Fan cleaning method for range hood

Abstract

The present invention relates to a fan cleaning method for a range hood, comprising a preparation stage, a steam cleaning stage, a hot water cleaning stage and a water-spinning stage; the preparation stage enables each module such as a main motor, a stepping motor and a nozzle to enter a preparation state; the steam cleaning stage is to spray steam generated by a steam generator onto blades through a nozzle, and soften and rinse the oil stains on the blades through the control of steam; the hot water cleaning stage is to perform secondary cleaning of the impeller through continuous jets to remove the softened oil stains and the oil stain particles that are decomposed by steam and adhere to the pressure surface of the blades. In this way, while ensuring the cleaning effect, the amount of cleaning water can be effectively utilized to avoid the waste of cleaning water.

Description

Technical Field

[0001] The present invention relates to the technical field of kitchen appliances, and particularly to a method for cleaning a fan of an oil fume extractor. Background Art

[0002] With the continuous progress of the self-cleaning technology of oil fume extractors, steam cleaning or water cleaning has been widely applied in the self-cleaning field of oil fume extractors. Its basic principle is that a steam generator generates steam or a water pump pumps water, and the steam or water is conveyed to a nozzle at the end of a spray pipe. The steam or water is quickly ejected from the nozzle, thereby flushing the impeller to achieve the purpose of cleaning it.

[0003] Currently, most of the self-cleaning systems of oil fume extractors are fixed-nozzle cleaning, and there are also a small number of dynamic cleaning methods. For the fixed-nozzle cleaning method, when cleaning the impeller, only a limited area on the impeller blades can be cleaned, and there will be a large number of areas that cannot be cleaned. In addition, due to the fixed nozzle, in order to achieve a larger cleaning area, usually there are more nozzle openings, which will inevitably cause the pressure of the water or steam ejected from the nozzle to become smaller. And for the cleaning process of areas with heavier oil stains and areas with lighter oil stains, the cleaning intensity is the same. Therefore, after the area with lighter pollution is cleaned, the nozzle will still clean this area, resulting in a waste of water volume. For the existing dynamic cleaning on the market, although it can clean the entire blade, there is still a waste of cleaning water volume during the cleaning process. Summary of the Invention

[0004] Based on this, in view of the problem of cleaning water volume, it is necessary to provide a method for cleaning a fan of an oil fume extractor to effectively utilize the cleaning water volume and avoid waste of the cleaning water volume.

[0005] The present invention provides a method for cleaning a fan of an oil fume extractor, including the steps of:

[0006] a. Preparation stage:

[0007] a1. Start the main motor to drive the impeller to rotate, and limit the impeller to rotate at a first rotational speed N1;

[0008] a2. Start the stepper motor to drive the nozzle to move to the initial cleaning position;

[0009] a3. Start the water pump to inject water into the steam generator to a preset position, and after the water injection is completed, detect the initial water temperature T0 in the steam generator through a temperature sensor;

[0010] b. Steam cleaning stage: Spray the steam generated by the steam generator onto the blades of the impeller through the nozzle, and set the operation time of the steam cleaning stage as t1, t1≥1T, where T is the time for the nozzle to reciprocate once along the axial direction of the impeller;

[0011] c. Hot water cleaning stage, in which hot water is sprayed onto the impeller blades through a nozzle, and the running time of the hot water cleaning stage is set to t2, t2 ≥ 0.5T;

[0012] d, water-throwing stage;

[0013] d1, the nozzle is driven by the stepper motor to move to the initial cleaning position and then stops running;

[0014] d2, the main motor is operated to drive the impeller to rotate at a second speed N2 and the operating time is t3, wherein N2>N1.

[0015] In the above-mentioned fan cleaning method for range hoods, the preparation stage can put various modules such as the main motor, stepper motor and nozzle into a preparation state, so that the steam cleaning stage can proceed smoothly and quickly, and filling the steam generator with water in advance can avoid the phenomenon of dry burning without water and causing overheating protection in the subsequent stage; the steam cleaning stage is to spray the steam generated by the steam generator onto the blades through the nozzle, and soften and rinse the oil on the blades through the control of steam. The steam cleaning stage can ensure that the impeller can be cleaned back and forth at least twice, thereby ensuring the cleaning effect; the hot water cleaning stage is to perform a secondary cleaning of the impeller through continuous jets to remove the softened oil and the oil particles that are decomposed by steam and stuck to the pressure surface of the blades, so that the cleaning effect can be ensured while fully and effectively utilizing the cleaning water to avoid waste of cleaning water.

[0016] In one embodiment, in step a2, the step of:

[0017] The water temperature is continuously monitored by the temperature sensor for no less than 10 seconds.

[0018] Such a setting can avoid insufficient temperature diffusion, which may cause the detected temperature to be inconsistent with the actual water temperature due to the influence of the cavity, thereby improving the accuracy of the initial water temperature T0 detection.

[0019] In one embodiment, in step a1, the first rotation speed N1 satisfies: 30 r / min≤N1≤350 r / min.

[0020] Such an arrangement can reduce water waste while ensuring a wide coverage of the blade cleaning surface.

[0021] In one embodiment, in step b, the step of:

[0022] b1, operate the heating module to heat the water in the steam generator, and simultaneously detect the temperature T of the water in the steam generator X , and record the heating module running time t x , t x≤t1;

[0023] b2, Determination condition 1: Temperature T X Is it greater than or equal to the first preset temperature T1, 100°C ≤ T1 ≤ 135°C;

[0024] b3, If the result of determination condition 1 is yes, operate the stepper motor to drive the nozzle to reciprocate and spray steam towards the impeller;

[0025] b4, If the result of determination condition 1 is no, then execute determination condition 2: Operating time t x Is it greater than or equal to the preheating time t4;

[0026] If the result of determination condition 2 is yes, operate the stepper motor to drive the nozzle to reciprocate and spray steam towards the impeller;

[0027] If the result of determination condition 2 is no, loop and execute steps b1 to b4.

[0028] Set like this, detecting the temperature T X is to ensure that when the nozzle starts to move, the nozzle has generated steam, avoiding cleaning dead corners at the starting position; for the operating time t of the heating module x Making a judgment is to avoid continuous heating of the heating module caused by a temperature sensor failure.

[0029] In one embodiment, after step b4, it further includes the step:

[0030] b5, Control the water pump to supply water to the steam generator intermittently in a cycle.

[0031] Set like this to ensure that steam can be continuously and normally generated in the steam generator.

[0032] In one embodiment, in step b5, the intermittent cycle mode of the water pump is: operate for s seconds and stop for w seconds, where , where s ranges from 0.4 seconds to 2.6 seconds, Q is the actual flow rate of the water pump, in g / s, and P is the power of the heating module, in W.

[0033] Set like this so that the steam generator can adapt to different initial water temperatures to ensure continuous steam generation and maintain the steam purity at a certain level.

[0034] In one embodiment, in step b5, when the initial water temperature T0 is between 10 degrees and 40 degrees, the intermittent cycle mode of the water pump is: operate for s seconds and stop for w seconds, satisfying: , where s ranges from 0.4 seconds to 2.6 seconds, Q is the actual flow rate of the water pump, in g / s, and P is the power of the heating module, in W.

[0035] With such a setting, when adding normal temperature water generally, the running time and stopping time of the water pump can be determined through the above formula to ensure that steam can be continuously and normally generated in the steam generator.

[0036] In one embodiment, in step b4, the preheating time t4 satisfies: , where k ranges from 3 seconds to 5 seconds, V is the volume of water in the cavity of the steam generator in grams (g), and P is the power of the heating module in watts (W).

[0037] With such a setting, the preheating time t4 can be determined according to the temperature of the actually added water to widely adapt to different water temperatures.

[0038] In one embodiment, in step c, the following steps are further included:

[0039] c1, determine whether the initial water temperature T0 is greater than the second preset temperature T2, T2 = 90 - P / 5Q, where Q is the actual flow rate of the water pump in grams per second (g / s) and P is the power of the heating module in watts (W);

[0040] c2, if T0 > T2, start the water pump to run continuously, and drive the nozzle to reciprocate and spray hot water towards the blades through the stepper motor until all the water in the water tank is used up, and set the temperature when the water temperature in the steam generator is stable as T3;

[0041] c3, if T0 ≤ T2, run the heating module, the water pump runs continuously, and drive the nozzle to reciprocate and spray hot water towards the blades through the stepper motor until all the water in the water tank is used up, and set the temperature when the water temperature in the steam generator is stable as T3.

[0042] With such a setting, it is to avoid the problem of steam generation in the hot water stage when the user uses hot water with too high a temperature. At the same time, when the user uses normal temperature water, it is ensured that the water ejected from the nozzle is hot water with a certain temperature to better improve the efficiency of cleaning oil stains.

[0043] In one embodiment, in step c2 or step c3, in the step of continuously running the water pump to inject water into the steam generator until all the water in the water tank is used up, the following are further included:

[0044] c41, continuously run the water pump to inject water into the steam generator;

[0045] c42, determine whether the temperature T X detected by the temperature sensor in the steam generator is greater than the third preset temperature T4, T1 ≥ T4 ≥ T3 + 10°C;

[0046] If so, determine that all the water in the water tank is used up, and the water pump, heating module, and stepper motor stop running synchronously, and the hot water stage ends;

[0047] If not, execute steps c41 and c42.

[0048] With such an arrangement, it is possible to determine whether the water in the water box is exhausted by detecting a drastic change in water temperature or a drastic change in water pump current.

[0049] In one embodiment, between step b and step c, the method further includes:

[0050] Step e: static phase, set the static phase running time to t5,

[0051] Stop running the water pump and heating module;

[0052] The nozzle is driven by a stepper motor to move to the initial cleaning position and then stop;

[0053] The main motor drives the impeller to continuously run at the first speed within a time period of t5; t5 is 60 seconds to 180 seconds.

[0054] This arrangement allows the water vapor in the steam to fully penetrate into the oil stains on the blades to soften the oil stains, while the moving nozzle is driven by the stepper motor to move to the initial cleaning position; and, t5 can ensure that the stepper motor can complete the return to its original position within 60 seconds to 180 seconds while preventing the oil stains from cooling down again.

[0055] In one embodiment, in step d2, the second rotation speed N2 satisfies: 600 r / min≤N2≤1100 r / min.

[0056] With this arrangement, the air flow speed is faster, thereby ensuring the drying effect and shortening the time of the water-drying stage.

[0057] In one embodiment, in step d2, it includes:

[0058] The main motor should run for no less than 180 seconds.

[0059] This arrangement ensures that the moisture on the impeller surface is completely removed, thereby ensuring the drying effect.

[0060] In one embodiment, the time T for the nozzle to reciprocate once along the axial direction of the impeller satisfies: 60s≤T≤120s.

[0061] Such an arrangement can reduce water waste while ensuring that the blades are cleaned.

[0062] Compared with the prior art, the advantages of the present invention are:

[0063] By optimizing the cleaning time control of the steam cleaning stage and the hot water cleaning stage, the steam generated by the steam generator is sprayed onto the blades through the nozzle during the steam cleaning stage, and the oil on the blades is softened and rinsed through steam control. The steam cleaning stage can ensure that the impeller can be cleaned back and forth at least twice, thereby ensuring the cleaning effect; the hot water cleaning stage performs a secondary cleaning of the impeller through continuous jets to remove the softened oil and the oil particles that are decomposed by steam and stuck to the pressure surface of the blades. This ensures that the cleaning effect can be ensured while fully and effectively utilizing the cleaning water and avoiding waste of cleaning water. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 A flow chart of a fan cleaning method for a range hood according to an embodiment of the present invention;

[0065] Figure 2 for Figure 1 Flowchart of the preparation phase;

[0066] Figure 3 for Figure 1 Flow chart of the steam cleaning phase;

[0067] Figure 4 for Figure 1 Flow chart of the resting phase;

[0068] Figure 5 for Figure 1 Flow chart of the hot water cleaning phase;

[0069] Figure 6 for Figure 1 Flowchart of the water-spinning phase. DETAILED DESCRIPTION

[0070] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0071] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0072] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0073] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] Currently, most of the self-cleaning systems of range hoods are fixed nozzle cleaning, and there are also a small number of dynamic cleaning methods. For the fixed nozzle cleaning method, when cleaning the impeller, only a limited area on the impeller blades can be cleaned, and there will be a large number of areas that cannot be cleaned. In addition, since the nozzle is fixed, in order to achieve a larger cleaning area, usually there are more openings in the nozzle, which will inevitably cause the pressure of the water or steam ejected from the nozzle to become smaller. And during the cleaning process, the cleaning intensity for areas with heavier oil stains and areas with lighter oil stains is the same. Therefore, after the area with lighter pollution is cleaned, the nozzle will still clean this area, resulting in a waste of water volume. For the existing dynamic cleaning on the market, although it can clean the entire blade, there is still a waste of cleaning water volume during the cleaning process.

[0075] In a self - cleaning range hood for dynamic cleaning, the range hood includes a housing, a fan, a cleaning medium supply member, a driving device, a water tank, a water pump and a steam generator. The fan is disposed in the housing and includes a volute, an impeller disposed in the volute, and a main motor for driving the impeller to rotate. A plurality of axially - extending blades are circumferentially and spacedly arranged on the impeller. The water in the water tank can be pumped into the steam generator by the water pump. The steam generator includes a temperature sensor and a heating module. The temperature sensor is used to detect the temperature in the steam generator, and the heating module is used to heat the liquid in the steam generator. The driving device can be a stepper motor or the like and is used to drive the cleaning medium to reciprocate. The cleaning medium supply member has a penetrating portion that can extend into the volute, and a nozzle for ejecting the cleaning medium is provided on the end surface of the penetrating portion.

[0076] In one embodiment, a relief hole is provided in the annular wall of the volute at the position of the volute tongue. The cleaning medium supply member is an annular pipe and can reciprocate within a certain angular range around a certain axis. In the working state, the nozzle extends into the volute and faces the blades of the impeller, and the ejection area of the cleaning medium ejected from the nozzle to the blades reciprocates between the two axial ends of the impeller, realizing the cleaning of the impeller. The cleaning range of the cleaning medium covers the entire impeller. In the non - working state, the nozzle withdraws from the volute to prevent the outlet of the penetrating portion from being blocked.

[0077] In another embodiment, the relief hole can also be provided in the end wall of the volute, and the cleaning medium supply member is an elastic strip - shaped pipe. The driving device also includes a transmission structure such as a gear - rack. When cleaning is required, the driving device drives the cleaning medium supply member to move backward relative to the volute so that the nozzle extends into the volute and faces the blades of the impeller. In the working state, the cleaning medium supply member extending into the volute will restore its strip - shaped structure under its own elastic force. By periodically changing the rotation direction of the driving device, the ejection area of the cleaning medium ejected from the nozzle to the blades can reciprocate between the two axial ends of the impeller, realizing the cleaning of the impeller. The cleaning medium supply member exposed outside the volute is arranged along the bending channel under the limitation of the limiting sleeve, reducing the occupied space. Of course, in other embodiments, the cleaning medium supply member can also be in other reciprocating motion modes, as long as it can ensure that the ejection area of the cleaning medium ejected from the nozzle to the blades can reciprocate between the two axial ends of the impeller, and no specific limitation is made here.

[0078] To solve the above problems, as Figures 1 to 6 shown, the present invention provides a method for cleaning the fan of a range hood, which is used to effectively utilize the cleaning water volume and avoid waste of the cleaning water volume. It can be understood that this fan cleaning method can be but is not limited to being used in the self - cleaning range hood with the above - mentioned structure to complete the fan cleaning, and no specific limitation is made here.

[0079] like Figure 1 As shown, the fan cleaning method can include five stages, specifically:

[0080] S100 preparation stage;

[0081] S200 steam cleaning stage;

[0082] S300 static stage;

[0083] S400 hot water cleaning stage;

[0084] S500 water-shedding stage.

[0085] Among them, whether to enter the S300 static stage can be selected according to specific circumstances.

[0086] like Figure 2 As shown, the S100 preparation stage includes:

[0087] S110: starting the main motor to drive the impeller to rotate, and limiting the impeller to rotate at a first speed N1;

[0088] S120 starts the stepper motor to drive the nozzle to move to the initial cleaning position;

[0089] S130 starts the water pump to inject water into the steam generator to a preset position, and after the water injection is completed, detects the initial water temperature T0 in the steam generator through the temperature sensor.

[0090] In step S100, the preparation stage mainly allows the self-cleaning system to enter a cleaning state, and allows various modules such as a main motor, a stepper motor, a nozzle, a water pump and a steam generator to enter a preparation state, so that the steam cleaning stage can proceed smoothly, safely and quickly.

[0091] In step S110, the first rotational speed N1 of the main motor satisfies: 30 r / min ≤ N1 ≤ 350 r / min. Since the rotational speed of the main motor is related to the rotational speed of the stepper motor and the diffusion width of the jet, when the rotational speed of the stepper motor is too high and the rotational speed of the main motor is too low, for example, when N1 < 30 r / min, the cleaning marks on the blade surface will show a spiral shape, and there will be a phenomenon of incomplete cleaning; when the first rotational speed N1 of the main motor is too high, for example, when N1 > 350 r / min, the jet will be blocked and reflected by the next blade when flowing through the gap between the blades, and the jet cannot reach the pressure surface of the target blade, while causing water splashing and waste. To avoid the difficulty in covering the blade cleaning surface due to too low a first rotational speed N1 of the main motor, or the waste of water caused by excessive overlap of the jets due to too high a first rotational speed N1 of the main motor, the first rotational speed N1 of the main motor is limited to 30 r / min ≤ N1 ≤ 350 r / min, so as to reduce the waste of water while ensuring a wide coverage of the blade cleaning surface. For example, for a range hood in which the stepper motor drives the nozzle to perform a curvilinear reciprocating motion, the rotational speed of its stepper motor can be coordinated with the first rotational speed N1 of the main motor. For example, the stepper motor can be set to rotate an angle of 91.2 degrees within 30 to 60 seconds, driving the nozzle to move along the axial direction of the impeller from one end to the other end.

[0092] In step S120, the stepper motor driving the nozzle to move to the initial cleaning position means that the stepper motor drives the nozzle to move from the retracted position to the position where cleaning starts. When not in use, the nozzle will retract from the housing to the retracted position, and there is mechanical positioning at the retracted position to prevent the nozzle from retracting too much and to facilitate program recognition and positioning. During the preparation stage, the nozzle first moves to the initial cleaning position to avoid wasting water due to an idle stroke at the start of cleaning. When the nozzle makes a reciprocating rotational motion, the positioning of the initial cleaning position is controlled by the angular displacement of the nozzle through time.

[0093] In step S130, the water pump pumps the water in the water tank into the steam generator and fills the steam generator with water. Filling the steam generator with water means filling at least the cavity of the heating module. In this process, it can be controlled by the water filling time of the water pump. The water filling time of the water pump is related to the internal cavity of the steam generator and the flow rate of the water pump. Based on the ratio of the volume of the heating module cavity to the flow rate, the specific water filling time of the water pump can be determined by fine-tuning through experiments. Since preheating may be required during the steam cleaning stage, if preheating and flushing are carried out simultaneously, a small-flow water pump cannot be filled in a short time. To avoid dry burning of the heating module without water and resulting in overheat protection, it is necessary to fill the steam generator with water in advance. Also, the temperature sensor for detecting the initial water temperature T0 in the steam generator also requires the steam generator to be filled with water. The temperature sensor detects the initial water temperature T0 of the water added by the user to facilitate the control of the subsequent steam cleaning stage and hot water cleaning stage.

[0094] Among them, when the water injection is completed, the initial water temperature T0 is detected through the temperature sensor, and the temperature sensor continuously monitors the water temperature for no less than 10 seconds and records the initial water temperature T0, so as to avoid the temperature of the water in the cavity of the steam generator not being fully diffused, resulting in the detected temperature being inconsistent with the actual water temperature due to the influence of the cavity, thereby improving the accuracy of the detection of the initial water temperature T0.

[0095] As Figure 3 shown, the S200 steam cleaning stage is as follows: The steam generated by the steam generator is sprayed onto the blades of the impeller through the nozzle, and the running time of the steam cleaning stage is set to t1, t1≥1T, where T is the time for the nozzle to reciprocate once along the axial direction of the impeller.

[0096] In the steam cleaning stage, the steam generated by the steam generator is mainly sprayed onto the blades through the nozzle, and the oil stains on the blades are softened and rinsed by controlling the steam. In this way, it can be ensured that the impeller can be cleaned at least back and forth once, thus ensuring the cleaning effect. On the premise that the water volume permits, the running time t1 of the steam cleaning stage can be extended, and after the steam cleaning stage, the remaining water volume can still ensure that the hot water cleaning stage can clean the impeller at least once. Among them, the time T for the nozzle to reciprocate once along the axial direction of the impeller satisfies: 60s≤T≤120s. If the time T for the nozzle to reciprocate once is too short, it may cause the impeller to be not cleaned cleanly, while if the time T for the nozzle to reciprocate once is too long, it may cause too much water to be wasted. Therefore, the time T for the nozzle to reciprocate once is limited to 60s≤T≤120s to reduce the waste of water volume while ensuring that the blades are cleaned cleanly. Since the impact force of the steam is relatively large, the steam temperature is high, and the water consumption is small, it is beneficial to save water and is also beneficial to softening and cleaning the surface oil stains. Therefore, a steam cleaning stage with a longer running time t1 can be set.

[0097] Specifically, the S200 steam cleaning stage includes:

[0098] S210 operates the heating module to heat the water in the steam generator and synchronously detects the temperature T of the water in the steam generator X , and records the running time t of the heating module x , t x ≤t1;

[0099] S220 determination condition 1: Whether the temperature T X is greater than or equal to the first preset temperature T1, 100℃≤T1≤135℃;

[0100] S230 If the result of determination condition 1 is yes, the stepping motor is operated to drive the nozzle to reciprocate and spray steam towards the impeller;

[0101] If the determination condition 1 is false, then execute determination condition 2: the running time t x Is it greater than or equal to the preheating time t4;

[0102] If the result of determination condition 2 is yes, then run the stepper motor to drive the nozzle to reciprocate and spray steam towards the impeller;

[0103] If the result of determination condition 2 is no, then loop and execute steps S210 to S240.

[0104] S250 controls the water pump to intermittently supply water to the steam generator in a cycle.

[0105] In steps S210 to S240, the temperature T is detected X To ensure that when the nozzle starts to move, the nozzle has generated steam, avoiding the situation that the nozzle has started to move but no steam has been generated yet, resulting in some positions on the blade not being cleaned, thus creating a cleaning dead angle at the starting position. Generally, when the temperature T X Is between 100 - 135 °C, steam can be generated. Therefore, the first preset temperature T1 satisfies 100 °C < T1 < 135 °C. When T X ≥ T1, that is, enter step S250. Of course, according to the actual situation, when the steam generator is filled with water, by measuring the resistance value of the temperature sensor when steam starts to be generated and referring to the temperature curve of the corresponding model characteristics, the first preset temperature T1 can be determined. At the same time, to avoid continuous heating of the heating module due to temperature sensor failure, while detecting the temperature T X The running time t of the heating module is also judged x When the running time t of the heating module x Reaches the preheating time t4, steam has also been generated, so it can enter step S250.

[0106] Among them, when the steam generator is filled with water, the preheating time t4 is usually the time from the start of heating to the generation of steam, and then add 3 seconds - 5 seconds to ensure that steam has been generated. When the preheating time t4 is a constant value, the preheating time t4 can be determined with water at about 20 °C. To avoid program problems caused by temperature differences, at this time, the user can only add normal temperature water used in daily life to the water tank, and cannot use heated hot water. When the user uses hot water for cleaning, due to the too high water temperature, the steam purity in the steam cleaning stage will increase significantly, resulting in problems such as disconnection of pipeline interfaces or even pipeline bursting. And, in the subsequent hot water cleaning stage, steam will also continue to be sprayed, and the effect of removing oil stains is poor; at the same time, due to the large temperature differences between winter and summer, and between the north and the south, the steam purity generated by constant temperature water at different temperatures for the constant preheating time t4 is different. When the water temperature is low, the steam purity and intensity decrease, which will also lead to poor cleaning effects.

[0107] Therefore, in order to widely adapt to different water temperatures, the preheating time t4 can also be calculated according to the actual situation. The preheating time t4 satisfies: , where k ranges from 3 seconds to 5 seconds, V is the water volume in the cavity of the steam generator, with the unit of g, and P is the power of the heating module, with the unit of W. At this time, the preheating time t4 can be determined according to the temperature of the actually added water.

[0108] In step S250, during the steam cleaning stage, the stepper motor starts and reciprocates between the starting position and the ending position of the cleaning. Since there is a limit on the power of the heating module, the rate of steam generation by the steam generator is less than the rate at which the water pump pumps water into the steam generator. To ensure continuous and normal steam generation in the steam generator, the water pump needs to operate intermittently, that is, it operates for s seconds and stops for w seconds. The specific times of operating for s seconds and stopping for w seconds are related to the water pump flow rate and the power of the heating module. s is mainly related to the water pump flow rate and the steam purity, and the steam purity will affect the water consumption within s + w seconds. Within s seconds, it is necessary to ensure that the water pumped into the steam generator by the water pump once does not come out at the nozzle. Thus, the specific value of s can be determined. w needs to be determined according to the actual steam generation situation. For example, when adding normal temperature water, the range of normal temperature water T0 is usually between 10 degrees and 40 degrees. Operating for s seconds and stopping for w seconds, it satisfies: , where s ranges from 0.4 seconds to 2.6 seconds, Q is the actual flow rate of the water pump, with the unit of g / s, and P is the power of the heating module, with the unit of W. That is, the range of w can be calculated through the above formula. When the operating time s is determined, the stopping time w determines the steam purity and the steam impact intensity. Therefore, the intermittent operation mode of the water pump is set through the above relationship to generate continuous steam and keep the steam purity at a certain level.

[0109] To improve the versatility of this application, the user can also add hot water by themselves. According to the initial water temperature T0 of the added water by the user, the intermittent operation mode of the water pump is set, that is, it operates for s seconds and stops for w seconds, to maintain a constant steam mode. And it satisfies: , where s ranges from 0.4 seconds to 2.6 seconds, Q is the actual flow rate of the water pump, with the unit of g / s, and P is the power of the heating module, with the unit of W. In this way, on the one hand, the versatility of the fan cleaning method of this application is improved, and on the other hand, by limiting the relationship between s and w, it is beneficial to generate continuous steam and keep the steam purity at a certain level.

[0110] As Figure 4 shown, the S300 static stage includes:

[0111] S310 Stop operating the water pump and the heating module;

[0112] S320 Drive the nozzle to move to the initial cleaning position by the stepper motor and then stop;

[0113] The S330 drives the impeller through the main motor to continuously operate at the first rotational speed within the time t5; t5 is 60 seconds to 180 seconds.

[0114] In step S300, the static stage is mainly to allow the water vapor in the steam generated in the steam cleaning stage to fully penetrate into the blade oil stains, so as to soften the oil stains. At the same time, the stepping motor drives the moving nozzle to move to the initial cleaning position to prepare for the cleaning in the hot water cleaning stage. Within 60 seconds to 180 seconds, t5 can avoid the oil stains from cooling again while ensuring that the stepping motor can complete the homing and the nozzle returns to the initial cleaning position. Since the oil stains on the blades can also be softened in the steam cleaning stage, and the cleaning work can be directly started in the hot water cleaning stage even if the nozzle does not return to the initial cleaning position, therefore, it can be selected according to needs whether to enter the static stage or directly enter the hot water cleaning stage.

[0115] As Figure 5 shown, the S400 hot water cleaning stage is: In the hot water cleaning stage, hot water is sprayed onto the blades of the impeller through the nozzle, and the running time of the hot water cleaning stage is set as t2, t2≥0.5T.

[0116] In step S400, the hot water cleaning stage is mainly to perform secondary cleaning on the impeller through continuous jet flow to remove the softened oil stains and the oil stain particles decomposed by steam sticking to the pressure surface of the blade.

[0117] Specifically, the S400 hot water cleaning stage includes:

[0118] S410 determines whether the initial water temperature T0 is greater than the second preset temperature T2, T2 = 90 - P / 5Q, where Q is the actual flow rate of the water pump, in g / s, and P is the power of the heating module, in W;

[0119] S420 If T0 > T2, if T0 > T2, then start the water pump to continuously operate, and drive the nozzle to reciprocate and spray hot water towards the blades through the stepping motor until all the water in the water tank is used up, and set the temperature when the water temperature in the steam generator is stable as T3;

[0120] S430 If T0 ≤ T2, then operate the heating module, the water pump continuously operates, and drive the nozzle to reciprocate and spray hot water towards the blades through the stepping motor until all the water in the water tank is used up, and set the temperature when the water temperature in the steam generator is stable as T3.

[0121] In steps S410 to S430, first, it is determined whether the initial temperature T0 is greater than the second preset temperature T2. If T0 > T2, the heating module does not operate to prevent the temperature inside the steam generating device from becoming too high after the heating module is turned on, which may cause steam to be generated, resulting in the nozzle still spraying steam during the hot water cleaning stage and affecting the cleaning effect. If T0 is less than or equal to T2, the heating module needs to be started to ensure that the water sprayed by the nozzle is hot water, thereby improving the oil removal effect. Moreover, during the hot water cleaning stage, different initial water temperatures T0 can also be adapted.

[0122] It is worth mentioning that the temperature T3 when the water temperature in the steam generator is stable refers to the temperature corresponding to the water temperature in the steam generator remaining unchanged for a relatively long period of time. For example, in step S430, the temperature T3 can be the temperature after the heating module is started and heated for 10 seconds to avoid the influence of a lower temperature during the initial heating stage. After the water pump operates for a period of time, since the power of the water pump and the power of the steam generator remain unchanged, the water temperature will remain at a stable temperature for a certain period of time. For example, in step S440, the temperature T3 can be the water temperature in the steam generator after the water pump operates for a specific time to avoid the influence of the water temperature drop caused by the steam generator housing or other devices.

[0123] During the hot water cleaning stage, all the water in the water tank needs to be used up, and the cleaning time should be guaranteed to be at least greater than or equal to 0.5T. As long as this is ensured, the impeller can be cleaned back and forth at least once, thereby guaranteeing the cleaning effect. When the water volume is sufficient, the cleaning time is preferably greater than or equal to 1T.

[0124] In step S420 or S430, during the step of continuously operating the water pump to inject water into the steam generator until all the water in the water tank is used up, it further includes:

[0125] S441 Continuously operate the water pump to inject water into the steam generator;

[0126] S442 Determine whether the current of the water pump is less than the preset value or determine whether the temperature T X detected by the temperature sensor in the steam generator is greater than the third preset temperature T4, where T1 ≥ T4 ≥ T3 + 10°C;

[0127] If so, it is determined that all the water in the water tank has been used up, and the water pump, heating module, and stepper motor stop running synchronously, and the hot water stage ends;

[0128] If not, execute steps S441 and S442.

[0129] In step S442, when the water is used up, the water pump current will drop significantly and the temperature sensor will increase significantly. Therefore, it is possible to determine whether the water in the water box is used up by detecting a sharp change in water temperature or a sharp change in water pump current. X When the temperature is greater than the third preset temperature T4 and satisfies T1≥T4≥T3+10°C, it means that all the water in the water tank is used up. X Select the value within 3-5 seconds of the rising section to determine the temperature in the steam generator measured by the temperature sensor to avoid misjudgment. When determining the third preset temperature, select a temperature greater than or equal to (T3+10) and less than or equal to T1 as the threshold. For example, T4 can be set at about 100°C. In other embodiments, it is also possible to determine whether the water pump current value has dropped significantly by the corresponding return signal within 10 seconds before and after the actual measurement ends, and select the signal segment with obvious fluctuations within 10 seconds after the end as the threshold, which will not be repeated here.

[0130] like Figure 6 As shown, the S500 water-shedding stage includes:

[0131] S510 uses a stepper motor to move the nozzle to the initial cleaning position and then stops running;

[0132] S520: The main motor is operated to drive the impeller to rotate at a second speed N2 for a running time of t3, wherein N2>N1.

[0133] In step S500, the water-drying stage is mainly used to remove the water on the surface of the impeller, and use the airflow to dry the impeller to remove the surface moisture, so as to avoid the problems of rusting of the impeller and shedding of the coating due to the high moisture environment. Among them, the second speed N2 satisfies: 600r / min≤N2≤1100r / min, and the airflow speed is fast, so as to ensure the drying effect and shorten the time of the water-drying stage. Optionally, in other embodiments, 1000r / min≤N2≤1100r / min. In addition, the main motor is operated for a duration of not less than 180 seconds to further ensure that the moisture on the impeller surface is completely removed, thereby ensuring the drying effect.

[0134] Furthermore, the double-inlet impeller divides the length W in the axial direction of the impeller into W1 and W2 at the position of the middle disc, where the longer section W1 is set as the main air inlet section; W2 is the auxiliary air inlet section. Since the working principle of the grading system is the same, the oil stain distribution law is the same; for the double-inlet impeller, the oil stain on the main air inlet section per unit area is slightly more serious and the oil quantity is more than that on the auxiliary air inlet section. From the air inlet direction to the middle disc position, the oil stain generally shows a gradually increasing trend. Among them, the two end regions in the axial direction of the impeller are the regions with less pollution, and the lengths respectively account for about 1 / 5 of W1 and W2; obvious oil stain pollution appears in the middle region in the axial direction of the impeller, and the pollution degree is serious; for the single-inlet impeller, the front 1 / 5 of the air inlet is less polluted and the rear end is seriously polluted.

[0135] Therefore, during cleaning, different cleaning modes with different intensities can be matched according to the pollution degree of the oil stain, and the areas with serious pollution should be focused on cleaning to reduce the repeated cleaning in the lightly polluted areas. When the cleaning in the steam cleaning stage and the hot water cleaning stage can complete more than 1T of cleaning, the heavily polluted areas can be focused on cleaning to avoid wasting water by repeatedly cleaning in the lightly polluted areas. Since the rotation direction needs to be reversed at the starting and ending positions of cleaning, there is also a short pause, which will also waste water in the lightly polluted areas. Therefore, for efficient cleaning, the lightly polluted areas at the head and tail are only cleaned 1-2 times, and the other water cleaning is used for cleaning the heavily polluted areas. Control the rotation of the stepper motor and concentrate on rotating back and forth in the heavily polluted areas. To strengthen the cleaning of the heavily polluted areas, in addition to concentrating on rotating back and forth in this area, the angular velocity of the nozzle can be reduced by 10%-20% to reduce the gap in the high-pressure area at the center of the jet flow and partially overlap the diffusion areas, so as to improve the cleaning intensity. In the steam cleaning stage, the steam purity can also be improved in a short time by extending the stop time w and increasing the steam impact pressure to strengthen the steam cleaning. Thus, water can be further effectively utilized to achieve efficient cleaning and improve the cleaning rate.

[0136] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0137] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. A method for cleaning a fan of a range hood, characterized in that, Including the steps: a. Preparation stage: a1. Start the main motor to drive the impeller to rotate, and limit the impeller to rotate at the first rotational speed N1; a2. Start the stepper motor to drive the nozzle to move to the initial cleaning position; a3. Start the water pump to inject water into the steam generator to a preset position, and after the water injection is completed, detect the initial water temperature T0 in the steam generator through the temperature sensor; b. Steam cleaning stage, inject the steam generated by the steam generator onto the blades of the impeller through the nozzle, set the operation time of the steam cleaning stage as t1, t1≥1T, where T is the time for the nozzle to reciprocate once along the axial direction of the impeller; Control the water pump to supply water to the steam generator intermittently in a cycle, and the intermittent cycle mode satisfies: the water pump intermittent cycle mode is: running for s seconds and stopping for w seconds, where, , where s ranges from 0.4 seconds to 2.6 seconds, Q is the actual flow rate of the water pump in g / s, and P is the power of the heating module in W; c. Hot water cleaning stage, in the hot water cleaning stage, spray hot water onto the blades of the impeller through the nozzle, set the operation time of the hot water cleaning stage as t2, t2≥0.5T; d. Water draining stage; d1. Stop running after driving the nozzle to move to the initial cleaning position by the stepper motor; d2. Run the main motor to drive the impeller to rotate at the second rotational speed N2 for a running time of t3, where N2>N1.

2. The fan cleaning method according to claim 1, wherein In step a3, it further includes the steps: Continuously monitor the water temperature by the temperature sensor for no less than 10 seconds, and record the initial water temperature T0.

3. The fan cleaning method according to claim 1, characterized in that, In step a1, the first rotational speed N1 satisfies: 30r / min≤N1≤350r / min.

4. The fan cleaning method according to claim 1, characterized in that, In step b, it further includes the steps: b1, operate the heating module to heat the water in the steam generator and simultaneously detect the temperature T of the water in the steam generator X , and record the operation time t of the heating module x , t x ≤t1; b2, Determination condition 1: Temperature T X whether it is greater than or equal to the first preset temperature T1, 100°C ≤ T1 ≤ 135°C; b3. If the result of determination condition 1 is yes, run the stepper motor to drive the nozzle to reciprocate and spray steam towards the impeller; b4, if the determination condition 1 is false, then execute determination condition 2: whether the running time t x is greater than or equal to the preset time t4; If the result of determination condition 2 is yes, run the stepper motor to drive the nozzle to reciprocate and spray steam towards the impeller; If the result of determination condition 2 is no, loop to execute steps b1 to b4.

5. The fan cleaning method according to claim 1, wherein When the initial water temperature T0 is between 10 degrees and 40 degrees, the pump circulation interval mode is: running for s seconds and stopping for w seconds, and it satisfies: , where s ranges from 0.4 seconds to 2.6 seconds, Q is the actual flow rate of the pump, with the unit of g / s, and P is the power of the heating module, with the unit of W.

6. The fan cleaning method according to claim 4, wherein, In step b4, the preheating time t4 satisfies: , where k ranges from 3 seconds to 5 seconds, V is the water volume in the cavity of the steam generator, in grams, and P is the power of the heating module, in watts.

7. The fan cleaning method according to claim 4, characterized in that, In step c, it further includes the steps: c1. Determine whether the initial water temperature T0 is greater than the second preset temperature T2, T2 = 90 - P / 5Q, where Q is the actual flow rate of the water pump, in the unit of g / s, and P is the power of the heating module, in the unit of W; c2. If T0>T2, start the water pump to run continuously, and drive the nozzle to reciprocate and spray hot water towards the blades by the stepper motor until all the water in the water tank is used up, and set the temperature when the water temperature in the steam generator is stable as T3; c3. If T0≤T2, run the heating module, the water pump runs continuously, and drive the nozzle to reciprocate and spray hot water towards the blades by the stepper motor until all the water in the water tank is used up, and set the temperature when the water temperature in the steam generator is stable as T3.

8. The method for cleaning a fan according to claim 7, characterized in that, In step c2 or c3, in the step that the water pump runs continuously until all the water in the water tank is used up, it further includes the steps: c41. Continuously run the water pump to inject water into the steam generator; c42, determine whether the temperature T inside the steam generator detected by the temperature sensor X is greater than the third preset temperature T4, where T1 ≥ T4 ≥ T3 + 10°C; If so, determine that all the water in the water tank is used up, and the water pump, the heating module, and the stepper motor stop running synchronously, and the hot water stage ends; If not, loop to execute step c41 and step c42.

9. The method for cleaning a fan according to claim 1, characterized in that, Between step b and step c, it further includes: Step e: Static stage, set the operation time of the static stage as t5, Stop running the water pump and the heating module; Drive the nozzle to move to the initial cleaning position by the stepper motor and then stop; Drive the impeller to continuously run at the first rotational speed within the time t5 by the main motor; t5 is 60 seconds - 180 seconds.

10. The method for cleaning a fan according to claim 1, characterized in that, In step d2, the second rotational speed N2 satisfies: 600 r / min ≤ N2 ≤ 1100 r / min.

11. The fan cleaning method according to claim 10, wherein, In step d2, it includes: The main motor runs for a duration of not less than 180 seconds.

12. The method for cleaning a fan according to claim 1, wherein The time T for the nozzle to reciprocate once along the axial direction of the impeller satisfies: 60 s ≤ T ≤ 120 s.

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