Cleaning method of range hood

Abstract

The invention discloses a cleaning method of a range hood, which comprises the following steps: entering a cleaning mode, starting a water pump module and acquiring the water inlet temperature; the water pump module is closed, the heating module is started, and the heating time needed for heating water from the water inlet temperature to the target temperature is obtained; calculating a preset duty ratio of a water pump module according to the water inlet temperature and the heating time; and controlling the water pump module to work according to the preset duty ratio. The problems that an extractor hood is low in cleaning energy efficiency, unstable in cleaning effect and the like are solved.

Description

Technical Field

[0001] This application relates to the field of range hood technology, and in particular to a method for cleaning range hoods. Background Technology

[0002] Traditional high-temperature steam cleaning technology generally suffers from inherent drawbacks such as crude control, low energy efficiency, and unstable cleaning results. Most range hoods use a simple open-loop control mode of "heating + timed water intake," which cannot cope with complex operating conditions such as changes in ambient temperature, fluctuations in inlet water temperature, unstable voltage, and reduced heater efficiency. This leads to inconsistent cleaning results, either insufficient water leading to the danger of dry burning and energy waste, or excessive water resulting in insufficient steam vaporization rate, insufficient oil dissolving temperature, and ineffective cleaning, while consuming a large amount of water throughout the process. Summary of the Invention

[0003] This application aims to at least partially address the problems of low cleaning efficiency and unstable cleaning results in range hoods. To this end, the first aspect of this application provides a method for cleaning range hoods.

[0004] The cleaning method for a range hood provided above is achieved through the following technical solution:

[0005] A method for cleaning a range hood, the range hood comprising a main body, a data acquisition module, a heating module, a water pump module, and a fan module, the cleaning method comprising the following steps:

[0006] Enter cleaning mode, turn on the water pump module and obtain the inlet water temperature; turn off the water pump module and turn on the heating module, obtain the heating time required to heat the water from the inlet water temperature to the target temperature; calculate the preset duty cycle of the water pump module based on the inlet water temperature and the heating time; control the water pump module to work according to the preset duty cycle.

[0007] In some embodiments, the specific steps of controlling the water pump module to operate according to the preset duty cycle include: acquiring the temperature change trend of the water temperature; adjusting the preset duty cycle according to the temperature change trend; and controlling the water pump module to operate according to the adjusted preset duty cycle.

[0008] In some embodiments, the specific steps of adjusting the preset duty cycle according to the temperature change trend and controlling the water pump module to operate according to the adjusted preset duty cycle include: if the temperature change trend is zero, then the preset duty cycle is not adjusted, and the water pump module is controlled to operate according to the original preset duty cycle; if the temperature change trend increases, then the preset duty cycle is increased, and the water pump module is controlled to operate according to the increased preset duty cycle; if the temperature change trend decreases, then the preset duty cycle is decreased, and the water pump module is controlled to operate according to the decreased preset duty cycle.

[0009] In some embodiments, the specific steps for obtaining the temperature change trend of the water include: continuously obtaining the average water temperature for multiple calculation cycles, wherein the calculation cycle is the interval between two adjacent water sprays by the water pump module; determining the average heating rate based on the average water temperature for multiple calculation cycles; and determining whether the temperature change trend is zero, increasing, or decreasing based on the magnitude of the average heating rate.

[0010] In some embodiments, the specific steps of calculating the preset duty cycle of the water pump module based on the inlet water temperature and the heating time include: obtaining the actual heating power by looking up a table or calculation based on the heating time; and calculating the preset duty cycle of the water pump module based on the inlet water temperature and the actual heating power.

[0011] In some implementations, the preset duty cycle is calculated using the following formula: In the formula, η is the target steam vaporization rate, and P u Q represents the actual heating power of the heating module. max Q is the rated flow rate of the pump module at 100% duty cycle. in D is the total influent flow rate, C is the preset duty cycle, and D is the total influent flow rate. p T is the specific heat capacity of water at constant pressure. b and T in These represent the boiling point of water and the inlet water temperature, H. v It is the latent heat of vaporization of water.

[0012] In some embodiments, the specific steps for obtaining the heating time required to heat the water from the inlet temperature to the target temperature include: starting the heating timer while turning on the heating module; obtaining and determining whether the real-time water temperature is not lower than the target temperature; and when the real-time water temperature is not lower than the target temperature, obtaining the heating time required to raise the water temperature from the inlet temperature to the target temperature.

[0013] In some embodiments, the specific steps of turning on the water pump module and obtaining the inlet water temperature include: turning on the water pump module and starting to record the pumping time; determining whether the pumping time has reached the preset pumping time; and obtaining the inlet water temperature of the cleaning system when the pumping time reaches the preset pumping time.

[0014] In some embodiments, before turning on the water pump module and obtaining the inlet water temperature, the cleaning method further includes the following steps: obtaining the ambient temperature and inherent parameters of the range hood body; and calculating the theoretical energy threshold required to melt the oil stains inside the range hood body based on the ambient temperature and the inherent parameters.

[0015] In some embodiments, while or after the water pump module is controlled to operate according to the preset duty cycle, the cleaning method further includes the following steps: obtaining the temperature of the casing of the main body of the range hood; when the casing temperature is greater than the melting oil temperature and continues for a set time, turning off the heating module and the water pump module, and turning on the fan module.

[0016] Compared with the prior art, this application has at least the following beneficial effects:

[0017] This application provides a cleaning method for a range hood. By calculating the preset duty cycle of the water pump module based on the inlet water temperature and heating time, and controlling the working state of the water pump module accordingly, the preset water spray volume of the water pump module is intelligently adjusted. This transforms the steam generation process from a "black box" operation into a "white box" optimization process, ultimately achieving efficient, safe, water-saving, and adaptive intelligent cleaning. Attached Figure Description

[0018] Figure 1 The connection block diagram of the range hood in this embodiment is shown;

[0019] Figure 2 The flowchart of the cleaning method in this embodiment is shown. Figure 1 ;

[0020] Figure 3 The flowchart of the cleaning method in this embodiment is shown. Figure 2 .

[0021] In the diagram: 1-Main body of the range hood, 11-Outer shell assembly, 12-Box assembly; 2-Main control module; 3-Acquisition module, 31-Temperature sensor, 32-Timer; 4-Heating module, 41-Heating element, 42-Heating channel; 5-Water pump module; 6-Fan module. Detailed Implementation

[0022] The following embodiments illustrate this application, but this application is not limited to these embodiments. Modifications to the specific implementation of this application or equivalent substitutions for some technical features, without departing from the spirit of this application, should all be covered within the scope of the technical solution claimed in this application.

[0023] Example 1

[0024] refer to Figure 1This embodiment provides a cleaning method for a range hood. The range hood includes a main body 1, a main control module 2, and a cleaning system. The main body 1 includes a shell assembly 11 and a housing assembly 12 installed on top of the shell assembly. The main control module 2 is installed on the main body 1, preferably on top of the housing assembly 12. The cleaning system includes an acquisition module 3, a heating module 4, a water pump module 5, and a fan module 6 installed inside the housing assembly 12. The acquisition module includes a temperature sensor 31 and a timer 32. The temperature sensor 31 is disposed on the heating module 4 and electrically connected to the main control module 2, and is used to detect the ambient temperature and the inlet water temperature of the heating module 4. This allows for the measurement of temperature parameters affecting steam output, such as ambient temperature and inlet water temperature, using only one temperature sensor in conjunction with an intelligent algorithm, thereby reducing costs. The timer 32 is electrically connected to the main control module and is used to record the heating time of the heating module 4 and the pumping time of the water pump module 5. This allows the actual heating power, heat loss rate and other working parameters that affect steam output to be measured using only one temperature sensor and the timer 32.

[0025] The heating module 4 is preferably a steam generator mounted on the main body of the range hood. This steam generator includes a heating element 41 and a heating channel 42. The inlet of the heating channel 42 is connected to tap water or a cleaning water tank via a water pump module 5. The outlet of the heating channel 42 is connected to a nozzle assembly mounted on the fan module 6. The nozzle assembly sprays the cleaning medium into the fan module to clean it. A temperature sensor 31 is installed on the heating channel 42 to detect the ambient temperature and the inlet water temperature. The heating element 41 heats the water in the heating channel 42 to a target temperature higher than the boiling point of water, thus providing high-temperature steam to the fan module, enabling the range hood to have a steam cleaning function for efficient cleaning. The water pump module 5 may include only an inlet pump, or it may include both an inlet pump and a drain pump. The inlet pump can be configured to pump water into the heating channel of the heating module, and the drain pump can be configured to drain the water stored in the water tank assembly and / or the heating channel of the heating module. When the water pump module 5 includes only an inlet pump, the inlet pump can be controlled to rotate in both directions to have both inlet and drain functions. When the inlet pump rotates in the forward direction, it can deliver water into the heating channel; conversely, when the inlet pump rotates in the reverse direction, it can drain the water stored in the heating channel to prevent water accumulation in the heating channel from forming troughs and breeding bacteria.

[0026] refer to Figure 2-3 The cleaning method for range hoods includes the following steps:

[0027] S1, enter cleaning mode, turn on water pump module and obtain inlet water temperature;

[0028] Specifically, the range hood's cleaning mode includes a cleaning preparation stage and a steam oil-dissolving cleaning stage. When entering the cleaning mode, the cleaning preparation stage is entered first. In this stage, the water pump module 5 is turned on and the heating module 4 is turned off. At this time, only water is introduced, but no heating is performed to prevent the heating module from dry burning due to lack of water. The water pump module 5 delivers water to the heating channel of the heating module so that the water can flow through the temperature sensor 31. At this time, the temperature sensor 31 of the acquisition module detects the water temperature in the heating channel. The water temperature is at room temperature, and its magnitude is positively correlated with the ambient temperature.

[0029] In addition, before the water pump module 5 pumps water to the heating channel of the heating module, the water pump module 5 can first drain the water in the heating channel to prevent inaccurate water flow due to water accumulation. This can be done by using the drain pump of the water pump module 5 to drain the water, or by reversing the water inlet pump of the water pump module 5 until it runs dry. Furthermore, before turning on the water pump module, the initial temperature in the heating channel can be detected by the temperature sensor 31 of the module; this initial temperature is the ambient temperature. Therefore, by using a single temperature sensor 31 combined with an intelligent algorithm, temperature parameters affecting steam output, such as ambient temperature and inlet water temperature, can be measured.

[0030] S2, turn off the water pump module and turn on the heating module, and obtain the heating time required to heat the water from the inlet temperature to the target temperature;

[0031] Specifically, the target temperature is higher than the boiling point of water, preferably 110°C. By turning off the water pump module and turning on the heating module, the water in the heating module is heated rapidly. Simultaneously with turning on the heating element 42 of the heating module, the timer 32 of the acquisition module starts timing and records the heating time required to heat the water in the heating module from the inlet water temperature to the target temperature. Furthermore, based on the heating time, the actual heating power of the heating module can be obtained through a lookup table or calculation. During the heat loss assessment phase, based on this actual heating power and the theoretical heating power, the heat loss rate can be calculated, thereby automatically compensating for the effects of grid voltage fluctuations and heater performance changes.

[0032] S3, calculate the preset duty cycle of the water pump module using a formula based on the inlet water temperature and the heating time;

[0033] S4, control the water pump module to work according to the preset duty cycle.

[0034] Specifically, after calculating the preset duty cycle of the water pump module, the range hood enters the steam oil-dissolving cleaning stage, controlling the water pump module to operate according to the preset duty cycle calculated in step S3. Furthermore, to improve adaptability and compensate for the impact of grid voltage fluctuations and performance changes in the heating module and water pump module, the temperature change trend detected by the temperature filtering algorithm can be used during the steam oil-dissolving cleaning stage. The preset duty cycle is adjusted based on the temperature change trend, and the water pump module's on / off state is controlled according to the adjusted preset duty cycle.

[0035] In addition, when entering the steam oil-dissolving cleaning stage, the timer starts to record the specific cleaning time. When the specific cleaning time reaches the set cleaning time, the heating module and water pump module are turned off, and the cleaning ends; then it enters the oil-spinning stage, and after the fan module runs for a period of time, the remaining water in the cleaning system is drained. Alternatively, the main body of the range hood 1 and the fan module 6 can be heated and dried, and the entire cleaning mode ends.

[0036] Therefore, the cleaning method of this application calculates the preset duty cycle of the water pump module based on the inlet water temperature and heating time, and controls the working state of the water pump module accordingly. This enables intelligent adjustment of the preset water spray volume of the water pump module, transforming the steam generation process from a "black box" operation into a "white box" optimization process. Ultimately, this achieves efficient, safe, water-saving, and adaptive intelligent cleaning, solving the problems of crude control, low energy efficiency, and unstable cleaning effect in existing high-temperature steam cleaning technologies.

[0037] refer to Figure 3 Furthermore, in step S1, the specific steps of turning on the water pump module and obtaining the inlet water temperature include:

[0038] S11, turn on the water pump module and start recording the pumping time;

[0039] Specifically, the water pump module is turned on and the heating module is turned off. Turning on the water pump module delivers water to the heating module, which facilitates accurate detection of the inlet water temperature and prevents the heating module from running dry. At the same time as the water pump module is turned on, timer 32 starts timing the water pumping, that is, it begins recording the water pumping time.

[0040] S12, determine whether the pumping time has reached the preset pumping time;

[0041] Specifically, the preset pumping time is 3-10 seconds, and can be any of 3s, 4s, 5s, 6s, 7s, 8s, or 9s. The preset pumping time is positively correlated with the inlet water flow rate and negatively correlated with the steam output rate. Manufacturers or users can set it according to specific requirements. The main control module 2 obtains the pumping time in real time through timer 32 and determines whether the pumping time has reached the preset pumping time. If the pumping time has not reached the preset pumping time, this step S12 continues.

[0042] S13: When the pumping time reaches the preset pumping time, obtain the inlet water temperature of the cleaning system.

[0043] Specifically, when the pumping time reaches the preset pumping time, for example, ≥3 seconds, ensure that water flows through the temperature sensor and fills the heating channel. The temperature at this point is then read as the inlet water temperature. By detecting the inlet water temperature only after a certain period of time, the influence of unstable factors on temperature detection can be reduced, thus improving the accuracy of inlet water temperature detection. It should be noted that the inlet water temperature can be detected before the pump module is turned off, or before the pump module is turned off and the heating module is turned on.

[0044] refer to Figure 3 Furthermore, in step S2, the specific steps for obtaining the heating time required to heat the water to the target temperature include:

[0045] S21, Start heating timing at the same time as turning on the heating module;

[0046] Specifically, when the heating module is turned on, the timer 32 of the acquisition module starts heating timing and records the heating time required to heat the water in the heating module from the inlet water temperature to the target temperature. At the same time or after the heating module is turned on, the temperature sensor 31 of the acquisition module collects temperature data at 100ms intervals, or it can collect temperature data every 50ms, 150ms or 200ms.

[0047] S22, acquire and determine whether the real-time water temperature is not less than the target temperature;

[0048] Specifically, the target temperature is 105-120℃, preferably 110℃. Temperature sensor 31 collects temperature data at 100ms intervals and sends it to the main control module. The main control module obtains the real-time water temperature based on the temperature data and compares the real-time water temperature with the target temperature. If the real-time water temperature is less than the target temperature, step S22 continues.

[0049] S23, when the real-time water temperature is not less than the target temperature, obtain the heating time required for the inlet water temperature to rise to the target temperature.

[0050] Specifically, when the real-time water temperature is greater than or equal to the target temperature, it indicates that the water in the heating channel has been heated to vaporization. At this time, the heating module produces high-temperature steam. The timer is read to obtain the heating time required for the water temperature to rise from the inlet temperature to the target temperature. At this time, the actual heating power is calculated based on historical data (such as lookup table method) or calculation formula. This method automatically compensates for the impact of grid voltage fluctuations and heating module performance changes.

[0051] refer to Figure 3Furthermore, in step S3, the specific steps for calculating the preset duty cycle of the water pump module based on the inlet water temperature and the heating time include:

[0052] S31, Based on the heating time, the actual heating power is obtained by looking up a table or by calculation;

[0053] Specifically, the system pre-stores the heating time Δt and the actual heating power P. u Relationships, for example, Δt = 20s, P u =600W; Δt=18s, P u =570W; Δt=22s, P u =620W. Once the heating time required to heat the water from the inlet temperature to the target temperature is obtained, the actual heating power can be obtained by looking up a table. This method can automatically compensate for the effects of grid voltage fluctuations and heater performance changes.

[0054] Alternatively, the actual heating power, P, can also be obtained through calculation. u = (1-K)×P i Where K is the heat loss rate, P i P represents the total input power of the heating module. i K is a fixed value, which can be obtained by looking up a table or by calculation. In the heat loss assessment stage, the heat loss rate is calculated by the ratio of the actual heating power to the theoretical heating power.

[0055] S32, calculate the preset duty cycle of the water pump module based on the inlet water temperature and the actual heating power.

[0056] Specifically, the preset duty cycle is calculated using the following formula:

[0057]

[0058] In the formula, η is the target steam vaporization rate, and P u Q represents the actual heating power (W) of the heating module. max D represents the rated flow rate (kg / s) of the pump module at 100% duty cycle, and C represents the preset duty cycle (%). p The specific heat capacity of water at constant pressure (J / (kg·℃)), T b and T in H represents the boiling point of water (°C) and the inlet water temperature (°C), respectively. v The latent heat of vaporization of water (J / kg).

[0059] In this cleaning system, Q max C p T b H v For a fixed value, P u Ti The cleaning efficiency is affected by environmental factors and is therefore variable. To improve cleaning efficiency, the current working environment needs to be measured, and the target steam vaporization rate η needs to be approached 100% by controlling the water inlet flow rate. This ensures that all water is converted into steam for oil melting, thus maximizing cleaning efficiency. In this embodiment, the target steam vaporization rate η can approach 100%, but it can also be designed to be lower than 100%, for example, η∈[80%,100%), meaning η can be 85%, 90%, or 95%. At this point, the preset duty cycle of the water pump module is calculated according to the formula. Thus, the cleaning preparation stage is completed, and the process moves to the next stage, namely the steam oil melting cleaning stage.

[0060] Additionally, the preset duty cycle can also be achieved through... Calculated. In In the formula, η is the target steam vaporization rate, and Q max Q is the rated flow rate of the pump module at 100% duty cycle. in D represents the inlet water flow rate, and D represents the preset duty cycle. The inlet water flow rate is controlled by adjusting the preset duty cycle of the water pump module. By acquiring the inlet water flow rate through the acquisition module and combining it with the core control target (i.e., steam vaporization rate), the preset duty cycle of the water pump module can be calculated.

[0061] The above formulas reveal all the key variables affecting steam generation efficiency and their interrelationships: P i As an energy source; the heat loss rate K, as the system's "efficiency killer," is directly proportional to the inlet water temperature of the heating channel and the ambient temperature difference. Dry burning will cause it to increase sharply, reducing the energy available for vaporization; inlet water flow rate Q in As a core control variable, the flow rate is inversely proportional to the vaporization rate η. While reducing the flow rate can increase the vaporization rate, dry burning must be strictly avoided. The inlet water temperature, as an environmental variable, increases the actual heat required to heat the water to its boiling point in low winter temperatures, significantly reducing the steam output rate. Therefore, the system needs to sense the inlet water temperature and adjust its strategy accordingly, i.e., calculate the ideal inlet water flow rate and determine the appropriate flow rate based on the rated flow rate Q of the pump module. max This is converted to control the duty cycle, thereby enabling precise control of the water pump module during the working phase.

[0062] Further, in step S4, the specific steps for controlling the water pump module to operate according to the preset duty cycle include:

[0063] S41, to obtain the temperature change trend of water;

[0064] Specifically, after the range hood enters the steam oil-dissolving cleaning stage, the temperature curve exhibits drastic fluctuations due to the temperature sensor being located in the heating channel and the periodic operation of the water pump module. When the water pump module operates, the inflow of cold water causes a momentary drop in temperature within the heating channel; after the water evaporates, the continuous heating by the heating module causes a rapid rise in temperature within the heating channel. To accurately capture the essence of temperature changes, a temperature filtering algorithm is used to detect the temperature trend. This algorithm is as follows: the interval between two water sprays from the water pump module is considered a calculation cycle. At the end of the first spray, the inlet water temperature is lowest, and before the second spray, the inlet water temperature is highest. The time and average temperature of this cycle are statistically analyzed. By continuously statistically analyzing the values ​​for several calculation cycles, the average heating rate of the current stage can be obtained. This method effectively avoids interference from instantaneous fluctuations and can reliably identify the true trend of temperature changes.

[0065] S42, adjust the preset duty cycle according to the temperature change trend, and control the water pump module to work according to the adjusted preset duty cycle.

[0066] Specifically, after the temperature change trend is detected using a temperature filtering algorithm, the main control module adjusts the preset duty cycle of the water pump module according to the temperature change trend. If the temperature change trend is zero, it indicates that the temperature remains unchanged, and the preset duty cycle is not adjusted; the water pump module is controlled to operate according to the original preset duty cycle. If the temperature change trend increases, the preset duty cycle is increased, and the water pump module is controlled to operate according to the increased preset duty cycle. If the temperature change trend decreases, the preset duty cycle is decreased, and the water pump module is controlled to operate according to the decreased preset duty cycle. This achieves adaptive and intelligent adjustment of the water pump module's spray volume based on the temperature change trend, i.e., controlling the water pump module's spray volume based on the actual detected temperature change trend. This allows the steam generator to maximize the steam vaporization rate without dry burning, ultimately achieving efficient, safe, water-saving, and adaptive intelligent cleaning.

[0067] In this embodiment, the specific steps for obtaining the temperature change trend of the water include:

[0068] S411, continuously acquire the average water temperature for multiple calculation cycles, wherein the calculation cycle is the interval between two adjacent water sprays by the water pump module;

[0069] S412 determines the average heating rate based on the average water temperature over multiple calculation cycles;

[0070] S413 determines whether the temperature change trend is zero, increasing, or decreasing based on the average heating rate.

[0071] Specifically, the inlet water temperature in the heating channel is lowest at the end of the previous water spray cycle of the water pump module, and highest before the next water spray cycle begins. By statistically analyzing the interval between two consecutive water spray cycles and the average temperature within that interval, and continuously calculating the values ​​for several cycles, the average temperature rise rate for the current stage can be obtained. Based on this average temperature rise rate, the average temperature increase rate can be calculated. This method effectively avoids interference from instantaneous fluctuations and can reliably identify the true trend of temperature changes.

[0072] The average heating rate R is an extremely sensitive state indicator. During normal vaporization, the temperature reaches dynamic equilibrium slightly above the boiling point, at which point R≈0, indicating that the temperature change trend is zero. When the water volume is slightly low, the temperature shows a slow upward trend, at which point R>0, indicating that the temperature change trend is increasing. When there is a risk of dry burning, the temperature rises sharply, at which point R>>0.

[0073] In this embodiment, if R remains above a positive threshold, it indicates insufficient water supply in the cleaning system, making it prone to dry burning, and confirming an increasing temperature trend. In this case, the main control module increases the preset duty cycle and controls the water pump module according to the increased preset duty cycle to make pumping or spraying water more frequent, increasing the water intake to enhance cooling. If R stabilizes near zero, it indicates the system is in optimal operating condition, confirming a zero temperature trend. In this case, the preset duty cycle remains unchanged, i.e., the preset duty cycle is not adjusted, and the water pump module is controlled according to the original preset duty cycle. If R is negative, it indicates excessive water intake and a low vaporization rate, confirming a decreasing temperature trend. In this case, the main control module decreases the preset duty cycle and controls the water pump module according to the decreased preset duty cycle to reduce the pumping or spraying frequency and decrease the water intake to enhance vaporization. Through this adaptive control based on trend prediction, the cleaning system can continuously fine-tune the preset duty cycle of the water pump module, so that the vaporization rate of its output steam approaches the theoretical optimal value of 100%, thereby dynamically maintaining the most efficient and safest working state.

[0074] Example 2

[0075] The difference between this embodiment and Embodiment 1 is that, before turning on the water pump module and obtaining the inlet water temperature, the cleaning method further includes the following steps:

[0076] S01, obtain the ambient temperature and inherent parameters of the range hood body;

[0077] Specifically, before starting the water pump module, the ambient temperature is detected by the module's temperature sensor during the pre-cleaning stage. The main control module has pre-stored the inherent parameters of the main body 1 of the range hood, including the volume, surface area, and specific heat capacity of the material of the housing assembly 12, as well as the original air mass inside the housing assembly 12, the specific heat capacity of the air at constant pressure, the total mass of the metal parts inside the main body of the range hood, and the specific heat capacity of the steel plate.

[0078] S02, based on the ambient temperature and the inherent parameters, the theoretical energy threshold Q required to melt the oil stains inside the main body of the range hood is calculated using a thermodynamic model. melt .

[0079] Specifically, the thermodynamic model is as follows: According to the law of conservation of energy, the heat brought in by the steam injected by the cleaning system = the heat absorbed by the temperature rise of the gas inside the main cavity of the range hood + the heat absorbed by the temperature rise of the components (mainly sheet metal parts) inside the main cavity of the range hood. The specific formula is as follows: m s ×h s =m i ×c i ×ΔT+m b ×c b ×ΔT, where m s For the mass of injected steam (Kg), h s For the specific enthalpy of steam (100℃ water vapor ≈ 2676 KJ / Kg), m i The original air mass (kg) inside the main body of the range hood, c i Let be the specific heat capacity of air at constant pressure [≈1.005 KJ / (Kg*K)], ΔT be the temperature rise from the initial ambient temperature to the melting oil temperature, and m be the temperature rise. b c is the total mass (kg) of the metal parts inside the main body of the range hood. b The specific heat capacity of the steel plate is approximately 0.46 kJ / (kg*K).

[0080] Among them, h s c i and c b m is a constant i and m b For each range hood, a fixed value is provided; ΔT is related to the current ambient temperature, m. s This is a value that can be controlled by a program. During use, the m value for each type of range hood is first calculated based on its structure. i and m b The value is then used to detect the ambient temperature and calculate ΔT at the start of each cleaning cycle, thus obtaining the desired final result: m s .

[0081] Furthermore, while or after the water pump module is controlled to operate according to the preset duty cycle, the cleaning method further includes the following steps:

[0082] S51, obtain the casing temperature of the main body of the range hood; specifically, estimate the casing temperature based on a thermodynamic model, i.e., using formula m s ×h s =m i ×c i ×ΔT+m b ×cb ×ΔT estimates the chamber temperature.

[0083] S52, when the chamber temperature is higher than the melting oil temperature for a set time, the heating module and the water pump module are turned off, and the fan module is turned on. This melts the oil stains inside the range hood body, improving the cleaning effect.

[0084] The core of the oil melting prediction system is to accurately estimate the preheating state of the tank through a thermal energy accumulation algorithm, thereby completely eliminating reliance on physical temperature sensors and achieving the goal of "minimal water use, lowest energy consumption, and rapid oil dissolution." Throughout the steam oil dissolution cleaning phase, the system executes three core calculations in parallel:

[0085] First, the preset duty cycle D of the water pump module is integrated over time to accurately calculate the cumulative water inflow m. 水 Secondly, obtain and combine the actual heating power P u With inlet water temperature T i The cumulative steam volume m is dynamically calculated and integrated. 汽 via Q total =m 汽 ×H v Estimate the total effective heat energy Q of the main body of the smoke machine. total .

[0086] Then, based on the thermodynamic model and the actual measured ambient temperature T... en Based on the inherent parameters such as the volume, surface area, and specific heat capacity of the range hood housing, the theoretical energy threshold Q required to melt the oil stains is dynamically calculated. melt This means that the system can accurately predict the thermal state inside the enclosure without any enclosure temperature sensors, fundamentally solving traditional problems such as sensor response delay, installation location limitations, and reliability.

[0087] When Q melt Greater than Q total After 60 seconds of continuous operation to completely melt the oil, the system immediately enters the oil-scraping stage. First, the water pump and heating modules are shut off, and the fan module is started, beginning the highest-level oil-scraping for 60 seconds. This maximizes the removal of oil from the fan module's impeller. Finally, the water pump module is turned back on, spraying all remaining water from the heating module onto the fan module's impeller to clean away any remaining oil.

[0088] The core advantage of this method lies in its decision-making based on energy input rather than physical temperature monitoring. This fundamentally avoids problems such as sensor measurement errors, response delays, and installation location limitations, achieving true "sensorless precise temperature control" and "minimum water volume preheating." The energy invested by the system is used precisely for preheating the tank and melting oil stains, maximizing water and electricity savings and significantly reducing hardware costs and system complexity.

[0089] During the cleaning process of a range hood, the casing needs to be heated with steam to a temperature that melts the grease before the oil is spun out. If the temperature is below this melting point, the grease is difficult to remove by spun-out oil. If the temperature is much higher than the melting point, while the grease can be spun out, the improvement in cleanliness is minimal, and the excess heat wastes electricity and water. Therefore, starting the oil spun-out process when the casing temperature is just right for the grease to melt balances cleanliness and energy consumption.

[0090] The above descriptions are merely some embodiments of this application. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this application, and all such modifications and improvements fall within the scope of protection of this application.

Claims

1. A method for cleaning a range hood, characterized in that, The range hood includes a main body, a data acquisition module, a heating module, a water pump module, and a fan module. The cleaning method includes the following steps: Enter cleaning mode, turn on the water pump module and obtain the inlet water temperature; Turn off the water pump module and turn on the heating module to obtain the heating time required to heat the water from the inlet temperature to the target temperature. Calculate the preset duty cycle of the water pump module based on the inlet water temperature and the heating time; The water pump module is controlled to operate according to the preset duty cycle.

2. The cleaning method for a range hood according to claim 1, characterized in that, The specific steps for controlling the water pump module to operate according to the preset duty cycle include: To obtain the temperature change trend of the water; The preset duty cycle is adjusted according to the temperature change trend, and the water pump module is controlled to work according to the adjusted preset duty cycle.

3. The cleaning method for a range hood according to claim 2, characterized in that, The specific steps of adjusting the preset duty cycle according to the temperature change trend and controlling the water pump module to work according to the adjusted preset duty cycle include: If the temperature change trend is zero, the preset duty cycle will not be adjusted, and the water pump module will be controlled to work according to the original preset duty cycle. If the temperature change trend increases, the preset duty cycle is increased, and the water pump module is controlled to work according to the increased preset duty cycle; If the temperature change trend decreases, the preset duty cycle is reduced, and the water pump module is controlled to work according to the reduced preset duty cycle.

4. A cleaning method for a range hood according to claim 2 or 3, characterized in that, The specific steps for obtaining the temperature change trend of the water include: The average water temperature is continuously acquired over multiple calculation cycles, wherein the calculation cycle is the interval between two consecutive water sprays from the water pump module. The average heating rate is determined based on the average water temperature over multiple calculation cycles. Based on the magnitude of the average heating rate, the temperature change trend is determined to be zero, increasing, or decreasing.

5. A cleaning method for a range hood according to claim 1, characterized in that, The specific steps for calculating the preset duty cycle of the water pump module based on the inlet water temperature and the heating time include: Based on the heating time, the actual heating power is obtained by looking up a table or by calculation. The preset duty cycle of the water pump module is calculated based on the inlet water temperature and the actual heating power.

6. A cleaning method for a range hood according to claim 5, characterized in that, The preset duty cycle is calculated using the following formula: In the formula, η is the target steam vaporization rate, and P u Q represents the actual heating power of the heating module. max Q is the rated flow rate of the pump module at 100% duty cycle. in D is the total influent flow rate, C is the preset duty cycle, and D is the total influent flow rate. p T is the specific heat capacity of water at constant pressure. b and T in These represent the boiling point of water and the inlet water temperature, H. v It is the latent heat of vaporization of water.

7. A cleaning method for a range hood according to claim 1, characterized in that, The specific steps for obtaining the heating time required to heat water from the inlet temperature to the target temperature include: The heating timer starts simultaneously with the activation of the heating module; Acquire and determine whether the real-time water temperature is not lower than the target temperature; When the real-time water temperature is not lower than the target temperature, obtain the heating time required for the water temperature to rise from the inlet temperature to the target temperature.

8. A cleaning method for a range hood according to claim 1, characterized in that, The specific steps for activating the water pump module and obtaining the inlet water temperature include: Turn on the water pump module and start recording the pumping time; Determine whether the pumping time has reached the preset pumping time; When the pumping time reaches the preset pumping time, the inlet water temperature of the cleaning system is obtained.

9. A cleaning method for a range hood according to claim 1 or 8, characterized in that, Before activating the water pump module and obtaining the inlet water temperature, the cleaning method further includes the following steps: Obtain the ambient temperature and inherent parameters of the range hood body; Based on the ambient temperature and the inherent parameters, the theoretical energy threshold required to melt the oil stains inside the main body of the range hood is calculated.

10. A cleaning method for a range hood according to claim 1 or 8, characterized in that, While or after the water pump module is controlled to operate according to the preset duty cycle, the cleaning method further includes the following steps: Obtain the casing temperature of the main body of the range hood; When the temperature of the chamber is higher than the temperature of the melting oil for a set period of time, the heating module and the water pump module are turned off, and the fan module is turned on.

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