Refrigeration device

Abstract

Electric power generated by a generator driven by an engine is converted into an alternating current of any arbitrary frequency by an inverter. A compressor of a refrigeration cycle includes a motor driven by power supplied from the inverter and a refrigerant compression unit rotatably driven by the motor to suck in, compress, and discharge refrigerant. A mode changeover switch is switchable between a start/stop operation mode that allows the engine to start and stop, and a continuous operation mode in which the engine is continuously operated. When the start/stop operation mode is selected by the mode changeover switch, the controller controls the inverter such that the target rotation speed of the compressor is fixed at a high rotation speed which is higher than the rotation speed according to the difference between the set temperature and the internal temperature.

1 . A refrigeration device that cools air in an internal space, comprising:
 an engine for power generation;   a generator driven by the engine to generate electricity;   an inverter that generates an alternating current of a variable frequency from the electric power generated by the generator;   a compressor including
 a motor driven by power supplied from the inverter, and 
 a refrigerant compression unit rotatably driven by the motor to suck in, compress, and discharge refrigerant; 
   a radiator that dissipates heat from the refrigerant discharged from the compressor by exchanging heat between the refrigerant and outside air;   an expansion valve that depressurizes the refrigerant that flows out of the radiator;   an evaporator that cools the air in the internal space by exchanging heat between the refrigerant that flows out of the expansion valve and the air in the internal space, the evaporator causing the evaporated refrigerant to flow out toward the compressor;   a mode changeover switch switchable between a start/stop operation mode that allows the engine to start and stop, and a continuous operation mode in which the engine is continuously operated; and   a controller that controls the inverter such that when the start/stop operation mode is selected by the mode changeover switch, a target rotation speed of the compressor is fixed at a high rotation speed which is higher than a rotation speed according to a difference between a set temperature and an internal temperature.   
     
     
         2 . The refrigeration device of  claim 1 , wherein
 the controller controls the inverter such that, when the start/stop operation mode is selected by the mode changeover switch, the target rotation speed of the compressor is within a maximum rotation speed region.   
     
     
         3 . The refrigeration device of  claim 1 , wherein
 the controller is configured to
 when the start/stop operation mode is selected by the mode changeover switch, control the inverter such that the target rotation speed of the compressor is within a maximum rotation speed region, and 
 when the continuous operation mode is selected by the mode changeover switch, control the inverter such that the target rotation speed of the compressor is a rotation speed corresponding to the difference between the set temperature and the internal temperature of the internal space.