JP6338698B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus.

  The refrigeration cycle apparatus includes, for example, a compressor that compresses and discharges refrigerant. When the compressor is, for example, a rotary compressor or the like, the compressor includes a compression mechanism including a rotating piston and a cylinder that houses the piston. In the compression mechanism portion, the piston and the cylinder slide, so that the piston and the cylinder are worn by friction. For this reason, the refrigerating machine oil which suppresses friction of a piston and a cylinder is stored in the compressor.

  Here, when the compressor is operating, the refrigerating machine oil flows out through the discharge pipe together with the refrigerant. When the refrigeration oil flows out of the compressor, it stays in each component such as a pipe and a heat exchanger that constitute the refrigerant circuit of the refrigeration cycle apparatus. Thus, when the refrigeration oil in the compressor flows out, the refrigeration oil in the compressor is insufficient, which may cause poor lubrication of the compression mechanism.

In order to prevent poor lubrication of the compression mechanism portion of the compressor, a refrigeration cycle apparatus has been proposed that uses a mechanism that separates discharged refrigeration oil with an oil separator and returns it to the suction side of the compressor. Here, immediately after starting up the compressor, the amount of refrigerating machine oil that flows out of the compressor increases more than during continuous operation. This is because immediately after starting the compressor, the liquid refrigerant in the compressor is rapidly vaporized and foamed, and the refrigeration oil flows out together with the refrigerant.
The continuous operation refers to, for example, not immediately after starting the compressor but when the operation of the compressor is stabilized after a preset time has elapsed after starting the compressor. Even if an oil separator is provided in the refrigeration cycle apparatus, it is assumed that the refrigeration oil overflows inside the oil separator and the refrigeration oil flows out from the pipe through which the refrigerant flows.

  Therefore, a conventional refrigeration cycle apparatus has been proposed in which a return oil pipe line that is opened during continuous operation and a return oil pipe that is attached to the lower part of the oil separator and that is opened at start-up are connected to the oil separator. (For example, refer to Patent Document 1). In the refrigeration cycle apparatus described in Patent Document 1, since the oil return pipe and the oil return pipe described above are provided, the oil stored in the oil separator before the start is easily returned to the suction side due to the pressure difference immediately after the start. Therefore, the shortage of lubricating oil in the compressor is suppressed.

Japanese Patent Laid-Open No. 11-108474

  In the configuration in which the refrigerating machine oil stored in the oil separator is returned when the compressor is started, if the amount of refrigerating machine oil stored in the oil separator is large, the oil level is increased by the refrigerant flowing into the oil separator. It becomes easy to swell. When the oil level undulates, the refrigeration oil in the oil separator scatters and flows out of the oil separator together with the refrigerant. As described above, when the compressor is started, the configuration in which the refrigerating machine oil stored in the oil separator is returned has a problem that the refrigerating machine oil flows out from the oil separator together with the refrigerant, and the oil separation efficiency is reduced.

  The present invention has been made in order to solve the above-described problems. Even when a configuration in which refrigeration oil is returned when the compressor is started, the oil separation efficiency in the oil separator is reduced. It aims at providing the refrigerating-cycle apparatus which suppresses that.

A refrigeration cycle apparatus according to the present invention is provided in a refrigerant discharge side of a compressor in a refrigeration cycle apparatus including a refrigerant circuit including a compressor, a condenser, a throttle device, and an evaporator, and separates the refrigerant and the refrigeration oil. An oil separator, an oil reservoir connected to the oil separator, and storing a refrigerating machine oil, and a flow rate adjusting device for adjusting the flow rate of the refrigerating machine oil, so that the oil overflowing from the oil storing section is returned to the compressor. A first oil return portion connected to the storage portion and the suction side of the compressor, and a first opening / closing device that can be opened and closed; one end of the oil return portion is connected to the first oil return portion and the oil storage portion. It is connected to an oil reservoir to be located in a lower portion, the other end is connected to a refrigerant suction side of the compressor, and a second oil return portion for returning the refrigerating machine oil stored in the oil reservoir in the compressor, an oil separator With the oil return pipe which connects a container and an oil storage part, and the 1st oil return part and the 2nd oil return part And connected to the suction side of the compressor accumulator, the accumulator connection pipe connected to the accumulator and the first switching device is opened when starting the compressor, the refrigerating machine oil stored in the oil reservoir compressor And a control device that closes the first opening / closing device after returning to the storage, and the oil storage section is connected to the storage container for storing the refrigeration oil, one end connected to the upper part of the storage container, and the other end to the oil return pipe A connection pipe connected to the first oil return part and extending from the lower side to the upper side from the upper part of the storage container to the first oil return part, and one end of the accumulator connection pipe is connected to the oil return pipe. Of these, the connection position between the connection pipe and the first oil return portion is connected to the oil separator side, the other end of the accumulator connection pipe is connected to the accumulator, and the accumulator connection pipe is provided with a third switching device. Control device, compressor When starting is to the third switching device opened.

  According to the refrigeration cycle apparatus according to the present invention, since the oil storage section that stores the refrigeration oil is provided separately from the oil separator, even if the configuration for returning the refrigeration oil when the compressor is started is employed, It is possible to provide a refrigeration cycle apparatus that suppresses a reduction in oil separation efficiency in the separator.

1 is a schematic configuration diagram of a refrigeration cycle apparatus 100 according to Embodiment 1 of the present invention. It is explanatory drawing about the structural example etc. of the connecting pipe. It is the modification 1 (refrigeration cycle apparatus 101) of the refrigeration cycle apparatus 100 which concerns on Embodiment 1 of this invention. It is the modification 2 (refrigeration cycle apparatus 102) of the refrigeration cycle apparatus 100 which concerns on Embodiment 1 of this invention. It is the modification 3 (refrigeration cycle apparatus 103) of the refrigeration cycle apparatus 100 which concerns on Embodiment 1 of this invention. It is the modification 4 (refrigeration cycle apparatus 104) of the refrigeration cycle apparatus 100 which concerns on Embodiment 1 of this invention. It is the modification 5 of the refrigerating-cycle apparatus 100 which concerns on Embodiment 1 of this invention. It is an example of the control flowchart of the refrigerating-cycle apparatus 100 which concerns on Embodiment 1 of this invention. It is an example of the control flowchart of the refrigerating-cycle apparatus 101 which concerns on Embodiment 1 of this invention. It is an example of the control flowchart of the refrigerating-cycle apparatus 102 which concerns on Embodiment 1 of this invention. It is an example of the control flowchart of the refrigerating-cycle apparatus 104 which concerns on Embodiment 1 of this invention. The schematic block diagram of the refrigerating-cycle apparatus 200 which concerns on Embodiment 2 of this invention is shown. It is the modification 1 (refrigeration cycle apparatus 201) of the refrigeration cycle apparatus 200 which concerns on Embodiment 2 of this invention. It is modification 2 (refrigeration cycle apparatus 202) of the refrigeration cycle apparatus 200 which concerns on Embodiment 2 of this invention. It is the modification 3 of the refrigerating-cycle apparatus 200 which concerns on Embodiment 2 of this invention. It is an example of the control flowchart of the refrigerating-cycle apparatus 200 which concerns on Embodiment 2 of this invention. It is an example of the control flowchart of the refrigerating-cycle apparatus 201 which concerns on Embodiment 2 of this invention. It is an example of the control flowchart of the refrigerating-cycle apparatus 202 which concerns on Embodiment 2 of this invention. It is an example of the control flowchart of the refrigerating-cycle apparatus 204 which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1A1 shows a schematic configuration diagram of a refrigeration cycle apparatus 100 according to the present embodiment. A solid line connecting each component in the figure indicates piping. The arrows in the figure indicate the flow of fluid while the refrigeration cycle apparatus 100 is operating, and the thin solid line and the broken line indicate the flow of the refrigerant. The thin solid arrow and the broken arrow indicate that the operation has been switched such as heating and cooling, and the flow direction of the refrigerant has changed. Moreover, the thick solid line arrow has shown the flow of the refrigerating machine oil containing refrigerant gas.

[Description of configuration of refrigeration cycle apparatus 100]
The refrigeration cycle apparatus 100 according to the first embodiment will be described. The refrigeration cycle apparatus 100 according to Embodiment 1 has a configuration corresponding to, for example, an air conditioner, a refrigerator, a refrigerator, a vending machine, a water heater, and the like.

The refrigeration cycle apparatus 100 includes a compressor 1 that compresses and discharges a sucked refrigerant, a refrigerant flow switching device 3 that switches a refrigerant flow path, a first heat exchanger 4 that functions as a condenser or an evaporator, and evaporation. A second heat exchanger 6 that functions as a condenser or a condenser, an expansion device 5 that decompresses the refrigerant, and an accumulator 7 that stores excess refrigerant.
In the first embodiment, the refrigerant main pipeline 2 is constituted by the refrigerant flow switching device 3, the first heat exchanger 4, the second heat exchanger 6, the expansion device 5, and the refrigerant pipes connecting them. .

The compressor 1 has a refrigerant discharge side connected to an oil separator 8, and a refrigerant suction side connected to an accumulator 7, and a first oil return part S1 and a second oil return part S2 described later. The compressor 1 can be comprised by the inverter compressor etc. which can control rotation speed, for example.
The refrigerant flow switching device 3 can be constituted by, for example, a four-way valve. Here, it is assumed that the first heat exchanger 4 is a heat source side heat exchanger mounted on an outdoor unit or the like, and the second heat exchanger 6 is a use side heat exchanger mounted on an indoor unit or the like. In this case, the refrigerant flow switching device 3 switches so as to connect the oil separator 8 and the second heat exchanger 6 and also connect the first heat exchanger 4 and the accumulator 7 during the heating operation. It is done. The refrigerant flow switching device 3 is switched so as to connect the oil separator 8 and the first heat exchanger 4 and also connect the second heat exchanger 6 and the accumulator 7 during the cooling operation.

The 1st heat exchanger 4 and the 2nd heat exchanger 6 are comprised by the fin tube type heat exchanger provided with the plate-shaped fin arrange | positioned in multiple parallel, and the heat exchanger tube connected to this fin, for example. be able to. One of the first heat exchangers 4 is connected to the refrigerant flow switching device 3 and the other is connected to one of the expansion devices 5. One of the second heat exchangers 6 is connected to the refrigerant flow switching device 3 and the other is connected to the other of the expansion device 5.
The expansion device 5 includes a mechanism for depressurizing the refrigerant, and can be configured by, for example, an expansion valve and a capillary tube. One of the expansion devices 5 is connected to the first heat exchanger 4 and the other is connected to the second heat exchanger 6.
The accumulator 7 stores surplus refrigerant in the refrigerant circuit of the refrigeration cycle apparatus 100. The accumulator 7 is connected to the first heat exchanger 4 or the second heat exchanger 6 via the refrigerant flow switching device 3 on the refrigerant inflow side, and is connected to the refrigerant suction side of the compressor 1 on the refrigerant outflow side.

The refrigeration cycle apparatus 100 is provided on the refrigerant discharge side of the compressor 1 and is connected to an oil separator 8 that separates the refrigerant and the refrigeration oil, and a first oil return portion S1 described later, and the first oil return portion. And an oil storage unit 12 for storing refrigeration oil supplied from the oil separator 8 via S1.
The oil storage unit 12 connects a storage container 12A for storing refrigeration oil, an upper part of the storage container 12A, and a first oil return part S1 described later, and extends from the upper part of the storage container 12A to the first oil return part S1. And a connecting pipe 11 formed so as to extend from the lower side to the upper side. In the storage container 12A, for example, the connection pipe 11 is connected to the upper part, and the connection pipe 13 is connected to the lower side surface.
The connection pipe 11 has an upper end connected to the oil return pipe 9 of the first oil return part S1, and a lower end connected to the storage container 12A. For example, the inner diameter of the connection pipe 11 may be set larger than that of the oil return pipe 9. Specifically, the inner diameter of the connecting pipe 11 is such that the surface tension acts as the refrigeration oil flows to the storage container 12A side and the refrigerant gas flows to the oil return pipe 9 side due to gravity in a state where there is no pressure difference between the upper end and the lower end. It is good to set it large so that becomes weak.
The connecting pipe 11 is formed so as to extend from the lower side to the upper side from the connecting position with the upper part of the storage container 12A to the connecting position with the oil return pipe 9, and the inner diameter thereof is also set large. Thereby, the refrigeration oil in the connection pipe 11 is easy to flow into the oil storage part 12 by the effect | action of a weight. In the oil reservoir 12, when the refrigerating machine oil in the storage container 12 </ b> A overflows, the refrigerating machine oil is stored in the connection pipe 11. For this reason, the connecting pipe 11 is a pipe-like member, but also fulfills the function of storing the refrigeration oil. For example, as shown in FIG. 1A2 (b), the connecting pipe 11 does not employ a configuration bent into a U shape. In the pipe line in the oil return pipe 9, the refrigerating machine oil flows not by the action of the pressure difference but by the action of gravity. For this reason, if it is a structure like FIG. 1A2 (b), refrigeration oil may be clogged. In order to avoid this, the connection pipe 11 of the refrigeration cycle apparatus 100 according to the first embodiment extends from the lower side to the upper side from the connection position with the upper part of the storage container 12A to the connection position with the oil return pipe 9. Is formed. Note that the connecting pipe 11 may be linear as shown in FIG. 1A2 (a), or a curved portion may be formed by meandering, for example.

The refrigeration cycle apparatus 100 includes a flow rate adjusting device 10 that adjusts the flow rate of the refrigeration oil, and is connected to the oil separator 8 and the compressor 1 on the suction side so that the refrigeration oil in the oil separator returns to the compressor 1. A first oil return portion S1 is provided. The flow rate adjusting device 10 of the first oil return portion S <b> 1 is connected to the oil return pipe 9. In the first embodiment, the first oil return portion S1 is configured to include the flow rate adjusting device 10. An oil return pipe 9 is connected to the first oil return portion S1.
The flow rate adjusting device 10 can be configured by a capillary tube, for example. The flow rate adjusting device 10 is provided on the downstream side of the connection position with the connection pipe 11 in the oil return pipe 9. That is, the flow rate adjusting device 10 is provided closer to the refrigerant suction side of the compressor 1 than the connection position of the oil return pipe 9 to the connection pipe 11.
The oil return pipe 9 is a pipe having one end connected to the oil separator 8 and the other end connected to the refrigerant suction side of the compressor 1 and the refrigerant outflow side of the accumulator 7. A connecting pipe 11 is connected in the middle of the oil return pipe 9. The return oil pipe 9 is provided with a flow rate adjusting device 10 so that the return amount of the refrigerating machine oil stored in the oil separator 8 is adjusted. The oil return pipe 9 has a connecting pipe 11 connected to the oil separator 8 side of the flow rate adjusting device 10.

The refrigeration cycle apparatus 100 includes a first opening / closing device 14 that is switched between open and closed, and one end is connected to the oil reservoir 12 and the other end is connected to the refrigerant suction side of the compressor 1 and stored in the oil reservoir 12. The refrigerating machine oil is returned to the compressor 1 with a second oil return section S2. The first opening / closing device 14 of the second oil return portion S2 is connected to the connecting pipe 13. In the first embodiment, the second oil return portion S2 includes the connecting pipe 13 and the first opening / closing device 14.
The first opening / closing device 14 can be constituted by, for example, an electromagnetic valve. The first opening / closing device 14 is opened when the compressor 1 is started.
The connection pipe 13 is a pipe having one end connected to the storage container 12 </ b> A and the other end connected to the refrigerant suction side of the compressor 1 and the refrigerant outflow side of the accumulator 7. The connection pipe 13 is connected to the storage container 12A of the oil storage part 12 so as to be positioned below the connection position between the storage container 12A of the oil storage part 12 and the first oil return part S1. That is, the connection position between the storage container 12A and the connection pipe 13 is lower than the connection position between the storage container 12A and the first oil return portion S1. In the refrigerant circuit of the refrigeration cycle apparatus 100, the other end of the oil return pipe 9, the other end of the connection pipe 13, and the refrigerant outflow side of the accumulator 7 are configured to merge on the refrigerant intake side of the compressor 1.

  The refrigeration cycle apparatus 100 includes a control device 25 that opens the first opening / closing device 14 when the compressor 1 is started. The control device 25 includes, for example, control of the rotational speed including operation and stop of the compressor 1, control of the opening degree of the expansion device 5, switching control of the refrigerant flow switching device 3, and the first switching device 14. And control of opening and closing of. Further, the control device 25 has a timekeeping function, for example, and can operate the compressor 1 at a preset timing or control the opening / closing of the first opening / closing device 14. ing.

[Starting timing of compressor 1]
FIG. 1G is an example of a control flowchart of the refrigeration cycle apparatus 100 according to the first embodiment. As shown in FIG. 1G, there are three conditions for controlling the refrigeration cycle apparatus 100 when the compressor 1 is started. FIG. 1G (a) shows Condition 1, FIG. 1G (b) shows Condition 2, and FIG. 1G (c) shows Condition 3.

First, a control flowchart according to condition 1 will be described with reference to FIG. 1G (a).
The control apparatus 25 starts the compressor 1 (step A1). The control device 25 determines whether or not a preset time X1 has elapsed (step A2). If it is determined that the preset time X1 has elapsed, the process proceeds to step A3. If it is determined that the preset time X1 has not elapsed, step A2 is repeated. The control device 25 opens the first opening / closing device 14 (step A3). The control device 25 determines whether or not a preset time X2 has elapsed (step A4). If it is determined that the preset time X2 has elapsed, the process proceeds to step A5. If it is determined that the preset time X2 has not elapsed, step A4 is repeated. The control device 25 closes the first opening / closing device 14 (step A5). The control device 25 performs a continuous operation described later (step A6). The control device 25 stops the compressor 1 (step A7).
As described above, in the control according to the condition 1, the compressor 1 is started, and the first opening / closing device 14 is opened after the preset time X1 has elapsed. This is because the refrigerating machine oil is likely to foam due to the vaporization of the refrigerant in the compressor 1 immediately after the compressor 1 is started, and the refrigerating machine oil tends to flow out.

Next, a control flowchart according to condition 2 will be described with reference to FIG. 1G (b).
The control apparatus 25 starts the compressor 1 (step B1). The control device 25 opens the first opening / closing device 14 (step B2). The control device 25 determines whether or not a preset time Y has elapsed (step B3). If it is determined that the preset time Y has elapsed, the process proceeds to step B4. If it is determined that the preset time Y has not elapsed, step B3 is repeated. The control device 25 closes the first opening / closing device 14 (step B4). The control device 25 performs continuous operation (step B5). The control device 25 stops the compressor 1 (step B6).
As described above, in the control according to condition 2, after the compressor 1 is started, the first opening / closing device 14 is opened without waiting for the preset time X1. In a state where the refrigerator oil is exhausted in the compressor 1, the amount of the refrigerator oil flowing out from the compressor 1 is small in the first place. Therefore, under the condition 2, in the state where the refrigerating machine oil is depleted, the first opening / closing device 14 is opened immediately after the compressor 1 is started, and the compressor 1 is lubricated.

Further, a control flowchart according to condition 3 will be described with reference to FIG. 1G (c).
The control device 25 opens the first opening / closing device 14 (step C1). The control device 25 determines whether or not a preset time Z1 has elapsed (step C2). If it is determined that the preset time Z1 has elapsed, the process proceeds to step C3. If it is determined that the preset time Z1 has not elapsed, step C2 is repeated. The control device 25 activates the compressor 1 (step C3). The control device 25 determines whether or not a preset time Z2 has elapsed (step C4). If it is determined that the preset time Z2 has elapsed, the process proceeds to step C5. If it is determined that the preset time Z2 has not elapsed, step C4 is repeated. The control device 25 closes the first opening / closing device 14 (step C5). The control device 25 performs a continuous operation described later (step C6). The control device 25 stops the compressor 1 (step C7).
As described above, in the control according to the condition 3, the order of starting the compressor 1 and opening the first opening / closing device 14 is reversed in the conditions 1 and 2. Certainly, if the compressor 1 is not started, the refrigerant does not circulate, so that the refrigeration oil is difficult to return to the compressor 1. However, actually, the residual pressure is generated in the refrigerant circuit even when the compressor 1 is stopped. For this reason, the refrigeration oil may be under pressure to return to the compressor 1. Therefore, under condition 3, the first opening / closing device 14 is opened before the compressor 1 is started, and the compressor 1 is lubricated.

The control device 25 opens the first opening / closing device 14 when starting the compressor 1. Here, the time condition when starting the compressor 1 is demonstrated.
(Condition 1) As shown in FIG. 1G (a), the control device 25 opens the first opening / closing device 14 after a preset time has elapsed since the compressor 1 was started. Note that the preset time X1 is set to a time until foaming of the oil surface due to vaporization of the refrigerant in the compressor 1 is settled (see step A2). Immediately after the compressor 1 is started, the liquid refrigerant inside the compressor 1 is vaporized, the oil surface is foamed, and the discharge amount of the refrigerating machine oil becomes very large. For this reason, even if the refrigerating machine oil is returned to the compressor 1 in a state where the oil surface is foamed, there is a possibility that the oil will come out immediately. Further, since the specific gravity of the refrigerating machine oil is smaller than that of the liquid refrigerant, the portion having a high oil concentration is likely to gather on the upper liquid surface (foaming side) in the compressor 1. Even if it returns, it will flow out of the compressor 1 immediately. Therefore, the control device 25 opens the first opening / closing device 14 after a preset time X1 has elapsed. Thereby, it can suppress that the returned refrigeration oil flows out of the compressor 1. FIG.

(Condition 2) As shown in FIG. 1G (b), the control device 25 opens the first opening / closing device 14 immediately after the compressor 1 is started, that is, when the compressor 1 is started.
In some cases, the compressor oil is depleted in the compressor 1, and as soon as possible, the dark refrigerator oil is returned to the compressor 1 to lubricate the compression mechanism. Therefore, the control device 25 may activate the first opening / closing device 14 together with the activation of the compressor 1. For example, condition 2 may be adopted in a situation where the refrigeration oil does not flow out of the compressor 1 as described in condition 1.

(Condition 3) As shown in FIG. 1G (c), the control device 25 opens the compressor 1 after a preset time has elapsed since the first opening / closing device 14 was opened.
In some cases, the compressor 1 has insufficient refrigerating machine oil required at the time of start-up, and before starting, it is desired to return the thick refrigerating machine oil to the compressor 1 and lubricate the compression mechanism. Therefore, the control device 25 may activate the first opening / closing device 14 before the compressor 1 is activated. For example, even when the compressor 1 is stopped, the residual pressure in the discharge side of the compressor 1 and the oil separator 8 is higher than the residual pressure on the suction side of the compressor 1, and the pressure difference and gravity Condition 3 may be adopted as long as the refrigeration cycle apparatus 100 can return oil into the compressor 1 from the oil reservoir 12 through the second oil return portion S2 by an action such as dropping.

[Description of operation of refrigeration cycle apparatus 100]
Next, the operation of the refrigeration cycle apparatus 100 will be described. Here, a case where the control device 25 operates under the condition 1 will be described as an example. That is, an operation when the first opening / closing device 14 is opened after a preset time has elapsed without opening the first opening / closing device 14 with the start of the compressor 1 will be described.

As shown in FIG. 1G (a), the control device 25 activates the compressor 1 and opens the first opening / closing device 14 for a preset time after a preset time has elapsed.
Here, the reason why the first opening / closing device 14 is opened after the compressor 1 is started and a preset time elapses is to prevent the reverse flow of the refrigerating machine oil. That is, when the compressor 1 is stopped or immediately after starting, the refrigerating machine oil flows backward due to the residual pressure, or conversely, due to the absence of a pressure difference, gravity drop becomes dominant and the flow direction of the refrigerating machine oil changes. Therefore, in order to prevent reverse flow of the refrigeration oil, the timing for opening the first opening / closing device 14 is delayed with respect to the timing for starting the compressor 1.
The first opening / closing device 14 is opened for a preset time in order to return the refrigeration oil stored in the oil storage unit 12 to the compressor 1.
The first opening / closing device 14 is opened for a preset time and then closed to store the refrigerating machine oil in the oil storage unit 12 again, and in the oil storage unit 12 and the second oil return unit S2. This is because a large amount of refrigerant flows to reduce the amount of refrigerant flowing in the refrigerant main pipeline 2 and prevent the performance of the refrigeration cycle apparatus 100 from deteriorating.

The control device 25 closes the first opening / closing device 14 during continuous operation and when stopped. Here, the time of continuous operation refers to the time when the operation of the compressor 1 is stabilized after a preset time has elapsed after the compressor 1 is started, not immediately after the compressor 1 is started.
During the continuous operation of the compressor 1, the refrigeration oil inside the compressor 1 is discharged together with the refrigerant gas, separated in the oil separator 8, and sequentially passed through the oil return pipe 9 and the suction side pipe of the compressor 1. Returned to 1 Thereby, it is suppressed that the refrigerating machine oil in the compressor 1 is exhausted.

The throttle of the flow rate adjusting device 10 is adjusted so that the amount of oil flowing per unit time is equal to or greater than the amount of oil separated per unit time in the oil separator 8 under all operating conditions assumed in the refrigeration cycle device 100. Is done. The flow rate adjusting device 10 is that the throttle is adjusted so that the oil separator 8 does not overflow with the separated oil. In addition, the above-mentioned operating conditions exclude the time of the rotation speed change of the compressor 1 including the time of starting.
In the flow rate adjusting device 10, not only the refrigerating machine oil but also part of the refrigerant gas flows through the oil return pipe 9. A part of the oil separated by the oil separator 8 enters the connection pipe 11 from the oil return pipe 9 and flows into the oil reservoir 12 due to gravity drop, so that the oil level is at the junction between the oil return pipe 9 and the connection pipe 11. Oil will accumulate until it reaches. Thereafter, oil does not accumulate in the oil reservoir 12, and the amount of oil separated by the oil separator 8 and the amount of oil flowing through the flow rate adjusting device 10 become equal.

  Even if the compressor 1 is stopped in this state, the oil is retained in the oil reservoir 12. Thereafter, when the first opening / closing device 14 is opened when the compressor 1 is started, the oil in the oil reservoir 12 is discharged from the connecting pipe 13 to the compressor 1 due to the pressure difference between the discharge side and the suction side of the compressor 1. It flows into the compressor 1 through the suction side pipe.

[Effects of refrigeration cycle apparatus 100 according to Embodiment 1]
The refrigeration cycle apparatus 100 according to the first embodiment has a configuration in which the refrigeration oil separated by the oil separator 8 flows from the oil separator 8 to the oil reservoir 12 and is stored by the oil reservoir 12. For this reason, even if it employ | adopts the structure which returns refrigerator oil when starting the compressor 1, it can suppress that the oil separation efficiency in the oil separator 8 will reduce. That is, it is possible to prevent the refrigerant gas in the oil separator 8 from flowing, the oil surface to wave and the refrigerating machine oil from scattering, and the refrigerating machine oil from flowing out of the oil separator 8 together with the refrigerant.
In addition, the refrigeration cycle apparatus 100 according to the first embodiment does not need to increase the size of the oil separator 8 in order to suppress the oil surface of the oil separator 8 from being swollen by the refrigerant gas, and is a major modification. Further, an increase in cost can be avoided. Furthermore, the refrigeration cycle apparatus 100 according to the first embodiment also suppresses an increase in the size of the outdoor unit on which the oil separator 8 is mounted, because the oil separator 8 does not need to be increased in size. be able to.

  The refrigeration cycle apparatus 100 according to the first embodiment closes the first opening / closing device 14 downstream of the oil storage unit 12 during continuous operation to store refrigeration oil in the oil storage unit 12, and first opens and closes during startup. The refrigerating machine oil stored by opening the apparatus 14 can be returned to the compressor 1. Accordingly, it is possible to suppress the exhaustion of the refrigerating machine oil of the compressor 1 when the compressor 1 is started, and to reduce the concentration of the refrigerating machine oil in the compressor 1 and to suppress poor lubrication of the compression mechanism unit.

  In the refrigeration cycle apparatus 100 according to the first embodiment, the liquid refrigerant accumulated while mixed with the refrigeration oil when the compressor 1 is stopped is rapidly vaporized and foamed when the compressor 1 is started, so that the refrigeration oil is Even if a large amount is discharged from the compressor 1, the refrigeration oil is immediately supplied from the suction side of the compressor 1, so that the lubrication failure of the compression mechanism portion due to the exhaustion of the refrigeration oil can be suppressed.

In addition, if a large amount of liquid refrigerant is accumulated in the compressor 1 when the compressor 1 is stopped, even if foaming due to vaporization of the refrigerant is suppressed at startup, the concentration of the refrigerating machine oil for a while until the refrigerant vaporizes. Therefore, the compressor 1 continues to be driven in a low state. For this reason, the compression mechanism part of the compressor 1 tends to be poorly lubricated. However, in the refrigeration cycle apparatus 100 according to the first embodiment, when the refrigeration cycle apparatus 100 is started, the refrigeration oil having a high concentration immediately flows into the compressor 1, so that the compression mechanism unit is prevented from being poorly lubricated. Can do.
The refrigeration cycle apparatus 100 according to the first embodiment can suppress poor lubrication even in the compressor 1 having a small amount of internal oil retention, and the compressor 1 can be downsized.

If the initial filling amount of the refrigerating machine oil is increased in order to prevent poor lubrication at the time of starting the compressor 1, the refrigerating machine oil is excessively accumulated in the compressor during continuous operation, and the motor (rotor) of the compressor 1 is accumulated. Even soaked in refrigerating machine oil, compression efficiency decreases.
However, the refrigeration cycle apparatus 100 according to the first embodiment employs a configuration that retains excess oil outside the compressor 1 during continuous operation. That is, during the continuous operation, since the first opening / closing device 14 is closed, the refrigerating machine oil is stored in the oil storage unit 12. Therefore, it is possible to suppress the amount of oil in the compressor 1 from becoming excessive and the performance such as the compression efficiency from being lowered.

  The refrigeration cycle apparatus 100 according to the first embodiment employs a configuration that retains excess oil outside the compressor 1 during continuous operation. For this reason, the oil level in the compressor 1 becomes higher during continuous operation, and the discharge amount of the refrigeration oil increases accordingly, and the refrigeration oil is carried to the first heat exchanger 4 and the like, and the heat exchange efficiency is reduced. This can be suppressed.

Inside the oil separator, when the compressor is stopped, liquid refrigerant stored in the oil separator is collected and may be mixed with refrigerating machine oil. This is because the interface between the refrigerating machine oil and the refrigerant is large, and is caused by the surface tension and the compatibility between the refrigerant and the refrigerating machine oil. Thus, in the state of poor oil separation in which liquid refrigerant and refrigerating machine oil are mixed, the liquid refrigerant and refrigerating machine oil may be filled up to the refrigerant outlet of the oil separator. If it does so, when starting a compressor, the refrigerating machine oil in an oil separator may flow out with a refrigerant.
In the refrigeration cycle apparatus 100 according to Embodiment 1, the inner diameter of the connecting pipe 11 of the oil reservoir 12 is set to be large so that the effect of the surface tension of the refrigeration machine oil is weakened. For this reason, only the refrigerating machine oil is easy to flow into the storage container 12 </ b> A through the connection pipe 11. Therefore, the refrigeration cycle apparatus 100 according to the first embodiment can suppress the refrigerant from entering the storage container 12A and suppress the oil separation failure.

  The refrigerant main pipeline 2 has various configurations in accordance with the purpose of use of the refrigeration cycle apparatus. However, the refrigerant main pipeline 2 is not limited to the aspect of the first embodiment, and the refrigeration cycle apparatus 100 according to the first embodiment Similar effects can be obtained.

  An accumulator 7 is connected between the refrigerant main pipeline 2 and the suction side of the compressor 1. Even when this accumulator 7 is not installed, the same effect as that of the refrigeration cycle apparatus 100 according to Embodiment 1 can be obtained.

  In the first embodiment, the case where the flow rate adjusting device 10 is a capillary will be described as an example, but the present invention is not limited thereto. For example, the flow rate adjusting device 10 can obtain the same effect as the refrigeration cycle device 100 according to the first embodiment, even if the flow rate adjusting device 10 is configured with a flow rate adjusting valve whose opening degree can be changed. In addition, when using a flow control valve, when the opening degree is adjusted so that a part of the refrigerant gas flows along with the oil in the oil return pipe 9 at least while the oil is stored in the oil reservoir 12 during continuous operation. Good.

  The 1st heat exchanger 4 and the 2nd heat exchanger 6 are not limited to comprising with a single heat exchanger. For example, the first heat exchanger 4 and the second heat exchanger 6 employ a configuration in which a plurality of heat exchangers are connected in parallel, a configuration in which the heat exchangers are connected in series, or a configuration in which a combination of parallel and series is connected. Even so, the same effects as those of the refrigeration cycle apparatus 100 according to Embodiment 1 can be obtained.

  Although not shown in FIG. 1, the refrigeration cycle apparatus 100 may adopt, for example, a mode in which a gas-liquid separator and a bypass pipe are provided, or each pipe is provided with an on-off valve and a flow control valve. The embodiment may be adopted. Further, the refrigeration cycle apparatus 100 may be an aspect in which the refrigerant flow switching device 3 is not provided. Even if it is these aspects, the effect similar to the refrigerating-cycle apparatus 100 which concerns on this Embodiment 1 can be acquired.

[Variation 1 of Embodiment 1]
FIG. 1B is Modification 1 (refrigeration cycle apparatus 101) of the refrigeration cycle apparatus 100 according to Embodiment 1. Constituent elements having the same functions and operations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 1B, the refrigeration cycle apparatus 101 includes a second opening / closing device 17 provided in the connection pipe 11. The second opening / closing device 17 can be constituted by an electromagnetic valve, for example.

FIG. 1H is an example of a control flowchart of the refrigeration cycle apparatus 101 according to the first embodiment. With reference to FIG. 1H, the operation of the refrigeration cycle apparatus 101 according to the first modification of the first embodiment will be described. The refrigeration cycle apparatus 101 also executes the control according to the conditions 1 to 3 (FIGS. 1H (a) to 1H (c)) corresponding to the conditions 1 to 3 of the control of the refrigeration cycle apparatus 100.
Differences between FIGS. 1G (a) to 1G (c) and FIGS. 1H (a) to 1H (c) are as follows. As shown in FIG. 1H, each condition of the control flowchart of the refrigeration cycle apparatus 101 is different from FIG. 1G in that an opening / closing control step of the second opening / closing device 17 is added. Specifically, in FIG. 1H (a), a step of opening the second switchgear 17 (step A14) and a step of closing the second switchgear 17 (step A19) are added. Others are the same as FIG. 1G (a). Similarly in FIG. 1H (b) and FIG. 1H (c), Step B13, Step B18, Step C12, and Step C19 are added.

As shown in FIG. 1H, the first opening / closing device 14 operates in the same manner as in the first embodiment. In the first modification including the second opening / closing device 17, the control device 25 is the same as the case shown in the condition 1 of the first embodiment, after a preset time immediately after the start of the compressor 1 has elapsed. The first opening / closing device 14 and the second opening / closing device 17 are opened.
Alternatively, in the same case as shown in the condition 2 of the first embodiment, the first opening / closing device 14 and the second opening / closing device 17 are opened immediately after the compressor 1 is started, that is, when the compressor 1 is started.
Alternatively, in a case similar to the case shown in the condition 3 of the first embodiment, after a preset time immediately after the first opening / closing device 14 and the second opening / closing device 17 are opened, the compressor 1 Start up. Note that the second opening / closing device 17 may be opened before opening the first opening / closing device 14.
As a result, the discharge pressure is first applied to the oil reservoir 12 so that the pressure is higher than the suction side of the compressor 1, and the reverse flow of the refrigerating machine oil can be prevented.

  Further, the control device 25 opens the second opening / closing device 17 during the continuous operation of the compressor 1. More specifically, the control device 25 activates the compressor 1 to open the first opening / closing device 14 and the second opening / closing device 17, and then closes the first opening / closing device 14.

  Further, the control device 25 closes the second opening / closing device 17 when the compressor 1 is stopped.

  By adopting the configuration of the first modification, the refrigerating machine oil in the oil reservoir 12 is maintained at a high concentration with respect to the refrigerant when the compressor 1 is stopped. That is, the refrigerating machine oil in the compressor 1 can be kept at a high concentration without the refrigerating machine oil in the oil reservoir 12 being diluted by the refrigerant. Therefore, in the refrigeration cycle apparatus 101 according to the first modification, it is possible to more reliably suppress poor lubrication of the compressor 1.

[Modification 2 of Embodiment 1]
FIG. 1C is Modification 2 (refrigeration cycle apparatus 102) of the refrigeration cycle apparatus 100 according to Embodiment 1. Constituent elements having the same functions and operations as those of the first embodiment and the first modification of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
The refrigeration cycle apparatus 102 according to the modified example 2 includes an accumulator connection pipe 20 having one end connected to the oil separator 8 side of the oil return pipe 9 relative to the connection position of the connection pipe 11 and the other end connected to the accumulator 7. ing. The accumulator connection pipe 20 is provided with a third opening / closing device 21 that is opened when the compressor 1 is started. The accumulator 7 is connected to the suction side of the compressor 1 together with the first oil return portion S1 and the second oil return portion S2.

  Although different from the mode of FIG. 1C, the accumulator connection pipe 20 may be not only configured to be directly connected to the accumulator 7 but also a mode of connecting the accumulator 7 and the refrigerant main pipeline 2.

FIG. 1I is an example of a control flowchart of the refrigeration cycle apparatus 102 according to the first embodiment. With reference to FIG. 1I, the operation of the refrigeration cycle apparatus 101 according to the second modification of the first embodiment will be described. The refrigeration cycle apparatus 102 executes control related to condition 1 (FIG. 1I) corresponding to condition 1 of control of the refrigeration cycle apparatus 100.
Differences between FIG. 1G (a) and FIG. 1I are as follows. As shown in FIG. 1I, in the control flowchart of the refrigeration cycle apparatus 102, an opening / closing control step for the second opening / closing device 17 in FIG. 1H and an opening / closing control step for the third opening / closing device 21 are added. It differs from FIG. 1G.
Specifically, in FIG. 1I, the step of opening the second switchgear 17 (step D5), the step of closing the second switchgear 17 (step D11), and the step of opening the third switchgear 21 (step) D2) and a step of closing the third opening / closing device 21 (step D6) are added. Others are the same as FIG. 1G (a).

  As shown in FIG. 1I, when the compressor 1 is started, the control device 25 opens the third opening / closing device 21 and then opens the first opening / closing device 14 and the second opening / closing device 17. 3 is closed. As a result, the liquid refrigerant accumulated in the oil separator 8 passes through the connecting pipe 11, the oil reservoir 12, and the connecting pipe 13 in order, and temporarily accumulates in the accumulator 7. Although it is the timing at which the third opening / closing device 21 is opened, it may be the same as the start of the compressor 1 or just before the start or just after the start. Although it is a timing which closes the 3rd switchgear 21, it is good also as the 3rd switchgear 21 being closed immediately after opening the 1st switchgear 14 and the 2nd switchgear 17, for example.

  During continuous operation of the compressor 1, the operation is as follows. When the compressor 1 is started, the control device 25 opens the first opening / closing device 14 and the second opening / closing device 17 and closes the third opening / closing device 21. In addition to this during the continuous operation, the control device 25 closes the first opening / closing device 14. Thereby, refrigerating machine oil can be prevented from flowing into the accumulator 7 from the accumulator connecting pipe 20.

  When the compressor 1 is stopped, the operation is as follows. The control device 25 closes the second opening / closing device 17 and the third opening / closing device 21 when the compressor 1 is stopped. As a result, the liquid refrigerant accumulated in the oil separator 8 when the compressor 1 is stopped is prevented from returning to the compressor 1 through the connecting pipe 11, the oil reservoir 12 and the connecting pipe 13 in order. The liquid refrigerant accumulated in the oil separator 8 at the time of stopping can be stored in the accumulator 7. Thereby, when the compressor 1 is started, it can suppress more reliably that the oil concentration in the compressor 1 becomes low and the compressor 1 becomes poor lubrication.

[Modification 3 of Embodiment 1]
FIG. 1D is Modification 3 (refrigeration cycle apparatus 103) of the refrigeration cycle apparatus 100 according to Embodiment 1. Constituent elements having the same functions and operations as those of the first embodiment and the first and second modifications of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
In the third modification, in addition to the configuration of the second modification, the discharge pipe 1 </ b> A connecting the compressor 1 to the oil separator 8 is brought into contact with the oil storage section 12 while being in contact with it. That is, the refrigeration cycle apparatus 103 further includes a discharge pipe 1 </ b> A that connects the discharge side of the compressor 1 and the oil separator 8. And 1 A of discharge pipes are formed so that the outer peripheral surface of the oil storage part 12 (storage container 12A) may be contacted.

Next, the operation of the third modification of the first embodiment will be described. During continuous operation, the temperature in the oil reservoir 12 decreases due to heat dissipation due to a temperature difference from the outside air. When the refrigerant and the refrigerating machine oil are compatible, the refrigerant gas is more easily dissolved in the refrigerating machine oil at a lower temperature and a higher pressure. Regardless of compatibility, the refrigerant is liable to be liquefied and mixed with the refrigerating machine oil when the temperature becomes equal to or lower than the saturated vapor temperature. Therefore, when the temperature of the oil reservoir 12 is lowered, the concentration of the refrigerating machine oil in the oil reservoir 12 is lowered.
In the configuration of the modified example 3, since heat is supplied from the discharge pipe 1A through which the high-temperature refrigerant flows to the oil storage unit 12, the temperature decrease of the refrigeration oil in the oil storage unit 12 is suppressed, and the oil in the oil storage unit 12 The concentration of becomes higher. When the compressor 1 is stopped with the first opening / closing device 14 and the second opening / closing device 17 closed, the concentration of oil in the oil reservoir 12 remains high until the next startup. Thereby, when the compressor 1 is started, it can suppress more reliably that the oil concentration in the compressor 1 becomes low and the compressor 1 becomes poor lubrication.

[Modification 4 of Embodiment 1]
FIG. 1E is Modification 4 (refrigeration cycle apparatus 104) of the refrigeration cycle apparatus 100 according to Embodiment 1. Constituent elements having the same functions and operations as those of the first embodiment and the first to third modifications of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
In the configuration of the modified example 4, in addition to the configuration of the modified example 2, a heater 23 for heating the oil storage unit 12 is provided. That is, the refrigeration cycle apparatus 104 includes a heater 23 that heats the inside of the oil storage unit 12. The controller 25 drives the heater 23 and opens the second opening / closing device 17 before starting the compressor 1.

FIG. 1J is an example of a control flowchart of the refrigeration cycle apparatus 104 according to the first embodiment. With reference to FIG. 1J, operation | movement of the modification 4 of this Embodiment 1 is demonstrated. The refrigeration cycle apparatus 104 executes control according to the conditions 1 to 3 (FIG. 1J (a) to FIG. 1J (c)) corresponding to the conditions 1 to 3 of the control of the refrigeration cycle apparatus 100.
Differences between FIGS. 1G (a) to 1G (c) and FIGS. 1J (a) to 1J (c) are as follows. As shown in FIG. 1J, each condition of the control flowchart of the refrigeration cycle apparatus 104 includes a step of opening / closing control of the second opening / closing device 17 and a step of starting and stopping the heater 23. This is different from FIG. 1G. Specifically, in FIG. 1J (a), the step of opening the second switching device 17 (step A21), the step of closing the second switching device 17 (step A31), and the step of starting the heater 23 (step) A22) and a step of stopping the heater 23 (step A23) are added. Others are the same as FIG. 1G (a). Similarly in FIG. 1J (b) and FIG. 1J (c), Step B21 to Step B23 and Step B30, and Step C21 to Step C24 and Step C31 are added.

  As shown in FIG. 1J, while the compressor 1 is stopped, the heater 23 is driven and the second opening / closing device 17 is opened before the compressor 1 is started. The temperature in the oil reservoir 12 rises, and the gas refrigerant dissolved in the refrigerating machine oil flows out through the second opening / closing device 17. In addition, the refrigerant that has dissolved in the oil reservoir 12 as a liquid refrigerant is also gasified and flows out through the second opening / closing device 17. As described above, since the refrigerant is removed from the oil reservoir 12, the oil concentration in the oil reservoir 12 is increased accordingly. For example, the control device 25 stops the heater 23 before the compressor 1 is started. Thereby, when the compressor 1 is started, it can suppress more reliably that the oil concentration in the compressor 1 becomes low and the compressor 1 becomes poor lubrication.

[Modification 5 of Embodiment 1]
FIG. 1F is a fifth modification of the refrigeration cycle apparatus 100 according to the first embodiment. The refrigeration cycle apparatus according to Modification 5 includes an oil holding tube 24 instead of the oil storage unit 12.
The oil holding pipe 24 includes a pipe formed in a spiral shape. The oil holding pipe 24 is constituted by a pipe having a large inner diameter so that, for example, a refrigerating machine oil can be stored in a preset amount. As shown in FIG. 1F, the oil holding pipe 24 has one end connected to the oil return pipe 9 and the other end connected to the connecting pipe 13. As described in connection pipe 11, oil holding pipe 24 is a pipe line without a rising portion from one end to the other end. With this configuration, oil can be stored in the oil holding pipe 24 during continuous operation, and thus the same effect as that of the oil storage unit 12 can be obtained. Moreover, since it can be made into a free shape and arrangement | positioning compared with the case of the oil storage part 12, if it is a pipe line without a raise part from one edge part to the edge part connected to the connection pipe 13, a refrigeration cycle apparatus is made small Can be

Embodiment 2. FIG.
FIG. 2A shows a schematic configuration diagram of a refrigeration cycle apparatus 200 according to the second embodiment. Constituent elements having the same functions and operations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
In the second embodiment, the connecting pipe 11 is not provided. The oil storage unit 12 includes a storage container 12A that stores refrigeration oil, and the connection pipe 11 is not provided. That is, in the second embodiment, the refrigerating machine oil storage section is the storage container 12A.
Further, instead of the oil return pipe 9 described in the first embodiment, an upstream oil return pipe 15 and a downstream oil return pipe 16 are provided. That is, the refrigeration cycle apparatus 200 includes an upstream oil return pipe 15 that connects the oil separator 8 and the storage container 12A. Further, the first oil return portion S1 is provided with a flow rate adjusting device 10 and includes a downstream oil return pipe 16 that connects the storage container 12A and the suction side of the compressor 1.

  For example, an upstream oil return pipe 15 and a downstream oil return pipe 16 are connected to the oil reservoir 12 at the upper part of the storage container 12A. In the second embodiment, in the storage container 12A, the connection height position of the upstream oil return pipe 15 and the connection height position of the downstream oil return pipe 16 are the same or the connection height of the upstream oil return pipe 15 The height should be higher.

[Description of operation of refrigeration cycle apparatus 200]
FIG. 2E is an example of a control flowchart of the refrigeration cycle apparatus 200 according to the second embodiment. FIG. 2E is the same as the control flowchart described in FIG. 1F. With reference to FIG. 2E, the operation of the refrigeration cycle apparatus 200 will be described.
As in the first embodiment, when the compressor 1 is started, the first opening / closing device 14 is opened. Here, the case where the control device 25 adopts the condition 1 will be described as an example. As shown in FIG. 2E (a), the first opening / closing device 14 is opened for a preset time, and the first opening / closing device 14 is closed during continuous operation and when stopped. During the continuous operation of the compressor 1, the refrigeration oil inside the compressor 1 is discharged together with the refrigerant gas and separated in the oil separator 8, and the upstream oil return pipe 15, the oil reservoir 12 and the downstream oil return pipe 16 are sequentially arranged. It flows and returns to the compressor 1 from the pipe on the suction side of the compressor 1.

At this time, not only the refrigerating machine oil but also a part of the refrigerant gas flows through the upstream side oil return pipe 15, the oil reservoir 12, and the downstream side oil return pipe 16 through the flow rate adjusting device 10 whose throttle is adjusted. . Thereby, it can avoid that the inside of the oil separator 8 overflows with the separated refrigerating machine oil.
Further, a part of the refrigerating machine oil that has flowed into the oil reservoir 12 from the upstream oil return pipe 15 is accumulated until the oil level reaches the joint of the downstream oil return pipe 16 due to gravity drop.

Thereafter, the oil does not accumulate in the oil reservoir 12 and the amount of oil flowing through the upstream oil return pipe 15 and the downstream oil return pipe 16 becomes equal. Even if the compressor 1 is stopped in this state, the oil is retained in the oil reservoir 12.
Thereafter, when the first opening / closing device 14 is opened when the compressor 1 is started, the oil in the oil reservoir 12 is discharged from the connecting pipe 13 to the compressor 1 due to the pressure difference between the discharge side and the suction side of the compressor 1. It flows into the compressor 1 through the suction side pipe.
When a flow rate control valve is used instead of the flow rate adjusting device 10, at least the upstream oil return pipe 15, the oil storage unit 12, and the downstream side return pipe are stored while the refrigeration oil is stored in the oil storage unit 12 during continuous operation. The opening degree is adjusted so that a part of the refrigerant gas flows in the oil pipe 16 together with the refrigerating machine oil.

[Effect of refrigeration cycle apparatus 200 according to Embodiment 2]
The refrigeration cycle apparatus 200 according to the second embodiment can obtain the same effects as the refrigeration cycle apparatus 100 according to the first embodiment.

[Modification 1 of Embodiment 2]
FIG. 2B is Modification 1 (refrigeration cycle apparatus 201) of the refrigeration cycle apparatus 200 according to Embodiment 2. The first modification has a configuration similar to the first modification of the first embodiment.
The refrigeration cycle apparatus 201 further includes a second opening / closing device 18 and a fourth opening / closing device 19 provided in each of the upstream oil return pipe 15 and the downstream oil return pipe 16 and opened when the compressor 1 is started. The upstream oil return pipe 15 is provided with a second opening / closing device 18, and the downstream oil return pipe 16 is provided with a fourth opening / closing device 19. The second opening / closing device 18 and the fourth opening / closing device 19 can be constituted by electromagnetic valves, for example. The second opening / closing device 18 and the fourth opening / closing device 19 have a configuration corresponding to the second opening / closing device 17 described in the first embodiment.

FIG. 2F is an example of a control flowchart of the refrigeration cycle apparatus 201 according to the second embodiment. With reference to FIG. 2F, operation | movement of the refrigerating-cycle apparatus 200 which concerns on the modification 1 of this Embodiment 2 is demonstrated. The refrigeration cycle apparatus 200 executes control according to the conditions 1 to 3 (FIGS. 2E (a) to 2E (c)) corresponding to the conditions 1 to 3 of the refrigeration cycle apparatus 100. And the refrigeration cycle apparatus 201 which concerns on this modification 1 performs the control which concerns on the conditions 1-condition 3 (FIG. 2F (a)-FIG. 2 F (c)) corresponding to the conditions 1-condition 3 of the refrigeration cycle apparatus 200. FIG. Run.
Differences between FIGS. 2E (a) to 2E (c) and FIGS. 2F (a) to 2F (c) are as follows. As shown in FIG. 2F, an opening / closing control step of the second opening / closing device 18 and an opening / closing control step of the fourth opening / closing device 19 are added to each condition of the control flowchart of the refrigeration cycle device 201. This is different from FIG. 2E. Specifically, in FIG. 2F (a), the step of opening the second opening / closing device 18 (step A53), the step of closing the second opening / closing device 18 (step A60), and the opening of the fourth opening / closing device 19 are performed. A step (step A56) and a step (step A61) for closing the fourth opening / closing device 19 are added. Others are the same as FIG. 2E (a). Similarly in FIG. 2F (b) and FIG. 2F (c), Step B52, Step B55, Step B59, and Step B60, and Step C51, Step C56, Step C60, and Step C61 are added.

As shown in FIG. 2F, in the first modification of the second embodiment including the second opening / closing device 18 and the fourth opening / closing device 19, the control device 25 is set in advance after starting the compressor 1. After the elapse of time, the first opening / closing device 14 and the second opening / closing device 18 are opened. Alternatively, immediately after the compressor 1 is started, that is, when the compressor 1 is started, the first opening / closing device 14 and the second opening / closing device 18 are opened. Alternatively, the compressor 1 is started after a preset time immediately after the first opening / closing device 14 and the second opening / closing device 18 are opened. In addition, when starting the compressor 1, there is no designation | designated about opening / closing of the 4th opening / closing apparatus 19. FIG.
Note that the second opening / closing device 18 may be opened before opening the first opening / closing device 14. As a result, the discharge pressure is first applied to the oil reservoir 12 so that the pressure is higher than the suction side of the compressor 1, and the reverse flow of the refrigerating machine oil can be prevented.

  The control device 25 opens the second switching device 18 and the fourth switching device 19 during continuous operation.

  The control device 25 closes the second opening / closing device 18 and the fourth opening / closing device 19 when stopped.

  When the compressor 1 is started, there is no designation for opening / closing the fourth opening / closing device 19, but the fourth opening / closing is performed before the first opening / closing device 14 is closed when shifting to continuous operation. The device 19 is opened. Thereby, it avoids that both the 1st opening / closing device 14 and the 4th opening / closing device 19 will be in the closed state, and in any of 1st oil return part S1 and 2nd oil return part S2, It can be avoided that the refrigerating machine oil stops flowing and the refrigerating machine oil is accumulated in the oil reservoir 12 and the oil separator 8.

When the compressor 1 is stopped, the refrigerant gas in the oil reservoir 12 is liquefied or dissolved in the stored refrigeration oil. The gasification and liquefaction of the refrigerant when the compressor 1 is stopped can occur anywhere, for example, the wall of a pipe. Depending on the environment in which the refrigeration cycle apparatus 100 is installed, the temperature of the oil storage unit 12 changes day and night. If a temperature change occurs on the wall surface of the oil reservoir 12 and the temperature of the wall surface decreases, the refrigerant gas liquefies on the wall surface. The liquid refrigerant tends to be bundled so that the interfacial energy becomes small due to the surface tension. For this reason, if the refrigerant flows into the oil reservoir 12 when the compressor 1 is stopped, the liquefied refrigerant may accumulate in the oil reservoir 12.
A second opening / closing device 18 and a fourth opening / closing device 19 are connected to the oil reservoir 12 of the first modification according to the second embodiment, and these are closed when the compressor 1 is stopped. For this reason, it has the effect that the liquefied refrigerant does not accumulate in the oil reservoir 12.

[Modification 2 of Embodiment 2]
FIG. 2C is a second modification (refrigeration cycle apparatus 202) of the refrigeration cycle apparatus 200 according to Embodiment 2. The second modification has a configuration similar to the second modification of the first embodiment.
The refrigeration cycle apparatus 202 includes an accumulator 7 connected to the suction side of the compressor 1 together with the first oil return portion S1 and the second oil return portion, and a second opening / closing device 18 of the upstream oil return pipe 15 at one end. And an accumulator connecting pipe 20 connected to the accumulator 7 at the other end. The accumulator connecting pipe 20 is provided with a third opening / closing device 21 that is opened when the compressor 1 is started.

FIG. 2G is an example of a control flowchart of the refrigeration cycle apparatus 202 according to the second embodiment. With reference to FIG. 2G, operation | movement of the refrigerating-cycle apparatus 200 which concerns on the modification 2 of this Embodiment 2 is demonstrated. The refrigeration cycle apparatus 202 executes control related to condition 1 (FIG. 2G) corresponding to condition 1 of control of the refrigeration cycle apparatus 200.
Differences between FIG. 2E (a) and FIG. 2G are as follows. As shown in FIG. 2G, the control flow chart of the refrigeration cycle apparatus 202 includes steps for opening / closing control of the second opening / closing device 18, steps for opening / closing control of the fourth opening / closing device 19, and opening / closing of the third opening / closing device 21. It is different from FIG. 2E (a) in that a control step is added.
Specifically, in FIG. 2G, the step of opening the second switching device 18 (step D14), the step of closing the second switching device 18 (step D22), and the step of opening the fourth switching device 19 (step) D18), a step of closing the fourth switchgear 19 (step D23), a step of opening the third switchgear 21 (step D12), and a step of closing the third switchgear 21 (step D16) are added. Has been. Others are the same as FIG. 2E (a).

  As shown in FIG. 2G, when the compressor 1 is started, the control device 25 opens the third switching device 21 and then opens the first switching device 14 and the second switching device 18, and then 3 is closed. As a result, the liquid refrigerant accumulated in the oil separator 8 passes through the connecting pipe 11, the oil reservoir 12, and the connecting pipe 13 in order, and temporarily accumulates in the accumulator 7. In addition, although it is the timing which opens the 3rd opening / closing apparatus 21, it is good also as the start of the compressor 1, or just before starting or just after starting. Although it is a timing which closes the 3rd switchgear 21, it is good also as the 3rd switchgear 21 being closed immediately after opening the 1st switchgear 14 and the 2nd switchgear 18, for example.

  During continuous operation of the compressor 1, the operation is as follows. When starting up the compressor 1, the control device 25 opens the first opening / closing device 14 and the second opening / closing device 18, and closes the third opening / closing device 21. In addition to this during the continuous operation, the control device 25 closes the first opening / closing device 14. Thereby, refrigerating machine oil can be prevented from flowing into the accumulator 7 from the accumulator connecting pipe 20.

  When the compressor 1 is stopped, the operation is as follows. The control device 25 closes the second opening / closing device 18, the fourth opening / closing device 19, and the third opening / closing device 21 when the compressor 1 is stopped. As a result, the liquid refrigerant accumulated in the oil separator 8 when the compressor 1 is stopped is prevented from returning to the compressor 1 through the connecting pipe 11, the oil reservoir 12 and the connecting pipe 13 in order. The liquid refrigerant accumulated in the oil separator 8 at the time of stopping can be stored in the accumulator 7. Thereby, when the compressor 1 is started, it can suppress more reliably that the oil concentration in the compressor 1 becomes low and the compressor 1 becomes poor lubrication.

[Modification 3 of Embodiment 2]
FIG. 2D is a third modification of the refrigeration cycle apparatus 200 according to the second embodiment. The third modification has a configuration similar to the fifth modification of the first embodiment.
In the refrigeration cycle apparatus according to the third modification of the second embodiment, an oil holding pipe 24 is provided instead of the oil reservoir 12. As shown in FIG. 2D, the oil holding pipe 24 connects one end to the upstream oil return pipe 15 and the downstream oil return pipe 16 and connects the other end to the connection pipe 13. Others are the same as in the fifth modification of the first embodiment.

  With this configuration, oil can be stored in the oil holding pipe 24 during continuous operation, and thus the same effect as that of the oil storage unit 12 can be obtained. Moreover, since it can be made into a free shape and arrangement | positioning compared with the case of the oil storage part 12, if it is a pipe line without a raise part from one edge part to the edge part connected to the connection pipe 13, a refrigeration cycle apparatus is small-sized. Can be

[Other aspects]
The aspects of Modification 3 and Modification 4 according to Embodiment 1 can also be applied to Embodiment 2. That is, the configuration described in the third modification of the first embodiment, in which the discharge pipe 1A connecting the compressor 1 to the oil separator 8 is brought into contact with the periphery of the oil reservoir 12, is also applied to the second embodiment. be able to. The configuration provided with the heater 23 for heating the oil reservoir 12 described in the fourth modification of the first embodiment can also be applied to the second embodiment.

In addition, when combining the heater 23 of the modification 4 of Embodiment 1 with the aspect of the refrigerant circuit of FIG. 2C of Embodiment 2, it is good to control the 2nd switchgear 18 etc. as follows. That is, when the heater 23 is activated, the second opening / closing device 18 may be opened, and the third opening / closing device 21 and the fourth opening / closing device 19 may be closed.
If the fourth opening / closing device 19 is left open, the pressure of the oil reservoir 12 increases due to the refrigerant being vaporized by being heated by the heater 23, and not only the gas refrigerant from the second oil return section S2. Refrigerator oil and liquid refrigerant may flow to the suction side of the compressor 1 in some cases. The main purpose of the heater 23 is to let out the gas refrigerant dissolved in the refrigerating machine oil.
Further, if the fourth opening / closing device 19 is left open before being heated by the heater 23, the refrigerant may flow backward from the compressor 1 side to the oil storage unit 12 side.

  FIG. 2H is an example of a control flowchart in the case where the fourth modification of the first embodiment is combined with the second embodiment. This flowchart corresponds to FIG. 1J. Differences between FIGS. 2E (a) to 2E (c) and FIGS. 2H (a) to 2H (c) are as follows. As shown in FIG. 2H, each condition of the control flowchart includes an opening / closing control step of the second opening / closing device 18, an opening / closing control step of the fourth opening / closing device 19, and a start / stop control of the heater 23. It is different from FIG. 2E in that a step is added. Specifically, in FIG. 2H (a), the opening step of the second opening / closing device 18 (step A71), the step of closing the second opening / closing device 18 (step A82), and the fourth opening / closing device 19 are opened. A step (Step A78), a step of closing the fourth opening / closing device 19 (Step A83), a step of starting the heater 23 (Step A72), a step of stopping the heater 23, and (Step A73) are added. ing. Others are the same as FIG. 2E (a). Similarly in FIG. 2H (b) and FIG. 2H (c), Step B71 to Step B73, Step B81 and Step B82, and Step C71 to Step C73, Step C78, Step C82 and Step C83 are added. .

  DESCRIPTION OF SYMBOLS 1 Compressor, 1A discharge pipe, 2 Refrigerant main pipe line, 3 Refrigerant flow path switching device, 4 1st heat exchanger, 5 expansion device, 6 2nd heat exchanger, 7 Accumulator, 8 Oil separator, 9 Oil return pipe, DESCRIPTION OF SYMBOLS 10 Flow control apparatus, 11 Connection pipe, 12 Oil storage part, 12A Storage container, 13 Connection pipe, 14 1st switchgear, 15 Upstream oil return pipe, 16 Downstream oil return pipe, 17 2nd switchgear, 18 2 switchgears, 19 4th switchgear, 20 accumulator connecting pipe, 21 3rd switchgear, 23 heater, 24 oil holding pipe, 25 control device, 100 refrigeration cycle apparatus, 101 refrigeration cycle apparatus, 102 refrigeration cycle apparatus , 103 refrigeration cycle apparatus, 104 refrigeration cycle apparatus, 200 refrigeration cycle apparatus, 201 refrigeration cycle apparatus, 202 refrigeration cycle apparatus, S1 first return Oil part, S2 Second oil return part.

Claims (14)

In a refrigeration cycle apparatus including a refrigerant circuit including a compressor, a condenser, a throttle device, and an evaporator,
An oil separator provided on the refrigerant discharge side of the compressor, for separating the refrigerant and the refrigerating machine oil;
An oil reservoir connected to the oil separator and storing refrigerating machine oil;
Includes a flow control device for regulating the flow rate of refrigerating machine oil, the first oil return portion of the overflow oil from the oil reservoir is connected to the suction side of the oil reservoir and the compressor back to the compressor When,
Including a first opening / closing device that is switched between open and closed, and connected to the oil reservoir so that one end is located below a connection position between the first oil return portion and the oil reservoir, and the other end is the A second oil return unit connected to the refrigerant suction side of the compressor and returning the refrigeration oil stored in the oil storage unit to the compressor;
An oil return pipe connecting the oil separator and the oil reservoir;
An accumulator connected to the suction side of the compressor together with the first oil return part and the second oil return part;
An accumulator connecting pipe connected to the accumulator;
A control device that opens the first opening and closing device when starting the compressor, and closes the first opening and closing device after returning the refrigeration oil stored in the oil reservoir to the compressor;
With
The oil reservoir is
A storage container for storing refrigerating machine oil;
One end is connected to the upper part of the storage container, the other end is connected to the oil return pipe and the first oil return part, and extends from the lower side to the upper side from the upper part of the storage container to the first oil return part. A connecting pipe formed as follows,
One end of the accumulator connection pipe is connected to the oil separator side of the oil return pipe from the connection position between the connection pipe and the first oil return portion, and the other end of the accumulator connection pipe is connected to the accumulator. Connected to
The accumulator connecting pipe is provided with a third opening / closing device,
The control device opens the third opening / closing device when starting the compressor. The refrigeration cycle apparatus according to claim 1, wherein the connection pipe is provided with a second opening / closing device. In a refrigeration cycle apparatus including a refrigerant circuit including a compressor, a condenser, a throttle device, and an evaporator,
An oil separator provided on the refrigerant discharge side of the compressor, for separating the refrigerant and the refrigerating machine oil;
An oil reservoir connected to the oil separator and storing refrigerating machine oil;
Includes a flow control device for regulating the flow rate of refrigerating machine oil, the first oil return portion of the overflow oil from the oil reservoir is connected to the suction side of the oil reservoir and the compressor back to the compressor When,
Including a first opening / closing device that is switched between open and closed, and connected to the oil reservoir so that one end is located below a connection position between the first oil return portion and the oil reservoir, and the other end is the A second oil return unit connected to the refrigerant suction side of the compressor and returning the refrigeration oil stored in the oil storage unit to the compressor;
An upstream oil return pipe connecting the oil separator and the oil reservoir;
A control device that opens the first opening and closing device when starting the compressor, and closes the first opening and closing device after returning the refrigeration oil stored in the oil reservoir to the compressor;
With
The oil storage unit includes a storage container for storing refrigeration oil,
The first oil return portion is provided with the flow rate adjusting device, and includes a downstream oil return pipe that connects the storage container and a suction side of the compressor,
The upstream oil return pipe is provided with a second opening / closing device,
The downstream oil return pipe is provided with a fourth opening / closing device,
The control device opens the second opening / closing device and the fourth opening / closing device when starting up the compressor. In a refrigeration cycle apparatus including a refrigerant circuit including a compressor, a condenser, a throttle device, and an evaporator,
An oil separator provided on the refrigerant discharge side of the compressor, for separating the refrigerant and the refrigerating machine oil;
An oil reservoir connected to the oil separator and storing refrigerating machine oil;
Includes a flow control device for regulating the flow rate of refrigerating machine oil, the first oil return portion of the overflow oil from the oil reservoir is connected to the suction side of the oil reservoir and the compressor back to the compressor When,
Including a first opening / closing device that is switched between open and closed, and connected to the oil reservoir so that one end is located below a connection position between the first oil return portion and the oil reservoir, and the other end is the A second oil return unit connected to the refrigerant suction side of the compressor and returning the refrigeration oil stored in the oil storage unit to the compressor;
An upstream oil return pipe connecting the oil separator and the oil reservoir;
An accumulator connected to the suction side of the compressor together with the first oil return part and the second oil return part;
An accumulator connecting pipe connected to the accumulator;
A control device that opens the first opening and closing device when starting the compressor, and closes the first opening and closing device after returning the refrigeration oil stored in the oil reservoir to the compressor;
With
The oil storage unit includes a storage container for storing refrigeration oil,
The first oil return portion is provided with the flow rate adjusting device, and includes a downstream oil return pipe that connects the storage container and a suction side of the compressor,
The upstream oil return pipe is provided with a second opening / closing device,
One end of the accumulator connection pipe is connected to the oil separator side of the upstream oil return pipe from the connection position of the second switchgear, and the other end of the accumulator connection pipe is connected to the accumulator,
The accumulator connecting pipe is provided with a third opening / closing device,
The control device opens the third opening / closing device when starting the compressor. In a refrigeration cycle apparatus including a refrigerant circuit including a compressor, a condenser, a throttle device, and an evaporator,
An oil separator provided on the refrigerant discharge side of the compressor, for separating the refrigerant and the refrigerating machine oil;
An oil reservoir connected to the oil separator and storing refrigerating machine oil;
Includes a flow control device for regulating the flow rate of refrigerating machine oil, the first oil return portion of the overflow oil from the oil reservoir is connected to the suction side of the oil reservoir and the compressor back to the compressor When,
Including a first opening / closing device that is switched between open and closed, and connected to the oil reservoir so that one end is located below a connection position between the first oil return portion and the oil reservoir, and the other end is the A second oil return unit connected to the refrigerant suction side of the compressor and returning the refrigeration oil stored in the oil storage unit to the compressor;
An oil return pipe connecting the oil separator and the oil reservoir;
A control device that opens the first opening and closing device when starting the compressor, and closes the first opening and closing device after returning the refrigeration oil stored in the oil reservoir to the compressor;
With
The oil reservoir is
A storage container for storing refrigerating machine oil;
One end is connected to the upper part of the storage container, the other end is connected to the oil return pipe and the first oil return part, and extends from the lower side to the upper side from the upper part of the storage container to the first oil return part. viewing including the formation connection tube so that,
The connecting pipe is provided with a second opening / closing device,
The control device opens the second opening / closing device when the compressor is started. A refrigeration cycle device. The controller is
The refrigeration cycle apparatus according to any one of claims 2 to 4, wherein the second opening / closing device is opened when the compressor is started. The controller is
The refrigeration cycle apparatus according to claim 5 or 6, wherein the first opening / closing device is closed after starting the compressor and opening the first opening / closing device and the second opening / closing device. The controller is
The refrigeration cycle apparatus according to any one of claims 5 to 7, wherein the second opening / closing device is closed when the compressor is stopped. The controller is
3. When the compressor is started, the third opening / closing device is opened, then the first opening / closing device and the second opening / closing device are opened, and the third opening / closing device is closed. 4. The refrigeration cycle apparatus according to 4. The controller is
The refrigeration cycle apparatus according to claim 9, wherein after opening the first switchgear and the second switchgear and closing the third switchgear, the first switchgear is closed. The controller is
The refrigeration cycle apparatus according to claim 9 or 10, wherein when the compressor is stopped, the second opening / closing device and the third opening / closing device are closed. A heater for heating the oil reservoir;
The controller is
The refrigeration cycle apparatus according to claim 8 or 11, wherein the heater is driven and the second opening / closing device is opened before the compressor is started. A discharge pipe connecting the discharge side of the compressor and the oil separator;
The discharge pipe is
It forms so that the outer peripheral surface of the said oil storage part may be contacted. The refrigerating-cycle apparatus as described in any one of Claims 1-12. The oil reservoir is
The refrigeration cycle apparatus according to any one of claims 1 to 13, comprising a pipe formed in a spiral shape.

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