JPH09133439A - Method and device for controlling accumulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable starting the operation without occurrence of deficiency in lubrication of a compressor and a trouble on liquid compression by contriving outflow of oil singly during the starting of operation of a freezing cycle when a refrigerant and oil merge in a two-phase separation state into an accumulator, in an accumulator of a freezing cycle. SOLUTION: In a freezing cycle using an alternate refrigerant and oil incompatible therewith, after a refrigerant G and oil O are stored at an accumulator 7 once, the refrigerant and the oil are returned to a compressor in such a manner that during a time between the starting of operation on a condition that the refrigerant G and the oil O merge in a two-phase separation state and cancellation of the condition, internal fluid is returned from the upper part of the accumulator 7 and only the oil O at an upper layer is fed to the compressor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an accumulator and an apparatus therefor, and more particularly to a refrigerant and an oil accumulator in a refrigerant circulation path of a refrigeration cycle using an alternative refrigerant and oil incompatible with the accumulator. The present invention relates to a control method and an apparatus for an accumulator when it is once stored and then returned to a compressor of a refrigeration cycle.

[0002]

2. Description of the Related Art Generally, in a heat pump type air conditioner, as shown in FIG. 11, a compressor a, a four-way valve b, an indoor heat exchanger c, a pressure reducer d, and an outdoor heat exchanger e are sequentially connected by a circulation path f. And constitutes a heat pump type refrigeration cycle. An accumulator g is provided in the portion of the circulation path f on the suction side of the compressor a, and while the refrigerant and the oil are stored, the refrigerant and the oil are returned to the compressor a to be lubricated and the refrigerant is supplied to the refrigeration cycle. .

In such a refrigeration cycle, during cooling operation, the four-way valve b is switched to the cooling side shown by the solid line in the figure.
As a result, the refrigerant discharged from the compressor a flows into the four-way valve b.
To the outdoor heat exchanger e, where it is condensed and then decompressed by the decompressor d to partially gasify, and flows to the indoor heat exchanger c where it cools the room and evaporates, It is sucked into the compressor a through the four-way valve b.

On the other hand, during the heating operation, the four-way valve b is switched to the heating side shown by the broken line in the figure. As a result, the refrigerant discharged from the compressor a flows through the four-way valve b to the indoor heat exchanger c, where the inside of the room is heated and condensed, and then decompressed by the decompressor d to partially gasify. , Flows to the outdoor heat exchanger e, evaporates there, and is sucked into the compressor a via the four-way valve b.

[0005]

However, when the above refrigeration cycle is operated by heating using an alternative refrigerant for a specific CFC, such as an HFC refrigerant, and an oil that is incompatible with the refrigerant, in order to protect the environment, the compressor is compressed. Insufficient lubrication or liquid compression sometimes occurs in the machine a, and the compressor a is overloaded. This leads to an early failure of the compressor a, and is particularly a problem when a maintenance-free hermetic compressor a is used.

Such a problem occurs in the case of the conventional accumulator g as shown in FIG. The alternative refrigerant does not dissolve in the incompatible oil, and when the operation is stopped for a certain period of time due to the low outdoor temperature during heating, in the accumulator g, as shown in the figure, the refrigerant h is below and the oil i is below the oil i. Refrigerant and oil lie in the upper two-phase separated state. However, the return hole k of the outlet pipe j of the accumulator g is opened in the lower part inside the accumulator g as shown in the figure. Therefore, at the start of the heating operation, only the refrigerant flows from the accumulator g, and the oil is not supplied from the accumulator g to the compressor a. This is the cause of insufficient lubrication of the compressor a, and the liquid refrigerant is sucked into the compressor a, which causes a problem of liquid compression.

In a refrigerating cycle used for a heat pump type refrigerator that does not perform heating, such a situation sometimes occurs at the start of operation after a certain period of rest in winter when the indoor temperature decreases.

Japanese Unexamined Patent Publication (Kokai) No. 3-236568 discloses that the outlet pipe of the accumulator is provided with a large return hole opening to the upper part in the accumulator and a small return hole opening to the lower part in the accumulator. . With this product, even if the refrigerant and oil lie in the accumulator in a two-phase separated state, the large return hole in the upper part allows the oil in the upper layer to flow out without difficulty, and satisfies the lubrication of the compressor. The refrigeration cycle is also started by discharging it from the.

However, the refrigerant at this time is a liquid refrigerant, which is sucked into the compressor and compressed, so that the problem of liquid compression cannot be solved.

An object of the present invention is to solve such a problem, and when the refrigerating cycle is started when the refrigerant and the oil lie in the accumulator in a two-phase separated state, the oil is sought to flow out independently of the compressor. It is an object of the present invention to provide a control method of an accumulator and a device therefor which can be started up without problems of insufficient lubrication and liquid compression.

[0011]

According to a first aspect of the present invention, there is provided a method for controlling an accumulator, wherein refrigerant and oil are temporarily accumulated in an accumulator in a refrigerant circulation path of a refrigeration cycle using an alternative refrigerant and oil incompatible with the refrigerant. After returning to the compressor of the refrigeration cycle, only during the period from the start of operation of the refrigeration cycle under the condition that refrigerant and oil lie in the two-phase separated state in the accumulator until the above condition is resolved, Return the internal fluid from the upper part so that the upper oil is supplied to the compressor,
Other than that, the internal fluid is returned from the lower part of the accumulator so that the refrigerant and oil are supplied to the compressor.The operation of the refrigeration cycle under the condition that the refrigerant and oil lie in the accumulator in the two-phase separation state. Even at the start, the internal fluid is returned from the upper part of the accumulator until the above conditions are resolved, so the oil sunk in the upper part of the accumulator is allowed to flow out alone and supplied to the compressor to lubricate it. As a result, the compressor can be satisfactorily lubricated regardless of the stagnation of the refrigerant and the oil in the two-phase separated state, and the refrigerant sunk as a liquid in the lower part of the accumulator cannot flow out. Without being sucked into the compressor and causing liquid compression, the refrigeration cycle can be started up without problems. When the condition of stagnation in the two-phase separation state disappears due to the rise of the refrigeration cycle, the internal fluid is returned from the lower part of the accumulator, so the refrigerant and oil that have become gasified or easily gasified are supplied to the compressor, and the refrigeration cycle starts. It can be achieved as usual.

According to a second aspect of the present invention, there is provided a control device for an accumulator, wherein the same accumulator provided in the refrigerant circulation path of the refrigeration cycle has a first outlet pipe having a return hole in an upper part of the accumulator and an accumulator. A second outlet pipe having a return hole in the lower part of the first and second opening / closing means for individually opening / closing the first and second outlet pipes, and a two-phase separated state of refrigerant and oil. The determination means for determining the presence / absence of the sleeping condition and the first opening / closing means and the second opening / closing means are closed only while the determination of the sleeping condition is performed by the determination means, and the determination of the sleeping condition is not performed. In this case, the first opening / closing means is closed, and the opening / closing control means for controlling the second opening / closing means to be opened is provided, and the stagnation condition in the two-phase separated state of the refrigerant and the oil is determined by the determination means. During opening and closing control means is judgment,
Since the second opening / closing means is closed to close the second outlet pipe and the first opening / closing means is opened to return the internal fluid from the upper part of the accumulator through the first outlet pipe, the oil sunk in the upper part is isolated. It is possible to prevent the liquid refrigerant lying in the lower part of the accumulator from flowing out to the compressor by being supplied to the compressor to be lubricated, and being sucked into the compressor to cause liquid compression. Further, in the state where the sleeping condition is not determined, the opening / closing control unit closes the first opening / closing unit to close the first outlet pipe, opens the second opening / closing unit, and opens the second outlet pipe from the lower portion of the accumulator. Since the internal fluid is returned, the refrigerant and oil that are gasified or easily gasified are supplied to the compressor so that the normal refrigeration cycle operation can be performed. Therefore, the method of the invention of claim 1 can be achieved automatically.

According to a third aspect of the present invention, there is provided a control device for an accumulator, wherein the first and second accumulators are provided in parallel with each other by a branch path in the middle of the refrigerant circulation path of the refrigeration cycle, and the inside of the first accumulator. A first outlet pipe having a return hole in the upper part of the first accumulator and a second outlet pipe having a return hole in the lower part of the second accumulator, and the first and second accumulators of the first and second accumulators. First and second opening / closing means for individually opening / closing each branch path of
Judgment means for judging the presence or absence of the stagnation condition in the two-phase separation state of the refrigerant and the oil, and the first opening / closing means is opened and the second opening / closing means is closed only while the judgment means determines the stagnation. An opening / closing control means for controlling the first opening / closing means to be closed and the second opening / closing means to be opened when there is no determination of the sleeping condition is provided. While the sleeping condition is being determined by the determining means, the opening / closing control means closes the second opening / closing means to shut off the second accumulator from the refrigeration cycle due to the blockage of the second branch path associated therewith. Since the opening / closing means is opened so that the first accumulator communicates with the refrigeration cycle through the first branch path associated therewith, the first accumulator has a stagnation condition in the two-phase separated state of the refrigerant and the oil, Akyu of 1 It is possible to return the internal fluid of the generator from the return hole in the upper part of the first outlet pipe, and to discharge only the oil lying in this upper part and supply it to the compressor, thereby eliminating the lack of lubrication of the compressor. It is possible to prevent the liquid refrigerant lying in the lower part of each of the first and second accumulators from flowing out and being supplied to the compressor to be in liquid compression. Also, when there is no determination of the sleeping condition,
The opening / closing control means closes the first opening / closing means to shut off the first accumulator from the refrigeration cycle by closing the first branch passage, and opens the second opening / closing means to open the second accumulator in the second branch passage. The internal fluid of the second accumulator is connected to the second
Return from the lower return hole in the outlet pipe of
Alternatively, the refrigeration cycle can be normally operated by supplying the refrigerant and oil that have been easily gasified to the compressor. Therefore, the method of the invention of claim 1 can be achieved automatically.

According to a fourth aspect of the present invention, in any one of the second and third aspects of the present invention, the determination means makes a determination based on a result of comparison between the refrigerant discharge temperature of the compressor of the refrigeration cycle and the reference temperature. The invention according to claim 5 is the invention according to any one of claims 2 and 3, wherein the determining means determines based on a result of comparison between the temperature of the shell of the compressor of the refrigeration cycle and the reference temperature. In any one of the inventions of claims 2 and 3, the determining means makes a determination based on a result of comparison between the measurement time from the start of the heating operation of the refrigeration cycle and the reference time, and any one of claims 4 to 6 Also in the invention, the presence or absence of the stagnation condition in the two-phase separated state of the refrigerant and the oil is automatically determined, and any of the inventions of claims 2 and 3 can be reliably achieved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) This embodiment shows a case where it is applied to a refrigeration cycle of a heat pump type air conditioner. As shown in FIG. 1, a compressor 1, a four-way valve 2, an indoor heat exchanger 3, The decompressor 4 and the outdoor heat exchanger 5 are sequentially connected by the circulation path 6 to form a heat pump type refrigeration cycle, and an alternative refrigerant, for example, an HFC-based refrigerant and an oil incompatible with the refrigerant are used. An accumulator 7 is provided in a portion of the circulation path 6 on the suction side of the compressor 1, and the refrigerant is supplied to the circulation path 6 while accumulating the refrigerant and the oil therein, and the oil is mainly a mechanical sliding portion of the compressor 1. To lubricate the portion, and the refrigerant is compressed by the compressor 1 for use in the refrigeration cycle.

In such a refrigerating cycle, the four-way valve 2 can be switched to the cooling side shown by the solid line in FIG. 1 during the cooling operation. As a result, the refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 5 via the four-way valve 2, is condensed there, and then reaches the pressure reducer 4 to be depressurized and partly gasified,
It flows to the indoor heat exchanger 3, where the room is cooled to evaporate, and is sucked into the compressor 1 via the four-way valve 2.

On the other hand, during the heating operation, the four-way valve 21 is switched to the heating side shown by the broken line in the figure.

As a result, the refrigerant discharged from the compressor 1 flows through the four-way valve 2 to the indoor heat exchanger 3, where the room is heated and condensed, and the pressure is reduced by the pressure reducer 4 so that a part of the gas is discharged. And flows into the outdoor heat exchanger 5, where it is evaporated and then sucked into the compressor 1 via the four-way valve 2.

When the refrigeration cycle is operated in the heating mode, insufficient lubrication or liquid compression sometimes occurs in the compressor 1 and the compressor 1 is overloaded. However, in the present embodiment,
In the circulation path 6 of the refrigerant of the refrigeration cycle using the alternative refrigerant and the oil incompatible with the refrigerant, the refrigerant and the oil are temporarily stored in the accumulator 7 and then returned to the compressor 1 of the refrigeration cycle. The internal fluid is returned from the upper part of the accumulator 7 and the upper layer oil is supplied to the compressor 1 only from the start of the operation of the refrigeration cycle under the condition that lie in the two-phase separated state until the above condition is resolved. Otherwise, the internal fluid is returned from the lower part of the accumulator 7 so that the refrigerant and the oil are supplied to the compressor 1.

Therefore, even if the operation of the refrigeration cycle is started under the condition that the refrigerant and the oil lie in the accumulator 7 in the two-phase separated state, the upper part of the accumulator 7 is kept until the condition is canceled. The internal fluid is returned from the above, and the oil sunk in the upper part is spilled out independently and is supplied to the compressor 1 to lubricate it. Therefore, the compressor 1 is irrespective of the stagnation in the two-phase separated state of the refrigerant and the oil. Can be satisfactorily lubricated. In addition, it is possible to avoid that the refrigerant that has become a liquid in the lower part of the accumulator 7 does not flow out and is sucked into the compressor 1 to cause liquid compression.

Therefore, the refrigeration cycle can be started up without any problem. When the condition for sleeping in the two-phase separated state disappears due to the rise of the refrigeration cycle, the internal fluid is returned from the lower part of the accumulator 7, so that the gasified or easily gasified refrigerant and oil are supplied to the compressor 1 for refrigeration. The cycle can be accomplished normally.

In order to automatically control the accumulator 7 as described above, the accumulator 7 as shown in FIGS. 1 and 3 is used in the present embodiment. The accumulator 7 is provided in the middle of the refrigerant circulation path 6 of the refrigeration cycle as shown in FIG. 1, and has a first outlet pipe 7b having a return hole 7a in the upper part of the accumulator 7 and a lower part in the accumulator 7. A second outlet pipe 7d having a return hole 7c formed therein is provided, and each solenoid valve 15 as first and second opening / closing means for individually opening / closing each of the first and second outlet pipes 7b, 7d. , 16 are provided.

A microcomputer 13 for controlling the operation of the refrigerating cycle of the present embodiment as shown in FIG. 2 is used for the above control, and the internal function of the microcomputer 13 causes the refrigerant and the oil to lie in a two-phase separated state. The first solenoid valve 15 is opened only while the determination unit 17 for determining the presence or absence of the condition and the determination of the sleeping condition by the determination unit 17 are opened.
The second electromagnetic valve 16 is closed, and when there is no determination of the sleeping condition, the first electromagnetic valve 15 is closed, and the opening / closing control means 12 for controlling the second electromagnetic valve 16 to open is provided, and the determination means 17 is provided. Is determined by the comparison result of the comparison means 11 between the refrigerant discharge temperature T1 detected by the temperature sensor 9 of the compressor 1 and the reference temperature T0. This comparison means 11 also uses the internal function of the microcomputer 13. However, the present invention is not limited to this, and it is possible to use separate microcomputers or dedicated circuits and devices for each. In addition, the four-way valve 2 is also operated by an actuator that operates electromagnetically,
A mode setting from the operation panel 14 allows switching between a cooling state and a heating state.

In such a structure, the refrigerant discharge temperature T1 of the compressor 1 is detected by the temperature sensor 9 and is input to the microcomputer 13. In the microcomputer 13, the comparison means 11 compares the detected temperature T1 with a preset reference temperature T0. Judgment means 1
7 indicates the refrigerant discharge temperature T according to the comparison result.
Whether 1 is the reference temperature T0 or less determines whether or not the refrigerant and the oil are in the stagnation condition in the two-phase separated state.

The opening / closing control means 12 closes the second solenoid valve 16 to close the second outlet pipe 7 while the bed condition in the two-phase separation state of the refrigerant and the oil is being judged by the judging means.
d is closed and the first solenoid valve 15 is opened to open the first outlet pipe 7
Since the internal fluid is returned from the upper part of the accumulator 7 through b, the oil O sunk in the upper part of the accumulator 7 can be separately supplied to the compressor 1 to be lubricated, and the liquid refrigerant sunk in the lower part of the accumulator 7 can be supplied. It is possible to prevent G from flowing out and being sucked into the compressor 1 to cause liquid compression.

Further, in a state where the refrigerant discharge temperature T1 becomes equal to or lower than the reference temperature T0 and the sleep condition is not judged by the judging means 17, the opening / closing control means 12 closes the first electromagnetic valve 15 to close the first outlet pipe. 7b is closed, the second solenoid valve 16 is opened, and the internal fluid is returned from the lower part of the accumulator 7 through the second outlet pipe 7d. Therefore, the refrigerant G and the oil O which are easily gasified or gasified Is supplied to the compressor 1 so that normal refrigeration cycle operation can be performed.

(Embodiment 2) This embodiment follows the basic configuration of the first embodiment as shown in FIG. 4, and the determining means 17 determines that the temperature T3 of the shell of the compressor 1 The only difference is that the presence or absence of stagnation in the two-phase separated state of the refrigerant and the oil is determined based on the result of comparison with the reference temperature T2. For this determination, the shell temperature T3 is detected by the temperature sensor 21 as shown in FIG. 4, and this is compared with the reference temperature T2 by the comparison means 22 utilizing the internal function of the microcomputer 13 as shown in FIG. Based on this comparison result, the determination means 17 is configured to determine whether or not there is a stagnation condition in the two-phase separated state of the refrigerant and the oil by specifically determining whether or not the shell temperature T3 is equal to or lower than the reference temperature T2. There is. This also makes it possible to accurately determine whether or not the refrigerant and the oil have stagnated in the two-phase separated state, and to achieve the same effects as in the case of the first embodiment.

(Embodiment 3) In this embodiment, as shown in FIG. 6, the basic configuration of the first embodiment is followed, and the determination means 17 measures from the start of heating operation of the refrigeration cycle. The only difference is that the determination is made based on the comparison result between the time t1 and the reference time t0. For this determination, the heating operation time measuring means 31 for measuring the operation time from the start of the heating operation and the comparing means 3 for comparing the measurement time t1 by the heating operation time measuring means 31 with the reference time t0.
2 is provided by utilizing the internal function of the microcomputer 13, and the determining means 17 determines whether the refrigerant and the oil are in accordance with the comparison result by the comparing means 32, specifically, whether the measurement time t1 is t0 or more. It is designed to determine whether there is a sleeping condition in the two-phase separation state. This also makes it possible to accurately determine whether or not the refrigerant and the oil have stagnated in the two-phase separated state, and to achieve the same effects as in the case of the first embodiment. Note that the temperature sensor is not necessary in this embodiment.

(Embodiment 4) This embodiment is shown in FIG.
As shown in FIG. 10, the first and second accumulators 71 and 72 are connected to the circulation path 6 in parallel by dedicated first and second branch paths 6a and 6b, respectively.
A refrigerating cycle different from that of the above embodiment is configured.
Then, as shown in FIG. 10, the first accumulator 71 has a first return hole 71a formed in the upper portion thereof.
A second accumulator 72 having an outlet pipe 71b of
Has a second outlet pipe 72b in which a return hole 72a is opened in the lower portion thereof. Electromagnetic valves 41 and 42 are provided as first and second opening / closing means for individually opening / closing the first and second branch paths 6a and 6b of the first and second accumulators 71 and 72, respectively.

Further, similarly to the case of the first embodiment, the judging means 17 is provided by utilizing the internal function of the microcomputer 13 together with the comparing means 11, and the comparing means 11 is provided.
Refrigerant discharge temperature T1 of the compressor 1 from the temperature sensor 9
The presence or absence of the stagnation condition in the two-phase separation state of the refrigerant and the oil is determined on the basis of the comparison result between the reference temperature T0 and the reference temperature T0. The opening / closing control means 43 for controlling the valve 41 to open and the second solenoid valve 42 to close, and the first solenoid valve 41 to close and the second solenoid valve 42 to open when the sleeping condition is not determined. It is provided by utilizing the internal function of the microcomputer 13. Other configurations are the same as those in the first embodiment. The first and second solenoid valves 4
1, 42 may be provided on the downstream side of each of the first and second accumulators 71, 72 in the branch paths 6a, 6b.

In such a configuration, the opening / closing control means 43 closes the second electromagnetic valve 42 and the second solenoid valve 42 is closed while the determination means determines whether or not the sleeping condition exists in the two-phase separation state of the refrigerant and the oil. The accumulator 72 is blocked from the refrigeration cycle due to the blockage of the second branch path 6b relating to this.
The first solenoid valve 41 is opened to open the first accumulator 71.
Is connected to the refrigeration cycle in the first branch path 6a related to this, so that the internal fluid of the first accumulator 71 can be discharged despite the stagnation condition in the two-phase separation state of the refrigerant and the oil. By returning from the upper return hole 71a provided in the first outlet pipe 71b, only the oil lying in this upper portion can be discharged and supplied to the compressor 1,
Insufficient lubrication of the compressor 1 is eliminated, and it is avoided that the liquid refrigerant lying in the lower portions of the first and second accumulators 71, 72 flows out and is supplied to the compressor 1 to become liquid compression. be able to.

Further, in the state where the sleeping condition is not judged,
The opening / closing control means 43 closes the first electromagnetic valve 41 to disconnect the first accumulator 71 from the refrigeration cycle by closing the first branch path 6a, and opens the second electromagnetic valve 42 to open the second accumulator 72. To communicate with the refrigeration cycle in the second branch path 6b, the internal fluid of the second accumulator 72 is returned from the lower return hole 72a provided in the second outlet pipe 72b to be gasified or gasified. The refrigerating cycle can be normally operated because the refrigerant and the oil that have become easier are supplied to the compressor 1. Therefore, the same operational effect as that of the first embodiment can be exhibited.

Although not shown, the same effect can be obtained by applying each of the judging means shown in the second and third embodiments as the judging means of this embodiment. It belongs to the category of invention.

[0035]

According to the method of controlling the accumulator of the first aspect of the present invention, the lubrication of the compressor is satisfied at the start of the operation of the refrigeration cycle under the condition that the refrigerant and the oil lie in the accumulator in the two-phase separated state. In addition, the refrigeration cycle can be achieved normally after the refrigeration cycle has been started up without problems, and that the liquid refrigerant is sucked into the compressor and causes liquid compression.

According to the accumulator control device of the second to sixth aspects of the invention, the method of the first aspect of the invention can be automatically achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a heat pump type refrigeration cycle showing a first embodiment of a method for controlling an accumulator and an apparatus therefor according to the present invention.

FIG. 2 is a block diagram of a control circuit of the refrigeration cycle in FIG.

FIG. 3 is a sectional view of an accumulator in the refrigeration cycle of FIG.

FIG. 4 is a schematic diagram of a heat pump type refrigeration cycle showing a second embodiment of the control device for the accumulator according to the present invention.

5 is a block diagram of a control circuit of the refrigeration cycle of FIG.

FIG. 6 is a schematic diagram of a heat pump type refrigeration cycle showing a third embodiment of the control device for the accumulator according to the present invention.

7 is a block diagram of a control circuit of the refrigeration cycle of FIG.

FIG. 8 is a schematic diagram of a heat pump type refrigeration cycle showing a fourth embodiment of a control device for an accumulator according to the present invention.

9 is a block diagram of a control circuit of the refrigeration cycle of FIG.

10 is a sectional view of an accumulator used in the refrigeration cycle of FIG.

FIG. 11 is a schematic diagram showing a conventional heat pump refrigeration cycle.

12 is a cross-sectional view of an accumulator used in the refrigeration cycle of FIG.

[Explanation of symbols]

 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Pressure reducer 5 Outdoor heat exchanger 6 Circulation path 6a, 6b Branch path 7, 71, 72 Accumulator 7a, 7c, 71a, 72a Return hole 7b, 7d, 71b, 72b Exit Pipes 15, 16, 41, 42 Solenoid valves 9, 21 Temperature sensors 12, 43 Opening / closing control means 13 Microcomputer 14 Operation panel 17 Judging means 31 Measuring means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshinori Kobayashi Yoshinori Kobayashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Akira Fujitaka 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Yamaguchi Adult, 1006 Kadoma, Kadoma City Osaka Prefecture 1006 Kadoma, Kadoma-shi, Fuchu Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. A refrigeration cycle refrigerant circuit using an alternative refrigerant and oil incompatible with the refrigeration cycle, wherein the refrigerant and oil are temporarily stored in an accumulator and then returned to the compressor of the refrigeration cycle. The internal fluid is returned from the upper part of the accumulator and the upper layer oil is supplied to the compressor only from the start of the operation of the refrigeration cycle under the condition that the oil falls asleep in the two-phase separated state until the above condition is resolved. A control method for the accumulator, characterized in that the internal fluid is returned from the lower part of the accumulator so that refrigerant and oil are supplied to the compressor. 2. A first outlet pipe having a return hole in the upper part of the accumulator and a second outlet pipe having a return hole in the lower part of the accumulator in the same accumulator provided in the middle of the refrigerant circulation path of the refrigeration cycle. Judgment for determining whether or not there is an outlet pipe, first and second opening / closing means for individually opening / closing each of the first and second outlet pipes, and a sleeping condition in a two-phase separated state of refrigerant and oil The first opening / closing means and the second opening / closing means are closed only while the sleeping condition is determined by the means and the determining means, and the first opening / closing means is closed when the sleeping condition is not determined, An accumulator control device, comprising: an opening / closing control means for controlling to open the second opening / closing means. 3. A first accumulator and a second accumulator, which are provided in parallel with each other by a branch passage in the middle of the circulation path of the refrigerant of the refrigeration cycle, and the first accumulator having a return hole in an upper portion thereof. An outlet pipe and a second outlet pipe having a return hole in the lower part of the second accumulator, and opening and closing the first and second branch passages of the first and second accumulators individually The first and second opening / closing means, the judging means for judging the presence or absence of the sleeping condition in the two-phase separation state of the refrigerant and the oil, and the first opening / closing means only while the judging means judges the sleeping. Open and close the second opening / closing means, and if there is no determination of the sleeping condition, first
And a second opening / closing means for controlling the second opening / closing means to be closed, and an accumulator control device. 4. The accumulator control device according to claim 2, wherein the determination means makes a determination based on a comparison result between the refrigerant discharge temperature of the compressor of the refrigeration cycle and the reference temperature. 5. The control device for the accumulator according to claim 2, wherein the determination means makes the determination based on a result of comparison between the temperature of the shell of the compressor of the refrigeration cycle and the reference temperature. 6. The accumulator according to claim 2, wherein the determination unit makes a determination based on a result of comparison between the reference time and the measurement time from the start of the heating operation of the refrigeration cycle.