Refrigeration cycle device

Abstract

A refrigeration cycle device includes a decompression unit configured to decompress a refrigerant, an evaporator configured to evaporate the refrigerant decompressed by the decompression unit, a pressure detector configured to detect an outlet-side pressure of the refrigerant at a refrigerant outlet side of the evaporator, a temperature detector configured to detect an outlet-side temperature of the refrigerant at the refrigerant outlet side of the evaporator, and a controller configured to control an operation of the decompression unit. The controller is configured to calculate a delayed outlet-side temperature by performing a delay process on the outlet-side temperature, and to control the decompression unit by using the outlet-side pressure and the delayed outlet-side temperature.

What is claimed is: 
     
         1 . A refrigeration cycle device comprising:
 a decompression unit configured to decompress a refrigerant;   an evaporator configured to evaporate the refrigerant decompressed by the decompression unit;   a pressure detector configured to detect an outlet-side pressure of the refrigerant at a refrigerant outlet side of the evaporator;   a temperature detector configured to detect an outlet-side temperature of the refrigerant at the refrigerant outlet side of the evaporator; and   a controller configured to control an operation of the decompression unit,   wherein the controller is configured to obtain a delayed outlet-side temperature by performing a delay process on the outlet-side temperature, and to control the decompression unit by using the outlet-side pressure and the delayed outlet-side temperature, and   wherein the controller determines a superheat of the refrigerant at the refrigerant outlet side of the evaporator by using the outlet-side pressure and the outlet-side temperature, and decreases a degree of delay in the delay process in accordance with a decrease in a superheat variation of the superheat per a predetermined reference time when the superheat is equal to or less than a predetermined reference high superheat.   
     
     
         2 . The refrigeration cycle device according to  claim 1 , wherein the controller increases a degree of delay in the delay process in accordance with an increase in the superheat. 
     
     
         3 . The refrigeration cycle device according to  claim 1 , wherein the controller is configured to perform an absolute value control, in which a target throttle opening of the decompression unit is controlled by using the outlet-side pressure and the delayed outlet-side temperature, and an operation of the decompression unit is controlled to bring an opening of the decompression unit closer to the target throttle opening. 
     
     
         4 . The refrigeration cycle device according to  claim 1 , wherein the controller is configured to perform a differential control, in which an operation of the decompression unit is controlled to reduce a difference between the superheat and a predetermined target superheat. 
     
     
         5 . The refrigeration cycle device according to  claim 4 , wherein the controller performs the differential control when the superheat of the refrigerant at the refrigerant outlet side of the evaporator is higher than a predetermined reference high superheat and an absolute value of a superheat variation of the superheat per a predetermined reference time is smaller than a predetermined reference variation. 
     
     
         6 . A refrigeration cycle device comprising:
 a decompression unit configured to decompress a refrigerant;   an evaporator configured to evaporate the refrigerant decompressed by the decompression unit;   a pressure detector configured to detect an outlet-side pressure of the refrigerant at a refrigerant outlet side of the evaporator;   a temperature detector configured to detect an outlet-side temperature of the refrigerant at the refrigerant outlet side of the evaporator; and   a controller configured to control an operation of the decompression unit,   wherein the controller is configured to obtain a delayed outlet-side temperature by performing a delay process on the outlet-side temperature, and to control the decompression unit by using the outlet-side pressure and the delayed outlet-side temperature,   wherein the controller is configured to perform a differential control, in which a superheat of the refrigerant at the refrigerant outlet side of the evaporator is controlled by using the outlet-side pressure and the outlet-side temperature, and an operation of the decompression unit is controlled to reduce a difference between the superheat and a predetermined target superheat, and   wherein the controller performs the differential control when the superheat of the refrigerant at the refrigerant outlet side of the evaporator is higher than a predetermined reference high superheat and an absolute value of a superheat variation of the superheat per a predetermined reference time is smaller than a predetermined reference variation.   
     
     
         7 . The refrigeration cycle device according to  claim 6 , wherein the controller increases a degree of delay in the delay process in accordance with an increase in the superheat. 
     
     
         8 . The refrigeration cycle device according to  claim 6 , wherein the controller decreases a degree of delay in the delay process in accordance with a decrease in a superheat variation of the superheat per a predetermined reference time when the superheat is equal to or less than a predetermined reference high superheat. 
     
     
         9 . The refrigeration cycle device according to  claim 6 , wherein the controller is configured to perform an absolute value control, in which a target throttle opening of the decompression unit is controlled by using the outlet-side pressure and the delayed outlet-side temperature, and an operation of the decompression unit is controlled to bring an opening of the decompression unit closer to the target throttle opening. 
     
     
         10 . A refrigeration cycle device comprising:
 an evaporator that evaporates a refrigerant;   a downstream decompression unit configured to decompress the refrigerant flowing out of the evaporator;   a pressure detector configured to detect an outlet-side pressure of the refrigerant at a refrigerant outlet side of the evaporator;   a temperature detector configured to detect an outlet-side temperature of the refrigerant at the refrigerant outlet side of the evaporator; and   a controller configured to control an operation of the downstream decompression unit,   wherein the controller controls the downstream decompression unit based on the outlet-side pressure and a delayed outlet-side temperature obtained by performing a delay process on the outlet-side temperature, and   wherein the controller determines a superheat of the refrigerant at the refrigerant outlet side of the evaporator by using the outlet-side pressure and the outlet-side temperature, and decreases a degree of delay in the delay process in accordance with a decrease in a superheat variation of the superheat per a predetermined reference time when the superheat is equal to or less than a predetermined reference high superheat.   
     
     
         11 . The refrigeration cycle device according to  claim 10 , further comprising:
 a branch that divides a flow of the refrigerant in a refrigerant cycle into separate streams including first and second streams;   an upstream decompression unit configured to decompresses the refrigerant in the first stream divided at the branch and to allow the refrigerant to flow out to a refrigerant inlet side of the evaporator;   an auxiliary decompression unit configured to decompress the refrigerant in the second stream divided at the branch;   an auxiliary evaporator that evaporates the refrigerant decompressed in the auxiliary decompression unit; and   a junction configured to merge a flow of the refrigerant flowing out of the evaporator and a flow of the refrigerant flowing out of the auxiliary evaporator.   
     
     
         12 . A refrigeration cycle device comprising:
 an evaporator that evaporates a refrigerant;   a downstream decompression unit configured to decompress the refrigerant flowing out of the evaporator;   a pressure detector configured to detect an outlet-side pressure of the refrigerant at a refrigerant outlet side of the evaporator;   a temperature detector configured to detect an outlet-side temperature of the refrigerant at the refrigerant outlet side of the evaporator; and   a controller configured to control an operation of the downstream decompression unit,   wherein the controller controls the downstream decompression unit based on the outlet-side pressure and a delayed outlet-side temperature obtained by performing a delay process on the outlet-side temperature, and   wherein the controller is configured to perform a differential control, in which a superheat of the refrigerant at the refrigerant outlet side of the evaporator is controlled by using the outlet-side pressure and the outlet-side temperature, and an operation of the decompression unit is controlled to reduce a difference between the superheat and a predetermined target superheat, and   wherein the controller performs the differential control when the superheat of the refrigerant at the refrigerant outlet side of the evaporator is higher than a predetermined reference high superheat and an absolute value of a superheat variation of the superheat per a predetermined reference time is smaller than a predetermined reference variation.