Refrigeration apparatus

Abstract

Provided is a refrigeration apparatus which can reduce outlet pressure of a refrigerator even in overload conditions and which can improve refrigeration capacity by liquefying a refrigerant in an intermediate cooler. When outlet pressure of a refrigerator 2 is higher than critical pressure, a control apparatus 60 performs control to reduce the opening degree of a decompression electric valve 31 at the upstream side of an intermediate cooler 30 . Thereby, the refrigerant is liquefied by gas-liquid separation in the intermediate cooler 30 , so that the refrigerator outlet pressure is made less than the critical pressure, and the liquid refrigerant can be sent to a showcase 3 . As a result, the specific enthalpy of the refrigerant at the inlet side of main diaphragm means 41 of the showcase 3 can be reduced, and thereby, the cooling effect can be increased.

What is claimed is: 
     
         1 . A refrigeration apparatus including: a refrigerator having a two-stage compression compressor, an intercooler, a gas cooler, a decompression electric valve, an intermediate cooler, and a gas return electric valve; and a showcase having main diaphragm means and a evaporator,
 the refrigeration apparatus comprising a control apparatus which performs control to reduce the opening degree of the decompression electric valve at the upstream side of the intermediate cooler, when the outlet pressure of the refrigerator is higher than critical pressure.   
     
     
         2 . The refrigeration apparatus according to  claim 1 , wherein, when the difference between the high pressure at the discharge side of the compressor and a design pressure is less than 1 MPa, the control apparatus performs control to reduce the amount of rotation of the compressor. 
     
     
         3 . The refrigeration apparatus according to  claim 2 , wherein, when the difference between the high pressure at the discharge side of the compressor and the design pressure is less than 1 MPa, the control apparatus performs control to reduce the amount of rotation of the compressor, and after securing the difference between the high pressure at the discharge side of the compressor and the design pressure, the control apparatus performs control to reduce the opening degree of the decompression electric valve.