Multi-connected air conditioner, method and device for controlling multi-connected air conditioner

Abstract

The application relates to the technical field of multi-connected air conditioners, and discloses a multi-connected air conditioner, which comprises an outdoor unit and an indoor unit group, the indoor unit group comprises a plurality of parallelly connected indoor units; at least one indoor unit comprises a main flow path which comprises an electronic expansion valve and an indoor heat exchanger connected in sequence through a main pipeline; at least part of the pipeline of the main pipeline located at the refrigerant inlet end of the electronic expansion valve is used as a supercooling parallel connection section; a supercooling branch path comprises a supercooler; the supercooling branch path is parallelly connected with the supercooling parallel connection section; a switching communication assembly is configured to be controlled to communicate the supercooling parallel connection section and / or the supercooling branch path with the electronic expansion valve. The application can improve the pre-valve supercooling degree of the electronic expansion valve, and thus the refrigerant in the throttling process is more stable, so that the purpose of improving the throttling sound and abnormal sound of the indoor side of the multi-connected air conditioner is achieved. The application further discloses a method and device for controlling the multi-connected air conditioner.

Description

Technical Field

[0001] This application relates to the field of multi-split air conditioning technology, such as a multi-split air conditioner, a method and apparatus for controlling a multi-split air conditioner. Background Technology

[0002] Multi-split air conditioners consist of multiple indoor units connected in parallel, each including an indoor heat exchanger and an electronic expansion valve. During cooling operation, when the high-pressure liquid refrigerant enters the indoor unit and flows through the electronic expansion valve, insufficient subcooling before the valve (i.e., the refrigerant is in a two-phase state) causes unusually noticeable refrigerant throttling noise. This is especially problematic for multi-split air conditioners with long piping and significant elevation differences. Even if the refrigerant output from the outdoor unit has sufficient subcooling, insufficient subcooling before the electronic expansion valve in the indoor unit can still occur due to pipe pressure and heat losses, leading to throttling noise. This issue has consistently been a major source of user complaints.

[0003] In related technologies, by adding secondary subcooling equipment such as plate heat exchangers and double pipes to the outdoor unit, the subcooling degree at the liquid pipe outlet is increased to ensure that there is a certain degree of subcooling before the refrigerant reaches the electronic expansion valve on the user side, thereby solving the throttling noise problem to some extent. In implementing the embodiments of this disclosure, at least the following problems were found in the related technologies:

[0004] Since the indoor units of multi-split air conditioners are installed in different environments, even if the refrigerant on the outdoor side has a large subcooling degree, it cannot be guaranteed that the subcooling degree before the valve of each indoor unit will meet the requirements. Therefore, the improvement on the abnormal throttling noise is minimal. Summary of the Invention

[0005] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0006] This disclosure provides a multi-split air conditioner, a method and apparatus for controlling a multi-split air conditioner, to improve the problem of throttling noise on the indoor side of the multi-split air conditioner.

[0007] In some embodiments, the multi-split air conditioner includes an outdoor unit and an indoor unit, the indoor unit including a plurality of indoor units connected in parallel; at least one indoor unit includes: a main pipeline including an electronic expansion valve and an indoor heat exchanger connected in sequence via the main pipeline; wherein at least a portion of the main pipeline located at the refrigerant inlet end of the electronic expansion valve is used as a subcooling parallel section; a subcooling branch including a subcooler; the subcooling branch being connected in parallel with the subcooling parallel section; and a switching connection component configured to controllably connect the subcooling parallel section and / or the subcooling branch to the electronic expansion valve.

[0008] Optionally, the subcooler is located in the air field area on the air outlet side of the indoor heat exchanger.

[0009] Optionally, the indoor unit further includes: a main air duct, on which the indoor heat exchanger is disposed; a subcooling air duct, located downstream of the main air duct and connected in parallel with the main air duct, wherein the subcooler is disposed within the subcooling air duct; and the air inlet of the subcooling air duct is further provided with a damper, which is configured to controllably adjust its opening to change the airflow from the main air duct to the subcooling air duct.

[0010] Optionally, the switching connection component includes: a first solenoid valve disposed in the subcooled parallel section; and a second solenoid valve disposed in the subcooled branch.

[0011] In some embodiments, the method for controlling a multi-split air conditioner includes: in response to a cooling mode operation command, obtaining a current first subcooling degree at the refrigerant inlet of the electronic expansion valve; and when the current first subcooling degree is less than or equal to a first preset subcooling degree, controlling the switching connection component to connect the subcooling branch to the electronic expansion valve.

[0012] Optionally, obtaining the current first subcooling at the refrigerant inlet of the electronic expansion valve includes:

[0013] The current first subcooling is determined based on the difference between the current condensing temperature of the outdoor unit and the first refrigerant temperature at the refrigerant inlet of the electronic expansion valve.

[0014] Optionally, the current first subcooling degree can be obtained in the following manner:

[0015] SC j1 =k×TC-T 1,j1

[0016] Among them, SC j1 The current first subcooling, TC is the current condensation temperature, and T is the current condensation temperature. 1,j1 The temperature of the first refrigerant is k, and k is the subcooling correction parameter: k < 1.

[0017] Optionally, the control switching connection component to connect the subcooled branch to the electronic expansion valve includes:

[0018] The control switching connection component connects the subcooled branch to the electronic expansion valve, and disconnects the subcooled parallel section from the electronic expansion valve; or,

[0019] The control switching connection component connects both the subcooled branch and the subcooled parallel section to the electronic expansion valve.

[0020] Optionally, if the indoor unit includes a main air duct and a subcooling air duct, then after connecting the subcooling branch to the electronic expansion valve, the method further includes:

[0021] Obtain the second refrigerant temperature at the outlet end of the subcooled branch;

[0022] The current second subcooling degree at the refrigerant inlet of the electronic expansion valve is determined based on the difference between the current condensing temperature of the outdoor unit and the temperature of the second refrigerant.

[0023] Based on the preset subcooling range satisfied by the current second subcooling, the airflow from the main air duct to the subcooling air duct is controlled.

[0024] Optionally, the current second subcooling degree is obtained in the following manner:

[0025] SC j2 =k×TC-T l,j2

[0026] Among them, SC j2 The current second subcooling, TC is the current condensation temperature, and T is the current condensation temperature. 1,j2 The temperature of the second refrigerant is k, which is the subcooling correction parameter: k < 1.

[0027] Optionally, if the current second subcooling degree is less than or equal to the first preset subcooling degree, the airflow from the main air duct to the subcooling air duct is increased.

[0028] If the current second subcooling degree is greater than the second preset subcooling degree, the airflow from the main air duct to the subcooling air duct is reduced.

[0029] If the current second subcooling degree is greater than the first preset subcooling degree and less than or equal to the second preset subcooling degree, the airflow from the main air duct to the subcooling air duct is kept constant.

[0030] Optionally, if the subcooling duct is equipped with a damper for controlled adjustment of the opening to change the airflow from the main duct to the subcooling duct;

[0031] The increase in airflow from the main air duct to the subcooled air duct includes:

[0032] Based on the difference between the current second subcooling degree and the first preset subcooling degree, the damper is controlled to rotate in the direction of increasing the opening degree, so as to increase the airflow from the main air duct to the subcooling air duct;

[0033] Controlling the reduction of airflow from the main air duct to the subcooled air duct includes:

[0034] Based on the difference between the current second subcooling degree and the second preset subcooling degree, the damper is controlled to rotate in the direction of decreasing opening, so as to reduce the airflow from the main air duct to the subcooling air duct.

[0035] Optionally, when the outdoor ambient temperature is higher than the preset temperature, the current first subcooling degree of the refrigerant inlet of the electronic expansion valve is obtained;

[0036] When the outdoor ambient temperature is less than or equal to the preset temperature, the switching connection component is controlled to disconnect the subcooled branch from the electronic expansion valve.

[0037] In some embodiments, the apparatus for controlling a multi-split air conditioner includes: an acquisition module configured to acquire a current first subcooling degree at the refrigerant inlet of an electronic expansion valve in response to a cooling mode operation command; and a control module configured to control a switching connection component to connect the subcooling branch to the electronic expansion valve when the current first subcooling degree is less than or equal to a first preset subcooling degree.

[0038] In other embodiments, the apparatus for controlling a multi-split air conditioner includes a processor and a memory storing program instructions, the processor being configured to execute the method for controlling the multi-split air conditioner described above when the program instructions are executed.

[0039] The multi-split air conditioner, method, and apparatus for controlling the multi-split air conditioner provided in this disclosure can achieve the following technical effects:

[0040] By setting a subcooling parallel section before the refrigerant inlet of the electronic expansion valve in the indoor unit of a multi-split air conditioner, and a subcooling branch set in parallel with the subcooling parallel section, the refrigerant flow in the main flow of the indoor unit can be partially or completely passed through the subcooling branch before entering the refrigerant inlet of the electronic expansion valve by switching the connecting components. This increases the subcooling degree before the electronic expansion valve, thereby making the refrigerant more stable during the throttling process, and thus improving the throttling noise on the indoor side of the multi-split air conditioner.

[0041] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0042] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0043] Figure 1 This is a schematic diagram of the connection structure of the indoor unit of a multi-split air conditioner in related technologies;

[0044] Figure 2 This is a connection diagram of the indoor unit of a multi-split air conditioner provided in an embodiment of this disclosure;

[0045] Figure 3 This is a schematic diagram of the structure of an indoor unit of a multi-split air conditioner provided in an embodiment of this disclosure;

[0046] Figure 4 yes Figure 3 A cross-sectional schematic diagram of the indoor unit shown;

[0047] Figure 5 This is a schematic flowchart of a method for controlling a multi-split air conditioner provided in an embodiment of this disclosure;

[0048] Figure 6 This is a schematic flowchart of another method for controlling a multi-split air conditioner provided in an embodiment of this disclosure;

[0049] Figure 7 This is a schematic flowchart of another method for controlling a multi-split air conditioner provided in an embodiment of this disclosure;

[0050] Figure 8 This is a schematic diagram of a device for controlling a multi-split air conditioner according to an embodiment of this disclosure;

[0051] Figure 9 This is a schematic diagram of another device for controlling a multi-split air conditioner provided in an embodiment of this disclosure.

[0052] Wherein, 100: Indoor unit; 110: Air inlet; 120: Air outlet; 200: Main air path; 210: Electronic expansion valve; 220: Indoor heat exchanger; 230: Subcooling parallel section; 240: Main air duct; 300: Subcooling branch; 310: Subcooler; 320: Subcooling air duct; 330: Damper; 410: First solenoid valve; 420: Second solenoid valve. Detailed Implementation

[0053] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0054] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0055] Unless otherwise stated, the term "multiple" means two or more.

[0056] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0057] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0058] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0059] Figure 1 This is a schematic diagram of the connection structure of the indoor unit of a multi-split air conditioner in related technologies.

[0060] like Figure 1 As shown, the refrigerant circulation loop of the indoor unit 100 of the multi-split air conditioner consists of the main liquid pipe, electronic expansion valve 210, indoor heat exchanger 220, and main gas pipe connected in sequence (taking the refrigerant flow direction in cooling mode as an example). Simultaneously, to achieve air conditioning function, temperature sensors can be used to obtain the temperature at different locations in the refrigerant circulation loop, as well as the ambient temperature.

[0061] When running in cooling mode, the high-temperature and high-pressure refrigerant output from the outdoor unit flows directly into the indoor unit 100 through the main liquid pipe. Then, it is throttled by the electronic expansion valve 210 and becomes a low-temperature and low-pressure two-phase refrigerant. It then undergoes evaporation and heat exchange in the indoor heat exchanger and exchanges heat with the indoor air before delivering cool air into the room.

[0062] Thus, due to the differences in the refrigerant state before the electronic expansion valve (such as insufficient subcooling or the presence of gas-liquid two-phase flow), the throttling noise during the flow closure process of such refrigerant will be relatively large, usually producing a "hissing" sound. This sound will be particularly noticeable when the background noise in the room is relatively quiet.

[0063] Therefore, this solution proposes a new multi-split air conditioning form to improve throttling noise through structural improvements and control strategies.

[0064] Figure 2 This is a schematic diagram of the connection of the indoor unit of a multi-split air conditioner provided in an embodiment of this disclosure. Figure 3 This is a schematic diagram of the structure of the indoor unit of a multi-split air conditioner provided in an embodiment of this disclosure. Figure 4 yes Figure 3 The diagram shows a cross-sectional view of the indoor unit.

[0065] Combination Figures 2 to 4 As shown in the embodiments of this disclosure, a multi-split air conditioner includes an outdoor unit and an indoor unit, wherein the indoor unit includes multiple indoor units 100 connected in parallel. At least one indoor unit 100 of the multi-split air conditioner includes:

[0066] Main path 200 includes an electronic expansion valve 210 and an indoor heat exchanger 220 connected in sequence via the main path; wherein at least a portion of the main path located at the refrigerant inlet end of the electronic expansion valve 210 is used as a subcooled parallel section 230.

[0067] The subcooling branch 300 includes a subcooler 310; the subcooling branch 300 is connected in parallel with the subcooling parallel section 230;

[0068] The switching connection components are configured to controllably connect the subcooled parallel section 230 and / or the subcooled branch 300 to the electronic expansion valve 210.

[0069] Generally, a multi-split air conditioner includes one or more outdoor units and multiple indoor units. The indoor units are connected in parallel and linked to the outdoor units via corresponding piping to facilitate refrigerant flow. This embodiment uses one indoor unit of a multi-split air conditioner as an example to illustrate the solution. A structural diagram of the outdoor unit is not shown. Those skilled in the art can configure the indoor unit provided in this embodiment to connect the indoor and outdoor units, thereby forming a refrigerant circulation loop for the multi-split air conditioner. In other embodiments, the multi-split air conditioner may include one or more indoor units as described in this embodiment.

[0070] Here, by setting a subcooling parallel section before the refrigerant inlet end of the electronic expansion valve of the multi-split air conditioner indoor unit, and a subcooling branch set in parallel with the subcooling parallel section, the refrigerant flow of part or all of the main flow of the indoor unit enters the refrigerant inlet section of the electronic expansion valve after passing through the subcooling branch by switching the connecting components. This increases the subcooling degree before the electronic expansion valve, thereby making the refrigerant more stable during the throttling process, so as to improve the throttling noise on the indoor side of the multi-split air conditioner.

[0071] Optionally, the indoor heat exchanger 220 has an air inlet side and an air outlet side; the subcooler 310 is disposed in the air field area on the air outlet side of the indoor heat exchanger 220.

[0072] When the indoor heat exchanger exchanges heat with the air in cooling mode, such as Figure 2 The arrows indicate that air moves from the intake side to the outlet side, with the outlet side containing air at a relatively lower temperature after heat exchange. Thus, by placing the subcooler within this airflow area, some of the cold air from the outlet side of the indoor heat exchanger can be directed to the subcooler, increasing the subcooling of the refrigerant within the subcooler 310. Similarly, the increased subcooling increases the cooling capacity per unit mass flow rate of the working fluid, thereby compensating for the "cooling loss" caused by introducing this portion of cold air into the subcooler.

[0073] Here, the subcooler 310 can be a regenerator or a heat exchanger. For example, if a heat exchanger with a large fin spacing and a single row of finned tubes is used as the subcooler, then when it is installed on the air outlet side of the indoor heat exchanger, its structural design will not increase the air resistance and will have little impact on the normal air conditioning output of the air conditioner.

[0074] Furthermore, the indoor unit 100 also includes a main air duct 240 and a subcooling air duct 320.

[0075] The main air duct 240 is equipped with an indoor heat exchanger 220; the subcooling air duct 320 is located downstream of the main air duct 240 and is connected in parallel with the main air duct 240; the subcooler 310 is located inside the subcooling air duct 320; the air inlet of the subcooling air duct 320 is also equipped with a damper 330, which is configured to controllably adjust its opening to change the airflow from the main air duct 240 to the subcooling air duct 320.

[0076] Here, the airflow in the subcooling duct is a portion of the airflow drawn out from the main duct under the action of the damper; the outlet of the subcooling duct is connected to the main duct, meaning that the airflow in the subcooling duct exchanges heat with the subcooler before being discharged from the indoor unit through the main duct. The opening degree of the damper can be adjusted according to the subcooling degree of the refrigerant output by the subcooler, thereby ensuring a constant subcooling degree of the refrigerant before the valve, making the refrigerant flow through the throttling process more stable, and improving throttling noise.

[0077] Combination Figure 3 and Figure 4This section explains how to adjust the airflow from the main air duct to the subcooled air duct using dampers.

[0078] The indoor unit 100 includes an air inlet 110 and an air outlet 120; indoor air enters the main air duct 240 through the air inlet 110 and exchanges heat with the indoor heat exchanger 220. The cooled air after heat exchange enters the room through the air outlet 120.

[0079] Driven by a stepper motor, the damper 330 can rotate between positions A and B within the subcooling duct 320. When the damper 330 is in position A, the subcooling duct 320 is not connected to the main air duct 240, and air cannot enter the subcooling duct 320. When the damper 330 is in position B, the airflow from the main air duct 240 into the subcooling duct 320 is at its maximum. Therefore, by adjusting the opening of the damper 330, the airflow from the main air duct 240 to the subcooling duct 320 can be altered.

[0080] In this scheme, the direction of adjusting the damper 330 from position A to position B is used as the direction of adjusting the opening to increase the airflow; the direction of adjusting from position B to position A is used as the direction of adjusting the opening to decrease the airflow.

[0081] Optionally, the switching connection component includes a first solenoid valve 410, located in the subcooled parallel section 230; and a second solenoid valve 420, located in the subcooled branch 300. Thus, to connect the subcooled parallel section 230 to the electronic expansion valve 210, the first solenoid valve 410 is opened; to connect the subcooled branch 300 to the electronic expansion valve 210, the second solenoid valve 420 is opened.

[0082] Alternatively, the switching connection component can also be a three-way valve. By placing the three-way valve at the inlet end of the parallel connection between the subcooling branch 300 and the subcooling parallel section 230, the inlet end of the three-way valve is connected to the main flow 200, the first outlet end is connected to the subcooling parallel section 230, and the second outlet end is connected to the subcooling branch 300. Thus, to connect the subcooling parallel section 230 to the electronic expansion valve 210, the control inlet end is connected to the first outlet end; to connect the subcooling branch 300 to the electronic expansion valve 210, the control inlet end is connected to the second outlet end.

[0083] The following section explains the refrigerant flow direction within the indoor unit of a multi-split air conditioner in cooling mode, based on the different states of the switching connection device.

[0084] When the switching device connects the subcooling parallel section 230 to the electronic expansion valve 210 and disconnects the subcooling branch 300 from the electronic expansion valve 210, the first solenoid valve 410 opens and the second solenoid valve 420 closes. The refrigerant input from the outdoor unit passes through the main flow path 200, enters the electronic expansion valve 210 from the subcooling parallel section 230 for throttling, and then enters the indoor heat exchanger 220 for evaporative heat exchange. After exchanging heat with the indoor air, it flows out of the indoor unit 100.

[0085] When the switching device disconnects the subcooling parallel section 230 from the electronic expansion valve 210 and connects the subcooling branch 300 to the electronic expansion valve 210, the first solenoid valve 410 is disconnected and the second solenoid valve 420 is opened. The refrigerant input from the outdoor unit enters through the main flow path 200 and then enters the subcooling branch 300. At this time, the refrigerant is subcooled in the subcooling branch 300. The refrigerant with increased subcooling degree enters the electronic expansion valve 210 for throttling. After throttling, it enters the indoor heat exchanger 220 for evaporative heat exchange. After exchanging heat with the indoor air, it flows out of the indoor unit 100.

[0086] When the switching device connects the subcooling parallel section 230 to the electronic expansion valve 210 and the subcooling branch 300 to the electronic expansion valve 210, the first solenoid valve 410 and the second solenoid valve 420 are opened. The refrigerant input from the outdoor unit enters the subcooling parallel section 230 and the subcooling branch 300 for subcooling adjustment after passing through the main flow path 200. Then, the two refrigerants are input into the electronic expansion valve 210 for throttling. After throttling, they enter the indoor heat exchanger 220 for evaporative heat exchange. After exchanging heat with the indoor air, they flow out of the indoor unit 100.

[0087] Thus, by setting a subcooling parallel section before the refrigerant inlet of the electronic expansion valve in the indoor unit of a multi-split air conditioner, and a subcooling branch set in parallel with the subcooling parallel section, the refrigerant flow in the main flow of the indoor unit can be partially or completely passed through the subcooling branch before entering the refrigerant inlet of the electronic expansion valve by switching the connecting components. This increases the subcooling degree before the electronic expansion valve, thereby making the refrigerant more stable during the throttling process, and thus achieving the purpose of improving the throttling noise on the indoor side of the multi-split air conditioner.

[0088] Figure 5 This is a flowchart illustrating a method for controlling a multi-split air conditioner according to an embodiment of this disclosure, applied to... Figure 2 The method described is applicable to multi-split air conditioners. It can be executed by the processor of the multi-split air conditioner, or by a cloud server communicating with the multi-split air conditioner; it can also be executed at the control terminal of the multi-split air conditioner. In this embodiment, the processor of the multi-split air conditioner is used as the execution entity to illustrate the solution.

[0089] Combination Figure 5As shown, the method for controlling a multi-split air conditioner includes:

[0090] Step S501: In response to the cooling mode operation command, obtain the current first subcooling degree at the cooling liquid inlet end of the electronic expansion valve.

[0091] The current first subcooling degree refers to the current subcooling degree of the electronic expansion valve when the refrigerant enters the electronic expansion valve after passing through the cold parallel section.

[0092] Generally, during cooling mode operation, the subcooling parallel section of the indoor unit is connected to the electronic expansion valve, while the subcooling branch is disconnected from the electronic expansion valve. The refrigerant flows through the main flow path via the subcooling parallel section into the electronic expansion valve for throttling. That is, the first solenoid valve is on, and the second solenoid valve is off.

[0093] Step S502: When the current first subcooling degree is less than or equal to the first preset subcooling degree, control the switching connection component to connect the subcooling branch with the electronic expansion valve.

[0094] The first preset subcooling degree n1 is used to indicate that the current subcooling degree is too small, and there will be noise problems when the refrigerant flows through the electronic expansion valve, so the subcooling degree needs to be increased.

[0095] At the current first supercooling degree SC j1 When n is less than or equal to n1, it indicates that the subcooling degree before the electronic expansion valve is too low, which may cause abnormal throttling noise. Therefore, by connecting the subcooling branch to the electronic expansion valve, some or all of the refrigerant enters the electronic expansion valve after passing through the subcooling branch for throttling. Since the subcooling branch increases the subcooling degree of this part or all of the refrigerant, it adjusts the subcooling degree before the electronic expansion valve, thereby improving the problem of abnormal throttling noise.

[0096] Here, controlling the switching connection component to connect the subcooling branch to the electronic expansion valve can include two scenarios: either only the subcooling branch is connected to the electronic expansion valve, while the subcooling parallel section is disconnected from the electronic expansion valve, in which case all refrigerant passes through the subcooling branch before entering the electronic expansion valve; or both the subcooling branch and the subcooling parallel section are connected to the electronic expansion valve, in which case a portion enters the subcooling parallel section and a portion enters the subcooling branch for subcooling adjustment; then both refrigerant lines are input into the electronic expansion valve for throttling.

[0097] Optionally, according to SC j1 The absolute value of the difference between n1 and n1 satisfies the difference range, which controls the connection state of the switching connection component.

[0098] Specifically, in SC j1 When the absolute value of the difference with n1 is greater than the first difference, the connection state of the control switching component is set so that only the subcooling branch is connected to the electronic expansion valve, and the subcooling parallel section is disconnected from the electronic expansion valve, in order to significantly increase the subcooling degree of the refrigerant; in SCj1 When the absolute value of the difference with n1 is less than the first difference, the connection state of the control switching connection component is such that both the subcooled branch and the subcooled parallel section are connected to the electronic expansion valve. At this time, the problem of abnormal noise of throttling is improved by adjusting the subcooling degree of part of the refrigerant.

[0099] Furthermore, in SC j1 When the absolute value of the difference with n1 is less than the first difference, it can also be determined based on SC. j1 The absolute value of the difference between SC and n1 satisfies the proportional adjustment range, which adjusts the proportion of refrigerant entering the subcooled branch and the subcooled parallel section. SC can be obtained experimentally. j1 The relationship between the absolute value of the difference from n1 and the refrigerant adjustment ratio range is established. After obtaining the absolute value of the current difference, the current ratio adjustment range corresponding to the absolute value of the current difference can be obtained by querying the database. Therefore, the ratio of refrigerant entering the subcooled branch and the subcooled parallel section can be adjusted according to the current ratio adjustment range. The adjustment of the refrigerant ratio entering the subcooled branch and the subcooled parallel section can be achieved by adjusting the opening degree of the connecting device.

[0100] Optionally, the current subcooling at the refrigerant inlet of the electronic expansion valve is obtained, including:

[0101] The current first subcooling degree is determined based on the difference between the current condensing temperature of the outdoor unit and the first refrigerant temperature at the refrigerant inlet of the electronic expansion valve.

[0102] Here, the current condensing temperature can be obtained by converting the current refrigerant pressure at the outdoor unit's condenser outlet according to the relationship between temperature and saturation pressure, thus obtaining the current condensing temperature TC of the outdoor unit.

[0103] Optionally, the subcooling degree may decrease due to pipe friction loss and heat loss as the refrigerant flows through the piping. Therefore, it is necessary to correct the current refrigerant pressure using subcooling correction parameters.

[0104] Therefore, the current first degree of subcooling can be obtained in the following way:

[0105] SC j1 =k×TC-T 1,j1

[0106] Among them, SC j1 The current first subcooling, TC is the current condensation temperature, and T is the current condensation temperature. 1,j1 The temperature of the first refrigerant is k, and k is the subcooling correction parameter: k < 1.

[0107] Figure 6 This is a flowchart illustrating a method for controlling a multi-split air conditioner according to an embodiment of this disclosure, applied to... Figure 2The illustrated multi-split air conditioner includes an indoor unit comprising a main air duct and a subcooling air duct. This method can be executed by the processor of the multi-split air conditioner, or by a cloud server communicating with the multi-split air conditioner; it can also be executed at the control terminal of the multi-split air conditioner. In this embodiment, the processor of the multi-split air conditioner is used as the execution entity to describe the solution.

[0108] Combination Figure 6 As shown, the method for controlling a multi-split air conditioner includes:

[0109] Step S601: In response to the cooling mode operation command, obtain the current first subcooling degree at the cooling liquid inlet end of the electronic expansion valve.

[0110] Step S602: When the current first subcooling degree is less than or equal to the first preset subcooling degree, control the switching connection component to connect the subcooling branch with the electronic expansion valve.

[0111] Step S603: Obtain the second refrigerant temperature at the outlet of the subcooled branch.

[0112] Step S604: Determine the current second subcooling degree at the refrigerant inlet of the electronic expansion valve based on the difference between the current condensing temperature of the outdoor unit and the second refrigerant temperature.

[0113] Step S605: Control the airflow from the main air duct to the subcooling duct according to the preset subcooling range satisfied by the current second subcooling.

[0114] Here, by controlling the airflow from the main air duct to the subcooling air duct, the airflow in the subcooling air duct exchanges heat with the subcooler, thereby increasing the subcooling of the refrigerant in the subcooler.

[0115] The second refrigerant temperature can be the refrigerant temperature at the outlet of the subcooler in the subcooled branch, or it can be the refrigerant temperature at the outlet of the pipe in the subcooled branch.

[0116] The current second subcooling refers to the current subcooling of the electronic expansion valve when some or all of the refrigerant has passed through the cold branch and entered the electronic expansion valve.

[0117] Furthermore, the current second degree of subcooling can be obtained in the following way:

[0118] SC j2 =k×TC-T l,j2

[0119] Among them, SC j2 The current second subcooling, TC is the current condensation temperature, and T is the current condensation temperature. 1,j2 The temperature of the second refrigerant is k, which is the subcooling correction parameter: k < 1.

[0120] Optionally, based on the preset subcooling range satisfied by the current second subcooling, the airflow from the main air duct to the subcooling air duct is controlled, including:

[0121] If the current second subcooling degree is less than or equal to the first preset subcooling degree, the airflow from the main air duct to the subcooling air duct is increased.

[0122] If the current second subcooling degree is greater than the second preset subcooling degree, the airflow from the main air duct to the subcooling air duct will be reduced.

[0123] If the current second subcooling degree is greater than the first preset subcooling degree, but less than or equal to the second preset subcooling degree, the airflow from the main air duct to the subcooling air duct remains unchanged.

[0124] Here, the airflow from the main air duct to the subcooling duct is adjusted according to the different preset subcooling ranges satisfied by the current second subcooling, so that the second subcooling is kept within a suitable range, and no obvious throttling noise will occur when throttling.

[0125] The second preset subcooling degree n2 is used to indicate a situation where the current subcooling degree is too high, and there will be noise problems when the refrigerant flows through the electronic expansion valve, so the subcooling degree needs to be reduced.

[0126] That is, by controlling the airflow from the main air duct to the subcooled air duct, the second subcooling degree is maintained within the range of (n1, n2] (i.e., the suitable subcooling degree range), so as to improve the throttling noise.

[0127] The value of the suitable subcooling range is determined based on the ambient temperature parameters and / or the electronic expansion valve diameter parameters. Ambient temperature parameters include both outdoor and indoor ambient temperatures. For example, the larger the diameter parameter of the electronic expansion valve, the smaller the lower and upper limits of the suitable subcooling range. Optionally, the correspondence between the ambient temperature parameters, the electronic expansion valve diameter parameters, and the suitable subcooling range can be obtained experimentally. After obtaining the current ambient temperature parameters and / or the electronic expansion valve diameter parameters, the current suitable subcooling range corresponding to the current ambient temperature parameters and / or the electronic expansion valve diameter parameters can be obtained by querying a database. Therefore, based on the numerical relationship between the current second subcooling and the current suitable subcooling range, the airflow from the main air duct to the subcooling duct can be controlled.

[0128] Optionally, after controlling the airflow from the main air duct to the subcooled air duct, the method further includes:

[0129] The second refrigerant temperature and condensation temperature at the outlet of the subcooled branch are obtained at preset intervals.

[0130] That is, a preset duration is used as the adjustment time period to adjust the airflow into the subcooling duct at intervals when the main air duct and the subcooling air duct are connected, so that the subcooling degree before the valve, determined according to the second refrigerant temperature and the condensing temperature, is maintained within the appropriate subcooling degree range.

[0131] Furthermore, the airflow from the main air duct to the subcooled air duct is adjusted by regulating the opening of the damper installed on the subcooled air duct.

[0132] Combination Figure 4 Increasing the airflow from the main air duct to the subcooled air duct can include controlling a stepper motor to drive the damper to rotate in the direction of increasing the opening.

[0133] Furthermore, controlling the stepper motor to drive the damper to rotate in the direction of increasing opening can include:

[0134] Obtain SC j2 The current subcooling difference between n1 and n1 is used to determine the corresponding current opening adjustment value based on the difference range that the current subcooling difference satisfies.

[0135] Based on the correspondence between the opening adjustment value and the stepper motor step count, determine the current drive step count of the stepper motor;

[0136] Control the stepper motor to run according to the current number of drive steps, so as to control the damper to rotate according to the current opening adjustment value.

[0137] In this way, it is possible to achieve according to SC j2 The damper rotation value is controlled in real time to ensure that the airflow from the main air duct to the subcooling air duct meets the requirements for increasing the subcooling degree.

[0138] Similarly, further, controlling the stepper motor to drive the damper to rotate in the direction of decreasing opening can include:

[0139] Obtain SC j2 The current subcooling difference between n2 and n2 is used to determine the corresponding current opening adjustment value based on the difference range that the current subcooling difference satisfies.

[0140] Based on the correspondence between the opening adjustment value and the stepper motor step count, determine the current drive step count of the stepper motor;

[0141] Control the stepper motor to run according to the current number of drive steps, so as to control the damper to rotate according to the current opening adjustment value.

[0142] In this way, it is possible to achieve according to SC j2 By controlling the damper rotation value in real time, the airflow entering the subcooled air duct is reduced, thereby preventing excessive subcooling.

[0143] Figure 7This is a flowchart illustrating a method for controlling a multi-split air conditioner according to an embodiment of this disclosure, applied to... Figure 2 The multi-split air conditioner is shown. This method can be executed by the processor of the multi-split air conditioner, or by a cloud server communicating with the multi-split air conditioner; it can also be executed at the control terminal of the multi-split air conditioner. In this embodiment, the processor of the multi-split air conditioner is used as the execution entity to describe the solution.

[0144] Combination Figure 7 As shown, the method for controlling a multi-split air conditioner includes:

[0145] Step S701: In response to the cooling mode operation command, obtain the outdoor ambient temperature.

[0146] Step S702: When the outdoor ambient temperature is greater than the preset temperature, obtain the current first subcooling degree at the refrigerant inlet of the electronic expansion valve.

[0147] Step S703: When the current first subcooling degree is less than or equal to the first preset subcooling degree, control the switching connection component to connect the subcooling branch with the electronic expansion valve.

[0148] Step S704: Obtain the outdoor ambient temperature at intervals.

[0149] Step S705: When the outdoor ambient temperature is less than or equal to the preset temperature, control the switching connection component to disconnect the subcooling branch from the electronic expansion valve; and when the current first subcooling degree is greater than the first preset subcooling degree, control the switching connection component to disconnect the subcooling branch from the electronic expansion valve, or maintain the switching connection component to disconnect the subcooling branch from the electronic expansion valve.

[0150] An outdoor ambient temperature higher than the preset temperature indicates that the high outdoor ambient temperature may affect the temperature of the refrigerant flowing from the outdoor unit to the indoor unit, potentially leading to insufficient subcooling before the valve. The preset temperature can be between 26℃ and 30℃, for example, 26℃, 27℃, 28℃, 29℃, or 30℃. In this embodiment, the preset temperature is set to 27℃.

[0151] When the outdoor ambient temperature is higher than the preset temperature, the subcooling acquisition operation before the valve is triggered. Then, by comparing the current first subcooling at the refrigerant inlet of the electronic expansion valve with the first preset subcooling, it is determined whether it is necessary to increase the subcooling before the valve by connecting the refrigerant branch, so as to improve the throttling noise.

[0152] When the outdoor ambient temperature is less than or equal to the preset temperature, it is assumed that the outdoor ambient temperature has little impact on the refrigerant temperature in the piping from the outdoor unit to the indoor unit, reducing the likelihood of insufficient subcooling before the valve. In this case, the connection between the subcooling branch and the electronic expansion valve is disconnected, allowing the refrigerant to directly enter the electronic expansion valve through the main flow path.

[0153] Thus, by setting a subcooling parallel section before the refrigerant inlet of the electronic expansion valve in the indoor unit of a multi-split air conditioner, and a subcooling branch connected in parallel with the subcooling parallel section, the subcooling degree before the electronic expansion valve is obtained when the outdoor ambient temperature is higher than the preset temperature. If the subcooling degree before the valve is insufficient, the switching connection component is controlled to ensure that part or all of the refrigerant flow in the main flow path of the indoor unit passes through the subcooling branch before entering the refrigerant inlet of the electronic expansion valve, thereby increasing the subcooling degree before the electronic expansion valve and making the refrigerant more stable during the throttling process. When the outdoor ambient temperature is lower than or equal to the preset temperature, the refrigerant circulation in the main flow path is restored. Applying the control method for controlling a multi-split air conditioner provided in this embodiment can achieve the purpose of improving the throttling noise on the indoor side of the multi-split air conditioner.

[0154] Figure 8 This is a schematic diagram of a device for controlling a multi-split air conditioner, provided in an embodiment of this application. The device for controlling the multi-split air conditioner can be implemented through software, hardware, or a combination of both.

[0155] Combination Figure 8 As shown, this embodiment of the present disclosure provides an apparatus for controlling a multi-split air conditioner, including an acquisition module 81 and a control module 82; the acquisition module 81 is configured to acquire the current first subcooling degree of the refrigerant inlet end of the electronic expansion valve in response to a cooling mode operation command; the control module 82 is configured to control the switching connection component to connect the subcooling branch to the electronic expansion valve when the current first subcooling degree is less than or equal to a first preset subcooling degree.

[0156] Figure 9 This is a schematic diagram of a device for controlling a multi-split air conditioner, provided in an embodiment of this application. (In conjunction with...) Figure 9 As shown, the device for controlling a multi-split air conditioner includes:

[0157] The device includes a processor 90 and a memory 91. Optionally, it may further include a communication interface 92 and a bus 93. The processor 90, communication interface 92, and memory 91 can communicate with each other via the bus 93. The communication interface 92 can be used for information transmission. The processor 90 can call logical instructions stored in the memory 91 to execute the method for controlling a multi-split air conditioner described in the above embodiment.

[0158] Furthermore, the logic instructions in the aforementioned memory 91 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0159] The memory 91, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 90 executes functional applications and data processing by running the program instructions / modules stored in the memory 91, thereby implementing the method for controlling multi-split air conditioners in the above embodiments.

[0160] The memory 91 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 91 may include high-speed random access memory and may also include non-volatile memory.

[0161] This disclosure provides a multi-split air conditioner, including the above-described device for controlling the multi-split air conditioner.

[0162] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to perform the above-described method for controlling a multi-split air conditioner.

[0163] This disclosure provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions that, when executed by a computer, cause the computer to perform the above-described method for controlling a multi-split air conditioner.

[0164] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0165] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code; it can also be a transient storage medium.

[0166] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0167] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0168] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed units may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0169] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A multi-split air conditioner, comprising: An outdoor unit and an indoor unit, wherein the indoor unit comprises multiple indoor units connected in parallel; characterized in that at least one indoor unit comprises: The main pipeline includes an electronic expansion valve and an indoor heat exchanger connected in sequence via a main pipeline; wherein at least a portion of the main pipeline located at the refrigerant inlet end of the electronic expansion valve is used as a subcooled parallel section. The subcooling branch includes a subcooler; the subcooling branch is connected in parallel with the subcooling parallel section; the subcooler is located in the air field area on the air outlet side of the indoor heat exchanger. The switching connection component is configured to controllably connect the subcooled parallel section and / or the subcooled branch to the electronic expansion valve; The main air duct is equipped with the aforementioned indoor heat exchanger; The subcooling duct is located downstream of the main air duct and connected in parallel with the main air duct. The subcooler is located inside the subcooling duct. The air inlet of the subcooling duct is also provided with a damper, which is configured to controllably adjust its opening to change the airflow from the main air duct to the subcooling duct.

2. The multi-split air conditioner according to claim 1, characterized in that, The switching connectivity component includes: A first solenoid valve is installed in the subcooled parallel section; The second solenoid valve is located in the subcooled branch.

3. A method for controlling a multi-split air conditioner as described in claim 1 or 2, characterized in that, include: In response to the cooling mode operation command, the current first subcooling degree of the cooling liquid inlet of the electronic expansion valve is obtained; When the current first subcooling degree is less than or equal to the first preset subcooling degree, the control switches the connection component to connect the subcooling branch to the electronic expansion valve.

4. The method according to claim 3, characterized in that, The step of obtaining the current first subcooling at the refrigerant inlet of the electronic expansion valve includes: The current first subcooling is determined based on the difference between the current condensing temperature of the outdoor unit and the first refrigerant temperature at the refrigerant inlet of the electronic expansion valve.

5. The method according to claim 4, characterized in that, The current first subcooling is obtained in the following manner: Among them, SC j1 The current first subcooling, TC is the current condensation temperature, and T is the current condensation temperature. 1,j1 The temperature of the first refrigerant is k, and k is the subcooling correction parameter: k < 1.

6. The method according to claim 3, characterized in that, The control switching connection assembly to connect the subcooled branch to the electronic expansion valve includes: The control switching connection component connects the subcooled branch to the electronic expansion valve, and disconnects the subcooled parallel section from the electronic expansion valve; or, The control switching connection component connects both the subcooled branch and the subcooled parallel section to the electronic expansion valve.

7. The method according to claim 3, characterized in that, If the indoor unit includes a main air duct and a subcooling air duct, then after connecting the subcooling branch to the electronic expansion valve, the method further includes: Obtain the second refrigerant temperature at the outlet end of the subcooled branch; The current second subcooling degree at the refrigerant inlet of the electronic expansion valve is determined based on the difference between the current condensing temperature of the outdoor unit and the temperature of the second refrigerant. Based on the preset subcooling range satisfied by the current second subcooling, the airflow from the main air duct to the subcooling air duct is controlled.

8. The method according to claim 7, wherein the current second subcooling is obtained in the following manner: in, SC j2 The current second subcooling, TC is the current condensation temperature, and T is the current condensation temperature. 1,j2 The temperature of the second refrigerant is k, which is the subcooling correction parameter: k < 1.

9. The method according to claim 7, characterized in that, If the current second subcooling degree is less than or equal to the first preset subcooling degree, the airflow from the main air duct to the subcooling air duct is increased. If the current second subcooling degree is greater than the second preset subcooling degree, the airflow from the main air duct to the subcooling air duct is reduced. If the current second subcooling degree is greater than the first preset subcooling degree and less than or equal to the second preset subcooling degree, the airflow from the main air duct to the subcooling air duct is kept constant.

10. The method according to claim 9, characterized in that, If the subcooling duct is equipped with a damper, the opening can be controlled to change the airflow from the main duct to the subcooling duct. The control of increasing the airflow from the main air duct to the subcooled air duct includes: Based on the difference between the current second subcooling degree and the first preset subcooling degree, the damper is controlled to rotate in the direction of increasing the opening degree, so as to increase the airflow from the main air duct to the subcooling air duct; Controlling the reduction of airflow from the main air duct to the subcooled air duct includes: Based on the difference between the current second subcooling degree and the second preset subcooling degree, the damper is controlled to rotate in the direction of decreasing opening, so as to reduce the airflow from the main air duct to the subcooling air duct.

11. The method according to any one of claims 3 to 10, characterized in that, When the outdoor ambient temperature is higher than the preset temperature, the current first subcooling degree of the refrigerant inlet of the electronic expansion valve is obtained; When the outdoor ambient temperature is less than or equal to the preset temperature, the switching connection component is controlled to disconnect the subcooled branch from the electronic expansion valve.

12. An apparatus for controlling a multi-split air conditioner as described in claim 1 or 2, characterized in that, include: The acquisition module is configured to acquire the current first subcooling at the refrigerant inlet of the electronic expansion valve in response to a cooling mode operation command. The control module is configured to control the switching connection component to connect the subcooling branch to the electronic expansion valve when the current first subcooling degree is less than or equal to the first preset subcooling degree.

13. An apparatus for controlling a multi-split air conditioner as described in claim 1 or 2, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to, when executing the program instructions, perform the method for controlling a multi-split air conditioner as described in any one of claims 3 to 11.

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