JP3354378B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cooling and heating apparatus using a heat pump system, and more particularly to a cooling and heating apparatus having a simple cycle configuration.

[0002]

2. Description of the Related Art For example, an electric vehicle has an insufficient heating heat source as compared with a vehicle equipped with an engine that uses high-temperature engine cooling water, because a traveling drive source is an electric motor. For this reason, a dehumidifying heat pump air conditioner has been developed in which a conventional electric vehicle cooling / heating device performs a cycle operation using a refrigerant not only for cooling but also for heating, thereby heating the vehicle interior while preventing fogging of windows (for example, JP-A-5-20124
No. 3).

An air conditioner for an electric vehicle of this type is shown in FIG.
As shown in FIG. 1, a blower device 1 for taking in air, a cooler 3, and a vehicle interior heat exchanger 4 mainly functioning during a heating operation are disposed in a duct 2, and further, outside the duct 2,
A vehicle exterior heat exchanger 5 that functions mainly during cooling operation is provided.

The heat exchangers 4 and 5 are switched between a heating operation and a cooling operation by a three-way valve 9 provided during the cycle. In the heating operation, the refrigerant passes through the heat exchanger 5 outside the passenger compartment. The refrigerant flows from the compressor 6 by bypass, and the refrigerant from the compressor 6 flows in the order of the three-way valve 9, the bypass passage 11, the vehicle interior heat exchanger 4, the expansion valve 8, and the cooler 3. In this process, the three-way valve 9 discharged from the compressor 6
The gaseous refrigerant that has bypassed the vehicle interior heat exchanger 5 is condensed and liquefied by the vehicle interior side heat exchanger 4 and radiates heat. Therefore, the air cooled by the cooler 3 is heated and the vehicle interior is heated. Will be.

However, in such a cooling and heating device for an electric vehicle, the cooling air is always cooled by the cooling device 3 because the cooling device 3 and the vehicle interior heat exchanger 4 work simultaneously during the heating operation. After that, the heating is performed by the vehicle interior heat exchanger 4, and thus not only the heating performance is not improved but also there is a problem that unnecessary dehumidification may be performed.

Therefore, for the purpose of improving unnecessary dehumidifying and heating to save power, the outside heat exchanger 5 provided outside the vehicle compartment functions as an evaporator at the time of heating, and a condenser at the time of cooling. An air conditioner system that functions as an air conditioner has also been proposed.

In this air conditioner system, as shown in FIG. 5, during heating, a high-temperature, high-pressure gaseous refrigerant discharged from a compressor 6 is switched to a three-way valve 9 to switch the three-way valve 9 into a vehicle compartment. After being guided to the indoor heat exchanger 4 and condensed and liquefied while heating the intake air, the first expansion valve 8a provided at the inlet of the vehicle exterior heat exchanger 5
As a result, the refrigerant is adiabatically expanded to become a low-temperature and low-pressure liquid refrigerant, and is guided to the vehicle interior heat exchanger 5.

In the outside heat exchanger 5, the low-temperature and low-pressure liquid refrigerant becomes a low-temperature and low-pressure gaseous refrigerant while cooling the outside air, and is returned to the compressor 6 through the bypass pipe 11. That is, at the time of heating, the heat exchanger 5 outside the vehicle compartment functions as an evaporator, and the refrigerant is not guided to the cooler 3 inside the vehicle compartment, so that unnecessary dehumidifying heating is improved.

In the mode in which the fogging of the windowpane is cleared, a part of the refrigerant from the vehicle exterior heat exchanger 5 is guided to the cooler 3 in the above cycle.

On the other hand, during cooling, the compressor 6
The high-temperature and high-pressure gaseous refrigerant discharged from the cooling device 3 is guided to the vehicle interior heat exchanger 5 by switching the three-way valve 9 and is condensed and liquefied while heating the outside air. The refrigerant is adiabatically expanded by the second expansion valve 8b and becomes a low-temperature and low-pressure liquid refrigerant, which is guided to the cooler 3.

The low-temperature, low-pressure liquid refrigerant becomes a low-temperature, low-pressure gaseous refrigerant while cooling the intake air in the cooler 3, and is returned to the compressor 6.

[0012]

However, in such an air conditioner system, the three-way valve 9 provided at the outlet of the compressor 6, the bypass pipe 11, and the bypass pipe 11 are provided.
Since the solenoid valve provided in is required, the cycle configuration becomes complicated and the product cost increases,
With the increase in the number of components, there is a possibility that reliability such as refrigerant leakage or malfunction may be reduced.

The present invention has been made in view of the above-described problems, and has as its object to provide a cooling and heating apparatus having a simple configuration.

[0014]

According to a first aspect of the present invention, there is provided a cooling and heating apparatus comprising: a compressor; an indoor heat exchanger; a first expansion valve;
An outdoor heat exchanger, a second expansion valve, and a cooler are a cooling and heating device in which the cooling device is connected in this order by pipes. During the heating operation, the refrigerant is adiabatically expanded by the first expansion valve and the pipes are connected in the above order.
In the cooling operation, the refrigerant is circulated in the above order without adiabatic expansion of the refrigerant by the first expansion valve.

In this cooling / heating device, a first expansion valve is provided upstream of the outdoor heat exchanger. In this expansion valve, the refrigerant expands adiabatically during the heating operation, and does not expand adiabatically during the cooling operation. The cycle operation during the heating operation and the cooling operation is as follows.

That is, during the heating operation, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor is guided to the indoor heat exchanger and is condensed and liquefied while heating the intake air. It is adiabatically expanded and becomes a low-temperature and low-pressure liquid refrigerant, which is guided to the outdoor heat exchanger.

The low-temperature and low-pressure liquid refrigerant is turned into a low-temperature and low-pressure gaseous refrigerant while cooling the outside air in the outdoor heat exchanger, and is further cooled by the second expansion valve and the cooler. , Returned to the compressor.

That is, the outdoor heat exchanger according to the present invention functions as an evaporator during heating.
Further, the refrigerant passing through the second expansion valve is already a low-temperature and low-pressure liquid refrigerant and only slightly cools the intake air, so that unnecessary dehumidifying heating is improved. At the same time, it is not a thing that does not perform dehumidification at all, so that it is possible to clear the fogging of the window glass.

On the other hand, during the cooling operation, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor is guided to the indoor heat exchanger to exchange heat with the intake air, and then leaves the first expansion valve as it is. It passes through and is guided to the outdoor heat exchanger. In the indoor heat exchanger and the outdoor heat exchanger, the high-temperature and high-pressure gaseous refrigerant is condensed and liquefied while exchanging heat with the outside air, and then adiabatically expanded by the second expansion valve provided at the inlet of the cooler. Then, it becomes a low-temperature and low-pressure liquid refrigerant and is led to a cooler.

The low-temperature and low-pressure liquid refrigerant becomes a low-temperature and low-pressure gaseous refrigerant while cooling the intake air in the cooler, and is returned to the compressor.

That is, the outdoor heat exchanger according to the present invention functions as a condenser during cooling.

As described above, since the cooling and heating apparatus of the present invention can perform cooling and heating in one cycle, the switching valve and the bypass pipe conventionally required can be omitted. Cycle, not only reducing product costs and exclusive space,
Problems such as leakage of the refrigerant and malfunctions can also be solved.

According to the second aspect of the present invention, the presence or absence of adiabatic expansion of the refrigerant in the first expansion valve during the heating operation and the cooling operation is controlled by adjusting the valve opening of the first expansion valve. It is characterized by that.

In controlling the adiabatic expansion of the refrigerant in the first expansion valve in accordance with the cooling and heating, the control can be easily performed by adjusting the valve opening of the first expansion valve. At the time of heating, since adiabatic expansion is necessary, the valve opening of the first expansion valve is set to a small control mode, and at the time of cooling, the valve opening of the first expansion valve is fully opened to prevent adiabatic expansion.

According to a third aspect of the present invention, the presence or absence of the adiabatic expansion of the refrigerant in the first expansion valve during the heating operation and the cooling operation adjusts the amount of the refrigerant flowing through the bypass pipe bypassing the first expansion valve. And is controlled by

In addition to the control based on the opening degree of the first expansion valve, a bypass pipe bypassing the first expansion valve is provided in a pipe constituting a cycle to adjust the opening degree of the first expansion valve. It can also be controlled by adjusting the amount of refrigerant flowing through the bypass pipe without the need. That is, adiabatic expansion is required during heating, so that all refrigerant flows through the first expansion valve, and during cooling, all refrigerant flows through the bypass pipe in order to prevent adiabatic expansion.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 are schematic configuration diagrams showing an embodiment of a cooling and heating device for an electric vehicle according to the present invention. Note that, in the figure, the same reference numerals are given to parts common to FIGS. 4 and 5.

The cooling and heating device for an electric vehicle according to the present embodiment is a heat pump type air conditioner for performing cooling and dehumidifying heating in a vehicle compartment by performing a cycle operation using a refrigerant for both cooling and heating.

The cycle C of the air conditioner includes a compressor 6, a heat exchanger 4 inside the vehicle, a liquid tank 7a,
Expansion valve 8a, exterior heat exchanger 5, liquid tank 7
b, the second expansion valve 8b and the cooler 3 are connected by piping,
It is configured such that a refrigerant is sealed therein.

Although not shown, a fan device for sending air to the outside heat exchanger 5 is provided on the rear side of the outside heat exchanger 5.

In such a cycle C, the refrigerant discharged from the compressor 6 is supplied to the vehicle interior heat exchanger 4 → the liquid tank in both the heating operation and the cooling operation, as shown in FIGS. The same circulation path that circulates from 7a → first expansion valve 8a → vehicle exterior heat exchanger 5 → liquid tank 7b → second expansion valve 8b → cooler 3 → compressor 6 is formed.

In some cases, all or part of the liquid tanks 7a and 7b may be omitted to simplify the configuration. The compressor 6 is driven directly by an electric motor or via a belt (not shown). That is, the driving of the electric vehicle and the driving of the compressor 6 are performed by the battery.

The cooling and heating device for an electric vehicle according to the present embodiment has a duct 2 constituting an air passage for intake air, and comprises a blower fan and a blower fan motor for driving the blower fan on the upstream side. A blower device 1 is provided, whereby the intake air is sent into the vehicle interior.

The cooler 3 and the vehicle interior heat exchanger 4 are arranged in this order in the duct 2 from the upstream side, and the air mixing door 13 is rotated upstream of the vehicle interior side heat exchanger 4. It is provided freely, and the ratio of the air volume passing through the vehicle interior heat exchanger 4 to the air volume bypassing the vehicle interior heat exchanger 13 is adjusted.

Further, a mixing chamber 1 is provided downstream of the duct 2.
8 is formed, and in this mixing chamber 18, the hot air that has passed through the vehicle interior heat exchanger 4 and the cool air that has bypassed the vehicle interior heat exchanger 4 are mixed, so that an airflow having a desired temperature is obtained. Temperature controlled.

The temperature-controlled air is blown out from various outlets (not shown), for example, vent outlets, foot outlets, differential outlets, etc., toward a predetermined location in the vehicle compartment.

In this embodiment, the operation of the first expansion valve 8a is different between the heating operation and the cooling operation. That is, like the second expansion valve 8b provided at the inlet of the cooler 3, the first expansion valve 8a is an electromagnetic expansion valve whose valve opening is controlled according to the temperature of the refrigerant on the outlet side of the heat exchanger. During heating, a temperature-sensitive cylinder (not shown) provided on the outlet side pipe of the heat exchanger 5 on the outside of the passenger compartment causes a temperature-sensitive cylinder (not shown) to operate as shown in FIG.
As shown in (1), the valve opening of the first expansion valve 8a is controlled, and the vehicle interior heat exchanger 5 functions as an evaporator. However, at the time of cooling, the first expansion valve 8a is forced to fully open as shown in FIG. 2B in order to make the vehicle interior heat exchanger 5 function as a condenser.

Such control of the valve opening can be easily performed by the output voltage to the electromagnetic expansion valve 8a, but can also be performed by the bypass pipe 15a bypassing the first expansion valve 8a. it can. FIG. 3 is a schematic diagram showing another embodiment of the present invention.
A bypass pipe 15a is provided so as to bypass the expansion valve 8a, and an electromagnetic valve 15b is provided in the bypass pipe 15a.

During heating, the solenoid valve 15b is fully closed so that the first expansion valve 8a performs normal control, and all the refrigerant flows through the first expansion valve 8a. On the other hand, at the time of cooling, the solenoid valve 15b is fully opened to allow most of the refrigerant to flow through the bypass pipe 15a, thereby suppressing adiabatic expansion of the refrigerant in the first expansion valve 8a.

Next, the operation of the embodiment will be described. For example, when the air conditioner switch is turned on, the system is started, the compressor 6 is turned on, and the opening degree of the first expansion valve 8a is switched according to the required air condition in the vehicle compartment. As described above, the function of the vehicle exterior heat exchanger 5 is switched between the heating operation and the cooling operation according to the valve opening degree.

First, when performing the heating operation including the temperature control, the opening degree of the first expansion valve 8a is set to the normal control mode. As a result, the vehicle interior heat exchanger 5 functions as an evaporator, and the refrigerant in the cycle C is supplied from the compressor 6 → the vehicle interior side heat exchanger 4 → the liquid tank 7a →
First expansion valve 8a → heat exchanger 5 outside vehicle compartment → liquid tank 7b → second expansion valve 8b → cooler 3 → compressor 6
Circuit.

In this process, heat is exchanged with the intake air in the vehicle interior heat exchanger 4 to heat it. At this time, the heat is released by the external heat exchanger 5 by the external heat exchanger 5. Endothermic. Further, heat exchange is also performed in the cooler 3 to slightly cool the intake air. Therefore,
Heating with some but not excessive dehumidification is realized, and will serve to clear the fogging of the window glass.

The temperature control is performed by adjusting the opening of an air mix door 13 provided upstream of the vehicle interior heat exchanger 4.

When the outside heat exchanger 5 freezes during heating, the first expansion valve 8a can be thawed in a short time by fully opening the first expansion valve 8a temporarily. Further, even if the heat exchanger 5 outside the vehicle compartment freezes, the heat exchanger 4 inside the vehicle compartment can exhibit heating performance without freezing.

When performing the cooling operation, the first expansion valve 8
a and the air mix door 1
3 is in a fully closed state or a state close thereto.

As a result, the heat exchanger 5 outside the vehicle compartment functions as a condenser, and the refrigerant in the cycle C is supplied from the compressor 6 → the heat exchanger 4 inside the vehicle → the liquid tank 7a → the first tank.
Expansion valve 8a → exterior heat exchanger 5 → liquid tank 7
b → the second expansion valve 8b → the cooler 3 → the compressor 6;

In this process, since the second expansion valve 8b operates in the normal control mode, the cooler 3
The heat is exchanged with the intake air to cool it, and the heat absorbed at this time is mainly released to the outside air in the vehicle exterior heat exchanger 5. In other words, since the opening degree of the first expansion valve 8a is fully open, the vehicle interior heat exchanger 5 functions as a condenser, and condenses and liquefies the gaseous refrigerant that has become high temperature and high pressure by the compressor 6. . However, when the air mix door 13 is opened, heat is also exchanged by the vehicle interior heat exchanger 4 and the intake air cooled by the cooler 3 can be heated, and as a result, the temperature is controlled and dehumidified. The Rukoto.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the claims. For example, in the above-described embodiment, the cooling and heating device for an electric vehicle has been described. However, the present invention is not limited to this, and can be applied to a normal cooling and heating device used in a general home. Needless to say.

[0049]

As described above, according to the air conditioner of the first aspect of the present invention, since the directional control valve and the bypass refrigerant pipe are not provided, the circuit configuration is simplified, and the product cost and space are reduced. In addition to the reduction, it is possible to eliminate problems such as refrigerant leakage from component parts and malfunction.

Further, according to the cooling and heating apparatus of the second aspect, the presence or absence of adiabatic expansion can be easily controlled by electric control, so that cost increase can be suppressed to a minimum.

According to the third aspect of the invention, the provision of the bypass pipe makes it possible to reliably control the presence or absence of adiabatic expansion regardless of clogging of the first expansion valve.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram (at the time of a heating operation) showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram (at the time of cooling operation) showing an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing another embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a conventional air conditioner for an electric vehicle.

FIG. 5 is a schematic configuration diagram showing a conventional cooling and heating device for an electric vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Blower apparatus, 2 ... Duct, 3 ... Cooler, 4 ... (Car) indoor heat exchanger, 5 ... (Car) outdoor heat exchanger, 6 ... Compressor, 8 ... Expansion valve, 8a ... First Expansion valve, 8b: second expansion valve, 15a: bypass pipe, 15b: solenoid valve.

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/32 B60H 1/22

Claims (3)

(57) [Claims] 1. A compressor (6), an indoor heat exchanger (4),
First expansion valve (8a), outdoor heat exchanger (5), second expansion valve
(8a) and a cooler (3) connected in this order by piping, and the refrigerant is adiabatically expanded by the first expansion valve (8a) during the heating operation.
In the cooling operation, the refrigerant is circulated in the above order without adiabatically expanding the refrigerant by the first expansion valve (8a).
Cooling and heating system characterized by circulating pipes 2. The presence or absence of adiabatic expansion of the refrigerant in the first expansion valve (8a) during the heating operation and the cooling operation is controlled by adjusting the valve opening of the first expansion valve (8a). The cooling and heating device according to claim 1, wherein: The presence or absence of adiabatic expansion of the refrigerant in the first expansion valve (8a) during the heating operation and the cooling operation depends on whether the refrigerant flowing through the bypass pipe (15a) bypassing the first expansion valve (8a). The cooling and heating device according to claim 1, wherein the heating and cooling device is controlled by adjusting the amount.