Refrigeration apparatus

Abstract

A refrigeration apparatus includes a refrigerant circuit having a main circuit performing a refrigeration cycle and a branch circuit which branches part of high-pressure liquid refrigerant flowing through the main circuit and leads the part of high-pressure liquid refrigerant from a high-pressure part of the main circuit to part of the main circuit having a pressure lower than that of the high-pressure part. The branch circuit is connected to a cooler configured to cool a power element(s) of a power supply device supplying power to drivers of components of the refrigerant circuit by refrigerant. In the refrigeration apparatus, an adjusting mechanism configured to adjust the state of refrigerant flowing through the branch circuit and adjust the temperature of refrigerant passing through the cooler to a target temperature is provided.

1 . A refrigeration apparatus including
 a refrigerant circuit having
 a main circuit in which a compressor, a heat-source-side heat exchanger, an expansion mechanism, and a utilization-side heat exchanger are connected together to perform a refrigeration cycle, 
 a branch circuit which branches part of high-pressure liquid refrigerant flowing through the main circuit and leads the part of high-pressure liquid refrigerant from a high-pressure part of the main circuit to part of the main circuit having a pressure lower than that of the high-pressure part, 
   a power supply device including a power element and supplying power to a driver of a component of the refrigerant circuit, and   a cooler connected to the branch circuit and cooling the power element by refrigerant flowing through the branch circuit, the refrigeration apparatus comprising:   an adjusting mechanism configured to adjust a state of refrigerant flowing through the branch circuit and adjust a temperature of refrigerant passing through the cooler to a target temperature.   
     
     
         2 . The refrigeration apparatus of  claim 1 , wherein
 the adjusting mechanism includes
 a throttle mechanism connected to one end of the cooler of the branch circuit, 
 a throttle valve which is connected to the other end of the cooler of the branch circuit and a degree of opening of which is adjustable, and 
 an opening degree adjuster adjusting the degree of opening of the throttle valve such that an evaporation temperature of refrigerant in the cooler reaches a target temperature. 
   
     
     
         3 . The refrigeration apparatus of  claim 2 , wherein
 the throttle valve is provided downstream of the cooler,   the throttle mechanism is provided upstream of the cooler, and a degree of opening of the throttle mechanism is adjustable, and   the adjusting mechanism further includes a throttle mechanism adjuster adjusting the degree of opening of the throttle mechanism such that a degree of superheating of refrigerant at an outlet of the cooler reaches a target degree of superheating.   
     
     
         4 . The refrigeration apparatus of  claim 3 , wherein
 the opening degree adjuster adjusts, upon a start of the refrigeration apparatus, the degree of opening of the throttle valve to a degree of opening larger than an opening degree adjustable range of a normal operation, and   the throttle mechanism adjuster adjusts, upon the start of the refrigeration apparatus, the degree of opening of the throttle mechanism to a degree of opening larger than the opening degree adjustable range of the normal operation.   
     
     
         5 . The refrigeration apparatus of  claim 3 , further comprising:
 a stop controller configured to, upon stoppage of the refrigeration apparatus, control at least one of the degrees of opening of the throttle valve and the throttle mechanism to a fully-closed state.   
     
     
         6 . The refrigeration apparatus of  claim 3 , further comprising:
 a fixed throttle connected in parallel to the throttle mechanism.   
     
     
         7 . The refrigeration apparatus of  claim 3 , further comprising:
 a fixed throttle connected in series with the first throttle valve.   
     
     
         8 . The refrigeration apparatus of  claim 2 , further comprising:
 a detector configured to detect a physical amount to be an indicator for a possibility of occurrence of dew condensation in the power element or a surrounding component thereof; and   a forcible opening degree reducer configured to, when a detection value of the detector indicates a dew condensation state in which the dew condensation is highly likely to occur in the power element or the surrounding component thereof, forcibly reduce the degree of opening of the throttle valve on behalf of the opening degree adjuster.   
     
     
         9 . The refrigeration apparatus of  claim 8 , wherein
 the detector includes
 a temperature sensor provided in the power element or the surrounding component thereof, and 
 an air temperature sensor detecting a temperature of air around the power supply device, and 
   the forcible opening degree reducer is configured to, when the detection value of the temperature sensor is lower than the detection value of the air temperature sensor and it is determined that the dew condensation state is established, forcibly reduce the degree of opening of the throttle valve on behalf of the opening degree adjuster.   
     
     
         10 . The refrigeration apparatus of  claim 8 , wherein
 the detector includes
 a temperature sensor provided in the power element or the surrounding component thereof, and 
 an air temperature sensor detecting a temperature of air around the power supply device, and 
   the forcible opening degree reducer is configured to, when a temperature obtained by adding a preset temperature increase from an installation part of the temperature sensor to an electrical connection part of the power element to the detection value of the temperature sensor is lower than the detection value of the air temperature sensor and it is determined that the dew condensation state is established, forcibly reduce the degree of opening of the throttle valve on behalf of the opening degree adjuster.   
     
     
         11 . The refrigeration apparatus of  claim 8 , wherein
 the detector includes
 a temperature sensor provided in the power element or the surrounding component thereof, and 
 an air temperature sensor detecting a temperature of air around the power supply device, and 
   the forcible opening degree reducer is configured to, when the detection value of the temperature sensor is lower than a dew-point temperature corresponding to a preset reference relative humidity at an air temperature detected by the air temperature sensor and it is determined that the dew condensation state is established, forcibly reduce the degree of opening of the throttle valve on behalf of the opening degree adjuster.   
     
     
         12 . The refrigeration apparatus of  claim 8 , wherein
 the detector includes a humidity sensor detecting a relative humidity of air around the power element, and   the forcible opening degree reducer is configured to, when the detection value of the humidity sensor is higher than a predetermined upper limit and it is determined that the dew condensation state is established, forcibly reduce the degree of opening of the throttle valve on behalf of the opening degree adjuster.   
     
     
         13 . The refrigeration apparatus of  claim 8 , wherein
 the detector includes
 a humidity sensor detecting a relative humidity of air around the power supply device, 
 an air temperature sensor detecting a temperature of air around the power supply device, and 
 a temperature sensor provided in the power element or the surrounding component thereof, and 
   the forcible opening degree reducer is configured to, when the detection value of the temperature sensor is lower than a dew-point temperature calculated based on the relative humidity detected by the humidity sensor and the air temperature detected by the air temperature sensor, forcibly reduce the degree of opening of the throttle valve on behalf of the opening degree adjuster.   
     
     
         14 . The refrigeration apparatus of  claim 2 , further comprising:
 a dew condensation sensor detecting dew condensation in the power element or the surrounding component thereof; and   a forcible opening degree reducer configured to, when a detection value of the dew condensation sensor indicates a dew condensation state in which dew condensation occurs in the power element or the surrounding component thereof, forcibly reduce the degree of opening of the throttle valve on behalf of the opening degree adjuster.   
     
     
         15 . The refrigeration apparatus of  claim 1 , further comprising:
 a closing unit configured to close the branch circuit upon power shutdown that a power supply to the power supply device is shut down.   
     
     
         16 . The refrigeration apparatus of  claim 15 , wherein
 the closing unit is configured by a solenoid valve provided in the branch circuit and switching to a closed state upon the power shutdown.   
     
     
         17 . The refrigeration apparatus of  claim 3 , further comprising:
 a power shutdown adjusting unit configured to, upon power shutdown that a power supply to the power supply device is shut down, use power generated in a driver of the compressor by rotation of the compressor to adjust at least one of the degrees of opening of the throttle valve and the throttle mechanism to a fully-closed state.   
     
     
         18 . The refrigeration apparatus of  claim 1 , further comprising:
 a pump-down controller configured to
 control the expansion mechanism and at least one of the throttle valve and the throttle mechanism to the fully-closed state to perform a pump-down operation in which refrigerant is stored in the heat-source-side heat exchanger, and 
 estimate an overheating point bringing about an overheating state in which a temperature of the power element is highly likely to exceed a predetermined upper limit to complete the pump-down operation before the overheating point. 
   
     
     
         19 . The refrigeration apparatus of  claim 1 , further comprising:
 a start interrupting unit configured to, when the dew condensation is highly likely to occur in the cooler, interrupt the start of the refrigeration apparatus.   
     
     
         20 . The refrigeration apparatus of  claim 2 , further comprising:
 a detector configured to detect a physical amount to be an indicator for a possibility of occurrence of dew condensation in the power element or a surrounding component thereof; and   a temperature increaser configured to, when a detection value of the detector indicates a dew condensation state in which the dew condensation is highly likely to occur in the power element or the surrounding component thereof, increase a temperature of the power element.   
     
     
         21 . The refrigeration apparatus of  claim 20 , wherein
 the detector includes
 a temperature sensor provided in the power element or the surrounding component thereof, and 
 an air temperature sensor detecting a temperature of air around the power supply device, and 
   the temperature increaser is configured to, when the detection value of the temperature sensor is lower than the detection value of the air temperature sensor and it is determined that the dew condensation state is established, increase the temperature of the power element.   
     
     
         22 . The refrigeration apparatus of  claim 20 , wherein
 the detector includes
 a temperature sensor provided in the power element or the surrounding component thereof, and 
 an air temperature sensor detecting a temperature of air around the power supply device, and 
   the temperature increaser is configured to, when a temperature obtained by adding a preset temperature increase from an installation part of the temperature sensor to an electrical connection part of the power element to the detection value of the temperature sensor is lower than the detection value of the air temperature sensor and it is determined that the dew condensation state is established, increase the temperature of power element.   
     
     
         23 . The refrigeration apparatus of  claim 20 , wherein
 the detector includes
 a temperature sensor provided in the power element or the surrounding component thereof, and 
 an air temperature sensor detecting a temperature of air around the power supply device, and 
   the temperature increaser is configured to, when the detection value of the temperature sensor is lower than a dew-point temperature corresponding to a preset reference relative humidity at an air temperature detected by the air temperature sensor and it is determined that the dew condensation state is established, increase the temperature of the power element.   
     
     
         24 . The refrigeration apparatus of  claim 20 , wherein
 the detector includes a humidity sensor detecting a relative humidity of air around the power element, and   the temperature increaser is configured to, when the detection value of the humidity sensor is higher than a predetermined upper limit and it is determined that the dew condensation state is established, increase the temperature of the power element.   
     
     
         25 . The refrigeration apparatus of  claim 20 , wherein
 the detector includes
 a humidity sensor detecting a relative humidity of air around the power supply device, 
 an air temperature sensor detecting a temperature of air around the power supply device, and 
 a temperature sensor provided in the power element or the surrounding component thereof, and 
   the temperature increaser is configured to, when the detection value of the temperature sensor is lower than a dew-point temperature calculated based on the relative humidity detected by the humidity sensor and the air temperature detected by the air temperature sensor and it is determined that the dew condensation state is established, increase the temperature of the power element.   
     
     
         26 . The refrigeration apparatus of  claim 2 , further comprising:
 a dew condensation sensor detecting dew condensation in the power element or the surrounding component thereof; and   a temperature increaser configured to, when a detection value of the dew condensation sensor indicates a dew condensation state in which dew condensation occurs in the power element or the surrounding component thereof, increase a temperature of the power element.   
     
     
         27 . The refrigeration apparatus of claim  20 , wherein
 the temperature increaser includes a heat generation amount increaser increasing an amount of heat generation of the power element.   
     
     
         28 . The refrigeration apparatus of  claim 20 , wherein
 the temperature increaser includes a heater heating the power element.   
     
     
         29 . The refrigeration apparatus of  claim 27 , further comprising:
 a heat generation amount resetter configured to, when the dew condensation state is cleared, reset the amount of heat generation of the power element increased by the heat generation amount increaser to a normal state before an increase in heat generation amount.   
     
     
         30 . The refrigeration apparatus of  claim 29 , further comprising:
 a forcible heat generation amount resetter configured to, after a predetermined time has lapsed since the amount of heat generation of the power element is increased by the heat generation amount increaser, forcibly reset the amount of heat generation of the power element increased by the heat generation amount increaser to the normal state before the increase in heat generation amount.   
     
     
         31 . The refrigeration apparatus of  claim 27 , wherein
 the heat generation amount increaser increases a current value of the compressor to increase the amount of heat generation of the power element controlling the compressor.   
     
     
         32 . The refrigeration apparatus of  claim 27 , wherein
 the power element is a switching element, and   the heat generation amount increaser increases a switching frequency of the switching element to increase the amount of heat generation of the power element.   
     
     
         33 . The refrigeration apparatus of  claim 27 , wherein
 the power element is a switching element, and   the heat generation amount increaser increases a loss of the switching element to increase the amount of heat generation of the power element.   
     
     
         34 . The refrigeration apparatus of  claim 27 , wherein
 the heat generation amount increaser increases a conduction loss of the power element to increase the amount of heat generation of the power element.