CN109798644B - Control method and air conditioning system - Google Patents

Abstract

The invention discloses a control method and an air conditioning system. The air conditioning system comprises an outdoor unit, the outdoor unit comprises a plurality of external heat exchangers, and the control method comprises the following steps: determining the current opening quantity of the outer heat exchangers when the air conditioning system operates; acquiring the exhaust pressure and the exhaust superheat degree of an air conditioning system, or acquiring the exhaust superheat degree, the system temperature and the outdoor environment temperature; and adjusting the number of the opened outer heat exchangers according to the number, the exhaust pressure and the exhaust superheat degree of the current opened outer heat exchangers, or according to the number, the exhaust superheat degree, the system temperature and the outdoor environment temperature of the current opened outer heat exchangers. The running state of the outer heat exchanger is adjusted according to the actual requirement of the air conditioning system on the outer heat exchanger, so that the reliable and stable running of the air conditioning system can be ensured. Therefore, the air conditioning system can flexibly adapt to actual use requirements and simultaneously ensure the reliability of system operation.

Description

Control method and air conditioning system

Technical Field

The invention relates to the technical field of air conditioning equipment, in particular to a control method and an air conditioning system.

Background

In the related art, an air conditioning system is an apparatus for cooling and heating an indoor space, such as an inner space of a house, a restaurant, and an office. In order to effectively cool and heat an indoor space divided into several rooms, an air conditioning system has been developed to cool and heat each room independently at the same time. Specifically, a plurality of indoor units are connected to one outdoor unit, and the indoor units are installed in respective rooms. Each indoor unit operates in a cooling mode or in a heating mode and adjusts the air temperature of the indoor space. However, depending on the application of the air conditioning system, there are demands for low-temperature cooling, even ultra-low-temperature cooling, and heating and ultra-high-temperature heating, and these various demands place high demands on the cooling/heating load adjusting capability of the outdoor heat exchanger.

At present, a heat recovery system or a heat pump system of an air conditioning system adopts a design of two or more heat exchangers, but the requirements of the external heat exchangers are adjusted only according to outdoor environment temperature or starting capacity, so that the flexibility and the adaptability are poor, and the actual use requirements cannot be met.

Disclosure of Invention

The embodiment of the invention provides a control method and an air conditioning system.

A control method according to an embodiment of the present invention is used for an air conditioning system including an outdoor unit including a plurality of external heat exchangers, and includes:

determining the current opening number of the outer heat exchangers when the air conditioning system is in operation;

acquiring the exhaust pressure and the exhaust superheat degree of the air conditioning system, or acquiring the exhaust superheat degree, the system temperature and the outdoor environment temperature; and

and adjusting the number of the opened outer heat exchangers according to the number of the opened outer heat exchangers currently, the exhaust pressure and the exhaust superheat degree, or according to the number of the opened outer heat exchangers currently, the exhaust superheat degree, the system temperature and the outdoor environment temperature.

In the control method, the operation state of the outer heat exchanger is adjusted according to the actual requirement of the air conditioning system on the outer heat exchanger, so that the reliable and stable operation of the air conditioning system can be ensured. Therefore, the air conditioning system can flexibly adapt to actual use requirements and simultaneously ensure the reliability of system operation.

In some embodiments, the system temperature comprises a saturation temperature corresponding to a mid-evaporator temperature or return air pressure.

In some embodiments, the adjusting the number of the outer heat exchanger openings according to the number of the outer heat exchanger openings, the discharge pressure, and the discharge superheat, or according to the number of the outer heat exchanger openings, the discharge superheat, the system temperature, and the outdoor ambient temperature comprises: and when the air conditioning system operates in a cooling mode, adjusting the opening number of the outer heat exchanger according to the current opening number of the outer heat exchanger, the exhaust pressure and the exhaust superheat degree.

In some embodiments, the adjusting the number of the outer heat exchanger openings according to the number of the outer heat exchanger openings, the discharge pressure, and the discharge superheat when the air conditioning system is operating in the cooling mode comprises: when the exhaust pressure is greater than a first preset pressure and lasts for a first time period, increasing the number of the opened external heat exchangers; and when the exhaust pressure is less than or equal to a second preset pressure and lasts for a second time period, the exhaust superheat degree is less than or equal to a first preset value and lasts for a third time period, or the exhaust pressure is less than or equal to a third preset pressure and lasts for a fourth time period, the number of the opened external heat exchangers is reduced, the first preset pressure is greater than the second preset pressure, and the second preset pressure is greater than the third preset pressure.

In some embodiments, the adjusting the number of the outer heat exchanger openings according to the number of the outer heat exchanger openings, the discharge pressure, and the discharge superheat, or according to the number of the outer heat exchanger openings, the discharge superheat, the system temperature, and the outdoor ambient temperature comprises: and when the air conditioning system operates in a heating mode, adjusting the number of the opened external heat exchangers according to the number of the currently opened external heat exchangers, the exhaust superheat degree, the system temperature and the outdoor environment temperature.

In some embodiments, the adjusting the number of the external heat exchangers turned on according to the number of the external heat exchangers currently turned on, the system temperature, and the outdoor ambient temperature while the air conditioning system is operating in the heating mode includes: when the difference value between the outdoor environment temperature and the system temperature is greater than or equal to a second preset value, increasing the number of the opened external heat exchangers; and when the difference between the outdoor environment temperature and the system temperature is less than or equal to a third preset value and the exhaust superheat degree is less than or equal to a fourth preset value for a fifth time, reducing the number of the opened external heat exchangers, wherein the second preset value is greater than the third preset value.

In certain embodiments, the control method comprises: and after the air conditioning system runs for a preset time, adjusting the number of the opened external heat exchangers according to the number of the currently opened external heat exchangers, the exhaust pressure and the exhaust superheat degree, or according to the number of the currently opened external heat exchangers, the exhaust superheat degree, the system temperature and the outdoor environment temperature.

An air conditioning system of an embodiment of the present invention includes an outdoor unit and a control device, the outdoor unit includes a plurality of external heat exchangers, the number of the external heat exchangers is plural, and the control device is configured to determine, when the air conditioning system is operating, the number of currently opened external heat exchangers, and to acquire an exhaust pressure and an exhaust superheat degree of the air conditioning system, or acquire the exhaust superheat degree, a system temperature, and an outdoor ambient temperature, and to adjust the number of opened external heat exchangers according to the number of currently opened external heat exchangers, the exhaust pressure, and the exhaust superheat degree, or according to the number of currently opened external heat exchangers, the exhaust superheat degree, the system temperature, and the outdoor ambient temperature.

In the air conditioning system, the running state of the outer heat exchanger is adjusted according to the actual requirement of the air conditioning system on the outer heat exchanger, so that the reliable and stable running of the air conditioning system can be ensured. Therefore, the air conditioning system can flexibly adapt to actual use requirements and simultaneously ensure the reliability of system operation.

In some embodiments, the system temperature comprises a saturation temperature corresponding to a mid-evaporator temperature or return air pressure.

In some embodiments, the control means is configured to adjust the number of times the outer heat exchanger is turned on based on the number of times the outer heat exchanger is currently turned on, the discharge pressure, and the discharge superheat when the air conditioning system is operating in the cooling mode.

In certain embodiments, the control means is configured to increase the number of the external heat exchanger openings when the exhaust pressure is greater than a first preset pressure for a first period of time, and to decrease the number of the external heat exchanger openings when the exhaust pressure is less than or equal to a second preset pressure for a second period of time and the exhaust superheat is less than or equal to a first preset value for a third period of time, or the exhaust pressure is less than or equal to a third preset pressure for a fourth period of time, the first preset pressure being greater than the second preset pressure, the second preset pressure being greater than the third preset pressure.

In some embodiments, the control device is configured to adjust the number of the external heat exchangers that are turned on based on the number of the external heat exchangers that are currently turned on, the degree of superheat of the exhaust gas, the system temperature, and the outdoor ambient temperature when the air conditioning system is operating in the heating mode.

In some embodiments, the control device is configured to increase the number of the external heat exchanger that is turned on when the difference between the outdoor ambient temperature and the system temperature is greater than or equal to a second preset value, and to decrease the number of the external heat exchanger that is turned on when the difference between the outdoor ambient temperature and the system temperature is less than or equal to a third preset value and the degree of superheat of the exhaust gas is less than or equal to a fourth preset value for a fifth time duration, the second preset value being greater than the third preset value.

In some embodiments, the control device is configured to adjust the number of the external heat exchangers that are turned on according to the number of the external heat exchangers that are currently turned on, the discharge pressure, and the discharge superheat degree, or according to the number of the external heat exchangers that are currently turned on, the discharge superheat degree, the system temperature, and the outdoor ambient temperature after the air conditioning system is operated for a preset period of time.

An air conditioning system according to an embodiment of the present invention includes an outdoor unit including a plurality of external heat exchangers, a processor, and a memory, where a control program is stored in the memory, and the control program is executed by the processor to implement the control method according to any one of the above embodiments.

In the air conditioning system, the processor can execute the control program to adjust the running state of the outer heat exchanger according to the actual requirement of the air conditioning system on the outer heat exchanger, so that the reliable and stable running of the air conditioning system can be ensured. Therefore, the air conditioning system can flexibly adapt to actual use requirements and simultaneously ensure the reliability of system operation.

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

Drawings

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

fig. 1 is a block schematic diagram of an air conditioning system according to an embodiment of the present invention.

Fig. 2 is a schematic structural view of an air conditioning system according to an embodiment of the present invention.

Fig. 3 is a flowchart illustrating a control method according to an embodiment of the present invention.

Fig. 4 is another flow chart of the control method according to the embodiment of the present invention.

Fig. 5 is another flowchart illustrating a control method according to an embodiment of the present invention.

Fig. 6 is a further flowchart of the control method according to the embodiment of the present invention.

Fig. 7 is a further flowchart of the control method according to the embodiment of the present invention.

Fig. 8 is another block schematic diagram of an air conditioning system according to an embodiment of the present invention.

Description of the main element symbols:

theair conditioning system 10, theoutdoor unit 11, theouter heat exchanger 112, theindoor unit 12, theinner heat exchanger 122, thecontrol device 13, thecompressor 114, the four-way valve 14, thethrottling element 15, the low-pressure tank 16, theoil return device 17, thetemperature sensor 18, thepressure sensor 19, theprocessor 20 and thememory 21.

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 reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "left", "right", "inside", "outside", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. 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, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrally connected; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. Specific meanings of the above terms in the embodiments of the present invention can be understood by those of ordinary skill in the art according to specific situations.

Referring to fig. 1 and 2 together, anair conditioning system 10 according to an embodiment of the present invention includes anoutdoor unit 11, anindoor unit 12, and acontrol device 13, where theoutdoor unit 11 includes anexternal heat exchanger 112 and acompressor 114, and the number of theexternal heat exchangers 112 is plural. Theair conditioning system 10 can exchange heat with the outdoor environment through theouter heat exchanger 112, and can adjust the heat exchange amount of theouter heat exchanger 112 by adjusting the operation states of the plurality ofouter heat exchangers 112, so as to meet the cooling/heating requirements of theair conditioning system 10 under different operation states.

Specifically, in the example shown in fig. 1, the number of theoutdoor units 11 may be one, and oneoutdoor unit 11 includes twoexternal heat exchangers 112. Of course, in other examples, the number of theoutdoor units 11 may be multiple, and eachoutdoor unit 11 includes at least oneexternal heat exchanger 112, for example, oneoutdoor unit 11 includes oneexternal heat exchanger 112, or oneoutdoor unit 11 includes more than twoexternal heat exchangers 112. Theair conditioning system 10 may be a multi-split air conditioning system, and the number ofindoor units 12 may be one or more. In the illustrated embodiment, the number ofindoor units 12 is plural. In general, the number of theouter heat exchangers 112 is two or more regardless of the number of theoutdoor units 11.

In addition, theindoor unit 12 includes aninner heat exchanger 122, and theair conditioning system 10 can be operated in a cooling mode or a heating mode. When theair conditioning system 10 operates in the cooling mode, theouter heat exchanger 112 may be a condenser, theinner heat exchanger 122 may be an evaporator, and the refrigerant absorbs heat and evaporates in theinner heat exchanger 122 after being condensed and released by theouter heat exchanger 112, so that the indoor ambient temperature is reduced, and the cooling effect is achieved. When theair conditioning system 10 operates in the heating mode, theouter heat exchanger 112 may be an evaporator, theinner heat exchanger 122 may be a condenser, and the refrigerant is condensed by heat release of theinner heat exchanger 122 and then evaporated by heat absorption of theouter heat exchanger 112, so that the indoor ambient temperature is increased, and the heating effect is achieved.

For a multi-split air conditioning system having a plurality ofindoor units 12, the cooling mode of theair conditioning system 10 may refer to a pure cooling mode, and the heating mode of theair conditioning system 10 may refer to a pure heating mode. When theair conditioning system 10 operates in the pure cooling mode, the startedindoor units 12 all operate in the cooling mode; when theair conditioning system 10 operates in the pure heating mode, the activatedindoor units 12 all operate in the heating mode.

Specifically, in some embodiments, referring to fig. 2, theair conditioning system 10 includes a four-way valve 14 connecting theouter heat exchanger 112, theinner heat exchanger 122 and thecompressor 114, and theair conditioning system 10 can control the flow direction of the refrigerant by controlling the conduction state of the four-way valve 14, so as to meet the requirement of cooling or heating of theair conditioning system 10, that is, theair conditioning system 10 can control theair conditioning system 10 to operate in a cooling mode or a heating mode by controlling the conduction state of the four-way valve 14.

In certain embodiments, theair conditioning system 10 includes at least one throttlingelement 15 coupled to the plurality ofouter heat exchangers 112, and the operating conditions of the plurality ofouter heat exchangers 112 are determined based on the conduction state of the throttlingelement 15.

In particular, the number of throttlingelements 15 may be multiple, with each throttlingelement 15 being connected to oneouter heat exchanger 112 or to multipleouter heat exchangers 112. When the throttlingelement 15 is turned on, the correspondingouter heat exchanger 112 is turned on; when the throttlingelement 15 is closed, the correspondingouter heat exchanger 112 is closed. In the embodiment shown in fig. 2 the number of throttlingelements 15 is multiple, oneouter heat exchanger 112 being connected to each throttlingelement 15.

In one example, the throttlingelement 15 may be an electronic expansion valve, and the electronic expansion valve may adjust the opening of the valve according to the refrigerant pressure, so that theair conditioning system 10 maintains a certain pressure difference, and stabilizes the refrigerant pressure flowing through the evaporator, which is beneficial for theair conditioning system 10 to achieve a corresponding cooling/heating effect.

In certain embodiments, theair conditioning system 10 includes alow pressure tank 16 connecting theouter heat exchanger 112, theinner heat exchanger 122, and thecompressor 114, and anoil return 17 connecting thecompressor 114.

The low-pressure tank 16 is beneficial to ensuring stable return pressure of theair conditioning system 10, and can store liquid refrigerant, so as to prevent the liquid refrigerant from impacting thecompressor 114, thereby increasing reliability of theair conditioning system 10. Theoil return device 17 is used for separating the lubricating oil discharged from thecompressor 114 along with the refrigerant gas and providing the separated lubricating oil to thecompressor 114, so as to prevent thecompressor 114 from being damaged due to oil shortage.

Theair conditioning system 10 according to the embodiment of the present invention may control the state of theouter heat exchanger 112 by the control method according to the embodiment of the present invention, that is, the control method according to the embodiment of the present invention may be applied to theair conditioning system 10 according to the embodiment of the present invention.

Specifically, the control method of theair conditioning system 10 will be described below when theair conditioning system 10 operates in the cooling only mode.

Referring to fig. 3, in some embodiments, the control method includes:

step S1, determining the current number of theexternal heat exchangers 112 that are turned on when theair conditioning system 10 is operating in the pure cooling mode;

step S2, acquiring an exhaust pressure Pdis and an exhaust superheat Tdsh of theair conditioning system 10; and

in step S3, the number of theouter heat exchangers 112 that are opened is adjusted according to the number of theouter heat exchangers 112 that are currently opened, the exhaust pressure Pdis, and the exhaust superheat Tdsh.

With regard to theair conditioning system 10, when theair conditioning system 10 operates in the pure cooling mode, steps S1, S2, and S3 may be implemented by thecontrol device 13, that is, thecontrol device 13 may be configured to determine the number of currently openedexternal heat exchangers 112 when theair conditioning system 10 operates, and to obtain the discharge pressure Pdis and the discharge superheat Tdsh of theair conditioning system 10, and to adjust the number of currently openedexternal heat exchangers 112 according to the number of currently openedexternal heat exchangers 112, the discharge pressure Pdis, and the discharge superheat Tdsh.

In theair conditioning system 10 and the control method, the operation state of theouter heat exchanger 112 is controlled according to the actual requirement of theair conditioning system 10 on theouter heat exchanger 112, so that the reliable and stable operation of theair conditioning system 10 can be ensured. Thus, theair conditioning system 10 can flexibly adapt to actual use requirements while ensuring the reliability of system operation.

Specifically, theair conditioning system 10 includes atemperature sensor 18 and apressure sensor 19, and theair conditioning system 10 may acquire a discharge pressure Pdis of theair conditioning system 10 through thepressure sensor 19 disposed at a discharge port of thecompressor 114 and acquire a discharge temperature of theair conditioning system 10 through thetemperature sensor 18 disposed at the discharge port of thecompressor 114. The exhaust superheat degree Tdsh of theair conditioning system 10 is obtained according to the exhaust temperature and the exhaust pressure Pdis, that is, the exhaust superheat degree Tdsh is equal to a difference between the exhaust temperature and a saturation temperature corresponding to the exhaust pressure Pdis.

Specifically, when theair conditioning system 10 is turned on, or after defrosting and oil returning of theair conditioning system 10 are finished, theair conditioning system 10 may turn on the pure cooling mode, and at this time, theair conditioning system 10 may determine the number of theouter heat exchangers 112 to be turned on according to the system state parameters, and control the corresponding throttlingelement 15 to be turned on so as to turn on the correspondingouter heat exchangers 112.

Referring to fig. 4, in some embodiments, step S3 includes:

in step S32, when the exhaust pressure Pdis is greater than the first preset pressure theta₁And continues for a first duration α 1, increasing the number ofexternal heat exchangers 112 turned on; and

in step S34, when the exhaust pressure Pdis is less than or equal to the second preset pressure theta₂And the second time length alpha 2 is continued, and the exhaust superheat degree Tdsh is less than or equal to a first preset value

And continues for a third time period alpha 3, or the exhaust pressure Pdis is less than or equal to a third preset pressure theta₃And continues for a fourth duration a 4, the number of theouter heat exchangers 112 that are turned on is reduced.

For theair conditioning system 10, steps S32 and S34 may be implemented by thecontrol device 13, that is, thecontrol device 13 may be configured to control the exhaust pressure Pdis to be greater than the first preset pressure θ₁And for a first duration α 1, increasing the number of theexternal heat exchanger 112 being turned on, and for a discharge pressure Pdis less than or equal to a second preset pressure θ₂The exhaust superheat degree Tdsh is less than or equal to a first preset value

And continues for a third time period alpha 3, or the exhaust pressure Pdis is less than or equal to a third preset pressure theta₃And continues for a fourth duration a 4, the number of theouter heat exchangers 112 that are turned on is reduced.

Wherein the first preset pressure theta₁Greater than a second predetermined pressure theta₂Second predetermined pressure θ₂Greater than a third predetermined pressure theta₃。

When theair conditioning system 10 operates in the pure cooling mode, if the heat dissipation amount of theoutdoor unit 11 is too large, that is, the heat exchange amount of theexternal heat exchanger 112 is too large, the discharge pressure Pdis of theair conditioning system 10 may be small, and the cooling capacity of theair conditioning system 10 may be affected. If the heat dissipation amount of theoutdoor unit 11 is too small and the heat exchange amount of theexternal heat exchanger 112 is too small, the discharge pressure Pdis of theair conditioning system 10 may be large, which may also affect the cooling capability of theair conditioning system 10. As such, the heat exchange amount of theouter heat exchanger 112 may be determined by detecting the exhaust pressure Pdis of theair conditioning system 10 and according to the exhaust pressure Pdis of theair conditioning system 10.

Specifically, thecontrol device 13 may control the exhaust pressure Pdis to be greater than the first preset pressure θ₁The exhaust pressure Pdis obtained by time counting is larger than the first preset pressure theta₁Duration t 1; thecontrol device 13 may control the exhaust pressure Pdis to be less than or equal to the second preset pressure θ₂The exhaust pressure Pdis obtained by time counting is less than or equal to a second preset pressure theta₂Duration t 2; thecontrol device 13 is used for controlling the superheat degree Tdsh of the exhaust gas to be less than or equal to a first preset value

The exhaust superheat degree Tdsh obtained by time counting is less than or equal to a first preset value

Duration t 3; thecontrol device 13 may control the exhaust pressure Pdis to be less than or equal to the third preset pressure θ₃The exhaust pressure Pdis obtained by time counting is less than or equal to a third preset pressure theta₃Time duration t 4.

Wherein in the rowThe air pressure Pdis is greater than the first preset pressure theta₁Meanwhile, the exhaust pressure Pdis is too large, and at this time, if t1 reaches the first time length α 1, the number of the openedexternal heat exchanger 112 may be increased, so as to increase the heat exchange amount of theexternal heat exchanger 112, thereby increasing the heat exchange amount of theexternal heat exchanger 112.

The first time period α 1 may avoid frequent adjustment of theouter heat exchanger 112 due to fluctuation of the discharge pressure Pdis, which is beneficial to increase of reliability of theair conditioning system 10. In one example, the first time period α 1 may be 4 minutes.

Referring to fig. 5, in some embodiments, step S34 may first determine whether theair conditioning system 10 satisfies the condition that the discharge pressure Pdis is less than or equal to the second preset pressure θ₂And the second time length alpha 2 is continued, and the exhaust superheat degree Tdsh is less than or equal to a first preset value

And continuing the condition of the third duration alpha 3, if not, then judging whether the air-conditioning system 10 meets the condition that the exhaust pressure Pdis is less than or equal to the third preset pressure theta₃And continues for a fourth period of time α 4, and then thecontrol device 13 adjusts the number of theexternal heat exchanger 112 to be turned on according to the judgment result.

Of course, in other embodiments, step S32 may first determine whether theair conditioning system 10 satisfies the condition that the discharge pressure Pdis is less than or equal to the third preset pressure θ₃And continuing the condition of the fourth duration alpha 4, if not, then judging whether the air-conditioning system 10 meets the condition that the exhaust pressure Pdis is less than or equal to the second preset pressure theta₂And the second time length alpha 2 is continued, and the exhaust superheat degree Tdsh is less than or equal to a first preset value

And continues for a third period of time alpha 3, and then thecontrol device 13 adjusts the number of theexternal heat exchanger 112 to be turned on according to the judgment result.

When the exhaust pressure Pdis is less than or equal to a second preset pressure theta₂Meanwhile, the exhaust pressure Pdis is low, and at this time, whether the heat exchange amount of theouter heat exchanger 112 meets the requirement or not can be judged by combining the exhaust superheat Tdsh, and if the exhaust superheat Tdsh is less than or equal to the requirementFirst preset value

When the time t2 reaches the second time period α 2 and the time t3 reaches the third time period α 3, the number of the openedexternal heat exchangers 112 can be reduced, so that the heat exchange amount of theexternal heat exchangers 112 is reduced, and the normal refrigeration of theair conditioning system 10 is ensured.

Likewise, the second period α 2 and the third period α 3 may avoid frequent adjustment of theouter heat exchanger 112 due to fluctuations in the discharge pressure Pdis and/or the discharge superheat Tdsh, which may be beneficial to increase the reliability of theair conditioning system 10. Wherein the second time period α 2 and the third time period α 3 may be the same or different. In one example, the second period of time α 2 and the third period of time α 3 may be the same, with both the second period of time α 2 and the third period of time α 3 being 10 minutes.

Further, the exhaust pressure Pdis is less than or equal to a third preset pressure theta₃At this time, if the discharge pressure Pdis is too small, and at this time, if t4 reaches the fourth time length α 4, the number of the openedexternal heat exchangers 112 may be reduced, so as to reduce the heat exchange amount of theexternal heat exchangers 112, and theair conditioning system 10 may perform normal cooling.

Likewise, frequent adjustments of theouter heat exchanger 112 due to fluctuations in the discharge pressure Pdis may be avoided, which may be beneficial to increase the reliability of theair conditioning system 10. The fourth time period α 4 may or may not be the same as the second time period α 2 and/or the third time period α 3.

Likewise, the fourth time period α 4 may be the same as or different from the first time period α 1, the second time period α 2, and/or the third time period α 3. In one example, the fourth time length α 4 may be 10 minutes.

In some embodiments, theair conditioning system 10 operates in a pure cooling mode, and thecontrol device 13 may control the number of the openexternal heat exchangers 112 to remain unchanged when theair conditioning system 10 does not satisfy the above-described condition of increasing or decreasing the number of the openexternal heat exchangers 112. Theair conditioning system 10 may proceed to step S2 to obtain the exhaust pressure Pdis and the exhaust superheat Tdsh of theair conditioning system 10 again

It should be noted that the number of the openexternal heat exchangers 112 is at least one when theair conditioning system 10 is in operation, i.e., theexternal heat exchangers 112 are not all closed. Therefore, if the number of currently openedexternal heat exchangers 112 is one, and theair conditioning system 10 meets the condition of reducing the number of openedexternal heat exchangers 112, the number of openedexternal heat exchangers 112 may be kept unchanged, and theair conditioning system 10 may adjust the state of theair conditioning system 10 by the frequency of thecompressor 114, the opening degree of the throttlingelement 15, and/or the fan speed, so that theair conditioning system 10 may operate normally.

Accordingly, when theair conditioning system 10 is operated, the plurality ofouter heat exchangers 112 are all turned on, and theair conditioning system 10 satisfies the condition of increasing the number of the turned-onouter heat exchangers 112, the number of the turned-onouter heat exchangers 112 may be kept unchanged, and theair conditioning system 10 may adjust the state of theair conditioning system 10 by the frequency of thecompressor 114, the opening degree of the throttlingelement 15, and/or the rotational speed of the fan, etc., so that theair conditioning system 10 may be normally operated.

Of course, in other embodiments, if the number of theouter heat exchangers 112 is three or more, the first preset pressure θ is determined when theair conditioning system 10 adjusts the number of the opened outer heat exchangers 112₁A second predetermined pressure theta₂A third preset pressure theta₃And/or a first preset value

The change may be made based on the number of currently openouter heat exchangers 112.

That is, if it is determined that theair conditioning system 10 increases the number of theexternal heat exchangers 112 that are turned on, the first preset pressure θ when the number of theexternal heat exchangers 112 that are currently turned on is one₁May be equal to the first preset pressure theta when the number of currently openedouter heat exchangers 112 is two₁Different. If it is determined that theair conditioning system 10 decreases the number of theexternal heat exchangers 112 being turned on, the second preset pressure θ when the number of theexternal heat exchangers 112 being turned on is three is determined₂And a second preset pressure theta which is equal to the number of the currently openedouter heat exchanger 112 being two₂Different; the third preset pressure theta at which theouter heat exchanger 112 is currently opened in three₃And a third preset pressure theta which is equal to the number of the currently openedouter heat exchanger 112 being two₃Different; the number of currently openouter heat exchangers 112 is threeFirst preset value of hour

May be the first preset value corresponding to the number of currently-turned-onouter heat exchangers 112 being two

Different.

In some embodiments, a control method comprises: after theair conditioning system 10 operates in the pure cooling mode for a preset period of time, the number of the openedexternal heat exchangers 112 is adjusted according to the number of currently openedexternal heat exchangers 112, the discharge pressure Pdis, and the discharge superheat Tdsh.

For theair conditioning system 10, thecontrol device 13 may be configured to adjust the number of the openedouter heat exchangers 112 according to the number of the currently openedouter heat exchangers 112, the discharge pressure Pdis, and the discharge superheat Tdsh after theair conditioning system 10 operates in the pure cooling mode for a preset period of time.

Therefore, the preset time length can be enough time to stabilize the exhaust pressure Pdis and the exhaust superheat Tdsh after theair conditioning system 10 operates in the pure cooling mode, and the state of theouter heat exchanger 112 can be accurately controlled and adjusted according to the exhaust pressure Pdis and the exhaust superheat Tdsh.

Specifically, in one example, after theair conditioning system 10 is turned on in the pure cooling mode and operated for a first preset period of time, the number of theouter heat exchangers 112 that are turned on is adjusted according to the number of theouter heat exchangers 112 that are currently turned on, the discharge pressure Pdis, and the discharge superheat Tdsh. The pure refrigeration mode of theair conditioning system 10 may be the pure refrigeration mode of theair conditioning system 10 being turned on from the off state, or the pure refrigeration mode of theair conditioning system 10 being turned on after defrosting or oil returning is finished.

In another example, each time the time interval for adjusting the number of theexternal heat exchangers 112 turned on is not less than the second preset time period, that is, after theair conditioning system 10 adjusts the number of theexternal heat exchangers 112 turned on and operates in the pure cooling mode for the second preset time period, the number of theexternal heat exchangers 112 turned on is adjusted again according to the number of theexternal heat exchangers 112 currently turned on, the discharge pressure Pdis and the discharge superheat Tdsh.

Further, in one example, the first predetermined period of time may be 15 minutes. The second preset time period may be 5 minutes. Of course, in other examples, the first preset duration and the second preset duration may not be limited to the above discussed embodiments, but may be flexibly configured according to actual needs, and are not specifically limited herein.

A control method of theair conditioning system 10 will be described below when theair conditioning system 10 operates in the pure heating mode.

Referring to fig. 6, in some embodiments, the control method includes:

step S1', when theair conditioning system 10 is operating in the pure heating mode, determining the number of currently openexternal heat exchangers 112;

step S2', obtaining the exhaust superheat Tdsh, the system temperature Te, and the outdoor ambient temperature To of theair conditioning system 10; and

in step S3', the number of theouter heat exchangers 112 that are turned on is adjusted based on the number of theouter heat exchangers 112 that are currently turned on, the degree of superheat Tdsh of the exhaust gas, the system temperature Te, and the outdoor ambient temperature To.

For theair conditioning system 10, step S1 ', step S2 ' and step S3 ' may be implemented by thecontrol device 13, that is, thecontrol device 13 may be configured To determine the number of currently openedexternal heat exchangers 112 when theair conditioning system 10 is operating, and To obtain the exhaust superheat Tdsh, the system temperature Te and the outdoor ambient temperature To of theair conditioning system 10, and To adjust the number of openedexternal heat exchangers 112 according To the number of currently openedexternal heat exchangers 112, the exhaust superheat Tdsh, the system temperature Te and the outdoor ambient temperature To.

In theair conditioning system 10 and the control method, the operation state of theouter heat exchanger 112 is adjusted according to the actual requirement of theair conditioning system 10 on theouter heat exchanger 112, so that the reliable and stable operation of theair conditioning system 10 can be ensured. Thus, theair conditioning system 10 can flexibly adapt to actual use requirements while ensuring the reliability of system operation.

In some embodiments, the system temperature Te includes a refrigerant temperature in a middle portion of the evaporator or a saturation temperature corresponding to a return air pressure of theair conditioning system 10.

Specifically, theair conditioning system 10 may detect the outdoor ambient temperature To by thetemperature sensor 18 disposed in theoutdoor unit 11, and detect the refrigerant temperature in the middle of the evaporator by thetemperature sensor 18 disposed in the middle of theoutdoor heat exchanger 112 or detect the return air pressure by thepressure sensor 19 disposed at the return air port of thecompressor 114 and obtain the saturation temperature corresponding To the return air pressure. The saturation temperature corresponding to the return air pressure refers to the temperature of the refrigerant when the liquid refrigerant and the gaseous refrigerant reach dynamic balance under the return air pressure.

Referring to fig. 7, in some embodiments, step S3' includes:

step S32', when the difference between the outdoor environment temperature To and the system temperature Te is greater than or equal To the second preset value

While, the number ofexternal heat exchangers 112 turned on is increased; and

step S34', when the difference between the outdoor environment temperature To and the system temperature Te is less than or equal To the third preset value

The exhaust superheat degree Tdsh is less than or equal to a fourth preset value

And for a fifth duration a 5, the number of theouter heat exchangers 112 that are turned on is reduced.

For theair conditioning system 10, steps S32 'and S34' may be implemented by thecontrol device 13, that is, thecontrol device 13 may be configured To set the difference between the outdoor ambient temperature To and the system temperature Te To be greater than or equal To the second preset value

While, the number of the turn-on of theouter heat exchanger 112 is increased, and the difference between the outdoor ambient temperature To and the system temperature Te is less than or equal To the third preset value

The exhaust superheat degree Tdsh is less than or equal to a fourth preset value

And for a fifth duration a 5, the number of theouter heat exchangers 112 that are turned on is reduced.

Wherein the second preset value

Greater than a third predetermined value

Specifically, thecontrol device 13 may be configured to control the superheat degree Tdsh of the exhaust gas to be less than or equal to a fourth preset value

The exhaust superheat degree Tdsh obtained by time counting is less than or equal to a fourth preset value

Time duration t 5.

Theair conditioning system 10 operates in a pure heating mode, and the difference between the outdoor ambient temperature To and the system temperature Te is greater than or equal To a fourth preset value

At this time, the heat exchange amount of theouter heat exchanger 112 is small, and at this time, the number of the openedouter heat exchangers 112 may be increased, thereby increasing the heat exchange amount of theouter heat exchangers 112.

The difference between the outdoor ambient temperature To and the system temperature Te is less than or equal To a third preset value

And the exhaust superheat degree Tdsh of theair conditioning system 10 is less than or equal to a fourth preset value

Meanwhile, the discharge superheat Tdsh of theair conditioning system 10 is small, the difference between the outdoor ambient temperature To and the system temperature Te is small, and the heat dissipation amount of theoutdoor unit 11 is large, that is, the heat exchange amount of theouter heat exchanger 112 is large, which is whyIf t5 reaches the fifth duration α 5, the number ofouter heat exchangers 112 may be reduced.

The fifth time period α 5 may avoid frequent adjustment of theouter heat exchanger 112 due to fluctuation of the exhaust superheat Tdsh, which is beneficial to increasing the reliability of theair conditioning system 10. Further, the fifth time period α 5 is the same as or different from the first time period α 1, the second time period α 2, the third time period α 3, and/or the fourth time period α 4. In one example, the fifth time period α 5 may be 5 minutes.

In some embodiments, thecontrol device 13 may control the number of theexternal heat exchangers 122 to be turned on to remain the same when theair conditioning system 10 is operating in the pure heating mode and theair conditioning system 10 does not satisfy the above-mentioned condition of increasing or decreasing the number of theexternal heat exchangers 112 to be turned on. Theair conditioning system 10 may proceed To step S2' To again obtain the degree of superheat Tdsh of the exhaust air of theair conditioning system 10, the system temperature Te, and the outdoor ambient temperature To.

It should be noted that the number of the openexternal heat exchangers 112 is at least one when theair conditioning system 10 is in operation, i.e., theexternal heat exchangers 112 are not all closed. Therefore, if the number of currently openedexternal heat exchangers 112 is one, and theair conditioning system 10 meets the condition of reducing the number of openedexternal heat exchangers 112, the number of openedexternal heat exchangers 112 may be kept unchanged, and theair conditioning system 10 may adjust the state of theair conditioning system 10 by the frequency of thecompressor 114, the opening degree of the throttlingelement 15, and/or the fan speed, so that theair conditioning system 10 may operate normally.

Accordingly, when theair conditioning system 10 is operated, the plurality ofouter heat exchangers 112 are all turned on, and theair conditioning system 10 satisfies the condition of increasing the number of the turned-onouter heat exchangers 112, the number of the turned-onouter heat exchangers 112 may be kept unchanged, and theair conditioning system 10 may adjust the state of theair conditioning system 10 by the frequency of thecompressor 114, the opening degree of the throttlingelement 15, and/or the rotational speed of the fan, etc., so that theair conditioning system 10 may be normally operated.

Of course, in other embodiments, if the number of theouter heat exchangers 112 is three or more, the second preset value is determined when theair conditioning system 10 adjusts the number of the openedouter heat exchangers 112

Third preset value

And/or a fourth preset value

The change may be made based on the number of currently openouter heat exchangers 112.

That is, if it is determined that theair conditioning system 10 increases the number of theexternal heat exchangers 112 that are turned on, the second preset value when the number of theexternal heat exchangers 112 that are turned on is one is determined

A second preset value which may be equal to the number of currently-openedouter heat exchangers 112 of two

Different. If it is determined that theair conditioning system 10 decreases the number of theexternal heat exchangers 112 that are turned on, the current number of theexternal heat exchangers 112 that are turned on is the third preset value when three

A third preset value which may be equal to two times the number of currently openouter heat exchangers 112

Different; a fourth preset value when the number of currently-openedexternal heat exchangers 112 is three

A fourth preset value which may be equal to the number of currently-turned-onouter heat exchangers 112 of two

Different.

In some embodiments, a control method comprises: after theair conditioning system 10 operates in the pure heating mode for a preset time period, the number of the openedexternal heat exchangers 112 is adjusted according To the number of the currently openedexternal heat exchangers 112, the exhaust superheat degree Tdsh, the system temperature Te, and the outdoor ambient temperature To.

For theair conditioning system 10, thecontrol device 13 may be configured To adjust the number of the openedexternal heat exchangers 112 according To the number of the currently openedexternal heat exchangers 112, the degree of superheat Tdsh of exhaust gas, the system temperature Te, and the outdoor ambient temperature To after theair conditioning system 10 operates in the pure heating mode for a preset time period.

Accordingly, as in the cooling mode, the preset time duration may be enough time to stabilize the exhaust superheat Tdsh after theair conditioning system 10 operates in the pure heating mode, so as to ensure that the state of theouter heat exchanger 112 may be accurately controlled and adjusted according to the exhaust superheat Tdsh.

Specifically, in one example, after theair conditioning system 10 turns on the pure heating mode and operates for a third preset period of time, the number ofouter heat exchangers 112 turned on is adjusted based on the number ofouter heat exchangers 112 currently turned on, the degree of superheat Tdsh of the exhaust gas, the system temperature Te, and the outdoor ambient temperature To. The pure heating mode of theair conditioning system 10 may be the pure heating mode of theair conditioning system 10 being turned on from the off state, or the pure heating mode of theair conditioning system 10 being turned on after defrosting or oil returning is finished.

In another example, the time interval for adjusting the number of theexternal heat exchangers 112 turned on each time is not less than the second preset time period, that is, after theair conditioning system 10 adjusts the number of theexternal heat exchangers 112 turned on and operates in the pure heating mode for the fourth preset time period, the number of theexternal heat exchangers 112 turned on is adjusted according To the number of theexternal heat exchangers 112 turned on currently, the exhaust superheat Tdsh, the system temperature Te, and the outdoor ambient temperature To.

Further, in one example, the third predetermined period of time may be 15 minutes. The fourth preset time period may be 5 minutes. Of course, in other examples, the third preset duration and the fourth preset duration may not be limited to the above-discussed embodiments, but may be flexibly configured according to actual needs, and are not specifically limited herein.

Referring to fig. 8, anair conditioning system 10 according to an embodiment of the present invention includes anoutdoor unit 11, aprocessor 20 and amemory 21, where theoutdoor unit 11 includes a plurality ofexternal heat exchangers 112, thememory 21 stores a control program, and the control program is executed by theprocessor 20 to implement the control method according to any of the above embodiments.

In one example, the control program is executed by theprocessor 20 to implement the steps of:

step S1, determining the current number of theexternal heat exchangers 112 that are turned on when theair conditioning system 10 is operating in the pure cooling mode;

step S2, acquiring an exhaust pressure Pdis and an exhaust superheat Tdsh of theair conditioning system 10; and

in step S3, the number of theouter heat exchangers 112 that are opened is adjusted according to the number of theouter heat exchangers 112 that are currently opened, the exhaust pressure Pdis, and the exhaust superheat Tdsh.

In another example, the control program is executed by theprocessor 20 to implement the steps of:

step S1', when theair conditioning system 10 is operating in the pure heating mode, determining the number of currently openexternal heat exchangers 112;

step S2', acquiring exhaust superheat Tdsh, system temperature Te and outdoor environment temperature To; and

in step S3', the number of theouter heat exchangers 112 that are turned on is adjusted based on the number of theouter heat exchangers 112 that are currently turned on, the degree of superheat Tdsh of the exhaust gas, the system temperature Te, and the outdoor ambient temperature To.

In theair conditioning system 10, theprocessor 20 may execute a control program to adjust the operation state of theouter heat exchanger 112 according to the actual requirement of theair conditioning system 10 on theouter heat exchanger 112, so as to ensure that theair conditioning system 10 can operate reliably and stably. Thus, theair conditioning system 10 can flexibly adapt to actual use requirements while ensuring the reliability of system operation.

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

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 specific logical functions or steps of the 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, such as 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, processing module-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 embodiments 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. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are 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 by the method for 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 when the program is executed, the program 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 in the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (13)

1. A control method for an air conditioning system, the air conditioning system including an outdoor unit including an external heat exchanger, the external heat exchanger being plural in number, the control method comprising:

determining the current opening number of the outer heat exchangers when the air conditioning system is in operation;

acquiring the exhaust pressure and the exhaust superheat degree of the air conditioning system, or acquiring the exhaust superheat degree, the system temperature and the outdoor environment temperature, wherein the system temperature comprises the saturation temperature corresponding to the middle temperature or the return air pressure of an evaporator; and

and adjusting the number of the opened outer heat exchangers according to the number of the opened outer heat exchangers currently, the exhaust pressure and the exhaust superheat degree, or according to the number of the opened outer heat exchangers currently, the exhaust superheat degree, the system temperature and the outdoor environment temperature.

2. The control method according to claim 1, wherein the step of adjusting the number of the outer heat exchanger openings based on the number of the outer heat exchanger openings, the discharge pressure, and the discharge superheat, or based on the number of the outer heat exchanger openings, the discharge superheat, the system temperature, and the outdoor ambient temperature comprises:

and when the air conditioning system operates in a cooling mode, adjusting the opening number of the outer heat exchanger according to the current opening number of the outer heat exchanger, the exhaust pressure and the exhaust superheat degree.

3. The control method as set forth in claim 2, wherein said step of adjusting the number of the outer heat exchanger openings based on the number of the outer heat exchanger currently opening, the discharge pressure and the discharge superheat degree when the air conditioning system is operating in the cooling mode comprises:

when the exhaust pressure is greater than a first preset pressure and lasts for a first time period, increasing the number of the opened external heat exchangers; and

and when the exhaust pressure is less than or equal to a second preset pressure and lasts for a second time period, the exhaust superheat degree is less than or equal to a first preset value and lasts for a third time period, or the exhaust pressure is less than or equal to a third preset pressure and lasts for a fourth time period, the number of the opened external heat exchangers is reduced, the first preset pressure is greater than the second preset pressure, and the second preset pressure is greater than the third preset pressure.

4. The control method according to claim 1, wherein the step of adjusting the number of the outer heat exchanger openings based on the number of the outer heat exchanger openings, the discharge pressure, and the discharge superheat, or based on the number of the outer heat exchanger openings, the discharge superheat, the system temperature, and the outdoor ambient temperature comprises:

and when the air conditioning system operates in a heating mode, adjusting the number of the opened external heat exchangers according to the number of the currently opened external heat exchangers, the exhaust superheat degree, the system temperature and the outdoor environment temperature.

5. The control method as set forth in claim 4, wherein said step of adjusting the number of the external heat exchanger to be turned on based on the number of the external heat exchanger to be turned on currently, the degree of superheat of the exhaust gas, the system temperature and the outdoor ambient temperature while the air conditioning system is operating in the heating mode comprises:

when the difference value between the outdoor environment temperature and the system temperature is greater than or equal to a second preset value, increasing the number of the opened external heat exchangers; and

and when the difference between the outdoor environment temperature and the system temperature is less than or equal to a third preset value and the exhaust superheat degree is less than or equal to a fourth preset value for a fifth time, reducing the number of the opened external heat exchangers, wherein the second preset value is greater than the third preset value.

6. The control method according to claim 1, characterized by comprising:

and after the air conditioning system runs for a preset time, adjusting the number of the opened external heat exchangers according to the number of the currently opened external heat exchangers, the exhaust pressure and the exhaust superheat degree, or according to the number of the currently opened external heat exchangers, the exhaust superheat degree, the system temperature and the outdoor environment temperature.

7. An air conditioning system, comprising an outdoor unit and a control device, wherein the outdoor unit comprises an external heat exchanger, the number of the external heat exchanger is multiple, the control device is used for determining the number of the current opening of the external heat exchanger when the air conditioning system is in operation, and is used for obtaining the exhaust pressure and the exhaust superheat degree of the air conditioning system, or obtaining the exhaust superheat degree, the system temperature and the outdoor environment temperature, wherein the system temperature comprises the saturation temperature corresponding to the middle temperature or the return air pressure of an evaporator, and is used for adjusting the number of the opening of the external heat exchanger according to the number of the current opening of the external heat exchanger, the exhaust pressure and the exhaust superheat degree, or according to the number of the current opening of the external heat exchanger, the exhaust superheat degree, the system temperature and the outdoor environment temperature.

8. The air conditioning system as claimed in claim 7, wherein said control means is adapted to adjust the number of times said outer heat exchanger is turned on based on the number of times said outer heat exchanger is currently turned on, said discharge pressure, and said discharge superheat degree when said air conditioning system is operating in a cooling mode.

9. The air conditioning system as claimed in claim 8, wherein the control means is configured to increase the number of the open of the outer heat exchanger when the discharge pressure is greater than a first preset pressure for a first period of time, and to decrease the number of the open of the outer heat exchanger when the discharge pressure is less than or equal to a second preset pressure for a second period of time and the discharge superheat is less than or equal to a first preset value for a third period of time, or the discharge pressure is less than or equal to a third preset pressure for a fourth period of time, the first preset pressure being greater than the second preset pressure, the second preset pressure being greater than the third preset pressure.

10. The air conditioning system as claimed in claim 7, wherein said control means is adapted to adjust the number of the external heat exchangers that are turned on based on the number of the external heat exchangers that are currently turned on, the degree of superheat of the exhaust gas, the system temperature, and the outdoor ambient temperature when the air conditioning system is operating in the heating mode.

11. The air conditioning system as claimed in claim 10, wherein the control means is adapted to increase the number of the external heat exchanger being turned on when the difference between the outdoor ambient temperature and the system temperature is greater than or equal to a second preset value, and to decrease the number of the external heat exchanger being turned on when the difference between the outdoor ambient temperature and the system temperature is less than or equal to a third preset value and the degree of superheat of the discharge air is less than or equal to a fourth preset value for a fifth time period, the second preset value being greater than the third preset value.

12. The air conditioning system as claimed in claim 7, wherein the control means is adapted to adjust the number of the outer heat exchangers that are turned on based on the number of the outer heat exchangers that are currently turned on, the discharge pressure, and the discharge superheat degree, or based on the number of the outer heat exchangers that are currently turned on, the discharge superheat degree, the system temperature, and the outdoor ambient temperature, after the air conditioning system is operated for a preset period of time.

13. An air conditioning system comprising an outdoor unit including a plurality of external heat exchangers, a processor, and a memory, wherein the memory stores a control program executed by the processor to implement the control method according to any one of claims 1 to 6.

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