JPH0833263B2 - Air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air conditioner capable of performing a cooling operation and a dry operation.

(Prior Art) A conventional air conditioner will be described with reference to FIG. 1, which is an embodiment drawing of the present invention. In FIG. 1, reference numeral 1 denotes a compressor. In the compressor 1, a first gas pipe 5, an outdoor heat exchanger 6, a liquid pipe 9 having a motor-operated valve 8, and a first pipe 1 are arranged in this order from a discharge pipe 2 thereof. The indoor heat exchanger 10, the second indoor heat exchanger 11, and the second gas pipe 12 are connected, and the second gas pipe 12 is connected to the suction pipe 3 of the compressor 1 to form a cooling circulation circuit. A capillary tube 13 and an automatic opening / closing valve 14 connected in parallel are provided between the first and second indoor heat exchangers 10 and 11, and a low temperature refrigerant is supplied to the automatic opening / closing valve 14. A shape memory alloy spring 17 (Fig. 3) is provided which opens during cooling and closes during dry operation in which high temperature refrigerant is supplied. Furthermore, the outdoor fan 15 that blows air to the outdoor heat exchanger 6
And an indoor fan 16 that blows air to both indoor heat exchangers 10 and 11, respectively. In this conventional air conditioner, when the automatic opening / closing valve 14 is opened by the low temperature refrigerant,
A cooling circuit is configured, and the motor-operated valve 8 is fully opened to automatically open / close the valve 14.
When the valve is closed by the high temperature refrigerant, it forms a dry circuit. In this dry circuit, the refrigerant discharged from the compressor 1 passes through the outdoor heat exchanger 6 and the motor-operated valve 8, is condensed in the first indoor heat exchanger 10, is decompressed in the capillary tube 13, and then is discharged in the second indoor heat. It evaporates in the exchanger 11 and returns to the compressor 1. After the indoor air is dehumidified by the second indoor heat exchanger 11, it is heated to about room temperature by the reheat amount of the first indoor heat exchanger 10 to become dehumidified air.

Both indoor heat exchangers 10 and 11 and capillary tube 13
As a prior art in which an automatic opening / closing valve having a shape memory alloy spring is provided between and, Japanese Utility Model Publication No. 63-10359 can be cited.

(Problems to be solved by the invention) However, since the automatic on-off valve 14 automatically opens and closes by the expansion and contraction of the shape memory alloy spring 17 due to the temperature change of the refrigerant, when the temperature change of the refrigerant is small, ,
There is a possibility that the above-mentioned opening / closing operation cannot be performed reliably. Therefore, prior to the dry operation, it is conceivable to perform the preliminary dry operation for promoting the valve closing operation of the automatic opening / closing valve 14 to raise the refrigerant temperature. However, in the case of performing the above preliminary dry operation, it is preferable from the viewpoint of economical efficiency and air-conditioning comfort that the automatic open / close valve 14 is switched to a steady dry operation after the valve is closed. There is a need to quickly and surely shift to a standard dry operation.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide an air conditioner that can perform a transition from a preliminary dry operation to a steady dry operation quickly and reliably. Especially.

(Means for Solving the Problem) Therefore, the air conditioner of the present invention is provided with the discharge side 2 of the compressor 1.
In order from the first gas pipe 5, the outdoor heat exchanger 6, the liquid pipe 9 having the expansion mechanism 8 whose opening can be adjusted, the first indoor heat exchanger 10,
While connecting the second indoor heat exchanger 11 and the second gas pipe 12,
The second gas pipe 12 is connected to the suction side 3 of the compressor 1 to form a refrigerant circulation circuit, and the first and second indoor heat exchangers 10 and 11 are automatically connected to the decompression mechanism 13 connected in parallel with each other. The automatic opening / closing valve 14 is provided, and the automatic opening / closing valve 14 is provided with a shape memory member 17 that performs a valve opening operation during cooling when a low temperature refrigerant is supplied and a valve closing operation during a dry operation in which a high temperature refrigerant is supplied. In the air conditioner, the expansion mechanism 8 is controlled to open when the dry operation command 25 is input, and the compressor 1
The preliminary operation means 34 for performing the high-capacity operation, the steady operation means 35 for performing the steady dry operation in which the compression capacity of the compressor 1 is lower than that during the preliminary dry operation, and the first and second indoor heat The first and second temperature sensors 30 and 31 for detecting the temperature of at least two places between the exchangers 10 and 11 and the room, and the valve closing when the temperature difference between the temperature sensors 30 and 31 exceeds a reference value. A valve closing determination means 32 for outputting a determination signal 33, and a mode switching means for shifting the operation control by the preliminary operation means 34 to the operation control by the steady operation means 35 based on the valve closing determination signal 33.
It is characterized by having 43 and.

(Operation) In the air conditioner configured as described above, first, during cooling,
While the gas refrigerant is condensed in the outdoor heat exchanger 6, the first,
It is evaporated in the second indoor heat exchangers 10 and 11. At this time, since a low-temperature refrigerant flows through the automatic switching valve 14, the automatic switching valve 14 automatically opens, and the refrigerant passes through the automatic switching valve 14 without passing through the pressure reducing mechanism 13.

On the other hand, during the dry operation, the preliminary operation means 34 controls the opening degree of the expansion mechanism 8 by the dry operation command 25, and
Preliminary dry operation is performed to operate the compressor 1 with high capacity. In this preliminary dry operation, when the temperature difference between the temperature sensors 30 and 31 exceeds the reference value, the valve closing determination means 32 outputs the valve closing determination signal.
Outputs 33. Based on the valve closing determination signal 33, the mode switching means 43 shifts from the preliminary dry operation by the preliminary operation means 34 to the steady dry operation in which the compression capacity of the compressor 1 by the steady operation means 35 is reduced. As described above, the valve closing determination means 32 determines that the automatic opening / closing valve 14 is closed, and then the mode switching means 43 shifts to the steady dry operation, so that the steady dry operation is quick and reliable. Will be started.

During the dry operation, the refrigerant does not condense in the outdoor heat exchanger 11, and the refrigerant flows into the first indoor heat exchanger 10 as it is as a high-temperature gas refrigerant and condenses, while it evaporates in the second indoor heat exchanger 11. First, after dehumidifying the air in the second indoor heat exchanger 11,
Reheat in the indoor heat exchanger 10.

(Example) Next, a specific example of the air conditioner of the present invention will be described in detail with reference to the drawings.

In FIG. 1 showing a case where the present invention is applied to an air conditioner capable of cooling, heating, and dry operation, 1 is a compressor, and a discharge pipe 2 of this compressor 1 is connected to a four-way switching valve 4. However, the four-way switching valve 4 has a first
A gas pipe 5, an outdoor heat exchanger 6, a liquid pipe 9 having an electrically operated valve 8,
First indoor heat exchanger 10, second indoor heat exchanger 11, second gas pipe
12 is connected and the second gas pipe 12 is connected to the four-way switching valve 4
And the suction pipe 3 of the compressor 1 is connected to the four-way switching valve 4 to form a refrigerant circulation circuit. The electric valve 8 functions as an expansion mechanism, and a capillary tube can be used. Between the first and second indoor heat exchangers 10 and 11, a capillary tube (pressure reducing mechanism) 13 and an automatic opening / closing valve connected in parallel with each other are provided.
14 and. A shape memory alloy spring (shape memory member) 17 that opens in the automatic open / close valve 14 during cooling when low-temperature refrigerant is supplied and closes during dry operation in which high-temperature refrigerant is supplied will be described in detail later. Is provided. In addition, an outdoor fan 15 that blows air to the outdoor heat exchanger 6,
An indoor fan 16 that blows air to both indoor heat exchangers 10 and 11 is attached. Before and after the motor-operated valve 8 of the liquid feeling 9,
A bypass pipe 20 is connected so as to bypass the electric valve 8. In the bypass pipe 20, the inside of the heat storage heat exchanger 22 arranged around the compressor 1 is provided. The heat storage heat exchanger 22 is for extracting the amount of heat for defrosting the outdoor heat exchanger 6. An opening / closing valve 21 through which a refrigerant can flow in both directions is provided in a portion of the bypass pipe 20 on the outdoor heat exchanger 6 side. In addition, both indoor heat exchangers 1
First and second temperature sensors 30 and 31 are attached to 0 and 11, respectively. The two temperature sensors 30 and 31 can be installed at any two locations of the both indoor heat exchangers 10 and 11 and the three locations inside the room.

The structure of the automatic opening / closing valve 14 will be described with reference to FIG.
The automatic opening / closing valve 14 has a valve body 50, a spacer 51, a pin 52, a bias spring 53, and the shape memory alloy spring 17 described above. Further, a stepped stopper 56 for positioning the spacer 51 is formed on the main body 55 of the automatic opening / closing valve 14. The shape memory alloy spring 17 is shortened during cooling when a low temperature refrigerant is supplied, and stretches against the spring force of the bias spring 53 during a dry operation when a high temperature refrigerant is supplied.

On the other hand, in the control device 40 having the operation control function of the air conditioner, as shown in FIG. 1, the fan control means (fan stop means) 26, the valve opening / closing means (valve opening means) 27, the valve closing determination means 3
2, preliminary operation means 34, steady operation means 35, mode switching means 4
3 and a delay timer 44 are provided respectively. The dry operation command 25, the cooling operation command 45, and the heating operation command 46 are input to the controller 40 from the outside. The preliminary operation means 34 and the steady operation means 35 are
It has a function of performing a preliminary dry operation and a steady dry operation which will be described in detail later. Further, the valve closing determination means 32 determines that the temperature difference between the temperature sensors 30 and 31 is a reference value (for example, 20
(C)), the valve closing determination signal 33 is output. The mode switching means 43 has a function of shifting from the preliminary dry operation by the preliminary operation means 34 to the steady dry operation by the steady operation means 35 when the valve closing determination signal 33 is input, and the function of the four-way switching valve 4 described above. It has a function of controlling the switching state to switch between cooling operation and heating operation.

The valve closing determination function of the valve closing determination means 32 will be described. As shown in FIG. 5, during the dry operation, the first indoor heat exchanger 10 becomes high temperature due to the condensation of the refrigerant, and the second indoor heat exchanger 11 Is cooled by evaporation of the refrigerant. Then, as shown in the graph of FIG. 6, after the automatic opening / closing valve 14 is closed at time T ₁ , the temperature characteristic 65 of the first indoor heat exchanger 10 and the automatic opening / closing valve 14
Since the temperature characteristic 66 of the indoor heat exchanger 11 and the temperature characteristic 67 of the second indoor heat exchanger 11 change respectively, when the temperature difference between the indoor heat exchangers 10 and 11 exceeds 20 ° C as described above, the automatic opening / closing valve 14 It can be determined that the valve is closed. Since the temperature characteristics 65 and 67 of both indoor heat exchangers 10 and 11 show a relatively large temperature change with respect to the room temperature level 68, the first and second temperature sensors 30 and 31 have room temperature, It is also possible to determine the valve closed state by detecting the temperature characteristics 65 and 67 of either the first or second indoor heat exchanger 10 or 11.

When the dry operation command 25 is input, the preliminary operation means 34, the fan control means 26, and the valve opening / closing means 27 perform the preliminary dry operation. In this operation mode, the steps in Fig. 2
As shown in S1, the preliminary operation means 34 operates the compressor 1 at a high frequency, and the fan control means 26 causes the outdoor fan 15 and the indoor fan to operate.
16 is stopped, the valve opening / closing means 27 fully opens the electric valve 8, and the opening / closing valve 21 is opened, thereby preventing the refrigerant from being condensed in the outdoor heat exchanger 6. Then, in the next step S2, the valve closing determination signal from the valve closing determination means 33.
When 33 is output, it is determined that the automatic opening / closing valve 14 is in the fully closed state, and the process proceeds to step S3. On the other hand, when the automatic opening / closing valve 14 is not fully closed, the process returns to step S1 to continue the preliminary dry operation. In step S3 above, the mode switching means
43 is the operation control from the preliminary operation means 34 to the steady operation means
Switch to steady dry operation by 35. In this steady dry operation, the fan control means 26 controls the operation or stop of the outdoor fan 15, the indoor fan 16 is operated, the steady operation means 35 operates the compressor 1 at a lower frequency than the above, and the valve opening / closing means 27. Fully open the motor-operated valve 8 and open the on-off valve 21.

The delay timer 44 delays the switching timing of the four-way switching valve 4 when the operation of the compressor 1 is stopped by delaying a predetermined delay time T seconds from the time when the compressor 1 is stopped, so that the automatic switching valve 14 is provided before and after the switching valve. Make the differential pressure as low as possible (eg
It has a function to suppress it (less than 6 kg / cm ² ). That is, in the refrigerant circulation circuit of FIG.
Since the valve body 50 is configured to operate by the differential pressure of the refrigerant, the valve body 50 operates at a high speed when the operation is stopped, and a large switching noise causing a problem in the indoor unit of the air conditioner is generated. The delay time T so that it can be prevented from occurring.
Is set. That is, as shown in FIG. 4, the acceleration when the valve body 50 moves changes like a characteristic 60 according to the differential pressure across the automatic opening / closing valve 14, so the characteristic 60
By controlling the differential pressure of about 6 kg / cm ² or less, the valve body 50 is operated relatively slowly so that the switching sound does not exceed the problematic level 61 from human hearing. It is considered.

Next, the operating state of the above embodiment will be described. First, during cooling, the four-way switching valve 4 is maintained in the state shown in FIG. 1 to circulate the refrigerant clockwise in the figure. At this time, the open / close valve 21 is closed. During this cooling, the outdoor heat exchanger 6 condenses the gas refrigerant and the first and second indoor heat exchangers 10 and 11 evaporate it. At this time, since the low-temperature refrigerant is supplied to the automatic opening / closing valve 14 from the first indoor heat exchanger 10 toward the second indoor heat exchanger 11, as shown in FIG. 17, the automatic opening / closing valve 14 is opened by moving the valve body 50 to the left in the figure by the bias spring 53 via the spacer 51, and the refrigerant does not pass through the capillary tube 13,
Passes through the automatic switching valve 14.

Next, during the dry operation in which the dry operation command 25 is input to the control device 40, the mode switching means 43 first starts the operation control of the preliminary dry operation shown in step S1 of FIG.
At this time, the fan control means 26 controls both the outdoor and indoor fans 15,
16 is stopped, and the valve opening / closing means 27 opens the opening / closing valve 21 and fully opens the electric valve 8. Therefore, the refrigerant is not condensed in the outdoor heat exchanger 11, and the high temperature gas refrigerant flows into the first indoor heat exchanger 10 and reaches the automatic opening / closing valve 14. With this high temperature gas refrigerant, the shape memory alloy spring 17 of the automatic opening / closing valve 14 expands,
As shown in FIG. 3B, the spacer 51 moves until it comes into contact with the stopper 56, and the valve body 50 moves rightward in the figure due to the differential pressure, thereby closing the valve.

In the above embodiment, since the on-off valve 21 is opened in such a case, the refrigerant also flows through the bypass pipe 20, and the refrigerant passage before and after the motor-operated valve 8 has the bypass pipe 20. The hot gas refrigerant easily flows because of the increase in the amount. When the refrigerant easily flows, the pressure loss before and after the motor-operated valve 8 is reduced, and the temperature decrease of the refrigerant due to the condensation in the outdoor heat exchanger 11 is reduced. Moreover, since the fan control means 26 stops both the outdoor and indoor fans 15 and 16 to further reduce the temperature drop of the refrigerant, the automatic opening / closing valve
The valve closing operation of 14 is promoted, and the automatic opening / closing valve 14 will be closed more reliably in a short time.

Then, in step S2 of FIG. 2, the valve closing determination means 32 determines whether or not the automatic opening / closing valve 14 is closed.
When the valve closing determination means 32 outputs the valve closing determination signal 33, the mode switching means 43 causes the preliminary operation means in step S3.
The operation mode is switched from the operation control by 34 to the steady dry operation by the steady operation means 35, and the dry operation is performed by the operation control of step S3 described above.

During the heating operation, the mode switching means 43 switches the four-way switching valve 4 in the opposite direction to the state shown in FIG. 1 to allow the refrigerant to flow in the counterclockwise direction and throttle the opening degree of the motor-operated valve 8 to open / close it. Close valve 21. In this state, the automatic opening / closing valve 14 has a second
Since the refrigerant flows from the indoor heat exchanger 11 side toward the first indoor heat exchanger 10, as shown in FIG. 3C, even if the shape memory alloy spring 17 is expanded, the flow of the refrigerant causes the valve body 50 to flow. Moves in the valve opening direction and opens. By the way, the defrost operation during the heating operation is performed by closing the motor-operated valve 8 and opening the on-off valve 21, and utilizing the heat stored in the heat storage heat exchanger 22.

The specific embodiments of the air conditioner of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be carried out within the scope of the present invention. . For example, in the above-mentioned embodiment, the shape memory alloy spring 17 is used for the automatic opening / closing valve 14, but not limited to this, another shape memory resin or the like may be used. Further, when applied to an air conditioner dedicated to cooling and dry operation, the four-way switching valve 4 is not necessary, and the pressure reducing mechanism is not limited to the capillary tube 13 and an electrically operated valve can be used.

(Effect of the Invention) As described above, in the air conditioner of the present invention, when the temperature difference between the first and second temperature sensors exceeds the reference value, the valve closing determination means outputs the valve closing determination signal. By doing so, it is possible to determine that the automatic opening / closing valve has closed, so that the operating state of the air conditioner can be changed quickly from the preliminary dry operation to the steady dry operation based on the valve closing determination signal. As a result, it is possible to reliably shift the air conditioner, which makes it possible to improve the economical efficiency of dry operation and the comfort of air conditioning.

[Brief description of drawings]

FIG. 1 is a piping system diagram showing a refrigerant circuit according to an embodiment of the present invention, FIG. 2 is a flow chart diagram showing a signal processing process in a control device of the embodiment, and FIG. 3 is a longitudinal sectional view showing an automatic opening / closing valve. FIG. 4 is a graph showing changes in differential pressure and acceleration of the valve body, FIG. 5 is a schematic diagram of the structure of both indoor heat exchangers, and FIG. 6 is a graph showing changes in temperature of each part with respect to time. 1 ... Compressor, 2 ... Discharge pipe, 3 ... Suction pipe, 5 ...
… First gas pipe, 6 …… Outdoor heat exchanger, 8 ・ ・ ・ Motor-operated valve (expansion mechanism), 9 …… Liquid pipe, 10 …… First indoor heat exchanger, 11 ……
2nd indoor heat exchanger, 12 …… Second gas pipe, 13 …… Capillary tube (pressure reducing mechanism), 14 …… Automatic open / close valve, 17 ……
Shape memory alloy spring (shape memory member), 25 ... Dry operation command, 30 ... First temperature sensor, 31 ... Second temperature sensor,
32 ... valve closing determination means, 33 ... valve closing determination signal, 34 ... preliminary operation means, 35 ... steady operation means, 43 ... mode switching means.

Claims (1)

[Claims] 1. A liquid pipe having a first gas pipe (5), an outdoor heat exchanger (6), and an expansion mechanism (8) whose opening can be adjusted in order from the discharge side (2) of the compressor (1). 9), the first indoor heat exchanger (10), the second indoor heat exchanger (11) and the second gas pipe (12) are connected, and the second gas pipe (12) is sucked into the compressor (1). The refrigerant circulation circuit is connected to the side (3), and the pressure reducing mechanism (13) and the automatic opening / closing valve (14) are connected in parallel between the first and second indoor heat exchangers (10) and (11). ), And a shape memory member (17) that opens during automatic cooling when low-temperature refrigerant is supplied to the automatic open-close valve (14) and closes during dry operation when high-temperature refrigerant is supplied. An air conditioner provided with a control unit for controlling the opening of the expansion mechanism (8) and performing a high capacity operation of the compressor (1) when a dry operation command (25) is input. Pre-driving means (34)
A steady operation means (35) for performing a steady dry operation in which the compression capacity of the compressor (1) is lower than that in the preliminary dry operation, and the first and second indoor heat exchangers (10) ( 11) and the first and second detecting the temperature of at least two places inside the room
Temperature sensor (30) (31) and both temperature sensors (30)
A valve closing determination means (32) that outputs a valve closing determination signal (33) when the temperature difference detected by (31) exceeds a reference value, and a preliminary operation means (34) based on the valve closing determination signal (33). ), And a mode switching means (43) for shifting from the operation control by (1) to the operation control by the steady operation means (35).