JPH08268035A - Air conditioner for electric vehicle - Google Patents

Abstract

PURPOSE: To conduct air blowing at a desired air blowing temperature promptly at the time of heating, regardless of a sudden change in an air conditioning condition. CONSTITUTION: By controlling driving of inside/outside air switching damper 24 based on the temperature detected by an outside air sensor 18, an air conditioner controller 34 selects an outside air introduction mode if the temperature is beyond a prescribed threshold, and an inside air circulating mode if not. The air conditioner controller 34 energizes an electric heater 27 if outside air temperature is smaller than the prescribed threshold value with the outside air introduction mode selected. The air conditioner controller 34 corrects the rotational speed of a blower 25 downwards until the temperature of air passing through a sub condenser 13, detected by a temperature sensor 28, exceeds the prescribed threshold value. The air conditioner controller 34 corrects the rotational speed of the blower 25 downwards until the pressure of a heat exchange medium discharged from a compressor 11 detected by a pressure sensor 17 exceeds the prescribed threshold value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for an electric vehicle, and more particularly, to an air conditioner for an electric vehicle equipped with a sub-capacitor capable of effectively obtaining a desired blowing temperature in a short time.

[0002]

2. Description of the Related Art Conventionally, there is an air conditioner for an electric vehicle provided with a sub-capacitor, which has, for example, a configuration shown in FIG. 6 (Japanese Patent Laid-Open No. 3-345950, Japanese Patent Laid-Open No. 6-92130, etc.). reference).

That is, the heat pump cycle is equipped with a compressor 1, a three-way valve 2, a main condenser 3, a check valve 4, a sub condenser 5, an interior heat exchanger 6, and an expansion valve 7, and the sub condenser 5 and the interior heat The exchange 6 is
It is housed in a unit 9 arranged in the front part of the vehicle.

In the electric vehicle air conditioner having such a structure, when the cooling mode is selected, the heat exchange medium discharged from the compressor 1 passes through the three-way valve 2 as shown by a broken arrow in FIG. Flow into the main condenser 3 and the sub-condenser 5, and after radiating the heat, the heat is absorbed by the heat exchanger 6 inside the vehicle. Also, when the heating mode is selected,
The three-way valve 2 is switched, and the heat exchange medium discharged from the compressor 1 passes through the bypass line 8 without passing through the main condenser 3 via the three-way valve 2 as shown by a solid arrow in FIG. After flowing into the condenser 5 and radiating the heat to heat the passing air, the inside heat exchanger 6 absorbs heat to dehumidify.

[0005]

However, in the conventional air conditioner for an electric vehicle equipped with the sub-condenser 5, the inside air or the outside air introduced into the unit 9 is
It is dehumidified by the heat exchanger 6 inside the vehicle and the sub-condenser 5
The heating is a dehumidification heating with dehumidification as it is heated by. Therefore, when the inside air circulation mode is switched to the outside air introduction mode when the outside air temperature is low, the temperature of the air passing through the heat exchanger inside the vehicle is drastically lowered, and there is a problem that frost forms on the surface. Further, in this case, there is a problem in that heating by the sub-capacitor cannot be performed in time, a desired air temperature cannot be obtained, and an occupant feels uncomfortable.

In view of the above problems, the present invention provides an air conditioner for an electric vehicle equipped with a sub-capacitor capable of quickly blowing air at a desired air blowing temperature during dehumidifying heating, regardless of a sudden change in air conditioning conditions. The purpose is to do.

[0007]

To achieve the above object, in the present invention, a heat pump cycle having a compressor, a main condenser, a sub-condenser, an expansion valve and a heat exchanger inside the vehicle, in which a heat exchange medium circulates, Equipped with an inside / outside air switching damper that selects the inside air circulation mode or outside air introduction mode.When dehumidifying and heating, the inside air or outside air is cooled and dehumidified by the heat exchanger inside the vehicle, and the heating capacity of the sub-condenser is increased to the inside of the vehicle. While supplying warm air, while cooling, cool the inside air or outside air with a heat exchanger inside the vehicle,
In an electric vehicle air conditioner that suppresses heating in a sub-capacitor and supplies cool air to the inside of the vehicle, an outside air sensor that detects the outside air temperature and a temperature detected by the outside air sensor during dehumidification heating are set to a predetermined value. If it exceeds the threshold value, the outside air introduction mode is selected, and if it does not exceed the threshold value, the inside air circulation mode is selected.

A sub-condenser is provided on the downstream side of the heat exchanger inside the vehicle, and an electric heater for heating passing air is provided, and the air conditioner control means selects the outside air introduction mode during dehumidification heating. The electric heater may be energized if the temperature detected by the outside air sensor is equal to or lower than a predetermined threshold value.

The air conditioner control means includes a temperature sensor for detecting the temperature of air passing through the sub-condenser.
During dehumidification heating, the rotation speed of the blower may be corrected downward until the temperature detected by the temperature sensor exceeds a predetermined threshold value.

A pressure sensor for detecting the pressure of the heat exchange medium immediately after being discharged from the compressor is provided, and the air conditioner control means, during dehumidification heating, until the pressure detected by the pressure sensor exceeds a predetermined threshold value. The rotation speed of the blower may be corrected downward.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an air conditioner for an electric vehicle according to the first embodiment. This air conditioner for an electric vehicle has a heat pump cycle in which a heat exchange medium discharged from a compressor 11 circulates in the order of a main condenser 12, a sub condenser 13, an expansion valve 14, an in-vehicle heat exchanger 15, and a compressor 11. ing.

In the compressor 11, a built-in motor (not shown) is rotationally driven by electric power supplied from the compressor driving device 16, and the sucked heat exchange medium is discharged in a high temperature / high pressure state. A pressure sensor 17 is provided on the discharge side pipe a of the compressor 11 to detect the pressure of the heat exchange medium.

The main condenser 12, the sub condenser 13, and the heat exchanger 15 on the inside of the vehicle have a structure in which flat tubes and corrugated fins are laminated and integrated, and when the heat exchange medium flows while meandering through the flat tubes. , Exchanges heat with the air passing through the fins.

The main condenser 12 is attached to the front portion of the vehicle. Also, this main capacitor 1
An outside air sensor 18 is provided in the front part of 2 to detect the outside air temperature.

In front of the main condenser 12, A
A DD fan 19 is provided, and a movable shutter 20 is attached in front of the DD fan 19 so that traveling wind can be passed or blocked. The ADD fan 19 is rotated or stopped by a control signal from the fan drive device 21, and the movable shutter 20 allows or blocks the traveling wind from being blown to the main condenser 12 by the control signal from the shutter drive device 22. The movable shutter 20 is, for example, a louver or an electric shutter driven by a motor used in armor doors,
It is possible to use a structure in which a thin plate made of metal or the like is wound around a rotary shaft that is rotated by a driving means such as a motor.

The sub-condenser 13 and the vehicle interior heat exchanger 15 are arranged in a unit 23 at the front of the vehicle interior. Inside the unit 23, outside, inside / outside air switching damper 24, blower 25, mix damper 26, electric heater 2
7 etc. are provided respectively. A temperature sensor 28 is provided near the downstream side of the vehicle interior heat exchanger 15 to detect the temperature of passing air.

The inside / outside air switching damper 24 is provided at the most upstream portion of the unit 23, and is configured to block either the inside air suction port 30a or the outside air suction port 30b by the suction port switching device 29.

The blower 25 is provided on the downstream side of the inside / outside air switching damper 24 and on the upstream side of the vehicle interior heat exchanger 15, and is rotated by a blower motor 25a driven on the basis of a signal from a blower driving device 31. The unit 23 is driven and introduces the inside air or the outside air selected by the inside / outside air switching damper 24 into the unit 23.

The mix damper 26 is provided on the downstream side of the vehicle interior heat exchanger 15. The sub-condenser 13 and the electric heater 27 are sequentially arranged in one of the flow paths divided by the mix damper 26.
Then, by adjusting the opening degree of the mix damper 26 by the opening degree adjusting device 32, the sub-condenser 13
Also, the flow rate of air passing through the electric heater 27 is adjusted. Energization of the electric heater 27 is performed via an energization adjusting device 33.

In the blower unit (not shown) arranged in the most downstream portion of the unit 23, the blower mode can be selected by opening and closing each outlet.

The air conditioner control device 34, based on the temperature detected by the outside air sensor 18 and the temperature sensor 28, the pressure detected by the pressure sensor 17, and the like, the suction port switching device 29, the blower drive device 31, and the opening adjustment device 32. , Electricity amount adjusting device 33
A control signal is output to control the rotational position of the inside / outside air switching damper 24, the rotation speed of the blower 25, the opening degree of the mix damper 26, and the amount of electricity supplied to the electric heater 27 during dehumidifying and heating.

Next, the operation of the air conditioner for an electric vehicle equipped with the sub-capacitor 13 having the above-mentioned configuration will be described with reference to FIG.
It will be described according to the flowchart shown in FIG.

First, in step S1, the inside and outside conditions of the vehicle input from the outside air sensor 18 and the like are read, and then in step S2, the target air blowing temperature and the target air blowing amount are calculated based on the read inside and outside conditions of the vehicle. And step S3
Then, the rotational position of the inside / outside air switching damper 24, the rotation speed of the blower 25, the drive frequency of the compressor 11, and the opening degree of the mix damper 26 are determined in accordance with the target blown air temperature and the target blown air amount, and the air conditioning in the vehicle is started.

When cooling the inside of the vehicle, the heat exchange medium discharged from the compressor 11 is sufficiently radiated by the main condenser 12, and is vaporized by the inside heat exchanger 15 from the sub condenser 13 through the expansion valve 14. As a result, the air passing through the vehicle interior heat exchanger 15 is dehumidified and cooled. Further, by rotating the mix damper 26 to suppress the amount of air blown to the sub-capacitor 13 side, the cold air is blown inside the vehicle as it is.

On the other hand, when dehumidifying and heating the inside of the vehicle, the ADD fan 19 is stopped and the movable shutter 20 is driven so that the traveling wind does not directly hit the main condenser 12. Thereby, the heat dissipation in the main capacitor 12 is suppressed, and the heating capacity in the sub capacitor 13 is improved. Further, the mix damper 26 is rotated to increase the amount of air blown to the sub-capacitor 13 side, so that warm air is blown to the inside of the vehicle.

Although air conditioning is performed in the vehicle as described above, if it is determined in step S4 that dehumidifying heating is performed, drive control is further performed in step S5 in accordance with the flowchart of FIG. 3 described below for the inside / outside air switching damper 24.

That is, the inside / outside air switching damper 24 is basically drive-controlled by an occupant operating a switch (not shown) to select either the outside air introduction mode or the inside air circulation mode. Then, the outside temperature T
Drive control is further performed according to the _out according to the flowchart of FIG.

First, in step S11, the outside air temperature T _out
Is lower than the low temperature-side set temperature T _L (for example, 15 ° C.). When T _out < _TL , the inside heat exchanger 15 may be frosted in the outside air introduction mode, and it can be inferred that the heating inside the vehicle is insufficient only by heating the sub-condenser 13. Therefore, step S12
Then, when the inside air circulation mode is selected, the outside air introduction mode is selected as it is, and when the outside air introduction mode is selected, the outside air suction port 30b is closed by the inside / outside air switching damper 24 to forcibly switch to the inside air circulation mode. Then, it transfers to step S13. If T _out < _TL is not satisfied, the process directly proceeds to step S13.

In step S13, it is determined whether the outside air temperature T _out is higher than the high temperature side preset temperature T _H (for example, 20 ° C.). If T _out > T _H , there is no fear of frost formation on the heat exchanger 15 inside the vehicle, so that the outside air introduction mode can be selected and the process returns to the flowchart of FIG. 2 to perform air conditioning in the vehicle as usual. Therefore, although the outside air introduction mode is selected, when the inside air circulation mode is forcibly switched to in step S12, the outside air temperature T _out rises and T _out > _TH is satisfied. At that time, it will switch to the outside air introduction mode.

On the other hand, if T _out > T _H is not satisfied, the current mode is maintained and the process returns to the flowchart of FIG.

As described above, when the outside air temperature T _out is lower than the low temperature side set temperature T _L , the inside air circulation mode is forcibly selected, so that the inside heat exchanger 15 is frosted. It is possible to avoid switching to the outside air introduction mode when the property is high. Further, since it is possible to switch to the outside air introduction mode only when the outside air temperature T _out is higher than the high temperature-side set temperature T _H , there is no fear of frost forming on the heat exchanger 15 inside the vehicle, and heating by the sub-condenser. It is not necessary to increase the capacity so much, and it is possible to suppress the power consumption in the compressor 11.

The air conditioner for an electric vehicle according to the second embodiment has the same configuration as that of the first embodiment shown in FIG. 1, and the air conditioning control is the energization control to the electric heater 27 in step S5 in the flowchart of FIG. Is performed according to the flowchart shown in FIG.

That is, in the second embodiment, first, in step S21, it is determined whether or not the outside air introduction mode is selected. If the inside air circulation mode is used instead of the outside air introduction mode, the target air blowing temperature can be obtained only by heating the sub-condenser 13.
The process returns to the flowchart shown in FIG. 2 through step S25. If it is the outside air circulation mode, step S2
In step 2, it is determined whether the outside air temperature T _out is lower than the low temperature side preset temperature T _L.

If T _out <T _L is satisfied, the target blast temperature cannot be obtained even if the mix damper 26 is rotated to heat all the air by the sub-condenser 13. In step S23, the electric heater 27 is energized to start heating not only the sub-capacitor 13 but also the electric heater 27, and the process proceeds to step S24.

If T _out <T _L is not satisfied, the heating by the sub-condenser 13 is sufficient to obtain the desired blast temperature. Therefore, the electric heater 27 is not energized and the process directly proceeds to step S24. Transition.

In step S24, it is determined whether the outside air temperature T _out is higher than the high temperature side preset temperature T _H (for example, 20 ° C.). If T _out > _TH is satisfied, step S25
After stopping the power supply to the electric heater 27,
_{If out} > _TH is not satisfied, the flow returns to the flowchart shown in FIG.

As described above, when the outside air introduction mode is selected during dehumidification and heating, the insufficient heating of the sub-capacitor 13 is compensated for by the electric heater 27 even when the outside air temperature is low, so that the desired air flow is always maintained. The temperature can be obtained. For example, if the humidity inside the vehicle rises and the window glass is apt to fog, it is possible to effectively remove the fog by introducing outside air having a lower humidity than the inside air, and the electric heater 27 blows air. It is possible to prevent the temperature from dropping.

The electric heater 27 is preferably capable of switching the heating capacity. For example, when the outside air introduction mode is selected, the heating capacity is increased according to the degree of decrease in the outside air temperature. Is desirable.

The electric vehicle air conditioner according to the third embodiment also has the same configuration as that of the first embodiment shown in FIG. 1, except that the air conditioning control is performed according to the flow chart shown in FIG. It is characterized by control.

In the air conditioning control according to the third embodiment, first, in step S31, various conditions inside and outside the vehicle such as the outside air temperature, the inside air temperature, and the amount of solar radiation are read, and in step S32, the target blown air temperature based on the inside and outside conditions of the vehicle. After calculating, step S3
Move to 3.

In step S33, it is determined whether the temperature T _E detected by the temperature sensor 28 is lower than the low temperature set temperature T _L (eg, 26 ° C.).

When T _E <T _L , even if the mix damper 26 is rotated so that all the air passes through the sub-capacitor 13 side during dehumidifying and heating, the sub-capacitor 13 alone is sufficient for heating. When it is determined that the target air flow rate is not present, the target air flow rate is corrected downward and calculated in step S34, and then the process proceeds to step S38. Here, the temperature sensor 28 plays a role of detecting the temperature of the air passing through the sub-condenser 13. However, instead of the temperature sensor 28,
Of course, the temperature of the air passing through the sub-capacitor 13 may be directly detected by providing another temperature sensor near the downstream side of the sub-capacitor 13. On the other hand, if T _E < _TL , then step S35 is performed.
Therefore, the detected temperature T _E is the high temperature side preset temperature T _H (for example, 35
℃) to determine whether it is higher than.

When T _E > T _H is not satisfied, it is further determined in step S37 whether or not the target air flow rate is calculated for the first time, that is, immediately after the heating operation is started. If it is the first time, the target air flow rate is calculated in step S36, and if it is the second time or later, the process directly proceeds to step S38. It should be noted that the target air flow rate calculated in step S36 is, as in the conventional case, a value suitable for setting the temperature inside the vehicle together with the target air flow temperature. On the other hand, if T _E > T _H , the same as above, through step S36 to step S3
Move to 8.

In step S38, when the detected temperature T _E (air temperature passing through the sub-condenser 13) is lower than the set temperature during dehumidification heating, the blower 25 is rotated according to the value corrected downward from the normal target air flow rate. Then, the air flow rate is suppressed, and if not, an appropriate air flow rate is obtained according to the normal target air flow rate.

In the third embodiment shown in FIG. 5, the blower 25 is driven and controlled on the basis of the temperature T _E detected by the temperature sensor 28, but as the fourth embodiment, the pressure sensor 17 detects it. It may be performed based on the discharge pressure P of the heat exchange medium.

The drive control of the blower 25 based on the discharge pressure P is basically performed according to the flow chart shown in FIG. In this case, in steps S33 and S35, the discharge pressure P is, whether less than the low-pressure side setting pressure P _L, it suffices to determine whether greater or not than the high-pressure side setting pressure P _H.

According to this, while the detected pressure P of the heat exchange medium is smaller than the set pressure P _L on the low pressure side, the blower 2 is forcibly forced.
Since the amount of air blown by 5 is adjusted downward, a large amount of cold air does not blow out to the inside of the vehicle when the sub-condenser 13 cannot sufficiently heat the air, and it is possible to minimize problems that the occupant suffers.

[0049]

As is apparent from the above description, according to the present invention, in an air conditioner for an electric vehicle equipped with a sub-capacitor, an inside / outside air switching damper, an auxiliary heater, or a blower is responded to a sudden change in air conditioning conditions. Since it is driven and controlled, the desired blowing temperature can be efficiently obtained in a short time.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an air conditioner for an electric vehicle according to an embodiment.

FIG. 2 is a flowchart showing air conditioning control of the electric vehicle air conditioner according to the present embodiment.

FIG. 3 is a flowchart showing an example of the drive control process of FIG.

FIG. 4 is a flowchart showing another example of the drive control process of FIG.

FIG. 5 is a flowchart showing another example of the drive control process of FIG.

FIG. 6 is a schematic diagram of an air conditioner for an electric vehicle according to a conventional example.

[Explanation of symbols]

 11 Compressor 13 Sub-condenser 15 Heat exchanger inside the vehicle 17 Pressure sensor 18 Outside air sensor 24 Inside / outside air switching damper 25 Blower 27 Electric heater 34 Air conditioner controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideaki Nishii Inventor Hideaki Nishii 5658 Yoshikawa, Hachihonmatsu-cho, Higashihiroshima City, Hiroshima Prefecture Japan Climate Systems Co., Ltd.

Claims (4)

[Claims] 1. A heat pump cycle having a compressor, a main condenser, a sub condenser, an expansion valve and a heat exchanger on the inside of the vehicle, in which a heat exchange medium circulates, and an inside / outside air switching damper for selecting an inside air circulation mode or an outside air introduction mode. In addition to cooling and dehumidifying the inside air or the outside air with the heat exchanger inside the vehicle during dehumidification and heating, the heating capacity of the sub-condenser is increased to supply warm air to the inside of the vehicle, while during cooling,
In an air conditioner for an electric vehicle that cools inside air or outside air with a heat exchanger inside the vehicle and suppresses heating by a sub-condenser to supply cool air to the inside of the vehicle, an outside air sensor that detects an outside air temperature, and During dehumidification heating, the outside air introduction mode is selected if the temperature detected by the outside air sensor exceeds a predetermined threshold value, and if not, the inside air circulation mode is selected, and an air conditioner control means is provided. Air conditioners for electric vehicles. 2. A heat pump cycle having a compressor, a main condenser, a sub-condenser, an expansion valve, and a heat exchanger inside the vehicle, and a heat exchange medium circulating. While cooling and dehumidifying, the heating capacity of the sub-condenser is increased to supply warm air to the inside of the vehicle, while during cooling, the inside air or outside air is cooled by the heat exchanger inside the vehicle and the heating of the sub-condenser is suppressed. In an air conditioner for an electric vehicle configured to supply cool air to the inside of a vehicle, an outside air sensor that detects the outside air temperature and a sub-condenser are provided downstream of the inside heat exchanger to heat passing air. When the outside air introduction mode is selected during the dehumidifying and heating with the electric heater, if the temperature detected by the outside air sensor is equal to or lower than a predetermined threshold value, the electric heater An air conditioner for an electric vehicle, comprising: an air conditioner control unit that energizes the data. 3. A heat pump cycle having a compressor, a main condenser, a sub-condenser, an expansion valve, and a heat exchanger on the inside of the vehicle, wherein a heat exchange medium circulates. While cooling and dehumidifying, the heating capacity of the sub-condenser is increased to supply warm air to the inside of the vehicle, while during cooling, the inside air or outside air is cooled by the heat exchanger inside the vehicle and the heating of the sub-condenser is suppressed. In an air conditioner for an electric vehicle adapted to supply cool air to the inside of the vehicle, a temperature sensor for detecting the temperature of the air passing through the sub-condenser, and a temperature detected by the temperature sensor during dehumidification heating exceeds a predetermined threshold value. An air conditioner for an electric vehicle, comprising: an air conditioner control unit that adjusts the rotation speed of the blower downward. 4. A heat pump cycle having a compressor, a main condenser, a sub-condenser, an expansion valve, and a heat exchanger on the inside of the vehicle, wherein a heat exchange medium circulates. During dehumidification and heating, the inside or outside air is exchanged by the heat exchanger on the inside of the vehicle. While cooling and dehumidifying, the heating capacity of the sub-condenser is increased to supply warm air to the inside of the vehicle, while during cooling, the inside air or outside air is cooled by the heat exchanger inside the vehicle and the heating of the sub-condenser is suppressed. In an air conditioner for an electric vehicle configured to supply cool air to the inside of the vehicle, a pressure sensor for detecting the pressure of the heat exchange medium immediately after being discharged from the compressor, and a pressure detected by the pressure sensor during the dehumidifying and heating. Until the temperature exceeds a predetermined threshold, the air conditioner control means for downwardly adjusting the rotation speed of the blower is provided.