Refrigeration heat pump unit

Abstract

This application provides a refrigeration heat pump unit, including a refrigerant circuit formed by a centrifugal compressor, a condenser, a throttling device, and an evaporator. The centrifugal compressor includes a housing, a first motor, a second motor, a first compression chamber, a second compression chamber, a first impeller, a second impeller, and a controller. The controller is configured to turn on the first motor and turn off the second motor in response to a first working condition, turn off the first motor and turn on the second motor in response to a second working condition, and turn on the first motor and the second motor in response to a third working condition.

1 . A refrigeration heat pump unit, wherein the refrigeration heat pump unit comprises:
 a refrigerant circuit formed by a centrifugal compressor, a condenser, a throttling device, and an evaporator, wherein the centrifugal compressor includes:
 a housing; 
 a first motor disposed inside the housing; 
 a second motor disposed inside the housing and disposed opposite to the first motor; and 
   the refrigeration heat pump unit further comprises a controller,   the controller being configured to turn on the first motor and turn off the second motor in response to a first working condition, turn off the first motor and turn on the second motor in response to a second working condition, and turn on the first motor and the second motor in response to a third working condition.   
     
     
         2 . The refrigeration heat pump unit according to  claim 1 , wherein the centrifugal compressor further includes:
 a first compression chamber disposed at an end portion of the housing close to the first motor and including a first suction port and a first discharge port, the first suction port communicating with an outlet of the evaporator;   a second compression chamber disposed at an end portion of the housing close to the second motor and including a second suction port and a second discharge port, the second suction port communicating with the first discharge port, and the second discharge port communicating with an inlet of the condenser;   a first impeller disposed inside the first compression chamber and driven by the first motor; and   a second impeller disposed inside the second compression chamber and driven by the second motor.   
     
     
         3 . The refrigeration heat pump unit according to  claim 2 , wherein there are at least two first impellers and/or at least two second impellers. 
     
     
         4 . The refrigeration heat pump unit according to  claim 1 , wherein a rotation speed of the first motor and a rotation speed of the second motor are able to be controlled independently of each other. 
     
     
         5 . The refrigeration heat pump unit according to  claim 2 , wherein the first motor and the second motor are coaxially disposed, the first impeller is directly fixed to an output shaft of the first motor, and the second impeller is directly fixed to an output shaft of the second motor. 
     
     
         6 . The refrigeration heat pump unit according to  claim 2 , wherein the centrifugal compressor further includes:
 a first bypass flow path located between the first suction port and the first discharge port and bypassing the first impeller; and   a second bypass flow path located between the second suction port and the second discharge port and bypassing the second impeller.   
     
     
         7 . The refrigeration heat pump unit according to  claim 6 , wherein the centrifugal compressor further includes:
 a first switching device selectively communicating with the first bypass flow path or communicating with a compression flow path, the compression flow path being located between the first suction port and the first discharge port and passing through the first impeller; and   a second switching device selectively communicating with the second bypass flow path or communicating with a compression flow path, the compression flow path being located between the second suction port and the second discharge port and passing through the second impeller.   
     
     
         8 . The refrigeration heat pump unit according to  claim 5 , wherein the controller is configured to:
 turn on the first motor and turn off the second motor in response to the first working condition, causing the first switching device to selectively communicate with the compression flow path, the compression flow path being located between the first suction port and the first discharge port and passing through the first impeller, and causing the second switching device to selectively communicate with the second bypass flow path.   
     
     
         9 . The refrigeration heat pump unit according to  claim 5 , wherein the controller is configured to:
 turn off the first motor and turn on the second motor in response to the second working condition, causing the first switching device to selectively communicate with the first bypass flow path, and causing the second switching device to selectively communicate with the compression flow path, the compression flow path being located between the second suction port and the second discharge port and passing through the second impeller.   
     
     
         10 . The refrigeration heat pump unit according to  claim 5 , wherein the controller is configured to:
 turn on the first motor and the second motor in response to the third working condition, causing the first switching device to selectively communicate with the compression flow path, the compression flow path being located between the first suction port and the first discharge port and passing through the first impeller, and causing the second switching device to selectively communicate with the compression flow path, the compression flow path being located between the second suction port and the second discharge port and passing through the second impeller.   
     
     
         11 . The refrigeration heat pump unit according to  claim 5 , wherein
 the first switching device includes a first bypass valve and a first variable guide vane, the first bypass valve being disposed in the first bypass flow path, and the first variable guide vane being disposed corresponding to the first suction port, and   the second switching device includes a second bypass valve and a second variable guide vane, the second bypass valve being disposed in the second bypass flow path, and the second variable guide vane being disposed corresponding to the second suction port.   
     
     
         12 . The refrigeration heat pump unit according to  claim 11 , wherein
 the first bypass valve is a one-way valve that allows unidirectional flow from the first suction port to the first discharge port, and   the second bypass valve is a one-way valve that allows unidirectional flow from the second suction port to the second discharge port.   
     
     
         13 . The refrigeration heat pump unit according to  claim 11 , wherein the controller is configured to:
 turn on the first motor and turn off the second motor, and open the first variable guide vane and close the second variable guide vane in response to the first working condition;   turn off the first motor and turn on the second motor, and close the first variable guide vane and open the second variable guide vane in response to the second working condition; and   turn on the first motor and the second motor, and open the first variable guide vane and the second variable guide vane in response to the third working condition.