JPH11301254A - Air conditioner for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a safety that a possibility of an explosion in a car interior is low even if a refrigerant leaks out by a collision accident etc., by using hydrocarbon as the refrigerant, disposing a refrigerating cycle having an evaporator and a condenser on the lower side outside the car and circulating a brine between the evaporator and a heat exchanger in the car interior. SOLUTION: A heat exchanger 2 having a condenser function and a heat exchanger 5 having an evaporator function carry out a heat exchange of a refrigerant using a hydrocarbon and a brine (water), and the brine is circulated between a heat exchanger 10 outside the car and a heat exchanger 11 for cooling the car interior. Further, all of a compressor 1 through which an inflammable hydrocarbon passes, the heat exchanger 2 having the condenser function, the heat exchanger 5 having the evaporator function and a refrigerant piping 20 are separated from the car interior and disposed at a position that a lower portion outside the car is not covered and a vent hole to a road surface exists. On the other hand, the heat exchanger for cooling the car interior is disposed in the car interior and the car interior is cooled by circulating the brine. Thereby, a danger of causing explosion is small even if the refrigerant leaks out by collision, etc.

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 using a refrigeration cycle.

[0002]

2. Description of the Related Art In a conventional automotive air conditioner, a CFC-based refrigerant has been used for a long time. However, because of global environmental problems, we will stop using it,
A refrigeration cycle using carbon dioxide as a refrigerant instead of a chlorofluorocarbon-based refrigerant has been studied.

[0003]

Although carbon dioxide is excellent in that it is nonflammable, since the saturated vapor pressure is more than ten times higher than that of a conventional refrigerant, the pressure resistance of the system constituting the refrigeration cycle is reduced. There is a major disadvantage that it must be very large.

[0004] Therefore, it is conceivable to use a hydrocarbon as a refrigerant. Hydrocarbons have characteristics similar to those of CFC-based refrigerants, can easily obtain the conventional level of refrigeration performance, and have the advantage of a low global warming potential.

However, since hydrocarbons are flammable, there is a risk of explosion due to ignition of the refrigerant leaked from the broken pipe when a vehicle collides. In particular, it is extremely dangerous if refrigerant leaks into the vehicle compartment and explodes.

Therefore, the present invention uses a refrigeration cycle using a hydrocarbon as a refrigerant, and has a low possibility of explosion even if the refrigerant leaks in the event of an automobile collision or the like. It is an object of the present invention to provide an automotive air conditioner with high performance.

[0007]

In order to achieve the above object, an automotive air conditioner according to the present invention uses a hydrocarbon as a circulating refrigerant and functions as a heat exchanger functioning as an evaporator and a condenser. A refrigeration cycle provided with a heat exchanger to be disposed was disposed at a position having a vent below the outside of the vehicle compartment, and brine was circulated between the heat exchanger functioning as the evaporator and the vehicle interior heat exchanger. It is characterized by the following.

An outside air heat exchanger for exchanging heat with the outside air is provided, and a brine is also provided between the outside air heat exchanger and the heat exchanger functioning as the condenser. May be circulated.

Then, the flow directions of the refrigerant with respect to the heat exchanger functioning as the evaporator and the heat exchanger functioning as the condenser are reversed to function as the heat exchanger functioning as the evaporator and the condenser. A refrigerant circuit switching valve that allows the function of the heat exchanger to be freely switched may be provided.

[0010] Further, a heat exchanger in a refrigeration cycle, which is a counterpart of a brine circulated through the vehicle interior heat exchanger and the outside air heat exchanger, is used as the evaporator and the heat exchanger. A brine circulation path switching valve that can be switched to a heat exchanger functioning as a heat exchanger may be provided.

Further, a second vehicle interior heat exchanger is provided in which brine is circulated between the heat exchanger functioning as the condenser and the second vehicle interior heat exchanger and the first vehicle. A valve for opening and closing a brine circulation path for each of the indoor heat exchanger and the outdoor air heat exchanger may be provided.

In this case, a door may be provided for regulating the heat exchange between the second vehicle interior heat exchanger and the air in the vehicle interior to an arbitrary level. The heat exchanger may be provided with a pipe for circulating cooling water for the engine of the vehicle.

[0013]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an air conditioner for a vehicle according to a first embodiment of the present invention. The air conditioner for a vehicle according to the first embodiment of the present invention performs only cooling in a vehicle compartment by the most basic configuration.

The refrigerant line 20 includes a compressor 1 for compressing the refrigerant, a heat exchanger 2 functioning as a condenser for condensing the compressed refrigerant, a liquid tank 3 for temporarily storing the refrigerant liquid, An annular pipe is provided so as to return to the compressor 1 through an expansion valve 4 for adiabatically expanding the refrigerant and a heat exchanger 5 functioning as an evaporator for evaporating the refrigerant. Hydrogen circulates through it.

The heat exchanger 2 functioning as a condenser is configured to perform heat exchange between the refrigerant and the brine, and the outside brine is circulated between the outside heat exchanger 10 and the brine. A pipe 21 is provided in a ring shape. For example, water is used as the brine. Reference numeral 6 denotes a pump for circulating brine, and reference numeral 7 denotes a fan for promoting heat exchange between the brine and the outside air in the heat exchanger 10 outside the vehicle compartment.

The heat exchanger 5 functioning as an evaporator is also configured to perform heat exchange between the refrigerant and the brine, so that the brine circulates between the heat exchanger 11 for cooling the vehicle interior. A vehicle interior brine pipeline 22 is arranged in a ring shape. For example, water is used as the brine. 8
Is a pump for circulating brine, and 9 is a fan for promoting heat exchange between the brine and the air in the vehicle cabin in the heat exchanger 11 for cooling the vehicle cabin.

FIG. 2 schematically shows the arrangement of the air conditioner for a vehicle configured as described above. The compressor 1 through which combustible hydrocarbons pass, the heat exchanger 2 functioning as a condenser, the liquid tank 3, the expansion valve 4, the heat exchanger 5 functioning as an evaporator, and the refrigerant pipe 20 are all from the vehicle interior 101. It is arranged in the isolated engine room 102, for example, on the side of the engine 103, and is designed so that a direct impact on the vehicles is unlikely to be applied when the vehicles collide.

The members 1, 2, 3, 4, 5, and 2 for circulating hydrocarbons so that even if hydrocarbons leak due to collision or the like, they do not fill the engine room 102.
No. 0 is located at a position where there is no large cover and there is a large ventilation hole leading to the road surface.

On the other hand, the vehicle exterior heat exchanger 10 is arranged, for example, in front of the engine room 102, which is exposed to the outside air during traveling, and is provided between the brine passing through the vehicle exterior heat exchanger 10 and the atmosphere. Sufficient heat exchange is performed.

On the other hand, the heat exchanger 11 for cooling the passenger compartment is
1, heat exchange is performed between the brine passing through the heat exchanger 11 for cooling the vehicle interior and the air in the vehicle interior 101, and cooling in the vehicle interior 101 is performed. .

By adopting such an arrangement, the interior of the passenger compartment 101 can be cooled with high efficiency, and there is a danger of explosion even if hydrocarbons used as a refrigerant leak due to collision or the like. small. In addition, adopting such an arrangement is the same in each of the following embodiments.

FIG. 3 shows an air conditioner for a vehicle according to a second embodiment of the present invention, in which an accumulator 3 ′ is connected to the inlet side of the compressor 1 instead of the liquid tank 3.
Refrigerant line 2 to which compressor 1 and accumulator 3 'are connected
A four-way valve 31 is inserted and connected between both ends of the pipe 0 'and the refrigerant pipe 20 to which the heat exchangers 2 and 5 are connected. Other configurations are the same as those of the first embodiment.

With this configuration, as shown by the solid arrow and the broken arrow in FIG. 3, the heat exchanger 2 functioning as a condenser and the heat exchanger 5 functioning as an evaporator.
Can be switched so that the refrigerant (hydrocarbon) flows in the opposite direction to the refrigerant pipe line 20 to which is connected.

As a result, the function of the heat exchanger 2 functioning as a condenser and the function of the heat exchanger 5 functioning as an evaporator are interchanged, so that the interior of the vehicle interior 101 can be switched between cooling and heat pump heating. it can.

FIG. 4 shows an air conditioner for a vehicle according to a third embodiment of the present invention. Refrigeration cycles 1, 2, 3, 4, and 5 in which a hydrocarbon refrigerant circulates are shown in FIG. Exactly the same as the form, in addition to the outside brine line 2
1 and a pair of four-way valves 41 and 42 for switching the flow path of the brine with respect to the vehicle interior brine pipeline 22.

With this configuration, the brine warmed by the heat exchanger 2 functioning as a condenser flows through the heat exchanger 10 outside the vehicle and is evaporated, as indicated by solid arrows in FIG. The brine cooled by the heat exchanger 5 functioning as a heat exchanger is cooled by the heat exchanger 5 functioning as an evaporator, as indicated by a dashed arrow, and a cooling state flowing through the heat exchanger 11 for cooling the passenger compartment. The heated brine is flown to the heat exchanger 10 outside the vehicle compartment, and the brine heated by the heat exchanger 2 functioning as a condenser can be switched to a heating state to be flown to the heat exchanger 11 for cooling the vehicle interior.

In each of the embodiments shown in FIG. 5 and subsequent figures, a dehumidification (dry) function is added in addition to the cooling and heating in the passenger compartment 101, so that various air conditioning modes can be selected. I have.

If these are described in writing one by one, it is complicated and difficult to understand. Therefore, the relationship between the air-conditioning mode and the opening / closing of the valves will be described in a table. In each table, 表 means open, ● means closed, and −- ○ means communication. The air conditioning mode is as follows.

[Cooling] The heat exchanger 11 for cooling the vehicle compartment works for cooling. Hot water (brine) may flow through the heat exchanger 12 for heating the vehicle interior (it does not function as heating if the air mix door 13 is closed, or a detour may be provided as in the embodiment shown in FIG. 8). ).

[Dry C] The heat exchanger 11 for cooling the vehicle interior works for cooling. Hot water (brine) is flowing into the heat exchanger 12 for heating the vehicle interior (the cooling water (brine) of the heat exchanger 2 functioning as a condenser is flowing through the heat exchanger 10 outside the vehicle, and the heating capacity is higher. But small dry operation).

[Dry H] The heat exchanger 11 for cooling the vehicle interior works for cooling, and hot water (brine) flows through the heat exchanger 12 for heating the vehicle interior (the heat exchanger 10 outside the vehicle is used as an evaporator). Water (brine) that warms the functioning heat exchanger 5
Dry operation with larger heating capacity).

[Heating O] The vehicle interior heating heat exchanger 12 works for heating. Including the case where the heat exchanger 11 for cooling the vehicle interior works as a cooling device and hot water (brine) flows through the heat exchanger 12 for heating the vehicle interior, the cooling water ( It is better that brine is not flowing. Operation that can recover heat from outside air.

[Heating E] Heating when the brine for heating the heat exchanger 5 functioning as an evaporator is connected to the engine cooling water, and the heat of the engine 103 can be recovered.

[Heating OE] This is an operation in which the heating O and the heating E are combined, and heat recovery of the outside air is performed by the heat exchanger 10 outside the vehicle compartment.
In addition, heat recovery of the engine 103 can be performed. [Heating L] An operation in which no brine is supplied to the heat exchanger 10 outside the vehicle compartment. When the temperature of the engine cooling water is not available because the outside air is not useful for heat recovery. Only the energy given to the compressor 1 becomes the heating capacity.

[Heating S] When the temperature of the engine cooling water can be used for heating without any change. The refrigeration cycle is not operated, and the operation is such that the engine cooling water flows directly to the heat exchanger 12 for heating the vehicle interior (the same operation as the conventional one using the engine cooling water for heating).

FIG. 5 shows an air conditioner for a vehicle according to a fourth embodiment of the present invention. The air conditioner is provided with a heat exchanger 5 functioning as an evaporator so that a dry mode can be set. In addition to the heat exchanger 11 for cooling the vehicle interior, in which the air is circulated, the brine is circulated between the heat exchanger 2 which is connected in series to the heat exchanger 10 outside the vehicle and functions as a condenser. The heat exchanger 12 is arranged in the passenger compartment 101.

The heat exchanger 12 for heating the vehicle interior includes the vehicle interior 10
An air mix door 13 for restricting heat exchange with air in the inside 1 to an arbitrary level is additionally provided, and the air in the passenger compartment 101 supplied by a fan (not shown)
First, after passing through the heat exchanger 11 for cooling the vehicle interior, the air mixing door 13 separates into a passage passing through the heat exchanger 12 for heating the vehicle interior and a passage bypassing the heat exchanger 12 for heating the vehicle interior.

Therefore, by controlling the opening degree of the air mix door 13, the heat exchange between the heat exchanger 12 for heating the passenger compartment and the air in the passenger compartment 101 is regulated to an arbitrary level, and the heating capacity is varied. (The same applies to the following embodiments).

The exterior heat exchanger 10 is connected to both an exterior brine pipeline 21 and an interior brine pipeline 22 by piping, and has six open / close valves VI to VI for communicating or closing them. V6 is mounted as shown in FIG. It should be noted that the six on-off valves VI to V6 may be configured as a single block.

As a result, in the automotive air conditioner of this embodiment, as shown in the following Table 1, the three on-off valves V1, V5, and V6 are closed and the remaining three on-off valves V
2, V3 and V4 are opened to perform cooling in the vehicle interior cooling heat exchanger 11.

At this time, since warm brine flows through the heat exchanger 10 outside the vehicle compartment and the heat exchanger 12 for heating the vehicle interior, if the air mix door 13 is closed, the cooling mode is set.
When the air mix door 13 is opened, a dry C mode in which dehumidification by weak cooling is performed is performed.

Conversely, if the three on-off valves V1, V5, and V6 are opened and the remaining three on-off valves V2, V3, and V4 are closed, cooling is performed by the vehicle interior cooling heat exchanger 11. Since the indoor cooling heat exchanger 11 is connected in series with the vehicle exterior heat exchanger 10, the cooling capacity is small, and the heating capacity performed by the vehicle interior heating heat exchanger 12 is larger.

Therefore, if the air mix door 13 is opened, the heating O mode is set, and if the air mix door 13 is closed to some extent, the dry H mode in which dehumidification by weak heating is performed is performed.

When the four on-off valves V2, V3, V5 and V6 are closed using the two on-off valves V1 and V4, no brine flows into the heat exchanger 10 outside the vehicle, and the heating L mode is set. Become.

[0045]

[Table 1] FIG. 6 shows an automotive air conditioner according to a fifth embodiment of the present invention. In order to increase the heating capacity, a bypass pipe for preventing the brine from passing through the heat exchanger 11 for cooling the vehicle interior,
On-off valves V7 and V8 for opening and closing the pipeline are provided. The other parts are the same as in the fourth embodiment in FIG.

In this manner, as shown in the following Table 2, by closing the V7 on-off valve and opening the V8 on-off valve in the heating O mode, the cooling in the vehicle interior cooling heat exchanger 11 is performed. The operation stops and the heating capacity increases.

[0047]

[Table 2] FIG. 7 shows a vehicle air conditioner according to a sixth embodiment of the present invention.
The cooling water of No. 3 can be recovered for heating.

In order to obtain the heating effect by flowing the engine cooling water directly to the heat exchanger 12 for the heating, the temperature of the engine cooling water needs to be 60 ° C. In this case, the temperature is lower. But it can contribute to the heating effect.

In the figure, reference numeral 103 denotes an automobile engine;
Is a radiator between which engine cooling water is circulated by the pump 105. 106 and 107 are a check valve and a thermo valve inserted and connected in the middle of the pipe through which the engine cooling water passes.

The brine piping according to this embodiment includes opening / closing valves V11 and V14 for short-circuiting the vehicle exterior brine pipeline 21 and the vehicle interior brine pipeline 22, respectively, and the vehicle exterior heat exchanger 10 as well. Three-way switching valves V12 and V13 are provided for selectively connecting to either the outdoor brine pipeline 21 or the vehicle interior brine pipeline 22 (complete closure is also possible).

V15, V16 and V17 denote on-off valves for opening and closing between the engine cooling water pipe and the vehicle interior brine pipe 22, and V18 and V19 denote the same vehicle as in the fifth embodiment. This is an on-off valve for opening and closing a bypass pipe for preventing brine from passing through the indoor cooling heat exchanger 11.

In the air conditioner for a vehicle according to the embodiment configured as described above, as shown in the following Table 3, in addition to the functions of the fifth embodiment, V15 is closed and V16 is closed.
And V17 are opened, and V12 and V13 are switched between the completely closed state and the circulation from the vehicle interior brine line 22 to the external heat exchanger 10, thereby recovering the heat of the engine cooling water for the heating effect. E and heating OE modes can be added.

[0053]

[Table 3] FIG. 8 shows a vehicle air conditioner according to a seventh embodiment of the present invention.
The heat of the cooling water of No. 3 is recovered for heating.

The vehicle air conditioner of this embodiment has a sixth point in that the piping for the engine cooling water and the external heat exchanger 10 are connected in parallel, and the on-off valves V21 to V30 are arranged in accordance with the piping. The embodiment is different from that of the first embodiment in that the on-off valve V21 is adjusted according to the difference in the valve arrangement as shown in the following Table 4.
By combining the open / close states of V30, a similar air-conditioning mode as in the sixth embodiment can be obtained.

[0055]

[Table 4] FIG. 9 shows an air conditioner for a vehicle according to an eighth embodiment of the present invention, in which heat of engine cooling water is recovered for heating as in the sixth and seventh embodiments. However, when the temperature of the engine cooling water is high and sufficient heating capacity can be obtained without operating the refrigeration cycle, the operation of the refrigeration cycle is stopped, and the engine cooling water is supplied to the vehicle interior heating heat. The heating S mode that can flow directly to the exchanger 12 is obtained.

Therefore, in this embodiment,
In addition to the structure of the seventh embodiment shown in FIG. 8, on-off valves V32 and V33 are connected in parallel with the heat exchanger 2 functioning as a condenser and the heat exchanger 5 functioning as an evaporator. In the heating S mode, as shown in the following Table 5, the on-off valve V32 serving as a bypass of the heat exchanger 2 functioning as a condenser and the heat exchanger 5 functioning as an evaporator,
V33 is opened.

It should be noted that there may be no detour provided with the on-off valve V29 for bypassing the heat exchanger 11 for cooling the vehicle interior, but when the pipe resistance of the heat exchanger 11 for cooling the vehicle interior is large, Opens V29 and opens the heat exchanger 1
It is preferable to bypass 1.

[0058]

[Table 5]

[0059]

According to the present invention, by using hydrocarbons as the refrigerant circulating in the refrigeration cycle, it is possible to obtain a refrigeration effect of excellent efficiency with a device having the same pressure resistance as when using a chlorofluorocarbon-based refrigerant. By arranging the refrigeration cycle at a position with a vent below the outside of the cabin, the possibility of explosion is low even if the refrigerant leaks in the event of an automobile collision, etc. Since the brine is circulated between the heat exchanger functioning as a heat exchanger and the cabin heat exchanger, there is no possibility of explosion of the cabin.

Then, the pipeline can be switched so that the flow of the refrigerant to the two heat exchangers in the refrigeration cycle is reversed, or the heat exchanger in the refrigeration cycle with which the brine circulates can be switched. By doing so, it is possible to heat the vehicle interior, and by providing a vehicle interior heating heat exchanger for heating, it is possible to obtain various wide air conditioning modes including a dehumidifying effect.

[Brief description of the drawings]

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

FIG. 2 is a schematic plan view showing an arrangement of the automotive air conditioner in the automobile according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an automotive air conditioner according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of an automotive air conditioner according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of an automotive air conditioner according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of a vehicle air conditioner according to a fifth embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration of an automotive air conditioner according to a sixth embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of an automotive air conditioner according to a seventh embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of an automotive air conditioner according to an eighth embodiment of the present invention.

[Explanation of symbols]

 2 Heat exchanger functioning as a condenser 5 Heat exchanger functioning as an evaporator 10 Outside heat exchanger 11 Heat exchanger for vehicle interior cooling 12 Heat exchanger for vehicle interior heating 13 Air mix door 104 Radiator

Claims (7)

[Claims] 1. A refrigeration cycle in which a hydrocarbon is used as a circulating refrigerant and a heat exchanger functioning as an evaporator and a heat exchanger functioning as a condenser are provided with a vent hole below the outside of the vehicle compartment. A vehicle air conditioner, wherein brine is circulated between a heat exchanger functioning as the evaporator and a vehicle interior heat exchanger, the brine being disposed at a position. 2. An outside air heat exchanger for performing heat exchange with the outside air is provided, and a brine is also provided between the outside air heat exchanger and the heat exchanger functioning as the condenser. The vehicle air conditioner according to claim 1, wherein the air is circulated. 3. The heat exchanger functioning as the evaporator and the condenser function by reversing the flow direction of the refrigerant to the heat exchanger functioning as the evaporator and the heat exchanger functioning as the condenser. The vehicle air conditioner according to claim 1 or 2, further comprising a refrigerant circulation path switching valve that switches a function of the heat exchanger. 4. A heat exchanger in a refrigeration cycle to be circulated by the brine flowing through the vehicle interior heat exchanger and the outside air heat exchanger, and a heat exchanger functioning as the evaporator, and the condenser. 3. The automotive air conditioner according to claim 2, further comprising a brine circulation path switching valve that is capable of switching to a heat exchanger functioning as a heat exchanger. 5. A second vehicle interior heat exchanger in which brine is circulated between the heat exchanger functioning as the condenser and a second vehicle interior heat exchanger is provided. The automotive air conditioner according to claim 2, further comprising a valve for opening and closing a brine circulation path for each of the heat exchanger and the outside air heat exchanger. 6. An air conditioner for an automobile according to claim 5, further comprising a door for restricting heat exchange between the second heat exchanger inside the vehicle and air inside the vehicle to an arbitrary level. 7. The vehicle air conditioner according to claim 5, wherein a pipe for circulating engine cooling water is provided in the second vehicle interior heat exchanger.