JPH11142002A - Refrigerating air conditioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge the necessity of operation with uniform oil distribution and distribute a refrigerating machine oil uniformly by forming a heat source means of large capacity by combining a primary heat source unit and a secondary heat source unit and comparing an operation time of each heat source unit with a time that can be used for operation represented by a specific expression by means of a compressor operation timing means. SOLUTION: An operation with uniform oil distribution is performed only when a refrigerating machine oil inside of one of a primary oil sump 7 and a secondary oil sump 107 is empty in order to solve uneven refrigerator oil distribution between a primary heat source unit 1 and a secondary heat source unit 101. A time TO available for operation until the refrigerating machine oil inside an oil sump is empty is expressed as TO=χ×ρ/(R5-R3) where an amount of oil returning from the oil sump to a compressor is defined as R5, an amount of oil returning from an oil separator to the oil sump is defined as R3, oil density is defined as ρ, and an amount of oil in the oil sump is defined as χ. Here, an operation time of a primary compressor and a secondary compressor is compared with the TO by means of a compressor operation timing means 201 in order to judge the necessity of an operation with uniform oil distribution by means of a uniform oil operation necessity judging 202.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration air conditioner in which a large-capacity heat source means formed by combining a plurality of heat source units is connected to a use side load by a single refrigerant system. .

[0002]

FIG. 17 is a refrigerant circuit diagram showing a conventional refrigeration air conditioner. In the figure, 1 is a main heat source unit, one or more output controllable main compressors 2, main oil separators 3, main four-way switching valves 4, main heat exchangers 5, 1 and 2 each having the same capacity or different capacities. The main blower 6, the main oil sump 7, the main liquid sump 8, the main oil separator 3, and the main connecting pipe 9 connecting the main oil sump 7, the main compression of which can be controlled from the main oil sump 7. From the main oil return circuit 10 and the main reservoir 8 for returning the refrigerating machine oil to the compressor 2
And a main liquid return circuit 11 for returning the liquid to the apparatus.

[0003] Reference numeral 101 denotes a slave heat source unit, which includes one or more slave compressors 102, slave oil separators 103, and slave four-way switching valves 10 each of which can output at least one constant output or output of the same capacity or different capacities.
4. Secondary heat exchanger 105, one or more output-controllable secondary blowers 106, secondary oil reservoir 107, secondary liquid reservoir 108, secondary connecting pipe 10 connecting secondary oil separator 103 and secondary oil reservoir 107
9. A return oil circuit 110 for returning the refrigerating machine oil from the slave oil reservoir 107 to the slave compressor 102, and the slave compressor 1 from the slave fluid reservoir 108
The return liquid circuit 111 is configured to return the liquid to the liquid 02.

[0004] Reference numeral 12 denotes a use side heat exchanger connected in parallel to the main heat source unit 1 and the sub heat source unit 101 via a use side flow control valve 13, and reference numeral 14 denotes a liquid side converging section. The pipe line to which the heat exchanger 12 is connected is connected to the pipe line to which the slave heat source device 101 and the use side heat exchanger 12 are connected. Reference numeral 15 denotes a gas-side junction, which connects a pipe connecting the main heat source unit 1 and the use-side heat exchanger 12 to a pipe connecting the slave heat source unit 101 and the use-side heat exchanger 12.

[0005] The conventional refrigeration air conditioner is configured as described above, and a refrigerant circuit is configured by using the main heat source unit 1, the auxiliary heat source unit 101 and the use side heat exchanger 12 as main parts. And
A required air conditioning operation is performed via the use side heat exchanger 12 by the outputs of the main heat source unit 1 and the sub heat source unit 101.

[0006]

In the conventional refrigeration air conditioner as described above, the main heat source unit 1 and the sub heat source unit 101 are used.
By combining a plurality of heat source devices, a large-capacity heat source means is formed, and a refrigerant circuit in which the heat source means is arranged is configured. In such a configuration, the use side heat exchanger 12
It is desirable that the amount of the refrigerating machine oil returned from each of the heat source units is returned to each of the heat source units.

However, since the main heat source unit 1 and the slave heat source unit 101 are separately arranged, the control is performed so that the amount of the returned refrigerating machine oil is equal to the amount of the refrigerating machine oil actually discharged from each heat source unit. It becomes difficult to do so in proportion to the increase in the number of installed heat source devices. For this reason, the refrigerating machine oil tends to be excessive in some of the heat source machines, and the refrigerating machine oil tends to be in short in the other heat source machines, and the operating reliability of the compressor in the heat source machine in which the refrigerating machine oil is insufficient is reduced. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and there is provided a refrigeration air conditioner in which refrigeration oil returning from a use side heat exchanger is evenly distributed to a plurality of compressors of a plurality of heat source units. The purpose is to gain.

[0009]

In a refrigeration air conditioner according to the present invention, a main heat source unit having a main compressor, a main oil separator, a main heat exchanger, and a main oil reservoir whose output is controllable is provided. A secondary heat source unit having a secondary compressor, a secondary oil separator, a secondary heat exchanger, and a secondary oil reservoir that can output or control the output, a main heat source unit and a use side heat exchanger connected to the secondary heat source unit; The liquid-side junction connecting the pipe connecting the heat source unit and the use-side heat exchanger to the pipe connecting the slave heat source unit and the use-side heat exchanger, and connecting the main heat source unit and the use-side heat exchanger The gas-side junction connecting the pipeline to the pipeline connecting the slave heat source unit and the use side heat exchanger, the main oil sump and the slave oil sump are connected by the oil sump, and the oil sump The main oil reservoir side opening is disposed at a position that does not come into contact with the liquid in the main oil reservoir when the liquid amount in the main oil reservoir becomes equal to or less than the first predetermined amount, The oil sump circuit side opening of the sump line is provided with an oil equalizing circuit arranged at a position not in contact with the liquid in the oil sump when the amount of liquid in the oil sump falls below the second predetermined amount. The compressor operating time measuring means of the compressor and the slave compressor, and the operating time of the main compressor and the slave compressor by the compressor operating time counting means are compared with the time TO in Expression 1 described later, and the oil leveling operation is performed. An oil-equalizing operation necessity determining means for determining necessity is provided.

Further, in the refrigeration air conditioner according to the present invention, the main compressor and the auxiliary compressor whose operation output alternately increases or decreases for a predetermined time are controlled by the oil equalizing operation necessity judging means by the oil equalizing operation necessity judging means. A compressor is provided.

Also, in the refrigeration air conditioner according to the present invention, the oil equalizing operation necessity judging means provided in the bypass circuit between the discharge portion of the main compressor of the main heat source unit and the main oil reservoir portion. A main opening / closing valve which is controlled through the operation necessity determination and is opened for a predetermined time; and a bypass circuit provided between the discharge part of the sub-compressor of the sub-heat source unit and the sub-oil storage part, and A slave on-off valve is provided which is controlled through the oil equalizing operation necessity determination and is closed when the main on-off valve is opened.

In the refrigerated air conditioner according to the present invention, the main low pressure detecting means provided on the main heat source unit side, the sub low pressure detecting means provided on the sub heat source unit side, and the main low pressure detecting unit First convergence determination means that operates when the detection values of both the means and the sub-low pressure detection means converge to a first predetermined value, and a second convergence determination means that operates when the detection values of the two converge to a second predetermined value Convergence determination means, convergence time timer means for measuring convergence time by the first convergence determination means and the second convergence determination means, main blast output adjustment control means for controlling the blast output of the main blower of the main heat exchanger, and It operates through the auxiliary air output adjustment control means for controlling the air output of the auxiliary air blower of the heat exchanger and the oil equalization operation necessity determination of the oil equalization operation necessity determination means, and controls the air output of the main air blower and the auxiliary air blower to the main low pressure. The value detected through the pressure detection means Oil-equalizing operation in which the main airflow output adjustment control means and the subordinate airflow output adjustment control means are operated until the value detected through the pressure / pressure detection means converges to a predetermined value and the time value of the convergence time timer reaches a predetermined time. A control device is provided.

Further, in the refrigeration air conditioner according to the present invention, the main low pressure detecting means provided on the main heat source unit side, the sub low pressure detecting means provided on the sub heat source unit side, and the main low pressure detecting unit First convergence determination means that operates when the detection values of both the means and the sub-low pressure detection means converge to a first predetermined value, and a second convergence determination means that operates when the detection values of the two converge to a second predetermined value Convergence determination means, convergence time timer means for measuring the convergence time by the first convergence determination means and the second convergence determination means, and a flow control valve provided in a pipeline between the slave heat exchanger and the liquid side junction Operating through the oil equalization operation necessity determination means of the oil equalization operation necessity determination means, and the value detected by the flow control valve through the main low pressure detection means and the value detected through the secondary low pressure detection means are a predetermined value. And the time value of the convergence time timer reaches the predetermined time. A flow control valve adjusting device for operating the flow control valve is provided to.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 1 to 7 are diagrams showing an example of an embodiment of the present invention. FIG. 1 is a refrigerant circuit diagram, FIG. 2 is a graph conceptually showing an oil balance in the heat source unit of FIG. 1, and FIG. 4 is an oil balance relationship graph on the main heat source unit side related to FIG. 4, FIG. 4 is an oil balance relationship graph on the slave heat source unit side related to FIG. 2, FIG. 5 is an oil return circuit diagram relating to the oil balance of the refrigerant circuit of FIG. FIG. 7 is a graph showing an oil balance relationship with respect to the amount of circulating refrigerant in the refrigerant circuit of FIG. 1, and FIG. 7 is a flowchart illustrating control of the refrigerant circuit of FIG.

In the figure, reference numeral 1 denotes a main heat source unit, which is constituted by one or more units, and in the case of one unit, is constituted by a compressor whose output can be controlled. A combination of a constant output compressor of the same capacity as the compressor or a combination of output controllable compressors, or a combination of a constant output compressor of a different capacity or a combination of output controllable compressors; Main oil separator 3, main four-way switching valve 4, main heat exchanger 5, one or more output-controllable main blowers 6, main oil reservoir 7, main liquid reservoir 8, main oil separator 3 and main oil A main connecting pipe 9 connected to the reservoir 7, a main oil return circuit 10 for returning refrigeration oil from the main oil reservoir 7 to the main compressor 2, and a main liquid return circuit for returning liquid to the main compressor 2 from the main liquid reservoir 8. 11.

Reference numeral 101 denotes a slave heat source unit, which includes one or more slave compressors 102, slave oil separators 103, and slave four-way switching valves 10 each having the same capacity or different capacities and capable of constant output or output control.
4. Secondary heat exchanger 105, one or more output-controllable secondary blowers 106, secondary oil reservoir 107, secondary liquid reservoir 108, secondary connecting pipe 10 connecting secondary oil separator 103 and secondary oil reservoir 107
9. A return oil circuit 110 for returning the refrigerating machine oil from the slave oil reservoir 107 to the slave compressor 102, and the slave compressor 1 from the slave fluid reservoir 108
The return liquid circuit 111 is configured to return the liquid to the liquid 02.

Reference numeral 12 denotes a use side heat exchanger connected in parallel to the main heat source unit 1 and the sub heat source unit 101 via a use side flow control valve 13; The pipe line to which the heat exchanger 12 is connected is connected to the pipe line to which the slave heat source device 101 and the use side heat exchanger 12 are connected. Reference numeral 15 denotes a gas-side junction, which connects a pipe connecting the main heat source unit 1 and the use-side heat exchanger 12 to a pipe connecting the slave heat source unit 101 and the use-side heat exchanger 12.

Reference numeral 16 denotes an oil leveling circuit, in which the main oil reservoir 7 and the auxiliary oil reservoir 107 are connected by an oil reservoir, and an opening of the oil reservoir on the main oil reservoir side is formed in the main oil reservoir 7. When the liquid amount becomes equal to or less than the first predetermined amount, the oil reservoir is disposed at a position not in contact with the liquid in the main oil reservoir 7, and the opening in the auxiliary oil reservoir side of the oil reservoir pipe is the liquid in the auxiliary oil reservoir 107. When the amount becomes equal to or less than the second predetermined amount, the oil is disposed at a position not in contact with the liquid in the oil reservoir 107.

Go is the discharge oil amount relative to the refrigerant circulation amount GR of each heat source unit, OS is the oil separation efficiency by the oil separator, R1 is the amount of circulating oil outside each heat source unit system, and R2 is the outflow unit outside each heat source unit system. The amount of oil returned from the gas-side merging portion 15 and the liquid-side merging portion 14 to each heat source unit with respect to the circulated oil amount R1, the amount of oil returned from the oil separator to the oil sump, and the range of R4 from the oil sump to the compressor. Returned oil amount to R
5 is the amount of oil returned from the oil reservoir to the compressor. Note that a at the end of each symbol indicates an amount related to the main heat source unit 1, and b indicates an amount related to the sub heat source unit 101.

In FIG. 2, the horizontal axis represents the refrigerant circulation amounts GRa and GRb of the main heat source unit 1 and the sub heat source unit 101, and the vertical axis represents the oil amounts Goa and G discharged from the main heat source unit 1 and the sub heat source unit 101.
ob. 3 and 4, the horizontal axis represents the circulating oil amounts R1a and R1b of the main heat source unit 1 and the sub-heat source unit 101, and the vertical axis represents the oil return amount R from the gas-side junction 15 and the liquid-side junction 14.
2a and R2b are shown.

In the following, the main compressor 2 of the main heat source unit 1 is assumed to be one output control type compressor, and the sub heat source unit 101
Of the secondary compressor 102 will be described as one constant output compressor. However, the main compressor 2 is composed of one or a plurality of compressors. In the case of one compressor, it is composed of a compressor whose output can be controlled. A similar effect can be obtained by a combination of a constant-output compressor or a compressor whose output is controllable or a combination of a constant-output compressor or a compressor whose output is controllable. Further, the same effect can be obtained even when the slave compressor 102 is constituted by one or more compressors having appropriate capacity and appropriate output form.

Also, in the above-described combination of compressors, one or more main heat source units 1 are combined with a plurality of auxiliary heat source units 101 in the above-described combination of compressors. Can obtain the same effect.

FIG. 2 shows that the oil discharge amount Go and the circulating oil amount R1 to the outside of each heat source system increase as the refrigerant circulation amount GR increases, and the oil return amounts R4 and R5 are the oil discharge amounts. In proportion to Go, the oil return amount R3 shows a substantially constant value with respect to the refrigerant circulation amount GR. Hereinafter, a case where the oil discharge amount Goa of the main heat source unit 1 is larger than the oil discharge amount Gob of the sub heat source unit 101 will be described as an example.

In FIGS. 3 and 4, the amount of oil returned R with respect to the amount of circulating oil R1 from the main heat source unit 1 and the sub heat source unit 101 is shown.
2 shows a deviation of 2. That is, if the oil return amount R2 is on the primary straight line in FIGS. 3 and 4, the main heat source unit 1 and the sub heat source unit 10
This indicates that the returned oil amount R2 for the circulating oil amount R1 of 1 is appropriate.

In the following, as an example, when the circulating oil amount R1a on the main heat source unit 1 increases, the oil return amount R2a on the main heat source unit 1 side decreases, and the amount of the decrease is as shown in region A of FIG. Oil is excessively returned to the heat source device 101 side. When the circulating oil amount R1a of the main heat source unit 1 decreases, the oil return amount R to the main heat source unit 1 decreases.
The case where 2a increases and the oil is excessively returned to the main heat source unit 1 side, and the excess amount decreases the amount of oil returned to the sub heat source unit 101 side as shown in a region B in FIG.

In the refrigerated air conditioner configured as described above, the main heat source unit 1, the auxiliary heat source unit 101, and the use side heat exchanger 12 constitute a main part of a refrigerant circuit. Then, the required air conditioning is performed via the use side heat exchanger 12 by the outputs of the main heat source unit 1 and the sub heat source unit 101.

The oil equalizing circuit 16 is provided between the main heat source unit 1 and the auxiliary heat source unit 101, and the amount of oil returned to the two units is imbalanced with respect to the amount of oil discharged to the two units. If one of the two heat source units has a shortage of refrigeration oil and the other one has an excess of refrigeration oil, the oil is leveled between the main oil reservoir 7 and the auxiliary oil reservoir 107.

The first predetermined amount or the second predetermined amount of refrigerating machine oil in addition to the required refrigerating machine oil amount of the compressor is sealed in the main oil sump 7 and the sub oil sump 107. These predetermined amounts are used to operate both compressors for a predetermined time after the occurrence of imbalance when the amount of oil returned to the two is imbalanced with respect to the amount of refrigerating machine oil discharged from the two. This is the required amount of refrigerating machine oil.

Hereinafter, the behavior of the refrigerant will be described in the case of the cooling operation indicated by the solid arrow in FIG. That is,
The high-temperature, high-pressure gas refrigerant flowing out of the main compressor 2 of the main heat source unit 1 flows to the main heat exchanger 5 via the main four-way valve 4. Here, the heat is radiated to become a high-pressure liquid refrigerant, and then exits the main heat source unit 1 and reaches the liquid-side junction 14.

Similarly, in the slave heat source unit 101, the slave heat exchanger 10 is sent from the slave compressor 102 via the slave four-way valve 104.
5 and merges with the liquid refrigerant from the main heat source unit 1 at the liquid side junction 14. Next, the combined liquid refrigerant flows to the use-side flow control valve 13 and is decompressed, becomes a low-temperature low-pressure two-phase refrigerant, flows to the use-side heat exchanger 12, absorbs heat, and almost becomes gaseous. Then, the low-pressure gas refrigerant is separated into the main heat source unit 1 side and the sub heat source unit 101 side at the gas side junction 15.

Then, the refrigerant flowing to the main heat source unit 1 enters the main liquid reservoir 8 through the main four-way valve 4 and separates the liquid refrigerant which has been partially evaporated, and only the gas refrigerant flows to the main compressor 2. Return. Also,
The slave heat source unit 101 also has a slave four-way valve 10 similar to the main heat source unit 1 side.
4 and returns to the secondary compressor 102 via the secondary liquid storage section 108.

Next, the case of the heating operation shown by the broken arrow in FIG. 1 will be described. That is, the high-temperature, high-pressure gas refrigerant that has exited the main compressor 2 of the main heat source unit 1 reaches the gas-side junction 15 via the main four-way valve 4. Here, in the same manner as the main heat source unit 1 side, it merges with the gas refrigerant flowing from the sub heat source unit 101, flows into the use side heat exchanger 12, and radiates and condenses the gas refrigerant to become a high pressure liquid refrigerant.

The refrigerant flowing out of the use side heat exchanger 12 flows to the use side flow control valve 13 and is reduced in pressure to become a low-pressure two-phase refrigerant. The two-phase refrigerant directly reaches the liquid-side merging section 14 and is separated into the main heat source unit 1 side and the sub heat source unit 101 side. Most of the refrigerant flowing to the main heat source unit 1 is absorbed and evaporated in the main heat exchanger 5, passes through the main four-way valve 4, is separated into gas and liquid by the main liquid reservoir 8, and only the gas refrigerant is transferred to the main compressor 2. Reach. Further, the refrigerant flowing from the liquid side merging section 14 to the sub heat source unit 101 is the sub heat exchanger 1
05, return to the slave compressor 102 via the slave four-way valve 104 and the slave liquid reservoir 108.

Next, the behavior of the refrigerating machine oil will be described in the case of a cooling operation indicated by a solid arrow in FIG. That is, the refrigerating machine oil is discharged together with the high-temperature, high-pressure gas refrigerant that has exited the main compressor 2 of the main heat source unit 1, and is separated into the gas refrigerant and the refrigerating machine oil by the main oil separator 3.

The main oil separator 3 recovers most of the refrigerating machine oil, but a part of the oil flows together with the gas refrigerant through the main four-way valve 4 to the main heat exchanger 5, and then exits the main heat source unit 1 and joins the liquid side junction. It reaches 14. The refrigerating machine oil separated by the main oil separator 3 is supplied to the main connecting pipe 9 connecting the main oil separator 3 and the main oil reservoir 7.
And is returned to the main compressor 2 by the main oil return circuit 10.

In the auxiliary heat source unit 101, as in the main heat source unit 1, the refrigerating machine oil discharged from the sub compressor 102 is separated by the sub oil separator 103 into gas refrigerant and refrigerating machine oil.
And the refrigerating machine oil is partially mixed with the gas refrigerant,
04 to the slave heat exchanger 105, and then the slave heat source unit 1
After exiting from the position 01, it reaches the liquid side merging section 14. In addition, the slave oil separator 1
The refrigerating machine oil separated at 03 is stored in the secondary oil reservoir 107 through the secondary connection pipe 109 connecting the secondary oil separator 103 and the secondary oil reservoir 107, and is returned to the secondary compressor 102 by the return oil circuit 110. Reflux.

On the other hand, the main oil separator 3 or the secondary oil separator 103
The main heat source unit 1 that flows out of the main heat source unit 1 and the sub heat source unit 101 without being separated by the
And the refrigerating machine oil from the subordinate heat source unit 101 goes to the use side heat exchanger 12 as it is. And the use side flow control valve 13
The refrigerant is turned into a low-temperature, low-pressure two-phase refrigerant, which absorbs heat in the use-side heat exchanger 12, so that most of the refrigerant becomes gaseous together with the main-heat source unit 1 and the auxiliary heat source unit 101 at the gas-side junction 15. Divide into sides.

The refrigerating machine oil flowing to the main heat source unit 1 enters the main liquid reservoir 8 together with the unevaporated liquid refrigerant via the main four-way valve 4 and is separated and stored from the gas refrigerant. This main reservoir 8
The refrigerating machine oil stored in the main compressor 2 is returned to the main compressor 2 by a main liquid return circuit 11 for returning a mixed liquid of the refrigerant and the refrigerating machine oil from the main liquid reservoir 8 to the main compressor 2. The slave heat source unit 101 also returns to the slave compressor 102 via the slave four-way valve 104, the slave liquid storage unit 108, and the slave liquid circuit 111 in the same manner as the main heat source unit 1 side.

Next, the behavior of the refrigerating machine oil will be described in the case of a heating operation indicated by a broken arrow in FIG. That is, the refrigerating machine oil discharged together with the high-temperature, high-pressure gas refrigerant exiting the main compressor 2 of the main heat source unit 1 is separated into the gas refrigerant and the refrigerating machine oil by the main oil separator 3.

Then, most of the refrigerating machine oil is recovered by the main oil separator 3, but a part thereof exits the main heat source unit 1 via the main four-way valve 4 together with the gas refrigerant and reaches the gas side junction 15. Further, the refrigerating machine oil separated by the main oil separator 3 is stored in the main oil reservoir 7 through a main connecting pipe 9 connecting the main oil separator 3 and the main oil reservoir 7, and is returned to the main oil return circuit. The refrigerant is returned to the main compressor 2 by 10.

Further, in the slave heat source unit 101, similarly to the main heat source unit 1, the refrigerating machine oil discharged from the slave compressor 102 is separated into the gas refrigerant and the refrigerating machine oil by the slave oil separator 103.
And the refrigerating machine oil is partially mixed with the gas refrigerant,
04 to the slave heat exchanger 105, and then the slave heat source unit 1
After exiting 01, it reaches the gas-side merging section 15. The refrigerating machine oil separated by the slave oil separator 103 is stored in the slave oil reservoir 107 through a slave connection pipe 109 connecting the slave oil separator 103 and the slave oil reservoir 107, and is returned to the return oil circuit. The flow is returned to the slave compressor 102 by 110.

On the other hand, the main oil separator 3 or the secondary oil separator 103
The refrigerating machine oil from the main heat source unit 1 and the sub heat source unit 101 that has flowed out of the main heat source unit 1 and the sub heat source unit 101 without being separated at the gas side and joined at the gas side junction unit 15 is used as it is as the use side heat exchanger. Go to 12. And the use side heat exchanger 12
At the liquid side merging section 14, the refrigerant is separated into the main heat source unit 1 and the sub heat source unit 101 together with the refrigerant which becomes a liquid refrigerant and becomes a low-temperature and low-pressure two-phase state by being reduced in pressure by the use side flow control valve 13.

The refrigerating machine oil flowing to the main heat source unit 1 passes through the main heat exchanger 5 and the main four-way valve 4 and enters the main liquid reservoir 8 together with the unevaporated liquid refrigerant, where it is separated from the gas refrigerant and stored. The refrigerating machine oil stored in the main liquid reservoir 8 returns to the main compressor 2 by a main liquid return circuit 11 that returns a mixed liquid of the refrigerant and the refrigerating machine oil from the main liquid reservoir 8 to the main compressor 2.

Similarly to the main heat source unit 1, the refrigerating machine oil stored in the sub-liquid storage unit 108 together with the unevaporated liquid refrigerant passes through the sub heat exchanger 105 and the sub four-way valve 104 as in the main heat source unit 1 side. The secondary liquid is returned to the secondary compressor 102 by the secondary liquid circuit 111 that returns the mixed liquid of the refrigerant and the refrigerating machine oil from the secondary liquid storage unit 108 to the secondary compressor 102.

Here, a description will be given of a process in which the refrigeration oil is insufficient on one side of the main heat source unit 1 and the auxiliary heat source unit 101 and the refrigeration oil is excessive on the other side. Note that such a situation is caused by an imbalance in the amount of oil returned to the two at the liquid-side merging portion 14 and the gas-side merging portion 15 with respect to the amount of the refrigerating machine oil discharged from the both due to the behavior of the above-described refrigerating machine oil. Occurs.

That is, as shown in FIG. 2, the oil discharge amount Goa of the main compressor 2 of the main heat source unit 1 is compared with that of the sub heat source unit 10.
The oil discharge amount Gob of the first secondary compressor 102 is smaller, and as shown in FIGS. 3 and 4, the return oil amount R2a is smaller than the circulating oil amount R1a flowing out of the main heat source unit 1 and the secondary compressor 102 10
When the oil return amount R2b is excessive with respect to the oil discharge amount Gob of No. 2,
That is, the region A in FIG. 4 will be described with reference to FIG.

That is, as shown in FIG. 2, when the oil discharge amount Goa of the main compressor 2 increases, the amount of oil returned from the main oil separator 3 having a constant oil return capacity to the main oil reservoir 7 at a certain constant differential pressure. Oil separation efficiency OSa in the main oil separator 3 with respect to R3a
Since (= R3a / Goa) decreases, the circulating oil amount R1a flowing out of the main heat source unit 1 increases. Further, as shown in the region A in FIG. 3, the liquid side merging portion 14 and the gas side merging portion 1
5 is smaller than the circulating oil amount R1a flowing out of the main heat source unit 1, the amount of oil returned R4a from the main reservoir 8 to the main compressor 2 is also reduced.

As the oil discharge amount Goa increases, the amount R3a of oil returned from the main oil separator 3 to the main oil reservoir 7 is small, and the amount of oil returned from the main oil reservoir 7 to the main compressor 2 is small. Since R5a is returned in substantially the same amount as the oil discharge amount Goa, the amount of refrigerating machine oil in the main oil reservoir 7 decreases with time, and R5a> R3
a. As a result, when the refrigerating machine oil amount in the main oil reservoir 7 becomes empty, Goa> R5a (= R3a) + R4a, and even the refrigerating machine oil amount in the main compressor 2 eventually decreases.

Further, as compared with the main compressor 2 having a large oil discharge amount Goa as shown in FIG. 2, the secondary compressor 102 having a relatively small oil discharge amount Gob has a fluid Oil return amount R2 from the side merging portion 14 and the gas side merging portion 15
Since b is larger than the circulating oil amount R1b flowing out of the auxiliary heat source device 101 system, the oil return amount R4b from the auxiliary liquid reservoir 108 to the auxiliary compressor 102 is also increased.

At this time, since the amount of refrigerating machine oil in the secondary compressor 102 increases, the oil discharge amount Gob slightly increases and Gob '
However, since the oil separation efficiency OSa is in a constant region with respect to the oil discharge amount Gob, the oil separation unit 103 moves the oil separation efficiency
Only the absolute oil return amount R3b increases, and the oil return amount R1b remains constant.

Further, the secondary compressor 102
The amount of oil returned R5b to the secondary compressor 10
Since the oil is returned in substantially the same amount as the oil discharge amount Gob before the oil return amount R4b to 2 increases, Gob ′ = R5b (= Go
b) + R4b, R5b <R3b, and the amount of refrigerating machine oil in the slave oil reservoir 107 increases over time.

In the above description, if the refrigerating machine oil is unevenly distributed between both the main heat source unit 1 and the sub-heat source unit 101, the refrigerating machine oil amount of one of the two compressors decreases, and the operation reliability of the compressor is reduced. Mentioned the situation where sex is reduced. However, although this problem is solved by performing the oil equalizing operation between the two, the excessive oil equalizing operation causes a reduction in the comfort of the refrigeration air conditioning and the refrigeration air conditioning performance.

Accordingly, in the embodiment shown in FIGS. 1 to 7, the oil discharge amount Go of the two compressors and the deviation of the oil return amount to the two at the liquid side merging portion 14 and the gas side merging portion 15 and The refrigeration air conditioner is controlled so as to perform an appropriate oil leveling operation when the operation of both compressors reaches a predetermined time in consideration of the operation outputs of both compressors.

That is, the main heat source unit 1 and the sub heat source unit 101
In order to eliminate uneven distribution of refrigerating machine oil between the two, an appropriate oil leveling operation is performed to improve the operation reliability of the two compressors. Therefore, the oil leveling operation is performed only when the refrigeration oil inside one of the main oil reservoir 7 and the sub oil reservoir 107 is empty.

In order to perform such an oil equalizing operation, the oil discharge amount Go of the main compressor 2 and the sub compressor 102 and the liquid-side confluence 14
FIG. 6 shows the deviation of the oil return amount to the above and the operation output of the main compressor 2 and the sub compressor 102 in the gas-side merging section 15.
The frequency of the oil equalizing operation is suppressed by optimally setting the oil equalizing operation required, that is, the operable time until the refrigerating machine oil inside the oil reservoir becomes empty from the relationship shown in FIG.

Then, the aforementioned oil discharge amount Goa> Gob,
Considering the returned oil amount R2a <R2b, the operable time T until the refrigerating machine oil inside the oil reservoir becomes empty is expressed by the following equation 1.

(Equation 2) Here, χ: Refrigerant oil amount in the main oil reservoir 7 and the auxiliary oil reservoir 107 ρ: Oil density R5: Return from the main oil reservoir 7 and the auxiliary oil reservoir 107 to the main compressor 2 and the auxiliary compressor 102 Oil amount R3: Return amount of oil from the main oil separator 3 and the secondary oil separator 103 to the main oil reservoir 7 and the secondary oil reservoir 107

Then, the worst condition R5a = R5amax ≒ [Goamax (maximum oil discharge amount with respect to the refrigerant circulation amount max of the compressor) or the flow velocity max value in the suction pipe of the compressor, which is the worst condition in the operation range of the above-mentioned region A, R3a = R3amin (determined from the pipe diameter, length, and differential pressure across the main connecting pipe 9 connecting the main oil separator 3 and the main oil reservoir 7). The operable time Ta is obtained from the (min value).

When the refrigerating machine oil amount in the slave oil reservoir 107 of the slave heat source unit 101 decreases, that is, the oil discharge amount Goa
Considering <Gob and oil return amount R2a> R2b, the oil equalization operation required, that is, the operable time Tb until the refrigeration oil inside the oil reservoir becomes empty is the worst condition R5b.
= R5bmax ≒ [Gobmax (refrigerant circulation amount max of compressor
Oil flow rate max value) or the flow rate ma in the compressor suction pipe
x value, differential pressure before and after, oil return amount obtained by liquid refrigerant head
max value] and R3b = R3bmin (min value obtained from the pipe diameter, length, and front-rear differential pressure of the secondary connecting pipe 109 connecting the secondary oil separator 103 and the secondary oil reservoir 107) to obtain the operable time Tb. .

Therefore, the compressor operating time for performing unnecessary oil equalizing operation and performing proper oil equalizing operation is the operable time T
a or the operable time Tb, whichever is smaller. Then, the oil leveling operation is performed according to the flowchart shown in FIG. That is, in step 201, the operation time T of the main compressor 2 and the sub-compressor 102 is measured by the operation time measuring means 201.

Next, the routine proceeds to step 202, that is, to the oil equalizing operation necessity judging means 202. If the operation time T is smaller than the smaller of the operable time Ta and the operable time Tb, ie, if it is smaller than the operable time To, step 201
Return to step 203, and if larger, proceed to step 203. Then, the routine proceeds to step 203, where the oil equalizing operation is performed.

Thus, the main heat source unit 1 and the sub heat source unit 1
01 in the refrigeration air conditioner in which a refrigerant circuit is constituted by the heat source means, the amount of oil returned to each heat source unit at the liquid-side junction 14 and the gas-side junction 15. When the operation of each heat source unit has continued for a predetermined time, the oil equalizing operation is performed through the determination of the oil equalizing operation necessity determination means 202 in consideration of the deflection of the heat source units.

Then, the refrigerating machine oil returned from the use side heat exchanger 12 by the oil equalizing operation determined by the oil equalizing operation necessity determining means 202 is subjected to the main heat source unit 1 and the sub heat source unit 1 at appropriate frequencies.
01 are evenly distributed. Therefore, without accompanying the comfort of refrigeration air conditioning and the performance of refrigeration air conditioning,
The operation reliability of the main compressor 2 and the sub compressor 102 can be improved.

Embodiment 2 8 to 11 are views showing an example of another embodiment of the present invention, and FIGS. 8 to 11 are graphs showing the compressor operation output during the oil equalization operation during the normal operation. The configuration of the refrigeration air conditioner,
The flow of the refrigerant and the flow of the refrigerating machine oil during normal operation are as shown in FIG.
7 to FIG. 7, and the oil leveling operation is performed as described below.

That is, step 2 in FIG.
02, that is, at the time of oil equalization operation necessity determination by the oil equalization operation necessity determination means 202, as shown in FIG. 8, depending on the compressor operation output during normal operation, refrigeration between the heat source units during oil equalization operation. The output of the compressor of each heat source device is increased or decreased for a predetermined time during which the machine oil can move. The internal pressure P of the main oil reservoir 7 in the heat source unit
a and the internal pressure Pb of the slave oil reservoir 107 to generate a differential pressure to move the refrigerating machine oil.

As shown in FIG. 8, when the operation output of the main compressor 2 is smaller than the operation output of the slave compressor 102 during normal operation, that is, the part A shown in FIG. 8 and the case of FIG. The operation output of the compressor 2 is increased for a predetermined time so as to be larger than the operation output of the slave compressor 102.
As a result, the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the sub oil reservoir 107 is reversed, that is, Pa> Pb at normal times.
→ When oil leveling is established, Pa <Pb, and the refrigerating machine oil in the secondary oil reservoir 107 is moved to the main oil reservoir 7.

Then, after a predetermined time of the oil equalizing operation has elapsed, the operation state of the main compressor 2 and the sub compressor 102 during the normal operation is returned to the original operation state. At this time, the pressure difference between the main oil sump 7 and the sub oil sump 107 returns to the original pressure, and the refrigerating machine oil in the main oil sump 7 is moved to the sub oil sump 1.
Move to 07. The opening of the oil equalizing circuit 16 is arranged at a position where it does not come into contact with the liquid level in the main oil reservoir 7 when the liquid amount in the main oil reservoir 7 becomes equal to or less than the first predetermined amount. Reservoir 1
When the liquid amount in 07 becomes equal to or less than the second predetermined amount, it is arranged at a position not in contact with the liquid surface in oil reservoir 107. Therefore, when the oil leveling operation is performed, the main oil reservoir 7 and the secondary oil reservoir 10
The refrigerating machine oil amount of 7 does not decrease below a predetermined amount.

For example, in the part A shown in FIG. 8 and the state shown in FIG. 9, the internal pressure Pa> Pb, and the refrigerating machine oil tends to be unevenly distributed to the sub oil reservoir 107. For this reason, if the second predetermined amount or more of the refrigerating machine oil exists in the sub oil reservoir 107 and the refrigerating machine oil is insufficient on the main oil reservoir 7 side, the main oil reservoir 107 The refrigerating machine oil moves to the oil reservoir 7. However, the secondary oil reservoir 1
Only the excess oil of the second predetermined amount of 07 or more moves, and the second predetermined amount of the refrigerating machine oil is held in the slave oil reservoir 107.

Next, according to FIG. 8, the main compressor 2
When the operation output is the operation output of the secondary compressor 102, that is, the operation output of the main compressor 2 having at least one output control type compressor in the part B shown in FIG. Is increased for a predetermined time so as to be larger than the operation output of the above.

As a result, a differential pressure is generated between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the sub oil reservoir 107, that is, Pa = Pb at normal time → Pa <Pb at oil leveling.
The second predetermined amount or more of the refrigerating machine oil is moved to the main oil reservoir 7. Then, after a lapse of a predetermined time of the oil equalizing operation, the operation output of the main compressor 2 is reduced for a predetermined time so as to be smaller than the operation output of the sub compressor 102, and the internal pressure Pa of the main oil reservoir 7 and the sub output are reduced. The differential pressure is reversed to the internal pressure Pb of the oil reservoir 107 to make the oil level Pa <Pb → the oil level Pa> Pb.

As a result, the refrigerating machine oil of the first predetermined amount or more in the main oil reservoir 7 is moved to the auxiliary oil reservoir 107. And
After a lapse of a predetermined time, the operation state of the main compressor 2 and the sub-compressor 102 during the normal operation is restored. Further, according to FIG. 8, when the operation output of the main compressor 2 is greater than the operation output of the sub-compressor 102 during the normal operation, that is, the main compressor having at least one output control type compressor in the part C shown in FIG. The operation output of the compressor 2 is reduced for a predetermined time so as to be smaller than the operation output of the slave compressor 102.

As a result, the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the sub oil reservoir 107 is reversed, that is, the normal oil pressure Pa <Pb → the oil leveling oil Pa> Pb. Is moved to the secondary oil storage 107. Then, after a predetermined time of the oil equalizing operation has elapsed, the operation state of the main compressor 2 and the sub compressor 102 during the normal operation is returned to the original operation state.

At this time, the pressure difference between the main oil reservoir 7 and the sub oil reservoir 107 returns to the original pressure, and the second predetermined amount or more of the refrigerating machine oil in the sub oil reservoir 107 moves to the main oil reservoir 7. I do. In this manner, the main heat source unit 1 and the sub heat source unit 101 are combined to form a large-capacity heat source unit, and in the refrigeration air conditioner in which the refrigerant circuit is constituted by the heat source units, the main heat source unit 1 and the sub heat source unit The operation output difference of the machine 101 is reversed for a predetermined time.

As a result, the refrigerating machine oil returning from the use side heat exchanger 12 is equally distributed to the main heat source unit 1 and the sub heat source unit 101 by the oil equalizing operation of an appropriate frequency. Therefore, although detailed description is omitted, the same operation as the embodiment of FIGS. 1 to 7 can be obtained in the embodiment of FIGS. In the above description, the compressor operation output for adjusting the internal pressure difference between the main oil reservoir 7 and the sub oil reservoir 107 during the oil leveling operation is adjusted only on the main compressor 2 side.

However, when the output control type compressor is also provided on the slave compressor 102 side, the operation output of the main compressor 2 is kept as it is, and the compressor operation output is adjusted only by the slave compressor 102 side. Thus, even if the internal pressure difference between the main oil reservoir 7 and the sub oil reservoir 107 is set and the oil leveling operation is performed, the same operation as the embodiment of FIGS. 8 to 11 can be obtained. In addition, the operation output of both the main compressor 2 and the sub-compressor 102 is adjusted, and the main oil reservoir 7,
Even when the oil leveling operation is performed with the internal pressure difference of the slave oil reservoir 107 being set, the same operation as the embodiment of FIGS. 8 to 11 can be obtained.

Embodiment 3 FIG. 12 also shows an example of another embodiment of the present invention. FIG. 12 is an oil return circuit diagram relating to an oil balance of a refrigerant circuit in a refrigeration air conditioner. The configuration of the refrigeration air conditioner, the flow of the refrigerant, and the flow of the refrigerating machine oil during normal operation are the same as those in the embodiment of FIGS. 1 to 7 described above, and the oil leveling operation is performed as described below. . In the figure, the same reference numerals as those in FIG.

Reference numeral 17 denotes a main opening / closing valve provided in the main heat source unit 1, which is arranged in a bypass circuit between the discharge part of the main compressor 2 and the main oil reservoir 7. Reference numeral 117 denotes a slave on-off valve provided in the slave heat source unit 101, and a discharge part of the slave compressor 102 and a slave oil reservoir 1
07 in the bypass circuit. The main on-off valve 17 and the on-off valve 117 are connected to the main oil reservoir 7 internal pressure Pa and the auxiliary oil reservoir 107 internal pressure Pb at any operation output pattern of the corresponding main compressor 2 and auxiliary compressor 102, respectively. Set to a capacity that allows adjustment of differential pressure.

In the refrigeration air conditioner configured as described above, when the oil equalizing operation necessity determining means 202 determines that the oil equalizing operation is necessary, the control is performed as described below. In other words, as shown in FIG. 12, during the oil equalizing operation, regardless of the operation output of the main compressor 2 and the auxiliary heat compression 102, the main opening and closing is performed for a predetermined time during which the refrigerating machine oil can move between the main heat source unit 1 and the auxiliary heat source unit 101. The valve 17 and the slave on-off valve 117 are alternately opened and closed, so that the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the
Refrigeration oil is moved by applying a pressure difference between

For example, as shown in FIG. 12, the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pa of the secondary oil reservoir 107 during normal operation is Pa <Pb, and surplus oil stays in the main oil reservoir 7. However, if there is a shortage of refrigerating machine oil in the secondary oil reservoir 107,
The following control is performed.

That is, first, the main on-off valve 17 is opened for a predetermined time during which the refrigeration oil can move, and
As a> Pb, the refrigerating machine oil in the main oil reservoir 7 is moved to the slave oil reservoir 107 by the oil equalizing pipe 16. After a lapse of a predetermined time, the main on-off valve 17 is closed, and the sub-on-off valve 117 is opened for a predetermined time during which the refrigerating machine oil can move.
a <Pb so that the refrigerating machine oil in the slave oil reservoir 107 is
6 to the main oil reservoir 7. Next, after a lapse of a predetermined time for the oil leveling operation, the on-off valve 117 is closed, the oil leveling operation ends, and the operation returns to the normal operation.

The opening of the oil equalization circuit 16 is provided when the liquid level in the main oil reservoir 7 becomes equal to or less than the first predetermined amount.
Is disposed at a position not in contact with the liquid level in
When the liquid level becomes equal to or less than the second predetermined amount in the oil reservoir 7, the oil reservoir 1
07 in a position not in contact with the liquid surface. For this reason,
When the oil leveling operation is performed, the amount of the refrigerating machine oil in the main oil reservoir 7 and the sub oil reservoir 107 does not decrease beyond a predetermined amount.

For example, in the above-described state, if the main oil sump 7 has more than the first predetermined amount of refrigerating machine oil and the sub oil sump 107 is short of refrigerating machine oil, the main oil sump is operated by the oil equalizing operation. The refrigerating machine oil moves from the part 7 to the slave oil reservoir 107. But,
Only the excess refrigerating machine oil of the first predetermined amount or more in the main oil reservoir 7 moves, and the first predetermined amount of the refrigerating machine oil is held in the main oil reservoir 7.

In the above description, the main oil reservoir 7 and the secondary oil reservoir 10
7, the control of the oil leveling operation for moving the refrigerating machine oil has been described.
, The refrigerating machine oil is moved to the main oil reservoir 7 to perform oil leveling operation. The alternate opening / closing operation of the main opening / closing valve 17 and the slave opening / closing valve 117 is performed in an order corresponding to the moving direction of the refrigerating machine oil.

In this way, the main heat source unit 1 and the sub heat source unit 101 are combined to form a large-capacity heat source unit. In the refrigeration air conditioner in which the refrigerant circuit is constituted by this heat source unit, the main heat source unit 1 The main on-off valve 17 and the on-off valve 117 of the bypass circuit are opened and closed for a predetermined time during which the refrigerating machine oil can move between the sub heat source units 101.

As a result, the refrigerating machine oil returning from the use side heat exchanger 12 is equally distributed to the main heat source unit 1 and the sub heat source unit 101 by the oil equalizing operation of an appropriate frequency. Therefore, although detailed description is omitted, the same operation as the embodiment of FIGS. 1 to 7 can be obtained in the embodiment of FIG.

Further, it is also possible to perform the oil leveling operation by combining the method of performing the oil leveling operation by adjusting the compressor operation output in the embodiment of FIG. 12 and the method of the other embodiments. When the main oil reservoir 7, the sub oil reservoir 107 communicates with the main liquid reservoir 8, and the sub liquid reservoir 108, the main compressor 2, the sub heat compression 102, the main open / close valve 17, the sub open / close valve Valve 117
The operation in the embodiment of FIG. 12 can be obtained even in a configuration in which a bypass circuit is provided to the main liquid storage section 8 and the sub liquid storage section 108 via the.

Embodiment 4 FIGS. 13 and 14 also show an example of another embodiment of the present invention. FIG. 13 is a refrigerant circuit diagram, and FIG. 14 is a flowchart illustrating control of the refrigerant circuit of FIG. The configuration of the refrigeration air conditioner, the flow of the refrigerant, and the flow of the refrigeration oil during normal operation are the same as those in the above-described embodiment of FIGS. 1 to 7, and the oil leveling operation is performed as described below. Will be In the figure, the same reference numerals as those in FIGS.

Reference numeral 18 denotes main low pressure detecting means provided between the main four-way switching valve 4 and the main oil reservoir 7, and reference numeral 118 denotes a sub-pressure sensor provided between the sub-four-way switching valve 104 and the sub oil reservoir 107. The low pressure detecting means 19 is a first convergence determining means for determining whether or not the detection values of the main low pressure detecting means 18 and the sub low pressure detecting means 118 have converged to a first value set in advance.
Are the main low pressure detecting means 18 and the sub low pressure detecting means 11
The second convergence determination means determines whether the detected value of No. 8 has converged to a preset second value.

Reference numeral 21 denotes a convergence time measuring means for measuring a convergence time based on the judgments of the first convergence judging means 19 and the second convergence judging means 20, 22 denotes a main blast output adjustment control means of the main blower 6, and 122 denotes a sub-main blower. Reference numeral 106 denotes a subordinate air output adjustment control unit. Reference numeral 222 denotes an oil equalizing operation control device mainly including the first convergence determination unit 19, the second convergence determination unit 20, the convergence time timer 21, the main ventilation output adjustment control unit 22, and the secondary ventilation output adjustment control unit 122. is there.

The main low pressure detecting means 18 and the sub low pressure detecting means 118 may be disposed at appropriate low pressure lines connected to the suction sides of the corresponding main compressor 2 and sub compressor 102. The same operation as the above arrangement can be obtained.

In the refrigeration air conditioner configured as described above, the operation output of the main compressor 2 and the sub-compressor 102 remains unchanged regardless of the operation output of the main compressor 2 and the sub-compressor 102 during normal operation. , Low pressures in the main heat source unit 1 and the sub heat source unit 101 which are substantially equal to the internal pressures of the main oil reservoir 7 and the sub oil reservoir 107 are detected. The operation output of the main blower 6 and the sub main blower 106 is set so that the internal pressure difference between the main oil sump 7 and the sub oil sump 107 capable of moving the refrigerating machine oil through this detection can be secured.
That is, the oil leveling operation is performed by adjusting the air volume.

Then, the oil equalizing operation necessity determining means 20
When it is determined that the oil equalizing operation is necessary according to 2, the control according to the flowchart of FIG. 14 is performed. That is, in step 301, the operation time T of the main compressor 2 and the sub-compressor 102 is measured by the above-mentioned operation time measuring means 201.

Next, the routine proceeds to step 302, ie, the oil equalizing operation necessity judging means 202. If the operation time T is shorter of the operable time Ta and the operable time Tb, that is, smaller than the operation time To, the flow proceeds to step 301. Returning, if it is larger, the routine proceeds to step 303, where the oil leveling operation is performed. In step 304, the main low pressure detecting means 18 and in step 305, the sub low pressure detecting means 11
The corresponding low pressure of the heat source device is detected by 8 and the process proceeds to step 306.

In step 306, the first convergence is performed to move the refrigerating machine oil from the main oil reservoir 7 to the sub oil reservoir 107 regardless of the operation output of the main compressor 2 and the sub compressor 102 during the oil equalizing operation. If the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the secondary oil reservoir 107 of the determination means 19 is not Pa> Pb, the process proceeds to step 307, and if Pa> Pb, the process proceeds to step 308.
Proceed to.

Then, in step 307, the operation output of the main blower 6 is
The secondary blower 106 is controlled by the secondary blower output adjustment control means 122.
Is adjusted, and the process returns to step 306. Also,
In step 308, the convergence time timer 21 operates to proceed to step 309. If the time T1 of the convergence time timer 21 is not larger than the compressor operation time T, the process returns to step 308. If it is larger, the process proceeds to step 310.

Then, at step 310, the secondary oil reservoir 107
If the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the secondary oil reservoir 107 of the second convergence determination means 20 is not Pa <Pb in order to move the refrigeration oil from the main oil reservoir 7 to the main oil reservoir 7, the process proceeds to step 311. If Pa <Pb, the process proceeds to step 312.

Thus, in step 311, the operation output of the main blower 6 is controlled by the main blower output adjustment control means 22, and the slave blower 1
The operation output of step 06 is adjusted, and the process returns to step 310. Also, in step 312, the convergence time timer 21 operates to proceed to step 313. If the time T1 of the convergence time timer 21 is not larger than the compressor operating time T, the process returns to step 312. If it is larger, the process proceeds to step 314. Then, the oil leveling operation ends.

For example, during the heating operation, the first convergence determination means 1
9, the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the sub oil reservoir 107 is set to Pa> Pb, and
In order to increase the internal pressure Pa of the main oil reservoir 7 when the refrigerating machine oil is moved, the operation output of the main blower 6 is increased and the evaporation pressure of the main heat exchanger 5 is increased. Further, the slave oil reservoir 107
In order to lower the internal pressure Pb, the operation output of the follower blower 106 is reduced to lower the evaporation pressure of the slave heat exchanger 105.

At this time, the internal pressure Pa of the main oil reservoir 7 increases as the evaporation pressure increases, and the internal pressure Pb of the secondary oil reservoir 107 decreases as the evaporation pressure decreases. For this reason, the refrigerating machine oil in the main oil reservoir 7 moves to the slave oil reservoir 107. When the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the secondary oil reservoir 107 of the second convergence determination means 20 is set to Pa <Pb, and the refrigerating machine oil is moved from the secondary oil reservoir 107 to the main oil reservoir 7. The main oil reservoir 7
In order to reduce the internal pressure Pa, the operation output of the main blower 6 is reduced, and the evaporation pressure of the main heat exchanger 5 is reduced.

Further, in order to increase the internal pressure Pb of the slave oil reservoir 107, the operation output of the slave blower 106 is increased to increase the evaporation pressure of the slave heat exchanger 105. At this time, the internal pressure Pa of the main oil reservoir 7 decreases as the evaporation pressure decreases, and the internal pressure Pb of the secondary oil reservoir 107 increases as the evaporation pressure increases. Therefore, the refrigerating machine oil in the secondary oil reservoir 107 moves to the main oil reservoir 7.

In this manner, a large-capacity heat source means is formed by combining the main heat source unit 1 and the sub heat source unit 101. In the refrigeration air conditioner in which the refrigerant circuit is constituted by this heat source unit, during the heating operation, When the oil leveling operation becomes necessary, the operation of the oil leveling operation control device 222 provides the following operation. That is, the main heat source unit 1 and the sub heat source unit 10
The operation output of the main blower 6 and the auxiliary blower 106 is adjusted based on the low pressure detected by each heat source unit while keeping the operation output of the first unit as it is until the low pressure reaches a value at which the refrigerating machine oil can move between the heat source units. I do.

As a result, the refrigeration air conditioner quickly recovers its performance after the oil leveling operation due to the fact that the comfort and the performance during the oil leveling operation are less reduced and the operation output of each heat source unit does not change. In addition, the refrigerating machine oil returned from the use side heat exchanger 12 is equally distributed to the main heat source unit 1 and the sub heat source unit 101 by the oil equalizing operation of an appropriate frequency. Therefore, although detailed description is omitted, the same operation as the embodiment of FIGS. 1 to 7 can be obtained in the embodiment of FIGS.

Embodiment 5 FIG. 15 and 16 also show another example of the embodiment of the present invention. FIG. 15 is a refrigerant circuit diagram, and FIG. 16 is a flowchart for explaining control of the refrigerant circuit of FIG. The configuration of the refrigeration air conditioner, the flow of the refrigerant, and the flow of the refrigeration oil during normal operation are the same as those in the above-described embodiment of FIGS. 1 to 7, and the oil leveling operation is performed as described below. Will be In the figure, the same reference numerals as those in FIGS. 1 to 7, 13 and 14 denote the corresponding parts, and 23 denotes a flow control valve provided in a pipe line between the slave heat exchanger 105 and the liquid-side junction 14. , 24 are flow control valve adjusting means connected to the flow control valve 23.

In the refrigeration air conditioner configured as described above, the operation output of the main compressor 2 and the sub-compressor 102 remains unchanged regardless of the operation output of the main compressor 2 and the sub-compressor 102 during normal operation. , Low pressures in the main heat source unit 1 and the sub heat source unit 101 which are substantially equal to the internal pressures of the main oil reservoir 7 and the sub oil reservoir 107 are detected. The oil leveling operation is performed by adjusting the flow control valve 23 on the side of the sub heat source device 101 so that the internal pressure difference between the main oil reservoir 7 and the sub oil reservoir 107 through which the refrigerating machine oil can move through this detection can be secured. .

The above-described oil equalizing operation necessity determining means 20
When it is determined that the oil equalizing operation is necessary according to 2, the control according to the flowchart of FIG. 16 is performed. That is, in step 401, the operation time T of the main compressor 2 and the sub-compressor 102 is measured by the above-mentioned operation time measuring means 201.

Next, the routine proceeds to step 402, that is, to the oil equalizing operation necessity judging means 202. If the operating time T is shorter of the operable time Ta and the operable time Tb, that is, smaller than the operating time To, the process proceeds to step 401. Returning, if it is larger, the routine proceeds to step 403, where the oil leveling operation is performed. In step 404, the main low pressure detecting means 18 is used, and in step 405, the sub low pressure detecting means 11 is used.
In step 406, the low pressure of the corresponding heat source device is detected.

The first convergence judging means 19 moves the refrigerating machine oil from the main oil reservoir 7 to the auxiliary oil reservoir 107 regardless of the operation output of the main compressor 2 and the sub compressor 102 during the oil equalizing operation. Of the main oil reservoir 7 and the internal pressure P of the secondary oil reservoir 107
If the relationship of b is not Pa> Pb, the process proceeds to step 407, and if Pa> Pb, the process proceeds to step 408.

Then, in step 407, the flow control valve 23 is adjusted by the flow control valve adjusting means 24, and the flow returns to step 406. Also, in step 408, the convergence time timer 21 operates to proceed to step 409,
The time value T1 of the convergence time time counting means 21 is the compressor operation time T
If not larger, the process returns to step 408, and if larger, the process proceeds to step 410.

Then, at step 410, the secondary oil reservoir 107
If the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the secondary oil reservoir 107 of the second convergence determination means 20 is not Pa <Pb in order to move the refrigerating machine oil from the main oil reservoir 7 to If Pa <Pb, the process proceeds to step 412. As a result, in step 411, the flow control valve 23 is adjusted by the flow control valve adjusting means 24, and in step 410
Return to

In step 412, the convergence time timer 21 operates to proceed to step 413. If the time T1 of the convergence time timer 21 is not larger than the compressor operation time T, the process returns to step 412. 41
Proceeding to 4, the oil leveling operation ends.

Next, the flow of the refrigerating machine oil during the oil leveling operation will be described with reference to FIG. 15, together with the behavior of the refrigerant during the heating operation. That is, the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the secondary oil reservoir 107 of the first convergence determination means 19 during the heating operation is expressed as Pa> P.
b, when the refrigerating machine oil is moved from the main oil reservoir 7 to the auxiliary oil reservoir 107, the flow control valve 23 is gradually closed in order to reduce the internal pressure Pb of the auxiliary oil reservoir 107, and the secondary heat exchanger 1
The evaporation pressure of 05 is reduced.

At this time, the liquid-side merging section 14 passes through the use-side heat exchanger 12 and the use-side flow control valve 13 from the subordinate heat source unit 10.
The gas-liquid two-phase refrigerant branched to 1 is further reduced in pressure by closing the flow control valve 23. For this reason, since the pressure of the liquid-side merging portion 14 is larger than that of the main heat source unit 1 without the expansion device between the main heat exchanger 5 and the main heat exchanger 5, the evaporation pressure of the sub heat exchanger 105 is reduced. .

Along with this, the internal pressure Pb of the secondary oil reservoir 107 also drops below the internal pressure Pa of the main oil reservoir 7, and the refrigerating machine oil in the main oil reservoir 7 moves to the secondary oil reservoir 107. When the relationship between the internal pressure Pa of the main oil reservoir 7 and the internal pressure Pb of the secondary oil reservoir 107 of the second convergence determination means 20 is set to Pa <Pb, and the refrigerating machine oil is moved from the secondary oil reservoir 107 to the main oil reservoir 7. Then, the flow control valve 23 is gradually opened to increase the internal pressure Pa of the main oil reservoir 7, and the evaporation pressure of the sub heat exchanger 105 is increased.

At this time, the auxiliary heat source unit 10 is connected to the liquid side junction 14 via the use side heat exchanger 12 and the use side flow control valve 13.
The pressure drop of the gas-liquid two-phase refrigerant diverted to 1 becomes smaller than the pressure of the liquid-side merging portion 14 by opening the flow control valve 23. For this reason, the evaporation pressure in the sub heat exchanger 105 increases. Along with this, the internal pressure Pb of the secondary oil reservoir 107 also rises above the internal pressure Pa of the main oil reservoir 7, and the secondary oil reservoir 1
07 moves to the main oil reservoir 7.

In this manner, a large-capacity heat source means is formed by combining the main heat source unit 1 and the sub heat source unit 101, and in the refrigeration air conditioner in which the refrigerant circuit is constituted by this heat source unit, during the heating operation. When the oil equalizing operation becomes necessary, the operation output of the main heat source unit 1 and the sub heat source unit 101 is kept as it is, and based on the low pressure detected by each heat source unit, the respective low pressure moves the refrigerating machine oil between each heat source unit. The flow control valve 23 disposed between the sub heat exchanger 105 and the liquid-side merging section 14 is adjusted until the flow rate reaches a value that can be obtained.

As a result, the performance of the refrigeration air conditioner is quickly restored after the oil leveling operation due to the fact that the comfort and performance during the oil leveling operation are small and the operation output of each heat source unit does not change. In addition, the refrigerating machine oil returned from the use side heat exchanger 12 is equally distributed to the main heat source unit 1 and the sub heat source unit 101 by the oil equalizing operation of an appropriate frequency. Therefore, although detailed description is omitted, the same operation as the embodiment of FIGS. 1 to 7 can be obtained in the embodiment of FIGS.

[0116]

As described above, according to the present invention, a main compressor having a controllable output, a main oil separator, a main heat exchanger and a main heat source unit having a main oil reservoir, and a constant output or an output controllable. A secondary heat source unit having a secondary compressor, a secondary oil separator, a secondary heat exchanger and a secondary oil reservoir, a main heat source unit and a use side heat exchanger connected to the secondary heat source unit, a main heat source unit and a use side heat A liquid-side junction that connects a pipe line connected to an exchanger to a pipe line connected to a slave heat source unit and a use side heat exchanger, and a pipe line connected to a main heat source unit and a use side heat exchanger and a slave heat source unit A gas-side junction connecting the pipeline connecting the use-side heat exchanger, and a main oil reservoir and a secondary oil reservoir connected by an oil reservoir, and an opening of the oil reservoir on the main oil reservoir side. The portion is disposed at a position where the liquid in the main oil reservoir does not come into contact with the liquid in the main oil reservoir when the amount of the liquid in the main oil reservoir becomes equal to or less than the first predetermined amount. When the liquid amount in the secondary oil reservoir is less than or equal to the second predetermined amount, an oil equalizing circuit disposed at a position not in contact with the liquid in the secondary oil reservoir, and the compressor operating time of the main compressor and the secondary compressor is measured. Means for determining whether oil equalizing operation is necessary by comparing the operating time of the main compressor and the slave compressor by means of the compressor operating time measuring means with respect to the time TO in the above-mentioned formula 1. Are provided.

Thus, a large-capacity heat source means is formed by combining the main heat source unit and the auxiliary heat source unit, and in the refrigeration air conditioner in which the refrigerant circuit is constituted by this heat source unit,
Considering the deflection of the amount of oil returned to each heat source unit at the liquid-side junction and the gas-side junction, at the stage where the operation of each heat source unit has continued for a predetermined time, the oil leveling operation is determined by the oil leveling operation necessity determination means. Driving. Then, the refrigerating machine oil returned from the use-side heat exchanger is evenly distributed to the main heat source unit and the auxiliary heat source units by the oil equalizing operation of an appropriate frequency. Therefore, the comfort of frozen air conditioning,
Main compressor, without reducing the performance of refrigeration air conditioning,
This has the effect of improving the operational reliability of the slave compressor.

Further, as described above, the present invention is controlled by the oil equalizing operation necessity determining means of the oil equalizing operation necessity judging means, and the main compressor and the secondary compressor whose operation output alternately increases and decreases for a predetermined time. Is provided.

As a result, a large-capacity heat source means is formed by combining the main heat source unit and the auxiliary heat source unit. In the refrigeration air conditioner in which the refrigerant circuit is constituted by the heat source units,
Considering the deflection of the amount of oil returned to each heat source unit at the liquid side junction and the gas side junction, the operation of each heat source unit continues for a predetermined period of time, and the main oil equalization operation necessity determination unit determines The oil leveling operation for reversing the operation output difference between the heat source unit and the sub heat source unit for a predetermined time is performed.

Thus, the refrigerating machine oil returned from the use side heat exchanger is evenly distributed to the main heat source unit and the sub heat source unit by the oil equalizing operation of an appropriate frequency. Therefore, there is an effect of improving the operational reliability of the main compressor and the sub-compressor without deteriorating the comfort of the refrigeration air conditioning and the performance of the refrigeration air conditioning.

Further, as described above, the present invention is provided in the bypass circuit between the discharge part of the main compressor of the main heat source unit and the main oil reservoir, and the oil equalizing operation necessity of the oil equalizing operation necessity determining means is provided. A main opening / closing valve which is controlled through the determination and is opened for a predetermined time; and a leveling means which is provided in a bypass circuit between the discharge part of the secondary compressor and the secondary oil reservoir of the secondary heat source unit and which determines whether or not the oil leveling operation is necessary. And a secondary on-off valve that is controlled through the operation necessity determination and that closes when the primary on-off valve is opened.

Thus, a large-capacity heat source means is formed by combining the main heat source unit and the auxiliary heat source unit. In the refrigeration air-conditioning apparatus in which the heat source means constitutes a refrigerant circuit, the liquid-side junction and the gas-side junction are formed. Considering the deflection of the amount of oil returned to each heat source unit in the unit, the main circuit opening and closing valve of the bypass circuit, and the secondary opening and closing The valve is opened and closed alternately for a predetermined time.

Thus, the refrigerating machine oil returned from the use side heat exchanger is evenly distributed to the main heat source unit and the auxiliary heat source units by the oil equalizing operation of an appropriate frequency. Therefore, there is an effect of improving the operational reliability of the main compressor and the sub-compressor without deteriorating the comfort of the refrigeration air conditioning and the performance of the refrigeration air conditioning.

Further, as described above, the present invention provides a main low pressure detecting means provided on the main heat source unit, a sub low pressure detecting unit provided on the sub heat source unit, a main low pressure detecting unit, First convergence determination means that operates when the detection values of both of the secondary low pressure detection means converge to a first predetermined value, and second convergence determination that operates when the two detection values converge to a second predetermined value Means, convergence time timer means for measuring the convergence time by the first convergence determination means and the second convergence determination means, main blast output adjustment control means for controlling the blast output of the main blower of the main heat exchanger, and auxiliary heat exchange It operates through the auxiliary air output adjustment control means for controlling the air output of the auxiliary air blower of the blower and the oil equalization operation necessity determination of the oil equalization operation necessity determination means, and detects the main air blower and the auxiliary air blower output of the main low pressure pressure. Value detected through means and low pressure detection An oil-equalizing operation control device that operates the main ventilation output adjustment control unit and the secondary ventilation output adjustment control unit until the value detected through the stage converges to a predetermined value, and the time value of the convergence time timer reaches a predetermined time; Is provided.

As a result, a large-capacity heat source means is formed by combining the main heat source unit and the auxiliary heat source unit, and in the refrigeration air conditioner in which the refrigerant circuit is constituted by this heat source unit,
Considering the deflection of the amount of oil returned to each heat source unit at the liquid side junction and gas side junction, when the oil leveling operation is required during the heating operation, the operation of each heat source unit has continued for a predetermined time Through the determination of the oil equalization operation necessity determination means, the operation output of the main heat source unit and the sub heat source unit is kept as it is, and based on the low pressure detected by each heat source unit, the respective low pressure Adjust the blower output of the main blower and the slave blower until the value can be moved.

As a result, the comfort and performance during the oil leveling operation are less reduced, and the performance is quickly recovered after the oil leveling operation in combination with no change in the operation output of each heat source unit. The refrigerating machine oil returned from the vessel is equally distributed to the main heat source unit and the sub heat source unit by the oil equalizing operation of appropriate frequency. Therefore, there is an effect of improving the operational reliability of the main compressor and the sub-compressor without deteriorating the comfort of the refrigeration air conditioning and the performance of the refrigeration air conditioning.

Further, as described above, the present invention provides a main low pressure detecting means provided on the main heat source unit, a sub low pressure detecting unit provided on the sub heat source unit, a main low pressure detecting unit, First convergence determination means that operates when the detection values of both of the secondary low pressure detection means converge to a first predetermined value, and second convergence determination that operates when the two detection values converge to a second predetermined value Means, a convergence time measuring means for measuring convergence time by the first convergence determining means and the second convergence determining means, a flow control valve provided in a pipeline between the slave heat exchanger and the liquid side junction, Operates through the oil equalization operation necessity judgment means of the oil operation necessity judgment means, and the value detected by the flow control valve through the main low pressure detection means and the value detected through the secondary low pressure detection means converge to a predetermined value. Flow rate control until the time value of the convergence time It is provided with a flow control valve adjusting device for operating the valve.

As a result, a large-capacity heat source means is formed by combining the main heat source unit and the auxiliary heat source unit, and in the refrigeration air conditioner in which the refrigerant circuit is constituted by this heat source unit,
Considering the deflection of the amount of oil returned to each heat source unit at the liquid side junction and gas side junction, when the oil leveling operation is required during the heating operation, the operation of each heat source unit has continued for a predetermined time Through the determination of the oil equalizing operation necessity determination means, the operation output of the main heat source unit and the sub heat source unit is kept as it is, and based on the low pressure detected by each heat source unit, the respective low pressure Adjust the flow control valve disposed between the slave heat exchanger and the liquid-side junction until a value that can be moved is obtained.

As a result, the comfort and the performance during the oil leveling operation are less reduced, and the performance is quickly recovered after the oil leveling operation, in combination with the fact that there is no change in the operation output of each heat source unit. The refrigerating machine oil returned from the unit 12 is equally distributed to the main heat source unit and the slave heat source units by the oil equalizing operation of appropriate frequency.
Therefore, there is an effect of improving the operational reliability of the main compressor and the sub-compressor without deteriorating the comfort of the refrigeration air conditioning and the performance of the refrigeration air conditioning.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing Embodiment 1 of the present invention.

FIG. 2 is a graph conceptually showing an oil balance in the heat source unit of FIG.

FIG. 3 is a graph showing an oil balance relationship on the main heat source unit side related to FIG. 2;

FIG. 4 is a graph showing an oil balance relationship on the side of the subordinate heat source device related to FIG. 2;

FIG. 5 is an oil return circuit diagram relating to the oil balance of the refrigerant circuit of FIG. 1;

FIG. 6 is a graph showing an oil balance relationship with respect to a refrigerant circulation amount in the refrigerant circuit of FIG. 1;

FIG. 7 is a flowchart illustrating control of the refrigerant circuit of FIG. 1;

FIG. 8 is a graph showing a compressor operation output of an oil equalizing operation during a normal operation according to the second embodiment of the present invention.

FIG. 9 is a graph showing another compressor operation output related to FIG. 8;

FIG. 10 is a graph showing another compressor operation output related to FIG. 8;

FIG. 11 is a graph showing another compressor operation output related to FIG. 8;

FIG. 12 shows the third embodiment of the present invention, and is an oil return circuit diagram relating to the oil balance of the refrigerant circuit in the refrigeration air conditioner.

FIG. 13 is a refrigerant circuit diagram showing Embodiment 4 of the present invention.

FIG. 14 is a flowchart illustrating control of the refrigerant circuit of FIG. 13;

FIG. 15 is a refrigerant circuit diagram showing a fifth embodiment of the present invention.

FIG. 16 is a flowchart illustrating control on the refrigerant circuit of FIG. 15;

FIG. 17 is a refrigerant circuit diagram showing a conventional refrigeration air conditioner.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 main heat source unit, 2 main compressor, 3 main oil separator, 5 main heat exchanger, 6 main blower, 7 main oil reservoir, 101 auxiliary heat source unit, 102 auxiliary compressor, 103 auxiliary oil separator, 105
Secondary heat exchanger, 106 secondary blower, 107 secondary oil reservoir,
12 use side heat exchanger, 14 liquid side merging section, 15 gas side merging section, 16 oil equalizing circuit, 201 compressor operating time measuring means, 202 oil equalizing operation necessity determining means, 17 main open / close valve, 117 secondary open / close valve , 18 main low pressure detection means, 1
18 secondary low pressure detecting means, 19 first convergence determining means, 2
0 second convergence determination means, 21 convergence time clock means, 22
Main ventilation output adjustment control means, 122 secondary ventilation output adjustment control means, 222 oil leveling operation control device, 23 flow control valve,
24 Flow control valve adjusting means.

Claims (5)

[Claims] An output controllable main compressor, a main oil separator,
A main heat source unit having a main heat exchanger and a main oil reservoir, a sub compressor, a sub oil separator, a sub heat exchanger having a sub heat exchanger and a sub oil reservoir, and the main heat source unit and the sub heat source unit The connected use-side heat exchanger, and a liquid-side junction connecting the pipe connecting the main heat source unit and the use-side heat exchanger and the pipe connecting the slave heat source unit and the use-side heat exchanger. A gas-side junction connecting the pipe connecting the main heat source unit and the use-side heat exchanger to the pipe connecting the slave heat source unit and the use-side heat exchanger; the main oil reservoir and the slave oil The reservoir is connected by an oil reservoir line, and the main oil reservoir side opening of the oil reservoir line is provided in the main oil reservoir when the liquid amount in the main oil reservoir becomes equal to or less than a first predetermined amount. Is disposed at a position not in contact with the liquid, and the auxiliary oil reservoir side opening of the oil reservoir pipe is provided when the liquid amount in the auxiliary oil reservoir becomes equal to or less than a second predetermined amount. An oil equalizing circuit arranged at a position not in contact with the liquid in the oil reservoir, a compressor operating time measuring means of the main compressor and the auxiliary compressor, and the main compressor and the auxiliary compressor by the compressor operating time measuring means. A refrigeration air conditioner comprising: an oil equalizing operation necessity determining unit that determines whether oil equalizing operation is necessary by comparing an operation time of the machine with a time TO in the following equation. (Equation 1) Where χ: oil amount in oil reservoir ρ: oil density R5: amount of oil returned from oil reservoir to compressor R3: amount of oil returned from oil separator to oil reservoir 2. A main compressor and a sub-compressor whose operation output is alternately increased and decreased for a predetermined time, controlled by the oil equalizing operation necessity judging means by oil equalizing operation necessity judgment means. 2. The refrigerated air conditioner according to 1. 3. A predetermined time period, which is provided in a bypass circuit between a discharge portion of a main compressor of the main heat source unit and a main oil reservoir portion and is controlled via oil equalization operation necessity determination by oil equalization operation necessity determination means for a predetermined time. The main opening / closing valve to be opened and a bypass circuit provided between the discharge part and the auxiliary oil reservoir of the auxiliary compressor of the auxiliary heat source unit are controlled through the oil equalization operation necessity determination of the oil equalization operation necessity determination means. 2. The refrigeration air conditioner according to claim 1, further comprising a slave on-off valve that is closed when the main on-off valve is opened. 4. A main low pressure detecting means provided on the main heat source unit side, a low low pressure detecting unit provided on the sub heat source unit side, and both of the main low pressure detecting unit and the low low pressure detecting unit. A first convergence determining unit that operates when the detected value converges to a first predetermined value; a second convergence determining unit that operates when both of the detected values converge to a second predetermined value; Means and a convergence time measuring means for measuring a convergence time by the second convergence determining means, a main blower output adjusting control means for controlling a blower output of a main blower of a main heat exchanger, and a blower output of a slave blower of a slave heat exchanger. Operating through the auxiliary blower output adjustment control means and the oil equalization operation necessity determination means of the oil equalization operation necessity determination means, and detects the blower output of the main blower and the slave blower through the main low pressure detection means. And the detected value via the low pressure detection means And an oil-equalizing operation control device that operates the main airflow output adjustment control means and the auxiliary airflow output adjustment control means until the time value of the convergence time clocking means reaches a predetermined time. The refrigeration air conditioner according to claim 1, wherein: 5. A main low pressure detecting means provided on a main heat source unit side, a sub low pressure detecting unit provided on a sub heat source unit side, and both of the main low pressure detecting unit and the sub low pressure detecting unit. A first convergence determining unit that operates when the detected value converges to a first predetermined value; a second convergence determining unit that operates when both of the detected values converge to a second predetermined value; Means and a convergence time measuring means for measuring the convergence time by the second convergence determination means, a flow control valve provided in a pipe line between the slave heat exchanger and the liquid-side junction, and an oil equalization operation necessity determination means. Operated through the oil equalizing operation required judgment, the value detected by the main low pressure detection means and the value detected by the sub low pressure detection means of the flow control valve converge to a predetermined value, Operate the flow control valve until the time value of the convergence time timer reaches a predetermined time. 2. The refrigeration air conditioner according to claim 1, further comprising a flow control valve adjusting unit that operates.