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.

1 . An air conditioner for a vehicle, comprising:
 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;   heating means for heating the air using a coolant of an internal combustion engine of the vehicle as a heat source; and   control means for outputting an operation request signal to the internal combustion engine when an outside air temperature is lower than a predetermined threshold.   
     
     
         2 . The air conditioner for a vehicle according to  claim 1 , further comprising an electric heater for heating the air by being supplied with power,
 wherein, when the outside air temperature is lower than the predetermined threshold, the control means outputs another operation request signal to the electric heater, in addition to the internal combustion engine.   
     
     
         3 . The air conditioner for a vehicle according to  claim 1 , further comprising
 determining means for determining whether a possibility of fogging of a windowpane of the vehicle is high or low, wherein   when the possibility of fogging of the windowpane is high, the control means sets a required number of revolutions of the internal combustion engine to be higher than that when the possibility of fogging of the windowpane is low.   
     
     
         4 . The air conditioner for a vehicle according to  claim 1 , further comprising
 a vehicle-interior temperature setting switch for setting a temperature of an interior of the vehicle compartment by a passenger's operation,   wherein, when a preset temperature set by the vehicle-interior temperature setting switch is higher than a predetermined set temperature, the control means sets a required number of revolutions of the internal combustion engine to be higher than that when the preset temperature is lower than the predetermined set temperature.   
     
     
         5 . The air conditioner for a vehicle according to  claim 1 , wherein the vapor compression refrigeration cycle is configured to be switched to the heat pump cycle, and to a cooler cycle for cooling the air to be blown into the interior of the vehicle compartment, and
 wherein, when the outside air temperature is lower than the predetermined threshold, the control means outputs the operation request signal to the internal combustion engine, and outputs a control signal for switching to the cooler cycle, to the vapor compression refrigeration cycle.   
     
     
         6 . The air conditioner for a vehicle according to  claim 1 , wherein, when the outside air temperature is lower than the predetermined threshold, the control means outputs the operation request signal to the internal combustion engine, and outputs another operation request signal of the heat pump cycle, to the vapor compression refrigeration cycle. 
     
     
         7 . An air conditioner for a vehicle, comprising:
 a vapor compression refrigeration cycle including an outdoor heat exchanger for exchanging heat between refrigerant and outside air, and being configured to have a heat pump cycle for heating air to be blown into an interior of a vehicle compartment;   heating means for heating the air using a coolant of an internal combustion engine as a heat source;   a vehicle-interior temperature setting switch for setting a temperature of the interior of the vehicle compartment by a passenger's operation; and   control means for outputting an operation request signal to the internal combustion engine when a preset temperature set by the vehicle-interior temperature setting switch is higher than a predetermined set temperature.   
     
     
         8 . An air conditioner for a vehicle, comprising:
 a vapor compression refrigeration cycle including an outdoor heat exchanger for exchanging heat between refrigerant and outside air, and being configured to have a heat pump cycle for heating air to be blown into an interior of a vehicle compartment;   heating means for heating the air using a coolant of an internal combustion engine as a heat source; and   control means for determining whether or not an operation request signal is output to each of the vapor compression refrigeration cycle and the internal combustion engine, wherein   when an outside air temperature is lower than a first predetermined temperature, the control means outputs the operation request signal to the internal combustion engine without outputting an operation request signal of the heat pump cycle to the vapor compression refrigeration cycle,   when the outside air temperature is higher than the first predetermined temperature and lower than a second predetermined temperature that is higher than the first predetermined temperature, the control means outputs the operation request signal of the heat pump cycle to the vapor compression refrigeration cycle, and also outputs the operation request signal to the internal combustion engine, and   when the outside air temperature is higher than the second predetermined temperature, the control means outputs the operation request signal of the heat pump cycle to the vapor compression refrigeration cycle without outputting the operation request signal to the internal combustion engine.   
     
     
         9 . The air conditioner for a vehicle according to  claim 8 , wherein, in a case where both of a heating by the heat pump cycle and a heating by the heating means are performed, the control means stops the heat pump cycle when a temperature of the coolant increases to more than a predetermined temperature. 
     
     
         10 . The air conditioner for a vehicle according to  claim 8 , wherein
 the vapor compression refrigeration cycle is configured to be switched to the heat pump cycle, and to a cooler cycle for cooling and dehumidifying the air to be blown into the interior of the vehicle compartment, and   when a temperature of the coolant of the internal combustion engine increases to more than a predetermined temperature, the control means outputs an operation request signal of the cooler cycle to the vapor compression refrigeration cycle.   
     
     
         11 . The air conditioner for a vehicle according to  claim 1 , wherein,
 when the temperature of the coolant is lower than a predetermined reference value in heating by the heating means, the control means sets a required number of revolutions of the internal combustion engine higher than that when the coolant temperature is higher than the predetermined reference.   
     
     
         12 . An air conditioner for a vehicle, comprising:
 a vapor compression refrigeration cycle including a compressor for compressing and discharging a refrigerant, the vapor compression refrigeration cycle being configured to be switched to a cooler cycle for cooling air to be blown into an interior of a vehicle compartment, and to a heat pump cycle for heating the air to be blown into the interior of the vehicle compartment; and   control means adapted to stop the compressor when a pressure of the refrigerant is lower than a predetermined pressure,   wherein the control means set the predetermined pressure smaller in the heat pump cycle, as compared to in the cooler cycle.   
     
     
         13 . The air conditioner for a vehicle according to  claim 2 , wherein the control means determines a target coolant temperature based on a target air temperature to be blown into the vehicle compartment, and decreases and corrects the target coolant temperature when the electric heater is operated. 
     
     
         14 . The air conditioner for a vehicle according to  claim 2 , wherein
 the control means determines a target coolant temperature based on a target air temperature to be blown into the vehicle compartment, and decreases and corrects the target coolant temperature based on power consumption of the electric heater, and   the control means causes a correction amount for decreasing the target coolant temperature to be increased as the power consumption of the electric heater becomes larger.   
     
     
         15 . The air conditioner for a vehicle according to  claim 1 , further comprising a seat heater disposed at a seat for generating heat by being supplied with power,
 wherein, when the outside air temperature is lower than the predetermined threshold, the control means outputs an operation request signal to the seat heater in addition to the internal combustion engine.   
     
     
         16 . The air conditioner for a vehicle according to  claim 15 , wherein the control means determines a target coolant temperature based on a target air temperature to be blown into the vehicle compartment, and decreases and corrects the target coolant temperature when the seat heater is operated. 
     
     
         17 . The air conditioner for a vehicle according to  claim 15 , wherein
 the control means determines a target coolant temperature based on a target air temperature to be blown into the vehicle compartment, and decreases and corrects the target coolant temperature based on power consumption of the seat heater, and   the control means causes a correction amount for decreasing the target coolant temperature to be increased as the power consumption of the seat heater becomes large.   
     
     
         18 . An air conditioner for a vehicle, comprising:
 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,   wherein the control means decreases and corrects the target coolant temperature when the electric heater is operated.   
     
     
         19 . An air conditioner for a vehicle, comprising:
 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,   wherein the control means increases a correction amount for decreasing the target coolant temperature, as the power consumption of the electric heater becomes larger.   
     
     
         20 . An air conditioner for a vehicle, comprising:
 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,   wherein the control means decreases and corrects the target coolant temperature when the seat heater is operated.   
     
     
         21 . An air conditioner for a vehicle, comprising:
 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,   wherein, as the power consumption of the seat heater becomes larger, the control means increases a correction amount for decreasing the target coolant temperature.