JPH0596931A - Vehicle air-conditioning device - Google Patents

Abstract

PURPOSE:To provide a vehicle air-conditioning device which can prevent a front windshield pane from being fogged up during changeover from cooling operation into heating operation, which can prevent lowering of the temperature of blow-off air flowing into the passenger compartment even though air is led through heater core when the temperature of engine cooling water is low, and which can effectively use the heat of air which has passed through the heater core. CONSTITUTION:An evaporator 6, a heater core 14 and a capacitor 4 are laid in a duct in that order so that dehumidification can be always made so that it is possible to prevent a front windshield pane from being fogged up. Further, even though the temperature of engine cooling water is low so that the temperature having passed through a heater core is low, it is raised finally by a condenser 4, and accordingly, the temperature of blow-off air flowing into a passenger compartment becomes higher. Due to the provision of the condenser 4 downstream of the heater core 14, the temperature of the air is raised in the condenser 4 after it is raised more or less by the heater core 14. Accordingly, even slight heat owned the air having passed through the heater core 14 is effectively used so as to reduce the heating load to the condenser4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner for air conditioning the inside of a vehicle using a heat pump, and is effective in a hybrid car which is an electric vehicle using an engine as an auxiliary power source.

[0002]

2. Description of the Related Art When cooling a passenger compartment, the indoor heat exchanger functions as an evaporator to blow cold air into the passenger compartment, and when the passenger compartment is heated, the heat exchanger functions as a condenser. A so-called heat pump, which blows out warm air into a room, has been conventionally known. Further, in view of the fact that the heat pump alone cannot sufficiently heat the interior of the vehicle when the outside air temperature is considerably low, JP-A-60-219114.
As disclosed in the publication, a heater is provided downstream of an indoor heat exchanger, and air is ventilated through the indoor heat exchanger and the heater functioning as a condenser to enhance the vehicle interior heating capacity. An automotive air conditioner has already been developed.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the technique disclosed in 0-219114, since the heater is disposed downstream of the indoor heat exchanger, if the vehicle interior heating is performed when the engine cooling water flowing inside the heater is not warmed, There is a problem that the air heated through the indoor heat exchanger functioning as a condenser is cooled by passing through the heater.

As a method of solving the above problem, a method of preventing air from passing through the heater, that is, a method of bypassing the heater by air can be considered. However, considering the fact that if the engine cooling water is warm even a little, the air after passing through the heater will have some heat, I would like to make effective use of this slight amount of heat. The desire to arise also arises.

Further, in the technique disclosed in JP-A-60-219114, since the same indoor heat exchanger functions as an evaporator or a condenser, it functions as an evaporator during cooling operation. Moisture generated on the surface of the functioning indoor heat exchanger was evaporated by the indoor heat exchanger functioning as a condenser during the heating operation, and was blown into the vehicle interior. Then, there is a problem in that the moisture causes the windshield in the vehicle interior to be fogged and obstructs the occupant's view.

Therefore, according to the present invention, when the cooling operation is switched to the heating operation, the windshield is not fogged, and even if the air is ventilated through the heater core when the engine cooling water temperature is low, the air blown into the passenger compartment is prevented. It is an object of the present invention to provide an air conditioner for a vehicle that does not lower the temperature and can effectively use a slight amount of heat of the air after ventilating the heater core.

[0007]

To achieve the above object, in claim 1, a duct forming an air-conditioning air passage to a vehicle cabin, and a blower for blowing air into the vehicle cabin through the duct, An evaporator that is disposed in the duct and that dehumidifies and cools the air in the duct by removing heat from the air in the duct by the refrigerant flowing inside the duct; and on the downstream side of the evaporator in the duct. A condenser arranged to heat the air in the duct by radiating the refrigerant flowing through the condenser, and a compressor connected between the evaporator and the condenser to perform compression discharge of the refrigerant. An outdoor heat exchanger disposed outside the duct for exchanging heat between the refrigerant flowing inside itself and the air outside the duct, and the outdoor heat exchanger functioning as an evaporator or functioning as a condenser To let A switching means for switching, an expansion means arranged between the evaporator and the condenser for decompressing and expanding the refrigerant, and arranged in the duct on the downstream side of the evaporator and on the upstream side of the condenser. The gist of the present invention is a vehicle air conditioner that is provided with a heater that heats the air by using engine cooling water as a heat source.

In order to achieve the above object, in claim 2, a duct forming an air-conditioning air passage to the vehicle compartment, a blower for blowing air into the vehicle compartment through the duct, and a duct inside the duct. An evaporator in the duct, which is arranged and cools the air in the duct by dehumidifying and cooling the refrigerant flowing in the inside of the duct by removing heat from the air in the duct, and on the downstream side of the evaporator in the duct. The condenser in the duct, which is disposed and heats the air in the duct by radiating the refrigerant flowing through itself, is connected between the evaporator and the condenser, and compresses and discharges the refrigerant. A compressor that performs the operation, an outdoor evaporator that is disposed outside the duct, and that causes the refrigerant flowing inside itself to take heat from the air outside the duct to give heat to the refrigerant, and the outdoor evaporator. The endothermic A heat absorption amount adjusting means, an outdoor condenser arranged outside the duct for radiating the refrigerant flowing inside itself, and a heat radiation amount adjusting means for adjusting the heat radiation amount of the outdoor condenser. An expansion means connected between the evaporator in the duct and the condenser in the duct for decompressing and expanding the refrigerant, and a downstream side of the evaporator in the duct and upstream of the condenser in the duct. The gist is a vehicle air conditioner, which is disposed in the duct on the side, and is composed of a heater that heats the air by using engine cooling water as a heat source.

[0009]

According to the first aspect of the present invention, one heat exchanger in the duct does not perform both functions of the evaporator and the condenser, but the evaporator and the condenser are separately provided in the duct.
Since the evaporator only functions as an evaporator, the water generated on the surface of the evaporator does not evaporate due to the evaporator functioning as a condenser. Therefore, the windshield does not become cloudy.

Further, since the evaporator, the heater, and the condenser are arranged in this order in the duct, the air passed through the heater is blown directly into the passenger compartment when the engine cooling water temperature is low. There is no. That is, since the air is heated to a high temperature by the condenser provided at the most downstream side in the duct and is then blown, warm air is blown into the passenger compartment.

Further, a heater is arranged on the upstream side of the condenser, and even if the engine cooling water temperature is low, the temperature of the air is raised to some extent by passing air through the heater,
Then, the condenser heats the air to a predetermined temperature. Therefore, the heating load on the condenser is somewhat reduced.

In the second aspect, the heat exchange state between the evaporator and the condenser in the duct can be arbitrarily controlled by adjusting the heat absorption amount adjusting means and the heat radiation amount adjusting means. as a result,
Air conditioning in the duct becomes possible.

Further, as in the first aspect, it is possible to prevent the windshield from fogging and to prevent the air heated by the condenser in the duct from being cooled by the cold heater.

[0014]

As described above, in the vehicle air conditioner according to the present invention, the windshield does not become fogged during the switching from the cooling operation to the heating operation, and the inside of the vehicle compartment is protected regardless of the engine cooling water temperature. Since the temperature of the blowing air does not drop, safe and stable air conditioning in the vehicle interior can be performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the entire vehicle air conditioner in the first embodiment.

In FIG. 1, reference numeral 1 is a compressor as a compressor for compressing a refrigerant flowing in the direction of the arrow in the drawing to bring it into a high temperature and high pressure state and discharging the refrigerant in the direction of the arrow. Reference numeral 2 is a first four-way valve as a switching unit that switches the direction in which the refrigerant flows by electromagnetic control, and reference numeral 3 is a second four-way valve that also serves as a switching unit that switches the direction in which the refrigerant flows by electromagnetic control. Reference numeral 4 denotes a condenser as a condenser that heats the air by passing air through the gas refrigerant that has become high temperature and high pressure in the compressor 1 by flowing through the inside, The condenser 4 is arranged inside the duct 11.

Reference numeral 5 denotes a capillary tube as an expansion means made of a thin tube, which is spirally wound. The refrigerant is gradually decompressed as it flows through the capillary tube 5. Reference numeral 6 denotes an evaporator as an evaporator that cools the cold liquid refrigerant decompressed by the capillary tube 5 by flowing through the inside thereof, and draws heat from the air by passing air through the cooled itself to cool the air. The evaporator 6 is arranged in the duct 11. Reference numeral 7 is an evaporation pressure regulator for preventing the evaporator 6 from frosting.

An outdoor heat exchanger 8 exchanges heat between the refrigerant flowing inside and the outside air. Outdoor heat exchanger 8
Functions as an evaporator that removes heat from the outside air by switching the first four-way valve 2 and the second four-way valve 3,
It functions as a condenser that radiates heat to the outside air. That is, if the first four-way valve 2 and the second four-way valve are controlled so that the refrigerant flows through the outdoor heat exchanger 8 and the compressor 1 in this order, the outdoor heat exchanger 8 functions as an evaporator. If the first four-way valve 2 and the second four-way valve 3 are controlled so that the refrigerant flows through the compressor 1 and the outdoor heat exchanger 8 in this order, the outdoor heat exchanger 8 functions as a condenser. Become.

Reference numeral 9 is an outdoor heat exchanger fan for adjusting the amount of heat exchange between the refrigerant inside the outdoor heat exchanger 8 and the outside air. That is, if the outdoor heat exchanger fan 9 is driven weakly, the amount of air passing through the outdoor heat exchanger 8 decreases, so the amount of heat that can be exchanged by the outdoor heat exchanger 8 decreases. Further, when the outdoor heat exchanger fan 9 is strongly driven, the amount of air passing through the outdoor heat exchanger 8 increases, so that the amount of heat that can be exchanged by the outdoor heat exchanger 8 increases.

Reference numeral 10 denotes an accumulator for accumulating a liquid refrigerant therein, discharging only the gas refrigerant, and causing the compressor 1 to compress only the discharged gas refrigerant. 11
Is a duct for accommodating the condenser 4 and the evaporator 6. Reference numeral 12 denotes an inside / outside air switching damper that switches whether the air blown into the vehicle compartment is introduced from outside air or inside air. Reference numeral 13 is a blower for blowing air introduced from inside air or outside air into the vehicle compartment through the duct 1.

Reference numeral 14 denotes a heater core as a heater for heating the air after passing through the evaporator 6, which is arranged in the duct 11 on the downstream side of the evaporator 6 and the upstream side of the condenser 4. The heater core 14 uses, as a heat source, engine cooling water that cools an engine 15 that is used as an auxiliary power source for the vehicle or for charging a battery generator (not shown).

Reference numeral 16 is a first air mix damper that adjusts the amount of air passing through the heater core 14 and the amount of air passing through the first bypass passage 17 to adjust the temperature of the air blown into the passenger compartment. Reference numeral 18 is a second air mix damper that adjusts the amount of air passing through the condenser 4 and the amount of air passing through the second bypass passage 19 to adjust the temperature of the air blown into the vehicle interior.

Next, the operation of the above configuration will be described. When cooling the vehicle interior, the refrigerant that has flowed out of the compressor 1 in the direction of the arrow in the figure flows through the outdoor heat exchanger 8, the condenser 4, the capillary tube 5, the evaporator 6, the evaporation pressure regulator 7, and the accumulator 10 in that order. ,
It flows into the compressor 1 again.

Further, since the refrigerant flowing through the outdoor heat exchanger 8 is compressed by the compressor 1 into a high temperature and high pressure gas, the outdoor heat exchanger 8 functions as a condenser for radiating the heat of the refrigerant to the outside. ..

That is, the gas refrigerant which has become high temperature and high pressure in the compressor 1 dissipates heat when passing through the outdoor heat exchanger 8 and becomes a gas-liquid two-phase state. Then, the refrigerant in the gas-liquid two-phase state radiates heat again by passing through the condenser 4 to increase the liquid component, and finally becomes the liquid refrigerant. The refrigerant that has changed from the gas state to the liquid state in the outdoor heat exchanger 8 and the condenser 4 is depressurized by passing through the capillary tube 5. After that, heat is taken from the air in the duct 11 by passing through the evaporator 6, and this air is dehumidified and cooled. The refrigerant, which has returned to the gas state by passing through the evaporator 6, is brought into the high temperature and high pressure state again in the compressor 1.

At this time, if the power of the outdoor heat exchanger fan 9 is increased to increase the heat radiation amount of the refrigerant in the outdoor heat exchanger 8, the heat radiation amount in the condenser 4 is reduced, and the temperature of the air after ventilation of the condenser 4 is decreased. Does not have to be too expensive.

On the other hand, when heating the passenger compartment, the refrigerant flowing out of the compressor 1 in the direction of the arrow in the figure is the outdoor heat exchanger 8
Is bypassed and flows into the condenser 4. Then, the refrigerant flows in the order of the capillary tube 5, the evaporator 6, the evaporation pressure regulator 7, the outdoor heat exchanger 8, and the accumulator 10, and then flows into the compressor 1 again.

Further, since the refrigerant flowing through the outdoor heat exchanger 8 is in a stage before being compressed by the compressor 1, the outdoor heat exchanger 8 functions as an evaporator that removes heat from the outside air. That is, the gas refrigerant that has become high temperature and high pressure in the compressor 1 dissipates heat when passing through the condenser 4 to heat the air in the duct 11, and during that time, the gas refrigerant changes to a liquid refrigerant. The liquefied refrigerant is depressurized by passing through the capillary tube 5, and then passes through the evaporator 6 to evaporate and remove heat from the air in the duct 11,
This air is dehumidified and cooled. The refrigerant further evaporates by passing through the outdoor heat exchanger 8 and also takes heat from the air outside the duct 11. Then, the refrigerant vaporized by passing through the outdoor heat exchanger 8 becomes the gas in the high temperature and high pressure state again by the compressor 1.

At this time, since the refrigerant absorbs heat when passing through both the evaporator 6 and the outdoor heat exchanger 8, the amount of heat released by the condenser 4 also increases. That is, the ability to heat the vehicle interior is increased.

Here, when the engine 15 has just been driven, or after the engine 15 has been stopped for a while, the temperature of the engine cooling water is low, and the temperature of the air after passing through the heater core 14 is low. The temperature will be lower. But first
In the embodiment, since the condenser 4 is arranged on the downstream side of the heater core 14, the cool air after passing through the heater core 14 is heated to a high temperature by the condenser 4, and the warm air is blown into the passenger compartment.

If the engine cooling water temperature is slightly warm, the air after passing through the heater core 14 will also be warm. In consideration of this fact, the cool air dehumidified and cooled by the evaporator 6 is directly heated by the condenser 4,
When the cold air dehumidified and cooled by the evaporator 6 is slightly heated by the heater core 14 and then heated by the condenser 4, the heating load of the condenser 4 is smaller in the latter case.

In consideration of the above, even when the engine cooling water temperature is low, the first air mix damper 16 is opened to allow the heater core 14 to ventilate air, and the slight heat after ventilating the heater core 14 is effectively utilized. The heating load on the condenser 4 can be reduced. This means that the heat radiation amount of the condenser 4 can be reduced, and accordingly, the flow rate of the refrigerant flowing through the condenser 4 can be reduced accordingly. That is, since the compression work of the compressor 1 can be reduced, the power consumed by the compressor 1 can be reduced and the running performance of the vehicle can be improved.

Also, the fact that the heat radiation amount of the condenser 4 can be reduced means that the heat absorption amount of the outdoor heat exchanger 8 can be reduced. That is, the power of the outdoor heat exchanger fan 9 can be reduced to reduce the power consumption of the vehicle as a whole.

When the engine cooling water becomes sufficiently warm, the opening degree of the first air mix damper 16 and the second air mix damper 18 are adjusted appropriately to control the temperature of the air blown into the passenger compartment. Just adjust it. At this time, if the air is sufficiently warmed by the heater core 4, the heating load of the condenser 4 is reduced as described above, and as a result, the power consumption of the compressor 1 and the power consumption of the outdoor heat exchanger fan 9 can be reduced. ..

Further, in the first embodiment, since the evaporator 6 and the condenser 4 are separately provided, the water generated on the surface of the evaporator 6 does not evaporate even when the cooling operation is switched to the heating operation. Absent. As a result, there is no problem that moisture is blown into the passenger compartment to fog the windshield.

Next, a second embodiment will be described with reference to FIG. In this embodiment, a dehumidifying amount variable damper 21 for adjusting the amount of air passing through the evaporator 6 and the amount of air passing through the third bypass passage 20 is provided in the evaporator 6 so that the dehumidifying amount can be varied. This is similar to the first embodiment.

FIG. 3 shows a third embodiment of the heater core 14.
The adjustment of the heat radiation amount in the first embodiment is not performed by switching the first air mix damper 16 as in the first embodiment, but the opening amount of the hot water valve 22 is adjusted to adjust the engine cooling water amount flowing to the heater core 14. It was done by.

FIG. 4 shows a fourth embodiment. In this embodiment, an outdoor evaporator 8a as an outdoor evaporator is arranged between the evaporator 6 and the compressor 1, and between the compressor 1 and the condenser 4. An outdoor condenser 8b as an outdoor condenser is provided. The heat absorption capacity of the outdoor evaporator 8a is adjusted by the outdoor evaporator fan 9a which is a heat absorption amount adjusting means, and the heat dissipation capacity of the outdoor capacitor 8b is an outdoor capacitor fan 9 which is a heat dissipation amount adjusting means.
Adjust with b.

Here, when the outdoor evaporator fan 9a is driven so as to weaken the heat absorption capability of the outdoor evaporator 8a and the outdoor capacitor fan 9b is driven so as to enhance the heat dissipation capability of the outdoor capacitor 8b, the refrigerant is discharged outside the duct 11. It will radiate heat while flowing. That is, the first
This is the same as in the case where the outdoor heat exchanger 8 functions as a condenser in the first to third embodiments. That is, the amount of heat radiation of the condenser 4 provided in the duct 11 is reduced, which is effective when cooling the passenger compartment.

When the outdoor evaporator fan 9a is driven so as to increase the heat absorption capability of the outdoor evaporator 8a and the outdoor condenser fan 9b is driven so as to weaken the heat dissipation capability of the outdoor capacitor 8b, the refrigerant is discharged outside the duct 11. It will absorb heat while flowing. That is, the first
This is the same as the case where the outdoor heat exchanger 8 functions as an evaporator in the first to fourth embodiments. That is, the amount of heat radiation of the condenser 4 provided in the duct 11 increases, which is effective when heating the passenger compartment.

FIG. 5 shows a fifth embodiment, in which the receiver cycle is used instead of the accumulator cycle in the first to third embodiments. Here, 23 is a receiver that temporarily stores the refrigerant so that the refrigerant liquefied by the condenser 4 can be supplied to the evaporator 6 according to the cooling load. 24
Is an expansion valve as an expansion unit that is an expansion unit that rapidly expands the high-temperature and high-pressure liquid refrigerant that has passed through the receiver 23 through a small hole to rapidly expand it into a low-temperature and low-pressure atomized refrigerant. The expansion valve 24 also adjusts the amount of refrigerant to be supplied to the evaporator 6 according to the cooling load detected by the heat-sensitive cylinder 25.

[Brief description of drawings]

FIG. 1 is a block diagram showing an entire vehicle air conditioner according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an entire vehicle air conditioner according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing an entire vehicle air conditioner according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing an entire vehicle air conditioner according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing an entire vehicle air conditioner in a fifth embodiment of the present invention.

[Explanation of symbols]

1 Compressor as a compressor 2 First four-way valve as switching means 3 Second four-way valve as switching means 4 Condenser as condenser 5 Capillary tube as expansion means 6 Evaporator as evaporator 8 Outdoor heat exchanger 8a Outdoor Outdoor evaporator 8b as an evaporator 8b Outdoor condenser as an outdoor condenser 9a Fan for outdoor evaporator 9b as a heat absorption adjusting means 9b Fan for outdoor condenser as a heat dissipation adjusting means 11 Duct 13 Blower 14 Heater core 15 as a heater 15 Engine 24 Expansion valve as expansion means 25 Heat-sensitive cylinder as expansion means

Claims (2)

[Claims] 1. A duct forming an air-conditioning air passage to a vehicle compartment, a blower for blowing air into the vehicle compartment through the duct, a refrigerant disposed in the duct and flowing in the interior of the duct. An evaporator for dehumidifying and cooling the air in the duct by removing heat from the air in the duct; and in the duct by radiating the refrigerant flowing in the duct, which is disposed on the downstream side of the evaporator. A condenser that heats the air, a compressor that is connected between the evaporator and the condenser, and that compresses and discharges the refrigerant, and the refrigerant that is disposed outside the duct and that flows inside itself. And an outdoor heat exchanger for exchanging heat between the duct and air outside the duct, and switching means for switching between the outdoor heat exchanger functioning as an evaporator and the condenser, and the evaporator and the condenser. With Expansion means for decompressing and expanding the refrigerant, and arranged in the duct downstream of the evaporator and upstream of the condenser to heat the air using engine cooling water as a heat source. An air conditioner for a vehicle, comprising: 2. A duct forming an air-conditioning air passage to a vehicle compartment, a blower for blowing air into the vehicle compartment through the duct, a refrigerant disposed in the duct and flowing in the interior of the duct. An evaporator in the duct that dehumidifies and cools the air in the duct by removing heat from the air in the interior, and a refrigerant disposed in the duct downstream of the evaporator to radiate the refrigerant flowing through itself. A condenser in the duct for heating the air in the duct, a compressor connected between the evaporator and the condenser for performing compression discharge of the refrigerant, and arranged outside the duct. An outdoor evaporator that gives heat to the refrigerant by absorbing heat from the air outside the duct by the refrigerant flowing inside itself, and an endothermic amount adjusting means for adjusting the amount of the endothermic heat of the outdoor evaporator; duct An outdoor condenser that is disposed outside and that radiates the refrigerant that flows inside itself, a heat radiation amount adjusting means that adjusts the amount of heat radiation of the outdoor condenser, an evaporator in the duct, and a heat exchanger in the duct. Expansion means connected to the condenser for decompressing and expanding the refrigerant, and arranged in the duct on the downstream side of the evaporator and on the upstream side of the condenser to supply engine cooling water as a heat source. An air conditioner for a vehicle, comprising: a heater that heats the air.