AIR CONDITIONER FOR VEHICLE

• US 20160339767A1
• Filed: 01/26/2015
• Published: 11/24/2016
• Est. Priority Date: 01/29/2014
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: ENOMOTO, Norihiko, KAKEHASHI, Nobuharu, OMI, Yasumitsu, MAKIHARA, Masamichi, KISHITA, Hiroshi
• Granted Patent: US 10,479,170 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60H 1/00278 for the battery arrangement of batteries B60R16/04
• CPC Class Codes: B60H 1/004 for vehicles having a combustion engine and electric drive means, e.g. hybrid electric vehicles
• CPC Class Codes: B60H 1/00428 electric
• CPC Class Codes: B60H 1/00785 by the detection of humidity or frost
• CPC Class Codes: B60H 1/00864 Ventilators and damper doors
• CPC Class Codes: B60H 1/00899 Controlling the flow of liquid in a heat pump system controlling the properties of the refrigerant liquid, e.g. pressure or temperature, B60H1/3204
• CPC Class Codes: B60H 1/3207 for minimizing the humidity of the air
• CPC Class Codes: B60H 1/32281 comprising a single secondary circuit, e.g. at evaporator or condenser side
• CPC Class Codes: B60H 1/32284 comprising two or more secondary circuits, e.g. at evaporator and condenser side
• CPC Class Codes: B60H 2001/00307 Component temperature regulation using a liquid flow
• CPC Class Codes: B60H 2001/00928 comprising a secondary circuit
• CPC Class Codes: B60H 2001/3245 of air
• CPC Class Codes: B60H 2001/3255 related to temperature
• CPC Class Codes: B60H 2001/3266 related to the operation of the vehicle
• CPC Class Codes: B60H 2001/3291 Locations with heat exchange within the refrigerant circuit itself
• CPC Class Codes: F25B 2339/047 Water-cooled condensers
• CPC Class Codes: F25B 25/005 using primary and secondary systems
• CPC Class Codes: F25B 2700/1931 Discharge pressures
• CPC Class Codes: F25B 2700/1933 Suction pressures
• CPC Class Codes: F25B 2700/21151 at the suction side of the compressor
• CPC Class Codes: F25B 2700/21152 : at the discharge side of the compressor
• CPC Class Codes: F25B 29/003 : of the compression type system

Abstract

An air conditioner for a vehicle includes a pump that draws and discharges a heat medium, a cooler core that exchanges sensible heat between the heat medium and ventilation air 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, and first and second switching valves that switch between a first dehumidification mode for circulation of the heat medium between the cooler core and the heat-medium cooling heat exchanger and a second dehumidification mode for circulation of the heat medium between the cooler core and the heat-medium and outside-air heat exchanger.

Claims

1. 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; and

a dehumidification mode switching portion 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.

2. The air conditioner for a vehicle according to claim 1, further comprising:

a detector adapted to detect at least one of a temperature of an inside air, a humidity of the inside air, a temperature of the outside air, a temperature of the heat medium, and a temperature of a window glass; and

a switching control unit adapted to control an operation of the dehumidification mode switching portion based on a detection result by the detector.

3. The air conditioner for a vehicle according to claim 2, wherein

the switching control unit controls the operation of the dehumidification mode switching portion to switch to the second dehumidification mode when a temperature in connection with the temperature of the outside air is less than a temperature in connection with a dew-point temperature of the ventilation air flowing into the air-cooling heat exchanger.

5. The air conditioner for a vehicle according to claim 1, further comprising

a flow-rate adjustment portion that adjusts at least one of a flow rate of the heat medium flowing through the heat-medium and outside-air heat exchanger, a flow rate of the outside air flowing through the heat-medium and outside-air heat exchanger, and a flow rate of the heat medium flowing through the air-cooling heat exchanger.

6. The air conditioner for a vehicle according to claim 2, further comprising:

a flow-rate adjustment portion that adjusts at least one of a flow rate of the heat medium flowing through the heat-medium and outside-air heat exchanger, a flow rate of the outside air flowing through the heat-medium and outside-air heat exchanger, and a flow rate of the heat medium flowing through the air-cooling heat exchanger; and

a flow-rate control unit that controls an operation of the flow-rate adjustment portion such that a temperature in connection with a temperature of the ventilation air blown from the air-cooling heat exchanger approaches a target temperature in the second dehumidification mode.

7. The air conditioner for a vehicle according to claim 6, wherein

in the second dehumidification mode, the flow-rate control unit controls an operation of the flow-rate adjustment portion such that the at least one flow rate is increased as the temperature of the outside air increases.

8. The air conditioner for a vehicle according to claim 7, wherein

the switching control unit controls an operation of the dehumidification mode switching portion to switch to the first dehumidification mode after the flow-rate control unit increases the at least one flow rate by a predetermined flow rate or more in the second dehumidification mode.

9. The air conditioner for a vehicle according to claim 7, wherein

the switching control unit controls the operation of the dehumidification mode switching portion to switch to the first dehumidification mode when the temperature in connection with the temperature of the ventilation air brown from the air-cooling heat exchanger exceeds the target temperature even after the flow-rate control unit increases the at least one flow rate by a predetermined flow rate or more in the second dehumidification mode.

10. The air conditioner for a vehicle according to claim 6, further comprising:

a window-fogging-index calculating portion that calculates a window fogging index as an index for a risk degree of window fogging based on a temperature of an inside air, a humidity of the inside air, and a temperature of the window glass, wherein

in the second dehumidification mode, the flow-rate control unit controls the operation of the flow-rate adjustment portion based on the window fogging index calculated by the window-fogging-index calculating portion.

11. The air conditioner for a vehicle according to claim 6, further comprising:

a dew-point temperature calculating portion that calculates a dew-point temperature at the window glass based on a temperature of an inside air, a humidity of the inside air, and a temperature of the window glass, wherein

in the second dehumidification mode, the flow-rate control unit controls the operation of the flow-rate adjustment portion such that the at least one flow rate is increased as a difference obtained by subtracting the dew-point temperature from a temperature of the window glass decreases.

12. The air conditioner for a vehicle according to claim 1, further comprising:

a window-fogging-index calculating portion that calculates a window fogging index as an index for a risk degree of window fogging based on a temperature of an inside air, a humidity of the inside air, and a temperature of the window glass, wherein

the switching control unit controls the operation of the dehumidification mode switching portion based on the window fogging index calculated by the window-fogging-index calculating portion.

13. The air conditioner for a vehicle according to claim 1, further comprising:

a dew-point temperature calculating portion that calculates a dew-point temperature at the window glass based on a temperature of an inside air, a humidity of the inside air, and a temperature of the window glass, wherein

in the second dehumidification mode, the switching control unit controls the operation of the dehumidification mode switching portion based on a difference obtained by subtracting the dew-point temperature from the temperature of the window glass.

14. The air conditioner for a vehicle according to claim 1, further comprising:

an inside/outside air switching portion that switches between an inside-air introduction mode of introducing the inside air into the air-cooling heat exchanger and an outside-air introduction mode of introducing the outside air into the air-cooling heat exchanger;

a pump failure detecting portion adapted to detect failure of the pump; and

an inside/outside air switching control unit that controls an operation of the inside/outside air switching portion to switch to the outside-air introduction mode when the pump failure detecting portion detects failure of the pump.

15. The air conditioner for a vehicle according to claim 1, further comprising:

a heat transfer portion that transfers heat between a heat-generating device generating heat during operation and the heat medium;

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 detecting portion adapted to detect failure of the compressor; and

a circulation switching portion 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 the heat transfer portion, and a second circulation state in which the heat medium discharged from the second pump circulates between the air-heating heat exchanger and the heat transfer portion; and

a circulation switching control unit that controls an operation of the circulation switching portion to switch to the second circulation state when the compressor failure detecting portion detects failure of the compressor in the first dehumidification mode.

16. The air conditioner for a vehicle according to claim 1, further comprising:

an inside/outside air rate adjustment portion adapted to adjust respective rates of inside air and outside air in the ventilation air, wherein

the inside/outside air rate adjustment portion and the dehumidification mode switching portion are capable of switching to a dehumidification-stopping mode in which the rate of the outside air in the ventilation air is equal to or more than a predetermined rate, and the heat medium does not circulate through the air-cooling heat exchanger.

17. The air conditioner for a vehicle according to claim 16, further comprising:

a switching control unit that controls an operation of the dehumidification mode switching portion to switch to the dehumidification-stopping mode when a temperature of the outside air is less than a predetermined temperature.

18. The air conditioner for a vehicle according to claim 1, further comprising:

a switching control unit that controls an operation of the dehumidification mode switching portion to switch to the second dehumidification mode when a temperature of the outside air is less than a predetermined temperature.

19. The air conditioner for a vehicle according to claim 1, further comprising:

a switching control unit that controls an operation of the dehumidification mode switching portion to cool and dehumidify the ventilation air in the second dehumidification mode when a pressure of the refrigeration cycle is estimated, determined, or detected to be less than a predetermined value in intending to cool and dehumidify the ventilation air.

20. The air conditioner for a vehicle according to claim 1, further comprising:

an inside/outside air rate adjustment portion adapted to adjust respective rates of inside air and outside air in the ventilation air; and

a switching control unit that controls an operation of the dehumidification mode switching portion to switch to the second dehumidification mode when the rate of the inside air in the ventilation air is equal to or more than a predetermined rate.

21. The air conditioner for a vehicle according to claim 1, further comprising:

an inside/outside air rate adjustment portion adapted to adjust respective rates of inside air and outside air in the ventilation air;

an operation portion that outputs a command for setting the rate of the inside air in the ventilation air to a predetermined rate or more when being operated by an occupant; and

a switching control unit that controls an operation of the dehumidification mode switching portion to switch to the second dehumidification mode when the operation portion is operated by the occupant, and a temperature of the outside air is less than a predetermined temperature.

22. The air conditioner for a vehicle according to claim 1, further comprising:

an operation portion that outputs a command for switching from the first dehumidification mode to the second dehumidification mode when being operated by an occupant.

23. The air conditioner for a vehicle according to claim 16, further comprising:

a switching control unit that controls an operation of the dehumidification mode switching unit to switch to the second dehumidification mode when a temperature of the ventilation air drawn into the air-cooling heat exchanger is higher than a temperature in connection with a temperature of the outside air by a predetermined temperature or more in the dehumidification-stopping mode.

24. The air conditioner for a vehicle according to claim 1, further comprising:

a switching control unit that controls an operation of the dehumidification mode switching portion 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.

25. The air conditioner for a vehicle according to claim 1, further comprising:

an inside/outside air rate adjustment portion adapted to adjust respective rates of inside air and outside air in the ventilation air; and

a control unit that controls an operation of the inside/outside air rate adjustment portion to increase the rate of the outside air in the ventilation air when a vehicle speed is higher than a predetermined speed in the second dehumidification mode.

26. The air conditioner for a vehicle according to claim 1, further comprising:

an inside/outside air rate adjustment portion adapted to adjust respective rates of inside air and outside air in the ventilation air; and

a control unit that controls an operation of the inside/outside air rate adjustment portion such that as a flow rate of the heat medium in the air-cooling heat exchanger decreases, or as a flow rate of the heat medium in the heat-medium and outside-air heat exchanger decreases, the rate of the outside air in the ventilation air is increased in the second dehumidification mode.

27. The air conditioner for a vehicle according to claim 1, further comprising:

an inside/outside air rate adjustment portion adapted to adjust respective rates of inside air and outside air in the ventilation air; and

a control unit that controls an operation of the inside/outside air rate adjustment portion to increase the rate of the outside air in the ventilation air depending on a decrease in temperature of the outside air in the second dehumidification mode.

28. An air conditioner for a vehicle according to claim 1, further comprising:

a device to be cooled that is cooled by discharging heat to the heat medium; and

a switching control unit that controls an operation of the dehumidification mode switching portion to switch to the first dehumidification mode when an amount of heat discharged to the heat medium from the device to be cooled exceeds a predetermined heat amount, when a temperature of the heat medium exceeds a predetermined temperature, or when a rate of increase of the temperature of the heat medium exceeds a predetermined value in the second dehumidification mode.

29. The air conditioner for a vehicle according to claim 1, wherein

the dehumidification mode switching portion is configured to enable switching to a third dehumidification mode in which the heat medium circulates among the air-cooling heat exchanger, the heat-medium cooling heat exchanger, and the heat-medium and outside-air heat exchanger.

30. The air conditioner for a vehicle according to claim 29, further comprising:

a switching control unit that controls an operation of the dehumidification mode switching portion in such a manner as to switch to the first dehumidification mode, the third dehumidification mode, and the second dehumidification mode in this order as a temperature of the outside air decreases.

31. The air conditioner for a vehicle according to claim 29, further comprising:

a flow-rate control unit that controls a flow rate of the refrigerant flowing through the heat-medium cooling heat exchanger or a flow rate of the heat medium or ventilation air flowing through the air-cooling heat exchanger such that a temperature of the heat medium having a heat exchanged at the air-cooling heat exchanger is higher than a temperature of the outside air by a predetermined temperature or more in the third dehumidification mode.

32. The air conditioner for a vehicle according to claim 1, further comprising:

a casing that forms an outside air passage for outside air to flow toward an inner surface of a vehicle window glass and an inside air passage for inside air to flow toward a foot area of an occupant, wherein

the air-cooling heat exchanger is disposed in the casing such that both the outside air in the outside air passage and the inside air in the inside air passage pass through the air-cooling heat exchanger.

33. The air conditioner for a vehicle according to claim 32, wherein

a part of the air-cooling heat exchanger positioned on an upstream side of a heat medium flow is disposed in the outside air passage.

34. The air conditioner for a vehicle according to claim 1, further comprising:

a controller that controls an operation of the dehumidification mode switching portion such that the second dehumidification mode is switched from the first 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.

4. An air conditioner for a vehicle, comprising:

a pump adapted to draw and discharge a heat medium;

a heat-medium and outside-air heat exchanger that exchanges sensible heat between the heat medium and outside air;

an air-cooling heat exchanger that exchanges sensible heat between the heat medium and ventilation air to be blown into a vehicle interior; and

a controller that allows the heat medium to circulate between the air-cooing heat exchanger and the heat-medium and outside-air heat exchanger when a temperature in connection with a temperature of the outside air is estimated or determined to be less than a temperature in connection with a dew-point temperature of the ventilation air flowing into the air-cooling heat exchanger.