Air conditioner for vehicle with heat pump cycle

Abstract

An air conditioner for a vehicle includes a vapor compression refrigeration cycle configured to have a heat pump cycle for heating air to be blown into an interior of a vehicle compartment, and a heating member for heating the air using a coolant of an internal combustion engine of the vehicle as a heat source. In the air conditioner, an operation request signal is output by an air conditioning controller to the internal combustion engine when an outside air temperature is lower than a predetermined threshold.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application is based on Japanese Patent Application No. 2009-152095 filed on Jun. 26, 2009, the contents of which are incorporated herein by reference in its entirety.FIELD OF THE INVENTION[0002]The present invention relates to an air conditioner for a vehicle, which is provided with a heat pump cycle.BACKGROUND OF THE INVENTION[0003]Conventionally, JP-A-10-100652 discloses regarding an air conditioner for a vehicle, which includes a heat-pump heating system for performing a heating operation by use of a heat pump, and a heater system for performing a heating operation by using hot water or heat from a heating element.[0004]JP-A-10-100652 takes into consideration the fact that a heating efficiency of the heat-pump heating system becomes deteriorated under an atmosphere where the temperature of outside air is extremely low. Thus, at the extremely-low outside air temperature, the heating is performed by the heater system, while stopping...

AI Technical Summary

Benefits of technology

[0035]According to another aspect of the present invention, an air conditioner for a vehicle includes: heating means for heating air to be blown into an interior of a vehicle compartment using a coolant of an internal combustion engine as a heat source; an electric heater for heating the air by being supplied with power; and control means for determining a target coolant temperature based on a target air temperature to be blown into the vehicle compartment. In the air conditioner, the control means decreases and corrects the target coolant temperature when the electric heater is operated. Thus, it can prevent heating capacity from being excessive, thereby effectively reducing fuel consumption.

[0036]According to another aspect of the present invention, an air conditioner for a vehicle includes: heating means for heating air to be blown into an interior of a vehicle compartment using a coolant of an internal combustion engine as a heat source; an electric heater for heating the air by being supplied with power; and control means for determining a target coolant temperature based on a target air temperature to be blown into the vehicle compartment, and for decreasing and correcting the target coolant temperature based on power consumption of the electric heater. In the air conditioner, the control means increases a correction amount for decreasing the target coolant temperature, as the power consumption of the electric heater becomes larger. Thus, it can prevent heating capacity from being excessive, thereby effectively reducing fuel consumption.

[0037]According to another aspect of the present invention, an air conditioner for a vehicle includes: heating means for heating air to be blown into an interior of a vehicle compartment by using a coolant of an internal combustion engine as a heat source; a seat heater disposed at a seat for generating heat by being supplied with power; and control means for determining a target coolant temperature based on a target air temperature to be blown into the vehicle compartment. In the air conditioner, the control means decreases and corrects the target coolant temperature when the seat heater is operated. Thus, when the seat heater is operated, the warm feeling given to the passenger can be improved while the fuel consumption can be improved.

[0038]According to another aspect of the present invention, an air conditioner for a vehicle includes: heating means for heating air to be blown into an interior of a vehicle compartment using a coolant of an internal combustion engine as a heat source; a seat heater disposed at a seat for generating heat by being supplied with power; and control means for determining a target coolant temperature based on a target air temperature to be blown into the vehicle compartment, and for decreasing and correcting the target coolant temperature based on power consumption of the seat heater. In the air conditioner, as the power consumption of the seat heater becomes larger, the control means increases a correction amount for decreasing the target coolant temperature. Thus, when the seat heater is operated, it can prevent warm feeling of a passenger from being excessive, while the fuel consumption can be improved.

Problems solved by technology

The technique disclosed in JP-A-10-100652, however, has various problems in practical use.

For example, the heater system using the combustion heater makes it difficult to sufficiently clean exhaust gas from the combustion heater, and thus cannot achieve reduction in emission.

That is, provision of an exhaust emission control system or the like dedicated to the combustion heater is proposed for sufficiently cleaning the exhaust gas from the combustion heater, but is difficult to perform within the limited cost and space for mounting.

For example, the heater system using the PTC heater is difficult to ensure adequate heating capacity within the constraints of cost and mounting space.

In a vehicle for achieving fuel consumption saving by stopping an engine, for example, in a hybrid car, an engine coolant is often at a low temperature, and thus the use of the engine coolant as a heat source for heating cannot ensure adequate heating capacity.

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