JP2012001036A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for a vehicle that performs control capable of preventing a window, in particular, a windshield from fogging up, without wasted electricity consumption, when dehumidifying upon heating.SOLUTION: The air conditioner includes: a temperature sensor 5 which is an internal air temperature detector for detecting an air temperature of the inside of the vehicle; and a temperature sensor 6 which is an air temperature detector for detecting the air temperature of the outside of the vehicle. A dew point temperature of the inside of the vehicle is calculated with temperatures detected by the respective temperature sensors and setting humidity or humidity detected by a humidity sensor. The air conditioner compares the dew point temperature with the air temperature to determine whether the window, in particular, the windshield has fogged up. As a result, only when the window, in particular, the windshield is likely to fog up due to high humidity of outside air upon heating, the outside air is dehumidified by a first in-vehicle heat exchanger 10, and is afterward heated by a second in-vehicle heat exchanger 11.

Description

  The present invention relates to a vehicle air conditioner that can heat a vehicle interior used in an electric vehicle, a hybrid vehicle, or the like that is difficult to obtain a heat source for heating.

  2. Description of the Related Art Conventionally, in air conditioners of electric vehicles and hybrid vehicles, a system using a cooler that drives a compressor with a motor and an electric heater is used in part.

  Recently, a system using a heat pump cycle has become mainstream from the viewpoint of power saving during heating, and there is a system that performs cooling, heating, dehumidification, etc. using a refrigeration cycle that drives and controls an electric compressor (for example, non-patent) Reference 1).

  FIG. 3 shows an example of a heat pump system using a four-way valve. The refrigerant during cooling is discharged from the compressor 101, flows through the outdoor heat exchanger 103 through the four-way valve 102, dissipates heat, depressurizes with the cooling throttle 104, absorbs heat with the evaporator (evaporator) 105, and returns to the compressor 101.

  At the time of heating, the four-way valve 102 is switched, the refrigerant flows through the condenser 106 to dissipate heat, and the outdoor heat exchanger 103 is operated as an evaporator. In the case of dehumidification, a so-called reheat method is employed in which a refrigerant is passed in the order of the condenser 106, the heating throttle 107, the outdoor heat exchanger 103, the cooling throttle 104, the evaporator 105, etc., and the air is cooled and dehumidified to perform overheating.

Electric Vehicle Handbook Editorial Committee “Electric Vehicle Handbook” published by Maruzen Co., Ltd. (Fig. 5.151)

  In such conventional vehicle air conditioners, a heat pump system configuration that can be dehumidified during heating has been developed by the reheat method, but by utilizing the characteristics of the heat pump system, wasteful power is consumed particularly in dehumidification during heating. There has been a problem that control is not performed to prevent fogging of windows, particularly windshields, without consuming.

  Therefore, the present invention solves the above-described conventional problems, and provides a vehicle air conditioner that can perform control so as to suppress the fogging of windows, particularly windshields, without consuming unnecessary power in dehumidification during heating. The purpose is to do.

  In order to achieve this object, the present invention provides a supply air passage from an outside air introduction port for introducing outside air to an air conditioning outlet for blowing conditioned air into the vehicle, and an inside air from the inside air introduction port for introducing inside air. An inside air discharge path to the inside air discharge port for discharging to the outside air, an outside air blowing means for generating an air flow from the outside air introduction port to the air conditioning outlet in the supply air blowing passage, and an inside air discharge passage from the inside air introduction port to the inside air discharge passage An inside air blowing means for generating an air flow toward the inside air discharge port, a first in-vehicle heat exchanger and a second in-vehicle heat exchanger for cooling or heating air flowing through the supply air passage, a condenser during cooling operation, An outside heat exchanger that exchanges heat with outside air as an evaporator during heating operation, the first in-vehicle heat exchanger, the second in-vehicle heat exchanger, and a heat pump that circulates refrigerant between the outside heat exchanger and the compressor; The above A heat recovery unit that recovers heat by exchanging heat between the inside air flowing through the discharge path and the outside air introduced from the outside air inlet, an inside air temperature detecting means that detects the air temperature inside the vehicle, and an outside that detects the air temperature outside the vehicle An air temperature detecting means is provided, and dehumidification during heating operation is controlled using the temperature detected by the inside air temperature detecting means and the temperature detected by the outside air temperature detecting means, thereby achieving the intended purpose. Is.

  According to the present invention, the refrigerant is caused to flow in series between the vehicle exterior heat exchanger and the first vehicle interior heat exchanger, the interior air temperature detection means for detecting the air temperature inside the vehicle, and the ambient temperature detection for detecting the air temperature outside the vehicle. Means for controlling the dehumidification during heating operation using the temperature detected by the inside air temperature detecting means and the temperature detected by the outside air temperature detecting means, so that the outside air is highly humid during heating and windows, particularly the windshield Only when there is a risk of fogging, after dehumidifying with the first in-vehicle heat exchanger, it can be heated with the second in-vehicle heat exchanger, so the effect of suppressing the fogging of windows, especially windshields, without consuming wasteful power. Obtainable.

  Furthermore, heat recovery is performed from the air-conditioned interior air by providing a heat recovery device that recovers heat by exchanging heat between the inside air flowing through the inside air discharge path and the outside air introduced from the outside air introduction port, Since the outside air to be introduced can be brought close to the vehicle interior environment, the effect of reducing the air conditioning load in the vehicle and providing a vehicle air conditioner having an energy saving effect can be obtained.

  Further, by providing a plurality of outside air inlets, heat is not collected from the air-conditioned vehicle interior, and the outside air can be sent directly to the first vehicle heat exchanger, thereby further suppressing fogging of windows, particularly the windshield. The effect that can be obtained.

1 is a schematic configuration diagram of a vehicle air conditioner according to Embodiment 1 of the present invention. The image figure which shows the heat recovery device of Embodiment 2 of this invention Schematic configuration diagram of a conventional heat pump system for a vehicle air conditioner

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, the vehicle air conditioner includes an outside air and inside air blowing path and a heat pump system.

  In the outside air and inside air blowing path, the inside air is directed from the outside air inlet 1 for introducing outside air to the air conditioning outlet 2 for blowing the conditioned air into the vehicle, and from the inside air inlet 4 to the inside air outlet 7. An inside air discharge path 8 for discharging outside the vehicle, an outside air blowing means 9a for generating an air flow from the outside air introduction port 1 to the air conditioning outlet 2 in the supply air blowing path 3, and an inside air discharge from the inside air introduction port 4 to the inside air discharge path 8 An inside air blowing means 9b that generates an air flow toward the path 8 and a first in-vehicle heat exchanger 10 and a second in-vehicle heat exchanger 11 that cool or heat the air flowing through the supply air blowing path 3 are provided.

  The inside air inlet 4 is provided with a temperature sensor 5 as an inside air temperature detecting means for detecting the air temperature inside the vehicle and a temperature sensor 6 as an outside air temperature detecting means for detecting the air temperature outside the vehicle.

  As a heat source, an external heat exchanger 12 for exchanging heat with the outside air as a condenser during cooling operation and an evaporator during heating operation is provided in an air passage different from the air supply air passage 3, and the first in-vehicle heat exchanger 10, The heat pump which circulates a refrigerant | coolant between the 2nd in-vehicle heat exchanger 11, the external heat exchanger 12, and the compressor 13 is provided.

  Here, the configuration of the heat pump will be described.

  On the high-pressure refrigerant discharge side of the compressor 13, a four-way valve 14, a check valve 15 between the four-way valve 14 and the vehicle exterior heat exchanger 12, and a throttle valve 16 (between the vehicle exterior heat exchanger 12 and the first vehicle interior heat exchanger 10 ( As shown in the drawing, an expansion valve 16a and an electromagnetic valve 16b are incorporated), and a check valve 17 and a throttle valve 18 (an expansion valve 18a as shown in the drawing) A solenoid valve 18b is built in) to constitute a heat pump. Here, in the present embodiment, the temperature sensor 6 as the above-described outside air temperature detecting means is provided on the suction side of the outside heat exchanger 12.

  A heat recovery unit 19 that absorbs heat from the inside air flowing through the inside air discharge path 8 and dissipates heat to the outside air introduced from the outside air introduction port 1 is provided. The heat recovery unit 19 is a total heat exchanger that exchanges both sensible heat and latent heat.

  In the above configuration, each operation mode described in Table 1 will be described.

  First, the flow of the refrigerant during the cooling operation is as follows: compressor 13 → four-way valve 14 → check valve 15 → external heat exchanger 12 → throttle valve 16 → first in-vehicle heat exchanger 10 → compressor 13; No refrigerant flows through the exchanger 11.

  In such a refrigerant flow, the outside air is introduced from the outside air introduction port 1 by the operation of the outside air blowing means 9a, cooled to the inside air having a temperature lower than that of the outside air by the heat recovery device 19, and evaporated through the supply air blowing path 3. Cooled by the heat of vaporization of the refrigerant when passing through the first in-vehicle heat exchanger 10 acting as a cooler, passes through the second in-vehicle heat exchanger 11 where no refrigerant flows, and blows out cool air from the air conditioning outlet 2 to the windshield and the driver. . The blown cold air is circulated in the vehicle as inside air, and is warmed to the outside air by the heat recovery device 19 in the inside air discharge path 8 from the inside air introduction port 4 by the operation of the inside air blowing means 9b, and is discharged from the inside air discharge port 7 to the outside of the vehicle. The

  Thus, the internal air having a temperature lower than that of the outside air is not discharged as it is, but is discharged after the heat recovery device 19 exchanges heat with the outside air, so that the cooling load by the refrigerant in the first in-vehicle heat exchanger 10 is reduced and the compression is performed. The power consumption of the machine 13 can be reduced.

  Next, the refrigerant flow during the heating operation is as follows: compressor 13 → four-way valve 14 → second in-vehicle heat exchanger 11 → throttle valve 18 → outside heat exchanger 12 → electromagnetic valve 16b → compressor 13; No refrigerant flows through the exchanger 10.

  In such a refrigerant flow, the outside air is introduced from the outside air introduction port 1 by the operation of the outside air blowing means 9a, warmed to the inside air having a temperature higher than the outside air by the heat recovery device 19, and passes through the supply air blowing path 3, When the air passes through the first in-vehicle heat exchanger 10 where the air does not flow and passes through the second in-vehicle heat exchanger 11 acting as a condenser, it is heated by the condensation heat of the refrigerant, and warm air is blown from the air conditioning outlet 2 to the windshield and the driver. Blow out. The blown warm air becomes the inside air and circulates inside the vehicle, and is cooled to the outside air by the heat recovery device 19 in the inside air discharge path 8 from the inside air introduction port 4 by the operation of the inside air blowing means 9b, and discharged from the inside air discharge port 7 to the outside of the vehicle. Is done.

  Thus, the internal air having a temperature higher than that of the outside air is not discharged as it is, but is discharged after the heat recovery device 19 exchanges heat with the outside air, so that the heating load by the refrigerant in the second in-vehicle heat exchanger 11 is reduced and the compression is performed. The power consumption of the machine 13 can be reduced.

  In addition, when dehumidification is required such as the window being clouded during heating (first dehumidifying heating in Table 1), for example, the temperature of the outside air detected by the temperature sensor 6 as dew condensation detection means is the room temperature detected by the temperature sensor 5 (or the air conditioning in the vehicle). If the temperature is lower than the dew point temperature), the refrigerant flows through the first heat exchanger 10 after the vehicle heat exchanger 12 to act as an evaporator, and the outside air is cooled and dehumidified when passing through the first heat exchanger 10. By doing so, low-humidity warm air can be blown out from the air conditioning outlet 2 to the windshield and the driver.

  Here, the dew point temperature inside the vehicle changes depending on the humidity inside the vehicle, but by setting the general relative humidity 50 to 60% during heating, the dew point temperature inside the vehicle can be calculated. It can be judged whether there is cloudiness. Further, a humidity sensor (not shown) is provided in the vicinity of the temperature sensor 5 as the inside air temperature detecting means as a humidity detecting means for detecting the inside humidity of the car, and the dew point temperature inside the car is calculated using the detected humidity. It is possible to more accurately determine the presence or absence of cloudiness.

  At this time, if it is desired to eliminate the fogging of the window quickly, the amount of refrigerant evaporated in the first in-vehicle heat exchanger 10 may be increased more than in the outside heat exchanger 12. That is, by stopping the blower 20 for the vehicle exterior heat exchanger 12 or reducing the amount of blown air, the amount of refrigerant evaporated in the first in-vehicle heat exchanger 10 can be increased, and the dehumidifying capacity can be increased.

  Further, if the window is cloudy even after the above dehumidification (the second dehumidifying heating in Table 1), the outside air inlet 1 is closed by the damper 21, the damper 21 a of the outside air inlet 1 a is opened, and the outside air that does not pass through the heat recovery device 19. By introducing the outside air from the introduction port 1a, the humidity recovery from the inside air in the heat recovery device 19 is not performed, and therefore, hot air with lower humidity can be blown out from the air conditioning outlet 2 to the windshield and the driver.

  When the outside air is highly humid, that is, when the absolute humidity of the outside air is higher than the absolute humidity of the inside air, the damper 22 of the inside air introduction port 4, the damper 21 of the outside air introduction port 1, and the damper 21a of the outside air introduction port 1a are closed, Even when the inside air circulation is intermittently performed by opening the damper 22a of the normally closed inside air introduction port 4a, the dehumidifying load in the first in-vehicle heat exchanger 10 can be reduced, and wasteful power is not consumed. It is possible to suppress fogging of windows, particularly the windshield.

  As described above, according to such a configuration, the temperature sensor 5 is provided as the inside air temperature detecting means for detecting the air temperature inside the vehicle, and the temperature sensor 6 is provided as the outside air temperature detecting means for detecting the air temperature outside the vehicle. Using the temperature detected by the sensor and the set humidity or the humidity detected by the humidity sensor, the dew point temperature inside the car can be calculated, and by comparing with the outside air temperature, it is determined whether the windows, especially the windshield, are cloudy. Only when there is a possibility that the outside air is humid and the windshield may be fogged, the window can be dehumidified with the first in-vehicle heat exchanger and heated with the second in-vehicle heat exchanger. In particular, the effect of suppressing fogging of the windshield can be obtained.

(Embodiment 2)
Next, FIG. 2 shows another form of the heat recovery unit 19 described in the first embodiment.

  As shown in FIG. 2, the heat recovery unit 29 includes a sensible heat part 29 a that recovers only sensible heat (heat exchange) and a total heat part 29 b that recovers (heat exchange) total heat. Depending on the operation mode, the sensible heat part 29a and the total heat part 29b can be used properly.

  In the above configuration, the proper use of the heat recovery device 29 in each operation mode shown in Table 1 will be described.

  Since it is possible to reduce the cooling load when the humidity of the outside air is not put in the vehicle during the cooling operation, it is preferable to use only the total heat part 29b. When the outside air is low humidity, both the sensible heat part 29a and the total heat part 29b are used. May be used.

  During heating operation, when the outside air is low humidity, it is preferable to use both the sensible heat portion 29a and the total heat portion 29b. When the outside air is high humidity or when the dehumidification is necessary such as clouding of the window (the first in Table 1) It is preferable to use only the sensible heat portion 29a. That is, the heat recovery device 29 can be used also in the second dehumidifying heating in Table 1, and the internal air having a temperature higher than the outside air is not discharged as it is, but is discharged after the heat recovery device 19 exchanges heat with the outside air. Since it did in this way, the heating load by the refrigerant | coolant in the 2nd vehicle interior heat exchanger 11 reduces, and the power consumption of the compressor 13 can be reduced.

  In the present embodiment, the sensible heat part 29a and the total heat part 29b are represented by an image as shown in FIG. 2, but a damper for switching the air path is required to use the sensible heat part 29a and the total heat part 29b properly. Become.

  In addition, when the flow is made to flow through both the sensible heat portion 29a and the total heat portion 29b or when only one of them is flowed, the air volume also changes due to the difference in pressure loss. It is preferable to flow in both.

  Since the vehicle air conditioner according to the present invention recovers heat from the air-conditioned vehicle interior and can bring the outside air to be introduced closer to the vehicle interior environment, it can reduce the air conditioning load in the vehicle. It is useful as a vehicle air conditioner that can heat the passenger compartment used in electric vehicles, hybrid vehicles, and the like where it is difficult to obtain a heat source.

DESCRIPTION OF SYMBOLS 1, 1a Outside air introduction port 2 Air-conditioning blower outlet 3 Supply air ventilation path 4, 4a Inside air introduction port 5, 6 Temperature sensor 7 Inside air discharge port 8 Inside air discharge path 9a Outside air blowing means 9b Inside air blowing means 10 1st vehicle interior heat exchanger 11 Second heat exchanger 12 Inside heat exchanger 13 Compressor 14 Four-way valve 15, 17 Check valve 16, 18 Throttle valve 16a, 18a Expansion valve 16b, 18b Electromagnetic valve 19, 29 Heat recovery device 20 Blower 21, 21a, 22, 22a Damper 29a Sensible heat part 29b Total heat part

Claims (5)

An air supply air passage from an outside air inlet that introduces outside air to an air conditioning outlet that blows out conditioned air into the vehicle;
An inside air discharge path from an inside air introduction port for introducing inside air to an inside air discharge port for discharging inside air to the outside of the vehicle,
An outside air blowing means for generating an air flow from the outside air inlet to the air conditioning outlet in the supply air passage;
An inside air blowing means for generating an air flow from the inside air inlet to the inside air outlet in the inside air discharge path;
A first in-vehicle heat exchanger and a second in-vehicle heat exchanger for cooling or heating the air flowing through the air supply air passage;
An external heat exchanger that exchanges heat with outside air as a condenser during cooling operation and an evaporator during heating operation;
A heat pump that circulates refrigerant between the first in-vehicle heat exchanger, the second in-vehicle heat exchanger, and the external heat exchanger and the compressor;
A heat recovery unit that recovers heat by exchanging heat between the inside air flowing through the inside air discharge path and the outside air introduced from the outside air inlet;
It has an inside air temperature detecting means for detecting the air temperature inside the vehicle and an outside air temperature detecting means for detecting the air temperature outside the car,
A vehicle air conditioner that controls dehumidification during heating operation using the temperature detected by the inside air temperature detecting means and the temperature detected by the outside air temperature detecting means. The vehicle air conditioner according to claim 1, further comprising humidity detection means for detecting the humidity inside the vehicle. The vehicle air conditioner according to claim 1 or 2, wherein an outside air inlet that does not pass through the heat recovery unit is provided. The vehicle air conditioner according to any one of claims 1 to 3, wherein the heat recovery unit recovers total heat and / or sensible heat. The vehicle air conditioner according to any one of claims 1 to 4, wherein a switching damper is provided at the inside air introduction port to switch between inside air circulation and outside air introduction.

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