CN110207419B

CN110207419B - Multi-split system

Info

Publication number: CN110207419B
Application number: CN201910554782.6A
Authority: CN
Inventors: 罗彬�; 杨坤; 占磊
Original assignee: Midea Group Co Ltd; GD Midea Heating and Ventilating Equipment Co Ltd
Current assignee: Midea Group Co Ltd; GD Midea Heating and Ventilating Equipment Co Ltd
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2022-03-29
Anticipated expiration: 2039-06-25
Also published as: CN110207419A

Abstract

The invention discloses a multi-online system, comprising: at least one indoor unit comprises a main heat exchange assembly and an auxiliary heat exchange assembly; an outdoor unit, comprising: a compressor having an exhaust port, a first suction port and a second suction port; the first reversing assembly comprises a first interface to a fourth interface; the second reversing component comprises a first valve port, a second valve port and a third valve port, and the third valve port is connected with the fourth interface; an outdoor heat exchanger; the first refrigerant flow path is connected with the first end of the main heat exchange assembly and the first end of the auxiliary heat exchange assembly respectively, the second end of the main heat exchange assembly is connected with the second end of the second refrigerant flow path, and the second end of the auxiliary heat exchange assembly is connected with the second end of the third refrigerant flow path. The multi-split system can avoid excessive indoor dehumidification, avoid the phenomenon of frequent start and stop of a room with small load, and improve the reliability and the operation energy efficiency of the system.

Description

Multi-split system

Technical Field

The invention relates to the technical field of air conditioning, in particular to a multi-split system.

Background

Currently, government and consumer energy efficiency requirements for air conditioning systems are increasing, and seasonal energy efficiency and operational energy savings are becoming a growing concern. In order to improve seasonal energy efficiency and actual operation energy efficiency, the energy-saving measures of an air-conditioning system, particularly a multi-split system, mainly include two types: firstly, directly improve the system efficiency, if adopt changeable refrigerant evaporating temperature, when system load is less, the evaporating temperature of refrigerant in the initiative rising system promotes the system efficiency. Secondly, the number of times of starting and stopping the system is reduced, the operation energy efficiency is improved, if a variable-capacity compressor is adopted, when the load is very low, the compressor is switched to be in a small capacity, the output of the system is further reduced, the evaporating temperature of a refrigerant in the system is improved, and the system starting and stopping are reduced to the greatest extent.

The two technologies can achieve a very good energy-saving effect in a one-to-one system, but in a multi-split system, the system must meet the refrigeration requirement of each room, and if the refrigeration requirement of a certain room is very large, the evaporation temperature of a refrigerant in the system cannot be adjusted upwards no matter what the refrigeration requirements of other rooms are. Therefore, the whole system runs in a low-energy-efficiency range, and other small-load room machines are frequently started and stopped. Specifically, if a room with a large load and a room with a small load exist in the multi-split air-conditioning system at the same time, the evaporation pressure of the refrigerant in the multi-split air-conditioning system needs to be adjusted to meet the requirement of the room with the large load, that is, the evaporation pressure of the refrigerant needs to be adjusted to be low, so that the output capacity of the indoor unit in the room with the large load can meet the requirement. At this time, the overall load of the system is relatively small, but the refrigerant in the multi-split system still needs to operate at a low evaporation pressure, and the energy efficiency of the system is low. Meanwhile, the room with small load can be frequently started and stopped due to the overlarge output capacity of the indoor unit.

Each indoor unit in a three-pipe multi-split air-conditioning system in the related art generally uses more than three rows of heat exchangers, and when the indoor units run pure refrigeration, heat exchange between a refrigerant and indoor return air is configured in a downstream mode. When the evaporation temperature of the refrigerant is fixed, the temperature difference between the indoor return air and the refrigerant in the first rows of heat exchangers in the indoor unit is large, and the heat exchange effect between the indoor return air and the refrigerant is good. However, after the heat exchangers in the front rows are cooled, the difference between the indoor return air temperature and the refrigerant evaporating temperature becomes smaller (the heat exchange temperature difference is usually less than three degrees), so that the last row of heat exchangers almost have no refrigeration effect, and the utilization rate is very low. And further influences the operation energy efficiency of the multi-split system.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, an object of the present invention is to provide a multi-split air conditioning system, which can avoid excessive dehumidification in a room, avoid frequent start and stop of a small-load room due to an excessive output capacity of an indoor unit to a certain extent, and improve reliability and operation energy efficiency of the multi-split air conditioning system.

The multi-split system according to an embodiment of the present invention includes: at least one indoor unit comprises a main heat exchange assembly and an auxiliary heat exchange assembly; an outdoor unit including: a compressor formed as a multi-cylinder compressor having a discharge port, a first suction port, and a second suction port; a first reversing component comprising a first port to a fourth port, the first port in communication with the exhaust port and the first port in communication with one of the second port and the third port, the fourth port in communication with the other of the second port and the third port and the fourth port in communication with the first intake port; a second direction changing assembly including first to fourth ports, the first port communicating with the exhaust port, the first port communicating with one of the second and third ports, the fourth port communicating with the other of the second and third ports, the fourth port communicating with the second suction port, the third port communicating with the fourth port, and a control valve connected between the third port and the fourth port; the first end of the outdoor heat exchanger is connected with the third interface; the first end of the first refrigerant flow path is connected with the second end of the outdoor heat exchanger, the first end of the second refrigerant flow path is connected with the second interface, the first end of the third refrigerant flow path is connected with the second valve port, the second end of the first refrigerant flow path is respectively connected with the first end of the main heat exchange assembly and the first end of the auxiliary heat exchange assembly, the second end of the main heat exchange assembly is connected with the second end of the second refrigerant flow path, and the second end of the auxiliary heat exchange assembly is connected with the second end of the third refrigerant flow path.

According to the multi-split system provided by the embodiment of the invention, the compressor is a multi-cylinder compressor, the compressor is provided with the first air suction port and the second air suction port, and the second reversing assembly and the third refrigerant flow path are arranged, so that the refrigeration, heating and constant-temperature dehumidification functions of the multi-split system can be ensured. When the multi-split air conditioner system is used for refrigerating, the indoor unit comprising the main heat exchange assembly and the auxiliary heat exchange assembly can have double evaporation temperatures, so that excessive indoor dehumidification can be avoided, the phenomenon that a room with a small load is frequently started and stopped due to overlarge output capacity of the indoor unit can be avoided to a certain extent, and the reliability and the operation energy efficiency of the multi-split air conditioner system can be improved.

According to some embodiments of the invention, the control valve is a check valve, and the control valve is configured to guide the refrigerant from the fourth port to the third port.

According to some embodiments of the invention, the control valve is an electronic expansion valve or a thermostatic expansion valve.

According to some embodiments of the invention, at least one of the first reversing assembly and the second reversing assembly is a four-way valve.

According to some embodiments of the present invention, at least one of the first refrigerant flow path to the third refrigerant flow path is provided with an on-off valve.

In some embodiments of the invention, the on-off valve is a solenoid valve or an electronic expansion valve.

According to some embodiments of the present invention, the outdoor unit further includes an outdoor throttling device, and two ends of the outdoor throttling device are respectively connected to the second end of the outdoor heat exchanger and the first end of the first refrigerant flow path.

According to some embodiments of the invention, the compressor comprises a twin-cylinder compressor.

According to some embodiments of the invention, the compressor comprises a first compressor having a first discharge port and the first suction port and a second compressor having a second discharge port and the second suction port, the first discharge port and the second discharge port together constituting the discharge port.

According to some embodiments of the present invention, the outdoor unit includes a plurality of fans which are independent of each other and are arranged in sequence in a flow direction of the air current.

According to some embodiments of the present invention, the outdoor unit further includes an oil separator, the oil separator includes an inlet, an outlet, and an oil return port, the inlet is connected to the exhaust port, the outlet is connected to the first port and the first valve port, the oil return port is connected to the first suction port and/or the second suction port, and a capillary tube and/or a filter is disposed between the oil return port and the compressor.

According to some embodiments of the invention, the outdoor unit further comprises a gas-liquid separator including a gas-liquid inlet connected to the fourth port and a gas outlet connected to the first suction port.

According to some embodiments of the present invention, the main heat exchange assembly includes a main heat exchanger and a main throttling device, which are arranged in series, the auxiliary heat exchange assembly includes an auxiliary heat exchanger and an auxiliary throttling device, which are arranged in series, the main throttling device is located between the main heat exchanger and the first refrigerant flow path, the auxiliary throttling device is located between the auxiliary heat exchanger and the first refrigerant flow path, and the main throttling device and the auxiliary throttling device are respectively formed as electronic expansion valves.

According to some embodiments of the invention, the multi-split system is a tri-pipe multi-split system.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic diagram of a multi-split system according to some embodiments of the present invention.

Reference numerals:

a multi-split system 100;

an indoor unit 1;

a primary heat exchange assembly 11; a main heat exchanger 111; a primary throttle device 112;

an auxiliary heat exchange assembly 12; an auxiliary heat exchanger 121; a secondary flow restriction 122;

an outdoor unit 2;

a compressor 21; an exhaust port 211; a first air intake port 212; a second inlet port 213;

a first reversing component 22; a first interface 221; a second interface 222; the third interface 223; a fourth interface 224;

a second reversing component 23; the first valve port 231; a second valve port 232; a third valve port 233; a fourth valve port 234;

an outdoor heat exchanger 24;

an oil separator 25; an inlet 251; an outlet 252; an oil return port 253; a capillary 25 a; a filter 25 b;

a gas-liquid separator 26; a gas-liquid inlet 261; a gas outlet 262;

an outdoor throttle device 27;

a fan 28;

a control valve 3; an on-off valve 4;

a first refrigerant flow path a; a second refrigerant passage b; and a third refrigerant passage c.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

A multi-split system 100 according to an embodiment of the present invention is described below with reference to fig. 1. The multi-split system 100 may be a three-pipe multi-split system 100.

As shown in fig. 1, a multi-split system 100 according to an embodiment of the present invention includes: a plurality of indoor units 1, an outdoor unit 2, and first to third refrigerant flow paths a to c.

Specifically, at least one indoor unit 1 includes a main heat exchange assembly 11 and an auxiliary heat exchange assembly 12. That is, at least one indoor unit 1 has two heat exchange portions.

The outdoor unit 2 includes: the compressor 21, the first reversing assembly 22, the second reversing assembly 23 and the outdoor heat exchanger 24. The compressor 21 is a multi-cylinder compressor 21, and the compressor 21 has an exhaust port 211, a first intake port 212, and a second intake port 213. This improves the compression capacity of the compressor 21 for the refrigerant, and it can be seen that the compressor 21 has two suction ports, i.e., the first suction port 212 and the second suction port 213, so that the refrigerant pressures at the first suction port 212 and the second suction port 213 can be made different.

The first direction switching assembly 22 includes first to fourth ports 221 to 224, the first port 221 communicating with the exhaust port 211, and the first port 221 communicating with one of the second port 222 and the third port 223, the fourth port 224 communicating with the other of the second port 222 and the third port 223, and the fourth port 224 communicating with the first intake port 212. A first end of the outdoor heat exchanger 24 is connected to the third port 223. The second direction changing assembly 23 includes first to fourth ports 231 to 234, the first port 231 communicates with the exhaust port 211, the first port 231 communicates with one of the second and

third ports

232 and 233, the fourth port 234 communicates with the other of the second and

third ports

232 and 233, the fourth port 234 communicates with the second suction port 213, the third port 233 is connected to the fourth port 224, and the control valve 3 is connected between the third port 233 and the fourth port 224. Therefore, when the control valve 3 is opened, the third port 233 may communicate with the fourth port 224, and when the control valve 3 is closed, the third port 233 and the fourth port 224 are not communicated with each other, and the refrigerant may not pass through.

A first end of the first refrigerant flow path a is connected to a second end of the outdoor heat exchanger 24, a first end of the second refrigerant flow path b is connected to the second port 222, a first end of the third refrigerant flow path c is connected to the second valve port 232, a second end of the first refrigerant flow path a is connected to a first end of the main heat exchange assembly 11 and a first end of the auxiliary heat exchange assembly 12, a second end of the main heat exchange assembly 11 is connected to a second end of the second refrigerant flow path b, and a second end of the auxiliary heat exchange assembly 12 is connected to a second end of the third refrigerant flow path c.

As can be seen from the above, when the multi-split system 100 according to the embodiment of the present invention performs cooling, the first port 221 and the third port 223 may be controlled to communicate with each other, the first port 231 and the third port 233 may communicate with each other, and the control valve 3 may be closed. At this time, the third port 233 is not communicated with the fourth port 224, the refrigerant cannot flow, the second port 222 is communicated with the fourth port 224, and the second port 232 is communicated with the fourth port 234. After the high-temperature and high-pressure gaseous refrigerant in the compressor 21 is discharged from the discharge port 211, the refrigerant flows toward the outdoor heat exchanger 24 along the first port 221 and the third port 223, and condenses and releases heat when flowing through the outdoor heat exchanger 24, and the refrigerant after heat exchange flows toward the indoor unit 1 along the first refrigerant flow path a, wherein a part of the refrigerant flows through the main heat exchange assembly 11 to absorb heat by evaporation, and the other part of the refrigerant flows through the auxiliary heat exchange assembly 12 to absorb heat by evaporation.

It should be noted that, in the embodiment of the present invention, each heat exchange assembly is provided with a throttling device, so that the refrigerant flowing to the main heat exchange assembly 11 can be throttled and depressurized by the throttling device to form a gas-liquid mixed refrigerant with an evaporation pressure, then is evaporated and absorbs heat in a heat exchanger in the main heat exchange assembly 11, and is formed into a gaseous refrigerant after heat exchange, and flows to the first reversing assembly 22 along the second refrigerant flow path b, then sequentially flows through the second interface 222 and the fourth interface 224, and finally flows back to the compressor 21 through the first air suction port 212 of the compressor 21. The refrigerant flowing to the auxiliary heat exchange assembly 12 may be throttled and depressurized by the throttling device to form a gas-liquid mixed refrigerant with another evaporation pressure, and then evaporated and absorbed heat in the heat exchanger in the auxiliary heat exchange assembly 12, and the refrigerant formed into a gaseous state after heat exchange flows to the second reversing assembly 23 along the third refrigerant flow path c, then sequentially flows through the second valve port 232 and the fourth valve port 234, and finally flows back to the compressor 21 through the second suction port 213 of the compressor 21.

Therefore, the evaporating pressure of the refrigerant in the main heat exchange assembly 11 and the evaporating pressure of the refrigerant in the auxiliary heat exchange assembly 12 can be different, that is, the evaporating temperature of the refrigerant in the main heat exchange assembly 11 and the evaporating temperature of the refrigerant in the auxiliary heat exchange assembly 12 can be different. Therefore, when the load in the room where the indoor unit 1 including the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 in the multi-split system 100 of the embodiment of the present invention is located is large, both the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 may be controlled to be turned on (which may be controlled by respective throttling devices), the evaporation pressure of the refrigerant in the main heat exchange assembly 11 is controlled to be relatively large, and the evaporation pressure of the refrigerant in the auxiliary heat exchange assembly 12 is controlled to be relatively small, so that the air entering the indoor unit 1 first exchanges heat with the main heat exchange assembly 11 having the large evaporation pressure of the refrigerant, and further the air is primarily cooled. Then the primarily cooled air exchanges heat with the auxiliary heat exchange assembly 12 to realize further cooling. It should be noted that the primary heat exchange assembly 11 is located upstream of the secondary heat exchange assembly 12 in the flow direction of the gas flow.

Therefore, the multi-split system 100 according to the embodiment of the present invention realizes gradient configuration of refrigerant evaporation pressure (the refrigerant in the main heat exchange assembly 11 has a larger evaporation pressure, and the refrigerant in the auxiliary heat exchange assembly 12 has a smaller evaporation pressure), the main heat exchange assembly 11 having the higher evaporation pressure of the refrigerant first contacts with the air entering the indoor unit 1 to cool the indoor return air having a higher temperature, and the auxiliary heat exchange assembly 12 having the lower evaporation pressure of the refrigerant further cools the outlet air of the main heat exchange assembly 11 having the lower temperature. Therefore, the refrigerant of the indoor unit 1 has double evaporation temperatures, and the refrigeration requirement in a large-load room can be realized.

It can be understood that, although the evaporating pressure of main heat exchange assembly 11 is great, the evaporating temperature of refrigerant is higher promptly, and then make the difference in temperature between refrigerant and the indoor return air a little relatively, but this moment because the difference in temperature itself between the evaporating temperature of refrigerant and the indoor temperature is great, thereby it is not obvious to the heat transfer performance influence of indoor set 1, and the evaporating pressure of the supplementary heat exchange assembly 12 that is located the low reaches is less, thereby the evaporating temperature that makes the refrigerant is lower relatively, compare with the refrigerant in main heat exchange assembly 11 from this, the difference in temperature between the refrigerant of assisting in the heat exchange assembly 12 and the air after the cooling of main heat exchange assembly 11 can increase, because this moment the heat transfer difference in temperature itself is less, so the increase difference in temperature promotes very obviously to heat transfer capacity. Therefore, the auxiliary heat exchange assembly 12 can effectively cool the air flow.

Therefore, in the multi-split system 100 according to the embodiment of the present invention, the evaporation pressure gradient configuration of the refrigerant in the indoor unit 1 effectively increases the heat exchange temperature difference between the refrigerant and the air in the auxiliary heat exchange assembly 12, and increases the heat exchange efficiency of the auxiliary heat exchange assembly 12. Thus, in the multi-split system 100, the large load demand can be still satisfied in the case where the integrated evaporation pressure is high. Therefore, the energy efficiency during multi-split air conditioning can be effectively improved.

It can be understood that, when the load in the room where the indoor unit 1 including the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 is located in the multi-split air-conditioning system 100 according to the embodiment of the present invention is small, the main heat exchange assembly 11 may be controlled to be turned on, and the auxiliary heat exchange assembly 12 may be controlled to be turned off (by respective throttling devices), so that the refrigeration output may be realized only by the main heat exchange assembly 11 with a higher evaporation pressure of the refrigerant, and thus the energy efficiency of the multi-split air-conditioning system 100 may be effectively improved, and meanwhile, the phenomenon of frequent start and stop due to an overlarge output capability of the indoor unit 1 in the room with a small load may be avoided to a certain extent, so that the reliability of the multi-split air-conditioning system 100 may be improved, and the service life of the multi-split air-conditioning system 100 may be prolonged.

Therefore, in the multi-split system 100 according to the embodiment of the present invention, the evaporation temperature of the indoor unit 1 may be controlled to match the preset temperature of the room, the room with a small load uses the refrigerant with a high evaporation temperature, and the room with a large load additionally provides the refrigerant with a low evaporation temperature, so that the indoor unit 1 with a low load in the system can operate in a higher energy efficiency interval, the system start and stop are reduced, and the overall energy efficiency is improved.

When the multi-split system 100 according to the embodiment of the present invention dehumidifies, the first port 221 and the third port 223 may be controlled to communicate with each other, the first port 231 and the second port 232 may communicate with each other, and the control valve 3 may be opened. At this time, the third port 233 is communicated with the fourth port 224, the refrigerant can smoothly flow through, the second port 222 is communicated with the fourth port 224, and the third port 233 is communicated with the fourth port 234. After the high-temperature and high-pressure gaseous refrigerant in the compressor 21 is discharged from the discharge port 211, a portion of the refrigerant may flow toward the outdoor heat exchanger 24 along the first port 221 and the third port 223, and condense and release heat while flowing through the outdoor heat exchanger 24, the refrigerant after heat exchange is formed into a high-pressure liquid refrigerant and flows toward the main heat exchange assembly 11 of the indoor unit 1 along the first refrigerant flow path a, another portion of the refrigerant may sequentially flow through the first valve port 231 and the second valve port 232, and then flows to the auxiliary heat exchange assembly 12 along the third refrigerant flow path c to condense and release heat, the refrigerant after heat exchange is formed into a high-pressure liquid refrigerant and flows toward the main heat exchange assembly 11, the two paths of the refrigerant are throttled and depressurized by the throttling device in the main heat exchange assembly 11, and then undergo evaporation and heat absorption in the heat exchanger in the main heat exchange assembly 11, the refrigerant after heat exchange is formed into a gaseous refrigerant and flows to the first reversing assembly 22 along the second refrigerant flow path b, then flows through the second port 222 and the fourth port 224 in sequence, then a portion of the refrigerant directly flows back to the compressor 21 through the first suction port 212, and another portion of the refrigerant flows through the control valve 3, the third port 233 and the fourth port 234 in sequence, and then flows back to the compressor 21 through the second suction port 213.

As is known, the refrigerant evaporates and absorbs heat in the main heat exchange assembly 11, that is, the main heat exchange assembly 11 performs cooling. The refrigerant condenses in assisting heat exchange assembly 12 and releases heat, and assist heat exchange assembly 12 to heat promptly to the steerable indoor return air of multi-split air system 100 is at first through main heat exchange assembly 11, and then the refrigerant in the main heat exchange assembly 11 can carry out the heat transfer with the air in order to reduce the temperature of air, makes the temperature of the vapor in the air reach below the dew point, and then makes the vapor can condense into liquid water, can reduce the humidity of air from this, reaches the purpose of dehumidification. Knowing that the temperature of the air after heat exchange by the main heat exchange assembly 11 is reduced, the multi-split air system 100 enables the air after heat exchange with the main heat exchange assembly 11 to flow through the auxiliary heat exchange assembly 12 again to exchange heat with the auxiliary heat exchange assembly 12, and then the temperature of the air can be increased. Therefore, the constant-temperature dehumidification function of the multi-split air conditioning system 100 is realized, and the comfort of users is improved. Thereby, the multi-split system 100 according to the embodiment of the present invention may be used in an environment where the indoor temperature is not high but the humidity is high in some seasons (e.g., plum rain season).

It can be understood that, when the multi-split air conditioning system 100 according to the embodiment of the present invention operates, the air flow entering the indoor unit 1 first flows through the auxiliary heat exchange assembly 12 to exchange heat and raise the temperature, and then flows through the main heat exchange assembly 11 to exchange heat and lower the temperature and dehumidify (at this time, the temperature needs to be lowered below the dew point), the air discharged into the room is still low-temperature air, and the purpose of constant-temperature dehumidification cannot be achieved. Therefore, when dehumidification is performed by using the multi-split air conditioning system 100 according to the embodiment of the present invention, it is necessary to control the direction of indoor return air, so that the airflow entering the indoor unit 1 sequentially flows through the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 (for example, when the indoor unit 1 is produced, the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 are sequentially arranged in the flowing direction of the airflow), even if the air is first cooled, the water vapor is condensed into liquid, and then the temperature of the dehumidified air is raised, so that the air with constant temperature and dryness can be obtained, and the purpose of constant temperature dehumidification is achieved.

When the multi-split system 100 according to the embodiment of the present invention heats, the first port 221 and the second port 222 may be controlled to communicate with each other, the first port 231 and the second port 232 may communicate with each other, and the control valve 3 may be opened. At this time, the third port 233 is communicated with the fourth port 224, the refrigerant can smoothly flow through, the third port 223 is communicated with the fourth port 224, and the third port 233 is communicated with the fourth port 234. After the high-temperature and high-pressure gaseous refrigerant in the compressor 21 is discharged from the discharge port 211, a portion of the refrigerant may sequentially flow through the first port 221 and the second port 222, and then flow to the main heat exchange assembly 11 along the second refrigerant flow path b to perform condensation heat release, the refrigerant after heat exchange may be formed into a high-pressure liquid refrigerant and flow toward the outdoor heat exchanger 24 along the first refrigerant flow path a, another portion of the refrigerant may sequentially flow through the first valve port 231 and the second valve port 232, and then flow to the auxiliary heat exchange assembly 12 along the third refrigerant flow path c to perform condensation heat release, and the refrigerant after heat exchange is formed into a high-pressure liquid refrigerant and flow toward the outdoor heat exchanger 24 along the first refrigerant flow path a. It can be understood that, at this time, the outdoor unit 2 should have a throttling device, so that the high-pressure liquid refrigerant flowing towards the outdoor heat exchanger 24 can flow through the outdoor heat exchanger 24 to absorb heat by evaporation after being throttled and depressurized by the throttling device in the outdoor unit 2, and the refrigerant that is formed into a gaseous state after heat exchange flows through the third interface 223 and the fourth interface 224 in sequence, then a part of the refrigerant directly flows back to the compressor 21 through the first suction port 212, and another part of the refrigerant flows through the control valve 3, the third valve port 233 and the fourth valve port 234 in sequence, and then flows back to the compressor 21 through the second suction port 213. Thereby implementing the heating function of the multi-split air conditioning system 100.

In summary, the multi-split air-conditioning system 100 according to the embodiment of the present invention may be a three-pipe multi-split air-conditioning system 100, and has the functions of cooling, heating and dehumidifying at a constant temperature. Meanwhile, when refrigeration is carried out, the indoor unit 1 comprising the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 can have double evaporation temperatures, the system energy efficiency can be effectively improved, indoor transitional dehumidification is avoided to a certain extent, the phenomenon that a room with small load is frequently started and stopped due to overlarge output capacity of the indoor unit 1 is avoided to a certain extent, the reliability and the operation energy efficiency of the multi-split system 100 can be improved, and the service life of the multi-split system 100 can be prolonged.

According to the multi-split system 100 of the embodiment of the invention, the compressor 21 is a multi-cylinder compressor 21, the compressor 21 has the first suction port 212 and the second suction port 213, and the second reversing assembly 23 and the third refrigerant flow path c are provided, so that the cooling, heating and constant temperature dehumidification functions of the multi-split system 100 can be ensured. When the multi-split air conditioner system 100 is used for refrigerating, the indoor unit 1 comprising the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 can have double evaporation temperatures, so that indoor transitional dehumidification can be avoided, the phenomenon that a room with a small load is frequently started and stopped due to overlarge output capacity of the indoor unit 1 can be avoided to a certain extent, and the reliability and the operation energy efficiency of the multi-split air conditioner system 100 can be improved.

According to some embodiments of the present invention, the outdoor unit 2 further includes an oil separator 25, the oil separator 25 includes an inlet 251, an outlet 252, and an oil return port 253, the inlet 251 is connected to the discharge port 211, the outlet 252 is connected to the first port 221 and the first valve port 231, respectively, and the oil return port 253 is connected to the first suction port 212 and/or the second suction port 213. That is, the oil return port 253 may be connected to only the first suction port 212, only the second suction port 213, or both the first suction port 212 and the second suction port 213. The production design can be flexibly selected according to the actual situation. The oil separator 25 can separate the refrigerant gas from the lubricating oil, the separated refrigerant gas is discharged through the outlet 252 and flows to the first reversing assembly 22 and the second reversing assembly 23, and the separated lubricating oil can flow back to the compressor 21 through the oil return port 253, the first air suction port 212 and/or the second air suction port 213, so that the recycling of the lubricating oil can be realized.

In some embodiments of the present invention, a capillary tube 25a is provided between the oil return port 253 and the compressor 21. The capillary tube 25a is known to have a throttling function, so that the medium (lubricant oil or gaseous refrigerant mixed in the lubricant oil) flowing from the oil return port 253 to the compressor 21 can be throttled and depressurized, and the medium can smoothly flow back to the compressor 21.

In some embodiments of the present invention, a filter 25b is disposed between the oil return port 253 and the compressor 21. Therefore, the filter 25b can effectively filter the lubricating oil flowing back to the compressor 21, and effectively prevent solid residues (such as metal debris residues left inside during production of the oil separator 25 or a flow pipeline of the lubricating oil) and the like in the lubricating oil from flowing back to the compressor 21 along with the lubricating oil, thereby being beneficial to improving the use reliability of the compressor 21 and improving the reliability of the multi-split system 100.

In some implementations of the invention, both capillary tube 25a and filter 25b may be provided between oil return 253 and compressor 21. Therefore, the medium (lubricating oil or gaseous refrigerant mixed in the lubricating oil) flowing from the oil return port 253 to the compressor 21 can be throttled and depressurized, and the medium can smoothly flow back to the compressor 21. And the lubricating oil flowing back to the compressor 21 can be effectively filtered, so that solid slag (such as metal debris left inside during production of the oil separator 25 or a flow pipeline of the lubricating oil) and the like mixed in the lubricating oil are effectively prevented from flowing back to the compressor 21 along with the lubricating oil, and the use reliability of the compressor 21 and the reliability of the multi-split system 100 are improved. In this case, the capillary tube 25a and the filter 25b are provided in series between the oil return port 253 and the compressor 21. Here, the capillary tube 25a may be provided downstream of the filter 25b, and the capillary tube 25a may be provided upstream of the filter 25b in the flow direction of the lubricating oil.

According to some embodiments of the present invention, the outdoor unit 2 further includes a gas-liquid separator 26, the gas-liquid separator 26 includes a gas-liquid inlet 261 and a gas outlet 262, the gas-liquid inlet 261 is connected to the fourth port 224, and the gas outlet 262 is connected to the first suction port 212. Thereby ensuring a normal operation of the compressor 21. Specifically, the refrigerant after heat exchange is returned to the compressor 21 and compressed again, thereby ensuring the recycling of the refrigerant. Generally, the refrigerant after heat exchange is in a gas-liquid two-phase state, and the compression ratio of the liquid refrigerant is very low, so that the power component of the compressor 21 is easily damaged after the liquid refrigerant enters the compressor 21. The gas-liquid separator 26 is arranged to separate gaseous and liquid refrigerants. After the gas-liquid two-phase refrigerant enters the gas-liquid separator 26, the gas-liquid separator 26 may separate the gas-phase refrigerant and discharge the gas-phase refrigerant from the gas outlet 262, and finally flow back to the compressor 21 through the first suction port 212, and the liquid-phase refrigerant separated by the gas-liquid separator 26 is stored in the gas-liquid separator 26.

According to some embodiments of the present invention, the control valve 3 is a one-way valve, and the control valve 3 is used for guiding the refrigerant from the fourth port 224 to the third port 233. It can be seen that the control valve 3 has a simple structure and low cost, and can ensure that the refrigerant can flow from the fourth port 224 to the third port 233, and prevent the refrigerant from flowing from the third port 233 to the fourth port 224. And thus, the reliability of the multi-split system 100 can be improved.

According to some embodiments of the invention, the control valve 3 is an electronic expansion valve or a thermostatic expansion valve. That is, the control valve 3 not only has a function of opening and closing the flow path between the third port 233 and the fourth port 224, but also can reduce the pressure by throttling. Thereby improving the reliability of the control valve 3 and contributing to the improvement of the reliability of the multi-split system 100. Alternatively, the control valve 3 may be a solenoid valve.

According to some embodiments of the present invention, at least one of the first reversing assembly 22 and the second reversing assembly 23 is a four-way valve. Therefore, in the embodiment of the present invention, one of the first reversing component 22 and the second reversing component 23 may be a four-way valve, and both the first reversing component 22 and the second reversing component 23 may also be four-way valves. The known four-way valve has the characteristics of low cost, simple structure, sensitive reaction and high working reliability. Thereby making the multi-split system 100 low in cost and high in reliability.

According to some embodiments of the present invention, at least one of the first to third refrigerant passages a to c is provided with an on-off valve 4. Therefore, when the refrigerant is charged into the compressor 21, the on-off valve 4 is closed to prevent the refrigerant from flowing directly to the indoor unit 1. The production efficiency of the multi-split system 100 is improved, and the reliability of the multi-split system 100 is improved.

In some embodiments of the invention, the on-off valve 4 is a solenoid valve or an electronic expansion valve. Therefore, the switch valve 4 not only has the function of conducting or cutting off the refrigerant flow path, but also has the function of throttling and reducing pressure.

According to some embodiments of the present invention, there are three indoor units 1, and two of the indoor units 1 include a main heat exchange assembly 11 and an auxiliary heat exchange assembly 12. Therefore, the energy efficiency of the multi-split system 100 can be further improved, and the reliability of the multi-split system can be improved. Under the condition that the loads of different rooms of two indoor units 1 including the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 are different, the main heat exchange assembly 11 and the auxiliary heat exchange assembly 12 of the indoor unit 1 in the room with the large load can be opened, and the indoor unit 1 in the room with the small load only opens the main heat exchange assembly 11. Therefore, the energy efficiency of the multi-split system 100 can be improved, and the frequent start-stop phenomenon of the indoor unit 1 can be reduced. Alternatively, another of the three indoor units 1 may have only one heat exchanger and one throttling device, whereby the normal heat exchange function of the indoor unit 1 may be ensured.

According to some embodiments of the present invention, the primary heat exchange assembly 11 comprises a primary heat exchanger 111 and a primary throttling device 112 arranged in series, and the secondary heat exchange assembly 12 comprises a secondary heat exchanger 121 and a secondary throttling device 122 arranged in series. Therefore, the reliability of the refrigerant flowing in the flow path of the multi-split system 100 can be ensured, and the multi-split system 100 can be operated reliably. The indoor unit 1 is ensured to have double evaporation temperatures during refrigeration.

In some embodiments of the present invention, the main throttle device 112 is located between the main heat exchanger 111 and the first refrigerant flow path a. Therefore, when the multi-split air conditioning system 100 is used for cooling, the main throttling device 112 may throttle and depressurize the refrigerant flowing into the main heat exchange assembly 11, and then evaporate and absorb heat at the main heat exchanger 111. The reliability of the multi-split system 100 is guaranteed.

In some embodiments of the present invention, the auxiliary throttling device 122 is located between the auxiliary heat exchanger 121 and the first refrigerant flow path a. Therefore, when the multi-split system 100 is used for refrigeration, the auxiliary throttling device 122 may throttle and depressurize the refrigerant flowing into the auxiliary heat exchange assembly 12, and then evaporate and absorb heat at the auxiliary heat exchanger 121. The reliability of the multi-split system 100 is guaranteed.

In some embodiments of the present invention, the primary throttle device 112 and the secondary throttle device 122 are each formed as an electronic expansion valve. Therefore, the main throttling device 112 and the auxiliary throttling device 122 can be ensured to not only have the functions of conducting or cutting off the refrigerant flow path, but also have the functions of throttling and reducing pressure. So that the reliability of the operation of the multi-split system 100 can be ensured.

According to some embodiments of the present invention, the outdoor unit 2 further includes an outdoor throttling device 27, and two ends of the outdoor throttling device 27 are respectively connected to the second end of the outdoor heat exchanger 24 and the first end of the first refrigerant flow path a. Therefore, the reliability of the refrigerant flowing in the flow path of the multi-split system 100 can be ensured, and the multi-split system 100 can be operated reliably.

According to some embodiments of the present invention, the compressor 21 comprises a two-cylinder compressor 21. Therefore, the compressor 21 can be ensured to have two cylinders, the compression capacity of the compressor 21 on the refrigerant is improved, and meanwhile, the compressor 21 is known to have two suction ports, namely the first suction port 212 and the second suction port 213, so that the pressures of the refrigerant at the first suction port 212 and the second suction port 213 are different, the refrigerant has double evaporation temperatures when the indoor unit 1 of the multi-split air-conditioning system 100 performs refrigeration, and the energy efficiency of the multi-split air-conditioning system 100 is improved.

According to some embodiments of the present invention, compressor 21 includes a first compressor having a first discharge port and a first suction port 212 and a second compressor having a second discharge port and a second suction port 213, which together constitute discharge port 211. Therefore, it can be seen that the two compressors 21 may be independent from each other, and the high-temperature and high-pressure refrigerants discharged from the two compressors 21 may be collected together and then flow to the first port 221 and the first valve port 231. It is understood that when one of the compressors 21 has a problem, the other compressor 21 may be operated normally, thereby contributing to a reduction in the maintenance cost of the multi-split air-conditioning system 100. Meanwhile, the pressures of the refrigerants at the first suction port 212 and the second suction port 213 are different, so that the refrigerant has double evaporation temperatures when the indoor unit 1 of the multi-split air-conditioning system 100 performs refrigeration, and the energy efficiency of the multi-split air-conditioning system 100 is improved.

According to some embodiments of the present invention, the outdoor unit 2 includes a plurality of fans 28, and the plurality of fans 28 are independent of each other and are sequentially arranged in the flow direction of the airflow. Therefore, the multi-split air-conditioning system 100 can control the output efficiency of the outdoor heat exchanger 24 by controlling the rotation speed and the operation state of the plurality of fans 28, for example, when the difference between the indoor temperature and the set temperature is small when the multi-split air-conditioning system 100 is cooling, the fans 28 can be controlled to rotate and decrease, or part of the fans 28 can be turned off. When the difference between the indoor temperature and the set temperature is large, the plurality of fans 28 may be controlled to operate simultaneously and the rotation speed of the fans 28 may be increased. While some of the plurality of fans 28 may fail or stall, other fans 28 may still be operating properly. Thereby, the reliability of the multi-split system 100 may be improved, and the use of the multi-split system 100 may be more flexible.

Other configurations and operations of the multi-split system 100 according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A multiple on-line system, comprising:

each indoor unit comprises a main heat exchange assembly, and at least one indoor unit in the indoor units also comprises an auxiliary heat exchange assembly;

an outdoor unit including:

a compressor formed as a multi-cylinder compressor having a discharge port, a first suction port, and a second suction port;

a first reversing component comprising a first port to a fourth port, the first port in communication with the exhaust port and the first port in communication with one of a second port and a third port, the fourth port in communication with the other of the second port and the third port and the fourth port in communication with the first intake port;

a second direction changing assembly including first to fourth ports, the first port communicating with the exhaust port, the first port communicating with one of the second port and the third port, the fourth port communicating with the other of the second port and the third port, the fourth port communicating with the second suction port, the third port communicating with the fourth port, and a control valve connected between the third port and the fourth port;

the first end of the outdoor heat exchanger is connected with the third interface;

a first refrigerant flow path to a third refrigerant flow path, wherein a first end of the first refrigerant flow path is connected with a second end of the outdoor heat exchanger, a first end of the second refrigerant flow path is connected with the second interface, a first end of the third refrigerant flow path is connected with the second valve port, a second end of the first refrigerant flow path is respectively connected with a first end of the main heat exchange assembly and a first end of the auxiliary heat exchange assembly, a second end of the main heat exchange assembly is connected with a second end of the second refrigerant flow path, and a second end of the auxiliary heat exchange assembly is connected with a second end of the third refrigerant flow path;

when the multi-split air conditioner system is used for refrigerating, when the load in a room where an indoor unit comprising the main heat exchange assembly and the auxiliary heat exchange assembly in the multi-split air conditioner system is larger, the evaporation pressure of a refrigerant in the main heat exchange assembly is controlled to be larger than that of the refrigerant in the auxiliary heat exchange assembly, the main heat exchange assembly is positioned at the upstream of the auxiliary heat exchange assembly in the flowing direction of air entering the indoor unit,

the refrigerant flowing to the main heat exchange assembly flows to the first reversing assembly through a second refrigerant flow path and then flows back to the compressor through the first air suction port of the compressor; the refrigerant flowing to the auxiliary heat exchange assembly flows to the second reversing assembly through the third refrigerant flow path and then flows back to the compressor through the second suction port of the compressor;

the main heat exchange assembly comprises a main heat exchanger and a main throttling device which are arranged in series, the auxiliary heat exchange assembly comprises an auxiliary heat exchanger and an auxiliary throttling device which are arranged in series, the main throttling device is positioned between the main heat exchanger and the first refrigerant flow path, the auxiliary throttling device is positioned between the auxiliary heat exchanger and the first refrigerant flow path, and the main throttling device and the auxiliary throttling device are respectively formed into an electronic expansion valve.

2. A multi-split system as claimed in claim 1, wherein the control valve is a check valve for guiding the refrigerant from the fourth port to the third port.

3. A multi-split system as claimed in claim 1, wherein the control valve is an electronic expansion valve or a thermostatic expansion valve.

4. A multi-split system as claimed in claim 1, wherein at least one of the first and second reversing assemblies is a four-way valve.

5. A multi-split system as claimed in claim 1, wherein an on/off valve is provided on at least one of the first to third refrigerant paths.

6. A multi-split system as claimed in claim 5, wherein the switching valve is a solenoid valve or an electronic expansion valve.

7. A multi-split system as claimed in claim 1, wherein the outdoor unit further includes an outdoor throttling device, and both ends of the outdoor throttling device are connected to the second end of the outdoor heat exchanger and the first end of the first refrigerant flow path, respectively.

8. A multi-split system as claimed in claim 1, wherein the compressor comprises a twin-cylinder compressor.

9. A multi-split system as claimed in claim 1, wherein the compressors include a first compressor having a first discharge port and the first suction port and a second compressor having a second discharge port and the second suction port, the first and second discharge ports together constituting the discharge port.

10. A multi-split system as claimed in claim 1, wherein the outdoor unit includes a plurality of fans which are independent of each other and are arranged in sequence in a flow direction of the air current.

11. A multi-split system as claimed in claim 1, wherein the outdoor unit further comprises an oil separator, the oil separator includes an inlet, an outlet and an oil return port, the inlet is connected to the exhaust port, the outlet is connected to the first port and the first valve port, the oil return port is connected to the first suction port and/or the second suction port, and a capillary tube and/or a filter are disposed between the oil return port and the compressor.

12. A multi-split system as claimed in claim 1, wherein the outdoor unit further comprises a gas-liquid separator including a gas-liquid inlet and a gas outlet, the gas-liquid inlet being connected to the fourth port, and the gas outlet being connected to the first suction port.

13. A multi-split system as claimed in any one of claims 1 to 12, wherein the multi-split system is a tri-pipe multi-split system.