Air conditioner for vehicle
In an air conditioner for a vehicle with an equipment controlled in accordance with a traveling state of the vehicle, a first heater is disposed to heat air to be blown into a vehicle compartment by using a coolant of the equipment as a heat source, and a second heater is adapted as an auxiliary heater to further heat the air heated by the first heater. A heating capacity of the first heater is controlled such that a temperature of the equipment is approached to a predetermined temperature when the thermal fluid after passing through the first heater returns the equipment, and a heating capacity of the second heater is controlled such that a temperature of air to be blown into the vehicle compartment becomes a desired temperature.
1. An air conditioner for a hybrid vehicle with an engine mounted to the hybrid vehicle, the air conditioner comprising:
a first heater disposed in a thermal fluid circulation circuit in which a thermal fluid heated by exhaust heat of the engine circulates, and configured to heat air to be blown into a vehicle compartment by using the thermal fluid as a heat source;
a second heater disposed downstream of the first heater in a flow direction of the air to be blown into the vehicle compartment, and adapted as an auxiliary heater to further heat the air heated by the first heater;
a first heating capacity control portion controlling a heating capacity of the first heater; and
a second heating capacity control portion controlling a heating capacity of the second heater, wherein
the first heating capacity control portion controls the heating capacity of the first heater such that a temperature of the engine approaches a predetermined temperature regardless of an operation state of the engine when the thermal fluid after passing through the first heater returns to the engine,
the second heating capacity control portion controls the heating capacity of the second heater such that temperature of the air to be blown into the vehicle compartment becomes a desired temperature,
the thermal fluid circulation circuit is provided with a radiator radiating heat of the thermal fluid, and a thermostat valve operated at an operating temperature to cause the thermal fluid to pass through the radiator or to bypass the radiator,
the predetermined temperature is lower than the operating temperature of the thermostat valve,
the first heater is disposed in the thermal fluid circulation circuit to heat air by performing heat exchange between the thermal fluid and air, and
the second heater is a refrigerant condenser of a refrigerant cycle in which refrigerant discharged from a compressor flows into the second heater to heat the air passing through the second heater.
2. The air conditioner according to claim 1 , further comprising
a heating capacity changing portion configured to change the heating capacity of the first heater, wherein
the first heating capacity control portion controls operation of the heating capacity changing portion, so as to control the heating capacity of the first heater.
3. The air conditioner according to claim 2 , wherein
the first heater is a heating heat exchanger configured to perform heat exchange between the thermal fluid flowing therein and air passing therethrough, and
the heating capacity changing portion changes a flow amount of the thermal fluid flowing through the heating heat exchanger, so as to change the heating capacity of the first heater.
4. The air conditioner according to claim 3 , wherein the heating capacity changing portion is a flow adjustment valve that adjusts the flow amount of the thermal fluid flowing through the heating heat exchanger.
5. The air conditioner according to claim 3 , wherein the heating capacity changing portion is configured by a bypass passage through which the thermal fluid flows while bypassing the heating heat exchanger, and an adjustment valve adjusting an open degree of the bypass passage.
6. The air conditioner according to claim 3 , wherein the first heating capacity control portion increases the flow amount of the thermal fluid flowing through the heating heat exchanger in accordance with an increase of the temperature of the thermal fluid before being heat exchanged with the air in the heating heat exchanger.
7. The air conditioner according to claim 2 , wherein
the first heater is a heating heat exchanger configured to perform heat exchange between the thermal fluid flowing therein and air passing therethrough, and
the heating capacity changing portion changes a flow amount of air passing through the heating heat exchanger, so as to change the heating capacity of the first heater.
8. The air conditioner according to claim 7 , wherein the heating capacity changing portion changes a ratio between the flow amount of air passing through the heating heat exchanger and a flow amount of air bypassing the heating heat exchanger, so as to change the flow amount of air passing through the heating heat exchanger.
9. The air conditioner according to claim 1 , wherein the thermal fluid is a coolant for cooling the engine mounted to the vehicle.
10. The air conditioner according to claim 1 , wherein the predetermined temperature is set to be equal to or higher than a necessary temperature required for a heating control of the engine mounted to the vehicle.
11. The air conditioner according to claim 1 , wherein
when a vehicle speed is lower than a predetermined speed, the first heating capacity control portion controls the heating capacity of the first heater to increase the temperature of the engine, as compared with a case where the vehicle speed is not lower than the predetermined speed.
12. The air conditioner according to claim 1 , wherein
the second heater is a refrigerant radiator in which a refrigerant discharged from the compressor of the refrigerant cycle radiates heat to air, and
the second heating capacity control portion controls a discharge capacity of the compressor, so as to control the heating capacity of the refrigerant radiator.
13. The air conditioner according to claim 12 , wherein
the compressor is an electrical compressor that is operated when being supplied with electrical power.
14. The air conditioner according to claim 1 , wherein
the second heating capacity control portion increases the heating capacity of the second heater before the first heating capacity control portion reduces the heating capacity of the first heater.
15. The air conditioner according to claim 1 , wherein
the engine mounted to the vehicle is an internal combustion engine that outputs a drive force for traveling the vehicle.
16. The air conditioner according to claim 1 , wherein
the first heating capacity control portion controls the heating capacity of the first heater such that the temperature of the engine approaches the predetermined temperature within a temperature range equal to or higher than the predetermined temperature.
17. The air conditioner according to claim 1 , wherein
the first heating capacity control portion controls the heating capacity of the first heater such that the temperature of the engine approaches the predetermined temperature within a temperature range equal to or lower than the predetermined temperature.
18. The air conditioner according to claim 1 , further comprising:
an interior heat exchanger that is an evaporator of the refrigerant cycle, and is disposed upstream of the first heater in the flow direction of the air to cool the air; and
a cool air bypass passage through which air after passing through the interior heat exchanger flows while bypassing both the first heater and the second heater.
19. The air conditioner according to claim 1 , wherein the second heater always further heats all the air heated by the first heater when the second heater heats the air heated by the first heater.
20. An air conditioner for a hybrid vehicle with an engine mounted to the hybrid vehicle, the air conditioner comprising:
a first heater disposed in a thermal fluid circulation circuit in which a thermal fluid heated by exhaust heat of the engine circulates, and configured to heat air to be blown into a vehicle compartment by using the thermal fluid as a heat source;
a second heater disposed downstream of the first heater in a flow direction of the air to be blown into the vehicle compartment, and adapted as an auxiliary heater to further heat the air heated by the first heater;
a first heating capacity control portion controlling a heating capacity of the first heater; and
a second heating capacity control portion controlling a heating capacity of the second heater, wherein
the first heating capacity control portion controls the heating capacity of the first heater such that a temperature of the engine becomes equal to or higher than a predetermined temperature regardless of an operation state of the engine when the thermal fluid after passing through the first heater returns to the engine,
the second heating capacity control portion controls the heating capacity of the second heater such that temperature of the air to be blown into the vehicle compartment becomes a desired temperature,
the thermal fluid circulation circuit is provided with a radiator radiating heat of the thermal fluid, and a thermostat valve operated at an operating temperature to cause the thermal fluid to pass through the radiator or to bypass the radiator,
the predetermined temperature is lower than the operating temperature of the thermostat valve,
the first heater is disposed in the thermal fluid circulation circuit to heat air by performing heat exchange between the thermal fluid and air, and
the second heater is a refrigerant condenser of a refrigerant cycle in which refrigerant discharged from a compressor flows into the second heater to heat the air passing through the second heater.
21. The air conditioner according to claim 20 , wherein a temperature of the thermal fluid is used as the temperature of the engine.
22. The air conditioner according to claim 20 , wherein the predetermined temperature is set to be equal to or higher than a necessary temperature required for a heating control of the engine mounted to the vehicle.
23. The air conditioner according to claim 20 , wherein
when a vehicle speed is lower than a predetermined speed, the first heating capacity control portion controls the heating capacity of the first heater to increase the temperature of the engine, as compared with a case where the vehicle speed is not lower than the predetermined speed.
24. The air conditioner according to claim 20 , wherein
the second heating capacity control portion increases the heating capacity of the second heater before the first heating capacity control portion reduces the heating capacity of the first heater.
25. The air conditioner according to claim 20 , wherein the second heater always further heats all the air heated by the first heater when the second heater heats the air heated by the first heater.