JP3433297B2 - Air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of having a dehumidifying function by two heat exchangers arranged in an air conditioning path.

[0002]

2. Description of the Related Art Conventionally, as an air conditioner having a dehumidifying function at the time of heating, there is known one disclosed in Japanese Patent Publication No. 52-13025. As shown in FIG. 5, one end of the first heat exchanger B arranged on the upstream side of the air conditioning path A and one end of the second heat exchanger C arranged on the downstream side of the same path. Are connected in series via the decompression decompression / expansion mechanism D, and the other end of the first heat exchanger B is connected to the second heat exchanger C.
A compressor E, a third heat exchanger F arranged outside the air conditioning path, a heating decompression / expansion mechanism G, and an opening / closing valve M are sequentially connected to the other end of the. A four-way valve H is provided in the middle of the piping between the first and third heat exchangers B and F and the compressor E so that the flow of the refrigerant pressure-fed from the compressor E can be reversed. Has become. In addition, a check valve I is attached to the decompression decompression mechanism D for dehumidification.
Are arranged in parallel, and a cooling decompression expansion mechanism N is provided between the second heat exchanger C and one end of the on-off valve M, and a cooling decompression expansion mechanism N is provided between the first heat exchanger B and the other end of the on-off valve M. An on-off valve O is provided. Further, the check valve J and the dehumidification decompression expansion mechanism K connected in parallel to the heating decompression expansion mechanism G, and the third heat exchanger F and the heating decompression expansion mechanism G were connected in parallel. A check valve L and an opening / closing valve P connected in parallel to the dehumidifying decompression / expansion mechanism K are provided.

In such a structure, during cooling operation,
The open / close valves O and P are opened, the open / close valve M is closed, and the four-way valve is set as shown by the solid line. During the dehumidifying and cooling operation, the open / close valves M and P are opened and the open / close valve O is closed, and the four-way valve is also shown by the solid line. To set. Also, when operating during heating, the on-off valves O and P are closed,
Open the on-off valve M, set the four-way valve as shown by the broken line,
During the dehumidifying heating operation, the on-off valve M is opened, the on-off valves O and P are closed, and the four-way valve is set as shown by the solid line.

[0004]

However, in the above-mentioned technique, switching between cooling, dehumidifying and cooling, heating, and dehumidifying and heating is realized by a cycle having a large number of on-off valves and expansion mechanisms, and therefore the structure of the cycle itself. Becomes complicated and
Further, since the four-way valve is used for switching the air conditioning mode, the pressure loss of the refrigerant becomes large, and there is a drawback that the high-temperature refrigerant and the low-temperature refrigerant flowing through the four-way valve exchange heat at this four-way valve. It was

In order to overcome the above-mentioned drawbacks, the present invention provides an air conditioner which does not require a four-way valve and has a simple structure capable of switching between air conditioning modes of cooling, dehumidifying and cooling, heating and dehumidifying and heating. The challenge is to provide.

[0006]

SUMMARY OF THE INVENTION Therefore, the gist of the invention of claim 1 is that the first heat of which the ventilation amount is adjusted by the compressor and the first damper arranged in the air conditioning duct. An exchanger, a second heat exchanger whose ventilation amount is adjusted by a second damper arranged in the air conditioning duct, a third heat exchanger arranged outside the air conditioning duct, an expansion valve and this A first and a second refrigerant flow rate adjusting circuit having an on-off valve for opening and closing a passage bypassing the expansion valve, the compressor, the first heat exchanger, the first refrigerant flow rate adjusting circuit, and the third refrigerant flow rate adjusting circuit. The cycle is configured in the order of the heat exchanger, the second refrigerant flow rate adjusting circuit, and the second heat exchanger.

Further, the gist of the invention according to claim 2 is that a compressor and a first heat exchanger which is arranged on a downstream side in an air conditioning duct and whose ventilation amount is adjusted by a first damper, A second heat exchanger which is arranged on the upstream side in the air conditioning duct and whose ventilation amount is adjusted by a second damper, a third heat exchanger which is arranged outside the air conditioning duct, an expansion valve and this expansion. First equipped with an on-off valve for opening and closing a passage bypassing the valve
And a second refrigerant flow rate adjusting circuit, and the compressor, the first heat exchanger, the first refrigerant flow rate adjusting circuit, the third heat exchanger, the second refrigerant flow rate adjusting circuit, the second heat. The connection is made in the order of the exchangers, and a bypass path for bypassing the second heat exchanger is provided, and the bypass path is opened and closed by an opening / closing valve.

[0008]

Therefore, in the first aspect of the invention, the opening / closing valve of the first refrigerant flow rate adjusting circuit is opened during the cooling operation.
The on-off valve of the second refrigerant flow control circuit is closed, and the first damper is set at the minimum ventilation amount position of the first heat exchanger and the second damper is set at the maximum ventilation amount position of the second heat exchanger. if,
The refrigerant discharged from the compressor passes through the first heat exchanger without radiating heat, passes through the on-off valve of the first refrigerant flow control circuit, radiates heat in the third heat exchanger, and then the second refrigerant. After the pressure is reduced by the expansion valve of the flow rate control circuit, heat is absorbed by the second heat exchanger. In this case, the first heat exchanger has the minimum ventilation volume,
Since the second heat exchanger has the largest ventilation volume, the air sent from the upstream in the air conditioning duct is cooled when passing through the second heat exchanger.

During the dehumidifying and cooling operation, the opening / closing valve of the first refrigerant flow rate adjusting circuit is opened, the opening / closing valve of the second refrigerant flow rate adjusting circuit is closed, and the first damper is connected to the middle of the first heat exchanger. If the second damper is set to the maximum ventilation position of the second heat exchanger at the ventilation position, the refrigerant discharged from the compressor is cooled only in the first heat exchanger except in the cooling operation. It uses the same heat exchange mechanism as at times. In this case, since the first heat exchanger has a certain amount of ventilation and the second heat exchanger has the maximum ventilation, the air sent from the upstream side is the second heat exchanger. Although it is cooled and dehumidified when passing through the first heat exchanger and a part of it is heated by the first heat exchanger, it becomes a cooling only.

During the heating operation, the opening / closing valve of the first refrigerant flow rate adjusting circuit is closed and the opening / closing valve of the second refrigerant flow rate adjusting circuit is opened, and the first damper is moved to the maximum ventilation position of the first heat exchanger. Then, if the second damper is set at the minimum ventilation amount position of the second heat exchanger, the refrigerant discharged from the compressor radiates heat in the first heat exchanger and the expansion of the first refrigerant flow rate adjusting circuit. After the pressure is reduced by the valve, the heat is absorbed by the third heat exchanger, passes through the on-off valve of the second refrigerant flow rate control circuit, and passes through the second heat exchanger without absorbing heat. In this case, since the first heat exchanger has the maximum ventilation amount and the second heat exchanger has the minimum ventilation amount, the air sent from the upstream in the air conditioning duct is the first heat exchanger. Is heated as it passes through.

Further, during the dehumidifying and heating operation, the opening / closing valve of the first refrigerant flow rate adjusting circuit is closed, and the opening / closing valve of the second refrigerant flow rate adjusting circuit is opened to make the first damper the maximum of the first heat exchanger. If the second damper is set at the position of the ventilation volume at the position of the intermediate ventilation of the second heat exchanger, the refrigerant discharged from the compressor takes the same heat exchange mechanism as during the heating operation. In this case, the air volume of the first heat exchanger is the maximum and the air volume of the second heat exchanger has a certain level, so that the air sent from the upstream side passes through the second heat exchanger. When passing, it is dehumidified and then heated in the first heat exchanger to become hot air as a whole dried.

On the other hand, in the invention described in claim 2, in addition to the operation of the invention described in claim 1, the opening / closing valve of the bypass path is closed during the cooling operation or the dehumidifying cooling operation, but the heating operation is performed. At this time, the on-off valve is opened, and the refrigerant flowing out from the third heat exchanger is directly returned to the compressor,
The supply of the refrigerant to the heat exchanger is suppressed. Further, during the dehumidifying and heating operation, the bypass path is opened / closed as necessary.

[0013]

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

1 (a) and 1 (b), an air conditioner according to the present invention is shown. The air conditioner is mounted on, for example, an automobile, and includes first and first air conditioners arranged in an air conditioning duct 1. It is provided with two heat exchangers 2 and 3 and a third heat exchanger 4 arranged outside the air conditioning duct 1.

An inside / outside air switching device is provided on the most upstream side of the air conditioning duct 1, and the inside air inlet and the outside air inlet are selectively opened by an intake door. The inside air or the outside air selectively introduced into the air conditioning duct 1 is sucked by the rotation of the blower, sent to the first and second heat exchangers 2 and 3, where heat is exchanged there from a desired outlet. It is designed to be supplied to the passenger compartment. In addition, in this embodiment, the first heat exchanger 2 is arranged downstream of the second heat exchanger 3.

First and second dampers 5 and 6 are provided on the upstream sides of the first and second heat exchangers 2 and 3, respectively. By adjusting the opening of the second damper 6, By changing the ratio of the air passing through the second heat exchanger 3 and the air bypassing the second heat exchanger 3, and by adjusting the opening of the first damper 5, the first heat The ratio of the air passing through the exchanger 2 and the air bypassing the first heat exchanger 2 is changed so that the air conditioning state can be changed.

Here, the second damper 6 is variable from the I position (opening 100%) where the amount of air passing through the second heat exchanger 3 is maximum to the minimum II position (opening 0%). The first damper 5 can be minimized from the position III (opening 100%) where the air volume passing through the first heat exchanger 2 is maximum.
It can be changed to the IV position (opening 0%).

One end 2a of the first heat exchanger 2 is connected to the discharge side A of the compressor 7, and the other end 2b is an expansion valve 9 and an opening / closing valve 8 for opening and closing a passage bypassing the expansion valve 9. Is connected to one end 10a of the first refrigerant flow rate adjusting circuit 10 including. Further, one end 3a of the second heat exchanger 3 is connected to the suction side B of the compressor 7, and the other end 3b thereof is an opening / closing valve 11 for opening / closing an expansion valve 12 and a passage bypassing the expansion valve 12.
It is connected to one end 13a of the second refrigerant flow rate adjusting circuit 13 including the. The third heat exchanger 4 has one end 4a connected to the other end 10b of the first refrigerant flow rate adjusting circuit 10 and the other end 4b connected to the other end 13b of the second refrigerant flow rate adjusting circuit 13. ing.

The opening and closing of the on-off valves 8 and 11 and the opening degrees of the first and second dampers 5 and 6 are controlled by the control unit 20.
It is controlled by the control signal from. The control unit 20 is a known unit having an input circuit including an A / D converter, a multiplexer, etc., an arithmetic processing circuit including a ROM, a RAM, a CPU, etc., and an output circuit including a drive circuit, etc., and sets an air conditioning mode. Setting signals and the like are input, and these signals are processed according to a predetermined program.

Next, of the control operations by the control unit 20, a specific control operation example of the on-off valves 8 and 11 and the first and second dampers 5 and 6 will be described.

First, when the air conditioning mode is set to the cooling mode, the control unit 20 opens the on-off valve 8 and closes the on-off valve 11, and the first damper 5 as shown in FIG. To the IV position and the second damper 6 to the I position. Therefore, the compressed refrigerant flowing out from the discharge side A of the compressor 7 does not radiate heat in the first heat exchanger 2 and passes through the opening / closing valve 8 of the first refrigerant flow rate control device 10 to the third heat exchanger 4 The heat is released (condensed and liquefied) there, and the pressure is reduced by the expansion valve 12 of the second refrigerant flow rate control device 13 to the second heat exchanger 3, where the heat is absorbed (evaporated and evaporated).
Then, it is returned to the compressor 7. Therefore, the air sent from the upstream side is cooled by the second heat exchanger 3, bypasses the first heat exchanger 2, and is supplied into the vehicle interior.

On the other hand, when the air conditioning mode is set to the dehumidifying and cooling mode, as shown in FIG. 2, the control unit 20 opens the on-off valve 8 and opens and closes the on-off valve 11 as in the cooling operation. Close it. In addition, the second damper 6 is set to I
The first damper 5 is set in the intermediate position between the III and IV positions. Therefore, the compressed refrigerant flowing out from the discharge side A of the compressor 7 is radiated (condensed and liquefied) by the first heat exchanger 2, and then the third refrigerant is passed through the opening / closing valve 8 of the first refrigerant flow rate control device 10. Reaching the heat exchanger 4,
The heat is again radiated (condensed and liquefied) here, the pressure is reduced by the expansion valve 12 of the second refrigerant flow rate control device 13 and reaches the second heat exchanger 3, where the heat is absorbed (evaporated and vaporized) and then the compressor 7 is discharged.
Returned to. Therefore, the air sent from the upstream is
It is cooled in the second heat exchanger 3, a part of it passes through the first heat exchanger 2, and the temperature that has dropped too much due to the dehumidifying action of the second heat exchanger 3 is returned to the original state and enters the vehicle interior. Supplied.

When the air conditioning mode is set to the heating mode, as shown in FIG.
0 closes the open / close valve 8 and opens the open / close valve 11, sets the first damper 5 to the III position, and sets the second damper 6 to the II position. Therefore, the compressed refrigerant flowing out from the discharge side A of the compressor 7 radiates heat (condensation and liquefaction) in the first heat exchanger 2, and is decompressed by the expansion valve 9 of the first refrigerant flow rate control device 10 to be the third refrigerant. Opening valve 1 of second refrigerant flow rate control device 13 after reaching heat exchanger 4 and absorbing heat (evaporating)
It reaches the second heat exchanger 3 via 1 and is returned to the compressor 7. Therefore, the air sent from the upstream bypasses the second heat exchanger 3, is heated by the first heat exchanger 2, and is supplied into the vehicle interior.

When the air conditioning mode is set to the dehumidification heating mode, the control unit 20 closes the open / close valve 8 and opens the open / close valve 11 as in the heating operation, as shown in FIG. . Also, the first damper 5 is set to the III position, but the second damper 6 is set to the intermediate position between the I position and the II position. Therefore, the compressed refrigerant flowing out from the discharge side A of the compressor 7 is the same as in the heating operation.
Heat is dissipated (condensed and liquefied) in the first heat exchanger 2, decompressed by the expansion valve 9 of the first refrigerant flow rate control device 10 and reaches the third heat exchanger 4, where heat is absorbed (evaporated and vaporized). After that, it reaches the second heat exchanger 3 via the opening / closing valve 11 of the second refrigerant flow rate control device 13, where it again absorbs heat (evaporates) and is returned to the compressor 7. Therefore, a part of the air sent from the upstream enters the second heat exchanger 3 to be dehumidified, is heated when passing through the first heat exchanger 2, and is supplied into the vehicle interior. .

With respect to the above-mentioned cycle path, as shown in FIGS. 5 and 6, from the third heat exchanger 4 and the second refrigerant flow rate adjusting circuit 13 to the low pressure side B of the compressor 7. Alternatively, the second heat exchanger 3 may be substantially bypassed, and the bypass path 16 opened and closed by the opening / closing valve 15 may be provided. In such a configuration, in addition to the above-described control, the opening / closing valve 15 is operated during the cooling operation or the dehumidifying cooling operation.
Is closed, but during heating operation, this path 16 is opened to directly return the refrigerant flowing out of the third heat exchanger 4 to the compressor 7, and the second heat exchanger 3 which is not heat-exchanged with the air in the air-conditioning duct. It is also possible to suppress the supply of the refrigerant to the. Further, during the dehumidifying heating operation, the opening / closing valve 15 is controlled to be opened / closed to, for example, the temperature of the second heat exchanger 3, or
The second heat exchanger 3 may be prevented from freezing by closing the air when the temperature of the air passing through the heat exchanger 3 is equal to or lower than a predetermined temperature and opening the air in other cases.

[0026]

As described above, according to the first and second aspects of the present invention, the first and second refrigerant flow rate adjusting circuits in which the on-off valve and the expansion valve are arranged in parallel are provided in the first heat source. It is interposed between the heat exchanger and the third heat exchanger and between the second heat exchanger and the third heat exchanger, respectively, and the passing air volumes of the first and second heat exchangers are set to the first and second heat exchangers. Since it can be changed by the second damper and the second damper, it is possible to switch between cooling, dehumidifying cooling, heating, and dehumidifying heating by adjusting the opening / closing of the expansion valve and the opening of the damper without using the four-way valve. it can. Further, the elimination of the four-way valve simplifies the cycle structure and eliminates the heat exchange generated by the four-way valve.

In particular, according to the second aspect of the invention, since the supply of the refrigerant to the second heat exchanger can be suppressed during the heating operation, the cycle is constituted only by the heat exchangers that need heat exchange. can do. Further, during the dehumidifying and heating operation, the supply of the refrigerant to the second heat exchanger can be interrupted, so that there is an advantage that the second heat exchanger can be prevented from freezing.

[Brief description of drawings]

FIG. 1 (a) is a configuration diagram of an air conditioner according to a first aspect of the invention during a cooling operation, and FIG.
[Fig. 4] is an explanatory view showing a damper position during a cooling operation.

2 (a) is a configuration diagram of the air conditioner according to the invention of claim 1 during dehumidifying and cooling operation, and FIG.
(B) is explanatory drawing which shows the damper position at the time of dehumidification cooling operation.

FIG. 3 (a) is a configuration diagram of the air conditioning apparatus according to the first aspect of the present invention during heating operation, and FIG.
[Fig. 4] is an explanatory view showing a damper position during heating operation.

FIG. 4 (a) is a configuration diagram of the air conditioner according to the invention of claim 1 during dehumidifying and heating operation, and FIG.
(B) is explanatory drawing which shows the damper position at the time of dehumidification heating operation.

FIG. 5 is an explanatory view showing an air conditioner according to a second aspect of the invention.

FIG. 6 is an explanatory view showing another embodiment of the air conditioner according to the invention described in claim 2.

FIG. 7 is a configuration diagram showing a conventional air conditioner.

[Explanation of symbols]

1 air conditioning duct 2 First heat exchanger 3 Second heat exchanger 4th heat exchanger 5 First damper 6 Second damper 7 compressor 8, 11, 15 on-off valve 9,12 Expansion valve 10 First Refrigerant Flow Rate Control Circuit 13 Second Refrigerant Flow Rate Control Circuit 16 Bypass route

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-96931 (JP, A) JP-A-60-15217 (JP, A) JP-A-60-15215 (JP, A) JP-A-4-15 151324 (JP, A) Actually open 62-138159 (JP, U) Actually open 61-7686 (JP, U) Actually open 58-177755 (JP, U) Actually open 3-115361 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60H 1/00 102 F25B 29/00 411

Claims (2)

(57) [Claims] 1. A compressor, a first heat exchanger whose ventilation amount is adjusted by a first damper arranged in the air conditioning duct, and a ventilation amount adjusted by a second damper arranged in the air conditioning duct. A second heat exchanger, a third heat exchanger arranged outside the air-conditioning duct, an expansion valve and an on-off valve for opening and closing a passage bypassing the expansion valve. A refrigerant flow rate adjusting circuit, the compressor, a first heat exchanger, a first refrigerant flow rate adjusting circuit, a third heat exchanger,
An air conditioner characterized in that a cycle is configured in the order of a second refrigerant flow rate adjusting circuit and a second heat exchanger. 2. A compressor, a first heat exchanger which is arranged on the downstream side in the air conditioning duct and whose ventilation amount is adjusted by a first damper, and a second heat exchanger which is arranged on the upstream side in the air conditioning duct. A second heat exchanger whose ventilation volume is adjusted by a damper, a third heat exchanger arranged outside the air conditioning duct, an expansion valve and an opening / closing valve for opening and closing a passage bypassing the expansion valve are provided. A first and a second refrigerant flow rate adjusting circuit, the compressor, the first heat exchanger, a first refrigerant flow rate adjusting circuit,
A third heat exchanger, a second refrigerant flow rate adjusting circuit, and a second heat exchanger are connected in this order, and a bypass path that bypasses the second heat exchanger is provided, and this bypass path is formed by an on-off valve. An air conditioner characterized by being opened and closed.