JPH03260564A - Air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air conditioner capable of cooling operation and dry operation.

(Prior Art) A conventional air conditioner will be described with reference to FIG. 1, which is an embodiment of the present invention. In FIG. 1, 1 is a compressor, and this compressor 1 has a first
a gas pipe 5, an outdoor heat exchanger 6, a liquid pipe 9 having an electric valve 8;
The first indoor heat exchanger 10, the second indoor heat exchanger 11, and the second gas pipe I2 are connected, and the second gas pipe 12 is connected to the compressor 1.
The refrigerant circulation circuit is configured by connecting to the suction pipe 3 of the refrigerant.

Further, a capillary tube 13 and an automatic on-off valve 14 connected in parallel to each other are interposed between the first and second indoor heat exchangers 10 and 11, and a low-temperature refrigerant is supplied to the automatic on-off valve 14. Shape memory alloy spring 17 (opens during cooling and closes during dry operation when high-temperature refrigerant is supplied)
Figure 3) is provided.

Furthermore, an outdoor fan 15 that blows air to the outdoor heat exchanger 6 and an indoor fan 16 that blows air to both the indoor heat exchangers 10 and 11 are attached, respectively. In this conventional air conditioner, when the automatic on-off valve 14 is opened by low-temperature refrigerant, it forms a cooling circuit, and when the electric valve 8 is fully opened and the automatic on-off valve 14 is closed by high-temperature refrigerant, it forms a dry circuit. It is designed to be configured. In this dry circuit, the refrigerant discharged from the compressor 1 passes through the outdoor heat exchanger 6 and the electric valve 8, is condensed in the first indoor heat exchanger 10, is depressurized in the capillary tube 13, and is then transferred to the second indoor heat exchanger 10. It is evaporated in the exchanger 11 and returned 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 amount of reheat from the first indoor heat exchanger 10, and becomes dehumidified air.

In addition, as a prior art in which an automatic opening/closing valve having a shape memory alloy spring is provided between the double indoor heat exchanger l0111 and the capillary tube 13, Japanese Utility Model Application Publication No. 10359/1986 can be mentioned.

(Problem to be Solved by the Invention) However, the automatic opening/closing valve 14 automatically opens and closes when the shape memory alloy spring 17 expands and contracts due to temperature changes in the refrigerant. , there is a possibility that the opening/closing operation described above cannot be performed reliably. Therefore, prior to the dry operation, it is conceivable to perform a preliminary dry operation to promote the closing operation of the automatic on-off valve 14 to raise the refrigerant temperature. However, when performing the above-mentioned preliminary dry operation, it is preferable in terms of economy and air conditioning comfort to quickly shift to steady dry operation after the automatic on-off valve 14 closes. It is necessary to quickly and reliably transition to dry operation.

This invention was made to solve the above-mentioned conventional problems, and its purpose is to provide an air conditioner that can quickly and reliably transition from preliminary dry operation to regular dry operation. There is a particular thing.

(Means for Solving the Problems) Therefore, the air conditioner of the present invention includes, in order from the discharge side 2 of the compressor 1, a first gas pipe 5, an outdoor heat exchanger 6, and an expansion mechanism 8 whose opening degree can be freely adjusted. liquid pipe 9, first indoor heat exchanger 10,
A second indoor heat exchanger 11 and a second gas pipe 12 are connected, and 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 are connected to each other. Exchanger 10
．． A pressure reducing mechanism 13 and an automatic on-off valve 14 connected in parallel to each other are interposed between the air conditioner 11 and the automatic on-off valve 14, which opens during cooling when low-temperature refrigerant is supplied, while being opened when high-temperature refrigerant is supplied. The air conditioner is equipped with a shape memory member 17 that closes the valve during dry operation, and the dry operation command 25
is input, the preliminary operation means 34 controls the opening degree of the expansion mechanism 8 and operates the compressor 1 at high capacity.
and a steady operation means 35 that performs a steady dry operation with a lower compression capacity of the compressor 1 than during this preliminary dry operation.
and first and second temperature sensors 30.31 that detect the temperatures at at least two locations, the first and second indoor heat exchangers 10.11 and the indoor temperature, and the detected temperature difference between the two temperature sensors 30.31. a valve closing determination means 32 that outputs a valve closing determination signal 33 when the value exceeds a reference value; and a steady operation means 3 from operational control by a preliminary operation means 34 based on the valve closing determination signal 33.
The present invention is characterized in that it is provided with a mode switching means 43 for shifting to operation control according to No. 5.

(Function) In the air conditioner having the above configuration, first, during cooling, the gas refrigerant is condensed in the outdoor heat exchanger 6 and evaporated in the first and second indoor heat exchangers 10.11. At this time, since 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 dry operation, the preliminary operation means 34 controls the expansion mechanism 8 to open according to the dry operation command 25, and performs a preliminary dry operation in which the compressor 1 is operated at high capacity. During this preliminary dry operation, when the temperature difference detected by both temperature sensors 30, 31 exceeds the reference value, the valve closing determination means 32 outputs the valve closing determination signal 33. Based on this valve closing determination signal 33, the mode switching means 43 switches the compressor 1 from the preliminary dry operation by the preliminary operation means 34 to the compressor 1 operation by the steady operation means 35.
Shift to steady dry operation with reduced compression capacity. As described above, the valve closing determination means 32 determines that the automatic on-off valve 14 is closed, and then the mode switching means 43
Since this causes a transition to steady dry operation, steady dry operation can be started quickly and reliably.

Note that 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 a high-temperature gas refrigerant and condenses, while the refrigerant flows into the first indoor heat exchanger 10 and condenses.
1, the air is dehumidified in the second indoor heat exchanger 11, and then reheated in the first indoor heat exchanger 10.

(Example) Next, regarding a specific example of the air conditioner of this invention,
This will be explained in detail with reference to the drawings.

In FIG. 1 showing the 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. The 20 four-way switching valve 4 includes, in order clockwise in the figure, a first gas pipe 5, an outdoor heat exchanger 6, a liquid pipe 9 having an electric valve 8, a first indoor heat exchanger 10, and a second The indoor heat exchanger 11 and the second gas pipe 12 are 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. It constitutes a refrigerant circulation circuit. Note that the electric valve 8 functions as an expansion mechanism, and a capillary tube may also be used. A capillary tube (pressure reducing mechanism) 13 and an automatic on-off valve 14 are interposed between the first and second indoor heat exchangers 10 and 11, which are connected in parallel to each other. This automatic opening/closing valve 14
is provided with a shape memory alloy spring (shape memory member) 17 which opens during cooling when low temperature refrigerant is supplied and closes during dry operation when high temperature refrigerant is supplied, as will be described in detail later. . An 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 are also attached. The liquid pipe 9
Bypass piping 20 is connected before and after the electric valve 8 so as to bypass the electric valve 8. This bypass piping 20 includes a regenerative heat exchanger 2 arranged around the compressor 1.
2 is interposed. This heat storage heat exchanger 22 is for extracting the amount of heat for defrosting the outdoor heat exchanger 6. An on-off valve 21 that allows refrigerant to flow in both directions is interposed in a portion of the bypass pipe 20 on the outdoor heat exchanger 6 side. Furthermore, first and second temperature sensors 30.31 are attached to both indoor heat exchangers 10.11, respectively. The installation locations of both temperature sensors 30 and 31 are as follows:
Both indoor heat exchangers 10.11 and any two of the three indoor locations can be selected.

The structure of the automatic on-off valve 14 will be explained with reference to FIG. 3(a).

This automatic opening/closing valve 14 includes a valve body 50, a spacer 51, a pin 52, a bias spring 53, and the shape memory alloy spring 1.
7. In addition, the main body 55 of the automatic on-off valve 14 includes:
A stepped stopper 56 is formed to position the spacer 51. The shape memory alloy spring 17 is
It shortens during cooling when low-temperature refrigerant is supplied, and expands against the spring force of the bias spring 53 during dry operation when high-temperature refrigerant is supplied.

On the other hand, the control device 40 having the operation control function of the air conditioner includes, as shown in FIG. A preliminary operation means 34, a steady operation means 35, a mode switching means 43, and a delay timer 44 are provided, respectively. Note that a dry operation command 25, a cooling operation command 45, and a heating operation command 46 are each inputted to the control device 40 from the outside. The preliminary operation means 34
The steady operation means 35 has a function of performing preliminary dry operation and steady dry operation, which will be described in detail later.

Further, the valve closing determination means 32 includes both the temperature sensors 30 and 31.
It has a function of outputting a valve closing determination signal 33 when the detected temperature difference exceeds a reference value (for example, 20° C.). 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 manually input, and It has a function of controlling the switching state to switch between cooling operation and heating operation.

To explain the valve closure determination function of the valve closure determination means 32, as shown in FIG. 5, during dry operation, the first indoor heat exchanger 10 becomes high temperature due to condensation of the refrigerant, and becomes colder due to evaporation of the refrigerant. and the sixth
As shown in the graph of the figure, after the automatic on-off valve 14 closes at time T, the temperature characteristics 65 of the first indoor heat exchanger 10,
Temperature characteristics 66 of automatic opening/closing valve 14, second indoor heat exchanger 11
Since the temperature characteristics 67 of the indoor heat exchangers 10 and 11 change respectively, when the temperature difference between the indoor heat exchangers 10 and 11 exceeds 20°C as described above, it can be determined that the automatic opening/closing valve 14 is closed. . In addition, since the temperature characteristics 65.67 of both indoor heat exchangers 1O111 both show relatively large temperature changes with respect to the room temperature level 68, the first and second temperature sensors 30.31 Or second indoor heat exchanger 10
, 11, it is also possible to determine the valve closed state by detecting the temperature characteristics 65, 67 of .

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 a preliminary dry operation. In this operation mode, as shown in step S1 in FIG.
The fan control means 26 operates the outdoor fan 1 at a high frequency.
5. The indoor fan 16 is stopped, and the valve opening/closing means 27 fully opens the electric valve 8 and opens the opening/closing valve 21, thereby preventing the refrigerant from being condensed in the outdoor heat exchanger 6. ing. Then, in the next step S2, when the valve closing determination signal 33 is output from the valve closing determining means 33,
Step S3 assumes that the automatic on-off valve 14 is fully closed.
On the other hand, if the automatic on-off valve 14 is not fully closed, the process returns to step S1 to continue the preliminary dry operation.

In step S3, the mode switching means 43 switches from operation control by the preliminary operation means 34 to steady dry operation using the steady operation means 35. In this steady dry operation, the fan control means 26 operates or stops the outdoor fan 15 and also operates the indoor fan 16, the steady operation means 35 operates the compressor 1 at a lower frequency than the above, and the valve opening/closing means 27 The electric valve 8 is fully opened, and the on-off valve 21 is opened.

The delay timer 44 delays the switching timing of the four-way switching valve 4 when the compressor 1 is stopped by a predetermined delay time T seconds from the time when the compressor 1 is stopped. It has a function of suppressing the differential pressure as low as possible (for example, to 6 kg/d or less). That is, in the refrigerant circulation circuit shown in FIG. 1, since the valve element 50 of the automatic on-off valve 14 is configured to operate based on the differential pressure of the refrigerant, the valve element 50 operates at high speed when the operation is stopped. The delay time T is set in such a way that it is possible to prevent the occurrence of a loud switching noise that would cause problems in indoor units of air conditioners. In other words, as shown in FIG. 4, the acceleration when the valve body 50 moves changes as shown in characteristic 60 according to the pressure difference before and after the automatic opening/closing valve 14, so the pressure difference of characteristic 60 is approximately 6 kg. By suppressing the switching noise to a range of /all or less, the valve body 50 is operated relatively slowly, and care is taken to prevent the switching noise from exceeding level 61, which causes a problem for human hearing.

Next, the operating state of the above embodiment will be explained. First, during cooling, the four-way switching valves are maintained in the state shown in FIG. 1 to circulate the refrigerant clockwise in the diagram. At this time, the on-off valve 21 is kept closed. During this cooling, the gas refrigerant is condensed in the outdoor heat exchanger 6 and evaporated in the first and second indoor heat exchangers 10 and 11.

At this time, the automatic opening/closing valve 14 is supplied with low-temperature refrigerant from the first indoor heat exchanger 10 toward the second indoor heat exchanger 11, so that the shape memory alloy spring is activated as shown in FIG. 3(a). 17 is shortened, and the automatic switching 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 and opens the automatic switching valve 14. Pass through 14.

Next, during dry operation when the dry operation command 25 is manually inputted 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. 2 above. At this time, the fan control means 26 stops both the outdoor and indoor fans 15 and 16, and the valve opening/closing means 27 opens the opening/closing valve 21 and fully opens the electric valve 8. Therefore, the refrigerant does not condense in the outdoor heat exchanger 11, and the high-temperature gas refrigerant flows into the first indoor heat exchanger 10, causing the automatic opening/closing valve 14 to flow into the first indoor heat exchanger 10.
reach. The shape memory alloy spring 17 of the automatic on-off valve 14 is expanded by this high-temperature gas refrigerant, and the spacer 51 moves until it comes into contact with the stopper 56 as shown in FIG. The valve closes by moving to the center right.

In the above embodiment, in such a case, the on-off valve 21 is open, so the refrigerant also flows through the bypass pipe 20, and the refrigerant passage before and after the electric valve 8 is connected to the bypass pipe 20. Since the temperature increases by that amount, the high-temperature gas refrigerant flows more easily.

When the refrigerant flows more easily, the pressure loss before and after the electric valve 8 is reduced, and the temperature drop of the refrigerant due to 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 closing operation of the automatic on-off valve 14 is promoted, and the automatic on-off valve 14 is closed for a short time. The valve will close more reliably.

Then, in step S2 of FIG. 2, the valve closure determining means 32 determines whether the automatic on-off valve 14 is closed or not. When the valve closing determination means 32 outputs the valve closing determination signal 33, the mode switching means 43 changes from the operation control by the preliminary operation means 34 to the steady operation control by the steady operation means 35 in step S3.
The operation mode is switched to steady dry operation, and dry operation is performed under the operation control in 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. Valve 21 is closed. In this state, the refrigerant flows through the automatic opening/closing valve 14 from the second indoor heat exchanger 11 side toward the first indoor heat exchanger 10, so that the shape memory alloy spring 17 is activated as shown in FIG. 3(C). Even if it is extended, the flow of refrigerant will cause the valve body 5 to
0 moves in the valve opening direction and the valve is opened. Incidentally, the defrost operation during this heating operation is performed by closing the electric valve 8 and opening the on-off valve 21 to utilize the heat stored in the heat storage heat exchanger 22.

Although specific embodiments of the air conditioner of this invention have been described above, this invention is not limited to the above embodiments, and can be implemented with various changes within the scope of this invention. . For example, in the embodiment described above, the shape memory alloy spring 17 is used for the automatic opening/closing valve 14, but the shape memory alloy spring 17 is not limited thereto, and other shape memory resins or the like may also be used.

Further, when the present invention is applicable to an air conditioner dedicated to cooling or dry operation, the four-way switching valve 4 is not necessary, and the pressure reducing mechanism is not limited to the capillary tube 13, but an electric valve may also be used.

(Effect of the invention) As described above, in the air conditioner of this invention, the first
, when the temperature difference detected by the second temperature sensor exceeds a reference value, the valve closing determination means outputs a valve closing determination signal, so that it can be determined that the automatic opening/closing valve is closed. , it is possible to quickly and reliably shift the operating state of the air conditioner from preliminary dry operation to regular dry operation based on the valve closing determination signal, thereby improving the economic efficiency of dry operation and increasing air conditioning comfort. This makes it possible to improve sexual performance.

[Brief explanation 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 flowchart showing a signal processing process in a control device of an embodiment, and Fig. 3 is a vertical cross-sectional view showing an automatic on-off 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 the double-indoor heat exchanger, and FIG. 6 is a graph showing changes in temperature of various parts with respect to time. DESCRIPTION OF SYMBOLS 1...Compressor, 2...Discharge piping, 3...Suction piping, 5...First gas pipe, 6...Outdoor heat exchanger, 8...
・Electric valve (expansion mechanism), 9...liquid pipe, 10...first
Indoor heat exchanger, 11...Second indoor heat exchanger, 12...
・Second gas pipe, 13... Capillary tube (fI
ji pressure mechanism), 14... Automatic opening/closing 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. Figure 2 Figure 4 Differential pressure (kg/cm”) Figure 5 Figure 6

Claims (1)

[Claims] 1. In order from the discharge side (2) of the compressor (1), a first gas pipe (5), an outdoor heat exchanger (6), and a liquid pipe (9) having an expansion mechanism (8) whose opening degree can be freely adjusted; 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 connected to the suction side (3) of the compressor (1) to form a refrigerant circulation circuit. and the above first
, a pressure reducing mechanism (13) and an automatic on-off valve (14) connected in parallel to each other are interposed between the second indoor heat exchangers (10 and 11), and the automatic on-off valve (14) is equipped with a low-temperature An air conditioner equipped with a shape memory member (17) that opens the valve during cooling when refrigerant is supplied and closes during dry operation when high-temperature refrigerant is supplied, and a dry operation command (25) is input. When the expansion mechanism (8) is opened, the preliminary operating means (34) controls the opening degree of the expansion mechanism (8) and operates the compressor (1) at a high capacity.
steady operation means (35) for performing steady dry operation with reduced compression capacity of the first and second indoor heat exchangers (
10) The first and second temperature sensors (30) and (31) detect temperatures at at least two locations: (11) and the room temperature, and the detected temperature difference between these two temperature sensors (30) and (31) exceeds the reference value. A valve closing determination means (32) outputs a valve closing determination signal (33) when the value is exceeded, and a steady operation means (35) is operated from operation control by a preliminary operation means (34) based on the valve closing determination signal (33). Mode switching means (
43) An air conditioner characterized by comprising: