Refrigerant quantity control method and control device of multi-split air conditioner and multi-split air conditioner

Abstract

The invention relates to the technical field of air conditioners, and provides a refrigerant amount control method and device of a multi-split air conditioner and the multi-split air conditioner, and the refrigerant amount control method comprises the steps that the operation mode of the multi-split air conditioner is obtained, and the real-time superheat degree of a heat exchanger corresponding to the operation mode and the first target superheat degree of the heat exchanger are obtained; when the real-time superheat degree is larger than the first target superheat degree, the multiple indoor units in the standby state are controlled to recycle refrigerants in the system according to the starting frequency from low to high; wherein the indoor unit recycles the refrigerant in the system, namely the refrigerant is sealed between the first electronic expansion valve and the second electronic expansion valve. When the multi-split air conditioner runs, the refrigerant in the system is recycled or released through the indoor unit in the standby state, the amount of the refrigerant in the system can be adjusted without additionally arranging a refrigerant recycling pipeline or refrigerant recycling equipment, and the multi-split air conditioner is convenient to use.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a refrigerant quantity control method and control device of a multi-split air conditioner, and the multi-split air conditioner. Background Art

[0002] The refrigerant in the air-conditioning system circulates in the system, and as the state of the refrigerant changes, cooling operation or heating operation can be achieved. If you want to achieve the optimal value of cooling or heating capacity, the refrigerant in the heat exchanger must be able to evaporate completely. Therefore, when the air-conditioning system is operated under different installation conditions and different working conditions, the amount of refrigerant required is different. In the related art, in order to adjust the amount of refrigerant in the air-conditioning system, it is often necessary to set up an independent refrigerant recovery pipeline or refrigerant recovery equipment. When the amount of refrigerant in the air-conditioning system is large, the refrigerant in the air-conditioning system is partially recovered through the refrigerant recovery pipeline or refrigerant recovery equipment, and it is replenished again when the refrigerant is scarce. This method will increase the hardware cost of the air-conditioning system, and the layout of the refrigerant recovery pipeline and the refrigerant recovery equipment is more complicated when used. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention proposes a refrigerant quantity control method for a multi-split air conditioner, which can recover or release the refrigerant in the system through the indoor unit in the standby state, and can adjust the refrigerant quantity in the system without adding a new refrigerant recovery pipeline or refrigerant recovery equipment, which is more convenient to use.

[0004] The present invention also provides a refrigerant quantity control device for a multi-split air conditioner.

[0005] The invention also provides a multi-split air conditioner.

[0006] According to a first aspect of the present invention, a refrigerant quantity control method for a multi-split air conditioner is provided, wherein the multi-split air conditioner comprises a plurality of indoor units connected in parallel, wherein an inlet of each indoor unit is provided with a first electronic expansion valve, and an outlet of each indoor unit is provided with a second electronic expansion valve, and the refrigerant quantity control method comprises:

[0007] Acquire an operation mode of the multi-split air conditioner, and acquire a real-time superheat of the heat exchanger corresponding to the operation mode and a first target superheat of the heat exchanger;

[0008] When the real-time superheat is greater than the first target superheat, the multiple indoor units in standby state are controlled to recover the refrigerant in the system in order of startup frequency from low to high; wherein, the indoor unit recovers the refrigerant in the system by sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve.

[0009] According to an embodiment of the present invention, the startup frequencies of the plurality of indoor units are acquired in descending order through the following steps:

[0010] When obtaining the power-on signal of the indoor unit, updating the corresponding power-on frequency of the indoor unit;

[0011] The startup frequencies of the plurality of indoor units are sorted at each preset time interval or each shutdown.

[0012] According to an embodiment of the present invention, the step of controlling the plurality of indoor units in the standby state to recover the refrigerant in the system in order of the startup frequency from low to high, further includes:

[0013] Obtaining the real-time superheat;

[0014] Determining the current refrigerant state of the multi-split air conditioner according to the real-time superheat, the first target superheat, the second target superheat corresponding to the heat exchanger, and a predetermined state correspondence relationship; wherein the current refrigerant state includes a refrigerant excess state, a refrigerant moderate state, and a refrigerant shortage state;

[0015] When the current refrigerant state is the refrigerant excess state, controlling the remaining indoor units in the standby state to recycle the refrigerant in the system in order of the start-up frequency from low to high;

[0016] When the current refrigerant state is the refrigerant shortage state, the indoor units that have recovered the refrigerant are controlled to release the refrigerant into the system in order of the start-up frequency from high to low.

[0017] According to an embodiment of the present invention, the step of determining the current refrigerant state of the multi-split air conditioner according to the real-time superheat, the first target superheat, the second target superheat corresponding to the heat exchanger, and a predetermined state correspondence relationship specifically includes:

[0018] When the real-time superheat is greater than the first target superheat, the current refrigerant state is a refrigerant excess state;

[0019] When the real-time superheat is between the first target superheat and the second target superheat, the current refrigerant state is a moderate refrigerant state; wherein the second target superheat is less than the first target superheat;

[0020] When the real-time superheat degree is less than the second target superheat degree, the current refrigerant state is a refrigerant shortage state.

[0021] According to an embodiment of the present invention, the step of obtaining the real-time superheat of the heat exchanger corresponding to the operation mode and the first target superheat of the heat exchanger specifically includes:

[0022] When the operation mode is a cooling mode, obtaining a real-time superheat degree of an outdoor heat exchanger and a first target superheat degree corresponding to the outdoor heat exchanger;

[0023] When the operation mode is the heating mode, the current superheat of each indoor heat exchanger is obtained, and the real-time superheat corresponding to the indoor heat exchanger is obtained according to the average value of all the current superheats, and the first target superheat corresponding to the indoor heat exchanger is obtained.

[0024] According to an embodiment of the present invention, when the operation mode is the cooling mode, the step of sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve specifically includes:

[0025] The first electronic expansion valve of the corresponding indoor unit is controlled to be opened, and the second electronic expansion valve of the corresponding indoor unit is controlled to be closed, and the first electronic expansion valve is controlled to be closed after a predetermined time.

[0026] According to an embodiment of the present invention, when the operation mode is the heating mode, the step of sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve specifically includes:

[0027] The second electronic expansion valve of the corresponding indoor unit is controlled to open, after a first time period, the first electronic expansion valve of the corresponding indoor unit is controlled to open, after a second time period, the first electronic expansion valve is controlled to close, and after a third time period, the second electronic expansion valve is controlled to close.

[0028] According to an embodiment of the present invention, when the current refrigerant state is a moderate refrigerant state, the multi-split air conditioner is controlled to stop refrigerant recovery.

[0029] According to a second aspect of the present invention, a refrigerant quantity control device for a multi-split air conditioner is provided, comprising:

[0030] An acquisition module, used to acquire an operation mode of the multi-split air conditioner, and acquire a real-time superheat of the heat exchanger corresponding to the operation mode and a first target superheat of the heat exchanger;

[0031] A control module is used to control the multiple indoor units in standby state to recover the refrigerant in the system in order of startup frequency from low to high when the real-time superheat is greater than the first target superheat; wherein the indoor units recovering the refrigerant in the system means sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve.

[0032] A multi-split air conditioner provided in accordance with an embodiment of the third aspect of the present invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the refrigerant quantity control method for the multi-split air conditioner provided in accordance with the embodiment of the first aspect of the present invention are implemented.

[0033] The above one or more technical solutions in the present invention have at least one of the following technical effects:

[0034] According to the refrigerant quantity control method of the multi-split air conditioner provided by the embodiment of the present invention, the multi-split air conditioner includes a plurality of indoor units connected in parallel, the inlet of each indoor unit is provided with a first electronic expansion valve, and the outlet of each indoor unit is provided with a second electronic expansion valve, and the refrigerant quantity control method includes: obtaining the operation mode of the multi-split air conditioner, and obtaining the real-time superheat of the heat exchanger corresponding to the operation mode and the first target superheat of the heat exchanger; when the real-time superheat is greater than the first target superheat, controlling the plurality of indoor units in the standby state to recycle the refrigerant in the system in order from low to high according to the start-up frequency; wherein the indoor unit recycles the refrigerant in the system means that the refrigerant is sealed between the first electronic expansion valve and the second electronic expansion valve. When the multi-split air conditioner provided by the embodiment of the present invention is in operation, the refrigerant in the system is recycled or released by the indoor unit in the standby state, and the refrigerant quantity in the system can be adjusted without adding a new refrigerant recovery pipeline or refrigerant recovery equipment, which is more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 One of the flow charts of the refrigerant quantity control method of the multi-split air conditioner provided in the embodiment of the present invention;

[0037] Figure 2 A second flow chart of a method for controlling the amount of refrigerant in a multi-split air conditioner provided in an embodiment of the present invention;

[0038] Figure 3 A schematic structural diagram of the indoor unit of a multi-split air conditioner in a cooling mode according to an embodiment of the present invention;

[0039] Figure 4 A schematic structural diagram of the indoor unit of a multi-split air conditioner in a heating mode according to an embodiment of the present invention;

[0040] Figure 5A schematic structural diagram of a refrigerant quantity control device for a multi-split air conditioner provided in an embodiment of the present invention;

[0041] Figure 6 A schematic structural diagram of an electronic device of a multi-split air conditioner provided in an embodiment of the present invention.

[0042] Reference numerals:

[0043] 100, indoor unit; 11, first electronic expansion valve; 12, second electronic expansion valve;

[0044] 301, acquisition module; 302, control module. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the invention clearer, the technical solution in the invention will be clearly described below in conjunction with the drawings in the invention. Obviously, the described embodiments are part of the embodiments of the invention, not all of the embodiments. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the invention.

[0046] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0047] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0048] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0049] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0050] In the related art, in order to adjust the amount of refrigerant in the air-conditioning system, it is often necessary to set up an independent refrigerant recovery pipeline or refrigerant recovery equipment. When the amount of refrigerant in the air-conditioning system is large, the refrigerant in the refrigerant circulation loop is collected through the refrigerant recovery pipeline or the refrigerant recovery equipment, and replenished again when the refrigerant is scarce. This method will increase the hardware cost of the air-conditioning system, and the setting of the refrigerant recovery pipeline and the refrigerant recovery equipment is more complicated when used.

[0051] The multi-split air conditioner of the present invention comprises a plurality of indoor units 100 connected in parallel. Figure 3 and Figure 4 Each indoor unit is provided with an inlet and an outlet. When the multi-split air conditioner operates in cooling mode, the refrigerant enters the indoor heat exchanger of the indoor unit along the inlet, and the refrigerant flows out along the outlet after heat exchange; when the multi-split air conditioner operates in heating mode, the refrigerant enters the indoor heat exchanger of the indoor unit along the outlet, and the refrigerant flows out along the inlet after heat exchange. In order to adjust the refrigerant temperature and refrigerant flow in each indoor heat exchanger, a first electronic expansion valve 11 is provided at the inlet, and a second electronic expansion valve 12 is provided at the outlet.

[0052] It can be seen from the above that the multi-split air conditioner according to the present invention does not require any additional refrigerant recovery pipeline or refrigerant recovery equipment.

[0053] At the same time, the multi-split air conditioner involved in the embodiment of the present invention also includes conventional temperature sensors, pressure sensors, wind speed detection elements, etc., and conventional detection components commonly used in existing related equipment can be used. These electronic components are set according to needs.

[0054] According to the first aspect of the present invention, the refrigerant quantity control method of the multi-split air conditioner is provided. Figure 1 ,include:

[0055] S100: Acquire an operation mode of the multi-split air conditioner, and acquire a real-time superheat of the heat exchanger corresponding to the operation mode and a first target superheat of the heat exchanger.

[0056] In step S100, the operation mode of the multi-split air conditioner includes at least a cooling mode and a heating mode. The amount of refrigerant required by the refrigerant circulation loop of the multi-split air conditioner is different in different operation modes. Therefore, it is necessary to determine appropriate operation parameters according to the operation mode, and then determine whether the current amount of refrigerant in the system meets the demand according to the operation parameters. In the cooling mode or the heating mode, the change of the amount of refrigerant is more obvious at the indoor heat exchanger or the outdoor heat exchanger. Therefore, the sufficiency of the amount of refrigerant can be measured according to the real-time superheat of the indoor heat exchanger or the outdoor heat exchanger. For example, in the cooling mode, the refrigerant state is determined according to the relationship between the real-time superheat of the outdoor heat exchanger and the corresponding first target superheat. In the heating mode, the refrigerant state is determined according to the relationship between the real-time superheat of the indoor heat exchanger and the corresponding first target superheat. The refrigerant state includes an excess refrigerant state, a moderate refrigerant state, and a shortage refrigerant state. Different refrigerant states require different control measures.

[0057] S120. When the real-time superheat is greater than the first target superheat, control the multiple indoor units in standby state to recover the refrigerant in the system in order of the start-up frequency from low to high; wherein, the indoor unit recovers the refrigerant in the system means sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve.

[0058] In step S120, when the real-time superheat is greater than the first target superheat, it proves that the amount of refrigerant in the multi-split air conditioning system is too much, and part of the refrigerant needs to be recovered. At this time, the multiple indoor units in the standby state are controlled to recover the refrigerant in the system in order of the start-up frequency from low to high. The start-up frequency refers to the number of startups of the corresponding indoor unit within a period of time. The lower the start-up frequency, the lower the probability that the indoor unit is instructed to run during the working process. The refrigerant in the system is recovered by the indoor unit with the lowest start-up frequency. On the one hand, the amount of refrigerant in the system can be adjusted, on the other hand, the stable operation of the system can be maintained, and the instruction change in the middle can be avoided. On the third hand, no additional refrigerant recovery pipeline and refrigerant recovery equipment are required. Among them, the indoor unit recovers the refrigerant in the system, which means that the refrigerant is sealed between the first electronic expansion valve and the second electronic expansion valve, that is, the electronic expansion valve at the downstream of the indoor unit is opened first, and after the refrigerant enters the corresponding indoor unit under the action of the refrigerant pressure in the pipeline, the electronic expansion valve at the upstream of the indoor unit is closed, so that part of the refrigerant can be sealed in the indoor unit. When operating in cooling mode or heating mode, the direction in which the refrigerant flows through the indoor unit is different, and the upstream electronic expansion valve may be the first electronic expansion valve or the second electronic expansion valve, which is determined in combination with the actual operating mode.

[0059] At the same time, when the problem of excessive refrigerant cannot be solved by recovering part of the refrigerant through the indoor unit with the lowest startup frequency, the refrigerant in the system is recovered through the indoor unit with the second lowest startup frequency, and so on, until the real-time superheat meets the predetermined conditions, that is, it is within a certain superheat range.

[0060] In some embodiments, the power-on frequencies of multiple indoor units are obtained in descending order through the following steps:

[0061] S121. When a power-on signal of an indoor unit is obtained, the power-on frequency of the corresponding indoor unit is updated.

[0062] S122. Sort the power-on frequencies of the multiple indoor units at every preset time interval or each time the indoor units are turned off.

[0063] It is understandable that each time the controller sends a signal to control the indoor unit to start up, a start-up record corresponding to the indoor unit is generated at the same time, and the start-up frequency of the indoor unit increases, and the start-up frequency data is updated in time. At each preset time interval, such as 24 hours, or each time the unit is shut down, the start-up frequencies of multiple indoor units are sorted, and an order from low to high or from high to low can be obtained. Even if some indoor units are in the start-up state / maintenance state, it still does not affect the sorting of other indoor units in the standby state.

[0064] In some embodiments, the step of controlling multiple indoor units in a standby state to recover the refrigerant in the system in order of starting frequency from low to high may further include:

[0065] S140: Obtain real-time superheat.

[0066] S150. Determine the current refrigerant state of the multi-split air conditioner according to the real-time superheat, the first target superheat, the second target superheat corresponding to the heat exchanger, and a predetermined state correspondence; wherein the current refrigerant state includes a refrigerant excess state, a refrigerant moderate state, and a refrigerant shortage state.

[0067] See also Figure 2 After adjusting the system refrigerant quantity of the multi-split air conditioner, the real-time superheat can meet the demand during adjustment. While the multi-split air conditioner continues to work, the external environment will change, such as temperature drop, rain, snow, etc. At this time, the refrigerant demand in the multi-split air conditioner will also change, requiring timely feedback and adjustment. After controlling multiple indoor units in standby state to recycle the refrigerant in the system in order from low to high power-on frequency, it is still necessary to set a feedback adjustment step so that the refrigerant quantity in the multi-split air conditioner can adapt to the needs of different working conditions and different environmental changes.

[0068] S161. When the current refrigerant state is a refrigerant excess state, control the remaining indoor units in the standby state to recycle the refrigerant in the system in order of startup frequency from low to high.

[0069] It is understandable that if the current refrigerant status is the refrigerant excess status, it means that after partially recovering the refrigerant in the system, combined with the current environmental factors, there is still a refrigerant excess situation, and further refrigerant recovery is required. At this time, the remaining indoor units in the standby state are controlled to recover the refrigerant in the system in order of the power-on frequency from low to high.

[0070] S162: When the current refrigerant state is a refrigerant shortage state, control the indoor units that have recovered the refrigerant to release the refrigerant into the system in order of the start-up frequency from high to low.

[0071] It is understandable that if the current refrigerant status is a refrigerant shortage status, it means that after partially recovering the refrigerant in the system, combined with the current environmental factors, there is an excess of refrigerant recovery, and some refrigerant needs to be released. At this time, the indoor units that have recovered the refrigerant are controlled to release the refrigerant to the system in order from high to low start-up frequency, that is, the indoor units with higher start-up frequency are controlled to release the refrigerant first, and the indoor units with lower start-up frequency are controlled to release the refrigerant later, which helps to maintain the stability of refrigerant recovery.

[0072] In some embodiments, when the current refrigerant state is a moderate refrigerant state, the multi-split air conditioner is controlled to stop refrigerant recovery.

[0073] It is understandable that if the current refrigerant state is a moderate refrigerant state, it means that after partially recovering the refrigerant in the system, combined with the current environmental factors, the amount of refrigerant is appropriate, and there is no need to continue to recover the refrigerant or release the refrigerant. It is sufficient to maintain the current amount of refrigerant.

[0074] In some embodiments, the step of determining the current refrigerant state of the multi-split air conditioner according to the real-time superheat, the first target superheat, the second target superheat corresponding to the heat exchanger, and the predetermined state correspondence relationship specifically includes:

[0075] When the real-time superheat is greater than the first target superheat, the current refrigerant state is a refrigerant excess state.

[0076] When the real-time superheat is between the first target superheat and the second target superheat, the current refrigerant state is a moderate refrigerant state; wherein the second target superheat is less than the first target superheat.

[0077] When the real-time superheat is less than the second target superheat, the current refrigerant state is a refrigerant shortage state.

[0078] It can be understood that when the real-time superheat is greater than the first target superheat, the system does not need so much refrigerant, and the current refrigerant state is a refrigerant excess state; when the real-time superheat is between the first target superheat and the second target superheat, the refrigerant amount in the system is in a reasonable range and does not need to be adjusted, then the current refrigerant state is a refrigerant moderate state; when the real-time superheat is less than the second target superheat, the refrigerant amount in the system is insufficient, proving that the current refrigerant state is a refrigerant shortage state.

[0079] In some embodiments, the step of obtaining the real-time superheat of the heat exchanger corresponding to the operation mode and the first target superheat of the heat exchanger specifically includes:

[0080] When the operation mode is the cooling mode, the real-time superheat degree of the outdoor heat exchanger and the first target superheat degree corresponding to the outdoor heat exchanger are obtained.

[0081] It can be understood that when the operating mode is cooling mode, the saturation temperature corresponding to the pressure value detected by the high-pressure pressure sensor of the outdoor heat exchanger and the outdoor heat exchanger outlet temperature can be obtained, and the difference between the two is the real-time superheat of the outdoor heat exchanger; in order to make the multi-split air conditioner operate in cooling mode stably, there is a predetermined first target superheat, and under the first target superheat, the outdoor heat exchanger can efficiently exchange heat.

[0082] When the operation mode is heating mode, the current superheat of each indoor heat exchanger is obtained, and the real-time superheat corresponding to the indoor heat exchanger is obtained according to the average value of all current superheats, and the first target superheat corresponding to the indoor heat exchanger is obtained.

[0083] It is understandable that when the operation mode is heating mode, there are multiple running indoor units, then the current superheat of each indoor heat exchanger is obtained, and the current superheat is the difference between the saturation temperature corresponding to the pressure value detected by the pressure sensor of each indoor unit and the outlet temperature of the indoor heat exchanger, and the average value of all current superheat is calculated to obtain the real-time superheat corresponding to the indoor heat exchanger. In order to make the multi-split air conditioner stably operate in cooling mode, there is a first target superheat corresponding to the indoor unit, and under the first target superheat, the indoor heat exchanger can efficiently exchange heat.

[0084] In some embodiments, when the operation mode is the cooling mode, the step of sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve specifically includes:

[0085] The first electronic expansion valve of the corresponding indoor unit is controlled to be opened, and the second electronic expansion valve of the corresponding indoor unit is controlled to be closed. After a predetermined time, the first electronic expansion valve is controlled to be closed.

[0086] It can be understood that when the indoor units are made to recycle refrigerant in the order of startup frequency, the first electronic expansion valve of the corresponding indoor unit is opened first, and the corresponding second electronic expansion valve is controlled to be closed. At this time, the refrigerant enters the corresponding indoor unit under the action of the refrigerant pressure, but does not continue to flow along the second electronic expansion valve. After a predetermined period of time, the indoor unit collects a portion of the refrigerant. At this time, the first electronic expansion valve is closed, and part of the refrigerant can be temporarily sealed in the indoor unit, reducing the amount of refrigerant in the system.

[0087] According to one embodiment of the present invention, when the operation mode is the heating mode, the step of sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve specifically includes:

[0088] The second electronic expansion valve of the corresponding indoor unit is controlled to open, the first electronic expansion valve of the corresponding indoor unit is controlled to open after a first time period, the first electronic expansion valve is controlled to close after a second time period, and the second electronic expansion valve is controlled to close after a third time period.

[0089] It can be understood that when running in heating mode, the refrigerant about to enter the indoor unit is in liquid state, and it is necessary to open the second electronic expansion valve and the first electronic expansion valve first to allow the gaseous refrigerant in the corresponding indoor unit to flow out, and then close the first electronic expansion valve to intercept a part of the refrigerant, and seal this part of the refrigerant in the indoor unit through the second electronic expansion valve.

[0090] According to the second aspect of the present invention, the refrigerant quantity control device for a multi-split air conditioner is provided. Figure 5 ,include:

[0091] The acquisition module 301 is used to acquire the operation mode of the multi-split air conditioner, and acquire the real-time superheat of the heat exchanger corresponding to the operation mode and the first target superheat of the heat exchanger.

[0092] The control module 302 is used to control multiple indoor units in standby state to recycle the refrigerant in the system in order of startup frequency from low to high when the real-time superheat is greater than the first target superheat; wherein the indoor unit recycles the refrigerant in the system means sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve.

[0093] It should be noted that the above steps S100 to S120, as well as other steps, are only for the convenience of description and do not constitute a time sequence limitation for each step in the refrigerant quantity control method for a multi-split air conditioner. In addition, some contents are described in detail in the refrigerant quantity control method for a multi-split air conditioner provided in the first aspect embodiment, and the contents in all the refrigerant quantity control methods for a multi-split air conditioner are also applicable to the refrigerant quantity control device for a multi-split air conditioner provided in the second aspect embodiment, and in order to avoid repetition, the refrigerant quantity control device for a multi-split air conditioner provided in the second aspect embodiment is not described in detail. Similarly, the contents in the above two aspects of the embodiments can be used to explain the contents of all the following aspects of the embodiments, so the repeated contents will not be repeated in the following embodiments. The refrigerant quantity control device for a multi-split air conditioner provided in accordance with the embodiment of the present invention has a technical effect corresponding to the technical effect of the refrigerant quantity control method for a multi-split air conditioner, and will not be repeated here.

[0094] A multi-split air conditioner provided in accordance with an embodiment of the third aspect of the present invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the refrigerant quantity control method for the multi-split air conditioner provided in accordance with the embodiment of the first aspect of the present invention are implemented.

[0095] Figure 6The physical structure diagram of an electronic device of a multi-split air conditioner is illustrated, and the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the refrigerant quantity control method of the multi-split air conditioner, and the method includes: obtaining the operation mode of the multi-split air conditioner, and obtaining the real-time superheat of the heat exchanger corresponding to the operation mode and the first target superheat of the heat exchanger; when the real-time superheat is greater than the first target superheat, controlling multiple indoor units in the standby state to recycle the refrigerant in the system in order from low to high according to the start-up frequency; wherein the indoor unit recycles the refrigerant in the system means sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve.

[0096] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0097] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0098] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the amount of refrigerant in a multi-split air conditioner, characterized in that: The multi-split air conditioner includes a plurality of indoor units connected in parallel, the inlet of each indoor unit is provided with a first electronic expansion valve, and the outlet of each indoor unit is provided with a second electronic expansion valve. The refrigerant quantity control method includes: Acquire an operation mode of the multi-split air conditioner, and acquire a real-time superheat of the heat exchanger corresponding to the operation mode and a first target superheat of the heat exchanger; When the real-time superheat is greater than the first target superheat, the multiple indoor units in standby state are controlled to recover the refrigerant in the system in order of startup frequency from low to high; wherein, the indoor units recovering the refrigerant in the system refers to sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve.

2. The refrigerant quantity control method of a multi-split air conditioner according to claim 1, characterized in that: The power-on frequencies of the multiple indoor units are obtained in descending order through the following steps: When obtaining the power-on signal of the indoor unit, updating the corresponding power-on frequency of the indoor unit; The startup frequencies of the plurality of indoor units are sorted at each preset time interval or each shutdown.

3. The refrigerant quantity control method of a multi-split air conditioner according to claim 1, characterized in that: The step of controlling the plurality of indoor units in the standby state to recover the refrigerant in the system in order of starting frequency from low to high, further comprises: Obtaining the real-time superheat; Determining the current refrigerant state of the multi-split air conditioner according to the real-time superheat, the first target superheat, the second target superheat corresponding to the heat exchanger, and a predetermined state correspondence relationship; wherein the current refrigerant state includes a refrigerant excess state, a refrigerant moderate state, and a refrigerant shortage state; When the current refrigerant state is the refrigerant excess state, controlling the remaining indoor units in the standby state to recycle the refrigerant in the system in order of the start-up frequency from low to high; When the current refrigerant state is the refrigerant shortage state, the indoor units that have recovered the refrigerant are controlled to release the refrigerant into the system in order of the start-up frequency from high to low.

4. The refrigerant quantity control method of a multi-split air conditioner according to claim 3, characterized in that: The step of determining the current refrigerant state of the multi-split air conditioner according to the real-time superheat, the first target superheat, the second target superheat corresponding to the heat exchanger, and a predetermined state correspondence relationship specifically includes: When the real-time superheat is greater than the first target superheat, the current refrigerant state is a refrigerant excess state; When the real-time superheat is between the first target superheat and the second target superheat, the current refrigerant state is a moderate refrigerant state; wherein the second target superheat is less than the first target superheat; When the real-time superheat degree is less than the second target superheat degree, the current refrigerant state is a refrigerant shortage state.

5. The refrigerant quantity control method of a multi-split air conditioner according to any one of claims 1 to 4, characterized in that: The step of obtaining the real-time superheat of the heat exchanger corresponding to the operation mode and the first target superheat of the heat exchanger specifically includes: When the operation mode is a cooling mode, obtaining a real-time superheat degree of an outdoor heat exchanger and a first target superheat degree corresponding to the outdoor heat exchanger; When the operation mode is the heating mode, the current superheat of each indoor heat exchanger is obtained, and the real-time superheat corresponding to the indoor heat exchanger is obtained according to the average value of all the current superheats, and the first target superheat corresponding to the indoor heat exchanger is obtained.

6. The refrigerant quantity control method of a multi-split air conditioner according to claim 5, characterized in that: When the operation mode is the cooling mode, the step of sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve specifically includes: The first electronic expansion valve of the corresponding indoor unit is controlled to be opened, and the second electronic expansion valve of the corresponding indoor unit is controlled to be closed, and the first electronic expansion valve is controlled to be closed after a predetermined time.

7. The refrigerant quantity control method of a multi-split air conditioner according to claim 5, characterized in that: When the operation mode is the heating mode, the step of sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve specifically includes: The second electronic expansion valve of the corresponding indoor unit is controlled to open, after a first time period, the first electronic expansion valve of the corresponding indoor unit is controlled to open, after a second time period, the first electronic expansion valve is controlled to close, and after a third time period, the second electronic expansion valve is controlled to close.

8. The refrigerant quantity control method of a multi-split air conditioner according to claim 3, characterized in that: When the current refrigerant state is a moderate refrigerant state, the multi-split air conditioner is controlled to stop refrigerant recovery.

9. A refrigerant quantity control device for a multi-split air conditioner, characterized in that: include: An acquisition module, used to acquire an operation mode of the multi-split air conditioner, and acquire a real-time superheat of the heat exchanger corresponding to the operation mode and a first target superheat of the heat exchanger; A control module is used to control multiple indoor units in standby state to recover the refrigerant in the system in order of startup frequency from low to high when the real-time superheat is greater than the first target superheat; wherein the indoor unit recovers the refrigerant in the system by sealing the refrigerant between the first electronic expansion valve and the second electronic expansion valve.

10. A multi-split air conditioner, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the refrigerant quantity control method for a multi-split air conditioner as described in any one of claims 1 to 8 are implemented.

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