CN111442510B

CN111442510B - Multi-split air conditioning system, control method and control device thereof, and storage medium

Info

Publication number: CN111442510B
Application number: CN202010271829.0A
Authority: CN
Inventors: 丁云霄; 胡亚飞; 罗彬�; 谭志军
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: 2020-04-08
Filing date: 2020-04-08
Publication date: 2022-08-23
Anticipated expiration: 2040-04-08
Also published as: CN111442510A

Abstract

The invention discloses a multi-split air conditioning system and a control method, a control device and a storage medium thereof, wherein the control method comprises the following steps: respectively detecting the current working states of N internal machines in the multi-split air conditioning system; if two internal machines in the current N internal machines are in working states, the first internal machine is in a cooling operation mode, and the second internal machine is in a heating operation mode, detecting the current operation mode of the external machine; if the outdoor unit is in the refrigeration mode at present, adjusting the operation mode of the outdoor unit according to the operation mode of the first indoor unit; and if the outdoor unit is in the heating mode currently, adjusting the operation mode of the outdoor unit according to the operation mode of the second indoor unit. The control method adjusts the operation mode of the outer unit according to the current operation modes of the N inner units of the multi-split air conditioning system and the current operation mode of the outer unit, and can avoid the problem of frequent fluctuation of the operation mode of the system, so that the system is in a long-term stable operation state, the operation reliability of the system is ensured, and the comfort of users is improved.

Description

Multi-split air conditioning system, control method and control device thereof, and storage medium

Technical Field

The invention relates to the technical field of air conditioners, in particular to a multi-split air conditioner system, a control method, a control device and a storage medium thereof.

Background

At present, an existing multi-split air conditioning system, such as a heat recovery multi-split air conditioning system, mainly includes: the main difference between the two-pipe heat recovery type multi-split air conditioning system and the three-pipe heat recovery type multi-split air conditioning system is that two pipes or three pipes are arranged in a main pipe of a refrigerant flow direction switching device (MS device for short) between an external machine and an internal machine. For the three-pipe heating recovery type multi-split air conditioning system, the outdoor heat exchanger can be designed into a single piece or a plurality of pieces, the single piece of outdoor heat exchanger can only be used as a single purpose, namely, only can be used as a condenser or an evaporator, different pieces of heat exchangers of the plurality of pieces of outdoor heat exchangers are mutually independent, and each piece of outdoor heat exchanger can be used as the condenser or the evaporator, so that the plurality of pieces of outdoor heat exchangers can have the state that the condenser and the evaporator coexist integrally, and the single piece of outdoor heat exchanger does not have the state that the condenser and the evaporator coexist integrally.

When the outdoor heat exchanger is a single block and only one indoor unit in the system operates in a cooling mode and one indoor unit in the system operates in a heating mode, the outdoor heat exchanger can be used as a condenser or an evaporator, and if the system is in a main cooling mode, the outdoor heat exchanger is used as the condenser; if the system is in the main heating mode, the outdoor heat exchanger functions as an evaporator. In actual operation, the external environment or the system state changes slightly, which easily causes frequent fluctuation of the outdoor heat exchanger between the condenser and the evaporator, and further causes frequent switching of the operation mode of the multi-split air-conditioning system between the main cooling mode and the main heating mode, thereby affecting the operation reliability and stability of the system and lowering the comfort of users.

Disclosure of Invention

The present invention is directed to solving, at least in part, one of the technical problems in the related art. Therefore, a first object of the present invention is to provide a control method for a multi-split air conditioning system, which adjusts an operation mode of an external unit according to current operation modes of N internal units and the current operation mode of the external unit of the multi-split air conditioning system, and can avoid a problem of frequent fluctuation of the operation mode of the system, so that the system is in a long-term stable operation state, reliability of system operation is ensured, and comfort of a user is improved.

A second object of the invention is to propose a computer-readable storage medium.

A third object of the present invention is to provide a control apparatus for a multi-split air conditioning system.

A fourth object of the present invention is to provide a multi-split air conditioning system.

In order to achieve the above object, a first embodiment of the present invention provides a method for controlling a multi-split air conditioning system, where the multi-split air conditioning system includes an external unit and N internal units, where N is an integer greater than or equal to 2, and the method includes: respectively detecting the current working states of N internal machines in the multi-split air conditioning system; if two internal machines in the N internal machines are in working states, a first internal machine is in a cooling operation mode, and a second internal machine is in a heating operation mode, detecting the current operation mode of the external machine; if the outdoor unit is in the refrigeration mode currently, adjusting the operation mode of the outdoor unit according to the operation mode of the first indoor unit; and if the outer machine is in the heating mode currently, adjusting the operation mode of the outer machine according to the operation mode of the second inner machine.

According to the control method of the multi-split air conditioning system, the current working states of N internal machines in the multi-split air conditioning system are detected, then when two internal machines in the current N internal machines are detected to be in working states, a first internal machine is in a refrigerating operation mode, and a second internal machine is in a heating operation mode, the current operation mode of an external machine is detected, and if the external machine is in the refrigerating mode, the operation mode of the external machine is adjusted according to the operation mode of the first internal machine; and if the outdoor unit is in the heating mode currently, adjusting the operation mode of the outdoor unit according to the operation mode of the second indoor unit. Therefore, the method adjusts the operation mode of the outer unit according to the current operation modes of the N inner units and the current operation mode of the outer unit of the multi-split air conditioning system, and can avoid the problem of frequent fluctuation of the operation mode of the system, so that the system is in a long-term stable operation state, the operation reliability of the system is ensured, and the comfort of users is improved.

In addition, the control method of the multi-split air conditioning system according to the above embodiment of the present invention may further have the following additional technical features:

according to an embodiment of the present invention, the adjusting the operation mode of the outer unit according to the operation mode of the first inner unit includes: if the first internal machine is changed from a refrigeration operation mode to a non-refrigeration operation mode, adjusting the external machine from the refrigeration mode to a heating mode; wherein, the non-refrigeration operation mode comprises any one of the following modes: shutdown, shutdown to temperature, forced shutdown to prevent freezing and heating mode.

According to an embodiment of the present invention, the adjusting of the operation mode of the outer unit according to the operation mode of the first inner unit includes: if the first internal machine maintains the refrigeration operation mode, judging whether the current operation state of the multi-split air conditioning system meets the following first conditions: the time difference between the previous operation mode adjustment time of the external unit and the current time is larger than a first time threshold, the absolute value of the difference between the saturated condensing temperature corresponding to the current condensing pressure and the saturated condensing temperature corresponding to the condensing pressure at the previous time is smaller than a first temperature threshold, and the duration of the lowest wind shield of the external unit is larger than a second time threshold; if the current operation state of the multi-split air-conditioning system meets the first conditions, judging whether the duration of the saturated condensing temperature corresponding to the current condensing pressure of the multi-split air-conditioning system, which is smaller than a second temperature threshold, is larger than a third time threshold; and if so, adjusting the outdoor unit from a cooling mode to a heating mode.

According to an embodiment of the present invention, after determining whether the saturated condensing temperature corresponding to the current condensing pressure of the multi-split air conditioning system is less than the second temperature threshold and the duration is greater than the third time threshold, the method further includes: if not, judging whether the duration of the saturated condensing temperature corresponding to the current condensing pressure of the multi-split air-conditioning system, which is smaller than a third temperature threshold, is greater than a fourth time threshold and whether the duration of the saturated evaporating temperature corresponding to the current evaporating pressure, which is smaller than a fourth temperature threshold, is greater than a fifth time threshold, wherein the third temperature threshold is greater than the second temperature threshold and the third time threshold is greater than the fourth time threshold; and if so, adjusting the outdoor unit from a cooling mode to a heating mode.

According to an embodiment of the present invention, the adjusting the operation mode of the outer unit according to the operation mode of the second inner unit includes: if the second internal machine is changed from the heating operation mode to the non-heating operation mode, adjusting the external machine from the heating mode to the cooling mode; wherein, the non-heating operation mode comprises any one of the following modes: shutdown, temperature-reaching shutdown and refrigeration mode.

According to an embodiment of the present invention, the adjusting the operation mode of the outer unit according to the operation mode of the second inner unit includes: if the second internal machine maintains the heating operation mode, judging whether the current operation state of the multi-split air conditioner system meets the following second conditions: the time difference between the previous operation mode adjustment moment and the current moment of the external machine is greater than a first time threshold, the absolute value of the difference between the saturated evaporation temperature corresponding to the current evaporation pressure and the saturated evaporation temperature corresponding to the evaporation pressure at the previous moment is smaller than a fifth temperature threshold, and the duration of the lowest wind shield of the external machine is greater than a sixth time threshold; if the current operating state of the multi-split air-conditioning system meets the second conditions, judging whether the current operating state of the multi-split air-conditioning system meets the following third conditions: whether the duration that the saturated condensing temperature corresponding to the current condensing pressure is greater than the sixth temperature threshold is greater than a seventh time threshold, whether the duration that the saturated evaporating temperature corresponding to the current evaporating pressure is greater than the seventh temperature threshold is greater than an eighth time threshold, and whether the duration that the frequency of the compressor in the outdoor unit is less than the frequency threshold is greater than a ninth time threshold; and if the current operation state of the multi-split air-conditioning system meets the third conditions, adjusting the outdoor unit from a heating mode to a cooling mode.

According to an embodiment of the present invention, the method for controlling a multi-split air conditioning system further includes: acquiring a starting instruction, wherein the starting instruction comprises an instruction for instructing the first internal machine to start a cooling operation mode and an instruction for instructing the second internal machine to start a heating operation mode; and determining the starting operation mode of the external machine according to the starting operation mode and the capacity of the first internal machine and the starting operation mode and the capacity of the second internal machine.

In order to achieve the above object, a second aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, where the computer program, when executed by a processor, implements the method for controlling a multi-split air conditioning system according to the first aspect of the present invention.

The computer readable storage medium of the embodiment of the invention can avoid the problem of frequent fluctuation of the system operation mode when the computer program stored on the computer readable storage medium is executed by the processor, thereby enabling the system to be in a long-term stable operation state, ensuring the reliability of the system operation and improving the comfort of users.

In order to achieve the above object, a third aspect of the present invention provides a control device for a multi-split air conditioning system, the multi-split air conditioning system including an external unit and N internal units, where N is an integer greater than or equal to 2, the control device comprising: the first detection module is used for respectively detecting the current working states of N internal machines in the multi-split air conditioning system; the second detection module is used for detecting the current operation mode of the external unit if two internal units in the N internal units are in working states, the first internal unit is in a cooling operation mode, and the second internal unit is in a heating operation mode; the control module is used for adjusting the operation mode of the outer machine according to the operation mode of the first inner machine if the outer machine is in the refrigeration mode currently; and the controller is used for adjusting the operation mode of the outer machine according to the operation mode of the second inner machine if the outer machine is in the heating mode currently.

According to the control device of the multi-split air conditioning system, the current working states of the N internal machines in the multi-split air conditioning system are respectively detected through the first detection module, when two of the current N internal machines are detected to be in the working states, the first internal machine is in the cooling operation mode, the second internal machine is in the heating operation mode, the current operation mode of the external machine is detected through the second detection module, the operation mode of the external machine is further adjusted through the control module according to the operation mode of the first internal machine when the external machine is in the cooling mode, and the operation mode of the external machine is adjusted through the control module according to the operation mode of the second internal machine when the external machine is in the heating mode. Therefore, the control device adjusts the operation mode of the outer unit according to the current operation modes of the N inner units and the current operation mode of the outer unit of the multi-split air conditioning system, and can avoid the problem of frequent fluctuation of the operation mode of the system, so that the system is in a long-term stable operation state, the operation reliability of the system is guaranteed, and the comfort of a user is improved.

In order to achieve the above object, a fourth aspect of the present invention provides a multi-split air conditioning system, which includes a control device of the multi-split air conditioning system provided in the third aspect of the present invention.

According to the multi-split air conditioning system provided by the embodiment of the invention, the control device of the multi-split air conditioning system adjusts the operation mode of the outer unit according to the current operation modes of the N inner units and the current operation mode of the outer unit of the multi-split air conditioning system, so that the problem of frequent fluctuation of the operation mode of the system can be avoided, the system is in a long-term stable operation state, the operation reliability of the system is ensured, and the comfort of a user is improved.

Drawings

Fig. 1 is a schematic view of a multi-split air conditioning system according to an embodiment of the present invention;

fig. 2 is a flowchart of a control method of a multi-split air conditioning system according to an embodiment of the present invention;

fig. 3 is a flowchart illustrating the adjustment of the operation mode of the outer unit when the first inner unit is in the cooling operation mode, the second inner unit is in the heating operation mode, and the current operation mode of the outer unit is the cooling mode according to an example of the present invention;

fig. 4 is a flowchart illustrating an adjustment of an operation mode of an outer unit when a first inner unit is in a cooling operation mode, a second inner unit is in a heating operation mode, and a current operation mode of the outer unit is in the heating operation mode according to an example of the present invention;

fig. 5 is a block diagram illustrating a configuration of a control apparatus of a multi-split air conditioning system according to an embodiment of the present invention;

fig. 6 is a block diagram of a multi-split air conditioning system according to an embodiment of the present invention.

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 drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

A multi-split air conditioning system, a control method thereof, a control device thereof, and a storage medium according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 is a schematic view of a multi-split air conditioning system according to an embodiment of the present invention. As shown in fig. 1, the multi-split air conditioning system includes an outer unit and N inner units (four inner units are shown in fig. 1: a first inner unit 1, a second inner unit 2, a third inner unit 3, and a fourth inner unit 4), where N is an integer greater than or equal to 2, the outer unit is provided with an outer unit electronic expansion valve EXVA, an electronic expansion valve EXV1 is provided corresponding to the first inner unit 1, an electronic expansion valve EXV2 is provided corresponding to the second inner unit 2, an electronic expansion valve EXV3 is provided corresponding to the third inner unit 3, and an electronic expansion valve EXV4 is provided corresponding to the fourth inner unit 4.

The multi-split air conditioning system according to the embodiment of the present invention is a heat recovery type multi-split air conditioning system, and referring to fig. 1, the system may be a three-pipe multi-split air conditioning system including an external machine side, an MS (refrigerant flow direction switching device between the external machine and the internal machine) side, and an internal machine side. It can be understood that three multi-split air conditioning system main pipes are provided, the three multi-split air conditioning system main pipes are respectively a liquid pipe, a high-pressure air pipe and a low-pressure air pipe from small to large according to the pipe diameter, the liquid pipe and the low-pressure air pipe can be used by an indoor unit (a refrigerating indoor unit) operating in a refrigerating mode, the liquid pipe and the high-pressure air pipe can be used by an indoor unit (a heating indoor unit) operating in a heating mode, the state of a refrigerant flowing in the liquid pipe is a liquid state or a gas-liquid two-phase state refrigerant in a high-pressure state after being condensed by a condenser, and the air pipe is selected according to the operating mode of the indoor unit, namely, a refrigerating electromagnetic valve or a heating electromagnetic valve in an MS device is opened according to the operating mode of the indoor unit to realize refrigeration or heating.

It can be understood that the operation modes of the multi-split air conditioning system may include a pure cooling mode (all turned-on internal machines are operated in a cooling mode), a pure heating mode (all turned-on internal machines are operated in a heating mode), a main cooling mode (a part of turned-on internal machines are operated in a cooling mode, another part of turned-on internal machines are operated in a heating mode, and an external machine is used as a condenser), and a main heating mode (a part of turned-on internal machines are operated in a cooling mode, another part of turned-on internal machines are operated in a heating mode, and an external machine is used as an evaporator), wherein the main cooling mode and the main heating mode may be collectively referred to as a mixed mode. For example, in the pure heating mode, if the four internal machines are all turned on, the first internal machine, the second internal machine, the third internal machine and the fourth internal machine are all heating internal machines; in the main heating mode, if the four internal machines are all started, the first internal machine can be a refrigerating internal machine, and the second internal machine, the third internal machine and the fourth internal machine are all heating internal machines; in the main cooling mode, if the four internal machines are all started, the first internal machine, the second internal machine and the third internal machine can be cooling internal machines, and the fourth internal machine is a heating internal machine; in the pure refrigeration mode, if the four inner machines are all started, the first inner machine, the second inner machine, the third inner machine and the fourth inner machine are all refrigeration inner machines.

It should be noted that, when the outdoor heat exchanger of the multi-split air-conditioning system is a single unit and operates in the main heating mode or the main cooling mode, if only one indoor unit operates in the cooling mode (cooling indoor unit) and one indoor unit operates in the heating mode (heating indoor unit) in the multi-split air-conditioning system, the operation mode that the outdoor unit initially enters (i.e., the starting operation mode of the outdoor unit) is determined according to the sequence of starting the cooling indoor unit and the heating indoor unit, for example, when the cooling indoor unit is started first and then the heating indoor unit is started, the operation mode that the outdoor unit initially enters is the heating operation mode, and after the cooling indoor unit, the heating indoor unit and the outdoor unit are all started, the operation mode of the outdoor unit is adjusted according to the control method of the multi-split air-conditioning system of the embodiment of the present invention.

Fig. 2 is a flowchart of a control method of a multi-split air conditioning system according to an embodiment of the present invention. As shown in fig. 2, the control method includes the steps of:

and S1, respectively detecting the current working states of the N internal machines in the multi-split air conditioning system.

The current working states of the N internal machines may include: the air conditioner is not in a working state (shutdown state), is in a working state and is in a cooling operation mode, and is in a working state and is in a heating operation mode.

Specifically, in the operation process of the multi-split air conditioning system, the current working states of the N internal machines can be detected in real time, and the current operation mode of each internal machine can be displayed by controlling a display screen of a remote controller of the multi-split air conditioning system, so that a user can conveniently check the current operation mode at any time.

And S2, if two internal machines in the current N internal machines are in working states, the first internal machine is in a cooling operation mode, and the second internal machine is in a heating operation mode, detecting the current operation mode of the external machine.

Specifically, only two indoor units (a first indoor unit and a second indoor unit) of N indoor units of the multi-split air conditioning system are detected to be in a working state, other indoor units are in a shutdown state, the first indoor unit in the working state is in a cooling operation mode, the second indoor unit is in a heating operation mode, namely the first indoor unit is used as an evaporator, the second indoor unit is used as a condenser, and then the current operation mode of the outdoor unit is detected, wherein the current operation mode of the outdoor unit comprises a heating mode and a cooling mode.

And S3, if the outdoor unit is in the cooling mode currently, adjusting the operation mode of the outdoor unit according to the operation mode of the first indoor unit.

Specifically, it should be noted that, if it is detected that the external unit is currently operated in the cooling mode, that is, the external unit is used as a condenser (that is, the outdoor heat exchanger of the external unit is used as a condenser), it is indicated that the multi-split air conditioning system is currently operated in the main cooling mode, and at this time, because the second internal unit and the external unit are both used as condensers and the first internal unit is used as an evaporator, the main cooling mode is equivalent to increasing the condensers and correspondingly decreasing the evaporators compared with the pure cooling mode, especially when the capacity of the first internal unit used as an evaporator is small, at this time, the operation principle of the multi-split air conditioning system is as follows: one part of the high-temperature and high-pressure gaseous refrigerant compressed by the compressor is condensed by the outdoor heat exchanger, the other part of the high-temperature and high-pressure gaseous refrigerant is condensed by the second internal machine, the two condensed high-pressure liquid refrigerants are converged and then flow to the electronic expansion valve corresponding to the first internal machine through the MS cold cooling plate to perform throttling and pressure reduction, the low-temperature and low-pressure gas-liquid two-phase refrigerant subjected to throttling and pressure reduction is evaporated into a low-temperature gaseous refrigerant by the first internal machine, then flows back to the compressor through the gas-liquid separator to be continuously compressed into high-temperature and high-pressure gaseous refrigerant, and then flows to the condenser (the outdoor heat exchanger and the second internal machine), and the cycle operation is performed, so that the main refrigeration mode of the multi-split air-conditioning system is realized.

In the main refrigeration operation process, after the compressor enters PI (Proportional Integral) control, frequent fluctuation of the outdoor heat exchanger between the condenser and the evaporator is easily caused due to slight change of external environment temperature or system state, and further the working state of the first internal machine is changed, so that the operation mode of the first internal machine needs to be detected in real time, the operation mode of the external machine is adjusted according to the operation mode of the first internal machine, the operation mode of the external machine can be adjusted to a heating mode, frequent fluctuation of the external machine between the condenser and the evaporator is avoided, and the system is stably operated.

After the operation mode of the external unit is adjusted to the heating mode, the multi-split air conditioning system may operate in the pure heating mode or the main heating mode, so that switching of the multi-split air conditioning system from the main cooling mode to the pure heating mode or from the main cooling mode to the main heating mode can be realized.

And S4, if the outdoor unit is in the heating mode currently, adjusting the operation mode of the outdoor unit according to the operation mode of the second indoor unit.

Specifically, it should be noted that, if it is detected that the external unit is currently operated in the heating mode, that is, the external unit is used as an evaporator (that is, the outdoor heat exchanger of the external unit is used as an evaporator), it is indicated that the multi-split air conditioning system is currently operated in the main heating mode, and at this time, because the first internal unit and the external unit are both used as an evaporator and the second internal unit is used as a condenser, the main heating mode is equivalent to increasing the evaporator and correspondingly decreasing the condenser compared to the pure heating mode, especially when the capacity of the second internal unit used as a condenser is small, at this time, the operation principle of the multi-split air conditioning system is as follows: the high-temperature high-pressure gaseous refrigerant compressed by the compressor is condensed by the second inner machine, the condensed high-pressure liquid refrigerant is divided into two parts at the MS, one part of the high-pressure liquid refrigerant flows to the electronic expansion valve of the outer machine for throttling and depressurization, the low-temperature low-pressure gas-liquid two-phase refrigerant after throttling and depressurization is evaporated into a low-temperature gaseous refrigerant by the outdoor heat exchanger, the other part of the high-pressure liquid refrigerant exchanges heat and flows to the electronic expansion valve corresponding to the first inner machine for throttling and depressurization through the MS supercooling plate, the low-temperature low-pressure gas-liquid two-phase refrigerant after throttling and depressurization is evaporated into a low-temperature gaseous refrigerant by the first inner machine, the low-temperature gaseous refrigerant evaporated by the two evaporators flows back to the compressor after passing through the gas-liquid separator to be continuously compressed into the high-temperature high-pressure gaseous refrigerant and then flows to the condenser (the first inner machine), and the circulation operation is realized, and the main heating mode of the multi-connected air conditioning system is realized.

In the main heating operation process, after the compressor enters PI (Proportional Integral) control, frequent fluctuation of the outdoor heat exchanger between the condenser and the evaporator is easily caused due to slight change of external environment temperature or system state, and further the working state of the second internal machine is changed, so that the operation mode of the second internal machine needs to be detected in real time, the operation mode of the external machine is adjusted according to the operation mode of the second internal machine, the operation mode of the external machine can be adjusted to be a refrigeration mode, frequent fluctuation of the external machine between the condenser and the evaporator is avoided, and the system is stably operated.

After the operation mode of the outdoor unit is adjusted to the refrigeration mode, the multi-split air-conditioning system may operate in a pure refrigeration mode or a main refrigeration mode, so that switching of the multi-split air-conditioning system from the main heating mode to the pure refrigeration mode or from the main heating mode to the main refrigeration mode can be realized.

It should be noted that, in this embodiment, for the multi-split air conditioning system with the initial operation mode being the main heating operation mode or the main cooling operation mode, an ideal situation exists in the operation process of the multi-split air conditioning system, in which the expansion valve of the external unit is close to the set minimum value and the wind level of the external fan is at the lowest wind level, at this time, the external unit has a small function as an evaporator or a condenser, and the corresponding second internal unit and the first internal unit respectively serve as the respective condenser and evaporator to achieve a good heat recovery effect without adjusting the operation mode of the external unit, and the system can maintain a proper high-low pressure stable operation. Therefore, the control method of the multi-split air conditioning system in the embodiment of the invention aims at the situation that the system cannot maintain proper high and low pressure to stably operate after the system is actively adjusted within a certain time.

In summary, in the control method of the multi-split air conditioning system according to the embodiment of the present invention, when an outdoor heat exchanger of the multi-split air conditioning system is monolithic (i.e., the system may only be used as a condenser or an evaporator), and the system may operate in a main heating mode, or may operate in a main cooling mode, current operating states of N internal machines in the multi-split air conditioning system are detected, and if only one of the N internal machines operates in a cooling mode and one of the N internal machines operates in a heating mode, the current operating mode of an external machine is detected, and then when the external machine is currently in the cooling mode, that is, the system operates in the main cooling mode, the operating mode of the external machine is adjusted according to the operating mode of a first internal machine operating in the cooling mode, so as to avoid frequent fluctuation of the external machine between the condenser and the evaporator due to a change in an external environment temperature or a system state; when the outdoor unit is in the heating mode currently, namely the system operates in the main heating mode, the operation mode of the outdoor unit is adjusted according to the operation mode of the second indoor unit operating in the heating mode, so that frequent fluctuation of the outdoor unit between the condenser and the evaporator caused by external environment temperature or system state change is avoided.

Therefore, the control method adjusts the operation mode of the outer unit according to the current operation modes of the N inner units and the current operation mode of the outer unit of the multi-split air conditioning system, and can avoid the problem of frequent fluctuation of the operation mode of the system, so that the system is in a long-term stable operation state to the maximum extent, the reliability of the operation of the system is ensured, and the comfort of users is improved.

In an embodiment of the present invention, the adjusting the operation mode of the outer unit according to the operation mode of the first inner unit in the step S3 may include: if the first internal machine is changed from the refrigerating operation mode to the non-refrigerating operation mode, the external machine is adjusted from the refrigerating mode to the heating mode; wherein, the non-refrigeration operation mode comprises any one of the following modes: shutdown, shutdown to temperature, forced shutdown to prevent freezing and heating mode.

Specifically, in the process that the multi-split air conditioning system operates in the main cooling mode, if the first internal machine operating in the cooling mode is changed from the cooling operation mode to any one of shutdown, temperature-reaching shutdown, anti-freezing forced shutdown and heating mode, it indicates that the refrigeration system is in a state of only a condenser but not an evaporator at the moment, and a compressor of the refrigeration system without the evaporator cannot establish a stable high-low pressure difference to maintain the reliable operation of the system.

That is, if the first internal machine operating in the cooling mode is changed from the cooling mode to any one of shutdown, warm-up shutdown and freezing-prevention forced shutdown, the switched multi-online air conditioning system operates in the pure heating mode (the second internal machine is used as a condenser, and the external machine is used as an evaporator); if the first internal machine which operates in the cooling mode is changed from the cooling operation mode to the heating mode, the switched multi-online air conditioning system also operates in the pure heating mode (the first internal machine and the second internal machine are used as condensers, and the external machine is used as an evaporator).

Further, according to the operation mode of the first inner unit, adjusting the operation mode of the outer unit includes: if the first internal machine maintains the cooling operation mode, judging whether the current operation state of the multi-split air-conditioning system meets the following first conditions: the time difference between the previous operation mode adjustment time and the current time of the outdoor unit is greater than a first time threshold a, the absolute value abs (Tc-Tc1) of the difference between the saturated condensation temperature Tc corresponding to the current condensation pressure and the saturated condensation temperature Tc1 corresponding to the condensation pressure at the previous time is smaller than a first temperature threshold T1, and the duration of the lowest wind shield maintaining time of the wind shield of the outdoor unit is greater than a second time threshold b; if the current operation state of the multi-split air-conditioning system meets each first condition, judging whether the duration that the saturated condensing temperature Tc corresponding to the current condensing pressure of the multi-split air-conditioning system is smaller than a second temperature threshold T2 is larger than a third time threshold c; and if so, adjusting the outdoor unit from the cooling mode to the heating mode.

The previous operation mode adjustment time of the external unit refers to the time of switching between the cooling mode and the heating mode of the external unit last time.

Specifically, in the process that the multi-split air conditioning system operates in the main cooling mode, if the first internal machine operating in the cooling mode is not changed from the cooling mode to any one of the shutdown mode, the temperature-reaching shutdown mode, the anti-freezing forced shutdown mode and the heating mode, but maintains the cooling operation mode, the time difference between the previous operation mode adjustment time of the external machine and the current time, the absolute value abs (Tc-Tc1) of the difference between the saturated condensing temperature Tc corresponding to the current condensing pressure and the saturated condensing temperature Tc1 corresponding to the condensing pressure at the previous time, which are detected once every first preset time, and the duration of the lowest wind level maintained by the wind level of the external machine can be obtained, and whether the current operation state of the multi-split air conditioning system meets the following first conditions (preliminary conditions) is further determined: the time difference between the previous operation mode adjustment time of the outdoor unit and the current time is greater than a first time threshold a, the absolute value abs (Tc-Tc1) of the difference between the saturated condensation temperature Tc corresponding to the current condensation pressure and the saturated condensation temperature Tc1 corresponding to the condensation pressure at the previous time is less than a first temperature threshold T1, the duration of the lowest wind shield of the outdoor unit is greater than a second time threshold b, if the first conditions are met, the current outdoor unit meets the preliminary condition of the operation mode adjustment, whether the current operation state of the multi-split air conditioning system meets the following first final condition is judged, namely whether the duration of the saturated condensation temperature Tc corresponding to the current condensation pressure being less than the second temperature threshold T2 is greater than a third time threshold c, if the saturated condensation temperature Tc corresponding to the current condensation pressure being less than the second temperature threshold T2 and the duration being greater than the third time threshold c, the method can be shown that when the current system meets the first ultimate condition of the operation mode switching of the outdoor unit, the outdoor unit is adjusted from the cooling mode to the heating mode.

In this example, if the current operating state of the multi-split air conditioning system does not satisfy the preliminary condition, it is described that the current external unit does not satisfy the preliminary condition for switching the operating mode, so that the external unit maintains the cooling mode to continue operating, and in the operating process, it can be further determined whether the external unit satisfies the preliminary condition for adjusting the operating mode to perform corresponding control.

That is, in this example, when the current operating state of the multi-split air conditioning system satisfies both the preliminary condition and the first final condition, the outdoor unit is adjusted from the cooling mode to the heating mode.

Further, after determining whether the saturated condensing temperature Tc corresponding to the current condensing pressure of the multi-split air conditioning system is less than the second temperature threshold T2 and the duration is greater than the third time threshold c, the method may further include: if not, judging whether the duration that the saturated condensing temperature Tc corresponding to the current condensing pressure of the multi-split air-conditioning system is smaller than the third temperature threshold T3 is larger than a fourth time threshold d, and whether the duration that the saturated evaporating temperature Te corresponding to the current evaporating pressure is smaller than the fourth temperature threshold T4 is larger than a fifth time threshold e, wherein the third temperature threshold T3 is larger than the second temperature threshold T2, and the third time threshold c is larger than the fourth time threshold d; and if so, adjusting the outdoor unit from the cooling mode to the heating mode.

Specifically, if the current system meets the preliminary condition of the operation mode adjustment of the outdoor unit, but does not meet the first final condition of the operation mode adjustment, it is determined whether the current operation state of the system meets the second final condition, that is, whether the duration that the saturated condensing temperature Tc corresponding to the current condensing pressure is smaller than the third temperature threshold T3 is greater than the fourth time threshold d, and whether the duration that the saturated evaporating temperature Te corresponding to the current evaporating pressure is smaller than the fourth temperature threshold T4 is greater than the fifth time threshold e, where T3 is greater than T2, and c is greater than d, and if so, the second final condition is met, which indicates that the current system meets the second final condition of the operation mode switching of the outdoor unit, the outdoor unit is adjusted from the cooling mode to the heating mode. Wherein, the second time threshold b, the fourth time threshold d and the fifth time threshold e may be the same.

That is, in this example, when the current operating state of the multi-split air conditioning system operating in the main cooling mode satisfies both the preliminary condition and the second final condition, the outdoor unit is adjusted from the cooling mode to the heating mode.

In this example, if the current operating state of the multi-split air conditioning system does not satisfy neither the first final condition nor the second final condition, it is described that the current external unit does not satisfy the condition for switching the operating mode, so that the external unit maintains the cooling mode to continue operating, and during the operating process, it may be further determined whether the external unit satisfies the preliminary condition for adjusting the operating mode, the first final condition, and the second final condition, so as to perform corresponding control.

The principle of adjusting the current operation mode of the external machine in this example is as follows: for a multi-split air conditioning system operating in a main cooling mode, only a first indoor unit and a second indoor unit in a cooling mode and a heating mode exist in N indoor units, particularly when the capacity of the first indoor unit is small, the heat exchange area of a total condenser is correspondingly large, when the electronic expansion valve of the outer machine is adjusted to be small and the wind gear of the outer fan is adjusted to be the lowest wind gear for a period of time, the condenser is still larger, so that the high pressure of the system is lower, the synchronous low pressure is also lower, namely, the state of the second final condition appears, at this time, if the system continues to maintain the main refrigeration state, the outlet air temperature of the second inner machine is lower, and at the same time, the outlet air temperature of the first inner machine is too low (even freezing-proof shutdown appears), which affects the comfort of users, and at this time, the system is difficult to maintain the stability of the cooling state, a system fluctuation state occurs, and the system is more stable by switching to the main heating mode. If the low pressure drops too low (such as the first indoor unit ambient temperature is high or the indoor unit wind level is high), but the high pressure drops too low, that is, the first end condition is satisfied, and then the main cooling and main heating mode is directly performed after the high pressure drops to the second temperature threshold T2 and continues for the third time threshold c.

Based on the above example, as shown in fig. 3, when only the first internal machine is in the cooling operation mode and the second internal machine is in the heating operation mode among the N internal machines of the multi-split air conditioning system, and the current operation mode of the external machine is the cooling mode, the operation mode of the external machine may be adjusted according to the following steps:

s301, if the first internal unit is changed from the cooling operation mode to the non-cooling operation mode, the external unit is adjusted from the cooling mode to the heating mode, wherein the non-cooling operation mode comprises any one of the following modes: shutdown, shutdown to temperature, anti-freezing forced shutdown and heating mode, if yes, executing step S306; if not, step S302 is performed.

And S302, judging whether the first internal machine maintains the cooling operation mode, and if so, executing the step S303.

S303, judging whether the current running state of the multi-split air conditioning system meets the following first conditions: the time difference between the previous operation mode adjustment time of the external machine and the current time is greater than a first time threshold a, the absolute value abs (Tc-Tc1) of the difference between the saturated condensation temperature Tc corresponding to the current condensation pressure and the saturated condensation temperature Tc1 corresponding to the condensation pressure at the previous time is less than a first temperature threshold T1, the duration of the lowest wind gear maintenance of the wind gear of the external machine is greater than a second time threshold b, and if yes, the step S304 is executed; if not, return to step S301.

S304, judging whether the duration that the saturated condensing temperature Tc corresponding to the current condensing pressure of the multi-split air conditioning system is smaller than a second temperature threshold T2 is larger than a third time threshold c, if so, executing a step S306; if not, step S305 is performed.

S305, judging whether the duration that the saturated condensing temperature Tc corresponding to the current condensing pressure of the multi-split air conditioning system is smaller than a third temperature threshold T3 is larger than a fourth time threshold d, and the duration that the saturated evaporating temperature Te corresponding to the current evaporating pressure is smaller than a fourth temperature threshold T4 is larger than a fifth time threshold e, if yes, executing a step S306; if not, return to step S301.

And S306, adjusting the outdoor unit from the cooling mode to the heating mode.

Therefore, when the first inner machine is in the cooling operation mode, the second inner machine is in the heating operation mode and the outer machine is in the cooling mode, the operation mode of the outer machine is adjusted according to the preliminary condition, the first final condition and the second final condition, and the problem that the operation mode of the outer machine fluctuates frequently can be solved.

In an embodiment of the present invention, the adjusting the operation mode of the outer unit according to the operation mode of the second inner unit in the step S4 may include: if the second indoor unit is changed from the heating operation mode to the non-heating operation mode, the outdoor unit is adjusted from the heating mode to the cooling mode; wherein, the non-heating operation mode comprises any one of the following modes: shutdown, temperature-reaching shutdown and refrigeration mode.

Specifically, in the process that the multi-split air conditioning system operates in the main heating mode, if the second indoor unit operating in the heating mode is changed from the heating mode to any one of the shutdown mode, the temperature-reaching shutdown mode and the refrigerating mode, it indicates that the heating system is in a state of only an evaporator but not a condenser at the moment, and a compressor of the refrigerating system without the condenser cannot establish a stable high-low pressure difference to maintain the reliable operation of the system.

That is, if the second inner unit operating in the heating mode is changed from the heating mode to one of shutdown and warm-up shutdown, the switched multi-split air conditioning system operates in the pure cooling mode (the first inner unit serves as an evaporator, and the outer unit serves as a condenser); if the second inner machine which operates in the heating mode is changed from the heating operation mode to the cooling mode, the switched multi-split air conditioning system also operates in the pure cooling mode (the first inner machine and the second inner machine are used as evaporators, and the outer machine is used as a condenser).

Further, according to the mode of operation of the second inner machine, adjusting the mode of operation of the outer machine includes: if the second internal machine maintains the heating operation mode, judging whether the current operation state of the multi-split air-conditioning system meets the following second conditions: the time difference between the previous operation mode adjustment time of the outdoor unit and the current time is larger than a first time threshold a, the absolute value abs (Te-Te1) of the difference between the saturated evaporation temperature Te corresponding to the current evaporation pressure and the saturated evaporation temperature Te1 corresponding to the evaporation pressure at the previous time is smaller than a fifth temperature threshold T5, and the duration of the lowest wind gear maintaining time of the wind gear of the outdoor unit is larger than a sixth time threshold f; if the current operating state of the multi-split air-conditioning system meets the second conditions, judging whether the current operating state of the multi-split air-conditioning system meets the following third conditions: whether the duration that the saturated condensing temperature Tc corresponding to the current condensing pressure is greater than the sixth temperature threshold T6 is greater than a seventh time threshold g, whether the duration that the saturated evaporating temperature Te corresponding to the current evaporating pressure is greater than the seventh temperature threshold T7 is greater than an eighth time threshold h, and whether the duration that the frequency of the compressor in the outdoor unit is less than the frequency threshold i is greater than a ninth time threshold i; and if the current operating state of the multi-split air-conditioning system meets the third conditions, adjusting the outdoor unit from the heating mode to the cooling mode.

The previous operation mode adjustment time of the outdoor unit refers to the time of switching between the heating mode and the cooling mode of the outdoor unit last time.

Specifically, in the process that the multi-split air-conditioning system operates in the main heating mode, if the second internal machine is not changed from the heating mode to any one of the shutdown mode, the temperature-reaching shutdown mode and the cooling mode, but maintains the heating operation mode, the absolute value abs (Te-Te1) of the difference between the previous operation mode adjustment time and the current time of the external machine, the difference between the saturated evaporating temperature Te corresponding to the current evaporating pressure and the saturated evaporating temperature Te1 corresponding to the evaporating pressure at the previous time, which are detected once every first preset time, and the duration of the lowest wind level maintained by the wind level of the external machine can be obtained, so as to determine whether the current operation state of the multi-split air-conditioning system meets the following second conditions (preliminary conditions): the time difference between the previous operation mode adjustment time and the current time of the outer machine is greater than a first time threshold a, the absolute value abs (Te-Te1) of the difference between the saturated evaporating temperature Te corresponding to the current evaporating pressure and the saturated evaporating temperature Te1 corresponding to the evaporating pressure at the previous time is less than a fifth temperature threshold T5, and the duration of the lowest wind shield maintenance of the wind shield of the outer machine is greater than a sixth time threshold f (namely, more than f minutes); if the second conditions are met, the current external unit meets the preliminary conditions of operation mode adjustment, whether the current operation state of the multi-split air-conditioning system meets the following third conditions (final conditions) is judged, namely whether the duration that the saturated condensing temperature Tc corresponding to the current condensing pressure is greater than a sixth temperature threshold T6 is greater than a seventh time threshold g, the duration that the saturated evaporating temperature Te corresponding to the current evaporating pressure is greater than a seventh temperature threshold T7 is greater than an eighth time threshold h, and the duration that the frequency of the compressor in the external unit is less than a frequency threshold is greater than a ninth time threshold i, if yes, the final conditions are met, the current system meets the final conditions of external unit operation mode switching, and the external unit is adjusted from the heating mode to the cooling mode. Wherein, the sixth time threshold f, the seventh time threshold g, the eighth time threshold h and the ninth time threshold i may be the same, and the fifth temperature threshold T5 and the first temperature threshold T1 may be the same.

That is, in this example, when the current operating state of the multi-split air conditioning system operating in the main heating mode satisfies both the initial condition and the final condition, the outdoor unit is adjusted from the heating mode to the cooling mode.

In this example, if the current operating state of the multi-split air-conditioning system does not satisfy the preliminary condition, or the current operating state satisfies the preliminary condition but does not satisfy the final condition, it is described that the current external unit does not satisfy the condition for switching the operating mode, so that the external unit maintains the heating mode to continue operating, and during the operating process, it may be further determined whether the external unit satisfies the preliminary condition and the final condition for adjusting the operating mode, so as to perform corresponding control.

The principle of adjusting the current operation mode of the external machine in this example is as follows: for a multi-split air conditioning system operating in a main heating mode, only a first indoor unit operating in a cooling mode and a second indoor unit operating in a heating mode exist in N indoor units, particularly when the capacity of the second indoor unit is smaller, the total heat exchange area of an evaporator is correspondingly too large, the heat exchange area of a condenser is too small, in order to reduce the evaporation capacity of the outdoor unit to the minimum, an electronic expansion valve of the outdoor unit is reduced, the wind gear of the outdoor unit is reduced, but the high pressure of the system is high when the condenser is smaller, so that the wind gear of the outdoor unit of the system maintains the lowest wind gear for a sixth time threshold f, the high pressure and the low pressure of the system are still high, when a certain value is reached, namely the time difference between the previous operation mode adjustment time of the outdoor unit and the current time is greater than a first time threshold a, and the absolute value abs (Te-Te1) of the saturated evaporation temperature Te corresponding to the current evaporation pressure and the saturated evaporation temperature Te1 corresponding to the evaporation pressure at the previous time is smaller than a fifth temperature threshold T5, at the moment, the system is difficult to continuously maintain the stability of the heating state, the system fluctuation state can occur, the system can be more stable by switching to the main refrigeration mode, and therefore the system realizes that the main heating mode is switched to the main refrigeration mode.

Based on the above example, as shown in fig. 4, when only the first internal machine is in the cooling operation mode and the second internal machine is in the heating operation mode among the N internal machines of the multi-split air conditioning system, and the current operation mode of the external machine is the heating mode, the operation mode of the external machine may be adjusted according to the following steps:

s401, judging whether the second internal machine is changed from a heating operation mode to a non-heating operation mode or not; wherein, the non-heating operation mode comprises any one of the following modes: shutdown, reaching temperature shutdown and refrigeration mode, if yes, executing step S405; if not, step S402 is performed.

And S402, whether the second indoor unit maintains the heating operation mode or not is judged, and if so, the step S403 is executed.

S403, judging whether the current operating state of the multi-split air conditioning system meets the following second conditions: the time difference between the previous operation mode adjustment time of the outdoor unit and the current time is greater than a first time threshold a, the absolute value abs (Te-Te1) of the difference between the saturated evaporating temperature Te corresponding to the current evaporating pressure and the saturated evaporating temperature Te1 corresponding to the evaporating pressure at the previous time is less than a fifth temperature threshold T5, the duration of the lowest wind gear maintained by the wind gear of the outdoor unit is greater than a sixth time threshold f, and if yes, the step S404 is executed; if not, return to step S401.

S404, judging whether the current operating state of the multi-split air conditioning system meets the following third conditions: whether the duration that the saturated condensing temperature Tc corresponding to the current condensing pressure is greater than the sixth temperature threshold T6 is greater than the seventh time threshold g, whether the duration that the saturated evaporating temperature Te corresponding to the current evaporating pressure is greater than the seventh temperature threshold T7 is greater than the eighth time threshold h, and whether the duration that the frequency of the compressor in the outdoor unit is less than the frequency threshold i is greater than the ninth time threshold i, if yes, step S405 is executed; if not, return to step S401.

And S405, adjusting the outdoor unit from the heating mode to the cooling mode.

Therefore, when the first inner machine is in the cooling operation mode, the second inner machine is in the heating operation mode and the outer machine is in the heating mode, the operation mode of the outer machine is adjusted according to the initial condition and the final condition, and the problem that the operation mode of the outer machine fluctuates frequently can be solved.

In one example of the present invention, the control method of the multi-split air conditioning system may further include: acquiring a starting instruction, wherein the starting instruction comprises an instruction for instructing a first indoor unit to start a refrigerating operation mode and an instruction for instructing a second indoor unit to start a heating operation mode; and determining the starting operation mode of the outer machine according to the starting operation mode and the capacity of the first inner machine and the starting operation mode and the capacity of the second inner machine.

Specifically, when the multi-split air conditioning system needs to be started, a starting instruction can be sent to the system, so that the first internal machine starts a cooling operation mode and the second internal machine starts a heating operation mode, and further the starting operation mode of the external machine is determined according to the starting operation modes and the capacities of the first internal machine and the second internal machine. Specifically, the capacities of the first inner unit and the second inner unit can be compared to obtain the inner unit with the smaller capacity, and then the starting operation heat exchanger state of the outer unit is determined to be the same as that of the inner unit with the smaller capacity, so that the multi-split air-conditioning system is started.

For example, if the capacity of the first inner unit that starts the cooling operation mode is large, and the capacity of the second inner unit that starts the heating operation mode is small, that is, the capacity of the evaporator is large, and the capacity of the condenser is small, the start operation mode of the system that starts the system in a relatively stable state is the cooling mode, even if the outer unit is used as the condenser to operate the multi-split air conditioning system in the main cooling mode, the operation mode of the outer unit is adjusted according to the operation mode of the first inner unit and the change of the system operation state during the operation (that is, the above steps S301 to S306), so that the system operates stably and reliably.

For another example, if the capacity of the first internal machine that starts the cooling operation mode is small, and the capacity of the second internal machine that starts the heating operation mode is large, that is, the capacity of the evaporator is small, and the capacity of the condenser is large, the starting operation mode of the system that starts relatively stably is the starting operation mode of the external machine, that is, the external machine is used as the evaporator, so that the multi-split air-conditioning system operates in the main heating mode, and during the operation process, the operation mode of the external machine is adjusted according to the operation mode of the second internal machine and the change of the system operation state (that is, the steps S401 to S405), so that the system operates stably and reliably.

That is to say, in this example, when the start-up operation modes of the first internal machine and the second internal machine are different, and the capacities are different (even the difference is large), the state of the start-up operation heat exchanger of the external machine can be determined according to the start-up operation mode of the internal machine with the smaller capacity. When the capacity difference between the first inner machine and the second inner machine is large, if the state of the outer machine heat exchanger is consistent with the mode of the heat exchanger with the small capacity of the inner machine, the system is usually in a stable state and does not fluctuate. When the capacity difference between the first internal machine and the second internal machine is small, the system is usually in an unstable state, and the system can obtain a good control effect by adopting the control method provided by the embodiment of the invention.

In summary, the control method of the multi-split air conditioning system according to the embodiment of the present invention adjusts the operation mode of the external unit according to the current operation modes of the N internal units and the current operation mode of the external unit of the multi-split air conditioning system, so as to avoid the problem of frequent fluctuation of the operation mode of the system, so that the system is in a long-term stable operation state, the reliability of the operation of the system is ensured, and the comfort of the user is improved.

The present invention also provides a computer-readable storage medium having a computer program stored thereon, the computer program, when executed by a processor, implementing the control method of the multi-split air conditioning system described above.

The computer readable storage medium, when the computer program stored on the medium is executed by the processor, avoids the problem of frequent fluctuation of the system operation mode, thereby enabling the system to be in a long-term stable operation state, ensuring the reliability of the system operation and improving the comfort of users.

The invention also provides a control device of the multi-split air conditioning system, and fig. 5 is a structural block diagram of the control device of the multi-split air conditioning system according to an embodiment of the invention.

Referring to fig. 1, the multi-split air conditioning system includes an outdoor unit and N indoor units (four indoor units are shown in fig. 1, namely, a first indoor unit 1, a second indoor unit 2, a third indoor unit 3 and a fourth indoor unit 4), where N is an integer greater than or equal to 2, the outdoor unit is provided with an outdoor unit electronic expansion valve EXVA, an electronic expansion valve EXV1 is provided corresponding to the first indoor unit 1, an electronic expansion valve EXV2 is provided corresponding to the second indoor unit 2, an electronic expansion valve EXV3 is provided corresponding to the third indoor unit 3, and an electronic expansion valve EXV4 is provided corresponding to the fourth indoor unit 4.

As shown in fig. 5, the control device 100 of the multi-split air conditioning system includes: a first detection module 10, a second detection module 20, and a control module 30.

The first detection module 10 is configured to detect current operating states of N internal machines in the multi-split air conditioning system respectively; the second detection module 20 is configured to detect a current operation mode of the external unit if two internal units of the current N internal units are in a working state, the first internal unit is in a cooling operation mode, and the second internal unit is in a heating operation mode; the control module 30 is configured to adjust the operation mode of the external unit according to the operation mode of the first internal unit if the external unit is currently in the refrigeration mode; and the operation mode of the outdoor unit is adjusted according to the operation mode of the second indoor unit if the outdoor unit is in the heating mode currently.

Specifically, during the operation of the multi-split air conditioning system, first, the current operating states of N internal machines in the multi-split air conditioning system are respectively detected by the first detecting module 10, where the current operating states of the N internal machines may include: the air conditioner is not in a working state (shutdown state), in a working state and in a refrigerating operation mode, and in a working state and in a heating operation mode; then, when two internal machines of the current N internal machines are detected to be in working states, the first internal machine is in a cooling operation mode, and the second internal machine is in a heating operation mode, the current operation mode of the external machine is detected through the second detection module 20, and the detected result is sent to the control module 30; finally, the control module 30 adjusts the operation mode of the external unit according to the operation mode of the first internal unit when the external unit is currently in the cooling mode, and adjusts the operation mode of the external unit according to the operation mode of the second internal unit when the external unit is currently in the heating mode.

It should be noted that other specific embodiments of the control device of the multi-split air conditioning system may refer to the specific embodiments of the control method of the multi-split air conditioning system in the foregoing embodiments, and for avoiding redundancy, no further description is given here.

According to the control device of the multi-split air conditioning system, the operation mode of the outer unit is adjusted according to the current operation modes of the N inner units and the current operation mode of the outer unit of the multi-split air conditioning system, so that the problem of frequent fluctuation of the operation mode of the system can be avoided, the system is in a long-term stable operation state, the operation reliability of the system is ensured, and the comfort of users is improved.

Fig. 6 is a block diagram of a multi-split air conditioning system according to an embodiment of the present invention. As shown in fig. 6, the multi-split air conditioning system 1000 includes the control device 100 of the multi-split air conditioning system of the above-described embodiment.

According to the multi-split air conditioning system provided by the embodiment of the invention, the operation mode of the outer unit is adjusted according to the current operation modes of the N inner units and the current operation mode of the outer unit of the multi-split air conditioning system through the control device of the multi-split air conditioning system provided by the embodiment of the invention, so that the problem of frequent fluctuation of the operation mode of the system can be avoided, the system is in a long-term stable operation state, the operation reliability of the system is ensured, and the comfort and adaptability of a user are improved.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., 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 are not necessarily intended to 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. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing steps of a custom logic function or process, and alternate implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.

The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.

It should be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are well known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried out in the method of implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and the program, when executed, includes one or a combination of the steps of the method embodiments.

In addition, functional units in the embodiments of the present invention may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A control method of a multi-split air conditioning system is characterized in that the multi-split air conditioning system comprises an external unit and N internal units, wherein N is an integer greater than or equal to 2, and the control method comprises the following steps:

respectively detecting the current working states of N internal machines in the multi-split air conditioning system in real time;

if two internal machines in the N internal machines are in a working state, a first internal machine is in a refrigerating operation mode, and a second internal machine is in a heating operation mode, detecting the current operation mode of the external machine;

if the outdoor unit is in the refrigeration mode currently, adjusting the operation mode of the outdoor unit according to the operation mode of the first indoor unit;

if the outdoor unit is in the heating mode at present, adjusting the operation mode of the outdoor unit according to the operation mode of the second indoor unit;

the adjusting the operation mode of the outer machine according to the operation mode of the first inner machine comprises:

if the first internal machine is changed from a refrigeration operation mode to a non-refrigeration operation mode, adjusting the external machine from the refrigeration mode to a heating mode;

if the first internal machine maintains the refrigeration operation mode, judging whether the current operation state of the multi-split air conditioning system meets the following first conditions: the time difference between the previous operation mode adjusting time and the current time of the outdoor unit is larger than a first time threshold, the absolute value of the difference between the saturated condensing temperature corresponding to the current condensing pressure and the saturated condensing temperature corresponding to the condensing pressure at the previous time is smaller than a first temperature threshold, and the duration of the lowest wind shield of the outdoor unit is longer than a second time threshold;

if the current operation state of the multi-split air-conditioning system meets the first conditions, judging whether the duration of the saturated condensing temperature corresponding to the current condensing pressure of the multi-split air-conditioning system, which is smaller than a second temperature threshold, is larger than a third time threshold;

if so, adjusting the outdoor unit from a refrigeration mode to a heating mode;

if not, whether the duration that the saturated condensing temperature corresponding to the current condensing pressure of the multi-split air conditioner system is smaller than a third temperature threshold is larger than a fourth time threshold or not and whether the duration that the saturated evaporating temperature corresponding to the current evaporating pressure is smaller than a fourth temperature threshold is larger than a fifth time threshold or not are judged, wherein the third temperature threshold is larger than the second temperature threshold, and the third time threshold is larger than the fourth time threshold.

2. The control method of a multi-split air conditioning system as set forth in claim 1, wherein the non-cooling operation mode includes any one of the following modes: shutdown, shutdown to temperature, forced shutdown to prevent freezing and heating mode.

3. The control method according to any one of claims 1 to 2, wherein the adjusting the operation mode of the outer unit according to the operation mode of the second inner unit includes:

if the second internal machine is changed from the heating operation mode to the non-heating operation mode, adjusting the external machine from the heating mode to the cooling mode;

wherein, the non-heating operation mode comprises any one of the following modes: shutdown, temperature-reaching shutdown and refrigeration mode.

4. The control method according to claim 3, wherein the adjusting the operation mode of the outer unit according to the operation mode of the second inner unit includes:

if the second internal machine maintains the heating operation mode, judging whether the current operation state of the multi-split air conditioning system meets the following second conditions: the time difference between the previous operation mode adjustment moment and the current moment of the external machine is greater than a first time threshold, the absolute value of the difference between the saturated evaporation temperature corresponding to the current evaporation pressure and the saturated evaporation temperature corresponding to the evaporation pressure at the previous moment is smaller than a fifth temperature threshold, and the duration of the lowest wind shield of the external machine is greater than a sixth time threshold;

if the current operating state of the multi-split air-conditioning system meets the second conditions, judging whether the current operating state of the multi-split air-conditioning system meets the following third conditions or not:

whether the duration that the saturated condensing temperature corresponding to the current condensing pressure is greater than the sixth temperature threshold is greater than a seventh time threshold, whether the duration that the saturated evaporating temperature corresponding to the current evaporating pressure is greater than the seventh temperature threshold is greater than an eighth time threshold, and whether the duration that the frequency of the compressor in the outdoor unit is less than the frequency threshold is greater than a ninth time threshold;

and if the current operation state of the multi-split air-conditioning system meets the third conditions, adjusting the outdoor unit from a heating mode to a cooling mode.

5. The control method according to claim 4, further comprising:

acquiring a starting instruction, wherein the starting instruction comprises an instruction for instructing the first internal machine to start a cooling operation mode and an instruction for instructing the second internal machine to start a heating operation mode;

and determining the starting operation mode of the external machine according to the starting operation mode and the capacity of the first internal machine and the starting operation mode and the capacity of the second internal machine.

6. A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements a control method of a multi-split air conditioning system as set forth in any one of claims 1 to 5.

7. The utility model provides a controlling means of multi-split air conditioning system which characterized in that, multi-split air conditioning system includes an outer machine and N internal machines, and wherein, N is for being more than or equal to 2's integer, controlling means includes:

the first detection module is used for respectively detecting the current working states of N internal machines in the multi-split air conditioning system;

the second detection module is used for detecting the current operation mode of the external machine if two internal machines in the N internal machines are in working states, the first internal machine is in a refrigerating operation mode, and the second internal machine is in a heating operation mode;

the control module is used for adjusting the operation mode of the outer machine according to the operation mode of the first inner machine if the outer machine is in the refrigeration mode currently; and the controller is used for adjusting the operation mode of the outer machine according to the operation mode of the second inner machine if the outer machine is in the heating mode currently;

if the first internal machine maintains the refrigeration operation mode, judging whether the current operation state of the multi-split air conditioner system meets the following first conditions: the time difference between the previous operation mode adjustment time of the external unit and the current time is larger than a first time threshold, the absolute value of the difference between the saturated condensing temperature corresponding to the current condensing pressure and the saturated condensing temperature corresponding to the condensing pressure at the previous time is smaller than a first temperature threshold, and the duration of the lowest wind shield of the external unit is larger than a second time threshold;

if so, adjusting the outdoor unit from a refrigeration mode to a heating mode;

if not, judging whether the duration of the saturated condensing temperature corresponding to the current condensing pressure of the multi-split air-conditioning system, which is smaller than the third temperature threshold, is greater than a fourth time threshold and whether the duration of the saturated evaporating temperature corresponding to the current evaporating pressure, which is smaller than the fourth temperature threshold, is greater than a fifth time threshold, wherein the third temperature threshold is greater than the second temperature threshold and the third time threshold is greater than the fourth time threshold.

8. A multi-split air conditioning system, comprising the control device of the multi-split air conditioning system as set forth in claim 7.