Showcase cooling device

Abstract

There is disclosed a showcase cooling device which is capable of cooling all of a plurality of showcases with no difficulty, while suppressing a power consumption of a compressor. A showcase cooling device 1 distributes and supplies a refrigerant discharged from a compressor to evaporators disposed in a plurality of showcases 3 A to 3 H, and comprises chamber inside temperature sensors which detect chamber inside temperatures of the showcases 3 A to 3 H, respectively, and control means for controlling an operation of the compressor, and this control means controls the operation of the compressor on the basis of the chamber inside temperature of the showcase that is hardest to cool among the respective showcases 3 A to 3 H.

1 . A showcase cooling device, which distributes and supplies a refrigerant discharged from a compressor to evaporators disposed in a plurality of showcases, comprising:
 chamber inside temperature sensors which detect chamber inside temperatures of the showcases, respectively; and   control means for controlling an operation of the compressor,   wherein the control means controls the operation of the compressor on the basis of the chamber inside temperature of the showcase that is hardest to cool among the respective showcases.   
     
     
         2 . The showcase cooling device according to  claim 1 ,
 wherein each of the showcases comprises superheat degree regulating means for throttling the refrigerant flowing into the evaporator and regulating, into a predetermined value, the superheat degree of the refrigerant flowing out from the evaporator, and an opening/closing valve which controls the inflow of the refrigerant into the evaporator, and   the control means controls the operation of the compressor on the basis of the chamber inside temperature of the showcase that is hardest to cool, sets a target superheat degree of the other showcases on the basis of the chamber inside temperatures of the other showcases, and opens and closes the opening/closing valve of the other showcases on the basis of the target superheat degree and the predetermined value of the superheat degree.   
     
     
         3 . The showcase cooling device according to  claim 1 ,
 wherein each of the showcases comprises superheat degree regulating means for throttling the refrigerant flowing into the evaporator and regulating, into a predetermined value, the superheat degree of the refrigerant flowing out from the evaporator, and an opening/closing valve which controls the inflow of the refrigerant into the evaporator, and   the control means controls the operation of the compressor on the basis of the chamber inside temperature of the showcase that is hardest to cool, opens and closes the opening/closing valve of the other showcases on the basis of the chamber inside temperatures of the other showcases, and executes the opening and closing of the respective opening/closing valves at different timings, when the opening/closing valves of the other showcases are opened and closed.   
     
     
         4 . The showcase cooling device according to  claim 1 ,
 wherein each of the showcases comprises an expansion valve which throttles the refrigerant flowing into the evaporator and controls, into a target superheat degree, the superheat degree of the refrigerant flowing out from the evaporator, and   the control means defines, as a predetermined value, the target superheat degree of the showcase that is hardest to cool to control a valve open degree of an expansion valve of the showcase, controls the operation of the compressor on the basis of the chamber inside temperature of the showcase, sets the target superheat degree of the other showcases on the basis of the chamber inside temperatures of the other showcases, and controls the valve open degree of the expansion valves of the other showcases.   
     
     
         5 . The showcase cooling device according to  claim 1 ,
 wherein the control means distinguishes the showcase that is hardest to cool among the respective showcases, and   in a case where there is present the other showcase that is harder to cool than the showcase in which the operation of the compressor is controlled on the basis of the chamber inside temperature, the control means switches to a state to control the operation of the compressor on the basis of the chamber inside temperature of the other showcase.   
     
     
         6 . The showcase cooling device according to  claim 5 ,
 wherein the control means distinguishes the showcase that is hardest to cool among the respective showcases, in a state where the chamber inside temperature is stabilized.   
     
     
         7 . The showcase cooling device according to  claim 1 ,
 wherein the control means controls an operation frequency of the compressor on the basis of the chamber inside temperature of the showcase that is hardest to cool.   
     
     
         8 . The showcase cooling device according to  claim 7 ,
 which comprises a blowout temperature sensor disposed in a cold air blowout portion of each of the showcases to detect a blowout temperature of the cold air to each of the showcases,   wherein the control means determines a target blowout temperature of the cold air to the showcase by a PID calculation based on a deviation between the chamber inside temperature of the showcase and a set value of the chamber inside temperature, and   determines a target operation frequency of the compressor and/or the target superheat degree by a PID calculation based on a deviation between the blowout temperature detected by the blowout temperature sensor and the target blowout temperature.   
     
     
         9 . The showcase cooling device according to  claim 7 ,
 which comprises evaporator temperature sensors to detect temperatures of the evaporators of the showcases, respectively,   wherein the control means determines a target evaporator temperature of each of the showcases by a PID calculation based on a deviation between the chamber inside temperature of the showcase and a set value of the chamber inside temperature, and   determines a target operation frequency of the compressor and/or the target superheat degree by a PID calculation based on a deviation between the temperature of each of the evaporators which is detected by the evaporator sensor and the target evaporator temperature.   
     
     
         10 . The showcase cooling device according to  claim 2 ,
 wherein the control means distinguishes the showcase that is hardest to cool among the respective showcases, and   in a case where there is present the other showcase that is harder to cool than the showcase in which the operation of the compressor is controlled on the basis of the chamber inside temperature, the control means switches to a state to control the operation of the compressor on the basis of the chamber inside temperature of the other showcase.   
     
     
         11 . The showcase cooling device according to  claim 10 ,
 wherein the control means distinguishes the showcase that is hardest to cool among the respective showcases, in a state where the chamber inside temperature is stabilized.   
     
     
         12 . The showcase cooling device according to  claim 11 ,
 wherein the control means controls an operation frequency of the compressor on the basis of the chamber inside temperature of the showcase that is hardest to cool.   
     
     
         13 . The showcase cooling device according to  claim 12 ,
 which comprises a blowout temperature sensor disposed in a cold air blowout portion of each of the showcases to detect a blowout temperature of the cold air to each of the showcases,   wherein the control means determines a target blowout temperature of the cold air to the showcase by a PID calculation based on a deviation between the chamber inside temperature of the showcase and a set value of the chamber inside temperature, and   determines a target operation frequency of the compressor and/or the target superheat degree by a PID calculation based on a deviation between the blowout temperature detected by the blowout temperature sensor and the target blowout temperature.   
     
     
         14 . The showcase cooling device according to  claim 3 ,
 wherein the control means distinguishes the showcase that is hardest to cool among the respective showcases, and   in a case where there is present the other showcase that is harder to cool than the showcase in which the operation of the compressor is controlled on the basis of the chamber inside temperature, the control means switches to a state to control the operation of the compressor on the basis of the chamber inside temperature of the other showcase.   
     
     
         15 . The showcase cooling device according to  claim 14 ,
 wherein the control means distinguishes the showcase that is hardest to cool among the respective showcases, in a state where the chamber inside temperature is stabilized.   
     
     
         16 . The showcase cooling device according to  claim 15 ,
 wherein the control means controls an operation frequency of the compressor on the basis of the chamber inside temperature of the showcase that is hardest to cool.   
     
     
         17 . The showcase cooling device according to  claim 16 ,
 which comprises a blowout temperature sensor disposed in a cold air blowout portion of each of the showcases to detect a blowout temperature of the cold air to each of the showcases,   wherein the control means determines a target blowout temperature of the cold air to the showcase by a PID calculation based on a deviation between the chamber inside temperature of the showcase and a set value of the chamber inside temperature, and   determines a target operation frequency of the compressor and/or the target superheat degree by a PID calculation based on a deviation between the blowout temperature detected by the blowout temperature sensor and the target blowout temperature.   
     
     
         18 . The showcase cooling device according to  claim 4 ,
 wherein the control means distinguishes the showcase that is hardest to cool among the respective showcases, and   in a case where there is present the other showcase that is harder to cool than the showcase in which the operation of the compressor is controlled on the basis of the chamber inside temperature, the control means switches to a state to control the operation of the compressor on the basis of the chamber inside temperature of the other showcase.   
     
     
         19 . The showcase cooling device according to  claim 18 ,
 wherein the control means distinguishes the showcase that is hardest to cool among the respective showcases, in a state where the chamber inside temperature is stabilized.   
     
     
         20 . The showcase cooling device according to  claim 19 ,
 wherein the control means controls an operation frequency of the compressor on the basis of the chamber inside temperature of the showcase that is hardest to cool.