JPH05157407A - Air conditioner - Google Patents

Abstract

PURPOSE:To rapidly carry out transfer to dehumidifying operation caused by a change in temperature sensing of a shape memory spring used in an air conditioner which makes dehumidifying operation by cooling and heating of the room air and, at the same time, employs a shape memory spring for valve used for dehumidifying operation. CONSTITUTION:The subject air conditioner is constituted to start dehumidifying operation by closing a valve 10 by the shrinkage and deformation at the time of cooling of a shape memory spring that is used for the valve 10. With this constitution a valve controller 20 is provided so that, at the time of starting the dehumififying operation, the blast to a feat exchanger 5 in the room is stopped with room cooling operation being made in the room and the valve travel of an electrically-driven expansion valve 4 is reduces gradually, and a gas and liquid mixture or liquid refrigerant of temperature further lower than in room cooling flows through the valve 10.

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 cooling and dehumidifying operations.

[0002]

2. Description of the Related Art A conventional air conditioner capable of dehumidifying operation (see, for example, Japanese Utility Model Laid-Open No. 3-27571) will be described with reference to FIG. This air conditioner includes a compressor 51
The refrigerant discharged from is condensed in the outdoor heat exchanger 52 and is evaporated in the indoor heat exchanger 53 to perform the cooling operation, while the refrigerant is circulated contrary to the above to perform the heating operation. There is. In this case, the indoor heat exchanger 53 has two heat exchangers 53a for performing the dehumidifying operation,
The heat exchangers 53a and 53 are configured to be divided into 53b.
A parallel circuit of the on-off valve 54 and the capillary tube 55 is provided between b. As shown in FIG. 6, the on-off valve 54 includes a shape memory spring 56, a bias spring 57, a spacer 58 that moves according to the magnitude relationship between the forces of the springs 56, 57, and a spacer 58 slidably supported by the spacer 58. When the low temperature refrigerant flows, the shape memory spring 56 is in the contracted state and opens as shown in FIG. 6, while the high temperature refrigerant flows, the shape memory spring 56 is opened. In the extended state, the valve is closed as shown in FIG.

When the dehumidifying operation is performed in the air conditioner, the refrigerant discharged from the compressor 51 is supplied to the outdoor heat exchanger 52 (the outdoor fan 60 is OFF), and the refrigerant also stores heat in the bypass passage 61. It is reheated via the exchanger 62 and is supplied to the indoor heat exchanger 53. Then, the shape memory spring 56 of the opening / closing valve 54 expands and closes (FIG. 7), and the refrigerant flows through the capillary tube 55. As a result, the indoor heat exchanger 53a on the upstream side is condensed, and the indoor heat exchanger 5 on the downstream side is condensed.
Evaporation will occur in 3b, whereby the room air will be cooled to dehumidify, and then the dehumidification operation of heating the dehumidified air to about room temperature and returning it to the room can be performed. The valve body 59 of the on-off valve 54 in the air conditioner moves in the valve opening direction due to the flow of the refrigerant during the heating operation, so that the valve closing operation due to the temperature rise is prevented.

[0004]

The air conditioner, however, has a drawback that it takes a relatively long time to shift the opening / closing valve 54 to the dehumidifying operation to close the valve. This is because the shape memory spring 56 is configured to be heated by the gas refrigerant having a small heat capacity, so that a sufficient temperature rising speed cannot be obtained. Further, when the heat storage heat exchanger 62 is used in the above-described manner for the purpose of performing the valve closing operation promptly, the electromagnetic valve 63 provided in the bypass passage 61 needs to be a reversible type. However, this causes an increase in the cost of the device.

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to provide an air conditioner capable of performing a quick shift to the dehumidifying operation without complicating the apparatus configuration. To provide a machine.

[0006]

Therefore, in the air conditioner of claim 1, the compressor 1, the outdoor heat exchanger 3, the electric expansion valve 4, and the indoor heat exchanger 5 are sequentially connected to form a refrigerant circulation path. , The indoor heat exchanger 5 is divided into a first indoor heat exchanger 5a located on the electric expansion valve 4 side and a second indoor heat exchanger 5b located on the compressor 1 side, and both heat exchangers are formed. An on-off valve 1 in which 5a and 5b are connected in series by a connecting path 9 and connected in parallel.
0 and a decompression mechanism 11 are provided in the connection path 9 to perform the cooling operation in which the indoor heat exchanger 5 functions as an evaporator while the opening / closing valve 10 is open, while the opening / closing valve 10 is used.
In the air conditioner configured to perform a dehumidifying operation in which the first indoor heat exchanger 5a functions as a condenser and the second indoor heat exchanger 5b functions as an evaporator in the valve closed state of FIG. The valve 10 includes a first passage 12 connected to the first indoor heat exchanger 5a, a second passage 13 connected to the second indoor heat exchanger 5b, and both passages 1
An internal flow passage 14 that communicates 2 and 13 is formed, a valve seat 15 is formed in the internal flow passage 14, and a valve element 16 that opens and closes the valve seat 15 is reciprocally movable to the first passage 12 side. And a shape memory spring 18 for urging the valve element 16 in the valve closing direction and a shape memory spring 18 for urging the valve element 16 in the valve opening direction. In the expanded state, the valve element 16 is moved away from the valve seat 15, while when a refrigerant having a temperature lower than that is circulated, the valve element 16 is contracted to move the valve element 16 to the valve seat 15.
A valve closing control means for stopping the air blowing to the indoor heat exchanger 5 for a predetermined time after the operation in the cooling state is started in order to close the opening / closing valve 10 by closing the valve. The feature is that 20 is provided.

The air conditioner according to a second aspect of the invention is characterized in that the valve closing control means 20 controls the opening degree of the electric expansion valve 4 to be gradually reduced within the predetermined time.

[0008]

In the air conditioner of the first aspect, when the cooling operation is started in a state in which the air blowing to the indoor heat exchanger 5 is stopped by the valve closing control means 20, the temperature of the refrigerant flowing through the indoor heat exchanger 5 is usually It will be lower than during cooling operation. Then, the shape memory spring 18 is cooled to be in a contracted state, the on-off valve 10 is closed, and the dehumidifying operation can be performed. In this case, the shape memory spring 18 is subjected to a temperature change by the liquid refrigerant having a larger heat capacity than the gas refrigerant or the gas-liquid mixed refrigerant, so that the temperature change occurs rapidly.

Further, in the air conditioner according to the second aspect, the temperature of the refrigerant can be surely and promptly lowered, so that the closing operation of the opening / closing valve 10 required when shifting to the dehumidifying operation can be surely and promptly performed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of the air conditioner of the present invention will be described in detail with reference to the drawings.

The circuit configuration is shown in FIG. 1. In the figure, 1 is a compressor, 2 is a four-way switching valve, 3 is an outdoor heat exchanger,
Reference numeral 4 denotes an electric expansion valve, and 5 denotes an indoor heat exchanger, which are connected to each other to form a refrigerant circulation path 6. Reference numeral 7 indicates an outdoor fan, and 8 indicates an indoor fan. The indoor heat exchanger 5 is divided into a first indoor heat exchanger 5a located on the electric expansion valve 4 side and a second indoor heat exchanger 5b located on the compressor 1 side. The devices 5a and 5b are connected in series by a connection path 9. An on-off valve 10 is provided in the connection path 9, and a capillary tube (pressure reducing mechanism) 11 is connected in parallel to the on-off valve 10.

As shown in FIG. 2, the on-off valve 10 includes a first passage 12 connected to the first indoor heat exchanger 5a, and a second passage 12.
A second passage 13 connected to the indoor heat exchanger 5b, and an internal passage 14 that connects the passages 12 and 13 with each other.
A valve seat 15 is formed in the internal flow passage 14. Further, in the internal flow passage 14, a valve body 16 is arranged at a position closer to the first passage 12 than the valve seat 15 so as to be capable of reciprocatingly sliding, and the valve body 16 comes into contact with and separates from the valve seat 15. By this, the on-off valve 1
The valve closing and opening operations of 0 can be performed. A bias spring 17 is arranged at a position closer to the first passage 12 than the valve body 16, and the bias spring 17 biases the valve body 16 in the valve closing direction. A shape memory spring 18 is arranged between the valve body 16 and the valve seat 15, and the shape memory spring 18 biases the valve body 16 in the valve opening direction. This shape memory spring 18 is a shape memory alloy,
It is made of a shape memory resin or the like, and is in an expanded state in a temperature range close to the temperature of the refrigerant flowing through the indoor heat exchanger 5 during the cooling operation, so that the opening / closing valve 10 is driven by the force of the shape memory spring 18. Although the valve is open as shown in FIG. 2, when the temperature is further lowered, it is in a contracted state and is closed by the force of the bias spring 17 as shown in FIG. .. 2 in FIG.
Reference numeral 0 indicates a valve closing control means for controlling the valve closing operation of the on-off valve 10, the function of which will be described later.

Next, the operating state of the air conditioner will be described. First, as shown by the solid arrow A in FIG. 1, the refrigerant from the compressor 1 is condensed in the outdoor heat exchanger 3 and evaporated in the indoor heat exchanger 5 to perform the cooling operation,
On the contrary, as shown by the broken line B, the heating operation is performed by condensing in the indoor heat exchanger 5 and evaporating in the outdoor heat exchanger 3 as in the conventional case. In the dehumidifying operation, in the cooling operation mode, the outdoor fan 7 is stopped, the electric expansion valve 4 is fully opened, and the on-off valve 10 is closed, while the first indoor heat exchanger 5a condenses the second indoor heat exchanger. 5
The indoor fan 8 is driven by causing each function of evaporation to be performed in b, and the indoor air cooled and dehumidified by the second indoor heat exchanger 5b is heated to about room temperature by the first indoor heat exchanger 5a to be indoors. Do by returning.

A point to be noted here is that the operation control by the valve closing control means 20 for closing the opening / closing valve 10 at the time of starting the dehumidifying operation is different from the conventional one. Hereinafter, that point will be described with reference to FIG. First, the operation is started in the cooling operation mode. At that time, the inverter frequency of the compressor 1 is set high (80 Hz), the electric expansion valve 4 is also set to the control opening, and the indoor fan 8 is stopped. The outdoor fan 7 is kept in operation. Thereafter, the opening degree of the electric expansion valve 4 is gradually reduced as shown in the figure. As described above, the indoor fan 8 is stopped and the opening degree of the electric expansion valve 4 is gradually decreased. As a result, the temperature of the refrigerant flowing through the opening / closing valve 10 becomes lower than the refrigerant temperature during the cooling operation, and the shape memory is maintained. The spring 18 contracts, the valve element 16 contacts the valve seat 15, and the on-off valve 10 closes. At this time, the shape memory spring 18 is cooled by the liquid refrigerant or the gas-liquid mixed refrigerant having a heat capacity larger than that of the gas refrigerant, so that the temperature thereof is rapidly lowered, so that the closing operation of the on-off valve 10 is quickly performed. Then, after a lapse of a time T sufficient to perform the valve closing operation, the electric expansion valve 4 is fully opened, the outdoor fan 7 is stopped, and then the inverter frequency of the compressor 1 is reduced to a steady operating frequency. Then, the indoor fan 8 is driven to start the dehumidifying operation. In this case, the refrigerant temperature rises with the start of the dehumidifying operation, the shape memory spring 18 of the on-off valve 10 is in an expanded state, and the valve body 16 is biased in the valve opening direction. As a result, the differential pressure of the refrigerant flow is acting, so that the valve closed state is maintained by this differential pressure.

From the above, in the above air conditioner, the transition to the dehumidifying operation can be performed more quickly than in the conventional case.
Moreover, since it does not require any special configuration, it is possible to prevent an increase in device cost. In particular, in the conventional on-off valve 54 shown in FIGS. 6 and 7, it was necessary to provide a special member called the spacer 58 in order to prevent the valve closing operation during the heating operation. Since such a member is unnecessary, the structure can be simplified.

[0016]

As described above, in the air conditioner according to the first aspect, the on-off valve is closed by using the liquid refrigerant or the gas-liquid mixed refrigerant having a larger heat capacity than the gas refrigerant. The transition to the dehumidification operation can be performed quickly. Moreover, since it is not necessary to add a special configuration for that purpose, it is possible to prevent an increase in device cost.

According to the air conditioner of the second aspect, the shift to the dehumidifying operation can be performed more rapidly and reliably.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of an air conditioner of the present invention.

FIG. 2 is a cross-sectional view showing an open state of an example of the on-off valve used in the above.

FIG. 3 is a cross-sectional view showing a closed state of the on-off valve.

FIG. 4 is a time chart diagram showing an example of operation control in the air conditioner.

FIG. 5 is a circuit diagram of a conventional air conditioner.

FIG. 6 is a cross-sectional view showing an open state of an on-off valve used in a conventional air conditioner.

FIG. 7 is a sectional view of the open / close valve in a closed state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 3 Outdoor heat exchanger 4 Electric expansion valve 5 Indoor heat exchanger 5a 1st indoor heat exchanger 5b 2nd indoor heat exchanger 6 Refrigerant circulation path 8 Indoor fan 9 Connection path 10 Open / close valve 11 Capillary tube (Decompression mechanism) ) 12 1st passage 13 2nd passage 14 Internal passage 15 Valve seat 16 Valve body 17 Bias spring 18 Shape memory spring 20 Valve closing control means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Sugimoto, 1000 Otani, Okamoto Town, Kusatsu City, Shiga Prefecture 2 Daikin Industry Co., Ltd. Shiga Factory (72) Hidehiko Kataoka 1000 Otani, Okamoto Town, Kusatsu City, Shiga Prefecture No. 2 Daikin Industry Co., Ltd. Shiga Works

Claims (2)

[Claims] 1. A compressor (1), an outdoor heat exchanger (3), an electric expansion valve (4) and an indoor heat exchanger (5) are sequentially connected to form a refrigerant circulation path, and the indoor heat exchanger is provided. (5) is a first indoor heat exchanger (5a) located on the electric expansion valve (4) side,
The second indoor heat exchanger (5b) located on the side of the compressor (1) is divided into two parts and the two heat exchangers (5a) and (5b) are connected in series by the connection path (9) and are connected in parallel. A cooling operation in which a valve (10) and a pressure reducing mechanism (11) are provided in the connection path (9) and the indoor heat exchanger (5) functions as an evaporator when the opening / closing valve (10) is open. Meanwhile, the dehumidifying operation in which the first indoor heat exchanger (5a) functions as a condenser and the second indoor heat exchanger (5b) functions as an evaporator while the on-off valve (10) is closed. In the air conditioner configured to perform the above, the on-off valve (10) includes the first indoor heat exchanger (5
An internal flow path communicating between the first passage (12) connected to a), the second passage (13) connected to the second indoor heat exchanger (5b), and both passages (12) and (13). (14), a valve seat (15) is formed in the internal flow path (14), and a valve body (16) for opening and closing the valve seat (15) is provided on the first passage (12) side. A bias spring (17) which is reciprocally arranged and biases the valve body (16) in a valve closing direction.
And a shape memory spring (18) for urging in the valve opening direction. The shape memory spring (18) is in an expanded state at the temperature of the refrigerant flowing during the cooling operation, and the valve body (16) is provided.
The valve body (1) is separated from the valve seat (15), and when a refrigerant having a temperature lower than that of the valve seat (15) circulates, the valve body (1) is contracted.
6) is configured to abut on the valve seat (15) to close the valve, and further, in order to close the on-off valve (10), the indoor heat exchanger ( An air conditioner characterized by being provided with a valve closing control means (20) for stopping the blowing of air to (5). 2. The air conditioner according to claim 1, wherein the valve closing control means (20) controls to gradually reduce the opening degree of the electric expansion valve (4) within the predetermined time.