Air conditioner drainage control method, air conditioner indoor unit and air conditioner unit

Abstract

The application provides an air conditioner drainage control method, an air conditioner indoor unit and an air conditioner unit. The air conditioner drainage control method comprises the following steps: obtaining an evaporator surface temperature Tz, an environment temperature Th near the evaporator and a humidity RHz near the evaporator; when Tz is less than or equal to a preset temperature threshold T1 and RHz is greater than a preset humidity threshold RH1, calculating a condensate water accumulation amount Qa according to Tz, Th and RHz by using a preset condensate water prediction model, and recording a time length tc during which Tz is less than or equal to T1; if Qa is greater than a preset water amount threshold Q1 and tc is greater than or equal to a preset waiting time length td, starting a drainage pump to operate in a first mode. The application combines temperature and humidity parameters to determine condensate water conditions, estimates the condensate water accumulation amount by using a preset condensate water prediction model, and simultaneously increases the low-temperature continuous time length for verification, thereby solving the problems of drainage starting lag and water tray overflow caused by simply relying on a liquid level sensor, and preventing the drainage pump from idling and dry burning in a dry environment.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to air conditioning drainage control methods, air conditioning indoor units, and air conditioning units. Background Technology

[0002] During air conditioning operation, condensation forms on the surface of the indoor unit's evaporator due to the low temperature. This condensation collects in a drip tray, and when the level reaches a certain height, a drain pump needs to be activated to discharge the water outdoors. Existing drainage control solutions mainly rely on mechanical float switches or photoelectric level sensors. However, existing level detection solutions have the following drawbacks:

[0003] 1. Response lag: Traditional liquid level sensors only activate after the water level reaches the trigger threshold. In high humidity environments or under high load conditions, condensation occurs extremely quickly, and the physical accumulation of liquid level often lags behind the water production process, causing the drip tray to overflow instantly, resulting in water seepage from the ceiling or mold growth on the walls.

[0004] 2. Low hardware dependence and reliability: Reliance on liquid level sensors increases additional hardware costs, and the sensors are susceptible to dust, oil stains, or cracks in the internal sealing devices during transportation, leading to false alarms or failures.

[0005] 3. Lack of predictive capability: The existing system cannot intervene in advance according to the working conditions and can only passively deal with the current situation of water accumulation.

[0006] 4. Limitations of relying solely on temperature: Some temperature control schemes rely only on the absolute value of the evaporator temperature, ignoring the decisive influence of the actual moisture content of the air (relative humidity) on the water production rate. This can easily lead to misjudgment in dry environments (drain pump running dry), or delayed startup in high humidity environments due to failure to consider drainage distance and time.

[0007] Therefore, how to provide a feasible intelligent drainage solution is an urgent problem that needs to be solved in the industry. Summary of the Invention

[0008] The purpose of this invention is to provide an air conditioning drainage control method, an air conditioning indoor unit, and an air conditioning unit to solve the problem that passive drainage relying on liquid level sensors in the prior art easily leads to water overflow in the drip tray.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] In a first aspect, the present invention provides an air conditioning drainage control method applied to an indoor unit of an air conditioner. The indoor unit includes: a housing having a return air inlet and an air outlet, an evaporator disposed within the housing near the air outlet, and a water collection tray located below the evaporator and equipped with a drain pump. The air conditioning drainage control method includes:

[0011] Obtain the evaporator surface temperature Tz, the ambient temperature Th near the evaporator, and the humidity RHz near the evaporator;

[0012] When Tz ≤ preset temperature threshold T1 and RHz > preset humidity threshold RH1, the cumulative amount of condensate Qa is calculated based on Tz, Th and RHz using the preset water production prediction model, and the duration tc when Tz is continuously less than or equal to T1 is recorded.

[0013] If Qa > preset water volume threshold Q1 and tc ≥ preset waiting time td, then start the drainage pump to operate in the first mode.

[0014] Furthermore, the air conditioning drainage control method also includes:

[0015] If the temperature difference ΔT between Tz and Th is greater than or equal to the preset temperature difference threshold T2, and RHz is greater than or equal to the preset humidity threshold RH2, then the drain pump will be started to operate in the second mode.

[0016] Among them, RH2 > RH1, the start priority of the second mode is higher than that of the first mode, and the speed of the drain pump in the second mode is higher than that in the first mode.

[0017] Furthermore, the air conditioning drainage control method also includes:

[0018] After the drain pump is started in the first or second mode, if the drain pump's running time tp > preset time threshold ts, Tz > T1, and the condensate accumulation Qa does not increase, then the drain pump is turned off.

[0019] Furthermore, the air conditioning drainage control method also includes:

[0020] When a shutdown command is received, the operating mode of the drainage pump is determined;

[0021] If the drainage pump is operating in the first mode, the control will continue to run the drainage pump for a preset delay time tg1 before stopping;

[0022] If the drainage pump is operating in the second mode, the control will continue to run for a preset delay time tg2 before stopping;

[0023] Where tg1 < tg2.

[0024] Furthermore, the housing is equipped with indicator lights to indicate the drainage status, and the operating mode of the drainage pump is determined by:

[0025] If the indicator light flashes at the first flashing frequency, it indicates that the drain pump is operating in the first mode;

[0026] If the indicator light flashes at the second flashing frequency, it indicates that the drain pump is operating in the second mode;

[0027] The first flashing frequency is less than the second flashing frequency.

[0028] Furthermore, the cumulative condensate volume Qa is calculated based on Tz, Th, and RHz using a pre-defined permeate prediction model, including:

[0029] Calculate the cumulative condensate volume Qa using the following formula;

[0030] Qa(t)=Qa(t−1)+[ΔTeff×(RHz−RH1)×K1×Δt], ΔTeff=max(0, ΔT−T3);

[0031] Where Qa(t) is the current condensate accumulation, Qa(t−1) is the previous condensate accumulation, ΔTeff is the effective product water temperature difference, RHz is the humidity near the evaporator, RH1 is the preset humidity threshold, K1 is the preset correction coefficient, Δt is the sampling period, ΔT is the temperature difference between Tz and Th, and T3 is the preset temperature difference threshold.

[0032] Furthermore, an ambient humidity sensor is installed on the air inlet side of the evaporator to obtain the humidity RHz near the evaporator, including:

[0033] Receive the raw humidity value RHy measured by the ambient humidity sensor;

[0034] Multiply RHy by K2 to obtain the true relative humidity, which is RHz.

[0035] Wherein, K2 is the preset position compensation coefficient, which is a constant determined based on the installation position of the ambient humidity sensor relative to the evaporator.

[0036] Furthermore, the drip tray is equipped with a water guiding inclined layer to guide the condensate to the drain pump; the bottom of the evaporator is equipped with a water guiding inclined plate to guide the condensate to drip onto the water guiding inclined layer; the preset waiting time td is the time required for the condensate formed on the evaporator surface to drip onto the water guiding inclined layer and then flow to the drain pump.

[0037] Secondly, the present invention provides an air conditioner indoor unit, including a housing with a return air vent and an air outlet, an evaporator disposed inside the housing near the air outlet, and a water collection tray located below the evaporator and equipped with a drain pump. The controller of the air conditioner indoor unit executes the above-described air conditioner drainage control method.

[0038] Furthermore, the bottom of the evaporator is provided with a water-guiding inclined plate, the inside of the water receiving tray is provided with a fixed water flow layer for fixing the evaporator, and a water-guiding inclined layer located below the fixed water flow layer. The fixed water flow layer has inclined holes for the water-guiding inclined plate to be inserted, and the drain pump is installed at the lowest end of the water-guiding inclined layer.

[0039] Thirdly, the present invention provides an air conditioning unit, including the above-mentioned indoor air conditioning unit.

[0040] Compared with existing technologies, this invention combines temperature and humidity parameters to determine water production conditions, estimates the amount of condensate accumulation through a preset water production prediction model, and adds verification of the duration of low temperature. This solves the problems of delayed drainage start-up and overflow of the drip tray caused by relying solely on the liquid level sensor, and avoids malfunctions caused by relying only on the evaporator temperature and ignoring the actual moisture content. It also prevents the drainage pump from running dry in dry environments. Furthermore, through multiple determinations of temperature and humidity parameters, condensate accumulation, and duration of low temperature, the drainage pump is only started after it is confirmed that condensate is generated and has fully collected at the drainage pump position, achieving intelligent and proactive drainage control, effectively improving the timeliness, accuracy, and reliability of drainage. Attached Figure Description

[0041] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0042] Figure 1 This is a flowchart illustrating the air conditioning drainage control method of the present invention. Figure 1 ;

[0043] Figure 2 This is a flowchart illustrating the air conditioning drainage control method of the present invention. Figure 2 ;

[0044] Figure 3 This is a flowchart illustrating the air conditioning drainage control method of the present invention. Figure 3 ;

[0045] Figure 4 This is a flowchart illustrating the air conditioning drainage control method of the present invention. Figure 4 ;

[0046] Figure 5 This is a flowchart illustrating the air conditioning drainage control method of the present invention. Figure 5 ;

[0047] Figure 6 This is a flowchart illustrating the air conditioning drainage control method of the present invention. Figure 6 ;

[0048] Figure 7 This is a schematic diagram of the structure of the indoor unit of the air conditioner of this invention;

[0049] Figure 8 This is a simplified schematic diagram of the evaporator and drip tray in the indoor unit of the air conditioner of the present invention;

[0050] Figure 9 This is a schematic diagram of the evaporator structure in the indoor unit of the air conditioner of this invention;

[0051] Figure 10 This is a schematic diagram of the water collection tray in the indoor unit of the air conditioner of the present invention;

[0052] Figure 11 This is a cross-sectional schematic diagram of the evaporator and water tray in the indoor unit of the air conditioner of the present invention;

[0053] Figure 12 This is the present invention. Figure 11 Enlarged structural diagram at point A in the middle;

[0054] Explanation of reference numerals in the attached figures:

[0055] 1. Shell;

[0056] 21. Return air vent;

[0057] 22. Air vent;

[0058] 3. Evaporator;

[0059] 31. Inclined water-diverting plate;

[0060] 4. Water collection tray;

[0061] 41. Fixed water flow layer;

[0062] 42. Water-conducting inclined layer;

[0063] 43. Inclined hole;

[0064] 42. Drainage pump;

[0065] 5. Fan. Detailed Implementation

[0066] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0067] During air conditioning operation, condensation forms on the surface of the indoor unit's evaporator due to low temperatures. This condensation eventually collects in a drip tray below the evaporator. When the liquid level in the drip tray reaches a certain height, a drain pump needs to be activated to remove the condensation. Existing drainage control schemes mainly rely on mechanical float switches or photoelectric level sensors, but these liquid level detection schemes have the following drawbacks:

[0068] First, there is a lag in response: traditional liquid level sensors will only activate after the water accumulation reaches the trigger threshold. In high humidity environments or under high load conditions, condensation occurs very quickly, and the physical accumulation process of the liquid level often lags behind the water production process, which can easily cause the drip tray to overflow instantly, resulting in water seepage from the indoor ceiling or mold growth on the walls.

[0069] Second, it relies on hardware and has low reliability: relying on liquid level sensors increases the additional hardware cost, and the sensors are easily affected by dust and oil, or may malfunction due to cracks in the internal structural sealing device during transportation, ultimately leading to false alarms or functional failure.

[0070] Third, there is a lack of predictive capability: the existing system cannot intervene in drainage in advance according to the working conditions, and can only passively deal with the current situation of water accumulation.

[0071] Fourth, the single temperature judgment has limitations: some temperature control schemes only rely on the absolute value of the evaporator temperature for judgment, ignoring the decisive influence of the actual moisture content of the air (relative humidity) on the water production rate. This can easily lead to misjudgment in dry environments, causing the drain pump to run dry, or in high humidity environments, the drain pump starts too late and drainage is not timely because no drainage time has been reserved or the drainage distance has been considered.

[0072] Therefore, this invention proposes an intelligent drainage scheme that utilizes temperature and humidity sensor data from the unit, combined with temperature difference and time delay, to make comprehensive predictions. This aims to solve three problems in the existing technology: First, the problem of delayed drainage start-up due to reliance on level sensors, and the easy overflow of the drip tray under high humidity conditions; second, the problem of malfunctions caused by ignoring the actual humidity content of the air and relying solely on temperature difference estimation, such as the problem of the drainage pump running dry in a dry environment; and third, the problem of precise drainage control during the rapid flow of condensate to the drain outlet.

[0073] See Figure 1 , Figure 7 and Figure 8 This invention provides an air conditioning drainage control method applied to an indoor air conditioning unit. The indoor air conditioning unit includes: a housing 1 with a return air inlet 21 and an air outlet 22; an evaporator 3 disposed within the housing 1 near the air outlet 22; and a water collection tray 4 located below the evaporator 3 and equipped with a drain pump 42. The air conditioning drainage control method includes:

[0074] Obtain the evaporator surface temperature Tz, the ambient temperature Th near the evaporator, and the humidity RHz near the evaporator;

[0075] When Tz ≤ preset temperature threshold T1 and RHz > preset humidity threshold RH1, the cumulative amount of condensate Qa is calculated based on Tz, Th and RHz using the preset water production prediction model, and the duration tc when Tz is continuously less than or equal to T1 is recorded.

[0076] If Qa > preset water volume threshold Q1 and tc ≥ preset waiting time td, then start the drainage pump to operate in the first mode.

[0077] In practical applications, both the preset temperature threshold T1 and the preset humidity threshold RH1 can be flexibly set according to actual needs. In the preferred scheme, T1 is set to 5℃ and RH1 to 40%. If Tz≤5℃ and RHz>40%, it indicates that the basic condensation water production conditions are met.

[0078] The preset water production prediction model is used to estimate the cumulative water volume in the water receiving pan in real time. The preset water volume threshold Q1 is the preset water volume threshold for starting the drain pump. The preset waiting time td is used to confirm whether the condensate has flowed to the drain pump.

[0079] This invention combines temperature and humidity parameters to determine water production conditions, estimates the cumulative amount of condensate through a preset water production prediction model, and adds verification of the duration of low temperature. This solves the problems of delayed drainage start-up and overflow of the drip tray caused by relying solely on the liquid level sensor, and avoids malfunctions caused by relying only on the evaporator temperature and ignoring the actual moisture content. It also prevents the drainage pump from running dry in dry environments. Furthermore, through multiple determinations of temperature and humidity parameters, cumulative condensate, and duration of low temperature, the drainage pump is only started after it is confirmed that condensate is generated and has fully collected at the drainage pump position, realizing intelligent active drainage control and effectively improving the timeliness, accuracy, and reliability of drainage.

[0080] See Figure 2 Air conditioning drainage control methods also include:

[0081] If the temperature difference ΔT between Tz and Th is greater than or equal to the preset temperature difference threshold T2, and RHz is greater than or equal to the preset humidity threshold RH2, then the drain pump will be started to operate in the second mode.

[0082] Among them, RH2 > RH1, the start priority of the second mode is higher than that of the first mode, and the speed of the drain pump in the second mode is higher than that in the first mode.

[0083] In practical applications, both the preset temperature difference threshold T2 and the preset humidity threshold RH2 can be flexibly set according to actual needs. In the preferred scheme, T2 is set to 15℃ and RH2 to 75%. If ΔT≥15℃ and RH2>75%, it indicates that the extreme high humidity conditions are met.

[0084] This invention sets the second mode as a high-priority mode. When the temperature and humidity parameters meet the conditions of extreme high humidity, it can directly skip the multiple checks on the amount of condensate accumulation and the duration of low temperature, and immediately output a high-speed drainage command to drive the drainage pump to run continuously at high speed (for example, by adjusting the PWM duty cycle to the maximum). Under high humidity conditions, the rate of condensate generation is extremely fast. By "producing and draining simultaneously," overflow can be more effectively avoided, and the problem of instantaneous overflow of the drip tray under high humidity conditions can be better solved.

[0085] See Figure 3 Air conditioning drainage control methods also include:

[0086] After the drain pump is started in the first or second mode, if the drain pump's running time tp > preset time threshold ts, Tz > T1, and the condensate accumulation Qa does not increase, then the drain pump is turned off.

[0087] In practical applications, both the preset duration threshold ts and the preset temperature threshold T1 can be flexibly set according to actual needs. In the preferred scheme, ts is set to 60 seconds and T1 to 5℃. If tp > 60 seconds, Tz > 5℃ and ΔQa = 0, then the dry-burning risk conditions are met.

[0088] This invention combines multiple factors, including the running time of the drain pump, the temperature of the evaporator, and the amount of condensate accumulated, to make a multiple judgment. Once a risk of dry burning is confirmed, the drain pump is forcibly stopped, thus achieving dry burning fuse protection. This solves the problem of drain pump burning out due to long-term idling caused by sensor lag or structural blockage in traditional solutions.

[0089] See Figure 4 Air conditioning drainage control methods also include:

[0090] When a shutdown command is received, the operating mode of the drainage pump is determined;

[0091] If the drainage pump is operating in the first mode, the control will continue to run the drainage pump for a preset delay time tg1 before stopping;

[0092] If the drainage pump is operating in the second mode, the control will continue to run for a preset delay time tg2 before stopping;

[0093] Where tg1 < tg2.

[0094] In practical applications, the preset delay durations tg1 and tg2 can be flexibly set according to actual needs. In the preferred scheme, tg1 is set to 30 seconds and tg2 to 96 seconds. If the drainage pump is operating in the first mode before shutdown, extending the pump's operation by 30 seconds will be sufficient to discharge the residual water after normal operation; if the drainage pump is operating in the second mode before shutdown, extending its operation by 96 seconds will ensure the complete drainage of the large amount of residual water accumulated due to the rainstorm.

[0095] This invention sets different shutdown delay drainage times for different operating modes of the drainage pump, which can specifically drain the residual condensate in the water receiving pan, solving the technical problem of incomplete drainage of residual water at the moment of shutdown, and achieving the technical effects of extending equipment life and keeping the air outlet dry.

[0096] See Figure 5 The housing is equipped with indicator lights to indicate the drainage status. The operating mode of the drainage pump is determined by:

[0097] If the indicator light flashes at the first flashing frequency, it indicates that the drain pump is operating in the first mode;

[0098] If the indicator light flashes at the second flashing frequency, it indicates that the drain pump is operating in the second mode;

[0099] The first flashing frequency is less than the second flashing frequency.

[0100] In practical applications, both the first and second flashing frequencies can be flexibly set according to requirements. In the preferred embodiment, the first flashing frequency is set to flash once every 3 seconds, and the second flashing frequency is set to flash once every 1 second. When the drain pump is started and running in the first mode, light feedback is provided simultaneously, with the indicator light flashing once every 3 seconds; when the drain pump is started and running in the second mode, light feedback is provided simultaneously, with the indicator light flashing once every 1 second.

[0101] This invention distinguishes the current operating mode of a drainage pump by different flashing frequencies of indicator lights. After receiving a shutdown command, the operating mode of the drainage pump can be determined simply by reading the flashing state of the indicator lights before shutdown. The solution is simple and easy to implement.

[0102] In addition, the cumulative condensate volume Qa is calculated based on Tz, Th, and RHz using a pre-set permeate prediction model, including:

[0103] Calculate the cumulative condensate volume Qa using the following formula;

[0104] Qa(t)=Qa(t−1)+[ΔTeff×(RHz−RH1)×K1×Δt], ΔTeff=max(0, ΔT−T3);

[0105] Where Qa(t) is the current condensate accumulation, Qa(t−1) is the previous condensate accumulation, ΔTeff is the effective product water temperature difference, RHz is the humidity near the evaporator, RH1 is the preset humidity threshold, K1 is the preset correction coefficient, Δt is the sampling period, ΔT is the temperature difference between Tz and Th, and T3 is the preset temperature difference threshold.

[0106] In practical applications, ΔTeff is the effective water temperature difference after the temperature exceeds 10℃, where T3 is 10℃. The preset humidity threshold RH1, preset correction coefficient K1, and sampling period Δt can all be flexibly set according to actual needs. In the preferred scheme, RH1 is set to 40%, K1 to 1.15, and Δt to 1 second.

[0107] At this point, Qa(t) = Qa(t−1) + [ΔTeff×(RHz−40%)×1.15×1]. This formula is essentially based on the physical laws of air condensation. By using the integral concept, the continuous water production process is discretized into multiple time segments and accumulated to achieve real-time dynamic estimation of the accumulated condensate. The water production per unit time is proportional to the effective temperature difference and humidity difference. The water production per unit time is calculated once per second and accumulated to obtain the total water volume in the drip tray.

[0108] The above formula employs a dynamic calculation method of integral accumulation, which can track the condensate generation process in real time and obtain accurate current accumulated water volume at any time. This provides precise data support for the subsequent start-stop control of the drain pump, avoiding frequent start-stop of the drain pump or overflow of the drip tray due to inaccurate water volume detection, effectively improving the reliability of air conditioner drainage and user experience. Compared with solutions that rely on liquid level sensors to detect water volume, this invention eliminates the need for additional liquid level sensors, reducing the hardware cost of the air conditioner and avoiding detection errors caused by liquid level sensor failure, thus improving the stability and reliability of water volume estimation.

[0109] In addition, an ambient humidity sensor is installed on the air inlet side of the evaporator to obtain the humidity RHz near the evaporator, including:

[0110] Receive the raw humidity value RHy measured by the ambient humidity sensor;

[0111] Multiply RHy by K2 to obtain the true relative humidity, which is RHz.

[0112] Wherein, K2 is the preset position compensation coefficient, which is a constant determined based on the installation position of the ambient humidity sensor relative to the evaporator.

[0113] In the preferred embodiment, the ambient humidity sensor is installed in the air intake static pressure zone, and its probe center point is rigidly fixed in the airflow area 5cm to 8cm away from the evaporator fin surface, facing the return airflow direction.

[0114] Choosing 5cm-8cm as the fixed installation spacing is to accurately capture the true state of the mainstream air before it enters the boundary layer. The specific advantages are as follows:

[0115] ① Most representative: This region is located upstream of the effective heat exchange core area on the windward side of the evaporator. The airflow has not yet been significantly disturbed by the microscopic condensation film on the fin surface. The measured RHy best represents the original atmospheric moisture content entering the system.

[0116] ②Fastest dynamic response: Facing the return airflow direction and maintaining a suitable distance, the sensor can detect changes in airflow parameters within milliseconds when the ambient humidity suddenly increases (such as when opening a door on a rainy day or turning on a humidifier), providing the algorithm with the latest input signal.

[0117] ③ The constancy and effectiveness of support K2: Since the probe is always fixed at the calibrated position of 5cm-8cm, the heat and moisture transfer path between the sensor and the evaporator is relatively fixed. This allows the present invention to apply a constant preset position compensation coefficient K2 (value 0.95) to all operating conditions.

[0118] Since the location of the ambient humidity sensor is fixed, K2 is a constant value. After humidity compensation, RHz can accurately reflect the humidity content of the mainstream air, avoiding the false high humidity caused by condensate evaporation when the sensor is attached to the evaporator.

[0119] In addition, see Figures 7 to 12 The water receiving tray 4 is provided with a water guiding inclined layer 42 to guide the condensate to the drain pump 42; the bottom of the evaporator 3 is provided with a water guiding inclined plate 31 to guide the condensate to drip onto the water guiding inclined layer 42; the preset waiting time td is the time required for the condensate formed on the surface of the evaporator 3 to drip onto the water guiding inclined layer 42 via the water guiding inclined plate 31, and then flow to the drain pump 42 via the water guiding inclined layer 42.

[0120] By setting up a water-guiding inclined layer and a water-introducing inclined plate, the condensate produced by the evaporator can be smoothly collected at the drain pump, avoiding local stagnation of condensate in the water receiving pan; at the same time, the preset waiting time td conforms to the water flow pattern of the actual drainage path, which can ensure that there is enough condensate flowing in when the drain pump starts, which not only avoids the drain pump burning dry, but also allows the condensate to enter the drain pump quickly, achieving precise drainage control.

[0121] See Figures 7 to 12 The air conditioner indoor unit provided by the present invention includes a housing 1 with a return air inlet 21 and an air outlet 22, an evaporator 3 disposed in the housing 1 near the air outlet 22, and a water receiving tray 4 located below the evaporator 3 and equipped with a drain pump 42. The controller of the air conditioner indoor unit executes the above-mentioned air conditioner drainage control method.

[0122] Because the aforementioned air conditioning drainage control method combines temperature and humidity parameters to determine water production conditions and estimates the accumulated condensate using a preset water production prediction model, while also adding verification based on the duration of low temperature, it solves the problems of delayed drainage start-up and overflowing of the drip tray caused by relying solely on a liquid level sensor. It also avoids malfunctions caused by relying solely on evaporator temperature and ignoring actual moisture content, preventing the drain pump from running dry in dry environments. Furthermore, through multiple determinations based on temperature and humidity parameters, accumulated condensate, and duration of low temperature, the drain pump is only activated after confirming condensate production and sufficient accumulation at its location, achieving intelligent and proactive drainage control. This effectively improves the timeliness, accuracy, and reliability of drainage. Therefore, after applying this drainage control method to the indoor unit of the air conditioner, the problems of drip tray overflow and drain pump dry running can be effectively avoided, significantly improving operational reliability and service life.

[0123] See Figures 7 to 12 The bottom of the evaporator 3 is provided with a water-guiding inclined plate 31. The inside of the water receiving tray 4 is provided with a fixed water flow layer 41 for fixing the evaporator 3, and a water guiding inclined layer 42 located below the fixed water flow layer 41. The fixed water flow layer 41 has an inclined hole 43 for the water-guiding inclined plate 31 to be inserted. The drain pump 42 is installed at the lowest end of the water guiding inclined layer 42.

[0124] The inclined water guide plate can guide the condensate generated on the surface of the evaporator to drip smoothly through the inclined holes of the fixed water flow layer and collect into the inclined water guide layer. Then, it flows along the slope of the inclined water guide layer to the drain pump located at the lowest end, avoiding the accumulation of condensate inside the water receiving pan, further reducing the risk of water overflow from the water receiving pan, and ensuring that the drain pump can stably draw the collected condensate, thus improving drainage efficiency.

[0125] In the preferred embodiment, the angle α between the inclined water-guiding plate and the horizontal line is 60°~75°, and the angle β between the inclined water-guiding layer and the horizontal line is 3°~4°.

[0126] The angle α between the water-guiding inclined plate and the horizontal line is limited to 60°~75°. This is because in traditional structures, the fins are arranged vertically or randomly, resulting in dispersed condensate dripping times. This makes it difficult for the algorithm to predict the time it takes for the condensate to reach the drainage pump, and thus, it is impossible to determine the preset waiting time td. This invention limits the angle α to 60°~75°. Experiments have shown that at this angle, the standard deviation of the condensate dripping time from the fins is ≤8 seconds, while in traditional structures it is 13-16 seconds. This design significantly reduces the difficulty of the algorithm in compensating for "drip time fluctuations," reducing the calculation error of the preset waiting time td from ±20% to ±5%. The water-guiding inclined plate is inserted into the inclined hole of the fixed water layer, allowing the water collected by the inclined plate to be smoothly guided into the water-guiding inclined layer.

[0127] The angle β between the inclined water-guiding layer and the horizontal line is limited to 3°~4°. This is because in traditional flat-bottomed water receiving trays, the water flow velocity is greatly affected by the water volume; a small water volume results in a slow flow velocity, which can lead to deviations in td calculations. The present invention uses a guide drop (height h=3-5mm) combined with an angle β (3°~4°) to form an inclined flow channel, reducing the correlation between water flow velocity and water volume. This ensures that the flow velocity remains stable even at low water volumes, solving the technical problem of "unstable flow velocity at low water volumes leading to algorithm misjudgments."

[0128] Through experimentation, a multi-point staining method was used for measurement: three typical positions (left, middle, and right) were selected in the width direction of the evaporator, and different colored inks (such as red, blue, and yellow) were dripped on them respectively. The time taken for each color ink to travel from the water inlet tilt plate to the water guide tilt layer and then to the drainage pump was recorded. Finally, the average of the three times was taken as the preset waiting time td.

[0129] Compared to traditional flat-bottomed water trays, water trays with only a water-guiding inclined layer can reduce the preset waiting time td by 16 seconds; a scheme combining an evaporator with a water-guiding inclined plate and a water tray with a water-guiding inclined layer can save 24 seconds of the preset waiting time td compared to traditional flat-bottomed water trays.

[0130] The air conditioning unit provided by this invention includes the aforementioned indoor air conditioning unit. Because the indoor air conditioning unit employs intelligent active drainage control, the overall operational stability of the air conditioning unit is improved.

[0131] To facilitate understanding of the present invention, the following will provide an overall introduction to the scheme for intelligent drainage control that utilizes hardware structure and control logic in conjunction with preferred embodiments.

[0132] See Figures 7 to 12 The indoor unit of an air conditioner mainly includes a casing 1, a fan 5, an evaporator 3, and a drip tray 4.

[0133] The housing 1 is equipped with an indicator light, and a return air inlet 21 and an air outlet 22 are respectively opened on opposite sides. The fan 5 is installed inside the housing 1 near the return air inlet 21, and the evaporator 3 is installed inside the housing 1 near the air outlet 22. The water receiving tray 4 is located below the evaporator 3. The bottom of the evaporator 3 is provided with a water-guiding inclined plate 31. The inside of the water receiving tray 4 is provided with a fixed water flow layer 41 for fixing the evaporator 3, and a water-guiding inclined layer 42 located below the fixed water flow layer 41. The fixed water flow layer 41 has inclined holes 43 for the water-guiding inclined plate 31 to be inserted, and a drain pump 42 is installed at the lowest end of the water-guiding inclined layer 42.

[0134] The indoor unit of the air conditioner also includes an ambient temperature sensor, an ambient humidity sensor, and an evaporator 3 temperature sensor. The ambient temperature sensor and the ambient humidity sensor are mounted on the same bracket and arranged in the air inlet static pressure zone of the evaporator 3. The evaporator 3 temperature sensor is in close contact with the surface of the copper tube or fins of the evaporator 3.

[0135] Based on the above-mentioned structure of the air conditioner indoor unit, the following section first introduces the relevant formulas and parameter definitions.

[0136] ΔTeff = max(0, ΔT−T3);

[0137] ΔQ=[ΔTeff×(RHz−RH1)×K1×Δt];

[0138] Qa(t) = Qa(t−1) + ΔQ;

[0139] Where Qa(t) is the current condensate accumulation, Qa(t−1) is the previous condensate accumulation, ΔTeff is the effective product water temperature difference, RHz is the humidity near the evaporator, RH1 is the preset humidity threshold, K1 is the preset correction coefficient, Δt is the sampling period, ΔT is the temperature difference between Tz and Th, and T3 is the preset temperature difference threshold.

[0140] In the preferred scheme, T3 is set to 10℃, and ΔTeff is the effective product water temperature difference when the temperature difference exceeds 10℃. Only when ΔT>10℃ is an effective product water driving force determined. RH1 is set to 40%, K1 is set to 1.15, and Δt is set to 1 second. K1 is determined based on the flow guiding structure of the evaporator and the water receiving tray, corresponding to the structural design of "the evaporator is equipped with a water-guiding inclined plate, and the water receiving tray is equipped with a water-guiding inclined layer".

[0141] RHz = RHy * K2. Where RHy is the raw humidity value directly measured by the ambient humidity sensor, and RHz is the true relative humidity obtained after structural compensation, reflecting the actual humidity of the air environment. K2 is set to 0.95, a constant obtained through actual measurement and calibration based on a fixed layout where the ambient humidity sensor is 5-8 cm away from the evaporator.

[0142] td = ta * K3. Where ta is the time it takes for condensate to drip and collect at the drain pump before the improvement, which is the time required for water in the flat-bottomed drip tray to drip and collect at the drain pump. K3 is the preset flow coefficient, a constant calibrated for this specific rapid water intake structure of "evaporator with inclined water guide vanes and drip tray with inclined water guide layer". td is the time it takes for condensate to drip and collect at the drain pump after the improvement, which is the actual waiting time required for water droplets to drip and flow to the drain pump outlet based on the flow guide structure settings of the evaporator and drip tray.

[0143] For example, the theoretical time ta of a traditional flat-bottomed water receiving tray is about 120 seconds (2 minutes). After the flow guiding structure of this invention is optimized and accelerated, td is corrected to 120 × 0.8 = 96 seconds (1.6 minutes). At this time, K3 is taken as 0.8.

[0144] tc represents the duration for which the evaporator surface remains at a low temperature (≤5℃), and is used for comparison with td. Only when tc ≥ td is it determined that condensate has flowed to the drain pump, at which point the drain pump can be turned on.

[0145] tp represents the running time of the drainage pump, used to record the operating time of the drainage pump.

[0146] Tz is the surface temperature of the evaporator measured by the evaporator temperature sensor.

[0147] Th represents the ambient temperature near the evaporator as measured by the ambient temperature sensor.

[0148] Qa represents the cumulative condensate volume, used to record the total cumulative effective product water temperature difference.

[0149] tg1 and tg2 are both preset delay durations used to indicate the continued running time of the drain pump when the air conditioner is about to be turned off.

[0150] See Figure 6 The following is a detailed explanation of the air conditioning drainage control method:

[0151] Obtain the evaporator surface temperature Tz, the ambient temperature Th near the evaporator, and the humidity RHz near the evaporator;

[0152] First, determine whether the basic conditions for condensation are met.

[0153] Judgment conditions: (Tz≤5℃)AND(RHz>40%).

[0154] If the conditions are not met (e.g., temperature rises or air is too dry): it is judged as "invalid water production", the drain pump is forcibly stopped, Qa and tc are reset, and the indicator light stays on as an alarm (or goes out).

[0155] If satisfied: Proceed to the next step.

[0156] Next, determine whether the operating conditions are extremely high humidity.

[0157] Judgment conditions: (ΔT≥15℃) AND (RHz≥75%).

[0158] If the conditions are met, the drain pump will be started immediately in the second mode. At this time, the drain pump will be driven to run continuously at high speed (PWM duty cycle is adjusted to the maximum). The control indicator light will flash once every 1 second to remind the user that the current situation is an emergency drainage state.

[0159] If the conditions are not met, the normal control logic will be invoked, requiring all three checks to be met simultaneously:

[0160] Time check: Does it satisfy tc≥td (i.e. ≥96s)?

[0161] Water quantity verification: Does it satisfy Qa > Q1?

[0162] Humidity check: Does it meet the requirement of RHz > 40%?

[0163] If all conditions are met, the drain pump will be started immediately and the system will enter the first mode. At this time, the drain pump will run at low speed, and the control indicator light will flash once every 3 seconds to indicate to the user that the system is currently in normal drainage mode.

[0164] If any condition is not met (such as time not being reached or insufficient water volume), keep the drain pump stopped and continue updating Qa.

[0165] In addition, a dry-burning fuse protection strategy is also provided.

[0166] During the drainage process, the running time of the drainage pump and the temperature change of the evaporator are monitored in real time.

[0167] Judgment conditions: (Tp>60s) AND (Tz>5℃) AND (ΔQ=0).

[0168] If the above conditions are met, the drainage pump will be forcibly stopped, and the indicator light will be set to stay on (i.e., not flashing) as an alarm signal.

[0169] In addition, a shutdown and venting strategy is also in place.

[0170] Upon receiving a shutdown command, read the indicator light status before shutdown:

[0171] If the lights are flashing once per second, extend the operation of the drainage pump for 96 seconds to ensure that the large amount of residual water accumulated due to the rainstorm is completely drained.

[0172] If the light flashes once every 3 seconds, extend the operation of the drain pump for 30 seconds to remove the residual water after normal operation.

[0173] If the pump is off, stop the drainage pump immediately.

[0174] In summary, this invention proposes a third-order collaborative drainage strategy that integrates real-time humidity monitoring, temperature difference integration, and delay compensation mechanisms.

[0175] At the structural level, this invention eliminates data distortion by optimizing the sensor layout and reconstructs the flow guiding structure of the evaporator and the drip tray, thereby achieving accurate determination of condensate production and proactive overflow prevention management.

[0176] At the methodological level, this invention sets up a dual-modal intelligent switching and fuse protection logic: it designs a dynamic switching mechanism between "normal mode" (drainage pump operates at low speed) and "rainstorm mode" (drainage pump operates at high speed), and adds "dry-burning fuse protection" (forced shutdown of drainage pump operation). Traditional solutions relying on liquid level sensors require waiting for a fixed water accumulation time, which easily leads to overflow; in contrast, the "rainstorm mode" of this invention dynamically shortens the response delay by identifying combinations of high heat load and high humidity, ensuring that drainage capacity always matches the instantaneous peak water production. The "normal mode" of this invention, through time and water volume verification, ensures both no overflow and avoids dry-burning of the drainage pump. The "dry-burning fuse protection" of this invention solves the problem of drainage pump burnout due to long-term idling caused by sensor lag or structural blockage in traditional solutions, ensuring operational safety.

[0177] Therefore, this invention does not require the addition of a physical liquid level sensor. It only uses the temperature and humidity sensor data that is standard on the equipment to achieve water level estimation and control through the internal timer and calculation logic of the main control unit. It is a pure algorithm-based solution with zero hardware modification, realizing low-cost and high-reliability intelligent control.

[0178] It should be noted that the terminology used above is for describing specific embodiments only and is not intended to limit the exemplary embodiments of the present invention. When the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. The order of execution of actions, steps, etc., in the apparatus and methods shown in the specification and drawings may be implemented in any order unless a specific express order is specified, and as long as the output of a previous process is not used in a subsequent process. Similar sequential terms used for ease of description do not imply that such an order must be followed.

[0179] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as constraints. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0180] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An air conditioning drainage control method, applied to an indoor unit of an air conditioner, the indoor unit comprising: A housing having a return air inlet and an air outlet, an evaporator disposed within the housing near the air outlet, and a water collection tray located below the evaporator and equipped with a drain pump, characterized in that the air conditioning drainage control method includes: Obtain the evaporator surface temperature Tz, the ambient temperature Th near the evaporator, and the humidity RHz near the evaporator; When Tz ≤ preset temperature threshold T1 and RHz > preset humidity threshold RH1, the cumulative amount of condensate Qa is calculated based on Tz, Th and RHz using the preset water production prediction model, and the duration tc when Tz is continuously less than or equal to T1 is recorded. If Qa > preset water volume threshold Q1 and tc ≥ preset waiting time td, then the drainage pump is started to operate in the first mode.

2. The air conditioning drainage control method as described in claim 1, characterized in that, The air conditioning drainage control method further includes: If the temperature difference ΔT between Tz and Th is greater than or equal to the preset temperature difference threshold T2, and RHz is greater than or equal to the preset humidity threshold RH2, then the drainage pump is started to operate in the second mode. Among them, RH2 > RH1, the start priority of the second mode is higher than that of the first mode, and the speed of the drainage pump in the second mode is higher than that in the first mode.

3. The air conditioning drainage control method as described in claim 2, characterized in that, The air conditioning drainage control method further includes: After the drain pump is started in the first mode or the second mode, if the running time tp of the drain pump is greater than the preset time threshold ts, Tz is greater than T1 and the condensate accumulation Qa does not increase, then the drain pump is turned off.

4. The air conditioning drainage control method as described in claim 2, characterized in that, The air conditioning drainage control method further includes: When a shutdown command is received, the operating mode of the drainage pump is determined; If the drainage pump is operating in the first mode, the drainage pump is controlled to continue operating for a preset delay time tg1 and then stop. If the drainage pump is operating in the second mode, the drainage pump is controlled to continue operating for a preset delay time tg2 before stopping; Where tg1 < tg2.

5. The air conditioning drainage control method as described in claim 4, characterized in that, The housing is equipped with an indicator light for indicating the drainage status. The operating mode of the drainage pump is determined by: If the indicator light flashes at the first flashing frequency, it is determined that the drainage pump is operating in the first mode; If the indicator light flashes at the second flashing frequency, it is determined that the drain pump is operating in the second mode; Wherein, the first flashing frequency is less than the second flashing frequency.

6. The air conditioning drainage control method as described in claim 1, characterized in that, The cumulative condensate volume Qa is calculated based on Tz, Th, and RHz using a pre-defined product water prediction model, including: Calculate the cumulative condensate volume Qa using the following formula; Qa(t)=Qa(t−1)+[ΔTeff×(RHz−RH1)×K1×Δt], ΔTeff=max(0, ΔT−T3); Where Qa(t) is the current condensate accumulation, Qa(t−1) is the previous condensate accumulation, ΔTeff is the effective product water temperature difference, RHz is the humidity near the evaporator, RH1 is the preset humidity threshold, K1 is the preset correction coefficient, Δt is the sampling period, ΔT is the temperature difference between Tz and Th, and T3 is the preset temperature difference threshold.

7. The air conditioning drainage control method as described in claim 1, characterized in that, An ambient humidity sensor is installed on the air inlet side of the evaporator to obtain the humidity RHz near the evaporator, including: Receive the raw humidity value RHy measured by the ambient humidity sensor; Multiply RHy by K2 to obtain the true relative humidity, which is RHz. Wherein, K2 is a preset position compensation coefficient, which is a constant determined based on the installation position of the ambient humidity sensor relative to the evaporator.

8. The air conditioning drainage control method as described in claim 1, characterized in that, The water receiving tray has a water guiding inclined layer inside, which is used to guide the condensate to flow to the drain pump; the bottom of the evaporator has a water guiding inclined plate, which is used to guide the condensate to drip onto the water guiding inclined layer; the preset waiting time td is the time required for the condensate formed on the evaporator surface to drip onto the water guiding inclined layer through the water guiding inclined plate and then flow to the drain pump through the water guiding inclined layer.

9. An indoor unit for an air conditioner, comprising a housing having a return air vent and an air outlet, an evaporator disposed within the housing near the air outlet, and a drip tray located below the evaporator and equipped with a drain pump, characterized in that, The controller of the indoor unit of the air conditioner executes the air conditioner drainage control method as described in any one of claims 1 to 8.

10. The air conditioner indoor unit as described in claim 9, characterized in that, The evaporator is provided with a water-guiding inclined plate at the bottom. The water receiving tray is provided with a fixed water flow layer for fixing the evaporator and a water-guiding inclined layer located below the fixed water flow layer. The fixed water flow layer has an inclined hole for the water-guiding inclined plate to be inserted. The drain pump is installed at the lowest end of the water-guiding inclined layer.

11. An air conditioning unit, characterized in that, Including the air conditioning indoor unit as described in claim 9 or 10.

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