Air conditioner for vehicle

An air conditioner for a vehicle, comprising:

• a pump drawing and discharging a heat medium to circulate the heat medium;
• an air-cooling heat exchanger that exchanges sensible heat between the heat medium circulating by the pump and ventilation air to be blown into a vehicle interior to cool and dehumidify the ventilation air;
• a heat-medium and outside-air heat exchanger that exchanges sensible heat between the heat medium and outside air;
• a compressor adapted to draw and discharge a refrigerant in a refrigeration cycle;
• a heat-medium cooling heat exchanger that cools the heat medium by exchanging heat between a low-pressure side refrigerant in the refrigeration cycle and the heat medium;
• a dehumidification mode switching valve that switches between a first dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium cooling heat exchanger, and a second dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium and outside-air heat exchanger;
• a window-fogging-index calculator configured to calculate a window fogging index as an index for a risk degree of window fogging based on a temperature of inside air, a humidity of the inside air, and a temperature of the window glass;
• and
• a switching controller configured to control an operation of the dehumidification mode switching valve based on the window fogging index calculated by the window- fogging-index calculator.

An air conditioner for a vehicle, comprising:

• a pump drawing and discharging a heat medium to circulate the heat medium;
• an air-cooling heat exchanger that exchanges sensible heat between the heat medium circulating by the pump and ventilation air to be blown into a vehicle interior to cool and dehumidify the ventilation air;
• a heat-medium and outside-air heat exchanger that exchanges sensible heat between the heat medium and outside air;
• a compressor adapted to draw and discharge a refrigerant in a refrigeration pm;
• a heat-medium cooling heat exchanger that cools the heat medium by exchanging heat between a low-pressure side refrigerant in the refrigeration cycle and the heat medium;
• a dehumidification mode switching valve that switches between a first dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium cooling heat exchanger, and a second dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium and outside-air heat exchanger;
• and
• a dew-point temperature calculator configured to calculate a dew-point temperature at a window glass based on a temperature of inside air, a humidity of the inside air, and a temperature of the window glass, wherein
• in the second dehumidification mode, a switching controller is configured to control an operation of the dehumidification mode switching valve based on a difference obtained by subtracting the dew-point temperature from the temperature of the window glass.

An air conditioner for a vehicle, comprising:

• a pump drawing and discharging a heat medium to circulate the heat medium;
• an air-cooling heat exchanger that exchanges sensible heat between the heat medium circulating by the pump and ventilation air to be blown into a vehicle interior to cool and dehumidify the ventilation air;
• a heat-medium and outside-air heat exchanger that exchanges sensible heat between the heat medium and outside air;
• a compressor adapted to draw and discharge a refrigerant in a refrigeration cycle;
• a heat-medium cooling heat exchanger that cools the heat medium by exchanging heat between a low-pressure side refrigerant in the refrigeration cycle and the heat medium;
• a dehumidification mode switching valve that switches between a first dehumidification mode for circulation of the heat medium between the air-cooling heat exchanger and the heat-medium cooling heat exchanger, and a second dehumidification mode for circulation of the heat medium between the air-cooling heat exchanger and the heat-medium and outside-air heat exchanger;
• an inside/outside air switching door that switches between an inside-air introduction mode of introducing inside air into the air-cooling heat exchanger and an outside-air introduction mode of introducing outside air into the air-cooling heat exchanger;
• a pump failure detector configured to detect failure of the pump;
• and
• an inside/outside air switching controller configured to control an operation of the inside/outside air switching door to switch to the outside-air introduction mode when the pump failure detector detects failure of the pump.

An air conditioner for a vehicle, comprising:

• a pump drawing and discharging a heat medium to circulate the heat medium;
• an air-cooling heat exchanger that exchanges sensible heat between the heat medium circulating by the pump and ventilation air to be blown into a vehicle interior to cool and dehumidify the ventilation air;
• a heat-medium and outside-air heat exchanger that exchanges sensible heat between the heat medium and outside air;
• a compressor adapted to draw and discharge a refrigerant in a refrigeration cycle;
• a heat-medium cooling heat exchanger that cools the heat medium by exchanging heat between a low-pressure side refrigerant in the refrigeration cycle and the heat medium;
• a dehumidification mode switching valve that switches between a first dehumidification mode for circulation of the heat medium between the air-cooling heat exchanger and the heat-medium cooling heat exchanger, and a second dehumidification mode for circulation of the heat medium between the air-cooling heat exchanger and the heat-medium and outside-air heat exchanger;
• a second pump adapted to draw and discharge the heat medium;
• an air-heating heat exchanger that heats the ventilation air by exchanging sensible heat between the heat medium discharged from the second pump and the ventilation air;
• a compressor failure detector configured to detect failure of the compressor;
• a circulation switching valve that switches between a first circulation state in which the heat medium discharged from the pump circulates between the heat-medium and outside-air heat exchanger and a coolant-to-coolant heat exchanger, and a second circulation state in which the heat medium discharged from the second pump circulates between the air-heating heat exchanger and the coolant-to-coolant heat exchanger;
• and
• a circulation switching controller configured to control an operation of the circulation switching valve to switch to the second circulation state when the compressor failure detector detects failure of the compressor in the first dehumidification mode.

An air conditioner for a vehicle, comprising:

• a pump drawing and discharging a heat medium to circulate the heat medium;
• an air-cooling heat exchanger that exchanges sensible heat between the heat medium circulating by the pump and ventilation air to be blown into a vehicle interior to cool and dehumidify the ventilation air;
• a heat-medium and outside-air heat exchanger that exchanges sensible heat between the heat medium and outside air;
• a compressor adapted to draw and discharge a refrigerant in a refrigeration cycle;
• a heat-medium cooling heat exchanger that cools the heat medium by exchanging heat between a low-pressure side refrigerant in the refrigeration cycle and the heat medium;
• a dehumidification mode switching valve that switches between a first dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium cooling heat exchanger, and a second dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium and outside-air heat exchanger;
• and
• an operation switch configured to output a command for switching from the first dehumidification mode to the second dehumidification mode when being operated by an occupant.

An air conditioner for a vehicle;

• comprising:
• a pump drawing and discharging a heat medium to circulate the heat medium;
• an air-cooling heat exchanger that exchanges sensible heat between the heat medium circulating by the pump and ventilation air to be blown into a vehicle interior to cool and dehumidify the ventilation air;
• a heat-medium and outside-air heat exchanger that exchanges sensible heat between the heat medium and outside air;
• a compressor adapted to draw and discharge a refrigerant in a refrigeration cycle;
• a heat-medium cooling heat exchanger that cools the heat medium by exchanging heat between a low-pressure side refrigerant in the refrigeration cycle and the heat medium;
• a dehumidification mode switching valve that switches between a first dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium cooling heat exchanger;
• and a second dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium and outside-air heat exchanger;
• and
• a switching controller configured to control an operation of the dehumidification mode switching valve to allow the heat medium to flow bypassing the heat-medium cooling heat exchanger when a temperature in connection with a temperature of the refrigerant in the heat-medium cooling heat exchanger is higher than a temperature in connection with the temperature of the heat medium flowing through the air-cooling heat exchanger.

An air conditioner for a vehicle;

• comprising:
• a pump drawing and discharging a heat medium to circulate the heat medium;
• an air-cooling heat exchanger that exchanges sensible heat between the heat medium circulating by the pump and ventilation air to be blown into a vehicle interior to cool and dehumidify the ventilation air;
• a heat-medium and outside-air heat exchanger that exchanges sensible heat between the heat medium and outside air;
• a compressor adapted to draw and discharge a refrigerant in a refrigeration cycle;
• a heat-medium cooling heat exchanger that cools the heat medium by exchanging heat between a low-pressure side refrigerant in the refrigeration cycle and the heat medium;
• a dehumidification mode switching valve that switches between a first dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium cooling heat exchanger, and a second dehumidification mode in which the heat medium circulates between the air-cooling heat exchanger and the heat-medium and outside-air heat exchanger;
• and
• a controller configured to control an operation of the dehumidification mode switching valve such that the first dehumidification mode is switched to the second dehumidification mode, when a refrigerant leak from the refrigeration cycle is determined or detected, or when an amount of the refrigerant within the refrigeration cycle is determined or detected to be less than a predetermined amount.