Refrigeration cycle device

Patent metadata

Field	Value
Publication number	US-2018209697-A1
Application number	US-201615744450-A
Country	US
Kind code	A1
Filing date	Sep 23, 2016
Priority date	Oct 27, 2015
Publication date	Jul 26, 2018
Grant date	—

Abstract

A refrigeration cycle device includes a first physical quantity detector that detects a first physical quantity having a correlation with a temperature of refrigerant flowing into an evaporator, a second physical quantity detector that detects a second physical quantity having a correlation with a temperature of ventilation air heat-exchanged in the evaporator to be blown into a space to be cooled, a defrosting operation determination portion that determines whether a defrosting operation of the evaporator is to be started based on whether a temperature difference between the temperature of the refrigerant specified by the first physical quantity and the temperature of the ventilation air specified by the second physical quantity is equal to or larger than a determination threshold value, and a defrosting operation execution portion that performs the defrosting operation of the evaporator when it is determined that defrosting operation of the evaporator is to be started.

First claim

1 . A refrigeration cycle device in which a refrigerant circulates, the refrigeration cycle device comprising:
a compression mechanism that compresses and discharges the refrigerant; a heat radiator that exchanges heat between the refrigerant discharged from the compression mechanism and exterior air to dissipate heat from the refrigerant; an expansion valve that decompresses the refrigerant flowing out of the heat radiator; an evaporator that exchanges heat between the refrigerant decompressed by the expansion valve and ventilation air to be blown into a space to be cooled, to evaporate the refrigerant and to cause the refrigerant to flow to a suction side of the compression mechanism; a first physical quantity detector that detects a first physical quantity having a correlation with a temperature of the refrigerant flowing into the evaporator; a second physical quantity detector that detects a second physical quantity having a correlation with a temperature of the ventilation air that is heat-exchanged in the evaporator to be blown into the space to be cooled; a defrosting operation determination portion that determines whether or not a defrosting operation of the evaporator is to be started based on whether a temperature difference between the temperature of the refrigerant specified based on the first physical quantity, detected by the first physical quantity detector, and the temperature of the ventilation air specified based on the second physical quantity, detected by the second physical quantity detector, is equal to or larger than a determination threshold value; and a defrosting operation execution portion that performs the defrosting operation of the evaporator when the defrosting operation determination portion determines that the defrosting operation of the evaporator is to be started; an outside-air temperature detector that detects an outside air temperature; and a temperature setting portion that sets a target cooling temperature of the space to be cooled, wherein the defrosting operation determination portion specifies the determination threshold value based on the outside air temperature detected by the outside-air temperature detector and the target cooling temperature of the space to be cooled set by the temperature setting portion.

2 . The refrigeration cycle device according to claim 1 , further comprising:
a first expansion valve, wherein the expansion valve is a second expansion valve, the compression mechanism comprising: a first compression mechanism that compresses and discharges the refrigerant; and a second compression mechanism that compresses and discharges the refrigerant discharged from the first compression mechanism, wherein the heat radiator exchanges heat between the refrigerant discharged from the second compression mechanism and the exterior air to dissipate heat from the refrigerant, and the first expansion valve decompresses and expands the refrigerant flowing out of the heat radiator and causes the decompressed refrigerant to flow to the suction side of the second compression mechanism.

3 . The refrigeration cycle device according to claim 1 , wherein
the defrosting operation determination portion determines whether the defrosting operation of the evaporator is to be started based on whether the temperature difference between the temperature of the refrigerant specified based on the first physical quantity detected by the first physical quantity detector and the temperature of the ventilation air specified based on the second physical quantity detected by the second physical quantity detector, continues to be equal to or larger than the determination threshold value over a predetermined time period or longer.

4 . A refrigeration cycle device in which a refrigerant circulates, the refrigeration cycle device comprising:
a compression mechanism that compresses and discharges the refrigerant; a heat radiator that exchanges heat between the refrigerant discharged from the compression mechanism and exterior air to dissipate heat from the refrigerant; an expansion valve that decompresses the refrigerant flowing out of the heat radiator; an evaporator that exchanges heat between the refrigerant decompressed by the expansion valve and ventilation air to be blown into a space to be cooled, to evaporate the refrigerant and to cause the refrigerant to flow to a suction side of the compression mechanism; a first physical quantity detector that detects a first physical quantity having a correlation with a temperature of the refrigerant flowing into the evaporator; a second physical quantity detector that detects a second physical quantity having a correlation with a temperature of the ventilation air that is heat-exchanged in the evaporator to be blown into the space to be cooled; a defrosting operation determination portion that determines whether or not a defrosting operation of the evaporator is to be started based on whether a temperature difference between the temperature of the refrigerant specified based on the first physical quantity, detected by the first physical quantity detector, and the temperature of the ventilation air specified based on the second physical quantity, detected by the second physical quantity detector, is equal to or larger than a determination threshold value; a defrosting operation execution portion that performs the defrosting operation of the evaporator when the defrosting operation determination portion determines that the defrosting operation of the evaporator is to be started; an outside-air temperature detector that detects an outside air temperature; and a temperature setting portion that sets a target cooling temperature of the space to be cooled, wherein the defrosting operation determination portion determines whether the defrosting operation of the evaporator is to be started based on whether the temperature difference between the temperature of the refrigerant specified based on the first physical quantity detected by the first physical quantity detector and the temperature of the ventilation air specified based on the second physical quantity detected by the second physical quantity detector, continues to be equal to or larger than the determination threshold value over a predetermined time period or longer, and the defrosting operation determination portion specifies the predetermined time period based on the outside air temperature detected by the outside-air temperature detector and the target cooling temperature of the space to be cooled set by the temperature setting portion.

5 . The refrigeration cycle device according to claim 1 , wherein
the defrosting operation determination portion makes the determination threshold value to be larger as the temperature difference between the outside air temperature detected by the outside-air temperature detector and the target cooling temperature of the space to be cooled set by the temperature setting portion becomes larger, and determines whether the defrosting operation of the evaporator is to be started by using the determination threshold value.

6 . The refrigeration cycle device according to claim 4 , wherein
the defrosting operation determination portion makes the predetermined time period to be shorter as the target cooling temperature of the space to be cooled becomes lower, and determines whether the defrosting operation of the evaporator is to be started by using the predetermined time period.

7 . The refrigeration cycle device according to any one claim 1 , further comprising:
an abnormality determination portion that determines whether at least one of the first physical quantity detector or the second physical quantity detector is in an abnormal state, wherein the defrosting operation execution portion performs

Assignees

• Denso Corp

Inventors

• Nishida Yasushi

Classifications

• G05B13/042

  in which a parameter or coefficient is automatically adjusted to optimise the performance · CPC title

• F25B49/022

  Compressor control arrangements · CPC title

• F25B1/10 Primary

  with multi-stage compression (with cascade operation F25B7/00) · CPC title

• F25D21/02

  Detecting the presence of frost or condensate · CPC title

• F25B47/006

  for preventing frost · CPC title