Indoor unit anti-condensation control method and device, and multi-connected air conditioner

Abstract

The application provides a control method and device for indoor unit anti-condensation and a multi-connected air conditioner. The method comprises: obtaining an operating parameter when the multi-connected air conditioner is in refrigeration operation; determining whether the multi-connected air conditioner meets a preset anti-condensation condition according to the operating parameter; if yes, controlling the multi-connected air conditioner to enter an anti-condensation mode, and in the anti-condensation mode, controlling the multi-connected air conditioner to execute according to a specified action to prevent the indoor unit from producing condensation. In the control mode, whether the multi-connected air conditioner is in a condensation-prone state, i.e. the preset anti-condensation condition, is determined according to the operating parameter. If yes, the multi-connected air conditioner is controlled to execute according to the specified action to reduce the amount of refrigerant entering the indoor unit, thereby avoiding the indoor unit from producing condensation and ensuring the air conditioning comfort of the user.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a control method and device for preventing condensation in indoor units and a multi-split air conditioner. Background Technology

[0002] In practical applications, multi-split air conditioners typically use one outdoor unit to power multiple indoor units. This results in a situation where, when only one indoor unit is operating, the demand is too low, the fan speed is low, the convective heat transfer coefficient is low, and the heat exchange effect is poor. Meanwhile, the outdoor unit's output is relatively high. In cooling mode, due to Q... 冷媒 >Q 换热 (Q 冷媒 Q: The amount of heat absorbed by the refrigerant in the evaporator per unit time; 换热 Insufficient heat exchange in the evaporator per unit time will result in incomplete evaporation of the refrigerant entering the indoor unit, leading to low superheat and low pressure in the indoor unit. This can cause the compressor to be at risk of liquid return. Furthermore, the low temperature of the refrigerant after circulation in the indoor unit's evaporator will result in low air outlet temperature, which will cause condensation and dripping at low speeds, affecting user comfort. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a control method, device and multi-split air conditioner for preventing condensation in indoor units, so as to alleviate the above-mentioned technical problems, reduce the amount of refrigerant entering the indoor unit in the multi-split air conditioner, thereby avoiding condensation in the indoor unit and ensuring the user's air conditioning comfort.

[0004] In a first aspect, embodiments of the present invention provide a control method for preventing condensation in an indoor unit, applied to a multi-split air conditioner; the method includes: when the multi-split air conditioner is running in cooling mode, acquiring operating parameters; wherein, the operating parameters include: low-pressure temperature, and the corresponding indoor relative humidity, dew point temperature, outlet air temperature, and running time of the indoor unit, the running time being used to characterize the duration of continuous operation of the indoor unit at low fan speed; determining whether the multi-split air conditioner meets preset anti-condensation conditions based on the operating parameters; if so, controlling the multi-split air conditioner to enter an anti-condensation mode, and in the anti-condensation mode, controlling the multi-split air conditioner to perform specified actions to prevent condensation from occurring in the indoor unit; wherein, the specified actions include at least one of the following: valve opening adjustment, compressor frequency reduction, indoor unit fan speed fluctuation operation, and liquid tank status control.

[0005] The above-mentioned indoor unit anti-condensation control method determines whether the multi-split air conditioner is in a state prone to condensation, i.e., presets anti-condensation conditions, based on the operating parameters of the multi-split air conditioner during cooling operation. If so, the multi-split air conditioner is controlled to perform specified actions to reduce the amount of refrigerant entering the indoor unit and increase the inlet pipe temperature of the refrigerant in the indoor unit, thereby preventing condensation from occurring in the indoor unit and ensuring the user's air conditioning comfort.

[0006] Preferably, the aforementioned preset anti-condensation conditions include preset parameters; wherein, the preset parameters include: a first preset duration, a second preset duration, a third preset duration, a preset temperature difference threshold, a preset humidity threshold, and a preset target low-pressure temperature; the step of determining whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters includes: ① determining whether the operating duration reaches the first preset duration; ② determining whether the difference between the dew point temperature and the outlet air temperature is not less than the preset temperature difference threshold, and the duration reaches the second preset duration; ③ determining whether the indoor relative humidity is not less than the preset humidity threshold; ④ determining whether the low-pressure temperature is less than the preset target low-pressure temperature, and the duration reaches the third preset duration; if all of the above ①-④ are true, then the multi-split air conditioner is determined to meet the preset anti-condensation conditions.

[0007] Preferably, the steps for controlling the multi-split air conditioner to perform specified actions include: controlling the indoor unit's fan to operate periodically according to a preset speed sequence during indoor unit fan speed fluctuation operation; wherein, the preset speed sequence includes a first speed, a second speed, and a third speed set sequentially, and the first speed, the second speed, and the third speed are all different.

[0008] Preferably, an inlet solenoid valve and an outlet solenoid valve are respectively installed at the inlet and outlet of the liquid storage tank; the steps for controlling the multi-split air conditioner to perform the specified actions include: in the state control of the liquid storage tank, obtaining the pressure in the liquid storage tank; if the pressure is less than a preset pressure threshold, controlling the inlet solenoid valve to open and controlling the outlet solenoid valve to close, so that the liquid storage tank is in the working state; if the pressure is not less than the preset pressure threshold, controlling both the inlet solenoid valve and the outlet solenoid valve to close, so that the liquid storage tank is in the non-working state.

[0009] Preferably, the above method further includes: obtaining the first indoor unit demand and the second indoor unit demand of the multi-split air conditioner; wherein, the first indoor unit demand is used to characterize the total indoor unit demand when the multi-split air conditioner enters the anti-condensation mode, and the second indoor unit demand is used to characterize the indoor unit demand when the multi-split air conditioner is running in the anti-condensation mode; determining whether the second indoor unit demand is not greater than the first indoor unit demand; if so, controlling the multi-split air conditioner to continue operating in the anti-condensation mode.

[0010] Preferably, the above method further includes: if the demand of the second indoor unit is greater than that of the first indoor unit, then controlling the multi-split air conditioner to exit the anti-condensation mode.

[0011] Preferably, the above method further includes: if the multi-split air conditioner does not meet the preset anti-condensation conditions, controlling the multi-split air conditioner to continue cooling operation.

[0012] Secondly, embodiments of the present invention also provide a control device for preventing condensation in an indoor unit, applied to a multi-split air conditioner; the device includes: an acquisition module, used to acquire operating parameters when the multi-split air conditioner is in cooling operation; wherein, the operating parameters include: low-pressure temperature, and the indoor relative humidity, dew point temperature, outlet air temperature, and operating time corresponding to the indoor unit, the operating time being used to characterize the duration of continuous operation of the indoor unit at low fan speed; a judgment module, used to determine whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters; an execution module, used to control the multi-split air conditioner to enter the anti-condensation mode if so, and in the anti-condensation mode, control the multi-split air conditioner to perform specified actions to prevent condensation from occurring in the indoor unit; wherein, the specified actions include at least one of the following: valve opening adjustment, compressor frequency reduction, indoor unit fan speed fluctuation operation, and liquid tank status control.

[0013] Thirdly, embodiments of the present invention also provide a multi-split air conditioner, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the indoor unit anti-condensation control method described in the first aspect.

[0014] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, performs the steps of the indoor unit anti-condensation control method described in the first aspect.

[0015] The embodiments of the present invention bring the following beneficial effects:

[0016] This invention provides a control method, device, and multi-split air conditioner for preventing condensation in indoor units. Based on the operating parameters of the multi-split air conditioner during cooling operation, it determines whether the air conditioner is in a state prone to condensation, i.e., a preset anti-condensation condition. If so, the multi-split air conditioner is controlled to perform specified actions to reduce the amount of refrigerant entering the indoor unit and increase the inlet pipe temperature of the refrigerant in the indoor unit, thereby preventing condensation in the indoor unit and ensuring the user's air conditioning comfort.

[0017] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A flowchart of a control method for preventing condensation in an indoor unit, provided as an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of a multi-split air conditioner provided in an embodiment of the present invention;

[0022] Figure 3 A flowchart of another indoor unit anti-condensation control method provided in an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of an indoor unit anti-condensation control device provided in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of another multi-split air conditioner provided in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] To address the problem of condensation easily occurring in indoor units of existing multi-split air conditioners when the load demand is low or the indoor environment temperature and humidity are high, this invention provides a control method, device, and multi-split air conditioner for preventing condensation in the indoor unit. Based on the operating parameters of the multi-split air conditioner during cooling operation, it determines whether the air conditioner is in a condensation-prone state, i.e., presets anti-condensation conditions. If so, the multi-split air conditioner is controlled to perform specified actions to reduce the amount of refrigerant entering the indoor unit and increase the inlet pipe temperature of the refrigerant in the indoor unit, thereby preventing condensation in the indoor unit and ensuring the user's air conditioning comfort.

[0027] To facilitate understanding of this embodiment, the embodiments of the present invention will be described in detail below.

[0028] Example 1:

[0029] This invention provides a control method for preventing condensation in indoor units, applicable to multi-split air conditioners. The multi-split air conditioner includes multiple indoor units and at least one outdoor unit. The specific number of indoor and outdoor units can be set according to actual conditions. Furthermore, during operation of the multi-split air conditioner, the number of outdoor or indoor units that can be turned on can be set according to actual conditions; this invention does not impose any limitations on this.

[0030] For ease of explanation, this embodiment of the invention uses any operating indoor unit as an example. The anti-condensation control process of other indoor units can be referenced from that indoor unit, and will not be described in detail here. Figure 1 As shown, the indoor unit's anti-condensation control method includes the following steps:

[0031] Step S102: When the multi-split air conditioner is in cooling mode, obtain the operating parameters;

[0032] Specifically, when the multi-split air conditioner is running in cooling mode, the operating parameters at that time are acquired; these operating parameters include: low-pressure temperature Ps, and the indoor relative humidity RH and dew point temperature T corresponding to the indoor unit. d Air outlet temperature T f and runtime t 运行 The runtime here is t. 运行 This is used to characterize the duration of continuous operation of the indoor unit at the low fan speed. For example, if the indoor unit's fan has high, medium, and low fan speeds, then the operating time t is... 运行 This refers to the duration the indoor unit's fan operates continuously at its lowest setting. It should be noted that if the fan speed is adjusted proportionally, this running time t... 运行 It also allows you to set the duration for which the indoor unit's fan runs continuously at a speed below a preset threshold. Speeds below the preset threshold are referred to as low speeds. The preset threshold can be set according to actual conditions.

[0033] In addition, regarding the aforementioned dew point temperature T d It can be calculated using the Maglas formula, which is as follows:

[0034]

[0035] According to the above formula (1), the dew point temperature T can be obtained. d The calculation formula is as follows:

[0036]

[0037] In formulas (1) and (2) above, E represents the actual water vapor pressure, in hPa, and E = saturated water vapor pressure at the corresponding temperature (which can be obtained from the thermodynamic property curve of water and water vapor) × indoor relative humidity RH; E0 represents the saturated water vapor pressure at 0℃, which can be taken as 61.12 hPa; a represents a coefficient, preferably 7.69; b also represents a coefficient, preferably 243.92; therefore, the dew point temperature T corresponding to the indoor unit can be calculated according to formula (2). d .

[0038] In addition, regarding the outlet air temperature T f One method of obtaining the temperature is to install a temperature sensor or temperature sensor at the air outlet of the indoor unit, and then use the sensor or temperature sensor to detect the air outlet temperature T of the indoor unit in real time. f Another method is to obtain the refrigerant inlet pipe temperature, refrigerant outlet pipe temperature, and calculation coefficient of the indoor unit, and then calculate the outlet air temperature T based on the refrigerant inlet pipe temperature, refrigerant outlet pipe temperature, and calculation coefficient. f Among them, the outlet air temperature T f The calculation formula is as follows:

[0039]

[0040] Among them, T f Indicates the outlet air temperature, T c T represents the refrigerant outlet temperature. r This indicates the refrigerant inlet pipe temperature, and m represents the calculation coefficient, which can be set according to the type of indoor unit.

[0041] Furthermore, the low-pressure temperature Ps and indoor relative humidity RH can be obtained through corresponding detection devices, which will not be described in detail here.

[0042] Step S104: Determine whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters;

[0043] After obtaining the operating parameters of the multi-split air conditioner during cooling operation, the controller of the multi-split air conditioner also determines whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters, that is, whether the indoor unit is in a state prone to condensation. In order to control the multi-split air conditioner in a timely manner when the anti-condensation conditions are met, so as to avoid condensation in the indoor unit and thus ensure the user's air conditioning comfort.

[0044] Step S106: If yes, control the multi-split air conditioner to enter the anti-condensation mode, and in the anti-condensation mode, control the multi-split air conditioner to perform the specified actions to prevent condensation from occurring in the indoor unit.

[0045] When a multi-split air conditioner enters anti-condensation mode, the control unit performs specified actions. These specified actions include at least one of the following: valve opening adjustment, compressor frequency reduction, indoor unit fan speed fluctuation operation, and liquid receiver status control. Through one or more specified actions, the multi-split air conditioner is intelligently adjusted to reduce the output of the outdoor unit and decrease the amount of refrigerant entering the indoor unit, thereby preventing condensation from forming in the indoor unit.

[0046] The indoor unit anti-condensation control method provided in this embodiment of the invention determines whether the multi-split air conditioner is in a state prone to condensation, i.e., presets anti-condensation conditions, based on the operating parameters of the multi-split air conditioner during cooling operation. If so, the multi-split air conditioner is controlled to perform specified actions to reduce the amount of refrigerant entering the indoor unit and increase the inlet pipe temperature of the refrigerant in the indoor unit, thereby preventing condensation from occurring in the indoor unit and ensuring the user's air conditioning comfort.

[0047] In one embodiment, the aforementioned preset anti-condensation conditions include preset parameters; wherein, the preset parameters include: a first preset duration t1, a second preset duration t2, a third preset duration t3, a preset temperature difference threshold ΔT, a preset humidity threshold RH0, and a preset target low-pressure temperature Psmin; here, the preset target low-pressure temperature Psmin is the target minimum low-pressure temperature of the multi-split air conditioner, and the specific value can be set according to the actual situation.

[0048] Specifically, the process of determining whether a multi-split air conditioner meets the preset anti-condensation conditions based on operating parameters includes:

[0049] ① Determine whether the running time has reached the first preset duration; that is, determine the running time t of the indoor unit running continuously at low speed. 运行 Does it satisfy: t 运行 ≥t1;

[0050] ② Determine whether the difference between the dew point temperature and the outlet air temperature is not less than a preset temperature difference threshold, and whether the duration reaches a second preset duration; that is, determine whether the following condition is met: T d -T f ≥△T, and duration ≥t2;

[0051] ③ Determine whether the indoor relative humidity is not less than the preset humidity threshold; that is, determine whether the following condition is met: RH≥RH0;

[0052] ④ Determine whether the low-pressure temperature is less than the preset target low-pressure temperature and whether the duration reaches the third preset duration; that is, determine whether the following conditions are met: Ps < Psmin and duration ≥ t3.

[0053] If all of ①-④ above are true, then the multi-split air conditioner is determined to meet the preset anti-condensation conditions; otherwise, if at least one of ①-④ above is false, then the multi-split air conditioner is determined not to meet the preset anti-condensation conditions.

[0054] It should be noted that, under the premise of low indoor unit speed, when the dew point temperature is 5°C higher than the outlet air temperature and RH≥60%, condensation is very likely to form in the indoor unit; and, when the indoor unit speed is low, the heat exchange effect of the evaporator of the indoor unit is poor, which will lead to a lower outlet air temperature (other selection conditions are more complex and are not considered in this embodiment of the invention). Therefore, the above-mentioned preset temperature difference threshold △T is preferably 5°C, the preset humidity threshold RH0 is preferably 60%, and the first preset duration t1 is preferably 60 min, the second preset duration t2 is preferably 60 min, and the third preset duration t3 is preferably 30 min. The specific values ​​of △T, RH0, t1, t2 and t3 can be adjusted adaptively according to the actual situation.

[0055] In one implementation, when the multi-split air conditioner meets the preset anti-condensation conditions, the multi-split air conditioner is controlled to enter the anti-condensation mode, and in the anti-condensation mode, the multi-split air conditioner is controlled to perform specified actions. The specified actions include at least one of the following: valve opening adjustment, compressor frequency reduction, indoor unit fan speed fluctuation operation, and liquid receiver status control.

[0056] To facilitate understanding, the execution process of each specified action will be explained here, taking into account the specific structure of a multi-split air conditioner. For example, Figure 2 The multi-split air conditioner includes, but is not limited to, a first compressor 11, a second compressor 12, an oil separator 13, a first gas-liquid separator 14, a second gas-liquid separator 15, a solenoid valve 16, an electronic expansion valve 17, and a liquid receiver 18. Here, the solenoid valve 16 can also be called a gas bypass solenoid valve. Furthermore, an inlet solenoid valve 181 and an outlet solenoid valve 182 are respectively provided at the inlet and outlet of the liquid receiver 18. It should be noted that the specific structure of the multi-split air conditioner can refer to existing multi-split air conditioners, and the embodiments of this invention will not be described in detail here.

[0057] Specifically, the execution process of a multi-split air conditioner according to each specified action is as follows:

[0058] (1) Valve opening adjustment: Control solenoid valve 16 to be in the normally open state so that the high temperature and high pressure gas from oil separator 13 can re-enter the first gas-liquid separator 14 and the second gas-liquid separator 15, thereby increasing the initial temperature of the refrigerant absorbed by the first compressor 11 and the second compressor 12, and thus increasing the low pressure temperature.

[0059] Simultaneously, the electronic expansion valve 17 is closed to increase the outlet pipe temperature and outlet air temperature of the indoor unit, thereby increasing the superheat of the indoor unit. In practical applications, when the electronic expansion valve 17 is open, the refrigerant flow is as follows: Figure 2 As shown by the solid arrow, the refrigerant in the main pipe flows into the small valve 19, and a portion of the refrigerant enters the liquid pipe. Because the electronic expansion valve 17 is open, it throttles and cools the liquid pipe, lowering its temperature. After heat exchange between the refrigerant in the main pipe and the liquid pipe, the temperature of the main pipe decreases, meaning the outlet pipe temperature of the indoor unit decreases. When the electronic expansion valve 17 is closed, the refrigerant flows directly from the main pipe into the small valve 19 without heat exchange. The refrigerant flow path at this time is as follows. Figure 2 As indicated by the dashed arrow, this results in a higher outlet pipe temperature for the indoor unit. Therefore, to reduce refrigerant circulation and increase the outlet pipe temperature of the indoor unit to reduce the risk of condensation, the electronic expansion valve 17 needs to be closed.

[0060] Therefore, by controlling the solenoid valve 16 to be in the normally open state and the electronic expansion valve 17 to be closed, the refrigerant circulation in the multi-split air conditioner and the evaporator is reduced, the outlet pipe temperature of the indoor unit is increased, and condensation is avoided in the indoor unit.

[0061] (2) Compressor frequency decreases: Specifically, according to F n =F n-1 -t 降频 *d reduces the compressor frequency, where F n F represents the compressor frequency at the current moment. n-1 t represents the compressor frequency at the previous moment. 降频 The frequency reduction period is represented by d, which is preferably 1 hour; d represents the compressor frequency reduction coefficient, which ranges from 1 Hz to 6 Hz, preferably 5 Hz, that is, the compressor is controlled to reduce the frequency by 5 Hz per cycle.

[0062] Therefore, reducing the compressor frequency decreases the refrigerant flow rate in the multi-split air conditioner, thereby reducing the amount of refrigerant entering the indoor unit. This leads to increased superheat in the indoor unit, higher outlet pipe temperature, and consequently, a rise in the low-pressure temperature. Specifically, if the low-pressure temperature range is increased—for example, assuming the original low-pressure temperature control range is (T1, T2), and the revised range is (T1+3, T1+5, T1+7, ..., T2+3, T2+5, T2+7, ...)—the compressor frequency will be further reduced. This decreases refrigerant circulation within the multi-split air conditioner and evaporator, further increasing the outlet pipe temperature of the indoor unit and preventing condensation.

[0063] (3) Fluctuation of indoor unit fan speed: Specifically, in normal control, if the speed of the fan in the indoor unit is F1, condensation is likely to occur when the indoor unit is kept running at a low fan speed for a long time. Therefore, the risk of condensation in multi-split air conditioners can be prevented by adjusting the fan speed.

[0064] In the case of fluctuating indoor unit fan speed, the indoor unit fan is controlled to run periodically according to a preset speed sequence. The preset speed sequence includes a first speed, a second speed, and a third speed set sequentially, and the first speed, the second speed, and the third speed are all different.

[0065] Preferably, the first rotational speed is F1 = Arps, the second rotational speed is F2 = (A+B)rps, and the third rotational speed is F3 = (A+C)rps. The values ​​of A, B, and C can be set according to actual conditions. Therefore, during the fluctuating operation of the indoor unit's fan speed, the indoor unit's fan is controlled to operate periodically according to the sequence F1-F2-F3, and the operating time of each rotational speed is a preset duration, which can be set according to actual conditions.

[0066] Furthermore, the aforementioned fan speed fluctuation control will only reduce the low pressure of the multi-split air conditioner. The multi-split air conditioner will automatically adjust to address the instability caused by the fluctuating operation of the indoor fan to the outdoor unit. Therefore, the aforementioned indoor fan speed fluctuation operation can not only prevent the risk of condensation in the multi-split air conditioner, but also will not affect the stable operation of the multi-split air conditioner.

[0067] (4) Status control of the storage tank: In the status control of the storage tank, the pressure in the storage tank is obtained. If the pressure is less than the preset pressure threshold, the inlet solenoid valve is opened and the outlet solenoid valve is closed so that the storage tank is in working state. If the pressure is not less than the preset pressure threshold, both the inlet solenoid valve and the outlet solenoid valve are closed so that the storage tank is in non-working state.

[0068] Specifically, a pressure sensor (not shown) is added between the inlet solenoid valve 181 and the liquid receiver 18 to detect the pressure P0 inside the liquid receiver 18. When the pressure is less than a preset pressure threshold (preferably 50 bar), i.e., P0 < 50 bar, the inlet solenoid valve 181 is opened and the outlet solenoid valve 182 is closed, so that the liquid receiver 18 is in working condition. At this time, the refrigerant is diverted and a certain amount of refrigerant is stored in the liquid receiver 18, thereby reducing the amount of refrigerant entering the indoor unit. When the pressure is not less than the preset pressure threshold, i.e., P0 ≥ 50 bar, it indicates that the liquid receiver 18 has reached its limit and can no longer be charged with refrigerant. At this time, both the inlet solenoid valve 181 and the outlet solenoid valve 182 are closed, so that the liquid receiver 18 is in non-working condition and the refrigerant in the multi-split air conditioner circulates normally.

[0069] Furthermore, when the multi-split air conditioner exits the anti-condensation mode, the control outlet solenoid valve 182 opens to release the refrigerant from the receiver 18. Therefore, by controlling the state of the receiver 18, the amount of refrigerant entering the indoor unit is reduced, thereby increasing the inlet pipe temperature of the refrigerant in the indoor unit, preventing condensation, and ensuring user comfort.

[0070] In one embodiment, the method further includes: obtaining a first indoor unit demand and a second indoor unit demand of the multi-split air conditioner; wherein the first indoor unit demand is used to characterize the total indoor unit demand when the multi-split air conditioner enters the anti-condensation mode, and the second indoor unit demand is used to characterize the indoor unit demand when the multi-split air conditioner is running in the anti-condensation mode; determining whether the second indoor unit demand is not greater than the first indoor unit demand; if so, controlling the multi-split air conditioner to continue operating in the anti-condensation mode.

[0071] Specifically, the total indoor unit demand when the multi-split air conditioner enters anti-condensation mode is obtained, i.e., the first indoor unit demand N1. While the multi-split air conditioner is running in anti-condensation mode, the indoor unit demand at this time, i.e., the second indoor unit demand N2, is detected in real time. If the second indoor unit demand is not greater than the first indoor unit demand, i.e., N2≤N1, it indicates that the indoor unit demand in the multi-split air conditioner has not changed. At this time, the multi-split air conditioner is controlled to continue operating in anti-condensation mode. Conversely, if the second indoor unit demand is greater than the first indoor unit demand, i.e., N2>N1, it indicates that the indoor unit demand in the multi-split air conditioner has changed. At this time, the multi-split air conditioner is controlled to exit anti-condensation mode, and the operating parameters are re-obtained so as to re-determine whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters, thereby avoiding condensation in the indoor unit when the indoor unit demand changes.

[0072] In one embodiment, the method further includes: if the multi-split air conditioner does not meet the preset anti-condensation conditions, controlling the multi-split air conditioner to continue cooling operation. Specifically, when it is determined from the operating parameters that the multi-split air conditioner does not meet the preset anti-condensation conditions, this indicates that the multi-split air conditioner is not in a state prone to condensation, so the multi-split air conditioner is controlled to continue cooling operation to meet the user's cooling needs.

[0073] Example 2:

[0074] Based on the above method embodiments, this invention also provides another method for controlling condensation prevention in indoor units, such as... Figure 3 As shown, the method includes the following steps:

[0075] Step S302: When the multi-split air conditioner is in cooling mode, acquire the operating parameters; wherein, the operating parameters include: low-pressure temperature Ps, and the indoor relative humidity RH and refrigerant outlet pipe temperature T corresponding to the indoor unit. c Refrigerant inlet pipe temperature T rThe first internal machine requirement N1 and runtime t 运行 ,

[0076] Step S304, calculate the dew point temperature: Calculate the outlet air temperature: The specific calculation process can be referred to the foregoing embodiments, and the embodiments of the present invention will not be described in detail here;

[0077] Step S306, determine whether the following condition is met: ①t 运行 ≥t1; ②T d -T f ≥5℃, and duration ≥t2; ③RH≥RH0; ④Ps<Psmin, and duration ≥t3; If so, proceed to step S308, otherwise proceed to step S312.

[0078] Step S308: Control the multi-split air conditioner to perform at least one of the following: ① Solenoid valve 16 is normally open, and electronic expansion valve 17 is closed; ② The indoor unit fan runs periodically in the sequence F1-F2-F3; ③ For the liquid receiver 18, when P0 < 50 bar, the inlet solenoid valve 181 is open and the outlet solenoid valve 182 is closed; when P0 ≥ 50 bar, the inlet solenoid valve 181 is closed; ④ Reduce the compressor frequency and increase the low-pressure temperature range; For details, please refer to the aforementioned embodiments, and the embodiments of the present invention will not be described in detail here;

[0079] Step S310; Determine if N2 > N1; where N2 is the indoor unit requirement of the multi-split air conditioner when operating in anti-condensation mode. If yes, proceed to step S312; otherwise, return to step S308.

[0080] Step S312: Perform cooling operation.

[0081] In summary, the indoor unit anti-condensation control method provided by this embodiment of the invention determines whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters of the multi-split air conditioner during cooling operation. If so, the multi-split air conditioner is intelligently adjusted through specified actions to reduce the amount of refrigerant entering the indoor unit and increase the inlet pipe temperature of the refrigerant in the indoor unit, thereby preventing condensation from occurring in the indoor unit and ensuring the user's air conditioning comfort.

[0082] Example 3:

[0083] Corresponding to the above method embodiments, this invention also provides an indoor unit anti-condensation control device, applied to multi-split air conditioners; such as Figure 4 As shown, the device includes: an acquisition module 41, a judgment module 42, and an execution module 43; wherein the functions of each module are as follows:

[0084] The acquisition module 41 is used to acquire operating parameters when the multi-split air conditioner is in cooling mode; the operating parameters include: low pressure temperature, and the indoor relative humidity, dew point temperature, air outlet temperature and running time corresponding to the indoor unit. The running time is used to characterize the duration for which the indoor unit runs continuously at low fan speed.

[0085] Judgment module 42 is used to determine whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters;

[0086] The execution module 43 is used to control the multi-split air conditioner to enter the anti-condensation mode if the condition is met, and to control the multi-split air conditioner to perform specified actions in the anti-condensation mode to prevent condensation from occurring in the indoor unit; wherein the specified actions include at least one of the following: valve opening adjustment, compressor frequency reduction, indoor unit fan speed fluctuation operation, and liquid tank status control.

[0087] The indoor unit anti-condensation control device provided in this embodiment of the invention determines whether the multi-split air conditioner is in a state prone to condensation, i.e., presets anti-condensation conditions, based on the operating parameters of the multi-split air conditioner during cooling operation. If so, it controls the multi-split air conditioner to perform specified actions to reduce the amount of refrigerant entering the indoor unit and increase the inlet pipe temperature of the refrigerant in the indoor unit, thereby preventing condensation from occurring in the indoor unit and ensuring the user's air conditioning comfort.

[0088] Preferably, the aforementioned preset anti-condensation conditions include preset parameters; wherein, the preset parameters include: a first preset duration, a second preset duration, a third preset duration, a preset temperature difference threshold, a preset humidity threshold, and a preset target low-pressure temperature; the judgment module 42 is further used to: ① determine whether the running time has reached the first preset duration; ② determine whether the difference between the dew point temperature and the outlet air temperature is not less than the preset temperature difference threshold, and the duration has reached the second preset duration; ③ determine whether the indoor relative humidity is not less than the preset humidity threshold; ④ determine whether the low-pressure temperature is less than the preset target low-pressure temperature, and the duration has reached the third preset duration; if all of the above ①-④ are true, then the multi-split air conditioner is determined to meet the preset anti-condensation conditions.

[0089] Preferably, the above-mentioned control of the multi-split air conditioner to perform a specified action includes: controlling the indoor unit's fan to operate periodically according to a preset speed sequence during indoor unit fan speed fluctuation operation; wherein, the preset speed sequence includes a first speed, a second speed, and a third speed set sequentially, and the first speed, the second speed, and the third speed are all different.

[0090] Preferably, an inlet solenoid valve and an outlet solenoid valve are respectively installed at the inlet and outlet of the liquid storage tank; the above-mentioned control of the multi-split air conditioner to perform specified actions includes: in the state control of the liquid storage tank, obtaining the pressure in the liquid storage tank; if the pressure is less than a preset pressure threshold, controlling the inlet solenoid valve to open and controlling the outlet solenoid valve to close, so that the liquid storage tank is in the working state; if the pressure is not less than the preset pressure threshold, controlling both the inlet solenoid valve and the outlet solenoid valve to close, so that the liquid storage tank is in the non-working state.

[0091] Preferably, the above-mentioned device further includes: acquiring a first indoor unit demand and a second indoor unit demand of the multi-split air conditioner; wherein, the first indoor unit demand is used to characterize the total indoor unit demand when the multi-split air conditioner enters the anti-condensation mode, and the second indoor unit demand is used to characterize the indoor unit demand when the multi-split air conditioner is running in the anti-condensation mode; determining whether the second indoor unit demand is not greater than the first indoor unit demand; if so, controlling the multi-split air conditioner to continue operating in the anti-condensation mode.

[0092] Preferably, the above-mentioned device further includes: if the demand of the second indoor unit is greater than that of the first indoor unit, then controlling the multi-split air conditioner to exit the anti-condensation mode.

[0093] Preferably, the above-mentioned device further includes: if the multi-split air conditioner does not meet the preset anti-condensation conditions, controlling the multi-split air conditioner to continue cooling operation.

[0094] The indoor unit anti-condensation control device provided in this embodiment of the invention has the same technical features as the indoor unit anti-condensation control method provided in the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0095] This invention also provides a multi-split air conditioner, including a processor and a memory. The memory stores machine-executable instructions that can be executed by the processor. The processor executes the machine-executable instructions to implement the above-mentioned indoor unit anti-condensation control method.

[0096] See Figure 5 As shown, the multi-split air conditioner includes a processor 100 and a memory 101. The memory 101 stores machine-executable instructions that can be executed by the processor 100. The processor 100 executes the machine-executable instructions to implement the above-mentioned indoor unit anti-condensation control method.

[0097] Furthermore, Figure 5 The multi-split air conditioner shown also includes a bus 102 and a communication interface 103. The processor 100, the communication interface 103 and the memory 101 are connected via the bus 102.

[0098] The memory 101 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 103 (which can be wired or wireless), such as the Internet, wide area network, local area network, or metropolitan area network. The bus 102 may be an ISA (Industrial Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Enhanced Industry Standard Architecture) bus. These buses can be categorized as address buses, data buses, and control buses. For ease of representation, Figure 5 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0099] Processor 100 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 100 or by instructions in software form. Processor 100 may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a readily available storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory 101, and the processor 100 reads the information from memory 101 and, in conjunction with its hardware, completes the steps of the method described in the foregoing embodiments.

[0100] This embodiment also provides a machine-readable storage medium storing machine-executable instructions. When the machine-executable instructions are called and executed by a processor, the machine-executable instructions cause the processor to implement the above-mentioned indoor unit anti-condensation control method.

[0101] The indoor unit anti-condensation control method, device, and computer program product for multi-split air conditioners provided in the embodiments of the present invention include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementation, please refer to the method embodiments, which will not be repeated here.

[0102] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and apparatus described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0103] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0104] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0105] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0106] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control method for preventing condensation in an indoor unit, applied to a multi-split air conditioner; characterized in that, The method includes: When the multi-split air conditioner is in cooling mode, operating parameters are acquired; wherein, the operating parameters include: low pressure temperature, and the indoor relative humidity, dew point temperature, air outlet temperature and operating time corresponding to the indoor unit, wherein the operating time is used to characterize the duration for which the indoor unit continuously operates at low fan speed; Determine whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters; If so, control the multi-split air conditioner to enter the anti-condensation mode, and in the anti-condensation mode, control the multi-split air conditioner to perform specified actions to prevent condensation from occurring in the indoor unit; wherein, the specified actions include at least one of the following: valve opening adjustment, compressor frequency reduction, indoor unit fan speed fluctuation operation, and liquid tank status control; The preset anti-condensation conditions include preset parameters; wherein, the preset parameters include: a first preset duration, a second preset duration, a third preset duration, a preset temperature difference threshold, a preset humidity threshold, and a preset target low-pressure temperature; the step of determining whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters includes: ① Determine whether the running time has reached the first preset time; ② Determine whether the difference between the dew point temperature and the outlet air temperature is not less than the preset temperature difference threshold, and whether the duration reaches the second preset duration; ③ Determine whether the indoor relative humidity is not less than the preset humidity threshold; ④ Determine whether the low-pressure temperature is lower than the preset target low-pressure temperature, and whether the duration reaches the third preset duration; If all of the above ①-④ are true, then the multi-split air conditioner is determined to meet the preset anti-condensation conditions.

2. The method of claim 1, wherein, The steps for controlling the multi-split air conditioner to perform specified actions include: During the fluctuating operation of the indoor unit's fan speed, the fan of the indoor unit is controlled to operate periodically according to a preset speed sequence; wherein, the preset speed sequence includes a first speed, a second speed, and a third speed set sequentially, and the first speed, the second speed, and the third speed are all different.

3. The method of claim 1, wherein, An inlet solenoid valve and an outlet solenoid valve are respectively installed at the inlet and outlet of the liquid storage tank; the steps for controlling the multi-split air conditioner to perform specified actions include: In the state control of the liquid storage tank, the pressure in the liquid storage tank is obtained. If the pressure is less than a preset pressure threshold, the inlet solenoid valve is opened and the outlet solenoid valve is closed to put the liquid storage tank into a working state. If the pressure is not less than the preset pressure threshold, both the inlet solenoid valve and the outlet solenoid valve are closed to put the liquid storage tank into a non-working state.

4. The method according to claim 1, characterized in that, The method further includes: Obtain the first indoor unit demand and the second indoor unit demand of the multi-split air conditioner; wherein, the first indoor unit demand is used to characterize the total indoor unit demand when the multi-split air conditioner enters the anti-condensation mode, and the second indoor unit demand is used to characterize the indoor unit demand when the multi-split air conditioner is running in the anti-condensation mode. Determine whether the demand for the second indoor unit is not greater than the demand for the first indoor unit; If so, the multi-split air conditioner will continue to operate in the anti-condensation mode.

5. The method according to claim 4, characterized in that, The method further includes: If the demand of the second indoor unit is greater than that of the first indoor unit, then the multi-split air conditioner is controlled to exit the anti-condensation mode.

6. The method of claim 1, wherein, The method further includes: If the multi-split air conditioner does not meet the preset anti-condensation conditions, the multi-split air conditioner will continue to operate in cooling mode.

7. A control device for preventing condensation in an indoor unit, applied to a multi-split air conditioner; characterized in that, The device for implementing the indoor unit anti-condensation control method according to any one of claims 1-6 includes: The acquisition module is used to acquire operating parameters when the multi-split air conditioner is in cooling mode; wherein, the operating parameters include: low pressure temperature, and the indoor relative humidity, dew point temperature, air outlet temperature and running time corresponding to the indoor unit, wherein the running time is used to characterize the duration for which the indoor unit continuously runs at low fan speed; The judgment module is used to determine whether the multi-split air conditioner meets the preset anti-condensation conditions based on the operating parameters. The execution module is configured to, if so, control the multi-split air conditioner to enter the anti-condensation mode, and in the anti-condensation mode, control the multi-split air conditioner to perform specified actions to prevent condensation from occurring in the indoor unit; wherein the specified actions include at least one of the following: valve opening adjustment, compressor frequency reduction, indoor unit fan speed fluctuation operation, and liquid tank status control.

8. A multi-split air conditioner, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the indoor unit anti-condensation control method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, performs the steps of the indoor unit anti-condensation control method according to any one of claims 1-6.

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