Refrigeration cycle device

Abstract

A refrigeration cycle device includes: a compressor having a compression mechanism forming a compression chamber for compressing refrigerant, and a cooled portion cooled by the refrigerant before being compressed by the compression mechanism; a radiator that radiates the refrigerant compressed by the compressor; a decompressor that decompresses the refrigerant radiated by the radiator; an evaporator that evaporates the refrigerant decompressed by the decompressor; an acquisition unit that acquires the state of the refrigerant after cooling the cooled portion and before flowing into the compression chamber; and a control unit that controls the superheat degree of the refrigerant flowing into the compression chamber based on the state of the refrigerant acquired by the acquisition unit.

What is claimed is: 
     
         1 . A refrigeration cycle device comprising:
 a compressor having a compression mechanism forming a compression chamber to compress a refrigerant, and a cooled portion cooled by the refrigerant before being compressed by the compression mechanism;   a radiator configured to radiate heat from the refrigerant compressed by the compressor;   an evaporator decompressor configured to decompress the refrigerant radiated by the radiator;   an evaporator configured to evaporate the refrigerant decompressed by the evaporator decompressor;   an acquisition unit configured to acquire a state of the refrigerant after cooling the cooled portion and before flowing into the compression chamber; and   a control unit configured to control a superheat degree of the refrigerant flowing into the compression chamber based on the state of the refrigerant acquired by the acquisition unit, wherein   the cooled portion is cooled by the refrigerant after being evaporated by the evaporator and before being compressed by the compression mechanism.   
     
     
         2 . The refrigeration cycle device according to  claim 1 , wherein the control unit controls the superheat degree by controlling the evaporator decompressor based on the state of the refrigerant acquired by the acquisition unit. 
     
     
         3 . The refrigeration cycle device according to  claim 1 , further comprising:
 a bypass unit that bypasses the evaporator decompressor and the evaporator to guide the refrigerant radiated by the radiator to the compressor; and   a bypass decompressor configured to decompress the refrigerant flowing through the bypass unit, wherein   the control unit controls the superheat degree by controlling the bypass decompressor based on the state of the refrigerant acquired by the acquisition unit.   
     
     
         4 . The refrigeration cycle device according to  claim 1 , further comprising:
 a hot gas passage that bypasses the radiator, the evaporator decompressor, and the evaporator to guide the refrigerant compressed by the compressor to the compressor; and   a flow rate adjusting unit configured to reduce a pressure of the refrigerant flowing through the hot gas passage and adjust a flow rate of the refrigerant flowing in the hot gas passage, wherein   the control unit controls the superheat degree by controlling at least one of the evaporator decompressor or the flow rate adjusting unit based on the state of the refrigerant acquired by the acquisition unit.   
     
     
         5 . The refrigeration cycle device according to  claim 1 , further comprising:
 a gas-liquid separator configured to separate the refrigerant, after being evaporated by the evaporator and before being sucked into the compressor, between gas and liquid, wherein   the gas-liquid separator has an oil return adjusting unit that adjusts a passage area of an oil return unit that returns an oil mixed in the refrigerant from the gas-liquid separator to the compressor, and   the control unit controls the superheat degree by controlling the oil return adjusting unit based on the state of the refrigerant acquired by the acquisition unit.   
     
     
         6 . The refrigeration cycle device according to  claim 1 , further comprising:
 a gas-liquid separator configured to separate the refrigerant, after being evaporated by the evaporator and before being sucked into the compressor, between a gas refrigerant and a liquid refrigerant;   a liquid return unit that guides the liquid refrigerant separated by the gas-liquid separator to the compressor; and   a liquid passage adjusting unit that adjusts a passage area of the liquid return unit, wherein   the control unit controls the superheat degree by controlling the liquid passage adjusting unit based on the state of the refrigerant acquired by the acquisition unit.   
     
     
         7 . The refrigeration cycle device according to  claim 1 , wherein
 the cooled portion includes an electric motor that drives the compression mechanism, and   the acquisition unit calculates a state of the refrigerant after cooling the cooled portion and before flowing into the compression chamber based on an amount of electric power for driving the electric motor, a rotation speed of the electric motor, a pressure of the refrigerant sucked by the compressor, and a pressure and a temperature of the refrigerant discharged by the compressor.   
     
     
         8 . The refrigeration cycle device according to  claim 1 , wherein the acquisition unit detects a temperature and a pressure of the refrigerant after cooling the cooled portion and before flowing into the compression chamber.