A control method and device of an air conditioner, the air conditioner and a storage medium

Abstract

The application discloses a control method and device of an air conditioner, the air conditioner and a storage medium, wherein the indoor heat exchanger of the air conditioner has n branches with n-in-n-out, the control method comprises the following steps: preliminarily determining whether the indoor heat exchanger has appeared refrigerant uneven distribution according to the total temperature difference of the indoor heat exchanger and the branch temperature difference of the n branches; if it is preliminarily determined that the refrigerant uneven distribution appears, further determining whether the indoor heat exchanger has appeared the refrigerant uneven distribution according to the outlet temperature difference of the n branches and the inlet temperature difference of the n branches; if it is further determined that the refrigerant uneven distribution appears, determining and sending the fault position, and controlling the compressor of the air conditioner to operate at a reduced frequency according to the branch temperature difference of the n branches. According to the scheme, the temperature of the total inlet and the total outlet of the indoor heat exchanger and the temperature of the inlet and the outlet of each branch are combined, the fault position is determined when the refrigerant uneven distribution appears, the compressor is controlled to operate at a reduced frequency, and the reliability of the indoor unit control is improved.

Description

Technical Field

[0001] This invention belongs to the field of air conditioner technology, specifically relating to an air conditioner control method, device, air conditioner, and storage medium, and particularly to a method, device, air conditioner, and storage medium for improving the reliability of an air conditioner indoor unit. Background Technology

[0002] As a key component of air conditioners, heat exchangers facilitate heat transfer between fluids at different temperatures. Among these, the evaporator, as a type of heat exchanger, is the component that directly generates cooling capacity. Improvements to the evaporator play a crucial role in enhancing the energy efficiency of air conditioners and possess significant energy-saving potential.

[0003] Accurate temperature detection within the evaporator plays a crucial role in the overall control of the air conditioner. However, in related solutions, the air conditioner often uses temperature compensation for temperature correction in the control of the indoor unit. But temperature correction is based on experience or experimental data, and inaccurate temperature correction affects the reliability of indoor unit control.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, air conditioner, and storage medium for an air conditioner, to solve the problem that in the control of the indoor unit of an air conditioner, the air conditioner often uses temperature compensation for temperature correction. However, the temperature correction is based on experience or experimental data, and the inaccuracy of the temperature correction affects the reliability of the indoor unit control. The invention achieves the goal of judging the refrigerant distribution uniformity of the indoor heat exchanger by combining the temperatures of the total inlet and outlet of the indoor heat exchanger, as well as the inlet and outlet temperatures of each branch circuit. When uneven refrigerant distribution occurs, the fault location is identified and an alert is issued, and the compressor is controlled to operate at a reduced frequency, which helps to improve the reliability of the indoor unit control.

[0006] This invention provides a control method for an air conditioner, wherein the air conditioner has an indoor heat exchanger; the indoor heat exchanger has n inlets and n outlets, where n is a positive integer greater than or equal to 2; the total inlet of the indoor heat exchanger is connected to the n inlets of the n branches, and the n outlets of the n branches are connected to the total outlet of the indoor heat exchanger; the control method for the air conditioner includes: after the air conditioner is turned on, determining the current operating mode of the air conditioner, determining the current fan speed of the indoor fan, and determining the current airflow direction of the indoor unit. Plate position; after the air conditioner has been running for a first set time in its current operating mode, at the current fan speed of the indoor unit, and at the current air guide plate position of the indoor unit, the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches are obtained; the temperature difference between the total inlet temperature and the total outlet temperature of the indoor heat exchanger is determined and recorded as the total temperature difference of the indoor heat exchanger; the temperature difference between each of the n branches is determined. The temperature difference between the inlet temperature and the outlet temperature of each branch is used to obtain the temperature difference of the n branches, which is denoted as the branch temperature difference of the n branches; the temperature difference between the maximum and minimum outlet temperatures of the n branches is determined and denoted as the outlet temperature difference of the n branches; and the temperature difference between the maximum and minimum inlet temperatures of the n branches is determined and denoted as the inlet temperature difference of the n branches; based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches, it is preliminarily determined whether the indoor heat exchanger has experienced uneven refrigerant distribution; if If it is initially determined that the indoor heat exchanger has an uneven refrigerant distribution, then based on the outlet temperature difference and inlet temperature difference of the n branches, and combined with the branch temperature difference of the n branches, it is further determined whether the indoor heat exchanger has an uneven refrigerant distribution. If it is further determined that the indoor heat exchanger has an uneven refrigerant distribution, then the fault location of the uneven refrigerant distribution is determined, and an alert message for the fault location is initiated. Furthermore, based on the branch temperature difference of the n branches, the compressor of the air conditioner is controlled to operate at a reduced frequency.

[0007] In some embodiments, the current operating mode of the air conditioner is either cooling mode or heating mode; and / or, the current fan speed of the indoor fan is any one of the preset high speed, preset high speed, preset medium speed, preset low speed, and preset silent speed; and / or, the indoor unit has a first air guide plate and a second air guide plate; the current air guide plate position of the indoor unit is any one of the following combinations: the default combination position of the first air guide plate and the second air guide plate, the first combination position of the first air guide plate and the second air guide plate, the second combination position of the first air guide plate and the second air guide plate, the third combination position of the first air guide plate and the second air guide plate, and the fourth combination position of the first air guide plate and the second air guide plate.

[0008] In some embodiments, based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches, a preliminary determination is made as to whether the indoor heat exchanger has experienced uneven refrigerant distribution. This includes: determining the current total temperature difference threshold of the indoor heat exchanger based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set total temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and determining the current total temperature difference threshold of the indoor heat exchanger based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set branch temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and determining the current total temperature difference threshold of the indoor heat exchanger based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set branch temperature difference threshold, under the current operating mode of the air conditioner, the current total temperature difference threshold of the indoor heat exchanger. Under the following conditions: operating mode, current fan speed of the indoor fan, and current air guide plate position of the indoor unit, determine the current branch temperature difference threshold of the n branches; determine whether the total temperature difference of the indoor heat exchanger is less than the current total temperature difference threshold of the indoor heat exchanger: if so, it is preliminarily determined that the indoor heat exchanger has experienced uneven refrigerant distribution; determine whether the branch temperature difference of each of the n branches is less than the current branch temperature difference threshold of the n branches: if so, it is preliminarily determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is preliminarily determined that the branch has a weld blockage, and a reminder message indicating that the branch has a weld blockage is issued.

[0009] In some implementations, based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in conjunction with the branch temperature difference of the n branches, it is further determined whether the indoor heat exchanger has experienced uneven refrigerant distribution. This includes: determining the current outlet temperature difference threshold of the indoor heat exchanger under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, based on the correspondence between the set operating mode, the set fan speed, the set air guide plate position, and the set outlet temperature difference threshold; and determining the current inlet temperature difference threshold of the indoor heat exchanger under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, based on the correspondence between the set operating mode, the set fan speed, the set air guide plate position, and the set inlet temperature difference threshold; and determining the outlet temperature difference of the n branches. If the temperature difference is greater than the current outlet temperature difference threshold of the indoor heat exchanger, then it is further determined that the indoor heat exchanger has experienced refrigerant uneven flow, and it is believed that the reason for the uneven refrigerant uneven flow is due to the uneven refrigerant uneven flow in the n branches; if the temperature difference at the inlet of the n branches is greater than the current inlet temperature difference threshold of the indoor heat exchanger, then it is further determined that the indoor heat exchanger has experienced refrigerant uneven flow, and it is believed that the reason for the uneven refrigerant uneven flow is due to the uneven refrigerant uneven flow caused by the distributor of the indoor heat exchanger; otherwise, it is further determined that the indoor heat exchanger has experienced refrigerant uneven flow, and it is believed that the reason for the uneven refrigerant uneven flow is due to the uneven refrigerant uneven flow in the n branches.

[0010] In some implementations, if it is further determined that the indoor heat exchanger has experienced refrigerant uneven distribution, then the fault location of the refrigerant uneven distribution in the indoor heat exchanger is determined, and an alert message for the fault location is initiated. This includes: if it is further determined that the indoor heat exchanger has experienced refrigerant uneven distribution, and it is believed that the cause of the refrigerant uneven distribution in the indoor heat exchanger is due to uneven distribution of refrigerant in the distributor of the indoor heat exchanger, then it is determined that the indoor heat exchanger has experienced refrigerant uneven distribution. The fault location for the uneven refrigerant distribution is the distributor, and an alert message for uneven refrigerant distribution is sent to the distributor. If it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the cause of the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution in the n branches, then the maximum value among the branch temperature differences of the n branches is determined, and the branch corresponding to the maximum value is locked as the branch with uneven refrigerant distribution, and an alert message for uneven refrigerant distribution in that branch is sent.

[0011] In some implementations, controlling the air conditioner's compressor to operate at a reduced frequency based on the branch temperature differences of the n branches includes: determining the minimum value among the branch temperature differences of the n branches; determining the target frequency of the air conditioner's compressor based on the inlet and outlet temperatures of the branch corresponding to the minimum value; reducing the compressor's current frequency to the target frequency at a set reduction rate to correct the compressor's current frequency and cause it to operate at a reduced frequency; continuing to correct the compressor's current frequency after a second set time to cause it to operate at a reduced frequency; repeating this process until the compressor's current frequency is reduced to a preset minimum frequency; controlling the air conditioner to continue operating after a third set time; and if it is still determined that the indoor heat exchanger has uneven refrigerant distribution, then controlling the air conditioner to shut down.

[0012] In conjunction with the above method, another aspect of the present invention provides a control device for an air conditioner, wherein the air conditioner has an indoor heat exchanger; the indoor heat exchanger has n branches with n inlets and n outlets, where n is a positive integer greater than or equal to 2; the total inlet of the indoor heat exchanger is connected to the n inlets of the n branches, and the n outlets of the n branches are connected to the total outlet of the indoor heat exchanger; the control device for the air conditioner includes: a control unit configured to, after the air conditioner is turned on, determine the current operating mode of the air conditioner, determine the current fan speed of the indoor fan of the air conditioner, and determine the current fan speed of the indoor unit of the air conditioner. The front air guide vane position; the acquisition unit is configured to, after the air conditioner has been running for a first set time in the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide vane position of the indoor unit, acquire the total inlet temperature of the indoor heat exchanger, acquire the total outlet temperature of the indoor heat exchanger, acquire the inlet temperature of each of the n branches, and acquire the outlet temperature of each of the n branches; the control unit is further configured to determine the temperature difference between the total inlet temperature of the indoor heat exchanger and the total outlet temperature of the indoor heat exchanger, denoted as the total temperature difference of the indoor heat exchanger; determine the n branches The temperature difference between the inlet temperature and the outlet temperature of each branch in the circuit is used to obtain the temperature difference of the n branches, which is denoted as the branch temperature difference of the n branches; the temperature difference between the maximum and minimum outlet temperatures of the n branches is determined and denoted as the outlet temperature difference of the n branches; and the temperature difference between the maximum and minimum inlet temperatures of the n branches is determined and denoted as the inlet temperature difference of the n branches; the control unit is further configured to preliminarily determine whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches; the control unit... The unit is further configured to, if it is initially determined that the indoor heat exchanger has experienced refrigerant uneven distribution, further determine whether the indoor heat exchanger has experienced refrigerant uneven distribution based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in combination with the branch temperature difference of the n branches; the control unit is further configured to, if it is further determined that the indoor heat exchanger has experienced refrigerant uneven distribution, determine the fault location of the indoor heat exchanger experiencing refrigerant uneven distribution, initiate a reminder message for the fault location; and, based on the branch temperature difference of the n branches, control the compressor of the air conditioner to operate at a reduced frequency.

[0013] In some embodiments, the current operating mode of the air conditioner is either cooling mode or heating mode; and / or, the current fan speed of the indoor fan is any one of the preset high speed, preset high speed, preset medium speed, preset low speed, and preset silent speed; and / or, the indoor unit has a first air guide plate and a second air guide plate; the current air guide plate position of the indoor unit is any one of the following combinations: the default combination position of the first air guide plate and the second air guide plate, the first combination position of the first air guide plate and the second air guide plate, the second combination position of the first air guide plate and the second air guide plate, the third combination position of the first air guide plate and the second air guide plate, and the fourth combination position of the first air guide plate and the second air guide plate.

[0014] In some embodiments, the control unit, based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches, initially determines whether the indoor heat exchanger has experienced uneven refrigerant distribution, including: determining the current total temperature difference threshold of the indoor heat exchanger according to the correspondence between the set operating mode, set fan speed, set air guide plate position, and set total temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and determining the current total temperature difference threshold of the indoor heat exchanger according to the correspondence between the set operating mode, set fan speed, set air guide plate position, and set branch .... Under the current operating mode, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, determine the current branch temperature difference threshold of the n branches; determine whether the total temperature difference of the indoor heat exchanger is less than the current total temperature difference threshold of the indoor heat exchanger: if so, it is preliminarily determined that the indoor heat exchanger has a refrigerant uneven distribution situation; determine whether the branch temperature difference of each of the n branches is less than the current branch temperature difference threshold of the n branches: if so, it is preliminarily determined that the indoor heat exchanger has a refrigerant uneven distribution situation, and it is preliminarily determined that the branch has a weld blockage, and a reminder message is issued that the branch has a weld blockage.

[0015] In some embodiments, the control unit further determines whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in conjunction with the branch temperature difference of the n branches. This includes: determining the current outlet temperature difference threshold of the indoor heat exchanger based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set outlet temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and determining the current inlet temperature difference threshold of the indoor heat exchanger based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set inlet temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and determining the n branches. If the outlet temperature difference is greater than the current outlet temperature difference threshold of the indoor heat exchanger, then it is further determined that the indoor heat exchanger has experienced refrigerant uneven flow, and it is believed that the reason for the uneven refrigerant flow is due to the uneven refrigerant flow in the n branches; if the inlet temperature difference of the n branches is greater than the current inlet temperature difference threshold of the indoor heat exchanger, then it is further determined that the indoor heat exchanger has experienced refrigerant uneven flow, and it is believed that the reason for the uneven refrigerant flow is due to the uneven refrigerant flow caused by the distributor of the indoor heat exchanger; otherwise, it is further determined that the indoor heat exchanger has experienced refrigerant uneven flow, and it is believed that the reason for the uneven refrigerant flow is due to the uneven refrigerant flow in the n branches.

[0016] In some implementations, if the control unit further determines that the indoor heat exchanger has experienced refrigerant uneven distribution, it determines the fault location of the refrigerant uneven distribution in the indoor heat exchanger and initiates a fault location alert message, including: if it further determines that the indoor heat exchanger has experienced refrigerant uneven distribution, and it is believed that the cause of the refrigerant uneven distribution in the indoor heat exchanger is due to uneven distribution of refrigerant in the distributor of the indoor heat exchanger, then it determines that the indoor heat exchanger has experienced refrigerant uneven distribution. The fault location where the refrigerant distribution is uneven is the distributor, and an alert message for uneven refrigerant distribution is sent to the distributor. If it is further determined that the indoor heat exchanger has an uneven refrigerant distribution, and it is believed that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to the uneven refrigerant distribution in the n branches, then the maximum value of the branch temperature difference among the n branches is determined, the branch corresponding to the maximum value is locked as the branch with the uneven refrigerant distribution, and an alert message for the uneven refrigerant distribution in that branch is sent.

[0017] In some embodiments, the control unit controls the air conditioner compressor to operate at a reduced frequency based on the branch temperature difference of the n branches, including: determining the minimum value among the branch temperature differences of the n branches; determining the target frequency of the air conditioner compressor based on the inlet and outlet temperatures of the branch corresponding to the minimum value; reducing the current frequency of the compressor to the target frequency of the compressor at a set reduction rate to correct the current frequency of the compressor and make the compressor operate at a reduced frequency; after a second set time, continuing to correct the current frequency of the compressor and make the compressor operate at a reduced frequency; repeating this cycle until the current frequency of the compressor is reduced to a preset minimum frequency, and controlling the air conditioner to continue operating for a third set time. If it is still determined that there is uneven refrigerant distribution in the indoor heat exchanger, then the air conditioner is controlled to shut down.

[0018] In conjunction with the above-described device, the present invention further provides an air conditioner, comprising: the control device for the air conditioner described above.

[0019] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device on which the storage medium is located controls the air conditioner control method described above to be performed.

[0020] Therefore, the solution of this invention, for the indoor unit of an air conditioner, employs an indoor heat exchanger (such as an evaporator) with n inlets and n outlets, where the total inlet of the indoor heat exchanger is connected to the n inlets of the n branches, and the n outlets of the n branches are connected to the total outlet of the indoor heat exchanger. The n branches are arranged in parallel between the total inlet and the total outlet of the indoor heat exchanger, where n is a positive integer greater than or equal to 2. Under the current operating mode, current indoor unit fan speed, and current air guide vane position of the air conditioner... After stable operation for a certain period of time (e.g., 10 minutes), the total inlet and outlet temperatures of the indoor heat exchanger, as well as the inlet and outlet temperatures of each of the n branches of the indoor heat exchanger, are collected. The total temperature difference (e.g., ΔT) between the total inlet and outlet temperatures of the indoor heat exchanger is determined. The branch temperature difference (e.g., ΔT1, ΔT2, ΔT3, and ΔT4) between the inlet and outlet temperatures of each branch is determined to obtain the branch temperature differences of the n branches. Finally, the maximum and minimum outlet temperatures of the n branches are determined. The outlet temperature difference (e.g., ΔT5) is determined, and the inlet temperature difference between the maximum and minimum values ​​of the inlet temperatures of the n branches (e.g., ΔT6) is determined. Based on the total temperature difference (e.g., ΔT), the branch temperature differences of the n branches (e.g., ΔT1, ΔT2, ΔT3, and ΔT4), the outlet temperature difference of the n branches (e.g., ΔT5), and the inlet temperature difference of the n branches (e.g., ΔT6), it is determined whether there is uneven refrigerant distribution in the indoor heat exchanger, and whether the uneven refrigerant distribution occurs at the distributor or the inlet heat exchanger itself. A branch of the system alerts users to locations where refrigerant distribution is uneven in the indoor heat exchanger. It then determines the compressor frequency based on the minimum branch temperature difference among the n branches, causing the compressor to operate at a reduced frequency. By combining the temperatures of the total inlet and outlet of the indoor heat exchanger, as well as the inlet and outlet temperatures of each branch, the system assesses the uniformity of refrigerant distribution in the indoor heat exchanger. When uneven refrigerant distribution occurs, it identifies the fault location, issues an alert, and controls the compressor to operate at a reduced frequency, thus improving the reliability of the indoor unit control.

[0021] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating an embodiment of the control method for an air conditioner according to the present invention;

[0024] Figure 2This is a flowchart illustrating an embodiment of the method of the present invention for initially determining whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of n branches.

[0025] Figure 3 This is a schematic flowchart of an embodiment of the method of the present invention, which further determines whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the outlet temperature difference, inlet temperature difference, and branch temperature difference of n branches.

[0026] Figure 4 This is a flowchart illustrating an embodiment of the method of the present invention, which controls the compressor of an air conditioner to operate at reduced frequency based on the branch temperature difference of n branches;

[0027] Figure 5 This is a schematic diagram of the structure of an embodiment of the control device for an air conditioner according to the present invention;

[0028] Figure 6 This is a schematic diagram of the air guide plate angle of the indoor unit of a split air conditioner, specifically a structural schematic diagram of the indoor unit of a split air conditioner when the air guide plate is in different positions;

[0029] Figure 7 A flowchart illustrating an embodiment of a method for determining the temperature of the indoor unit of a split air conditioner;

[0030] Figure 8 A schematic diagram of one embodiment of a four-inlet, four-outlet evaporator;

[0031] Figure 9 This is a schematic diagram of one embodiment of a two-inlet, two-outlet evaporator.

[0032] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0033] 11-Evaporator; 12-First cross-flow fan blade; 13-Panel; 14-First position of the first air guide plate (closed state); 15-Second position of the first air guide plate (middle position); 16-Third position of the first air guide plate (maximum position); 17-First position of the second air guide plate (closed state); 18-Second position of the second air guide plate; 19-Return air grille; 21-First branch inlet; 22-Second branch inlet; 23-Third branch inlet; 24-Fourth branch inlet; 25-Fourth branch outlet; 26-Third branch outlet; 27-Second branch outlet; 28-First branch outlet; 29-Splitter; 102-Acquisition unit; 104-Control unit. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] Considering that the distributor is an important auxiliary device in the evaporator of an air conditioner, uneven liquid distribution will cause the heat exchange area of ​​the evaporator to be not fully utilized, resulting in problems such as reduced cooling capacity of the air conditioner, uneven outlet air temperature of the evaporator, and vibration of the valve core of the electronic expansion valve. Therefore, the proper selection of the distributor is of great significance for the efficient operation of the air conditioner.

[0036] In an evaporator, efficient utilization of the heat exchange area is ensured only when the uniformly mixed refrigerant is distributed equally to each branch. Ideally, the distributor should provide an equal and uniform amount of refrigerant to each branch. However, in actual operation, the refrigerant supply to each branch often differs, resulting in uneven and unequal flow of the two-phase refrigerant into each branch. While the two-phase refrigerant can be considered uniformly mixed when leaving the electronic expansion valve, it naturally separates, leading to unequal distribution of refrigerant to different branches. Branches with lower refrigerant supply enter the superheated zone earlier, where the heat transfer coefficient is significantly reduced. This means the heat exchange area in this zone cannot be fully utilized, resulting in decreased evaporator heat exchange efficiency.

[0037] Furthermore, branches with higher refrigerant supply may contain incompletely evaporated refrigerant droplets at their outlets. These droplets converge at the branch outlet, creating an unstable flashing state. The temperature sensor at the evaporator outlet detects this unstable temperature signal and transmits it to the electronic expansion valve, causing oscillation of the valve core. Additionally, uneven refrigerant distribution can lead to increased temperature differences between the evaporator outlet and the airflow, as well as frost formation on the evaporator surface.

[0038] Many factors influence the flow distribution characteristics of a distributor, including not only the type of distributor, its geometry, and installation location, but also refrigerant mass flow rate, inlet dryness, and flow pattern. A high-performance distributor can maintain good performance under various operating conditions. Therefore, accurate detection of the evaporator temperature plays a crucial role in the overall control of the air conditioner.

[0039] In addition, in the relevant solutions, air conditioners mostly use temperature compensation for temperature correction. However, temperature correction is based on experience or experimental data and is not uniform. When different users use it in different usage scenarios or different regions, the temperature correction is also inaccurate and sometimes even counterproductive. Multi-temperature sensor judgment is more accurate.

[0040] Therefore, the present invention proposes a control method for an air conditioner, specifically a method to improve the reliability of the indoor unit. By using multiple temperature sensors in the indoor unit, the risk of frost formation is significantly reduced. Simultaneously, the method enhances the assessment of each flow path in the evaporator. Thus, by strengthening the assessment of the indoor unit's temperature, the reliability of the indoor unit control is improved, reducing the risk of freezing or frost formation.

[0041] According to an embodiment of the present invention, a control method for an air conditioner is provided. The air conditioner has an outdoor unit and an indoor unit. The outdoor unit has a compressor. The indoor unit has an indoor heat exchanger, an indoor fan, and an air guide plate assembly. The indoor heat exchanger is an evaporator, the indoor fan is an indoor unit fan, and the air guide plate assembly is an assembly composed of a first air guide plate and a second air guide plate. The indoor heat exchanger has n inlets and n outlets, where n is a positive integer greater than or equal to 2. The total inlet of the indoor heat exchanger is connected to the n inlets of the n branches, and the n outlets of the n branches are connected to the total outlet of the indoor heat exchanger.

[0042] Specifically, Figure 8 This is a schematic diagram of one embodiment of a four-inlet, four-outlet evaporator. Figure 8 As shown, a first temperature sensor is installed at the main inlet of the evaporator. The main inlet of the evaporator is divided into four branch inlets by a distributor, such as the first branch inlet 21, the second branch inlet 22, the third branch inlet 23, and the fourth branch inlet 24. Each of the four branches is equipped with a temperature sensor: a second temperature sensor, a third temperature sensor, a fourth temperature sensor, and a fifth temperature sensor. Corresponding to the four branch inlets, there are four branch outlets, such as the first branch outlet 28, the second branch outlet 27, the third branch outlet 26, and the fourth branch outlet 25. Each of the four branch outlets is also equipped with a temperature sensor: a sixth temperature sensor, a seventh temperature sensor, an eighth temperature sensor, and a ninth temperature sensor. At the same time, the outlets of the four branches are collected by a gas collecting pipe and converged at the main outlet of the evaporator, where a tenth temperature sensor is installed.

[0043] Figure 8 The example shown is based on a four-inlet, four-outlet evaporator, but the solution of the present invention is also applicable to a two-inlet, two-outlet evaporator. Figure 9This is a schematic diagram of one embodiment of a two-inlet, two-outlet evaporator. Figure 9 As shown, a first temperature sensor is installed at the main inlet of the evaporator. The main inlet of the evaporator is divided into two branch inlets via a distributor 29, such as the first branch inlet 21 and the second branch inlet 22. Each branch inlet is equipped with two temperature sensors: a second temperature sensor and a third temperature sensor. Corresponding to the two branch inlets, there are two branch outlets, such as the first branch outlet 28 and the second branch outlet 27. Each branch outlet is also equipped with two temperature sensors, namely the sixth temperature sensor and the seventh temperature sensor. The outlets of the two branches are combined into the main outlet of the evaporator via a gas collecting pipe, where a tenth temperature sensor is installed.

[0044] like Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. The control method of the air conditioner may include steps S110 to S160.

[0045] In step S110, after the air conditioner is turned on, the current operating mode of the air conditioner is determined, the current fan speed of the indoor fan of the air conditioner is determined, and the current air guide plate position of the indoor unit of the air conditioner is determined.

[0046] In some implementations, the current operating mode of the air conditioner is either cooling mode or heating mode. Additionally, if the air conditioner is operating in fan-only mode, the compressor will not start, preventing problems such as large temperature differences at the evaporator outlet and frost formation on the evaporator surface due to uneven refrigerant distribution. In this case, the air conditioner can operate according to a preset program.

[0047] Specifically, Figure 7 This is a flowchart illustrating an embodiment of a method for determining the temperature of the indoor unit of a split-type air conditioner. Figure 7 In the example shown, the evaporator uses a four-inlet, four-outlet configuration (see [link]). Figure 8 (Example shown). Figure 7 As shown, the method for determining the temperature of the indoor unit of a split air conditioner includes:

[0048] Step 1: Each time the unit is turned on, determine the current operating mode of the air conditioner, i.e., determine which mode the air conditioner is currently operating in, such as cooling mode, heating mode, or fan mode, and then proceed to Step 2.

[0049] Step 2: If the air conditioner is currently in cooling mode, then proceed to step 3 in cooling mode.

[0050] In some embodiments, the current fan speed of the indoor fan is any one of the preset high speed, preset high speed, preset medium speed, preset low speed, and preset silent speed.

[0051] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner also includes: Step 3, judging which of the following levels the current indoor unit fan is in: super strong, high wind, medium wind, low wind, or silent mode. For example, if the current indoor unit fan is determined to be in medium wind mode.

[0052] In some embodiments, the indoor unit has a first air guide plate and a second air guide plate; the current air guide plate position of the indoor unit is any combination of the following: a default combination position of the first air guide plate and the second air guide plate, a first combination position of the first air guide plate and the second air guide plate, a second combination position of the first air guide plate and the second air guide plate, a third combination position of the first air guide plate and the second air guide plate, and a fourth combination position of the first air guide plate and the second air guide plate. The default combination position is such as the default position; the first combination position is such as position one; the second combination position is such as position two; the third combination position is such as position three; and the fourth combination position is such as position four.

[0053] Specifically, Figure 6 This is a schematic diagram of the air guide vane angle of the indoor unit of a split air conditioner, specifically showing the structure of the indoor unit's air guide vane in different positions. For example... Figure 6 As shown, the indoor unit of a split air conditioner includes: an evaporator 11, a first cross-flow fan blade 12, a panel 13, a first air guide plate, a second air guide plate, and a return air grille 19. Inside the panel 13 of the indoor unit, along the direction from the return air inlet to the air outlet, the return air grille 19, the evaporator 11, and the first cross-flow fan blade 12 are arranged. At the air outlet, the first air guide plate and the second air guide plate are arranged. The first air guide plate can be in a first position (i.e., the position when the first air guide plate is closed), a second position (i.e., the middle position within the rotation range of the first air guide plate in the air outlet), and a third position (i.e., the maximum opening position of the first air guide plate). The second air guide plate can be in the first position (i.e., the position when the second air guide plate is closed), and the second air guide plate can also be in the second position (i.e., the second air guide plate is in the middle position within the rotation range of the second air guide plate in the air outlet or the second air guide plate is in the position where the second air guide plate is half open).

[0054] like Figure 6As shown, the states of the first air guide plate are: the first position (closed state) 14, the second position (middle position) 15, and the third position (maximum position) 16, which respectively represent the first air guide plate being in the closed position, the middle position, and the maximum position. The states of the second air guide plate are: the first position (closed state) 17 and the second position 18, which respectively represent the second air guide plate being in the closed position and the half-open position. The angle of the first position (closed state) 14 of the first air guide plate ranges from 40° to 45°, the angle of the second position (middle position) 15 of the first air guide plate ranges from 55° to 60°, the angle of the third position (maximum position) 16 of the first air guide plate ranges from 65° to 70°, and the angle is 0° if the first air guide plate is completely closed and close to the panel; the first position (closed state) 17 of the second air guide plate indicates that it is closed and the angle is 0°, and the angle of the second position 18 of the second air guide plate ranges from 20° to 30°.

[0055] like Figure 7 As shown, the method for determining the temperature of the indoor unit of a split air conditioner further includes: in step 3, after determining the current fan speed of the indoor unit, determining which of the following positions the current combined position of the first and second air guide vanes is: the default position, position one, position two, position three, or position four. Specifically, as shown... Figure 6 As shown, the default position is a combination of the second position (middle position) 15 of the first air guide plate and the first position (closed state) 17 of the second air guide plate. Position 1 is a combination of the first position (closed state) 14 of the first air guide plate and the first position (closed state) 17 of the second air guide plate. Position 2 is a combination of the third position (maximum position) 16 of the first air guide plate and the first position (closed state) 17 of the second air guide plate. Position 3 is a combination of the second position (middle position) 15 of the first air guide plate and the second position 18 of the second air guide plate. Position 4 is a combination of the third position (maximum position) 16 of the first air guide plate and the second position 18 of the second air guide plate. To prevent users from frequently switching the indoor unit fan speed and air guide plate position after powering on, only after the air conditioner mode, indoor fan speed, and air guide plate position remain unchanged, and the temperature difference is checked after 10 minutes, i.e., step 4 is executed.

[0056] In step S120, after the air conditioner has been running for a first set time in its current operating mode, at the current fan speed of the indoor unit, and at the current air guide vane position of the indoor unit, the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches are obtained. The first set time is, for example, 10 minutes.

[0057] In step S130, the temperature difference between the total inlet temperature and the total outlet temperature of the indoor heat exchanger is determined and denoted as the total temperature difference of the indoor heat exchanger, such as temperature difference ΔT; the temperature difference between the inlet temperature and the outlet temperature of each of the n branches is determined, and the temperature difference of the n branches is obtained, denoted as the branch temperature difference of the n branches, such as temperature difference ΔT1, temperature difference ΔT2, temperature difference ΔT3 and temperature difference ΔT4; the temperature difference between the maximum and minimum outlet temperatures of the n branches is determined and denoted as the outlet temperature difference of the n branches, such as temperature difference ΔT5; and the temperature difference between the maximum and minimum inlet temperatures of the n branches is determined and denoted as the inlet temperature difference of the n branches, such as temperature difference ΔT6.

[0058] Specifically, see Figure 8 and Figure 9The example shown is as follows: The temperature difference between the first temperature sensor value at the main inlet of the evaporator and the tenth temperature sensor value at the main outlet of the evaporator is ΔT; the temperature difference ΔT1 is calculated by comparing the temperature difference between the second temperature sensor value at the inlet 21 of the first branch outlet of the evaporator and the sixth temperature sensor value at the outlet 28 of the first branch outlet of the evaporator; the temperature difference ΔT2 is calculated by comparing the temperature difference between the third temperature sensor value at the inlet 22 of the second branch outlet of the evaporator and the seventh temperature sensor value at the outlet 27 of the second branch outlet of the evaporator; the temperature difference ΔT3 is calculated by comparing the temperature difference between the fourth temperature sensor value at the inlet 23 of the third branch outlet of the evaporator and the eighth temperature sensor value at the outlet 26 of the third branch outlet of the evaporator; and the temperature difference ΔT4 is calculated by comparing the temperature difference between the fifth temperature sensor value at the inlet 24 of the fourth branch outlet of the evaporator and the ninth temperature sensor value at the outlet 25 of the fourth branch outlet of the evaporator. Calculate the difference ΔT5 between the maximum value {max(temperature values ​​of the sixth, seventh, eighth, and ninth temperature sensors)} and the minimum value {min(temperature values ​​of the sixth, seventh, eighth, and ninth temperature sensors)} among the four temperature sensor values ​​at the outlet temperatures of the four branches. Calculate the difference ΔT6 between the maximum value {max(temperature values ​​of the second, third, fourth, and fifth temperature sensors)} and the minimum value {min(temperature values ​​of the second, third, fourth, and fifth temperature sensors)} among the four temperature sensor values ​​at the inlet temperatures of the four branches.

[0059] In step S140, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, based on the total temperature difference of the indoor heat exchanger and the branch temperature difference of the n branches, it is preliminarily determined whether the indoor heat exchanger has experienced uneven refrigerant distribution.

[0060] In step S150, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, if it is initially determined that the indoor heat exchanger has experienced uneven refrigerant distribution, then under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in combination with the branch temperature difference of the n branches, it is further determined whether the indoor heat exchanger has experienced uneven refrigerant distribution. Of course, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, if it is initially determined that there is no refrigerant uneven distribution in the indoor heat exchanger, the air conditioner is controlled to continue operating according to the preset operating mode. Then, it returns to the previous state to re-acquire the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches. The total temperature difference of the indoor heat exchanger, the branch temperature difference of the n branches, the outlet temperature difference of the n branches, and the inlet temperature difference of the n branches are then re-determined. Based on the re-determined total temperature difference of the indoor heat exchanger and the branch temperature difference of the n branches, it is further preliminarily determined whether there is a refrigerant uneven distribution in the indoor heat exchanger. This cycle is repeated to achieve dynamic monitoring of the pipe temperature of the indoor heat exchanger of the air conditioner.

[0061] In step S160, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, if it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, then the fault location of the uneven refrigerant distribution in the indoor heat exchanger is determined, and a reminder message for the fault location is initiated; and, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, the compressor of the air conditioner is controlled to operate at a reduced frequency based on the branch temperature difference of the n branches. Of course, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, if it is further determined that there is no refrigerant uneven distribution in the indoor heat exchanger, the air conditioner is controlled to continue operating according to the preset operating mode. Then, it returns to the previous state to re-acquire the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches. The total temperature difference of the indoor heat exchanger, the branch temperature difference of the n branches, the outlet temperature difference of the n branches, and the inlet temperature difference of the n branches are then re-determined. Based on the re-determined total temperature difference of the indoor heat exchanger and the branch temperature difference of the n branches, it is further preliminarily determined whether there is a refrigerant uneven distribution in the indoor heat exchanger. This cycle is repeated to achieve dynamic monitoring of the pipe temperature of the indoor heat exchanger of the air conditioner.

[0062] The present invention proposes a method to improve the reliability of an air conditioner indoor unit. By utilizing multiple temperature sensors in the indoor unit, the potential for frost buildup is significantly reduced. Simultaneously, the method enhances the assessment of various flow paths within the evaporator. Thus, by strengthening the assessment of the indoor unit's temperature, the reliability of the indoor unit's control is improved, reducing the risk of freezing or frost buildup.

[0063] In some embodiments, in step S140, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, the process of initially determining whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the total temperature difference of the indoor heat exchanger and the branch temperature difference of the n branches is described in the following exemplary description.

[0064] The following is combined with Figure 2The illustrated flowchart shows an embodiment of the method of the present invention, which preliminarily determines whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches. Further explanation is provided regarding the specific process of preliminarily determining whether the indoor heat exchanger has experienced uneven refrigerant distribution in step S140, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current position of the indoor unit's air guide plate, based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches. This includes steps S210 to S230.

[0065] Step S210: Based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set total temperature difference threshold, determine the current total temperature difference threshold of the indoor heat exchanger under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set branch temperature difference threshold, determine the current branch temperature difference threshold of the n branches under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit.

[0066] Step S220: Determine whether the total temperature difference of the indoor heat exchanger is less than the current total temperature difference threshold of the indoor heat exchanger. If yes, it is preliminarily determined that the indoor heat exchanger has experienced uneven refrigerant distribution. Otherwise, it is preliminarily determined that the indoor heat exchanger has not experienced uneven refrigerant distribution.

[0067] Step S230: Determine whether the branch temperature difference of each of the n branches is less than the current branch temperature difference threshold of the n branches. If yes, it is preliminarily determined that the indoor heat exchanger has uneven refrigerant distribution and that the branch has weld blockage, and a reminder message indicating that the branch has weld blockage is issued. Otherwise, it is preliminarily determined that the indoor heat exchanger does not have uneven refrigerant distribution.

[0068] Specifically, such as Figure 7 As shown, the method for determining the temperature of the indoor unit of a split air conditioner also includes: Step 4, comparing the collected values ​​with the temperature difference data stored in the internal chip of the air conditioner under the current air conditioner mode, indoor unit fan speed, and indoor unit deflector status. The pre-stored temperature difference data will differ under different modes, fan speeds, and deflector statuses.

[0069] After the user powers on the air conditioner, the current operating mode is set to cooling mode, the air deflector position is set to the default position, and the indoor unit fan speed is set to high. After running stably for 10 minutes, temperature difference data is collected, and ΔT, ΔT1, ΔT2, ΔT3, and ΔT4 are calculated. It is then determined whether this temperature difference value is less than the value stored in the chip.

[0070] The total temperature difference ΔT and the temperature differences of each branch ΔT1 to ΔT4 all need to be determined. For example, if the total temperature difference ΔT is less than the pre-stored temperature difference value, it is considered that there may be an uneven distribution problem, and steps 5 and 6 need to be performed. If the value of ΔT1 is small, that is, ΔT1 is less than the pre-stored temperature difference data, it is considered that there may be defects such as welding blockage in the first branch. At this time, the compressor frequency can be reduced in step S160 until the machine is shut down and a fault is reported.

[0071] In some embodiments, in step S150, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, the specific process of further determining whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in combination with the branch temperature difference of the n branches, is described in the following exemplary description.

[0072] The following is combined with Figure 3 The illustrated flowchart shows an embodiment of the method of the present invention, which further determines whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the outlet temperature difference, inlet temperature difference, and branch temperature difference of the n branches. Further explanation is provided regarding the specific process of determining whether the indoor heat exchanger has experienced uneven refrigerant distribution in step S150, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, based on the outlet temperature difference and inlet temperature difference of the n branches, and in combination with the branch temperature difference of the n branches. This includes steps S310 to S330.

[0073] Step S310: Based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set outlet temperature difference threshold, determine the current outlet temperature difference threshold of the indoor heat exchanger under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and, based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set inlet temperature difference threshold, determine the current inlet temperature difference threshold of the indoor heat exchanger under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit.

[0074] Step S320: Determine whether the outlet temperature difference of the n branches is greater than the current outlet temperature difference threshold of the indoor heat exchanger. If yes, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution is due to the uneven refrigerant distribution in the n branches. Otherwise, further determine that the indoor heat exchanger has not experienced uneven refrigerant distribution.

[0075] Step S330: Determine whether the inlet temperature difference of the n branches is greater than the current inlet temperature difference threshold of the indoor heat exchanger. If yes, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution caused by the distributor of the indoor heat exchanger. Otherwise, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution in the n branches.

[0076] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner further includes: Step 5, calculating △T, △T1, △T2, △T3, and △T4, and simultaneously calculating △T5 and △T6. If the difference △T5 is greater than the temperature difference data set in the air conditioner's refrigerant control system, it is considered that there is uneven flow distribution in these four branches. If the temperature difference △T6 is greater than the temperature difference data set in the air conditioner's refrigerant control system, it is determined that the abnormality in the air conditioner's refrigerant control system is caused by uneven flow distribution in the distributor. If the temperature difference △T6 is within the set temperature difference data, it is determined that the abnormality in the air conditioner's refrigerant control system occurs in one of the four branches.

[0077] In some implementations, in step S160, given the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide vane position of the indoor unit, if it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, then the fault location of the uneven refrigerant distribution in the indoor heat exchanger is determined, and a reminder message for the fault location is initiated, including any of the following methods for reminding of the fault location:

[0078] The first method for alerting about the fault location is as follows: If it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the cause of the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution in the distributor of the indoor heat exchanger, then the fault location of the uneven refrigerant distribution in the indoor heat exchanger is determined to be the distributor, and an alert message for uneven refrigerant distribution in the distributor is initiated.

[0079] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner also includes: in step 5, if the temperature difference ΔT6 is greater than the temperature difference data set in the refrigerant control system of the air conditioner, it is determined that the abnormality in the refrigerant control system of the air conditioner is caused by uneven flow distribution in the distributor. After uneven flow distribution occurs, an abnormality reminder message for uneven flow distribution in the distributor is issued (such as displaying a fault message for uneven flow distribution in the distributor on the display screen).

[0080] The second method for alerting about the fault location is as follows: If it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution in the n branches, then the maximum value among the branch temperature differences of the n branches is determined, the branch corresponding to the maximum value is locked as the branch with uneven refrigerant distribution, and an alert message for uneven refrigerant distribution in that branch is initiated.

[0081] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner further includes: in step 5, if the temperature difference △T6 is within the set temperature difference data, it is determined that the abnormality in the refrigerant control system of the air conditioner occurs in one of the four branches; by comparing the temperature differences △T1, △T2, △T3 and △T4 in the four branches, the branch with the largest temperature difference change can be further identified, and an abnormal reminder message of uneven flow distribution in that branch can be issued (such as displaying a fault message of uneven flow distribution in that branch on the display screen).

[0082] In some embodiments, in step S160, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, the specific process of controlling the compressor of the air conditioner to operate at a reduced frequency according to the branch temperature difference of the n branches is described in the following exemplary description.

[0083] The following is combined with Figure 4 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention, which controls the compressor of the air conditioner to operate at a reduced frequency according to the branch temperature difference of n branches. It further illustrates the specific process of controlling the compressor of the air conditioner to operate at a reduced frequency according to the branch temperature difference of the n branches in step S160, under the current operating mode of the air conditioner, the current fan speed of the indoor fan and the current air guide plate position of the indoor unit, including steps S410 to S440.

[0084] Step S410: Determine the minimum value among the branch temperature differences of the n branches; determine the target frequency of the air conditioner compressor based on the inlet and outlet temperatures of the branch corresponding to the minimum value.

[0085] Step S420: The current frequency of the compressor is reduced to the target frequency of the compressor at a set frequency reduction rate to correct the current frequency of the compressor and make the compressor operate at a reduced frequency.

[0086] Step S430: After the second set time, continue to correct the current frequency of the compressor to make the compressor operate at a lower frequency. The second set time is, for example, 10 minutes.

[0087] Step S440 is repeated until the current frequency of the compressor drops to a preset minimum frequency. After the air conditioner continues to run for a third set time, if it is still determined that the indoor heat exchanger has uneven refrigerant distribution, the air conditioner is shut down. The third set time is, for example, 30 minutes.

[0088] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner further includes: In step 5, if the temperature difference ΔT6 is greater than the temperature difference data set in the refrigerant control system of the air conditioner, it is determined that the abnormality in the refrigerant control system of the air conditioner is caused by uneven flow distribution in the distributor. After uneven flow distribution occurs, an abnormality reminder message for uneven flow distribution in the distributor is issued (such as displaying a fault message for uneven flow distribution in the distributor on the display screen), and the compressor is made to operate at a reduced frequency. Specifically, when reducing the compressor operating frequency, the frequency reduction rate is 5Hz / s, and the temperature difference is checked every 10 minutes to correct the compressor frequency until it is reduced to the lowest frequency of 20Hz; after reducing to the lowest frequency of 20Hz, it continues to run for a period of time, such as 30 minutes. If the uneven flow distribution in the distributor still exists, the air conditioner is controlled to shut down.

[0089] In step 5, if the temperature difference ΔT6 is within the set temperature difference data, it is determined that the abnormality in the refrigerant control system of the air conditioner occurs in one of the four branches. By comparing the temperature differences ΔT1, ΔT2, ΔT3, and ΔT4 in the four branches, the branch with the largest temperature difference change can be further identified, and an abnormality alert message indicating uneven flow distribution in that branch can be issued (such as displaying a fault message indicating uneven flow distribution in that branch on the display screen). The compressor will then operate at a reduced frequency. When the compressor operates at a reduced frequency, the compressor frequency is calculated based on the smallest temperature difference among ΔT1, ΔT2, ΔT3, and ΔT4, which is the inlet and outlet temperature difference, thereby reducing the compressor operating frequency. The frequency reduction rate is 5Hz / s, and the temperature difference is checked every 10 minutes to correct the compressor frequency until it is reduced to the minimum frequency of 20Hz. After reducing to the minimum frequency of 20Hz, the system continues to run for a period of time, such as 30 minutes. If the uneven flow distribution phenomenon still exists in that branch, the air conditioner will be shut down.

[0090] The solution of this invention can accurately determine overheating in the flow path by using multi-sensor temperature judgment. It can also effectively alleviate the possibility of freezing or frosting of the indoor unit by reducing the compressor operating frequency. Furthermore, it can pinpoint the location of the problem by measuring temperature changes, thereby further solving the problem. This is beneficial to improving the reliability of the air conditioner and also facilitates the handling of after-sales issues, helping repair technicians to find the problem as quickly as possible.

[0091] The technical solution of this embodiment involves using an indoor heat exchanger (such as an evaporator) with n inlets and n outlets in the indoor unit of an air conditioner. The total inlet of the indoor heat exchanger is connected to the n inlets of the n branches, and the n outlets of the n branches are connected to the total outlet of the indoor heat exchanger. The n branches are arranged in parallel between the total inlet and the total outlet of the indoor heat exchanger, where n is a positive integer greater than or equal to 2. The system operates in the current mode, with the current indoor unit fan speed and the current air guide vane position. After a period of stable operation (e.g., 10 minutes), the total inlet and outlet temperatures of the indoor heat exchanger, as well as the inlet and outlet temperatures of each of the n branches of the indoor heat exchanger, are collected. The total temperature difference (e.g., ΔT) between the total inlet and outlet temperatures of the indoor heat exchanger is determined. The branch temperature difference (e.g., ΔT1, ΔT2, ΔT3, and ΔT4) between the inlet and outlet temperatures of each branch is determined to obtain the branch temperature differences of the n branches. Finally, the maximum and minimum outlet temperatures of the n branches are determined. Calculate the outlet temperature difference between the n branches (e.g., ΔT5) and the inlet temperature difference between the maximum and minimum inlet temperatures of the n branches (e.g., ΔT6). Based on the total temperature difference (e.g., ΔT), the branch temperature differences of the n branches (e.g., ΔT1, ΔT2, ΔT3, and ΔT4), the outlet temperature difference of the n branches (e.g., ΔT5), and the inlet temperature difference of the n branches (e.g., ΔT6), determine whether there is uneven refrigerant distribution in the indoor heat exchanger, and determine whether the uneven refrigerant distribution occurs at the distributor or the inlet heat exchanger itself. A branch of the heat exchanger alerts users to locations where refrigerant distribution is uneven in the indoor heat exchanger. The compressor frequency is determined based on the minimum branch temperature difference among the n branches, causing the compressor to operate at a reduced frequency. By combining the temperatures of the total inlet and outlet of the indoor heat exchanger, as well as the inlet and outlet temperatures of each branch, the uniformity of refrigerant distribution in the indoor heat exchanger is assessed. When uneven refrigerant distribution occurs, the fault location is identified, an alert is issued, and the compressor is controlled to operate at a reduced frequency, thus improving the reliability of the indoor unit control.

[0092] According to an embodiment of the present invention, a control device for an air conditioner corresponding to a control method for an air conditioner is also provided. The air conditioner has an outdoor unit and an indoor unit; the outdoor unit has a compressor; the indoor unit has an indoor heat exchanger, an indoor fan, and an air guide plate assembly, wherein the indoor heat exchanger is such as an evaporator, the indoor fan is such as an indoor unit fan, and the air guide plate assembly is such as an assembly composed of a first air guide plate and a second air guide plate; the indoor heat exchanger has n inlets and n outlets, where n is a positive integer greater than or equal to 2; the total inlet of the indoor heat exchanger is connected to the n inlets of the n branches, and the n outlets of the n branches are connected to the total outlet of the indoor heat exchanger.

[0093] Specifically, Figure 8This is a schematic diagram of one embodiment of a four-inlet, four-outlet evaporator. Figure 8 As shown, a first temperature sensor is installed at the main inlet of the evaporator. The main inlet of the evaporator is divided into four branch inlets by a distributor, such as the first branch inlet 21, the second branch inlet 22, the third branch inlet 23, and the fourth branch inlet 24. Each of the four branches is equipped with a temperature sensor: a second temperature sensor, a third temperature sensor, a fourth temperature sensor, and a fifth temperature sensor. Corresponding to the four branch inlets, there are four branch outlets, such as the first branch outlet 28, the second branch outlet 27, the third branch outlet 26, and the fourth branch outlet 25. Each of the four branch outlets is also equipped with a temperature sensor: a sixth temperature sensor, a seventh temperature sensor, an eighth temperature sensor, and a ninth temperature sensor. At the same time, the outlets of the four branches are collected by a gas collecting pipe and converged at the main outlet of the evaporator, where a tenth temperature sensor is installed.

[0094] Figure 8 The example shown is based on a four-inlet, four-outlet evaporator, but the solution of the present invention is also applicable to a two-inlet, two-outlet evaporator. Figure 9 This is a schematic diagram of one embodiment of a two-inlet, two-outlet evaporator. Figure 9 As shown, a first temperature sensor is installed at the main inlet of the evaporator. The main inlet of the evaporator is divided into two branch inlets via a distributor 29, such as the first branch inlet 21 and the second branch inlet 22. Each branch inlet is equipped with two temperature sensors: a second temperature sensor and a third temperature sensor. Corresponding to the two branch inlets, there are two branch outlets, such as the first branch outlet 28 and the second branch outlet 27. Each branch outlet is also equipped with two temperature sensors, namely the sixth temperature sensor and the seventh temperature sensor. The outlets of the two branches are combined into the main outlet of the evaporator via a gas collecting pipe, where a tenth temperature sensor is installed.

[0095] See Figure 5 The diagram shows a structural schematic of an embodiment of the device of the present invention. The control device of the air conditioner may include: an acquisition unit 102 and a control unit 104.

[0096] The control unit 104 is configured to, after the air conditioner is turned on, determine the current operating mode of the air conditioner, determine the current fan speed of the indoor fan, and determine the current position of the air guide vane of the indoor unit. The specific functions and processing of this control unit 104 are described in step S110.

[0097] In some implementations, the current operating mode of the air conditioner is either cooling mode or heating mode. In addition, if the air conditioner is operating in fan mode, the air conditioner compressor will not start, and there will be no problems such as large temperature difference at the evaporator outlet and frost on the evaporator surface due to uneven refrigerant distribution. In this case, the air conditioner can operate according to the preset program.

[0098] Specifically, Figure 7 This is a flowchart illustrating an embodiment of a method for determining the temperature of the indoor unit of a split-type air conditioner. Figure 7 In the example shown, the evaporator uses a four-inlet, four-outlet configuration (see [link]). Figure 8 (Example shown). Figure 7 As shown, the method for determining the temperature of the indoor unit of a split air conditioner includes:

[0099] Step 1: Each time the unit is turned on, determine the current operating mode of the air conditioner, i.e., determine which mode the air conditioner is currently operating in, such as cooling mode, heating mode, or fan mode, and then proceed to Step 2.

[0100] Step 2: If the air conditioner is currently in cooling mode, then proceed to step 3 in cooling mode.

[0101] In some implementations, the current fan speed of the indoor fan is any one of the preset high speed, preset high speed, preset medium speed, preset low speed, and preset silent speed.

[0102] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner also includes: Step 3, judging which of the following levels the current indoor unit fan is in: super strong, high wind, medium wind, low wind, or silent mode. For example, if the current indoor unit fan is determined to be in medium wind mode.

[0103] In some embodiments, the indoor unit has a first air guide plate and a second air guide plate; the current air guide plate position of the indoor unit is any combination of the following: a default combination position of the first air guide plate and the second air guide plate, a first combination position of the first air guide plate and the second air guide plate, a second combination position of the first air guide plate and the second air guide plate, a third combination position of the first air guide plate and the second air guide plate, and a fourth combination position of the first air guide plate and the second air guide plate. The default combination position is such as the default position; the first combination position is such as position one; the second combination position is such as position two; the third combination position is such as position three; and the fourth combination position is such as position four.

[0104] Specifically, Figure 6This is a schematic diagram of the air guide vane angle of the indoor unit of a split air conditioner, specifically showing the structure of the indoor unit's air guide vane in different positions. For example... Figure 6 As shown, the indoor unit of a split air conditioner includes: an evaporator 11, a first cross-flow fan blade 12, a panel 13, a first air guide plate, a second air guide plate, and a return air grille 19. Inside the panel 13 of the indoor unit, along the direction from the return air inlet to the air outlet, the return air grille 19, the evaporator 11, and the first cross-flow fan blade 12 are arranged. At the air outlet, the first air guide plate and the second air guide plate are arranged. The first air guide plate can be in a first position (i.e., the position when the first air guide plate is closed), a second position (i.e., the middle position within the rotation range of the first air guide plate in the air outlet), and a third position (i.e., the maximum opening position of the first air guide plate). The second air guide plate can be in the first position (i.e., the position when the second air guide plate is closed), and the second air guide plate can also be in the second position (i.e., the second air guide plate is in the middle position within the rotation range of the second air guide plate in the air outlet or the second air guide plate is in the position where the second air guide plate is half open).

[0105] like Figure 6 As shown, the states of the first air guide plate are: the first position (closed state) 14, the second position (middle position) 15, and the third position (maximum position) 16, which respectively represent the first air guide plate being in the closed position, the middle position, and the maximum position. The states of the second air guide plate are: the first position (closed state) 17 and the second position 18, which respectively represent the second air guide plate being in the closed position and the half-open position. The angle of the first position (closed state) 14 of the first air guide plate ranges from 40° to 45°, the angle of the second position (middle position) 15 of the first air guide plate ranges from 55° to 60°, the angle of the third position (maximum position) 16 of the first air guide plate ranges from 65° to 70°, and the angle is 0° if the first air guide plate is completely closed and close to the panel; the first position (closed state) 17 of the second air guide plate indicates that it is closed and the angle is 0°, and the angle of the second position 18 of the second air guide plate ranges from 20° to 30°.

[0106] like Figure 7 As shown, the method for determining the temperature of the indoor unit of a split air conditioner further includes: in step 3, after determining the current fan speed of the indoor unit, determining which of the following positions the current combined position of the first and second air guide vanes is: the default position, position one, position two, position three, or position four. Specifically, as shown... Figure 6As shown, the default position is a combination of the second position (middle position) 15 of the first air guide plate and the first position (closed state) 17 of the second air guide plate. Position 1 is a combination of the first position (closed state) 14 of the first air guide plate and the first position (closed state) 17 of the second air guide plate. Position 2 is a combination of the third position (maximum position) 16 of the first air guide plate and the first position (closed state) 17 of the second air guide plate. Position 3 is a combination of the second position (middle position) 15 of the first air guide plate and the second position 18 of the second air guide plate. Position 4 is a combination of the third position (maximum position) 16 of the first air guide plate and the second position 18 of the second air guide plate. To prevent users from frequently switching the indoor unit fan speed and air guide plate position after powering on, only after the air conditioner mode, indoor fan speed, and air guide plate position remain unchanged, and the temperature difference is checked after 10 minutes, i.e., step 4 is executed.

[0107] The acquisition unit 102 is configured to acquire, after the air conditioner has been running for a first set time in its current operating mode, at the current fan speed of the indoor fan, and at the current air guide vane position of the indoor unit, the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches. The first set time is, for example, 10 minutes. For the specific functions and processing of this acquisition unit 102, please refer to step S120.

[0108] The control unit 104 is further configured to: determine the temperature difference between the total inlet temperature and the total outlet temperature of the indoor heat exchanger, denoted as the total temperature difference of the indoor heat exchanger, such as temperature difference ΔT; determine the temperature difference between the inlet temperature and the outlet temperature of each of the n branches, obtaining the temperature difference of that branch, and obtaining the temperature differences of the n branches, denoted as the branch temperature differences of the n branches, such as temperature difference ΔT1, temperature difference ΔT2, temperature difference ΔT3, and temperature difference ΔT4; determine the temperature difference between the maximum and minimum outlet temperatures of the n branches, denoted as the outlet temperature difference of the n branches, such as temperature difference ΔT5; and determine the temperature difference between the maximum and minimum inlet temperatures of the n branches, denoted as the inlet temperature difference of the n branches, such as temperature difference ΔT6. The specific functions and processing of this control unit 104 are described in step S130.

[0109] Specifically, see Figure 8 and Figure 9The example shown is as follows: The temperature difference between the first temperature sensor value at the main inlet of the evaporator and the tenth temperature sensor value at the main outlet of the evaporator is ΔT; the temperature difference ΔT1 is calculated by comparing the temperature difference between the second temperature sensor value at the inlet 21 of the first branch outlet of the evaporator and the sixth temperature sensor value at the outlet 28 of the first branch outlet of the evaporator; the temperature difference ΔT2 is calculated by comparing the temperature difference between the third temperature sensor value at the inlet 22 of the second branch outlet of the evaporator and the seventh temperature sensor value at the outlet 27 of the second branch outlet of the evaporator; the temperature difference ΔT3 is calculated by comparing the temperature difference between the fourth temperature sensor value at the inlet 23 of the third branch outlet of the evaporator and the eighth temperature sensor value at the outlet 26 of the third branch outlet of the evaporator; and the temperature difference ΔT4 is calculated by comparing the temperature difference between the fifth temperature sensor value at the inlet 24 of the fourth branch outlet of the evaporator and the ninth temperature sensor value at the outlet 25 of the fourth branch outlet of the evaporator. Calculate the difference ΔT5 between the maximum value {max(temperature values ​​of the sixth, seventh, eighth, and ninth temperature sensors)} and the minimum value {min(temperature values ​​of the sixth, seventh, eighth, and ninth temperature sensors)} among the four temperature sensor values ​​at the outlet temperatures of the four branches. Calculate the difference ΔT6 between the maximum value {max(temperature values ​​of the second, third, fourth, and fifth temperature sensors)} and the minimum value {min(temperature values ​​of the second, third, fourth, and fifth temperature sensors)} among the four temperature sensor values ​​at the inlet temperatures of the four branches.

[0110] The control unit 104 is further configured to, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, preliminarily determine whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the total temperature difference of the indoor heat exchanger and the branch temperature difference of the n branches. The specific functions and processing of this control unit 104 are described in step S140.

[0111] The control unit 104 is further configured to, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, if it is initially determined that the indoor heat exchanger has an uneven refrigerant distribution, then, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, further determine whether the indoor heat exchanger has an uneven refrigerant distribution based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in combination with the branch temperature difference of the n branches. Of course, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current position of the air guide vane of the indoor unit, if it is initially determined that there is no refrigerant uneven distribution in the indoor heat exchanger, the air conditioner is controlled to continue operating according to the preset operating mode. Then, it returns to the previous state to re-acquire the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches. The total temperature difference of the indoor heat exchanger, the branch temperature difference of the n branches, the outlet temperature difference of the n branches, and the inlet temperature difference of the n branches are then re-determined. Based on the re-determined total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches, it is further preliminarily determined whether there is refrigerant uneven distribution in the indoor heat exchanger. This cycle is repeated to achieve dynamic monitoring of the indoor heat exchanger pipe temperature of the air conditioner. For the specific functions and processing of this control unit 104, please refer to step S150.

[0112] The control unit 104 is further configured to, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, if it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, determine the fault location of the uneven refrigerant distribution in the indoor heat exchanger and initiate a reminder message for the fault location; and, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, control the compressor of the air conditioner to operate at a reduced frequency based on the branch temperature difference of the n branches. Of course, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current position of the air guide vane of the indoor unit, if it is further determined that there is no refrigerant uneven distribution in the indoor heat exchanger, the air conditioner is controlled to continue operating according to the preset operating mode. Then, it returns to the previous state to re-acquire the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches. The total temperature difference of the indoor heat exchanger, the branch temperature difference of the n branches, the outlet temperature difference of the n branches, and the inlet temperature difference of the n branches are then re-determined. Based on the re-determined total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches, a preliminary determination is made as to whether there is refrigerant uneven distribution in the indoor heat exchanger. This cycle is repeated to achieve dynamic monitoring of the indoor heat exchanger pipe temperature of the air conditioner. For the specific functions and processing of this control unit 104, please refer to step S160.

[0113] The present invention proposes a device to improve the reliability of an air conditioner indoor unit. By using multiple temperature sensors in the indoor unit, the potential for frost buildup is significantly reduced. Simultaneously, the device enhances the assessment of each flow path in the evaporator. Thus, by strengthening the assessment of the indoor unit's temperature, the reliability of the indoor unit's control is improved, reducing the risk of freezing or frost buildup.

[0114] In some embodiments, the control unit 104, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, preliminarily determines whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches, including:

[0115] The control unit 104 is further configured to determine the current total temperature difference threshold of the indoor heat exchanger based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set total temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and to determine the current branch temperature difference threshold of the n branches based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set branch temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit. The specific functions and processing of this control unit 104 are described in step S210.

[0116] The control unit 104 is further configured to determine whether the total temperature difference of the indoor heat exchanger is less than the current total temperature difference threshold of the indoor heat exchanger: if so, it is preliminarily determined that the indoor heat exchanger has experienced uneven refrigerant distribution. Otherwise, it is preliminarily determined that the indoor heat exchanger has not experienced uneven refrigerant distribution. The specific functions and processing of this control unit 104 are described in step S220.

[0117] The control unit 104 is further configured to determine whether the branch temperature difference of each of the n branches is less than the current branch temperature difference threshold of the n branches. If so, it is preliminarily determined that the indoor heat exchanger has experienced uneven refrigerant distribution and that the branch has a weld blockage, and a warning message indicating that the branch has a weld blockage is issued. Otherwise, it is preliminarily determined that the indoor heat exchanger does not have an uneven refrigerant distribution. The specific functions and processing of the control unit 104 are described in step S230.

[0118] Specifically, such as Figure 7 As shown, the method for determining the temperature of the indoor unit of a split air conditioner also includes: Step 4, comparing the collected values ​​with the temperature difference data stored in the internal chip of the air conditioner under the current air conditioner mode, indoor unit fan speed, and indoor unit deflector status. The pre-stored temperature difference data will differ under different modes, fan speeds, and deflector statuses.

[0119] After the user powers on the air conditioner, the current operating mode is set to cooling mode, the air deflector position is set to the default position, and the indoor unit fan speed is set to high. After running stably for 10 minutes, temperature difference data is collected, and ΔT, ΔT1, ΔT2, ΔT3, and ΔT4 are calculated. It is then determined whether this temperature difference value is less than the value stored in the chip.

[0120] The total temperature difference ΔT and the temperature differences of each branch ΔT1 to ΔT4 all need to be determined. For example, if the total temperature difference ΔT is less than the pre-stored temperature difference value, it is considered that there may be an uneven distribution problem, and steps 5 and 6 need to be performed. If the value of ΔT1 is small, that is, ΔT1 is less than the pre-stored temperature difference data, it is considered that there may be defects such as welding blockage in the first branch. At this time, the compressor frequency can be reduced in step S160 until the machine is shut down and a fault is reported.

[0121] In some embodiments, the control unit 104, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, further determines whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in combination with the branch temperature difference of the n branches, including:

[0122] The control unit 104 is further configured to determine the current outlet temperature difference threshold of the indoor heat exchanger based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set outlet temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and to determine the current inlet temperature difference threshold of the indoor heat exchanger based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set inlet temperature difference threshold, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit. The specific functions and processing of this control unit 104 are described in step S310.

[0123] The control unit 104 is further configured to determine whether the outlet temperature difference of the n branches is greater than the current outlet temperature difference threshold of the indoor heat exchanger. If so, it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is assumed that the reason for the uneven refrigerant distribution is due to the uneven refrigerant distribution in the n branches. Otherwise, it is further determined that the indoor heat exchanger has not experienced uneven refrigerant distribution. The specific functions and processing of this control unit 104 are described in step S320.

[0124] The control unit 104 is further configured to determine whether the inlet temperature difference of the n branches is greater than the current inlet temperature difference threshold of the indoor heat exchanger. If so, it further determines that the indoor heat exchanger has experienced uneven refrigerant distribution, and considers that the uneven refrigerant distribution is due to uneven distribution by the distributor of the indoor heat exchanger. Otherwise, it further determines that the indoor heat exchanger has experienced uneven refrigerant distribution, and considers that the uneven refrigerant distribution is due to uneven refrigerant distribution in the n branches. The specific functions and processing of this control unit 104 are described in step S330.

[0125] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner further includes: Step 5, calculating △T, △T1, △T2, △T3, and △T4, and simultaneously calculating △T5 and △T6. If the difference △T5 is greater than the temperature difference data set in the air conditioner's refrigerant control system, it is considered that there is uneven flow distribution in these four branches. If the temperature difference △T6 is greater than the temperature difference data set in the air conditioner's refrigerant control system, it is determined that the abnormality in the air conditioner's refrigerant control system is caused by uneven flow distribution in the distributor. If the temperature difference △T6 is within the set temperature difference data, it is determined that the abnormality in the air conditioner's refrigerant control system occurs in one of the four branches.

[0126] In some embodiments, if the control unit 104, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide vane position of the indoor unit, further determines that the indoor heat exchanger has experienced uneven refrigerant distribution, then determines the fault location of the uneven refrigerant distribution in the indoor heat exchanger and initiates a reminder message for the fault location, including any of the following methods for reminding of the fault location:

[0127] The first method for alerting the fault location is as follows: The control unit 104 is further configured to, if it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution in the distributor of the indoor heat exchanger, then determine the fault location of the uneven refrigerant distribution in the indoor heat exchanger as the distributor, and initiate an alert message for uneven refrigerant distribution in the distributor.

[0128] Specifically, such as Figure 7As shown, the method for judging the temperature of the indoor unit of a split air conditioner also includes: in step 5, if the temperature difference ΔT6 is greater than the temperature difference data set in the refrigerant control system of the air conditioner, it is determined that the abnormality in the refrigerant control system of the air conditioner is caused by uneven flow distribution in the distributor. After uneven flow distribution occurs, an abnormality reminder message for uneven flow distribution in the distributor is issued (such as displaying a fault message for uneven flow distribution in the distributor on the display screen).

[0129] The second method for alerting about the fault location is as follows: The control unit 104 is further configured to, if it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution in the n branches, determine the maximum value among the branch temperature differences of the n branches, lock the branch corresponding to the maximum value as the branch with uneven refrigerant distribution, and initiate an alert message for the uneven refrigerant distribution in that branch.

[0130] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner further includes: in step 5, if the temperature difference △T6 is within the set temperature difference data, it is determined that the abnormality in the refrigerant control system of the air conditioner occurs in one of the four branches; by comparing the temperature differences △T1, △T2, △T3 and △T4 in the four branches, the branch with the largest temperature difference change can be further identified, and an abnormal reminder message of uneven flow distribution in that branch can be issued (such as displaying a fault message of uneven flow distribution in that branch on the display screen).

[0131] In some embodiments, the control unit 104, under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, controls the compressor of the air conditioner to operate at a reduced frequency based on the branch temperature difference of the n branches, including:

[0132] The control unit 104 is further configured to determine the minimum value among the branch temperature differences of the n branches; and to determine the target frequency of the air conditioner's compressor based on the inlet and outlet temperatures of the branch corresponding to the minimum value. The specific functions and processing of the control unit 104 are described in step S410.

[0133] The control unit 104 is further configured to reduce the current frequency of the compressor to the target frequency of the compressor at a set reduction rate, thereby correcting the current frequency of the compressor and causing the compressor to operate at a reduced frequency. The specific functions and processing of this control unit 104 are described in step S420.

[0134] The control unit 104 is further configured to continue correcting the current frequency of the compressor after a second set time, causing the compressor to operate at a lower frequency. The second set time is, for example, 10 minutes. The specific functions and processing of the control unit 104 are described in step S430.

[0135] The control unit 104 is further configured to cycle through this process until the current frequency of the compressor drops to a preset minimum frequency. After controlling the air conditioner to continue running for a third set time, if it is still determined that the indoor heat exchanger has uneven refrigerant distribution, the air conditioner will be shut down. The third set time is, for example, 30 minutes. The specific functions and processing of this control unit 104 are described in step S440.

[0136] Specifically, such as Figure 7 As shown, the method for judging the temperature of the indoor unit of a split air conditioner further includes: In step 5, if the temperature difference ΔT6 is greater than the temperature difference data set in the refrigerant control system of the air conditioner, it is determined that the abnormality in the refrigerant control system of the air conditioner is caused by uneven flow distribution in the distributor. After uneven flow distribution occurs, an abnormality reminder message for uneven flow distribution in the distributor is issued (such as displaying a fault message for uneven flow distribution in the distributor on the display screen), and the compressor is made to operate at a reduced frequency. Specifically, when reducing the compressor operating frequency, the frequency reduction rate is 5Hz / s, and the temperature difference is checked every 10 minutes to correct the compressor frequency until it is reduced to the lowest frequency of 20Hz; after reducing to the lowest frequency of 20Hz, it continues to run for a period of time, such as 30 minutes. If the uneven flow distribution in the distributor still exists, the air conditioner is controlled to shut down.

[0137] In step 5, if the temperature difference ΔT6 is within the set temperature difference data, it is determined that the abnormality in the refrigerant control system of the air conditioner occurs in one of the four branches. By comparing the temperature differences ΔT1, ΔT2, ΔT3, and ΔT4 in the four branches, the branch with the largest temperature difference change can be further identified, and an abnormality alert message indicating uneven flow distribution in that branch can be issued (such as displaying a fault message indicating uneven flow distribution in that branch on the display screen). The compressor will then operate at a reduced frequency. When the compressor operates at a reduced frequency, the compressor frequency is calculated based on the smallest temperature difference among ΔT1, ΔT2, ΔT3, and ΔT4, which is the inlet and outlet temperature difference, thereby reducing the compressor operating frequency. The frequency reduction rate is 5Hz / s, and the temperature difference is checked every 10 minutes to correct the compressor frequency until it is reduced to the minimum frequency of 20Hz. After reducing to the minimum frequency of 20Hz, the system continues to run for a period of time, such as 30 minutes. If the uneven flow distribution phenomenon still exists in that branch, the air conditioner will be shut down.

[0138] The solution of this invention can accurately determine overheating in the flow path by using multi-sensor temperature judgment. It can also effectively alleviate the possibility of freezing or frosting of the indoor unit by reducing the compressor operating frequency. Furthermore, it can pinpoint the location of the problem by measuring temperature changes, thereby further solving the problem. This is beneficial to improving the reliability of the air conditioner and also facilitates the handling of after-sales issues, helping repair technicians to find the problem as quickly as possible.

[0139] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0140] The technical solution of this invention involves an indoor heat exchanger (e.g., an evaporator) with n inlets and n outlets in the indoor unit of an air conditioner. The main inlet of the indoor heat exchanger is connected to the n inlets of each of the n branches, and the n outlets of each of the n branches are connected to the main outlet of the indoor heat exchanger. The n branches are arranged in parallel between the main inlet and the main outlet of the indoor heat exchanger, where n is a positive integer greater than or equal to 2. After the air conditioner has been running stably for a certain period (e.g., 10 minutes) in the current operating mode, with the current indoor unit fan speed and the current air guide plate position, the main inlet and outlet temperatures of the indoor heat exchanger, as well as the inlet and outlet temperatures of each of the n branches, are collected. The total temperature difference (e.g., ΔT) between the main inlet and outlet temperatures of the indoor heat exchanger is determined, and the branch temperature difference between the inlet and outlet temperatures of each branch is determined to obtain the n branch temperatures. The branch temperature differences (e.g., ΔT1, ΔT2, ΔT3, and ΔT4) are used to determine the outlet temperature difference (e.g., ΔT5) between the maximum and minimum outlet temperatures of the n branches, and the inlet temperature difference (e.g., ΔT6) between the maximum and minimum inlet temperatures of the n branches. Based on the total temperature difference (e.g., ΔT), the branch temperature differences (e.g., ΔT1, ΔT2, ΔT3, and ΔT4), the outlet temperature difference (e.g., ΔT5), and the inlet temperature difference (e.g., ΔT6), it is determined whether there is uneven refrigerant distribution in the indoor heat exchanger, and whether the uneven refrigerant distribution occurs in the heat exchanger's distributor or a specific branch. The location of the uneven refrigerant distribution is then identified, and the compressor frequency is determined based on the minimum branch temperature difference among the n branches, allowing the compressor to operate at a lower frequency, significantly reducing the risk of indoor unit frosting.

[0141] According to an embodiment of the present invention, an air conditioner corresponding to a control device for an air conditioner is also provided. This air conditioner may include the control device for an air conditioner described above.

[0142] Since the processing and functions implemented by the air conditioner in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned devices, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0143] The technical solution of this invention involves an indoor heat exchanger (e.g., an evaporator) with n inlets and n outlets in the indoor unit of an air conditioner. The main inlet of the indoor heat exchanger is connected to the n inlets of each of the n branches, and the n outlets of each of the n branches are connected to the main outlet of the indoor heat exchanger. The n branches are arranged in parallel between the main inlet and the main outlet of the indoor heat exchanger, where n is a positive integer greater than or equal to 2. After the air conditioner has been running stably for a certain period (e.g., 10 minutes) in the current operating mode, with the current indoor unit fan speed and the current air guide plate position, the main inlet and outlet temperatures of the indoor heat exchanger, as well as the inlet and outlet temperatures of each of the n branches, are collected. The total temperature difference (e.g., ΔT) between the main inlet and outlet temperatures of the indoor heat exchanger is determined, and the branch temperature difference (e.g., ΔT) between the inlet and outlet temperatures of each branch is determined to obtain the branch temperature difference (e.g., ΔT) of the n branches. Determine the outlet temperature difference (e.g., △T5) between the maximum and minimum outlet temperatures of the n branches (e.g., T1, △T2, △T3, and △T4), and the inlet temperature difference (e.g., △T6) between the maximum and minimum inlet temperatures of the n branches. Based on the total temperature difference (e.g., △T), the branch temperature differences of the n branches (e.g., △T1, △T2, △T3, and △T4), the outlet temperature difference of the n branches (e.g., △T5), and the inlet temperature difference of the n branches (e.g., △T6), determine whether there is uneven refrigerant distribution in the indoor heat exchanger, and determine whether the uneven refrigerant distribution occurs in the indoor heat exchanger's distributor or a specific branch. Provide a reminder of the location of the uneven refrigerant distribution in the indoor heat exchanger. Determine the compressor frequency based on the minimum branch temperature difference among the n branches to enable the compressor to operate at a lower frequency, thereby enhancing the reliability of the indoor unit control and reducing the risk of freezing or frosting in the indoor unit.

[0144] According to an embodiment of the present invention, a storage medium corresponding to a control method for an air conditioner is also provided, the storage medium including a stored program, wherein the program controls the device where the storage medium is located to execute the control method for the air conditioner described above when it is executed.

[0145] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0146] The technical solution of this invention involves an indoor heat exchanger (e.g., an evaporator) with n inlets and n outlets in the indoor unit of an air conditioner. The main inlet of the indoor heat exchanger is connected to the n inlets of each of the n branches, and the n outlets of each of the n branches are connected to the main outlet of the indoor heat exchanger. The n branches are arranged in parallel between the main inlet and the main outlet of the indoor heat exchanger, where n is a positive integer greater than or equal to 2. After the air conditioner has been running stably for a certain period (e.g., 10 minutes) in the current operating mode, with the current indoor unit fan speed and the current air guide plate position, the main inlet and outlet temperatures of the indoor heat exchanger, as well as the inlet and outlet temperatures of each of the n branches, are collected. The total temperature difference (e.g., ΔT) between the main inlet and outlet temperatures of the indoor heat exchanger is determined, and the branch temperature difference (e.g., ΔT) between the inlet and outlet temperatures of each branch is determined to obtain the branch temperature difference of the n branches. △T1, △T2, △T3, and △T4) are used to determine the outlet temperature difference (e.g., △T5) between the maximum and minimum outlet temperatures of the n branches, and the inlet temperature difference (e.g., △T6) between the maximum and minimum inlet temperatures of the n branches. Based on the total temperature difference (e.g., △T), the branch temperature differences of the n branches (e.g., △T1, △T2, △T3, and △T4), the outlet temperature difference of the n branches (e.g., △T5), and the inlet temperature difference of the n branches (e.g., △T6), it is determined whether there is uneven refrigerant distribution in the indoor heat exchanger, and whether the uneven refrigerant distribution occurs in the heat exchanger's distributor or a specific branch. The location of the uneven refrigerant distribution is then identified. The compressor frequency is determined based on the minimum branch temperature difference among the n branches, so that the compressor operates at a reduced frequency. By reducing the compressor's operating frequency, the possibility of freezing or frosting in the indoor unit is effectively mitigated.

[0147] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0148] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method for an air conditioner, characterized in that, The air conditioner includes an indoor heat exchanger; the indoor heat exchanger has n inlets and n outlets, where n is a positive integer greater than or equal to 2; the total inlet of the indoor heat exchanger is connected to the n inlets of the n branches, and the n outlets of the n branches are connected to the total outlet of the indoor heat exchanger. The control method for the air conditioner includes: After the air conditioner is turned on, determine the current operating mode of the air conditioner, determine the current fan speed of the indoor fan of the air conditioner, and determine the current air guide plate position of the indoor unit of the air conditioner. After the air conditioner has been running for a first set time in the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit, the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches are obtained. The temperature difference between the total inlet temperature and the total outlet temperature of the indoor heat exchanger is determined and denoted as the total temperature difference of the indoor heat exchanger; the temperature difference between the inlet temperature and the outlet temperature of each of the n branches is determined and denoted as the branch temperature difference of the n branches; the temperature difference between the maximum and minimum outlet temperatures of the n branches is determined and denoted as the outlet temperature difference of the n branches; and the temperature difference between the maximum and minimum inlet temperatures of the n branches is determined and denoted as the inlet temperature difference of the n branches. Based on the total temperature difference of the indoor heat exchanger and the branch temperature difference of the n branches, it is preliminarily determined whether the indoor heat exchanger has experienced uneven refrigerant distribution. If it is preliminarily determined that the indoor heat exchanger has an uneven refrigerant distribution, then based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in combination with the branch temperature difference of the n branches, it is further determined whether the indoor heat exchanger has an uneven refrigerant distribution. If it is further determined that the indoor heat exchanger has an uneven refrigerant distribution, then the fault location of the uneven refrigerant distribution in the indoor heat exchanger is determined, and an alert message for the fault location is initiated; and, based on the branch temperature difference of the n branches, the compressor of the air conditioner is controlled to operate at a reduced frequency.

2. The control method for an air conditioner according to claim 1, characterized in that, in, The current operating mode of the air conditioner is either cooling mode or heating mode; And / or, The current wind speed of the indoor fan is any one of the preset high wind speed, preset high wind speed, preset medium wind speed, preset low wind speed and preset silent wind speed. And / or, The indoor unit has a first air guide plate and a second air guide plate; the current air guide plate position of the indoor unit is any combination of the default combination position of the first air guide plate and the second air guide plate, the first combination position of the first air guide plate and the second air guide plate, the second combination position of the first air guide plate and the second air guide plate, the third combination position of the first air guide plate and the second air guide plate, and the fourth combination position of the first air guide plate and the second air guide plate.

3. The control method for an air conditioner according to claim 1, characterized in that, Based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches, a preliminary determination is made as to whether the indoor heat exchanger has experienced uneven refrigerant distribution, including: Based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set total temperature difference threshold, the current total temperature difference threshold of the indoor heat exchanger is determined under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set branch temperature difference threshold, the current branch temperature difference threshold of the n branches is determined under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit. Determine whether the total temperature difference of the indoor heat exchanger is less than the current total temperature difference threshold of the indoor heat exchanger: if so, it is preliminarily determined that the indoor heat exchanger has experienced uneven refrigerant distribution; Determine whether the branch temperature difference of each of the n branches is less than the current branch temperature difference threshold of the n branches: if so, it is preliminarily determined that the indoor heat exchanger has an uneven refrigerant distribution, and it is preliminarily determined that the branch has a weld blockage, and a reminder message is issued that the branch has a weld blockage.

4. The control method for an air conditioner according to claim 1, characterized in that, Based on the outlet temperature difference and inlet temperature difference of the n branches, and in conjunction with the branch temperature difference of the n branches, further determine whether the indoor heat exchanger has experienced uneven refrigerant distribution, including: Based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set outlet temperature difference threshold, the current outlet temperature difference threshold of the indoor heat exchanger is determined under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set inlet temperature difference threshold, the current inlet temperature difference threshold of the indoor heat exchanger is determined under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit. Determine whether the outlet temperature difference of the n branches is greater than the current outlet temperature difference threshold of the indoor heat exchanger. If so, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to the uneven refrigerant distribution in the n branches. Determine whether the inlet temperature difference of the n branches is greater than the current inlet temperature difference threshold of the indoor heat exchanger: if so, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution caused by the distributor of the indoor heat exchanger; otherwise, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to the uneven refrigerant distribution in the n branches.

5. The control method for an air conditioner according to claim 4, characterized in that, If it is further determined that the indoor heat exchanger has experienced refrigerant uneven distribution, then the location of the fault where the refrigerant uneven distribution has occurred is determined, and an alert message for the fault location is initiated, including: If it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the cause of the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution in the distributor of the indoor heat exchanger, then the fault location of the uneven refrigerant distribution in the indoor heat exchanger is determined to be the distributor, and an alert message for uneven refrigerant distribution in the distributor is initiated. If it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to the uneven refrigerant distribution in the n branches, then the maximum value of the branch temperature difference among the n branches is determined, the branch corresponding to the maximum value is locked as the branch with uneven refrigerant distribution, and an alert message for uneven refrigerant distribution in that branch is initiated.

6. The control method for an air conditioner according to any one of claims 1 to 5, characterized in that, Based on the branch temperature difference of the n branches, control the compressor of the air conditioner to operate at a reduced frequency, including: Determine the minimum value among the branch temperature differences of the n branches; based on the inlet and outlet temperatures of the branch corresponding to the minimum value, determine the target frequency of the air conditioner's compressor; The compressor's current frequency is reduced to the compressor's target frequency at a set rate to correct the compressor's current frequency and enable the compressor to operate at a reduced frequency. After the second set time, the current frequency of the compressor is further corrected to cause the compressor to operate at a reduced frequency; This cycle continues until the current frequency of the compressor drops to a preset minimum frequency. After the air conditioner continues to run for a third set time, if it is still determined that the indoor heat exchanger has uneven refrigerant distribution, the air conditioner is shut down.

7. A control device for an air conditioner, characterized in that, The air conditioner includes an indoor heat exchanger; the indoor heat exchanger has n inlets and n outlets, where n is a positive integer greater than or equal to 2; the total inlet of the indoor heat exchanger is connected to the n inlets of the n branches, and the n outlets of the n branches are connected to the total outlet of the indoor heat exchanger. The control device for the air conditioner includes: The control unit is configured to, after the air conditioner is turned on, determine the current operating mode of the air conditioner, determine the current fan speed of the indoor fan of the air conditioner, and determine the current air guide plate position of the indoor unit of the air conditioner. The acquisition unit is configured to acquire the total inlet temperature of the indoor heat exchanger, the total outlet temperature of the indoor heat exchanger, the inlet temperature of each of the n branches, and the outlet temperature of each of the n branches after the air conditioner has been running for a first set time in the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit. The control unit is further configured to: determine the temperature difference between the total inlet temperature and the total outlet temperature of the indoor heat exchanger, denoted as the total temperature difference of the indoor heat exchanger; determine the temperature difference between the inlet temperature and the outlet temperature of each of the n branches, denoted as the branch temperature difference of the n branches; determine the temperature difference between the maximum and minimum outlet temperatures of the n branches, denoted as the outlet temperature difference of the n branches; and determine the temperature difference between the maximum and minimum inlet temperatures of the n branches, denoted as the inlet temperature difference of the n branches. The control unit is also configured to preliminarily determine whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the total temperature difference of the indoor heat exchanger and the branch temperature difference of the n branches. The control unit is further configured to, if it is initially determined that the indoor heat exchanger has experienced uneven refrigerant distribution, further determine whether the indoor heat exchanger has experienced uneven refrigerant distribution based on the outlet temperature difference of the n branches and the inlet temperature difference of the n branches, and in combination with the branch temperature difference of the n branches. The control unit is further configured to, if it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, determine the fault location of the uneven refrigerant distribution in the indoor heat exchanger and initiate a reminder message for the fault location; and, based on the branch temperature difference of the n branches, control the compressor of the air conditioner to operate at a reduced frequency.

8. The control device for an air conditioner according to claim 7, characterized in that, in, The current operating mode of the air conditioner is either cooling mode or heating mode; And / or, The current wind speed of the indoor fan is any one of the preset high wind speed, preset high wind speed, preset medium wind speed, preset low wind speed and preset silent wind speed. And / or, The indoor unit has a first air guide plate and a second air guide plate; the current air guide plate position of the indoor unit is any combination of the default combination position of the first air guide plate and the second air guide plate, the first combination position of the first air guide plate and the second air guide plate, the second combination position of the first air guide plate and the second air guide plate, the third combination position of the first air guide plate and the second air guide plate, and the fourth combination position of the first air guide plate and the second air guide plate.

9. The control device for an air conditioner according to claim 7, characterized in that, The control unit, based on the total temperature difference of the indoor heat exchanger and the branch temperature differences of the n branches, preliminarily determines whether the indoor heat exchanger has experienced uneven refrigerant distribution, including: Based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set total temperature difference threshold, the current total temperature difference threshold of the indoor heat exchanger is determined under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set branch temperature difference threshold, the current branch temperature difference threshold of the n branches is determined under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit. Determine whether the total temperature difference of the indoor heat exchanger is less than the current total temperature difference threshold of the indoor heat exchanger: if so, it is preliminarily determined that the indoor heat exchanger has experienced uneven refrigerant distribution; Determine whether the branch temperature difference of each of the n branches is less than the current branch temperature difference threshold of the n branches: if so, it is preliminarily determined that the indoor heat exchanger has an uneven refrigerant distribution, and it is preliminarily determined that the branch has a weld blockage, and a reminder message is issued that the branch has a weld blockage.

10. The control device for an air conditioner according to claim 7, characterized in that, The control unit, based on the outlet temperature difference and inlet temperature difference of the n branches, and in conjunction with the branch temperature difference of the n branches, further determines whether the indoor heat exchanger has experienced uneven refrigerant distribution, including: Based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set outlet temperature difference threshold, the current outlet temperature difference threshold of the indoor heat exchanger is determined under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit; and based on the correspondence between the set operating mode, set fan speed, set air guide plate position, and set inlet temperature difference threshold, the current inlet temperature difference threshold of the indoor heat exchanger is determined under the current operating mode of the air conditioner, the current fan speed of the indoor fan, and the current air guide plate position of the indoor unit. Determine whether the outlet temperature difference of the n branches is greater than the current outlet temperature difference threshold of the indoor heat exchanger. If so, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to the uneven refrigerant distribution in the n branches. Determine whether the inlet temperature difference of the n branches is greater than the current inlet temperature difference threshold of the indoor heat exchanger: if so, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution caused by the distributor of the indoor heat exchanger; otherwise, further determine that the indoor heat exchanger has experienced uneven refrigerant distribution, and consider that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to the uneven refrigerant distribution in the n branches.

11. The control device for an air conditioner according to claim 10, characterized in that, If the control unit further determines that the indoor heat exchanger has experienced refrigerant uneven distribution, it determines the fault location of the refrigerant uneven distribution in the indoor heat exchanger and initiates a fault location alert message, including: If it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the cause of the uneven refrigerant distribution in the indoor heat exchanger is due to uneven refrigerant distribution in the distributor of the indoor heat exchanger, then the fault location of the uneven refrigerant distribution in the indoor heat exchanger is determined to be the distributor, and an alert message for uneven refrigerant distribution in the distributor is initiated. If it is further determined that the indoor heat exchanger has experienced uneven refrigerant distribution, and it is believed that the reason for the uneven refrigerant distribution in the indoor heat exchanger is due to the uneven refrigerant distribution in the n branches, then the maximum value of the branch temperature difference among the n branches is determined, the branch corresponding to the maximum value is locked as the branch with uneven refrigerant distribution, and an alert message for uneven refrigerant distribution in that branch is initiated.

12. The control device for an air conditioner according to any one of claims 7 to 11, characterized in that, The control unit controls the compressor of the air conditioner to operate at a reduced frequency based on the temperature difference between the n branches, including: Determine the minimum value among the branch temperature differences of the n branches; based on the inlet and outlet temperatures of the branch corresponding to the minimum value, determine the target frequency of the air conditioner's compressor; The compressor's current frequency is reduced to the compressor's target frequency at a set rate to correct the compressor's current frequency and enable the compressor to operate at a reduced frequency. After the second set time, the current frequency of the compressor is further corrected to cause the compressor to operate at a reduced frequency; This cycle continues until the current frequency of the compressor drops to a preset minimum frequency. After the air conditioner continues to run for a third set time, if it is still determined that the indoor heat exchanger has uneven refrigerant distribution, the air conditioner is shut down.

13. An air conditioner, characterized in that, include: The control device for an air conditioner as described in any one of claims 7 to 12.

14. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method of the air conditioner according to any one of claims 1 to 6.

Images