Centrifugal compressor, refrigeration heat pump unit

Abstract

This application provides a centrifugal compressor and a refrigeration heat pump unit, the centrifugal compressor includes a first compression chamber including a first inlet portion that includes a first variable guide vane, and a first outlet portion. A second compression chamber including a second inlet portion that includes a second variable guide vane, and a second outlet portion. A first impeller rotatably disposed inside the first compression chamber and disposed adjacent to the first variable guide vane. A second impeller rotatably disposed inside the second compression chamber and disposed adjacent to the second variable guide vane. A third impeller rotatably disposed inside the first compression chamber and located downstream of the first impeller. A first bypass pipe allowing a discharge flow passage of the third impeller to communicate with an inlet of the third impeller.

What is claimed is: 
     
         1 . A centrifugal compressor comprising:
 a first compression chamber including a first inlet portion that includes a first variable guide vane, and a first outlet portion;   a second compression chamber including a second inlet portion that includes a second variable guide vane, and a second outlet portion;   a first impeller rotatably disposed inside the first compression chamber;   a second impeller rotatably disposed inside the second compression chamber;   a third impeller rotatably disposed inside the first compression chamber; and   a first bypass pipe configured to allow a discharge flow passage of the third impeller to communicate with an inlet of the third impeller.   
     
     
         2 . The centrifugal compressor according to  claim 1 , further comprising:
 a motor configured to drive the first impeller, the second impeller and the third impeller, wherein the first compression chamber and the second compression chamber are disposed opposite to each other at two ends of the motor.   
     
     
         3 . The centrifugal compressor according to  claim 2 , wherein the motor includes a motor body and a motor shaft, the motor body is disposed between the first compression chamber and the second compression chamber, the motor shaft passes through the motor body and two ends thereof extend into the first compression chamber and the second compression chamber respectively, and the first impeller, the second impeller and the third impeller are all directly fixed to the motor shaft. 
     
     
         4 . The centrifugal compressor according to  claim 1 , wherein a communication member allows the first outlet portion to communicate with the second inlet portion, and
 the centrifugal compressor further comprises:   a second bypass pipe configured to allow a discharge flow passage of the second impeller to communicate with an inlet of the second impeller, or configured to allow the discharge flow passage of the second impeller to communicate with an inlet of the second variable guide vane.   
     
     
         5 . The centrifugal compressor according to  claim 1 , wherein a communication member allows the first outlet portion to communicate with the second inlet portion, and
 the centrifugal compressor further comprises:   a fourth impeller rotatably disposed inside the second compression chamber, located downstream of the second impeller, and disposed adjacent to the second outlet portion; and   a second bypass pipe configured to allow a discharge flow passage of the fourth impeller to communicate with an inlet of the fourth impeller.   
     
     
         6 . A refrigeration heat pump unit comprising a refrigerant circuit formed by a centrifugal compressor, a condenser, a throttling device, and an evaporator, wherein
 the centrifugal compressor includes:   a first compression chamber including a first inlet portion that includes a first variable guide vane and communicates with an outlet of the evaporator, and a first outlet portion;   a second compression chamber including a second inlet portion that includes a second variable guide vane and communicates with the first outlet portion, and a second outlet portion that communicates with an inlet of the condenser;   a first impeller rotatably disposed inside the first compression chamber and disposed adjacent to the first variable guide vane;   a second impeller rotatably disposed inside the second compression chamber and disposed adjacent to the second variable guide vane;   a third impeller rotatably disposed inside the first compression chamber and located downstream of the first impeller; and   a first bypass pipe configured to allow a discharge flow passage of the third impeller to communicate with an inlet of the third impeller.   
     
     
         7 . The refrigeration heat pump unit according to  claim 6 , wherein
 the centrifugal compressor further includes a motor configured to drive the first impeller, the second impeller and the third impeller, and   the first compression chamber and the second compression chamber are disposed opposite to each other at two ends of the motor.   
     
     
         8 . The refrigeration heat pump unit according to  claim 7 , wherein the centrifugal compressor further includes:
 a second bypass pipe configured to allow a discharge flow passage of the second impeller to communicate with an inlet of the second impeller, or configured to allow the discharge flow passage of the second impeller to communicate with an inlet of the second variable guide vane.   
     
     
         9 . The refrigeration heat pump unit according to  claim 6 , further comprising:
 a first economizer connected between the condenser and the evaporator;   a second economizer connected between the condenser and the evaporator, and connected in series with the first economizer;   a first pipe configured to allow an outlet of the first economizer to communicate with the inlet of the third impeller; and   a second pipe configured to allow an outlet of the second economizer to communicate with the discharge flow passage of the third impeller, wherein   two ends of the first bypass pipe are respectively connected to the first pipe and the second pipe.   
     
     
         10 . The refrigeration heat pump unit according to  claim 9 , further comprising:
 a control valve disposed on the first bypass pipe, wherein   the throttling device includes:   a first throttling device located between the condenser and the second economizer;   a second throttling device located between the second economizer and the first economizer; and   a third throttling device located between the first economizer and the evaporator.   
     
     
         11 . A refrigeration heat pump unit comprising a refrigerant circuit formed by a centrifugal compressor, a condenser, a throttling device, and an evaporator, wherein
 the centrifugal compressor includes:   a first compression chamber including a first inlet portion that includes a first variable guide vane, and a first outlet portion that communicates with an inlet of the condenser;   a second compression chamber including a second inlet portion that includes a second variable guide vane and communicates with an outlet of the evaporator, and a second outlet portion that communicates with the first inlet portion;   a first impeller rotatably disposed inside the first compression chamber and disposed adjacent to the first variable guide vane;   a second impeller rotatably disposed inside the second compression chamber and disposed adjacent to the second variable guide vane;   a third impeller rotatably disposed inside the first compression chamber and located downstream of the first impeller; and   a first bypass pipe configured to allow a discharge flow passage of the third impeller to communicate with an inlet of the third impeller.   
     
     
         12 . The centrifugal compressor according to  claim 1 , wherein a communication member is configured to allow the first outlet portion to communicate with the second inlet portion, or is configured to allow the second outlet portion to communicate with the first inlet portion. 
     
     
         13 . The centrifugal compressor according to  claim 1 , wherein the first impeller is disposed adjacent to the first variable guide vane. 
     
     
         14 . The centrifugal compressor according to  claim 1 , wherein the second impeller is disposed adjacent to the second variable guide vane. 
     
     
         15 . The centrifugal compressor according to  claim 1 , wherein the third impeller is located downstream of the first impeller.