said inlet side of said compressor, said accumulator being configured and arranged for pooling low-pressure refrigerant as a liquid refrigerant,    said accumulator, said switching mechanism and said inlet side of said compressor forming a low pressure unit, which is configured and arranged for flowing only low-pressure refrigerant at a maximum working pressure of less than 3.3 MPa,    said compressor, said heat source side heat exchanger, said plurality of utilization side heat exchangers, and said switching mechanism forming a high pressure unit, which is configured and arranged for flowing high-pressure refrigerant at a maximum working pressure of 3.3 MPa or higher, and    said refrigerant that flows through said low pressure unit and said high pressure unit being one of a pseudo azeotropic refrigerant, an azeotropic refrigerant, and a single refrigerant having saturation pressure characteristics higher than R407C.    
     
     
         3 . The air conditioner as recited in  claim 2 , further comprising: 
 a heat source side temperature detector configured and arranged to detect a refrigerant temperature on a liquid side of said heat source side heat exchanger;    a utilization side temperature detector configured and arranged to detect a refrigerant temperature on a liquid side of each of said utilization side heat exchangers; and    a high pressure pressure detector configured and arranged to detect a refrigerant pressure on said discharge side of said compressor,    based on detected values of said refrigerant temperature and said refrigerant pressure detected by said heat source side temperature detector, said utilization side temperature detectors and said high pressure pressure detector, each of said expansion mechanisms having an opening that is regulated so that said liquid refrigerant on said liquid side of said heat source side heat exchanger reaches a prescribed subcooled state when said heat source side heat exchanger functions as a condenser, said opening of each said expansion mechanisms is regulated so that said liquid refrigerant on said liquid side of each said utilization side heat exchanger reaches a prescribed subcooled state when said utilization side heat exchanger functions as the condenser.    
     
     
         4 . The air conditioner as recited in  claim 1 , wherein 
 said refrigerant that flows through said low pressure unit and said high pressure unit includes R32.    
     
     
         5 . The air conditioner as recited in  claim 1 , wherein 
 said refrigerant that flows through said low pressure unit and said high pressure unit includes R410A.    
     
     
         6 . The air conditioner as recited in  claim 2 , wherein 
 said refrigerant that flows through said low pressure unit and said high pressure unit includes R32.    
     
     
         7 . The air conditioner as recited in  claim 3 , wherein 
 said refrigerant that flows through said low pressure unit and said high pressure unit includes R32.    
     
     
         8 . The air conditioner as recited in  claim 2 , wherein 
 said refrigerant that flows through said low pressure unit and said high pressure unit includes R410A.    
     
     
         9 . The air conditioner as recited in  claim 3 , wherein 
 said refrigerant that flows through said low pressure unit and said high pressure unit includes R410A.