JPH06347111A - Cooling and heating cycle of air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To provide a cooling and heating cycle of an air conditioner in which a heating capability under a heating operation is improved. CONSTITUTION:A compressor 13 and an expansion valve 11 are connected through a third heat exchanger 15 installed outside an air conditioning duct and a second heat exchanger 8 installed within the air conditioning duct. There is provided a passage for use in connecting the expansion valve 11 with the compressor 13 through a first heat exchanger 7 installed within the air conditioning duct. The compressor 13 and the expansion valve 11 are connected through the second heat exchanger 8 in respect to this passage. There is also provided a passage for use in connecting the expansion valve 11 with the compressor 13 through the third heat exchanger 15. During a heating operation, refrigerant discharged from the compressor 13 is sent to the expansion valve 11. through the second heat exchanger 8 and thereafter the refrigerant is returned back to the compressor 13 through the third heat exchanger 15, resulting in that heat can be absorbed out of the air conditioning duct by the third heat exchanger 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a heating / cooling cycle having a cooling / heating function of an air conditioner used in a vehicle such as an electric vehicle.

[0002]

2. Description of the Related Art A cooling / heating cycle used in an air conditioner for an electric vehicle is disclosed in, for example, JP-A-59-494.
It is conceivable to use the heat pump type air conditioner disclosed in Japanese Patent Publication No. 39, Japanese Utility Model Publication No. 62-18484, etc., but in recent years, a sub-condenser is provided downstream of the evaporator (first heat exchanger) of the air conditioning duct. By providing a (second heat exchanger) and switching the three-way valve provided on the inflow side of the main condenser (third heat exchanger), the refrigerant flowing out of the compressor is transferred to the third heat exchanger during the cooling operation,
The second heat exchanger, the expansion valve, the first heat exchanger, and the compressor are circulated in this order, and the third heat exchanger is bypassed during the heating operation, so that the second heat exchanger, the expansion valve, the first heat exchanger, A system in which the compressor is circulated in order is considered.

In this system, during the heating operation, the refrigerant discharged from the compressor is radiated by the second heat exchanger in the air conditioning duct and is absorbed by the first heat exchanger in the same air conditioning duct. But
Since heat corresponding to the work of the compressor is added, the air in the air conditioning duct can be heated as a whole.

[0004]

However, in the system described above, there is no heat absorption from the outside of the air conditioning duct during the heating operation, and the heating capacity is secured only by the work of the compressor. However, the heating capacity itself was small.

Therefore, an object of the present invention is to provide a heating / cooling cycle of a vehicle air conditioner in which heating capacity is increased during heating operation.

[0006]

SUMMARY OF THE INVENTION However, the gist of the present invention is to provide a compressor and an expansion valve, an upstream first heat exchanger arranged in an air conditioning duct, and an air flow rate at an air mix door. Is adjusted and has at least a downstream second heat exchanger arranged inside the air conditioning duct and a third heat exchanger arranged outside the air conditioning duct, and the compressor and the expansion valve are connected to the third heat exchanger. A path connecting the exchanger and the second heat exchanger and connecting the expansion valve and the compressor via the first heat exchanger, and the compressor and the expansion valve on the second heat exchanger. And a path for connecting the expansion valve and the compressor via the third heat exchanger.

[0007]

Therefore, during the cooling operation, the refrigerant discharged from the compressor is guided to the expansion valve via the third heat exchanger and the second heat exchanger and returned to the compressor via the first heat exchanger. If the opening degree of the air mix door is reduced to eliminate the ventilation volume of the second heat exchanger, the refrigerant from the compressor is radiated by the third heat exchanger outside the air conditioning duct, and is decompressed by the expansion valve. After being first
The heat exchanger absorbs heat from the air in the air conditioning duct to cool the air introduced into the air conditioning duct.

Further, during the heating operation, the refrigerant discharged from the compressor is directly guided to the second heat exchanger, is sent to the expansion valve via the second heat exchanger, and is then guided to the third heat exchanger. By returning to the compressor via the third heat exchanger and increasing the opening of the air mix door to increase the ventilation volume of the second heat exchanger, the refrigerant from the compressor is After the heat is dissipated in the air conditioning duct by the second heat exchanger and the pressure is reduced by the expansion valve,
The heat exchanger absorbs heat from the air outside the air conditioning duct. Therefore, the air introduced into the air conditioning duct is not heat-exchanged in the first heat exchanger and is heated when passing through the third heat exchanger.

[0009]

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

FIG. 1 shows an air conditioner according to the present invention. The air conditioner is mounted on, for example, an electric vehicle, and an inside / outside air switching device 2 is provided on the most upstream side of an air conditioning duct 1. The inside air inlet 3 and the outside air inlet 4 are selectively opened by an intake door 5. The inside air or the outside air selectively introduced into the air conditioning duct 1 is sucked by the rotation of the blower 6 and is sent to the first heat exchanger 7 and the second heat exchanger 8 where it is heat-exchanged and is blown out as desired. It is designed to be supplied from the mouth into the passenger compartment. The second heat exchanger 8 is arranged on the downstream side of the first heat exchanger 7, and the amount of air passing therethrough can be varied by adjusting the opening degree of the air mix door 9.

The air mix door 9 has an opening of 100%.
Then, the ventilation amount of the second heat exchanger 8 is maximum, and the ventilation amount of the second heat exchanger 8 is minimum when the opening degree is 0%.

The outflow side of the second heat exchanger 8 is connected to the inflow side of the first heat exchanger 7 via a liquid tank 10, an expansion valve 11 and a first opening / closing valve 12, and the first heat exchanger is connected. The outflow side of 7 is connected to the suction side (B) of the compressor 13 by piping. The discharge side (A) of the compressor 13 is connected to the one end (C) of the third heat exchanger 15 arranged outside the air conditioning duct via the second opening / closing valve 14, and the third heat exchanger 15 The other end (D) is connected to the inflow side of the second heat exchanger 8 via the check valve 16.

Further, between the discharge side (A) of the compressor 13 and the outflow side of the check valve 16, there is a bypass passage 18 which is opened / closed by a third opening / closing valve 17 and bypasses the third heat exchanger 15. Piping is connected. Further, the third heat exchanger 1 is provided between the expansion valve 11 and the first opening / closing valve 12 via the check valve 19.
5 is connected to the other end (D) of 5, and one end (C) of the third heat exchanger 15 is connected to the suction side (B) of the compressor 13 via the fourth on-off valve 20.

Then, the open / close valves 12, 14, 17, 2
Various operating modes can be obtained by controlling the ON / OFF of 0 and the opening degree of the air mix door 9. Each operating mode will be described below.

First, the cooling operation mode will be described.
The second opening / closing valves 12 and 14 are opened, and the third and fourth opening / closing valves 1 are opened.
7 and 20 are closed and the opening degree of the air mix door 9 is 0%.
(The position shown by the solid line in the figure). Then, the refrigerant flowing out from the discharge side (A) of the compressor 13 enters the third heat exchanger 15 and radiates heat to the air outside the air conditioning duct to be condensed and liquefied, as shown by the flow of the solid line arrow. 2 reaches the heat exchanger 8. The refrigerant reaching the second heat exchanger 8 does not exchange heat with the air in the air conditioning duct because the ventilation to the second heat exchanger 8 is blocked by the air mix door 9. It passes through the container 8 and reaches the expansion valve 11 via the liquid tank 10. Then, it is decompressed by the expansion valve 11 and sent to the first heat exchanger 7, where it absorbs heat from the air in the air conditioning duct to be evaporated and vaporized, and is returned to the suction side (B) of the compressor 13. For this reason, the air sent from the upstream of the air conditioning duct 1 is cooled by the first heat exchanger 7, bypasses the second heat exchanger 8, and is supplied as it is to the vehicle interior.

On the other hand, in the heating operation mode, the first and second on-off valves 12 and 14 are closed, and the third and fourth on-off valves are closed.
The opening / closing valves 17 and 20 are opened, and the opening degree of the air mix door 9 is set to, for example, 100% (the position shown by the alternate long and short dash line in the figure). In this case, the discharge side of the compressor 13 (A)
The refrigerant flowing out of the
It bypasses the heat exchanger 15 and enters the second heat exchanger 8, where it radiates heat to the air in the air conditioning duct to condense and liquefy, and reaches the expansion valve 11 via the liquid tank 10. Then, the pressure is reduced by the expansion valve 11 and sent to the third heat exchanger 15, where heat is taken from the air outside the air conditioning duct and returned to the suction side (B) of the compressor 13. Therefore, the air sent from the upstream of the air conditioning duct 1 passes through the first heat exchanger 7, but is not cooled because the refrigerant does not flow and is guided to the second heat exchanger 8 by the air mix door 9. Then, it is heated here and supplied as it is into the passenger compartment.

When desiring heating operation is desired, the second
The on-off valve 14 is closed, and the first, third and fourth on-off valves 12, 1
7, 20 are opened, and the opening degree of the air mix door 9 is set to, for example, an intermediate position (position shown by a broken line in the figure). In this case, the refrigerant flowing out from the discharge side (A) of the compressor 13 is the third heat exchanger 15 as shown by the flow of the broken line arrow.
To the second heat exchanger 8, where heat is radiated to the air in the air conditioning duct to condense and liquefy, and the liquid tank 10
To the expansion valve 11 via. Then, the refrigerant that has been decompressed by the expansion valve 11 and is sent to the third heat exchanger 15 is sent to the second heat exchanger 7 and is sent to the third heat exchanger 15,
The refrigerant that absorbs heat from the air outside the air conditioning duct and is returned to the suction side (B) of the compressor 13 and that is sent to the second heat exchanger 7 absorbs heat from the air inside the air conditioning duct and is the suction side of the compressor 13. Returned to (B). For this reason, the air sent from the upstream of the air conditioning duct 1 is dehumidified when passing through the first heat exchanger 7, and a part of the air is guided to the second heat exchanger 8 by the air mix door 9, where The heated and dried hot air having a desired temperature is supplied to the passenger compartment.

In this embodiment, the space between the expansion valve 11 and the first on-off valve 12 is connected to the other end (D) of the third heat exchanger 15 via the check valve 19, and One end (C) of the No. 3 heat exchanger 15 is connected to the suction side (B) of the compressor 13 through the fourth opening / closing valve 20 by piping, but as shown in FIG. The first open / close valve 12 is connected to one end (C) of the third heat exchanger 15 via the check valve 19, and the other end (D) of the third heat exchanger 15 is connected to the fourth open / close valve 20. Through the suction side of the compressor 13 (B)
The same operation and effect can be obtained by connecting to (2nd embodiment).

However, in the above-mentioned two embodiments, the third heat exchanger 15 is used both as a condenser and as an evaporator, so the piping configuration of FIG. 1 is preferable. That is, in the condenser, the refrigerant can be condensed and liquefied so that the diameter on the refrigerant outlet side is smaller than the diameter on the refrigerant inlet side.However, in the evaporator, the refrigerant flows out due to the evaporation and vaporization of the refrigerant. It is desirable that the diameter on the side of the refrigerant be larger than that on the side of the refrigerant inflow. Therefore, it is desirable to reverse the flow of the refrigerant between the case of using the condenser and the case of using the evaporator. In the configuration of FIG. 2, the case of using the third heat exchanger 15 as the condenser and the case of using the evaporator. Since the flow of the refrigerant is the same as when used as, if the heat exchanger is designed centering on one of the functions, when used as the other function, the passage resistance becomes large, and the heat exchange efficiency is increased. There are inconveniences such as deterioration.

Further, in FIG. 1, the liquid tank 1
The expansion valve 11 and the first on-off valve 12 are provided on the outflow side of 0, and the third heat exchanger 15 is provided between the expansion valve 11 and the first on-off valve 12.
By connecting to the other end (D) of the
Although one expansion valve 11 is shared by the first and third heat exchangers 7 and 15, as shown in FIG. 3, the outflow side of the liquid tank 10 is connected via the first opening / closing valve 12 and the expansion valve 21. The same action and effect can be obtained by connecting the first heat exchanger 7 and the other end (D) of the third heat exchanger 15 via the expansion valve 22 and the check valve 19 ( Third embodiment).

In particular, according to the piping configuration of FIG. 1, if the resistances of the paths on the first heat exchanger side and the paths on the third heat exchanger side are not balanced during the dehumidifying and heating operation, the refrigerant is biased to one side. Although there is a possibility that the refrigerant will flow, if the configuration shown in FIG. 3 is used, even if the resistances of the respective paths are not balanced, it is possible to supply the refrigerant that matches the resistances of the respective paths, and there is no uneven flow of the refrigerant. Has merits.

In the structure shown in FIG. 3, the first opening / closing valve 12
It goes without saying that the arrangement order of the expansion valve 21 and the expansion valve 21 and the arrangement order of the expansion valve 22 and the check valve 19 may be reversed.

FIG. 4 shows a fourth embodiment according to the present invention.

In this embodiment, the discharge side (A) of the compressor 13 is connected to the inflow side of the second heat exchanger 8,
The outflow side of the second heat exchanger 8 is connected via a fifth opening / closing valve 25 to one end (C) of the third heat exchanger 15 arranged outside the air conditioning duct. The other end (D) of the third heat exchanger 15 is connected to the expansion valve 11 via the check valve 26 and the liquid tank 10, and the expansion valve 11 is the sixth valve.
It is connected to the inflow side of the first heat exchanger 7 via the on-off valve 27, and the outflow side of the first heat exchanger 7 is connected to the suction side (B) of the compressor 13 by piping.

Further, between the outflow side of the second heat exchanger 8 and the inflow side of the liquid tank 10, there is a bypass passage 18 which is opened / closed by the seventh on-off valve 28 and bypasses the third heat exchanger 15. Piping is connected. Further, the third heat exchanger 1 is provided between the expansion valve 11 and the sixth opening / closing valve 27 via a check valve 29.
5 is connected to the other end (D) of 5, and one end (C) of the third heat exchanger 15 is connected to the suction side (B) of the compressor 13 via the eighth opening / closing valve 30.

The open / close valves 25, 27, 28, 3
Various operating modes can be obtained by controlling the ON / OFF of 0 and the opening degree of the air mix door 9. Each operating mode will be described below.

First, the cooling operation mode will be described.
Open the sixth opening / closing valves 25, 27, and open the seventh and eighth opening / closing valves 2
8 and 30 are closed and the opening degree of the air mix door 9 is 0%.
(The position shown by the solid line in the figure). Then, the refrigerant flowing out from the discharge side (A) of the compressor 13 directly enters the second heat exchanger 8 as shown by the flow of the solid line arrow. In this operation mode, since the ventilation to the second heat exchanger 8 is blocked by the air mix door 9, the refrigerant that has not reached the second heat exchanger 8 without exchanging heat with the air in the air conditioning duct is
It passes through here and reaches the third heat exchanger 15, where heat is radiated to the air outside the air conditioning duct to be condensed and liquefied. Then, the refrigerant that has passed through the third heat exchanger 15 is the liquid tank 1
0 to the expansion valve 11, which is decompressed by the expansion valve 11 and sent to the first heat exchanger 7, where it absorbs heat from the air in the air-conditioning duct to evaporate and evaporate, and the suction side (B ). Therefore, the air sent from the upstream side of the air conditioning duct 1 is cooled by the first heat exchanger 7, bypasses the second heat exchanger 8, and is supplied to the vehicle interior as it is.

On the other hand, during the heating operation, the fifth and sixth on-off valves 25 and 27 are closed, the seventh and eighth on-off valves 28 and 30 are opened, and the opening degree of the air mix door 9 is set to, for example, It is set to 100% (the position shown by the alternate long and short dash line in the figure).
In this case, the refrigerant flowing out from the discharge side (A) of the compressor 13 enters the second heat exchanger 8 as shown by the flow of the dashed arrow, and radiates heat to the air in the air conditioning duct to be condensed and liquefied. , Bypassing the third heat exchanger 15 and enters the liquid tank 10. Then, the pressure is reduced by the expansion valve 11 and sent to the third heat exchanger 15, where heat is taken from the air outside the air conditioning duct and returned to the suction side (B) of the compressor 13.
Therefore, the air sent from the upstream side of the air conditioning duct 1 passes through the first heat exchanger 7, but is not cooled because the refrigerant does not flow, and is not cooled by the air mix door 9.
It is guided to the heat exchanger 8, where it is heated and directly supplied into the vehicle interior.

When desiring heating operation is desired, the fifth
The on-off valve 25 is closed, and the sixth, seventh and eighth on-off valves 27, 2
8 and 30 are opened, and the opening degree of the air mix door 9 is set to, for example, an intermediate position (position shown by a broken line in the figure). In this case, the refrigerant flowing out from the discharge side (A) of the compressor 13 enters the second heat exchanger 8 where it radiates heat to the air in the air conditioning duct to be condensed and liquefied, and then the expansion valve via the liquid tank 10. To 11. Then, while being decompressed by the expansion valve 11 and being sent to the third heat exchanger 15, the refrigerant sent to the first heat exchanger 7 and sent to the third heat exchanger 15 is transferred from the air outside the air conditioning duct. The refrigerant that absorbs heat and is returned to the suction side (B) of the compressor 13 and that is sent to the second heat exchanger 7 absorbs heat from the air in the air conditioning duct, and the compressor 1
3 is returned to the suction side (B). Therefore, the air conditioning duct 1
The air sent from the upstream side of is dehumidified when passing through the first heat exchanger 7, and a part of the air is guided to the second heat exchanger 8 by the air mix door 9 where it is heated and dried. It is supplied to the vehicle interior as warm air of a desired temperature.

In this embodiment, the space between the expansion valve 11 and the sixth on-off valve 27 is connected to the other end (D) of the third heat exchanger 15 via the check valve 29, and One end (C) of the No. 3 heat exchanger 15 is connected to the suction side (B) of the compressor 13 through the eighth opening / closing valve 30 by piping, but as shown in FIG. The sixth open / close valve 27 is connected to one end (C) of the third heat exchanger 15 via the check valve 29, and the other end (D) of the third heat exchanger 15 is connected to the eighth open / close valve 30. Through the suction side of the compressor 13 (B)
The same operation and effect can be obtained by connecting to (5th embodiment).

However, in the above-mentioned two embodiments, the third heat exchanger 15 is used both as a condenser and as an evaporator, and therefore the piping configuration of FIG. 4 is preferable for the above-mentioned reason.

Further, in FIG. 4, the liquid tank 1
The expansion valve 11 and the sixth opening / closing valve 27 are provided on the outflow side of 0, and the third heat exchanger 15 is provided between the expansion valve 11 and the sixth opening / closing valve 27.
By connecting to the other end (D) of the
Although one expansion valve 11 is shared by the first and third heat exchangers 7 and 15, as shown in FIG. 6, the outflow side of the liquid tank 10 is connected via the sixth opening / closing valve 27 and the expansion valve 21. The same operation and effect can be obtained by connecting to the first heat exchanger 7 and also to the other end (D) of the third heat exchanger 15 via the expansion valve 22 and the check valve 29 ( Sixth embodiment).

In particular, according to the piping configuration of FIG. 4, if the resistances of the paths on the first heat exchanger side and the paths on the third heat exchanger side are not balanced during the dehumidifying and heating operation, the refrigerant is biased to one side. Although there is a possibility that the refrigerant may flow, if the configuration shown in FIG. 6 is used, it is possible to supply the refrigerant corresponding to the resistance of each path even if the resistance of each path is not balanced, and there is also an advantage that the drift of the refrigerant is eliminated. Have

In the structure shown in FIG. 6, the sixth opening / closing valve 27
It goes without saying that the arrangement order of the expansion valve 21 and the expansion valve 21 and the arrangement order of the expansion valve 22 and the check valve 29 may be reversed.

[0035]

As described above, according to the present invention,
The first and second heat exchangers are provided inside the air conditioning duct, the third heat exchanger is provided outside the air conditioning duct, and the heat exchange medium from the compressor is guided to the expansion valve via the second and third heat exchangers. In contrast to the cycle in which the expansion valve returns to the compressor via the first heat exchanger, during the heating operation, the heat exchange medium from the compressor is guided to the expansion valve via the second heat exchanger, and the expansion valve Since it is possible to select a route that returns to the compressor via the third heat exchanger, it is possible to absorb heat from outside the air conditioning duct as well, thereby improving heating efficiency and improving heating capacity. It is a thing.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a cooling / heating cycle of a vehicle air conditioner according to the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the cooling / heating cycle of the vehicle air conditioner according to the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of the cooling / heating cycle of the vehicle air conditioner according to the present invention.

FIG. 4 is a schematic configuration diagram showing a fourth embodiment of the cooling / heating cycle of the vehicle air conditioner according to the present invention.

FIG. 5 is a schematic configuration diagram showing a fifth embodiment of the cooling / heating cycle of the vehicle air conditioner according to the present invention.

FIG. 6 is a schematic configuration diagram showing a sixth embodiment of the cooling / heating cycle of the vehicle air conditioner according to the present invention.

[Explanation of symbols]

 1 Air-conditioning duct 7 1st heat exchanger 8 2nd heat exchanger 9 Air mix door 11, 21, 22 Expansion valve 13 Compressor 15 3rd heat exchanger

Claims (1)

[Claims] 1. A compressor and an expansion valve, a first heat exchanger on the upstream side arranged in an air conditioning duct, and a second ventilation on the downstream side arranged in the air conditioning duct, the ventilation amount of which is adjusted by an air mix door. It has at least a heat exchanger and a third heat exchanger arranged outside the air conditioning duct, and connects the compressor and the expansion valve via the third heat exchanger and the second heat exchanger, A path connecting the expansion valve and the compressor via the first heat exchanger, a path connecting the compressor and the expansion valve via the second heat exchanger, and a path connecting the expansion valve and the compressor to the first heat exchanger. A cooling / heating cycle for a vehicle air conditioner, comprising: a path connected through a heat exchanger.