CN102889712B - Multi-connected air-conditioning unit and oil balancing system thereof - Google Patents

Abstract

The invention provides an oil equalizing system of a multi-connected air conditioner unit. The outdoor unit includes at least two units; each unit includes at least two compressors, a gas-liquid separator, and an oil equalizing pipe. The group is connected to the suction port of each compressor, the exhaust port of each compressor is connected to each oil separator respectively and connected in parallel, and the oil discharge port of each oil separator is respectively connected to each suction pipe group; the oil equalizing pipe is connected to the Gas-liquid separator; the oil equalizing pipes of each unit are connected. The invention also provides a multi-connected air conditioner unit. The oil in the compressor is discharged to the oil equalizing pipe through the oil discharge port of each compressor in each unit, so that all the compressors in the unit participate in the oil equalization between the units, so that the oil between the outdoor units The amount is better balanced and the normal operation of the system is maintained.

Description

An oil equalizing system of a multi-connected air-conditioning unit and the multi-connected air-conditioning unit

technical field

The invention relates to the technical field of refrigeration, in particular to an oil equalizing system of a multi-connected air-conditioning unit and the multi-connected air-conditioning unit.

Background technique

In multi-connected air conditioning units, the air pipes, liquid pipes and oil equalizing pipes of each unit are usually connected to form a system. Figure 1 shows a schematic diagram of the composition of one unit, through the air pipes, liquid pipes and oil equalizing pipes The other units connected are not shown. Taking the system composed of two units as an example, see Figure 1. The oil equalization process of the system consists of two parts: the oil equalization between the compressors and the oil equalization between the units: (1) The first compressor A part of the oil discharged from the compressor 111 through the oil discharge port directly enters the second compressor 112 through the second suction pipe group 129, and the oil discharged from the second compressor 112 through the oil discharge port enters the second compressor 112 through the first suction pipe group 128. A compressor 111; (2) Another part of the oil discharged from the first compressor 111 through the oil discharge port enters the oil equalization pipe 121 through the oil discharge solenoid valve 119 and the oil discharge check valve 120, passes through the oil equalization cut-off valve 127, and is fed by another The oil equalizing cut-off valve 127 of one unit enters the oil suction solenoid valve 122, then the capillary 123, and then enters the gas-liquid separator 114 through the check valve 124, and enters the first compressor 111 and the second compressor respectively after being separated by the gas-liquid separator. Two compressors 112.

During this oil equalization process, the second compressor does not participate in the oil equalization among the units, so that the oil volume among the outdoor units cannot be well balanced, and it is easy to cause a unit in the system to lack oil, affecting the normal operation of the system.

Contents of the invention

In view of this, the present invention provides an oil equalization system of a multi-connected air conditioner unit and a multi-connected air conditioner unit, which solves the problem that the second compressor does not participate in the oil equalization between the units, so that the oil volume between the outdoor units is better To achieve balance and maintain the normal operation of the system.

The invention provides an oil equalization system of a multi-connected air conditioner unit, the outdoor unit includes:

at least two units;

Each unit includes: at least two compressors, a gas-liquid separator, and an oil equalizing pipe. The gas-liquid separator is connected to each compressor suction port through each suction pipe group, and each compressor exhaust port is connected to each The oil separators are connected in parallel, and the oil discharge ports of each oil separator are respectively connected to the respective suction pipe groups, or the oil discharge ports of each oil separator are respectively connected to or connected in parallel to the gas-liquid separator Each compressor oil discharge port is connected to the oil equalizing pipe through each oil drain pipe; the oil equalizing pipe is connected to the gas-liquid separator through an oil suction pipe; the oil equalizing pipes of each unit are connected.

Each compressor in each unit discharges the oil in the compressor to the oil equalizing pipe through its own oil discharge port. The oil in each unit is sucked into the gas-liquid separator, and the compressors in each unit suck the oil after gas-liquid separation into the compressor through their respective suction pipe groups, so that each compressor in each unit fully participates in the inter-unit The oil equalization makes the oil volume between the outdoor units better balance and maintains the normal operation of the system.

Wherein, in each unit, the oil discharge pipes connected to the oil discharge ports of the compressors are connected in parallel, and an oil discharge solenoid valve is connected to the oil equalizing pipe in series; The pipeline between them is connected to the gas-liquid separator through a pressure relief valve.

Through the oil discharge solenoid valve and the oil discharge check valve, it is beneficial for the oil in the compressor to flow into the oil equalizing pipe, and a pressure relief device is added to the oil circuit system to prevent the pressure of the oil circuit system from suddenly rising to the limit pressure of the system , causing the oil equalizing pipeline to rupture, protecting the oil equalizing pipeline.

Wherein, in each unit, an oil suction solenoid valve is connected in series on the oil suction pipe.

Through the oil suction solenoid valve, the oil equalization between the units can be realized, so that the oil quantity between the units can be balanced.

Wherein, the oil equalizing pipes of each unit are connected and arranged through the oil equalizing cut-off valve.

Through the oil equalizing cut-off valve, it is convenient to connect the oil equalizing pipeline between the units. It is beneficial to realize oil equalization among units.

Wherein, in each unit, each of the oil discharge pipes is connected in series with an oil discharge check valve.

Through the oil discharge check valve, it is beneficial to discharge the oil in the compressor to the oil equalizing pipeline.

Wherein, in each unit, an oil discharge check valve is connected in series on the pipeline between the oil discharge solenoid valve and the oil equalizing pipe.

Through the oil discharge check valve, it is beneficial to discharge the oil in the compressor to the oil equalizing pipeline.

Wherein, in each unit, an oil suction check valve is connected in series on the oil suction pipe.

Through the oil suction check valve, it is beneficial to achieve oil equalization among the units.

The present invention also provides a multi-connected air conditioner unit, which has any one of the above-mentioned oil equalization systems.

Each compressor in each unit discharges the oil in the compressor to the oil equalizing pipe through its own oil discharge port, and through the interconnected oil equalizing pipes, other units suck the oil in the oil equalizing pipes through the oil suction pipes connected to the oil equalizing pipes In the gas-liquid separator, the compressors of other units suck the oil after gas-liquid separation into the compressors through their respective suction pipe groups, so that each compressor in the unit participates in the oil equalization between the units, so that the outdoor The oil volume between the units is better balanced to maintain the normal operation of the system.

Description of drawings

Fig. 1 is a structural schematic diagram of an oil equalizing system of a multi-connected air-conditioning unit in the prior art;

Fig. 2 is a structural schematic diagram of an oil equalization system of a multi-connected air conditioner unit provided by the present invention.

Detailed ways

Embodiments of the present invention provide an oil equalization system of a multi-connected air conditioner unit and the multi-connected air conditioner unit. Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Referring to Fig. 2, the oil equalizing system provided by the embodiment of the present invention includes more than two sets of units, and Fig. 2 only shows a schematic diagram of the composition of one of the units: by connecting the oil equalizing shut-off valves of each set of units to each other, the unit connection between.

Each group of units includes at least two compressors. FIG. 2 shows a unit composed of two compressors, and the unit includes a first frequency conversion compressor 111 and a second frequency conversion compressor 112 .

The oil discharge port of the first frequency conversion compressor 111 is connected in series with the first oil discharge check valve 115 and then connected with the oil discharge pipe, such as the first oil discharge capillary 117, and the oil discharge port of the second frequency conversion compressor 112 is connected in series with the second oil discharge check valve After 116, connect the oil discharge pipe, such as the second oil discharge capillary 118, the pipeline after the parallel connection of the first oil discharge capillary 117 and the second oil discharge capillary 118 is connected with a parallel suction pipeline system and an oil equalizing pipeline system. The oil equalizing pipes in the oil equalizing pipeline systems of each unit are connected.

Each compressor in each unit discharges the oil in the compressor to the oil equalizing pipe through its own oil discharge port. The oil in each unit is sucked into the gas-liquid separator, and the compressors in each unit suck the oil after gas-liquid separation into the compressor through their respective suction pipe groups, so that each compressor in each unit fully participates in the inter-unit The oil equalization makes the oil volume between the outdoor units better balance and maintains the normal operation of the system.

In another example of the invention, each oil discharge pipe connected to the oil discharge port of each compressor in each unit can also be connected in series and an oil discharge solenoid valve is connected to the oil equalizing pipe, that is, it can also be connected in the oil equalizing pipeline system On the oil equalizing pipeline, the oil discharging electromagnetic valve 119, the oil discharging one-way valve 120, the oil equalizing pipeline 121 and the oil equalizing stop valve 127 arranged at the end of the oil equalizing pipeline are sequentially arranged in series.

Each compressor in each unit discharges the oil in the compressor to the oil equalization pipe through its own oil discharge port, and controls which unit supplies oil to other units through the oil discharge solenoid valve, so as to perform oil equalization to other units. For example, unit 1 can equalize oil to unit 2, open the oil discharge solenoid valve of unit 1, and close the oil discharge solenoid valve of unit 2, then only the compressors in unit 1 will discharge the oil in the compressor through their respective oil outlets. The oil is discharged to the oil equalizing pipe, and the oil suction pipe of unit 2 sucks the oil in the oil equalizing pipe into the gas-liquid separator of unit 2, and the compressor in unit 2 sucks and compresses the oil after gas-liquid separation through its own suction pipe group in the plane. After that, by controlling the oil discharge solenoid valve of the unit, unit 2 can equalize oil to unit 1.

The suction pipeline system includes a pressure relief valve 113 and a main suction pipe 125 connected in series. After the oil discharge pipes are connected in parallel, the pipeline between the oil discharge solenoid valves is connected to the gas-liquid separator through a pressure relief valve 113 .

The suction port of the first variable frequency compressor 111 sucks gas refrigerant from the gas-liquid separator 114 through the first suction pipe group 128, and the suction port of the second variable frequency compressor 112 passes through the second suction pipe group 129 from the gas-liquid separation. The device 114 sucks gas refrigerant.

The gas-liquid separator 114 communicates with a port of the four-way valve through the main suction pipe 125 . The port where the main suction pipe 125 communicates with the four-way valve is provided with a low-pressure pressure sensor 222, and the main suction pipe 125 is connected with the oil equalization pipeline 121 through the oil suction capillary line 123, and the oil suction capillary line 123 is provided with series oil suction lines. An air cut-off valve 126 is provided at the end of the pipeline where the one-way valve 124 communicates with the oil suction solenoid valve 122 and the other port of the four-way valve 310 .

The discharge port of the first variable frequency compressor 111 is connected with the inlet of the first oil separator 213 through the first high pressure switch 211, and the discharge port of the second variable frequency compressor 112 is connected with the second oil separator 216 through the second high pressure switch 216. The inlet of the separator 217 is connected, the outlet pipeline of the first oil separator 213 is connected in series with the first high pressure sensor 212 and the check valve, and the outlet pipeline of the second oil separator 217 is connected in series with the second high pressure sensor 215 and The one-way valves are connected in parallel, and the pipeline connected in parallel communicates with the other port of the four-way valve 310 . A solenoid valve 221 is provided on the pipeline from the parallel pipeline to the main suction pipe 125 .

The other port of the four-way valve 310 is connected to the inlet of the outdoor heat exchanger 311, and the outlet of the outdoor heat exchanger 311 can be connected to the auxiliary heat exchange through the parallel one-way valve 312 and the electronic expansion valve 313 respectively. The pipeline communicates with the liquid reservoir 315, and the outlet pipeline of the liquid reservoir 315 is connected in series with the regenerator 317 and the liquid pipe 318 in sequence. The outlet pipeline between the liquid storage 315 and the regenerator 317 communicates with the first suction pipe group 128 and the second suction pipe group 129 respectively through two pipelines, and the first suction pipe group 129 is respectively arranged on these two pipelines. An injection valve 219 and a second injection valve 220 .

The refrigeration and heating principle of the present invention is described below:

For the refrigeration process, the refrigerant in the indoor unit that has undergone depressurization and heat absorption enters the gas pipe 126, turns around through the four-way valve 310, and then enters the gas-liquid separator 114 for gas-liquid separation. The gas pipe group 128 and the second suction pipe group 129 respectively enter the first variable frequency compressor 111 and the second variable frequency compressor 112 for compression, and the compressed refrigerant becomes a high temperature and high pressure gas refrigerant, and then passes through the first variable frequency compressor 111 and the second variable frequency compressor. The exhaust port of the second inverter compressor 112 enters the first oil separator 213 and the second oil separator 217 respectively, and the separated oil passes through the oil return pipelines of the first oil separator 213 and the second oil separator 217 respectively And the first suction pipe group 128 and the second suction pipe group 129 connected with the oil return pipeline return to the first variable frequency compressor 111 and the second variable frequency compressor 112 . The oil discharge ports of each oil separator are respectively connected to the respective suction pipe groups. In this example, another implementation mode is also optional, that is, the oil discharge ports of each oil separator are respectively connected to or connected in parallel to the The gas-liquid separator. The separated refrigerant enters the outdoor unit system through the outlets of the first oil separator 213 and the second oil separator 217 for heat exchange. After passing through the outdoor heat exchanger 311, the cooled refrigerant enters the liquid accumulator 315 and becomes After the low-temperature and high-pressure refrigerant passes through the regenerator 317 to continue heat exchange and cooling, the refrigerant liquid enters the indoor unit through the liquid pipe to reduce pressure and absorb heat. After that, the refrigerant flows out of the indoor unit and enters the gas pipe 126 again for the next refrigerant cycle.

For the heating process, the cold medium in the indoor unit that has been depressurized and absorbed heat passes through the liquid pipe stop valve 318, passes through the high-pressure liquid reservoir 318, is throttled by the electronic expansion valve 313, enters the outdoor heat exchanger for heat exchange, and passes through the four After reversing through the reversing valve, it enters the main suction pipe 125 and then enters the gas-liquid separator 114. After the gas-liquid separation, the gaseous refrigerant enters the compressor 111 and the compressor 111 through the first suction pipe group and the second suction pipe group respectively. The suction port of the compressor 112, after being compressed by the compressor, the compressed refrigerant becomes a high-temperature and high-pressure gas refrigerant, and then enters the first oil separator through the exhaust ports of the first variable frequency compressor 111 and the second variable frequency compressor 112 respectively. 213 and the second oil separator 217, the separated oil respectively passes through the oil return pipeline of the first oil separator 213 and the second oil separator 217 and the first suction pipe group connected with the oil return pipeline 128 and the second suction pipe group 129 return to the first variable frequency compressor 111 and the second variable frequency compressor 112 . The oil discharge ports of each oil separator are respectively connected to the respective suction pipe groups. In this example, another implementation mode is also optional, that is, the oil discharge ports of each oil separator are respectively connected to or connected in parallel to the The gas-liquid separator. The separated refrigerant passes through the outlets of the first oil separator 213 and the second oil separator 217 and enters the air pipe shut-off valve 126 through the four-way reversing valve, enters the indoor unit for heat exchange, and the refrigerant after heat exchange passes through the liquid pipe shut-off valve again. 318. Enter the next heating cycle. When the exhaust temperature of the system is high, the solenoid valve 219 and the solenoid valve 220 can be used to unload the first suction pipe group and the second suction pipe group to prevent the unit from being shut down due to overheating.

The gas pipe cut-off valves and liquid pipe cut-off valves of each of the above-mentioned units are connected to each other through their own summarizing pipes, and the oil equalizing shut-off valves are connected to each other through the oil equalizing pipes, so as to realize the connection between units.

In addition, the pressure relief valve connected in series between the oil discharge one-way valve connected in series with each compressor in each group of units and the oil discharge solenoid valve on the oil equalizing pipeline is as follows:

Since the oil equalization between outdoor units is interval, it is necessary to carry out oil equalization between units at regular intervals. The oil check valve 115, the second oil discharge check valve 116 and the oil discharge solenoid valve form a closed space in which some liquid oil will be accumulated. The high-pressure and high-temperature gas makes the temperature of the oil in this closed space rise sharply, and the pressure also increases sharply in an instant, which can easily cause pipeline rupture, air leakage in the system, and directly cause the unit to fail to operate normally. A pressure relief device is added to the oil circuit system, that is, a pressure relief valve is connected through a section of copper pipe between the oil discharge check valve 1, oil discharge check valve 2, and oil discharge solenoid valve, and then passed through another section of copper pipe Connect to the main suction line on the low pressure side of the system. When the pressure of the oil circuit system suddenly rises to the limit pressure of the system, for example, 4.1MPa, the pressure relief device is opened, so that the high-pressure gas is discharged into the main suction pipe of the low-pressure side of the system, and the function of protecting the unit is realized. And when the pressure of the oil circuit system is relatively low, for example, when 3.6Mpa, the pressure relief valve is automatically closed.

The oil equalizing pipeline of each unit is connected with its total suction pipe group, and an oil suction solenoid valve and an oil suction check valve are arranged on the pipeline connected with the oil equalizing pipeline of each unit with its total suction pipe group. The total suction pipe group is connected with the suction pipe group of each compressor through a gas-liquid separator.

Next, the oil equalization principle of the oil equalization system of a multi-connected air conditioner unit provided by the embodiment of the present invention will be described:

Each unit of the present invention realizes the oil balance among the units through the oil equalizing pipeline between the units, so as to avoid excessive oil in a certain unit. In addition, the oil equalization between the units of this system is carried out by each unit separately. For example, firstly, unit 1 performs oil equalization. , the oil of each compressor in unit 1 enters the oil equalization pipeline of unit 2 through its oil equalizing pipeline, and then enters the inverter compressor of unit 2 through the oil suction solenoid valve of unit 2. After 15 minutes, unit 2 performs oil equalization, and each unit in unit 2 The oil of the compressor enters the oil equalizing pipeline of unit 1 through the oil equalizing pipeline, and then enters the inverter compressor of unit 1 through the oil suction solenoid valve of unit 1.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For example, modules with different functions can be realized through an integrated chip, etc., all within the spirit and principles of the present invention. Any modification, equivalent replacement, improvement, etc. shall be included in the protection scope of the present invention.

Claims (6)

1. an oil-balancing system for VRF Air Conditioning System, is characterized in that, off-premises station comprises:

At least two units;

Each unit comprises:

At least two compressors, a gas-liquid separator, oil equalizing pipes,

Described gas-liquid separator is connected to each compressor air suction mouth by each air intake duct group, and each exhaust outlet of compressor is connected in parallel after connecting each oil eliminator respectively,

The oil drain out of each oil eliminator is connected to each air intake duct group described respectively, or the oil drain out of each oil eliminator is connected to respectively or is connected to described gas-liquid separator after parallel connection,

Each compressor oil drainage mouth is connected to described oil equalizing pipe by each oil exit pipe;

Described oil equalizing pipe is connected to described gas-liquid separator by a fuel sucking pipe;

The oil equalizing pipe of each unit described is communicated with setting;

Further, in each unit,

Each oil exit pipe that described each compressor oil drainage mouth connects is connected an oil extraction check valve respectively, more in parallel after series connection one oil drain solenoid valve be connected to described oil equalizing pipe;

Pipeline after each oil exit pipe parallel connection described and between described oil drain solenoid valve is connected to total air intake duct of described gas-liquid separator connection by a pressure-relief valve.

2. oil-balancing system according to claim 1, is characterized in that, in each unit,

Described fuel sucking pipe also to be connected an oil suction magnetic valve.

3. oil-balancing system according to claim 1, is characterized in that, the oil equalizing pipe of each unit described is communicated with setting by equal oil cut-off valve.

4. oil-balancing system according to claim 1, is characterized in that, in each unit,

Described oil drain solenoid valve connects an oil extraction check valve that the pipeline between described oil equalizing pipe also connects.

5. oil-balancing system according to claim 1, is characterized in that, in each unit,

Described fuel sucking pipe also to be connected an oil sucting one-way valve.

6. a VRF Air Conditioning System, is characterized in that, has the oil-balancing system of the VRF Air Conditioning System described in arbitrary claim of claim 1 to 5.