JP3099574B2 - Air conditioner pressure equalizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure equalizing device for an air conditioner in which a discharged refrigerant gas is sealed in a pipeline for improving performance at the time of starting.

[0002]

2. Description of the Related Art Conventionally, as a pressure equalizing device for an air conditioner of this type, for example, one described in Japanese Patent Application Laid-Open No. 63-238365 is known. Although the specific configuration of the air conditioner and the pressure equalizer is different from that of the present invention, the basic configuration and operation will be described with reference to FIG. 4 similar to the present invention (FIG. 1). Then it looks like this: That is, the air conditioner is
An outdoor heat exchanger 13 having a compressor 11, a four-way switching valve 12, a fan 14, an electric expansion valve 15, and an indoor heat exchanger 16a.
To 16d are sequentially connected by pipes 17a to 17f to form a heat pump type refrigeration circuit, and a first open / close valve 18 having a check function for preventing a flow toward the compressor 11 is provided in the discharge pipe 17a. The discharge pipe line 1 on the compressor side from the first on-off valve 18
7 a and the suction line 17 f are connected by a pressure equalizing line 19 provided with a second on-off valve 20. The indoor heat exchanger 16a ~
16d is a liquid shut-off valve 21, a header 22, each indoor expansion valve 2
3a to 23d, a header 24, and a gas shutoff valve 25, are connected in parallel between the pipes 17d and 17e and arranged in a plurality of chambers. In addition, a liquid receiver 26 having a filter 27 is provided in the pipe 17d, and the liquid receiver 26 and the pipe 17f are connected by a pipe 28 provided with a capillary tube 29. On the other hand, the compressor 11 detects that an overcurrent of a predetermined value or more has flowed through the motor, stops the compressor 11, and controls the expansion valve 15, the indoor expansion valves 23 a to 23 d, and the second on-off valve 20. Is provided with a control unit 30 also serving as a protection device for controlling the opening degree.

During the heating operation, the control unit 30 opens the first on-off valve 18, closes the second on-off valve 20, and sets the four-way switching valve 12
Is switched to the passage shown by the broken line, and the gas refrigerant discharged from the compressor 11 is supplied to the indoor heat exchanger 1 as shown by the solid arrow in FIG.
The mixture is condensed in 6a to 16d and circulated so as to evaporate in the outdoor heat exchanger 13, thereby heating the room. When the operation switch is turned off and the compressor 11 stops, the expansion valve 1 is immediately stopped.
5 and each of the indoor expansion valves 16a to 16d are fully closed, and the first on-off valve 1
8, the high-temperature, high-pressure discharge refrigerant gas is sealed in a part of the pipe 17a and the pipes 17e, 17d, so that the heating capacity rises when the compressor is restarted. I try to improve. On the other hand, during the cooling operation, the second on-off valve 20 is closed and the first on-off valve 18 is opened, but the check function thereof is deactivated, the four-way switching valve 12 is switched to the path shown by the solid line, and the discharged refrigerant gas is discharged. As shown by the dashed arrow, the indoor heat exchanger 13 is condensed and circulated so as to evaporate in the indoor heat exchangers 16a to 16d to cool the room.

The control unit 30 detects an overcurrent as a protection device and stops the compressor 11 in order to prevent the coil from burning and the power transistor from being damaged. 15 and each indoor expansion valve 16a-16d
, And the second on-off valve 20 of the pressure equalizing line 19 is opened for a predetermined time to make the high pressure discharge line 17a communicate with the low pressure suction line 17f in order to facilitate the restart of the compressor.
Equalize pressure. Then, when an overcurrent flows again through the compressor 11 at the time of restart, an alarm is displayed.

[0005]

However, in the conventional pressure equalizing device, when the overcurrent of the compressor 11 is detected and the motor is stopped, only the second on-off valve 20 of the pressure equalizing line 19 is set to a predetermined value. Since the valve is opened only for equalizing the pressure between the discharge line 17a and the suction line 17f of the compressor 11, the first on-off valve 18 having a check function and the indoor expansion valves 23a to 23d are provided.
And the high-temperature, high-pressure discharge refrigerant gas sealed between these and the expansion valve 15 are supplied to the indoor heat exchangers 16a to 16d.
The pressure is only slightly reduced by natural cooling. Therefore, the refrigerant gas discharged from the compressor 11 by the restart is the first gas.
When the check valve of the on-off valve 18 is to be opened, an excessive load is applied to the compressor 11 due to the high-pressure refrigerant gas sealed on the downstream side, an overcurrent flows to the motor, and the protection device operates to activate the protection device again. There is a high possibility that the compressor 11 is stopped. Further, the above-mentioned conventional pressure equalizing apparatus has a disadvantage that even if such a re-stop occurs, only a warning is displayed and the re-stop cannot be eliminated positively.

[0006] Therefore, an object of the present invention is to provide a system in which, when a compressor is stopped by a protection device that detects an overcurrent, the inside of a pipe from an open / close valve of a discharge pipe to an expansion valve via an indoor heat exchanger is also equalized. It is an object of the present invention to provide a pressure equalizing device for an air conditioner which can eliminate a re-stop at the time of starting the compressor by pressurizing and can improve the rise of heating capacity at the time of starting as a whole.

[0007]

In order to achieve the above object, an equalizer for an air conditioner according to the present invention, as shown in FIGS. 1 and 3, has a compressor 11 and an outdoor unit which can operate as an evaporator. The heat exchanger 13, the expansion valve 15, and the indoor heat exchangers 16a to 16d operable as condensers are sequentially connected to the pipelines 17a to 17f.
And a first on-off valve 18 having a check function for preventing a flow toward the compressor is provided in a discharge pipe line 17a of the compressor 11, and a discharge pipe on the compressor side from the first on-off valve 18 is provided. Road 1
7a and the suction line 17f of the compressor are connected by an equalizing line 19 provided with a second on-off valve 20. On the other hand, when an overcurrent of a predetermined value or more flows through the motor of the compressor 11, this compression is performed. The compressor 11 is provided with a protection device 1 for stopping the compressor 11. When the compressor 11 is stopped, the determination means S2 for determining whether or not the stop is due to the protection device 1; when it is determined that whether, and at the same time starts to open for a predetermined time t ₁ of the second on-off valve 20, the expansion valve 15
While the fully closed, when the determining device S2 determines that affirmative, after a predetermined time t ₂ has elapsed from the start of opening for a predetermined time t ₁ of the second on-off valve 20, all the expansion valve 15 closes It is characterized by comprising control means S3, S4.

[0008] The indoor heat exchangers 16a to 16d are connected to the pipe 1
7d and 17e are provided in parallel via the respective indoor expansion valves 23a to 23d, and the control means S3 and S4 are provided with the determination means S
2 is determined to be no, the predetermined time of the second on-off valve 20
at the same time as the start of the opening of t _1, above all the indoor expansion valve 23a
While also fully closed the ～23D, when the determination means S2 is determined that the affirmative, the second from the start of opening for a predetermined time t ₁ after a predetermined time t ₂ has elapsed off valve 20, the entire indoor expansion valves 23a
To 23d may be fully closed.

[0009]

In the pressure equalizing device for an air conditioner according to the first aspect, it is assumed that the compressor 11 stops for some reason. The judging means S2 judges whether or not the stop of the compressor is caused by the protection device 1 which detects an overcurrent of the motor. When the judging means S2 judges no, the control means S3 and S4 determine the predetermined time t ₁ of the second on-off valve 20 of the pressure equalizing line 19 because of the normal stop.
Is started, and the expansion valve 15 is fully closed. Then, the high-temperature, high-pressure refrigerant gas discharged from the compressor immediately before the stop is connected to the expansion valve 15 from the first opening / closing valve 18 of the discharge pipe 17a having the check function through the indoor heat exchangers 16a to 16d. When the second on-off valve 20 is opened, the discharge / suction pipes 17a, 17f of the compressor 11 are closed.
Equalization takes place between the two. Therefore, when the compressor 11 is restarted, the previous stop is not an overcurrent stop due to a start overload due to the high-pressure refrigerant gas sealed in the pipes 17e and 17d, but a normal stop. The starting load can be reduced only by equalizing the pressure between the discharge and suction sides of the compressor 11 by opening the two-way on-off valve 20, and the compressor 11 can be easily started while improving the rise of the heating capacity at the time of starting. it can.

On the other hand, when the determination means S2 is determined that the affirmative, the control means S3, S4 is, therefore stopped due to overcurrent, to start opening of the predetermined time t ₁ of the second on-off valve 20 of the equalizing pressure line 19 after the predetermined time t ₂ has elapsed from the expansion valve 15 is fully closed.
Then, the high temperature discharged from the compressor immediately before stop, high-pressure refrigerant gas flows to the downstream side in the opening of the predetermined time t ₂ of the expansion valve 15 under reduced pressure, during the expansion valve 15 from the first on-off valve 18 conduit 17e, the pressure of the refrigerant to be sealed in 17f, along with corresponding reduced than in the above case, before and after the pressure equalization of the second on-off valve 20 for a predetermined time t ₁ of the same compressor as above in Kaisei 11 also Done. Therefore, when the compressor 11 is restarted, the refrigerant pressure in the discharge-side pipes 17e and 17f is considerably low even if the previous stop is stopped due to the overload or overcurrent due to the sealed high-pressure refrigerant gas. The compressor 11 can be easily started by preventing the current from being stopped.

Further, in the pressure equalizing device according to the second aspect, the indoor heat exchangers 16a to 16d are connected to the indoor expansion valves 23a to 23d.
The control means S3 and S4 are provided in parallel with the pipelines 17d and 17e via the control unit.
3d is opened / closed in the same manner as the expansion valve 15 described above. Therefore, when the compressor 11 is stopped by the protection device 1 that has detected the overcurrent, the predetermined time t ₁ of the second on-off valve 20 is set.
After a predetermined time t ₂ has elapsed from the start opening of the entire indoor expansion valve 23
a to 23d are fully closed, and the first upstream expansion valve
Since the pressure of the refrigerant sealed in the pipelines 17e and 17d up to the on-off valve 18 and the downstream expansion valve 15 is reduced and the pressure equalization before and after the compressor 11 is performed, the overcurrent stop is performed. Is prevented, and the compressor 11 can be easily started. On the other hand, if the compressor 11 except overcurrent stop is stopped, simultaneously with the opening initiation of the predetermined time t ₁ of the second on-off valve 20,
All the indoor expansion valves 23a to 23d are fully closed, and high-pressure refrigerant is sealed in the upper and lower pipelines 17e and 17d on the indoor expansion valves, while equalizing the pressure before and after the compressor 11. From, while further improving the rise of heating capacity at startup,
The compressor 11 can be easily started.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 shows an example of an air conditioner equipped with a pressure equalizer of the present invention. This air conditioner has the same configuration as the refrigeration circuit described in FIG. 4 except that the configuration of the control unit 1 is different. This is the configuration, and the same members are given the same numbers. That is, the compressor 11, the four-way switching valve 12, the outdoor heat exchanger 13 having the fan 14, the expansion valve 15, and the respective indoor expansion valves 23
A plurality of indoor heat exchangers 16a to 16d having
a to 17f, and a discharge opening 17a provided with a first opening / closing valve 18 having a check function, while the discharge / suction piping 17a, 17f is provided with a second opening / closing valve 20 via an equalizing line. 1
9 is connected. Also, while detecting an overcurrent flowing to the motor of the compressor 11, the compressor 11 is stopped,
The control unit 1 also serves as a protection device for controlling the four-way switching valve 12, the expansion valve 15, the indoor expansion valves 23a to 23d, and the first and second on-off valves 18, 20.

The control section 1 constitutes a pressure equalizing device having a judgment means and a control means described later. That is, the control unit 1
As a determination means, when the compressor 11 is stopped (S in FIG. 3)
1), it is determined whether or not the stop is caused by the protection device that detects an overcurrent (see S2). The control unit 1 includes, as control means, when it is judged not to be the overcurrent stops (S4 see FIG. 3), so as to the control normal pressure equalization, start the opening of the predetermined time t ₁ of the second on-off valve 20 At the same time (see FIG. 2 (C)), the expansion valve 15 and the all-room expansion valves 23a to 23a-2
3d is fully closed (see the solid lines in FIGS. 2D and 2E). On the other hand, (see S3 in FIG. 3) when it is determined that the overcurrent stops, in order to the control pressure equalization during overcurrent, predetermined time to initiate the opening of a predetermined time t ₁ of the second on-off valve 20 t After ₂ elapses (Fig. 2 (D), (E)
), The expansion valve 15 and the expansion valves 23a to 23a
23d is fully closed.

The control unit 1 having the above configuration controls the air conditioner as follows in accordance with the timing chart of FIG. 2 and the flowchart of FIG. Now, an operation command from a control device not shown in FIG. 1 is turned off as shown in FIG. 2A, or a protection device in the control unit 1 detects an overcurrent of the compressor 11 and It is assumed that the machine has stopped as shown in FIG. Then, the control unit 1 determines in step S1 of FIG.
It is determined that the compressor is stopped, and in step S2, it is determined whether or not the stop of the compressor as the pressure equalizing device is caused by the protection device that detects the overcurrent of the motor.

If the answer is NO, the routine proceeds to step S4 because of a normal stop, and the second on-off valve 20
At the same time when starting the opening of a predetermined time t ₁ (see FIG. 2 (C)), all the indoor expansion valve 23a~23d and the expansion valve 15 is fully closed (see FIG. 2 (D), (E) ). Then, the high-temperature, high-pressure refrigerant gas discharged from the compressor immediately before the stoppage is transmitted from the first opening / closing valve 18 of the discharge pipe 17a having the check function to the indoor expansion valves 23a to 23d via the indoor heat exchanger 16. Conduit 17
e and the pipeline 1 from these indoor expansion valves to the expansion valve 15
7d, and the pressure equalization is performed between the discharge and suction pipe lines 17a and 17f of the compressor 11 by opening the second on-off valve 20. Therefore, when the compressor 11 is restarted, the previous stop is not an overcurrent stop due to a start-up overload due to the high-pressure refrigerant gas sealed in the pipelines 17e and 17d, but a normal stop. The starting load can be sufficiently reduced only by equalizing the pressure between the discharge and suction sides of the compressor 11 by opening the second on-off valve 20, and the compressor 11 can be easily started while improving the rise of the heating capacity at the time of starting. Can be.

On the other hand, if the judgment is affirmative in step S2, the operation proceeds to step S3 because of stoppage due to overcurrent, and
Initiate opening of predetermined time t ₁ of the second on-off valve 20 in 9 (FIG. 2
After (C) see) after after a predetermined time t ₂ has elapsed, all the indoor expansion valves 23a~23d and the expansion valve 15 is fully closed (FIG. 2 (D), the
(See the broken line in (E)). Then, the high temperature discharged from the compressor immediately before stop, high-pressure refrigerant gas is depressurized to flow to the downstream side of the expansion valve 15 in opening of the expansion valve 15 and the indoor expansion valve a predetermined time 23 a to 23 d t _2, the indoor The pressure of the refrigerant sealed in the pipe line 17e from the expansion valves 23a to 23d to the first opening / closing valve 18 on the upstream side and the pipe line 17d to the expansion valve 15 on the downstream side is controlled by the control in step S4 described above. The pressure is considerably reduced and the pressure equalization before and after the compressor 11 is performed. Therefore, the compressor 1
When restarting 1, the refrigerant pressure in the pipes 17e and 17d becomes considerably low even if the previous stop was an overload due to the high-pressure refrigerant gas sealed in the pipes 17e and 17d and a stop due to an overcurrent. Therefore, the rise of the heating capacity at the time of starting can be improved to some extent, and the overcurrent stop can be avoided, so that the compressor 11 can be started reliably. In other words, even when the compressor 11 stops due to an overcurrent, even pressure control is performed between the first on-off valve 18 and the expansion valve 15 to ensure restarting.
As a result, the rise of the heating capacity at the time of start-up is greatly improved as a whole as compared with the conventional example described above. In the above embodiment, the intermediate indoor expansion valves 23a to 23d are also opened and closed similarly to the expansion valve 15, so that even if some of these expansion valves are not properly closed, the high-pressure refrigerant is not sealed. Therefore, there is an advantage that the rise of the heating capacity at the time of starting can be more reliably improved.

The above embodiment is an example of the pressure equalizing device according to the second aspect. However, the control unit 1 as the control means does not control the indoor expansion valves 23a to 23d, and only the expansion valve 15 is used. The pressure equalizing device according to claim 1 may be configured to perform control in the same manner as described above. Even in this case, the first on-off valve 1
Since the same high-pressure refrigerant is sealed and the pressure of the refrigerant is reduced between the expansion valve 8 and the expansion valve 15, the same operations and effects as described above can be obtained. In the above embodiment, the refrigerant circuit for both cooling and heating, in which the circulation direction of the refrigerant is switched in the forward and reverse directions by the four-way switching valve 12, has been described.
It is needless to say that the present invention can be applied to a refrigerant circuit dedicated to heating in which the indoor heat exchanger functions only as a condenser.

[0018]

As is apparent from the above description, the pressure equalizing apparatus for an air conditioner of the present invention connects a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger sequentially through a pipeline, and discharges the air. A first on-off valve having a non-return function is provided in the pipeline, and the upstream side and the suction pipeline are connected by a pressure equalizing pipeline provided with a second on-off valve.
In an air conditioner equipped with a protection device that stops an compressor by detecting an overcurrent flowing through a motor, a determination unit determines whether the stop of the compressor is caused by the protection device, and the control unit determines the stop. If the means determines that it is no, the expansion valve is fully closed at the same time as the opening of the second on-off valve is started for a predetermined time, and if the determination means determines affirmative, the opening of the second on-off valve is started for a predetermined time. Since the expansion valve is fully closed after the lapse of a predetermined time, the high-pressure refrigerant is sealed between the first opening / closing valve and the expansion valve in cases other than the stop of overcurrent, and the heating capacity at the time of startup is increased. Can be improved, and in case of overcurrent stop,
Since the above-mentioned sealed refrigerant is decompressed to reduce overload at restart and ensure restart, the start-up of heating capacity is improved overall while avoiding restart at compressor start. can do.

Further, if a plurality of the indoor heat exchangers are provided in parallel via respective indoor expansion valves, and the control means controls the opening and closing of these indoor expansion valves in the same manner as the above expansion valves, The intermediate indoor expansion valve operates in the same way as the expansion valve,
Even if a part of these expansion valves is not properly closed, the high-pressure refrigerant can be sealed. Therefore, in addition to the above-described functions and effects, the improvement of the heating capacity can be more reliably improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of an air conditioner provided with a pressure equalizing device of the present invention.

FIG. 2 is a timing chart showing a control operation of the pressure equalizing device over time.

FIG. 3 is a flowchart showing a control flow of the pressure equalizing device.

FIG. 4 is a circuit diagram showing an air conditioner provided with a conventional pressure equalizing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Control part, 11 ... Compressor, 12 ... Four-way switching valve, 13 ...
Outdoor heat exchanger, 15: expansion valve, 16a to 16d: indoor heat exchanger, 17a: discharge line, 17b to 17e: line, 17f ...
Suction line, 18 ... 1st on-off valve, 19 ... Equalizing line, 20 ...
Second on-off valves, 23a to 23d: indoor expansion valves.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 1/00 F24F 11/02 102

Claims (2)

(57) [Claims] 1. A compressor (11), an outdoor heat exchanger (13) operable as an evaporator, an expansion valve (15), and an indoor heat exchanger (16a-16d) operable as a condenser are sequentially connected to a pipeline. (1
7a to 17f), and is connected to the discharge line (1) of the compressor (11).
7a), a first on-off valve (18) having a check function for preventing the flow toward the compressor is provided, and a discharge pipe line (17a) on the compressor side from the first on-off valve (18) is connected to the compressor. Is connected to the suction line (17f) by a pressure equalizing line (19) provided with a second on-off valve (20), while an overcurrent of a predetermined value or more flows through the motor of the compressor (11). A pressure equalizer (1) for an air conditioner equipped with a protection device (1) for stopping the compressor (11), wherein when the compressor (11) stops, the stop is performed by the protection device (1). Judgment means (S2) for judging whether or not it is based on (1)
And when the determination means (S2) determines that the second on-off valve (20) is open for a predetermined time (t ₁ ),
While the expansion valve (15) is fully closed, the judgment means (S2)
A predetermined time for the second on-off valve (20)
After elapse of a predetermined time (t ₂ ) from the start of opening of (t ₁ ), the air conditioner is equipped with control means (S3, S4) for fully closing the expansion valve (15). Pressure device. 2. A plurality of said indoor heat exchangers (16a to 16d) are provided in parallel in pipelines (17d, 17e) via respective indoor expansion valves (23a to 23d), and said control means (S3, S4)
When the determination means (S2) determines that no, the second
At the same time that the opening and closing of the on-off valve (20) for a predetermined time (t ₁ ) is started and the all-room expansion valves (23a to 23d) are also fully closed, while the judgment means (S2) judges affirmatively, Second
The predetermined time (t ₁₎ predetermined time from the start of opening of (t ₂₎ after the closing valve (20), claims the entire indoor expansion valve (23 a to 23 d) also becomes the fully closed so 2. The pressure equalizing device for an air conditioner according to 1.