Refrigeration cycle device
A refrigeration cycle device includes a high-temperature heating medium regulator and a controller. The high-temperature heating medium regulator regulates a high-temperature heating medium flow ratio between the flow rate of high-temperature heating medium flowing in an air heater and the flow rate of high-temperature heating medium flowing in a radiator. The controller controls the high-temperature heating medium regulator to regulate the high-temperature heating medium flow ratio such that excess heat is radiated to air outside the cabin by the radiator, of the heat radiated from the refrigerant to the high-temperature heating medium by a high-pressure-side heat exchanger, with respect to heat required for heating air blown into a cabin by the air heater to have a target outlet temperature.
1. A refrigeration cycle device comprising:
a high-temperature heating medium circuit through which a high-temperature heating medium circulates;
an air heater configured to heat air blown into a cabin by exchanging heat between the high-temperature heating medium and the air;
a radiator configured to radiate heat to air outside the cabin by exchanging heat between the high-temperature heating medium and the air outside the cabin;
a compressor that sucks, compresses, and discharges a refrigerant;
a high-pressure-side heat exchanger configured to radiate heat from the refrigerant to the high-temperature heating medium by exchanging heat between the high-pressure refrigerant discharged from the compressor and the high-temperature heating medium;
a decompression part that decompresses the refrigerant subjected to the heat exchange by the high-pressure-side heat exchanger;
an evaporator that absorbs heat into the refrigerant decompressed by the decompression part to evaporate the refrigerant; and
a flow rate regulator that regulates a radiator-side flow ratio of a flow rate of the high-temperature heating medium flowing in the radiator to a flow rate of the high-temperature heating medium flowing in the high-pressure-side heat exchanger, wherein
a maximum outlet temperature that is a maximum value of a temperature of air heated by the air heater increases as the radiator-side flow ratio decreases, and
a rate of increase in the maximum outlet temperature with respect to a decrease in the radiator-side flow ratio increases as the radiator-side flow ratio decreases.
2. The refrigeration cycle device according to claim 1 , wherein the flow rate regulator is capable of regulating the radiator-side flow ratio so that a fluctuation range of the temperature of the air heated by the air heater becomes equal to or less than an allowable value at the radiator-side flow ratio when the maximum outlet temperature becomes an upper limit outlet temperature that is an upper limit of the temperature of the air heated by the air heater.
3. The refrigeration cycle device according to claim 2 , further comprising a temperature detector that detects the temperature of air heated by the air heater or the high-temperature heating medium flowing into the air heater, wherein
the flow rate regulator is capable of regulating the radiator-side flow ratio so that the fluctuation range of the temperature of the air heated by the air heater becomes equal to or more than an error range of the detected temperature of the temperature detector at the radiator-side flow ratio when the maximum outlet temperature becomes the upper limit outlet temperature.
4. The refrigeration cycle device according to claim 1 , wherein the maximum outlet temperature THmax is expressed by a relationship:
TH max=5.0052 Gw −1.173
with respect to the radiator-side flow ratio Gw.