Refrigeration device for container

Abstract

A blown air temperature sensor detects a temperature of blown air which is being blown into a container after having passed sequentially through an evaporator and a heating device. During cooling and dehumidifying operations, a temperature control section controls a cooling section such that a detected blown air temperature detected by the blown air temperature sensor becomes equal to a target temperature. A target control section sets the target temperature to be a first preset temperature which is equal to a preset inside temperature when the cooling operation is performed, and sets the target temperature to be a second preset temperature which is sum of the preset inside temperature and a target increment temperature once a switch has been made from the cooling operation to the dehumidifying operation.

1 . A container refrigeration device comprising:
 a cooling section having   a refrigerant circuit which includes a compressor, a condenser, an expansion mechanism, and an evaporator that are sequentially connected together, and through which a refrigerant circulates, and   a heating device provided downstream of the evaporator with respect to a direction in which sucked air that has been sucked from an inside of a container flows,   the cooling section configured to allow the sucked air to pass sequentially through the evaporator and the heating device, and then, to be blown into the inside of the container,   the container refrigeration device configured to perform a cooling operation in which the heating device is at rest and the sucked air is cooled by the evaporator, and a dehumidifying operation in which the sucked air is cooled and dehumidified by the evaporator and then heated by the heating device, wherein   the container refrigeration device further includes
 a blown air temperature sensor configured to detect a temperature of blown air which is being blown into the inside of the container after having passed sequentially through the evaporator and the heating device, 
 a temperature control section configured to control, during the cooling and dehumidifying operations, the cooling section such that a detected blown air temperature which is a temperature of the blown air detected by the blown air temperature sensor becomes equal to a predetermined target temperature, and 
 a target control section, where the target control section sets, during the cooling operation, the target temperature to be a first preset temperature which is equal to a preset inside temperature that has been determined in advance with respect to an inside temperature of the container, and once a switch has been made from the cooling operation to the dehumidifying operation, the target control section sets the target temperature to be a second preset temperature which is the sum of the preset inside temperature and a predetermined target increment temperature. 
   
     
     
         2 . The container refrigeration device of  claim 1 , further comprising:
 a sucked air temperature sensor configured to detect a temperature of the sucked air, wherein   after a switch has been made from the cooling operation to the dehumidifying operation, the target control section lowers the target temperature if a detected sucked air temperature which is the temperature of the sucked air detected by the sucked air temperature sensor becomes higher than a predetermined reference sucked air temperature, and raises the target temperature if the detected sucked air temperature becomes lower than the reference sucked air temperature.   
     
     
         3 . The container refrigeration device of  claim 2 , wherein
 the reference sucked air temperature is set to be a stabilized sucked air temperature which is the temperature of the sucked air detected by the sucked air temperature sensor when the cooling operation is in a stabilized state, or to be a preset sucked air temperature which is the sum of the preset inside temperature and a predetermined sucked air increment temperature.   
     
     
         4 . The container refrigeration device of  claim 1 , wherein
 the target control section corrects, during the dehumidifying operation, the target temperature in accordance with dehumidifying capacity of the evaporator such that the target temperature rises as the dehumidifying capacity of the evaporator increases.   
     
     
         5 . The container refrigeration device of  claim 2 , wherein
 the target control section corrects the target temperature such that the target temperature becomes equal to or higher than the preset inside temperature.   
     
     
         6 . The container refrigeration device of  claim 1 , wherein
 the heating device is implemented as a reheat heat exchanger into which part of the refrigerant discharged from the compressor flows during the dehumidifying operation.   
     
     
         7 . The container refrigeration device of  claim 6 , further comprising:
 an operation control section configured to perform a first dehumidifying control or a second dehumidifying control when the dehumidifying operation is being performed, wherein
 the first dehumidifying control is performed to allow part of the refrigerant discharged from the compressor to flow into the reheat heat exchanger, and 
 the second dehumidifying control is performed to allow part of the refrigerant discharged from the compressor to flow into the reheat heat exchanger and to control the cooling section such that a discharge pressure of the compressor becomes higher during the second dehumidifying control than during the first dehumidifying control. 
   
     
     
         8 . The container refrigeration device of  claim 1 , wherein
 the heating device is implemented as an electric heater.   
     
     
         9 . The container refrigeration device of  claim 8 , further comprising:
 an operation control section configured to perform a first dehumidifying control or a second dehumidifying control when the dehumidifying operation is being performed, wherein   the first dehumidifying control is performed to drive the electric heater, and   the second dehumidifying control is performed to drive the electric heater with the heating capacity of the electric heater set to be higher than the heating capacity during the first dehumidifying control.   
     
     
         10 . The container refrigeration device of  claim 2 , wherein
 the target control section corrects, during the dehumidifying operation, the target temperature in accordance with dehumidifying capacity of the evaporator such that the target temperature rises as the dehumidifying capacity of the evaporator increases.   
     
     
         11 . The container refrigeration device of  claim 3 , wherein
 the target control section corrects, during the dehumidifying operation, the target temperature in accordance with dehumidifying capacity of the evaporator such that the target temperature rises as the dehumidifying capacity of the evaporator increases.   
     
     
         12 . The container refrigeration device of  claim 3 , wherein
 the target control section corrects the target temperature such that the target temperature becomes equal to or higher than the preset inside temperature.   
     
     
         13 . The container refrigeration device of  claim 4 , wherein
 the target control section corrects the target temperature such that the target temperature becomes equal to or higher than the preset inside temperature.   
     
     
         14 . The container refrigeration device of  claim 2 , wherein
 the heating device is implemented as a reheat heat exchanger into which part of the refrigerant discharged from the compressor flows during the dehumidifying operation.   
     
     
         15 . The container refrigeration device of  claim 3 , wherein
 the heating device is implemented as a reheat heat exchanger into which part of the refrigerant discharged from the compressor flows during the dehumidifying operation.   
     
     
         16 . The container refrigeration device of  claim 4 , wherein
 the heating device is implemented as a reheat heat exchanger into which part of the refrigerant discharged from the compressor flows during the dehumidifying operation.   
     
     
         17 . The container refrigeration device of  claim 5 , wherein
 the heating device is implemented as a reheat heat exchanger into which part of the refrigerant discharged from the compressor flows during the dehumidifying operation.   
     
     
         18 . The container refrigeration device of  claim 2 , wherein the heating device is implemented as an electric heater. 
     
     
         19 . The container refrigeration device of  claim 3 , wherein the heating device is implemented as an electric heater. 
     
     
         20 . The container refrigeration device of  claim 4 , wherein the heating device is implemented as an electric heater.