CN106382701A

CN106382701A - Multi-split air conditioner and outdoor unit thereof, and control method and device

Info

Publication number: CN106382701A
Application number: CN201611045943.1A
Authority: CN
Inventors: 于艳翠; 胡强; 沈军; 王永立; 杨健; 卢景斌; 游劭磊
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2016-11-22
Filing date: 2016-11-22
Publication date: 2017-02-08

Abstract

The invention discloses a multi-split air conditioner, an outdoor unit of the multi-split air conditioner, and a control method and device of the multi-split air conditioner. This multi-split air conditioner includes: interior machine system and outer machine system, wherein: the outdoor unit system comprises an outdoor unit system and a control device, wherein the outdoor unit system comprises a first outdoor heat exchanger and a second outdoor heat exchanger, and the first outdoor heat exchanger and the second outdoor heat exchanger are connected with the indoor unit system through refrigerant pipelines. The control device is electrically connected with the internal machine system and the external machine system respectively. The control device is used for controlling the working states of the first outdoor heat exchanger and the second outdoor heat exchanger according to the working mode of the indoor unit system, wherein the working states comprise a condenser, an evaporator and a refrigerant circulation-free state. The invention can switch the working state of the outdoor heat exchanger according to the working mode of the indoor unit system to ensure the load requirement of each indoor unit user, thereby improving the comfort of the user and the reliability of the unit.

Description

Multi-split air conditioner and outdoor unit thereof, and control method and device

Technical Field

The invention relates to the field of air conditioner control, in particular to a multi-split air conditioner and an outdoor unit, a control method and a control device thereof.

Background

The heat recovery multi-split system can meet the cold and hot load requirements of different users at the same time.

At present, a three-pipe heating recovery system mostly adopts an outdoor heat exchanger, and under the conditions of part of indoor units for refrigeration and part of indoor units for heating, the refrigerant distribution proportion and the heat exchange quantity of the outdoor heat exchanger directly influence the refrigeration capacity and the heating capacity of user indoor units.

In addition, under the condition of severe outdoor environment, such as minus 30 ℃, the common heat recovery unit cannot meet the heating capacity requirement of a user, the comfort of the user is reduced, and the energy efficiency of the air conditioning unit is very low.

Disclosure of Invention

In view of the above technical problems, the present invention provides a multi-split air conditioner, an outdoor unit thereof, a control method and a device thereof, which can switch the working state of an outdoor heat exchanger according to the working mode of an indoor unit system to ensure the load demand of each indoor unit user.

According to an aspect of the present invention, there is provided an outdoor unit of a multi-split air conditioner, including an outdoor unit system and a control device, wherein the outdoor unit system includes a first outdoor heat exchanger and a second outdoor heat exchanger, wherein:

the first outdoor heat exchanger and the second outdoor heat exchanger are connected with the indoor unit system through refrigerant pipelines;

the control device is respectively electrically connected with the internal machine system and the external machine system;

the control device is used for controlling the working states of the first outdoor heat exchanger and the second outdoor heat exchanger according to the working mode of the indoor unit system, wherein the working states comprise a condenser, an evaporator and a refrigerant circulation-free state.

In one embodiment of the present invention, the control device is further configured to control the first outdoor heat exchanger and the second outdoor heat exchanger to serve as evaporators when the indoor unit system is in the full heating mode;

or,

when the indoor unit system is in a main heating mode or a small-load heating mode, controlling the first outdoor heat exchanger to serve as an evaporator and the second outdoor heat exchanger to serve as a condenser;

or,

controlling the first outdoor heat exchanger and the second outdoor heat exchanger to serve as condensers when the indoor unit system is in a complete refrigeration mode;

or,

when the internal machine system is in a main body refrigeration mode, controlling the first outdoor heat exchanger to serve as a condenser and the second outdoor heat exchanger to serve as an evaporator;

or,

when the indoor unit system is in a small-load refrigeration mode, the first outdoor heat exchanger is controlled to serve as a condenser, and the second outdoor heat exchanger does not participate in refrigerant circulation;

or,

and controlling the first outdoor heat exchanger and the second outdoor heat exchanger not to participate in refrigerant circulation when the indoor unit system is in a heat recovery mode.

In an embodiment of the present invention, the outdoor unit system further includes a refrigerant pipeline control valve, wherein:

the refrigerant pipeline control valve is arranged in a refrigerant pipeline and comprises at least one of a four-way valve, an electronic expansion valve and an electromagnetic valve;

the control device is used for controlling the working state of the first outdoor heat exchanger and the working state of the second outdoor heat exchanger by controlling the opening and closing of the refrigerant pipeline control valve.

In one embodiment of the present invention, the refrigerant line control valve includes an electronic expansion valve of the first outdoor heat exchanger and an electronic expansion valve of the second outdoor heat exchanger, wherein:

the electronic expansion valve of the first outdoor heat exchanger is connected with the first outdoor heat exchanger, and the electronic expansion valve of the second outdoor heat exchanger is connected with the second outdoor heat exchanger;

the control device is used for controlling the opening degrees of the electronic expansion valve of the first outdoor heat exchanger and the electronic expansion valve of the second outdoor heat exchanger to be 0 when the indoor unit system is in a heat recovery mode so as to control the first outdoor heat exchanger and the second outdoor heat exchanger not to participate in refrigerant circulation, so that low-pressure refrigerant flowing out of the refrigerating indoor unit is returned to the heating indoor unit after being processed by a compressor of the outdoor unit system;

the control device is used for controlling the opening degree of the electronic expansion valve of the second outdoor heat exchanger to be 0 when the indoor unit system is in a small-load heating mode so as to control the second outdoor heat exchanger not to participate in refrigerant circulation.

In one embodiment of the present invention, the outdoor unit system further includes a compressor, a gas make-up solenoid valve, and a subcooler, wherein:

the subcooler is connected with the air supplement port of the compressor through an air supplement electromagnetic valve; the control device is electrically connected with the air replenishing electromagnetic valve;

the control device is also used for controlling the air supply electromagnetic valve to be opened under the condition that the compressor needs air supply so as to control air path refrigerants of the subcooler to enter the compressor for air supply.

In one embodiment of the present invention, the outdoor unit system further includes an air make-up electronic expansion valve, wherein:

the gas-supplementing electronic expansion valve is arranged on an auxiliary path of the subcooler, and the control device is electrically connected with the gas-supplementing electronic expansion valve;

the control device is also used for controlling the air supplement amount of the compressor by controlling the opening of the air supplement electronic expansion valve under the condition that the compressor needs air supplement.

In one embodiment of the present invention, the outdoor unit system further includes a supercooling regulating solenoid valve, wherein:

the subcooler is connected with the inlet of the low-pressure side gas-liquid separator through a subcooling regulating electromagnetic valve; the control device is electrically connected with the supercooling regulating electromagnetic valve;

the control device is also used for controlling the supercooling regulating electromagnetic valve to be closed and the gas supplementing electromagnetic valve to be opened under the condition that the compressor needs to supplement gas, and controlling the gas path refrigerant of the subcooler to enter the compressor for supplementing gas; and under the condition that the compressor does not need air supplement, controlling the supercooling regulating electromagnetic valve to be opened, closing the air supplement electromagnetic valve, controlling air path refrigerant of the subcooler to enter an inlet of the low-pressure side gas-liquid separator, and regulating the supercooling degree of the unit.

In one embodiment of the present invention, the outdoor unit system further includes an electronic expansion valve of the first outdoor heat exchanger and an electronic expansion valve of the second outdoor heat exchanger, wherein:

the subcooler is connected with the first outdoor heat exchanger through an electronic expansion valve of the first outdoor heat exchanger; the subcooler is connected with the second outdoor heat exchanger through an electronic expansion valve of the second outdoor heat exchanger;

the control device is also used for controlling the supercooling degree by controlling the opening degree of the air supply electronic expansion valve under the condition that the supercooling degree of the system needs to be adjusted; or, under the condition that the system needs to adjust the supercooling degree, the control of the supercooling degree is realized by controlling the opening degrees of the electronic expansion valve of the first outdoor heat exchanger and the electronic expansion valve of the second outdoor heat exchanger.

In one embodiment of the present invention, the outer machine system further includes a first variable capacity solenoid valve and a second variable capacity solenoid valve, and the compressor includes a first variable capacity compressor and a second variable capacity compressor, wherein:

the first variable capacity compressor and the second variable capacity compressor are connected in parallel;

one end of the first variable capacitance electromagnetic valve is connected with the air suction pipelines of the first variable capacitance compressor and the second variable capacitance compressor, and the other end of the first variable capacitance electromagnetic valve is connected with the variable capacitance ports of the first variable capacitance compressor and the second variable capacitance compressor;

one end of the second variable capacitance electromagnetic valve is connected with the exhaust pipelines of the first variable capacitance compressor and the second variable capacitance compressor, and the other end of the second variable capacitance electromagnetic valve is connected with the variable capacitance ports of the first variable capacitance compressor and the second variable capacitance compressor;

the control device is also used for controlling the first variable capacitance electromagnetic valve to be closed and the second variable capacitance electromagnetic valve to be opened under the condition that the system needs to operate in three cylinders; and under the condition that the system needs double-cylinder operation, the first variable-capacity electromagnetic valve is controlled to be opened, and the second variable-capacity electromagnetic valve is controlled to be closed.

In one embodiment of the present invention, the external machine system further includes an oil separator and an oil-equalizing solenoid valve, wherein:

the air inlet pipe of the oil separator is connected with an air outlet pipeline of the compressor, and is also connected with an oil equalizing pipe at the bottom of the compressor through an oil equalizing electromagnetic valve;

the control device is also used for controlling the oil-balancing electromagnetic valve to be opened under the condition that the oil level of the compressor exceeds the position of the oil-balancing hole at the bottom of the compressor.

In one embodiment of the present invention, the external unit system further includes a first oil return solenoid valve, a second oil return solenoid valve, and a third oil return solenoid valve, wherein:

the first oil return electromagnetic valve is arranged in a pipeline between an oil return pipe at the bottom of the oil separator and a compressor air suction port; the second oil return electromagnetic valve is arranged in a pipeline between an oil outlet pipe at the bottom of the gas-liquid separator and an air suction port of the compressor; the third oil return electromagnetic valve is arranged in a pipeline between the air outlet of the compressor and the air outlet of the oil separator;

the control device is also used for controlling the first oil return electromagnetic valves to be opened under the condition that the system runs; and under the condition that the compressor is lack of oil, controlling the second oil return electromagnetic valve and the third oil return electromagnetic valve to be opened.

According to another aspect of the present invention, there is provided a multi-split air conditioner including an indoor unit system, and an outdoor unit as described in any one of the above embodiments.

In one embodiment of the present invention, the multi-split air conditioner further includes a mode converter, wherein:

the mode converter is respectively connected with the internal machine system and the external machine system through refrigerant pipelines;

and the mode converter is used for distributing corresponding refrigerants to each internal machine according to the mode requirements of each internal machine and conveying the refrigerants returned by the internal machine system to the external machine system.

According to another aspect of the present invention, there is provided a multi-split air conditioner control method including:

acquiring a working mode of an internal machine system;

and controlling the first outdoor heat exchanger and the second outdoor heat exchanger to be in corresponding working states according to the working mode of the indoor unit system, wherein the first outdoor heat exchanger and the second outdoor heat exchanger are connected with the indoor unit system through refrigerant pipelines, and the working states comprise a condenser, a condenser and no participation in refrigerant circulation.

In an embodiment of the present invention, the controlling the first outdoor heat exchanger and the second outdoor heat exchanger to be in the corresponding operating states according to the operating mode of the indoor unit system includes:

controlling the first outdoor heat exchanger and the second outdoor heat exchanger to serve as evaporators when the indoor unit system is in a complete heating mode;

In one embodiment of the present invention, the controlling the first outdoor heat exchanger and the second outdoor heat exchanger in the respective operation states includes:

the control of the working state of the first outdoor heat exchanger and the working state of the second outdoor heat exchanger is realized by controlling the opening and closing of a refrigerant pipeline control valve, wherein the refrigerant pipeline control valve is arranged in a refrigerant pipeline, and the refrigerant pipeline control valve comprises at least one of a four-way valve, an electronic expansion valve and an electromagnetic valve.

In one embodiment of the invention, the method further comprises:

and under the condition that the compressor needs air supplement, the air supplement electromagnetic valve is controlled to be opened so as to control air path refrigerants of the subcooler to enter the compressor for air supplement, wherein the subcooler is connected with an air supplement port of the compressor through the air supplement electromagnetic valve.

In one embodiment of the invention, the method further comprises:

under the condition that the compressor needs air supplement, the air supplement amount of the compressor is controlled by controlling the opening of the air supplement electronic expansion valve, wherein the air supplement electronic expansion valve is arranged on an auxiliary path of the subcooler.

In one embodiment of the invention, the method further comprises:

under the condition that the compressor needs air supplement, the supercooling regulating electromagnetic valve is controlled to be closed, the air supplement electromagnetic valve is controlled to be opened, and air path refrigerants of the subcooler are controlled to enter the compressor for air supplement, wherein the subcooler is connected with an inlet of the low-pressure side gas-liquid separator through the supercooling regulating electromagnetic valve;

under the condition that the compressor does not need air supplement, the supercooling regulating electromagnetic valve is controlled to be opened, the air supplement electromagnetic valve is controlled to be closed, air path refrigerants of the subcooler are controlled to enter an inlet of the low-pressure side gas-liquid separator, and the supercooling degree of the unit is regulated.

In one embodiment of the invention, the method further comprises:

under the condition that the supercooling degree of the system needs to be adjusted, the opening degree of the air supply electronic expansion valve is controlled to realize the control of the supercooling degree;

or,

under the condition that the supercooling degree of the system needs to be adjusted, the control of the supercooling degree is realized by controlling the opening degrees of the electronic expansion valve of the first outdoor heat exchanger and the electronic expansion valve of the second outdoor heat exchanger, wherein the subcooler is connected with the first outdoor heat exchanger through the electronic expansion valve of the first outdoor heat exchanger, and the subcooler is connected with the second outdoor heat exchanger through the electronic expansion valve of the second outdoor heat exchanger.

In one embodiment of the invention, the method further comprises:

under the condition that the system needs three-cylinder operation, controlling a first variable capacitance electromagnetic valve to be closed and a second variable capacitance electromagnetic valve to be opened, and switching a compressor to a three-cylinder operation state, wherein the compressor comprises a first variable capacitance compressor and a second variable capacitance compressor which are connected in parallel;

and under the condition that the system needs double-cylinder operation, the first variable-capacity electromagnetic valve is controlled to be opened, and the second variable-capacity electromagnetic valve is controlled to be closed.

In one embodiment of the invention, the method further comprises:

and under the condition that the oil level of the compressor exceeds the position of an oil equalizing hole at the bottom of the compressor, controlling the oil equalizing electromagnetic valve to be opened, wherein the air inlet pipe of the oil separator is connected with the air outlet pipeline of the compressor, and the air inlet pipe of the oil separator is also connected with an oil equalizing pipe at the bottom of the compressor through the oil equalizing electromagnetic valve.

In one embodiment of the invention, the method further comprises:

under the condition of system operation, controlling a first oil return electromagnetic valve to be opened, wherein the first oil return electromagnetic valve is arranged in a pipeline between an oil return pipe at the bottom of the oil separator and a suction port of the compressor;

and under the condition that the compressor is lack of oil, controlling a second oil return electromagnetic valve and a third oil return electromagnetic valve to be opened, wherein the second oil return electromagnetic valve is arranged in a pipeline between an oil outlet pipe at the bottom of the gas-liquid separator and an air suction port of the compressor, and the third oil return electromagnetic valve is arranged in a pipeline between an air outlet of the compressor and an air outlet of the oil separator.

According to another aspect of the present invention, there is provided a multi-split air conditioner control apparatus including a memory and a processor, wherein:

a memory to store instructions;

and a processor for executing the instructions to cause the apparatus to perform operations for implementing the multi-split air conditioner control method according to any one of the above embodiments.

The invention can switch the working state of the outdoor heat exchanger according to the working mode of the indoor unit system to ensure the load requirement of each indoor unit user, thereby improving the comfort of the user and the reliability of the unit.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic view illustrating a first embodiment of a multi-split air conditioner according to the present invention.

Fig. 2 is a schematic view of a multi-split air conditioner according to a second embodiment of the present invention.

Fig. 3 is a schematic view of a multi-split air conditioner according to a third embodiment of the present invention.

Fig. 4 is a schematic diagram of an external unit system of the multi-split air conditioner in the embodiment of fig. 3.

FIG. 5 is a schematic port diagram of the four-way valve of the embodiment of FIGS. 3 and 4.

Fig. 6 is a schematic diagram illustrating a control method of a multi-split air conditioner according to a first embodiment of the invention.

Fig. 7 is a schematic diagram illustrating a control method of a multi-split air conditioner according to a second embodiment of the invention.

Fig. 8 is a schematic diagram illustrating a control method of a multi-split air conditioner according to a third embodiment of the invention.

Fig. 9 is a schematic diagram illustrating a control method for a multi-split air conditioner according to a fourth embodiment of the invention.

Fig. 10 is a schematic diagram illustrating a control method for a multiple on-line air conditioner according to a fifth embodiment of the invention.

Fig. 11 is a schematic diagram of an embodiment of the multi-split air conditioner control device according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Fig. 1 is a schematic view illustrating a first embodiment of a multi-split air conditioner according to the present invention. As shown in fig. 1, the multiple on-line air conditioner includes an indoor unit system 15 and an outdoor unit, wherein:

the outdoor unit includes an outdoor unit system 17 and a control device 18, wherein the outdoor unit system 17 may include a first outdoor heat exchanger 1a and a second outdoor heat exchanger 1b, wherein:

the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b are connected to an indoor unit system 15 through refrigerant pipes.

The control device 18 is electrically connected to the indoor unit system 15 and the outdoor unit system 17, respectively.

The control device 18 is configured to control the operating states of the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b according to the operating mode of the indoor unit system 15, wherein the operating states include the function as a condenser, the function as an evaporator, and the non-participation in the refrigerant circulation.

In one embodiment of the present invention, the operation mode of the internal machine system 15, i.e. the heat recovery system operation mode, may include: a full heating mode, a main body heating mode, a small load heating mode, a full cooling mode, a main body cooling mode, a small load cooling mode, and a heat recovery mode.

The full cooling mode refers to that all the turned-on internal machines are in the cooling mode.

The small load cooling mode means that all the internal machines which are started up are in the cooling mode, but the capacity of the internal machines which are started up is smaller and is about 1/4 of the capacity of the external machines.

The main cooling mode refers to that some of the internal machines which are started are cooling modes, and the other internal machines are heating modes, wherein the cooling capacity of the cooling internal machines is larger than the heating capacity of the heating internal machines.

The main heating mode refers to that some of the internal machines which are started are in a cooling mode, and the other internal machines are in a heating mode, wherein the heating quantity of the internal machines is larger than the cooling quantity of the cooling internal machines.

The heat recovery mode refers to that some of the internal machines which are started are in a cooling mode, and the other internal machines are in a heating mode, wherein the heating quantity of the internal machines for heating is equal to the cooling quantity of the cooling internal machines.

The complete heating mode means that all the turned-on internal machines are in the heating mode.

The small-load heating mode means that all the internal machines are in the heating mode when the machine is started, but the capacity of the internal machines is smaller and is about 1/4 of the capacity of the external machines.

In an embodiment of the present invention, the control device 18 may be specifically configured to control the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b to function as evaporators when the indoor unit system 15 is in the full heating mode.

Or,

in the case where the indoor unit system 15 is in the main heating mode or the small-load heating mode, the first outdoor heat exchanger 1a is controlled to function as an evaporator, and the second outdoor heat exchanger 1b functions as a condenser.

Or,

in the full cooling mode of the indoor unit system 15, the first and second outdoor heat exchangers 1a and 1b are controlled to function as condensers.

Or,

in the main cooling mode of the internal machine system 15, the first outdoor heat exchanger 1a is controlled to function as a condenser, and the second outdoor heat exchanger 1b functions as an evaporator.

Or,

and under the condition that the internal machine system 15 is in a small-load refrigeration mode, the first outdoor heat exchanger 1a is controlled to serve as a condenser, and the second outdoor heat exchanger 1b does not participate in refrigerant circulation.

Or,

and controlling the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b not to participate in refrigerant circulation when the indoor unit system 15 is in the heat recovery mode.

Based on the heat recovery multi-split air conditioner or the outdoor unit of the heat recovery multi-split air conditioner provided by the embodiment of the invention, the working state of the outdoor heat exchanger can be switched according to the working mode of the indoor unit system (for example, under the conditions of partial indoor unit refrigeration, partial indoor unit heating and extreme working condition) so as to ensure the load requirements of each indoor unit user, thereby improving the comfort of the user and the reliability of the unit; the embodiment of the invention can meet the requirement that the heating capacity is not attenuated at the low temperature of-20 ℃; the embodiment of the invention can meet the requirements of heating and small load of the main refrigeration body under the limit working condition, and ensure that the comfort of users is not attenuated.

Fig. 2 is a schematic view of a multi-split air conditioner according to a second embodiment of the present invention. Compared to the embodiment shown in fig. 1, in the embodiment shown in fig. 2, the multi-split air conditioner may further include a mode converter 16, wherein:

the mode converter 16 is connected to the indoor unit system 15 and the outdoor unit system 17 through refrigerant lines, respectively.

And the mode converter 16 is configured to distribute corresponding refrigerant to each internal machine according to the mode requirement of each internal machine, and convey the refrigerant returned by the internal machine system 15 to the external machine system 17.

The invention can switch the working state of the outdoor heat exchanger according to the working mode of the indoor unit system 15 to ensure the load requirement of each indoor unit user, thereby improving the comfort of the user and the reliability of the unit.

Fig. 3 is a schematic view of a multi-split air conditioner according to a third embodiment of the present invention. Fig. 4 is a schematic diagram of an external unit system of the multi-split air conditioner in the embodiment of fig. 3. As shown in fig. 3 and 4, the outer machine connecting pipe is a three-pipe, a liquid pipe L1, a low pressure gas pipe G2, and a high pressure gas pipe G1.

As shown in fig. 3, the mode converter 16 has three pipes connected to the external side and two pipes connected to the respective internal sides. The mode converter 16 performs a refrigerant distribution function, and delivers corresponding refrigerants to each of the indoor units according to the mode requirements of each of the indoor units, and returns the refrigerants to the outdoor unit.

For example: the indoor unit N1 refrigerates, the mode converter 16 distributes high-pressure liquid refrigerant to the indoor unit, the high-pressure liquid refrigerant is throttled by the indoor unit electronic expansion valve 14a, evaporated and heat exchanged by the indoor unit heat exchanger 15a, and then returns to low-pressure gaseous refrigerant to a low-pressure air pipe on the outer machine side of the mode converter 16; meanwhile, the indoor unit N2 heats, the mode converter 16 distributes high-pressure gaseous refrigerant to the indoor unit, the high-pressure gaseous refrigerant is condensed by the indoor unit heat exchanger 15b to release heat, is primarily throttled by the electronic expansion valve 14b to be liquid refrigerant with higher pressure, and returns to the liquid pipe on the outer side of the mode converter. That is, the mode converter 16 delivers the high-pressure liquid refrigerant to the refrigeration indoor unit and delivers the high-pressure gaseous refrigerant to the heating indoor unit.

In an embodiment of the present invention, the outdoor unit system 17 may further include a refrigerant pipeline control valve, wherein:

the refrigerant pipeline control valve is arranged in a refrigerant pipeline and comprises at least one of control valves such as a four-way valve, an electronic expansion valve and a solenoid valve.

The control device 18 is used for controlling the working state of the first outdoor heat exchanger 1a and the working state of the second outdoor heat exchanger 1b by controlling the opening and closing of the refrigerant pipeline control valve, so that the working state of the first outdoor heat exchanger and the working state of the second outdoor heat exchanger can be conveniently, accurately and quickly controlled.

The refrigerant circulation system in the outdoor unit system will be further described with reference to fig. 3 and 4, that is, how to control and switch the working states of the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b in the outdoor unit system by controlling the on/off of the refrigerant pipeline control valve in 7 different indoor unit working modes is specifically described.

In the embodiments of fig. 3 and 4, 1a and 1b are external machine heat exchangers; 2a and 2b are external fans; 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h and 3i are filters; 4a, 4b and 4c are electronic expansion valves of an outdoor unit; 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l, 5m, 5n, 5o are solenoid valves; 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h, 6i, 6j are check valves; 7 is a gas-liquid separator; 8a and 8b are compressors; 9 is an oil separator; the 10a and the 10b are four-way valves; 11a, 11b, 11c and 11d are stop valves; 12a, 12b, 12c, 12d, 12e are capillaries; 13 is a subcooler; 14a, 14b and 14c are internal electronic expansion valves; 15a, 15b and 15c are internal machine heat exchangers; 16 is a mode converter; t1, T2, T3, T4, T5, T6, T7, T8, T9 and T10 are temperature sensors; p1, P2 and P3 are pressure sensors; p4 and P5 are high-voltage switches; g1 is a high-pressure air pipe; g2 is a low-pressure air pipe; l1 is a liquid pipe; n1, N2 and N3 are internal machines.

The four-way valve shown in fig. 5 is a schematic port diagram of the four-way valves 10a and 10b in the embodiments of fig. 3 and 4.

As shown in fig. 3 and 4, a port a of the four-way valve 10a is connected to the second outdoor heat exchanger 1B through a solenoid valve 5C, a port B of the four-way valve 10a is connected to a low-pressure gas pipe G2 through a filter 3e and a capillary tube 12a, a port C of the four-way valve 10a is connected to a low-pressure gas pipe G2, and a port D of the four-way valve 10a is connected to the first outdoor heat exchanger 1 a.

As shown in fig. 3 and 4, a port a of the four-way valve 10B is connected to the air outlet of the oil separator 9 via check valves 6i and 6j, a port B of the four-way valve 10B is connected to a high-pressure air pipe G1, a port C of the four-way valve 10B is connected to a low-pressure air pipe G2, and a port D of the four-way valve 10B is connected to a low-pressure air pipe G2 via a filter 3f and a capillary tube 12B.

When the four-way valve is opened (namely, the four-way valve is reversed), the ports AB are communicated and the ports CD are communicated; and when the four-way valve is closed, the port AD is communicated and the port BC is communicated.

First, in the complete cooling mode, the control device controls the four-way valve 10a to be turned off and the four-way valve 10b to be turned off. Refrigerant in a low-pressure gas pipe G2 flows to the suction side (suction port) of the compressors 8a and 8b through the gas-liquid separator 7, the compressors 8a and 8b are arranged in parallel, high-temperature exhaust gas from the exhaust pipe of the compressor is converged through the check valves 6G and 6h respectively and enters the oil separator 9, a part of separated high-pressure gaseous refrigerant enters the first outdoor heat exchanger 1a through the four-way valve 10a and is condensed into liquid refrigerant, the other part of high-pressure gaseous refrigerant enters the second outdoor heat exchanger 1b through the electromagnetic valve 5c and is condensed into liquid refrigerant, and the two parts of liquid refrigerant are converged together through the filter 3a/3b, the electromagnetic valve 5a/5b and the check valve 6a/6b respectively and enter the subcooler 13. The sub-path refrigerant enters the subcooler 13 for cooling the main path refrigerant after being throttled by the electronic expansion valve 4c, the main path refrigerant enters the subcooler 13 for being subcooled, and enters the outdoor unit side liquid pipe of the mode converter 16 after passing through the filter 3i and the liquid valve 11 c. The four-way valve 10b is closed, i.e. the high-pressure gas pipe G1 is communicated with the low-pressure gas pipe G2. The solenoid valve 5c is opened and the solenoid valve 5d is closed. I.e., the first and second outdoor heat exchangers 1a and 1b function as condensers.

Second, in the small load cooling mode, the difference from the full cooling mode is that: the control device controls the electromagnetic valve 5c to be closed, the electromagnetic valve 5d to be opened, and the opening degree of the electronic expansion valve 4b to be 0. That is, the second exterior heat exchanger 1b does not have the refrigerant flowing therethrough, and the first exterior heat exchanger 1a functions as a condenser.

Third, in the main body cooling mode, the control device controls the four-way valve 10a to be turned off and the four-way valve 10b to be turned on. Part of the high-pressure gaseous refrigerant from the oil separator enters the first outdoor heat exchanger 1a through the four-way valve 10a to be condensed into liquid refrigerant, the liquid refrigerant enters the subcooler 13 after passing through the filter 3a, the electromagnetic valve 5a and the one-way valve 6a, the auxiliary path refrigerant enters the subcooler 13 after being throttled by the electronic expansion valve 4c to cool the main path refrigerant, the main path refrigerant enters the subcooler 13 to be subcooled, and the main path refrigerant enters the outer machine side liquid pipe of the 16-mode converter after passing through the filter 3i and the liquid valve 11 c. The other part of the separated high-pressure gaseous refrigerant is communicated with a high-pressure gas pipe connecting pipe G1 through a check valve 6j and a four-way valve 10 b. The solenoid valve 5c is closed, the solenoid valve 5d is opened, and the electronic expansion valve 4b has an opening degree, i.e., the first outdoor heat exchanger 1a functions as a condenser and the second outdoor heat exchanger 1b functions as an evaporator.

Fourth, in the complete heating mode, the control device controls the four-way valve 10a to be turned on and the four-way valve 10b to be turned on. That is, the liquid refrigerant flowing from the liquid pipe on the indoor unit mode converter side enters the subcooler 13 through the filter 3i to be subcooled, and the sub-path liquid refrigerant is throttled by the electronic expansion valve 4c and then enters the subcooler 13 to be used for cooling the main path refrigerant. The sub-cooled main refrigerant is respectively throttled by an electronic expansion valve 4a/4b, and communicated with a low-pressure side air pipe through a filter 3a/3b, a heat exchanger 1a/1b and a four-way valve 10 a. The solenoid valve 5c is closed and the solenoid valve 5d is opened, i.e. the first outdoor heat exchanger 1a, 1b acts as an evaporator.

Fifth, the small load heating mode is different from the full heating mode in that: the control device controls the electromagnetic valve 5c to be opened, the electromagnetic valve 5d to be closed and the electronic expansion valve 4b to have an opening degree. At this time, the second outdoor heat exchanger 1b functions as a condenser, and the first outdoor heat exchanger 1a functions as an evaporator.

Sixth, in the main body heating mode, the difference from the heating mode is: the control device controls the opening degree of the electronic expansion valve 4b to 0. The operation of the refrigerant pipeline control valve is consistent with that of the refrigerant pipeline control valve in the small-load heating mode.

Seventh, in the heat recovery mode, the control device controls the four-way valve 10a to be opened, the four-way valve 10b to be opened, the opening degrees of the electronic expansion valves 4a, 4b, and 4c to be 0, the solenoid valve 5c to be closed, and the solenoid valve 5d to be opened. That is, a low-pressure gas pipe (low-pressure refrigerant flowing out of the refrigerating internal machine) on the mode converter side flows to the suction sides of the compressors 8a and 8b through the gas-liquid separator 7, the compressors 8a and 8b are arranged in parallel, high-temperature exhaust gas from the exhaust pipe of the compressor is converged after passing through the check valves 6G and 6h, enters the oil separator 9, and most of the separated high-pressure gaseous refrigerant enters the high-pressure gas pipe G1 through the check valve 6j and the four-way valve 10b and is distributed to the heating internal machine through the mode converter. A small part of high-pressure gaseous refrigerant enters the branched filter 3e and the capillary tube 12c through the four-way valve 10a to be decompressed and communicated with the low-pressure air pipe. The liquid pipe refrigerant of the outdoor unit is a high-pressure liquid refrigerant flowing out of the heating indoor unit, and the refrigerant does not enter the heat exchangers 1a and 1b of the outdoor unit and is distributed to the refrigerating indoor unit through the mode converter. That is, the outdoor unit heat exchangers 1a and 1b do not participate in the refrigerant circulation.

The low-temperature heat recovery multi-connected outdoor unit outdoor heat exchanger in the embodiment of the invention consists of two heat exchangers with different heat exchange areas, and the electronic expansion valve of each heat exchanger liquid pipe is connected with a one-way valve and an electromagnetic valve in parallel; only the first outdoor heat exchanger 1a is opened under the working conditions of heating of the ultra-low temperature main body and refrigerating of the ultra-low temperature main body; and when the maximum heating is low in load, the first outdoor heat exchanger 1a is an evaporator, and the second outdoor heat exchanger 1b is a condenser.

According to the embodiment of the invention, under the conditions of extreme working conditions and partial loads, the energy efficiency can be improved by 20%; the heating capacity of the embodiment of the invention is not attenuated at the temperature of-20 ℃, the heating capacity of the embodiment of the invention can reach more than 70 percent of the nominal heating capacity at the temperature of-30 ℃, and the high-temperature refrigerating capacity reaches more than 90 percent of the nominal refrigerating capacity; the height drop of the unit can be increased to 150m (the external unit is on the upper side) according to the embodiment of the invention.

The compressors 8a and 8b of the above embodiments of the present invention may be scroll compressors or rotor compressors. 2 or more compressors can be adopted.

Because the cost of the rotor compressor is lower than that of a scroll compressor, the cost of the whole compressor is reduced to a certain extent after the rotor compressor is adopted, and the product competitiveness is increased.

In the above embodiment of the present invention, the size ratio of the heat exchange areas of the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b is controlled.

In an embodiment of the present invention, as shown in fig. 3 and 4, the outdoor unit system 17 may further include an air-make-up enthalpy increasing system, wherein the air-make-up enthalpy increasing system may include an air-make-up solenoid valve 5f and a subcooler 13, wherein:

the subcooler 13 is connected with the air supplement port of the compressor through an air supplement electromagnetic valve 5 f; the control device 18 is electrically connected with the air replenishing electromagnetic valve 5 f.

The control device 18 can also be used for controlling the gas supplementing electromagnetic valve 5f to be opened under the condition that the compressor needs gas supplementing so as to control the gas path refrigerant of the subcooler 13 to enter the compressor for gas supplementing.

In an embodiment of the present invention, as shown in fig. 3 and 4, the outdoor unit system 17 may further include an air make-up electronic expansion valve 4c, wherein:

the air supply electronic expansion valve 4c is arranged on the auxiliary path of the subcooler 13, and the control device 18 is electrically connected with the air supply electronic expansion valve 4 c.

The control device 18 can also be used for controlling the air supplement amount of the compressor by controlling the opening degree of the air supplement electronic expansion valve 4c under the condition that the compressor needs air supplement, so that the air supplement amount can be conveniently and accurately controlled.

In one embodiment of the present invention, as shown in fig. 3 and 4, the vapor-supplementing enthalpy-increasing system may further include check valves 6c, 6d and compressors 8a, 8 b. As shown in fig. 3 and 4, the gas-filling enthalpy-increasing system adopts a gas-filling enthalpy-increasing mode to improve the system capacity and the energy efficiency ratio according to the change of the system load, the ambient temperature and the exhaust superheat degree. The control device 18 controls the gas supplementing electromagnetic valve 5f to be opened, the auxiliary path refrigerant of the subcooler 13 is throttled by the gas supplementing electronic expansion valve 4c, exchanges heat with the main path refrigerant to become superheated gas, and enters the compressors 8a and 8b for supplementing gas through the gas supplementing electromagnetic valve 5f and the one-way valves 6c/6 d.

In an embodiment of the present invention, as shown in fig. 3 and 4, the outboard engine system 17 may further include temperature sensors T1-T10 and pressure sensors P1-P3, wherein the control device 18 determines the exhaust superheat degree according to the measured values of the temperature sensors T1-T10 and the pressure sensors P1-P3, for example, the exhaust superheat degree may be determined according to the difference between the exhaust temperature and the exhaust pressure and the saturation temperature.

In one embodiment of the present invention, as shown in fig. 3 and 4, the outdoor unit system 17 may further include a supercooling degree adjusting system, wherein the supercooling degree adjusting system may include a supercooling degree adjusting solenoid valve 5e, wherein:

the subcooler 13 is connected with the inlet of the low-pressure side gas-liquid separator through a subcooling adjusting electromagnetic valve 5 e; the control device 18 is electrically connected to the supercooling regulating solenoid valve 5 e.

The control device 18 can also be used for controlling the supercooling regulating electromagnetic valve 5e to be closed and the gas supplementing electromagnetic valve 5f to be opened under the condition that the compressor needs to supplement gas, and controlling the gas path refrigerant of the subcooler 13 to enter the compressor for supplementing gas; and under the condition that the compressor does not need air supplement, controlling the supercooling regulating electromagnetic valve 5e to be opened, closing the air supplement electromagnetic valve 5f, controlling the air path refrigerant of the subcooler 13 to enter the inlet of the low-pressure side gas-liquid separator, and regulating the supercooling degree of the unit.

In one embodiment of the present invention, the outdoor unit system 17 may further include an electronic expansion valve 4a of the first outdoor heat exchanger 1a and an electronic expansion valve 4b of the second outdoor heat exchanger 1b, wherein:

the subcooler 13 is connected with the first outdoor heat exchanger 1a through the electronic expansion valve 4a of the first outdoor heat exchanger 1 a; the subcooler 13 is connected to the second outdoor heat exchanger 1b through the electronic expansion valve 4b of the second outdoor heat exchanger 1 b.

The control device 18 can also be used for controlling the supercooling degree by controlling the opening degree of the air supply electronic expansion valve 4c under the condition that the supercooling degree of the system needs to be adjusted; or, when the system needs to adjust the supercooling degree, the opening degree of the electronic expansion valve 4a of the first outdoor heat exchanger 1a and the opening degree of the electronic expansion valve 4b of the second outdoor heat exchanger 1b are controlled to control the supercooling degree.

The supercooling degree adjusting system of the above embodiment of the present invention has the following implementation modes: when the system detects that the supercooling degree of the unit is small, measures can be taken to increase the supercooling degree, so that the comfort requirement of a user is ensured.

The common mode is as follows: the sub-channel refrigerant of the subcooler 13 is throttled by the air supply electronic expansion valve 4c to exchange heat with the main channel refrigerant and become superheated gas. When the compressor does not need air supplement, the electromagnetic valve 5e is opened, the electromagnetic valve 5f is closed, and the superheated gas enters the inlet of the low-pressure side gas-liquid separator 7. When the compressor needs air supplement, the electromagnetic valve 5e is closed, the electromagnetic valve 5f is opened, and the superheated gas enters the air supplement inlets of the compressors 8a and 8 b. The opening degree of the electronic expansion valve 4c adjusts the degree of supercooling.

If the internal machine system is in a cooling or heating mode, another adjusting mode exists, namely the flow of the liquid refrigerants of the external machine heat exchangers 1a and 1b is controlled, namely the electromagnetic valves 5a and 5b are closed, and the supercooling degree is controlled by the opening degrees of the electronic expansion valves 4a and 4 b. Similarly, if the internal machine system is in the main body cooling or main body heating mode, the supercooling degree is controlled by only controlling the opening degree of the electronic expansion valve 4 a.

The invention can adjust the supercooling degree of the unit through the opening degree of the electronic expansion valve 4c of the subcooler or the electronic expansion valves 4a and 4b of the liquid pipe of the outdoor unit heat exchanger, thereby accurately and conveniently realizing the adjustment of the supercooling degree of the unit.

The embodiment of the invention can inquire the corresponding high-pressure saturation temperature through the high-pressure sensor. Specifically, in the refrigeration mode, the supercooling degree of the unit can be determined according to the difference value between the outlet temperature of the condenser and the high-pressure saturation temperature; in the heating mode, the supercooling degree of the unit can be determined according to the difference between the temperature of the inner liquid pipe (the temperature sensing bulb arranged on the inner liquid pipe) and the high-pressure saturation temperature.

In one embodiment of the present invention, as shown in fig. 3 and 4, the outer machine system 17 may further include a compressor variable capacity system, wherein the compressor variable capacity system may include a first variable capacity solenoid valve 5j and a second variable capacity solenoid valve 5k, and the compressor may include a first variable capacity compressor 8a and a second variable capacity compressor 8b, wherein:

the first variable capacity compressor 8a and the second variable capacity compressor 8b are connected in parallel.

One end of the first variable capacitance electromagnetic valve 5j is connected with the suction pipelines of the first variable capacitance compressor 8a and the second variable capacitance compressor 8b, and the other end is connected with the variable capacitance ports of the first variable capacitance compressor 8a and the second variable capacitance compressor 8 b;

one end of the second variable capacitance electromagnetic valve 5k is connected with the exhaust pipelines of the first variable capacitance compressor 8a and the second variable capacitance compressor 8b, and the other end is connected with the variable capacitance ports of the first variable capacitance compressor 8a and the second variable capacitance compressor 8 b;

the control device 18 can also be used for controlling the first variable-capacity electromagnetic valve 5j to be closed and the second variable-capacity electromagnetic valve 5k to be opened under the condition that the system needs three-cylinder operation; and under the condition that the system needs double-cylinder operation, the first variable-capacity electromagnetic valve 5j is controlled to be opened, and the second variable-capacity electromagnetic valve 5k is controlled to be closed.

The compressor variable volume system of the embodiment of the invention adopts a three-cylinder or two-cylinder operation mode mainly according to the load change of the system, thereby achieving the most efficient and energy-saving operation state.

In an embodiment of the present invention, as shown in fig. 3 and 4, the outer unit system 17 may further include a compressor oil circuit system, wherein:

the compressor oil circuit system may include an oil separator 9 and an oil-equalizing solenoid valve 5m, wherein:

the air inlet pipe of the oil separator 9 is connected with the air outlet pipeline of the compressor, and the air inlet pipe of the oil separator 9 is also connected with an oil equalizing pipe at the bottom of the compressor through an oil equalizing electromagnetic valve 5 m.

The control device 18 can also be used to control the oil-equalizing solenoid valve 5m to open in the case where the compressor oil level exceeds the position of the oil-equalizing hole at the bottom of the compressor.

Therefore, the compressor oil path system of the above embodiment of the present invention discharges the excessive oil in the compressor to the air inlet pipe of the oil separator 9 through the bottom oil equalizing pipe of the compressor, the one-way valve 6e/6f and the electromagnetic valve 5m, the oil separator 9 separates the mixture of the high-pressure gaseous refrigerant and the oil, and the oil is stored at the bottom of the oil separator 9.

In an embodiment of the present invention, the compressor oil circuit system may further include a first oil return solenoid valve 5o, a second oil return solenoid valve 5n, and a third oil return solenoid valve 5l, wherein:

the first oil return electromagnetic valve 5o is arranged in a pipeline between an oil return pipe at the bottom of the oil separator 9 and a compressor suction port; the second oil return electromagnetic valve 5n is arranged in a pipeline between an oil outlet pipe at the bottom of the gas-liquid separator and an air suction port of the compressor; the third oil return solenoid valve 5l is arranged in a pipeline between the air outlet of the compressor and the air outlet of the oil separator 9.

The control device 18 can also be used for controlling the first oil return electromagnetic valve 5o to be opened under the condition that the system is in operation, so that the oil at the bottom of the oil separator returns to the suction side of the compressor through the bottom oil return pipe, the filter 3c, the capillary tube 12e and the electromagnetic valve 5o, and the probability of oil shortage of the compressor is reduced.

The control device 18 can also be used to control the second oil return solenoid valve 5n and the third oil return solenoid valve 5l to open and the solenoid valve 5m to close in the case of oil shortage in the compressor, thereby controlling the system to return oil quickly.

Fig. 6 is a schematic diagram illustrating a control method of a multi-split air conditioner according to a first embodiment of the invention. Preferably, the present embodiment may be performed by the multi-split air conditioning control apparatus of the present invention. As shown in fig. 6, the method may include:

and step 61, acquiring the working mode of the internal machine system 15.

And step 62, controlling the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b to be in corresponding working states according to the working mode of the indoor unit system 15, wherein the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b are connected with the indoor unit system 15 through refrigerant pipelines, and the working states comprise acting as condensers, acting as condensers and not participating in refrigerant circulation.

In one embodiment of the present invention, step 62 may comprise: the control of the working state of the first outdoor heat exchanger 1a and the working state of the second outdoor heat exchanger 1b is realized by controlling the opening and closing of a refrigerant pipeline control valve, wherein the refrigerant pipeline control valve is arranged in a refrigerant pipeline, and the refrigerant pipeline control valve comprises at least one of a four-way valve, an electronic expansion valve and an electromagnetic valve.

In an embodiment of the present invention, step 62 may specifically include:

and step 621, controlling the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b to serve as evaporators when the indoor unit system 15 is in the complete heating mode.

In step 622, when the indoor unit system 15 is in the main heating mode or the small load heating mode, the first outdoor heat exchanger 1a is controlled to serve as an evaporator, and the second outdoor heat exchanger 1b is controlled to serve as a condenser.

Step 623, controlling the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b to function as condensers when the indoor unit system 15 is in the full cooling mode.

In step 624, the internal machine system 15 is in the main cooling mode, and the first outdoor heat exchanger 1a is controlled to function as a condenser, and the second outdoor heat exchanger 1b functions as an evaporator.

Step 625, the first outdoor heat exchanger 1a is controlled to serve as a condenser, and the second outdoor heat exchanger 1b does not participate in refrigerant circulation when the indoor unit system 15 is in the low-load refrigeration mode.

In step 626, the indoor unit system 15 is in the heat recovery mode, and the first outdoor heat exchanger 1a and the second outdoor heat exchanger 1b are controlled not to participate in the refrigerant circulation.

Based on the heat recovery multi-split air conditioner control method provided by the embodiment of the invention, the working state of the outdoor heat exchanger can be switched according to the working mode of the indoor unit system (for example, under the conditions of partial indoor unit refrigeration, partial indoor unit heating and extreme working condition) so as to ensure the load requirements of each indoor unit user, thereby improving the comfort of the user and the reliability of the unit; the embodiment of the invention can meet the requirement that the heating capacity is not attenuated at the low temperature of-20 ℃; the embodiment of the invention can meet the requirements of heating and small load of the main refrigeration body under the limit working condition, and ensure that the comfort of users is not attenuated.

Fig. 7 is a schematic diagram illustrating a control method of a multi-split air conditioner according to a second embodiment of the invention. Preferably, the present embodiment may be performed by the multi-split air conditioning control apparatus of the present invention. In addition to the method of the embodiment of fig. 6, the method may further include:

and step 71, under the condition that the compressor needs air supplement, controlling the air supplement electromagnetic valve 5f to be opened so as to control air path refrigerants of the subcooler 13 to enter the compressor for air supplement, wherein the subcooler 13 is connected with an air supplement port of the compressor through the air supplement electromagnetic valve 5 f.

And 72, under the condition that the compressor needs air supplement, controlling the air supplement amount of the compressor by controlling the opening degree of the air supplement electronic expansion valve 4c, wherein the air supplement electronic expansion valve 4c is arranged on an auxiliary path of the subcooler 13.

According to the embodiment of the invention, the system capacity and the energy efficiency ratio can be improved by adopting a gas-supplementing and enthalpy-increasing mode according to the changes of the system load, the environment temperature and the exhaust superheat degree.

Fig. 8 is a schematic diagram illustrating a control method of a multi-split air conditioner according to a third embodiment of the invention. Preferably, the present embodiment may be performed by the multi-split air conditioning control apparatus of the present invention. In addition to the method of the embodiment of fig. 6 or fig. 7, the method may further include:

and 81, under the condition that the compressor needs air supplement, controlling the supercooling regulating electromagnetic valve 5e to be closed, opening the air supplement electromagnetic valve 5f, and controlling air path refrigerants of the subcooler 13 to enter the compressor for air supplement, wherein the subcooler 13 is connected with an inlet of the low-pressure side gas-liquid separator through the supercooling regulating electromagnetic valve 5 e.

And step 82, under the condition that the compressor does not need air supplement, controlling the supercooling regulating electromagnetic valve 5e to be opened, closing the air supplement electromagnetic valve 5f, controlling the air path refrigerant of the subcooler 13 to enter the inlet of the low-pressure side gas-liquid separator, and regulating the supercooling degree of the unit.

And step 83, under the condition that the supercooling degree of the system needs to be adjusted, controlling the supercooling degree by controlling the opening degree of the air supply electronic expansion valve 4 c.

Or,

under the condition that the system needs to adjust the supercooling degree, the control of the supercooling degree is realized by controlling the opening degrees of the electronic expansion valve 4a of the first outdoor heat exchanger 1a and the electronic expansion valve 4b of the second outdoor heat exchanger 1b, wherein the subcooler 13 is connected with the first outdoor heat exchanger 1a through the electronic expansion valve 4a of the first outdoor heat exchanger 1a, and the subcooler 13 is connected with the second outdoor heat exchanger 1b through the electronic expansion valve 4b of the second outdoor heat exchanger 1 b.

According to the embodiment of the invention, when the supercooling degree of the unit is detected to be small, measures can be taken to increase the supercooling degree, so that the comfort requirement of a user is ensured.

Fig. 9 is a schematic diagram illustrating a control method for a multi-split air conditioner according to a fourth embodiment of the invention. Preferably, the present embodiment may be performed by the multi-split air conditioning control apparatus of the present invention. In addition to the method of any of the embodiments of fig. 6-8, the method may further include:

and step 91, under the condition that the system needs three-cylinder operation, controlling the first variable capacitance electromagnetic valve 5j to be closed and the second variable capacitance electromagnetic valve to be opened, and switching the compressor to a three-cylinder operation state, wherein the compressor comprises a first variable capacitance compressor 8a and a second variable capacitance compressor 8b which are connected in parallel.

And step 92, under the condition that the system needs to operate by two cylinders, controlling the first variable-capacity electromagnetic valve 5j to be opened and the second variable-capacity electromagnetic valve to be closed.

The embodiment of the invention can adopt a three-cylinder or two-cylinder operation mode according to the change of the system load, thereby achieving the most efficient and energy-saving operation state.

Fig. 10 is a schematic diagram illustrating a control method for a multiple on-line air conditioner according to a fifth embodiment of the invention. Preferably, the present embodiment may be performed by the multi-split air conditioning control apparatus of the present invention. In addition to the method of any of the embodiments of fig. 6-9, the method may further include:

step 101, under the condition that the oil level of the compressor exceeds the position of an oil equalizing hole at the bottom of the compressor, controlling an oil equalizing electromagnetic valve 5m to be opened, wherein an air inlet pipe of an oil separator 9 is connected with an air outlet pipeline of the compressor, and the air inlet pipe of the oil separator 9 is also connected with an oil equalizing pipe at the bottom of the compressor through the oil equalizing electromagnetic valve 5 m.

And 102, under the condition that the system runs, controlling the first oil return electromagnetic valve 5o to be opened so that oil at the bottom of the oil separator returns to the suction side of the compressor through the bottom oil return pipe, the filter 3c, the capillary tube 12e and the electromagnetic valve 5o, and reducing the probability of oil shortage of the compressor, wherein the first oil return electromagnetic valve 5o is arranged in a pipeline between the bottom oil return pipe of the oil separator 9 and the suction port of the compressor.

And 103, under the condition that the compressor is lack of oil, controlling a second oil return electromagnetic valve 5n and a third oil return electromagnetic valve 5l to be opened, closing an electromagnetic valve 5m, and controlling the system to return oil quickly, wherein the second oil return electromagnetic valve 5n is arranged in a pipeline between an oil outlet pipe at the bottom of the gas-liquid separator and an air suction port of the compressor, and the third oil return electromagnetic valve 5l is arranged in a pipeline between an air outlet of the compressor and an air outlet of the oil separator 9.

According to the embodiment of the invention, the redundant oil in the compressor can be discharged to the air inlet pipe of the oil separator 9 through the oil equalizing pipe at the bottom of the compressor, the one-way valve 6e/6f and the electromagnetic valve 5m, the oil separator 9 separates the mixture of the high-pressure gaseous refrigerant and the oil, and the oil is stored at the bottom of the oil separator 9.

Fig. 11 is a schematic diagram of an embodiment of the multi-split air conditioner control device according to the present invention. As shown in fig. 11, the multi-split air conditioner control device includes a memory 111 and a processor 112, wherein:

a memory 111 for storing instructions.

The processor 112 is configured to execute the instructions, so that the apparatus performs operations for implementing the control method of the multi-split air conditioner according to any of the above embodiments, where the instructions may include an acquisition instruction for acquiring an operating mode of the internal machine system 15, and a control instruction for controlling the on/off of a refrigerant pipeline control valve such as a four-way valve, an electronic expansion valve, and a solenoid valve.

In an embodiment of the present invention, the multi-split air conditioner control device may be the control device 18 in the embodiment of fig. 1 or fig. 2.

Based on the heat recovery multi-online air conditioning control device provided by the embodiment of the invention, the working state of the outdoor heat exchanger can be switched according to the working mode of the indoor unit system (for example, under the conditions of partial indoor unit refrigeration, partial indoor unit heating and extreme working condition) so as to ensure the load requirements of each indoor unit user, thereby improving the comfort of the user and the reliability of the unit; the embodiment of the invention can meet the requirement that the heating capacity is not attenuated at the low temperature of-20 ℃; the embodiment of the invention can meet the requirements of heating and small load of the main refrigeration body under the limit working condition, and ensure that the comfort of users is not attenuated.

The control device 18 described above may be implemented as a general purpose processor, a Programmable Logic Controller (PLC), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any suitable combination thereof, for performing the functions described herein.

Thus far, the present invention has been described in detail. Some details well known in the art have not been described in order to avoid obscuring the concepts of the present invention. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, where the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.

The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to practitioners skilled in this art. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. An outdoor unit of a multi-split air conditioner, comprising an outdoor unit system (17) and a control device (18), wherein the outdoor unit system (17) comprises a first outdoor heat exchanger (1a) and a second outdoor heat exchanger (1b), wherein:

the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) are connected with an indoor unit system (15) through refrigerant pipelines;

the control device (18) is respectively electrically connected with the internal machine system (15) and the external machine system (17);

the control device (18) is used for controlling the working states of the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) according to the working mode of the indoor unit system (15), wherein the working states comprise the function of a condenser, the function of an evaporator and the non-participation in refrigerant circulation.

2. The outdoor unit of claim 1,

the control device (18) is used for controlling the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) to act as evaporators when the indoor machine system (15) is in a complete heating mode;

or,

controlling the first outdoor heat exchanger (1a) to act as an evaporator and the second outdoor heat exchanger (1b) to act as a condenser when the indoor unit system (15) is in a main heating mode or a small load heating mode;

or,

controlling the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) to act as condensers when the indoor unit system (15) is in a full cooling mode;

or,

controlling the first outdoor heat exchanger (1a) to act as a condenser and the second outdoor heat exchanger (1b) to act as an evaporator when the internal machine system (15) is in a main body refrigeration mode;

or,

when the internal machine system (15) is in a small-load refrigeration mode, the first outdoor heat exchanger (1a) is controlled to serve as a condenser, and the second outdoor heat exchanger (1b) does not participate in refrigerant circulation;

or,

and controlling the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) not to participate in refrigerant circulation when the indoor unit system (15) is in a heat recovery mode.

3. The outdoor unit of claim 1, further comprising a refrigerant line control valve, wherein:

the control device (18) is used for controlling the working state of the first outdoor heat exchanger (1a) and the working state of the second outdoor heat exchanger (1b) by controlling the opening and closing of the refrigerant pipeline control valve.

4. The outdoor unit of claim 3, wherein the refrigerant line control valve comprises an electronic expansion valve (4a) of the first outdoor heat exchanger (1a) and an electronic expansion valve (4b) of the second outdoor heat exchanger (1b), wherein:

an electronic expansion valve (4a) of the first outdoor heat exchanger (1a) is connected with the first outdoor heat exchanger (1a), and an electronic expansion valve (4b) of the second outdoor heat exchanger (1b) is connected with the second outdoor heat exchanger (1 b);

the control device (18) is used for controlling the opening degrees of the electronic expansion valve (4a) of the first outdoor heat exchanger (1a) and the electronic expansion valve (4b) of the second outdoor heat exchanger (1b) to be 0 when the indoor unit system (15) is in a heat recovery mode so as to control the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) not to participate in refrigerant circulation, so that low-pressure refrigerant flowing out of the refrigerating indoor unit is returned to the heating indoor unit after being processed by a compressor of the outdoor unit system (17);

the control device (18) is used for controlling the opening degree of the electronic expansion valve (4b) of the second outdoor heat exchanger (1b) to be 0 so as to control the second outdoor heat exchanger (1b) not to participate in refrigerant circulation when the indoor machine system (15) is in a small-load heating mode.

5. The outdoor unit of any one of claims 1 to 4, further comprising a compressor, a gas make-up solenoid valve (5f), and a subcooler (13), wherein:

the subcooler (13) is connected with the air supplement port of the compressor through an air supplement electromagnetic valve (5 f); the control device (18) is electrically connected with the air replenishing electromagnetic valve (5 f);

the control device (18) is also used for controlling the air supplement electromagnetic valve (5f) to be opened under the condition that the compressor needs air supplement so as to control air path refrigerant of the subcooler (13) to enter the compressor for air supplement.

6. The outdoor unit of claim 5, further comprising an air make-up electronic expansion valve (4c), wherein:

the air supply electronic expansion valve (4c) is arranged on a bypass of the subcooler (13), and the control device (18) is electrically connected with the air supply electronic expansion valve (4 c);

the control device (18) is also used for controlling the air supplement amount of the compressor by controlling the opening degree of the air supplement electronic expansion valve (4c) under the condition that the compressor needs air supplement.

7. The outdoor unit of claim 6, further comprising a supercooling regulating solenoid valve (5e), wherein:

the subcooler (13) is connected with the inlet of the low-pressure side gas-liquid separator through a subcooling regulating electromagnetic valve (5 e); the control device (18) is electrically connected with the supercooling regulating electromagnetic valve (5 e);

the control device (18) is also used for controlling the supercooling regulating electromagnetic valve (5e) to be closed and the gas supplementing electromagnetic valve (5f) to be opened under the condition that the compressor needs gas supplementing, and controlling a gas path refrigerant of the subcooler (13) to enter the compressor for gas supplementing; and under the condition that the compressor does not need air supplement, controlling the supercooling regulating electromagnetic valve (5e) to be opened, closing the air supplement electromagnetic valve (5f), controlling the air path refrigerant of the subcooler (13) to enter the inlet of the low-pressure side gas-liquid separator, and regulating the supercooling degree of the unit.

8. The outdoor unit of claim 7, further comprising an electronic expansion valve (4a) of the first outdoor heat exchanger (1a) and an electronic expansion valve (4b) of the second outdoor heat exchanger (1b), wherein:

the subcooler (13) is connected with the first outdoor heat exchanger (1a) through an electronic expansion valve (4a) of the first outdoor heat exchanger (1 a); the subcooler (13) is connected with the second outdoor heat exchanger (1b) through an electronic expansion valve (4b) of the second outdoor heat exchanger (1 b);

the control device (18) is also used for controlling the supercooling degree by controlling the opening degree of the air supply electronic expansion valve (4c) under the condition that the supercooling degree of the system needs to be adjusted; or, when the system needs to adjust the supercooling degree, the opening degree of the electronic expansion valve (4a) of the first outdoor heat exchanger (1a) and the opening degree of the electronic expansion valve (4b) of the second outdoor heat exchanger (1b) are controlled to realize the control of the supercooling degree.

9. The outdoor unit of any one of claims 1 to 4, further comprising a first variable capacity solenoid valve (5j) and a second variable capacity solenoid valve (5k), the compressor comprising a first variable capacity compressor (8a) and a second variable capacity compressor (8b), wherein:

a first variable capacity compressor (8a) and a second variable capacity compressor (8b) are connected in parallel;

one end of the first variable capacitance electromagnetic valve (5j) is connected with the suction pipelines of the first variable capacitance compressor (8a) and the second variable capacitance compressor (8b), and the other end of the first variable capacitance electromagnetic valve is connected with the variable capacitance ports of the first variable capacitance compressor (8a) and the second variable capacitance compressor (8 b);

one end of the second variable capacitance electromagnetic valve (5k) is connected with the exhaust pipelines of the first variable capacitance compressor (8a) and the second variable capacitance compressor (8b), and the other end is connected with the variable capacitance ports of the first variable capacitance compressor (8a) and the second variable capacitance compressor (8 b);

the control device (18) is also used for controlling the first variable-capacity electromagnetic valve (5j) to be closed and the second variable-capacity electromagnetic valve (5k) to be opened under the condition that the system needs three-cylinder operation; and under the condition that the system needs double-cylinder operation, the first variable-capacity electromagnetic valve (5j) is controlled to be opened, and the second variable-capacity electromagnetic valve (5k) is controlled to be closed.

10. The outdoor unit of any one of claims 1 to 4, further comprising an oil separator (9) and an oil-equalizing solenoid valve (5m), wherein:

the air inlet pipe of the oil separator (9) is connected with the air outlet pipeline of the compressor, and the air inlet pipe of the oil separator (9) is also connected with an oil equalizing pipe at the bottom of the compressor through an oil equalizing electromagnetic valve (5 m);

the control device (18) is also used for controlling the oil-equalizing electromagnetic valve (5m) to be opened under the condition that the oil level of the compressor exceeds the position of an oil-equalizing hole at the bottom of the compressor.

11. The outdoor unit of any one of claims 1 to 4, further comprising a first oil return solenoid valve (5o), a second oil return solenoid valve (5n), and a third oil return solenoid valve (5l), wherein:

the first oil return electromagnetic valve (5o) is arranged in a pipeline between an oil return pipe at the bottom of the oil separator (9) and a compressor suction port; the second oil return electromagnetic valve (5n) is arranged in a pipeline between an oil outlet pipe at the bottom of the gas-liquid separator and an air suction port of the compressor; the third oil return electromagnetic valve (5l) is arranged in a pipeline between the air outlet of the compressor and the air outlet of the oil separator (9);

the control device (18) is also used for controlling the first oil return electromagnetic valve (5o) to be opened under the condition that the system is operated; and controlling the second oil return electromagnetic valve (5n) and the third oil return electromagnetic valve (5l) to be opened under the condition that the compressor is lack of oil.

12. A multi-split air conditioner characterized by comprising an indoor unit system (15), and an outdoor unit according to any one of claims 1 to 11.

13. A multi-split air conditioner as claimed in claim 12, further comprising a mode converter (16), wherein:

the mode converter (16) is respectively connected with the internal machine system (15) and the external machine system (17) through refrigerant pipelines;

and the mode converter (16) is used for distributing corresponding refrigerants to each internal machine according to the mode requirement of each internal machine and conveying the refrigerants returned by the internal machine system (15) to the external machine system (17).

14. A control method of a multi-split air conditioner is characterized by comprising the following steps:

acquiring the working mode of an internal machine system (15);

and controlling the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) to be in corresponding working states according to the working mode of the indoor unit system (15), wherein the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) are connected with the indoor unit system (15) through refrigerant pipelines, and the working states comprise a condenser, a condenser and a refrigerant circulation failure.

15. The method according to claim 14, wherein said controlling the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) in respective operating states according to the operating mode of the internal machine system (15) comprises:

controlling the first outdoor heat exchanger (1a) and the second outdoor heat exchanger (1b) to act as evaporators when the indoor unit system (15) is in a complete heating mode;

16. Method according to claim 15, wherein said controlling the first and second outdoor heat exchangers (1a, 1b) in respective operating conditions comprises:

the control of the working state of the first outdoor heat exchanger (1a) and the working state of the second outdoor heat exchanger (1b) is realized by controlling the opening and closing of a refrigerant pipeline control valve, wherein the refrigerant pipeline control valve is arranged in a refrigerant pipeline, and the refrigerant pipeline control valve comprises at least one of a four-way valve, an electronic expansion valve and an electromagnetic valve.

17. The method according to any one of claims 14-16, further comprising:

under the condition that the compressor needs air supplement, the air supplement electromagnetic valve (5f) is controlled to be opened so as to control air path refrigerants of the subcooler (13) to enter the compressor for air supplement, wherein the subcooler (13) is connected with an air supplement port of the compressor through the air supplement electromagnetic valve (5 f).

18. The method of claim 17, further comprising:

under the condition that the compressor needs air supplement, the air supplement amount of the compressor is controlled by controlling the opening degree of an air supplement electronic expansion valve (4c), wherein the air supplement electronic expansion valve (4c) is arranged on a bypass of the subcooler (13).

19. The method of claim 18, further comprising:

under the condition that the compressor needs air supplement, the supercooling regulating electromagnetic valve (5e) is controlled to be closed, the air supplement electromagnetic valve (5f) is controlled to be opened, air path refrigerants of the subcooler (13) are controlled to enter the compressor for air supplement, wherein the subcooler (13) is connected with an inlet of the low-pressure side gas-liquid separator through the supercooling regulating electromagnetic valve (5 e);

under the condition that the compressor does not need air supplement, the supercooling regulating electromagnetic valve (5e) is controlled to be opened, the air supplement electromagnetic valve (5f) is controlled to be closed, air path refrigerants of the subcooler (13) are controlled to enter an inlet of the low-pressure side gas-liquid separator, and the supercooling degree of the unit is regulated.

20. The method of claim 19, further comprising:

under the condition that the supercooling degree of the system needs to be adjusted, the opening degree of the air supply electronic expansion valve (4c) is controlled to realize the control of the supercooling degree;

or,

under the condition that the supercooling degree of the system needs to be adjusted, the supercooling degree is controlled by controlling the opening degrees of an electronic expansion valve (4a) of a first outdoor heat exchanger (1a) and an electronic expansion valve (4b) of a second outdoor heat exchanger (1b), wherein a subcooler (13) is connected with the first outdoor heat exchanger (1a) through the electronic expansion valve (4a) of the first outdoor heat exchanger (1a), and the subcooler (13) is connected with the second outdoor heat exchanger (1b) through the electronic expansion valve (4b) of the second outdoor heat exchanger (1 b).

21. The method according to any one of claims 14-16, further comprising:

under the condition that the system needs three-cylinder operation, a first variable capacitance electromagnetic valve (5j) is controlled to be closed, a second variable capacitance electromagnetic valve (5k) is controlled to be opened, and the compressor is switched to a three-cylinder operation state, wherein the compressor comprises a first variable capacitance compressor (8a) and a second variable capacitance compressor (8b) which are connected in parallel;

and under the condition that the system needs double-cylinder operation, the first variable capacitance electromagnetic valve (5j) is controlled to be opened, and the second variable capacitance electromagnetic valve (5k) is controlled to be closed.

22. The method according to any one of claims 14-16, further comprising:

and under the condition that the oil level of the compressor exceeds the position of an oil equalizing hole at the bottom of the compressor, controlling the oil equalizing electromagnetic valve (5m) to be opened, wherein the air inlet pipe of the oil separator (9) is connected with the air outlet pipeline of the compressor, and the air inlet pipe of the oil separator (9) is also connected with the oil equalizing pipe at the bottom of the compressor through the oil equalizing electromagnetic valve (5 m).

23. The method according to any one of claims 14-16, further comprising:

under the condition of system operation, controlling a first oil return electromagnetic valve (5o) to be opened, wherein the first oil return electromagnetic valve (5o) is arranged in a pipeline between an oil return pipe at the bottom of an oil separator (9) and a compressor suction port;

and under the condition that the compressor is lack of oil, controlling a second oil return electromagnetic valve (5n) and a third oil return electromagnetic valve (5l) to be opened, wherein the second oil return electromagnetic valve (5n) is arranged in a pipeline between an oil outlet pipe at the bottom of the gas-liquid separator and an air suction port of the compressor, and the third oil return electromagnetic valve (5l) is arranged in a pipeline between an air outlet of the compressor and an air outlet of the oil separator (9).

24. A multi-split air conditioner control device, comprising a memory (111) and a processor (112), wherein:

a memory (111) for storing instructions;

a processor (112) for executing the instructions to cause the apparatus to perform operations to implement the multi-split air conditioner control method according to any one of claims 14 to 23.