Self-cleaning control method for range hood

Abstract

The present invention discloses a self-cleaning control method for a range hood, wherein the range hood comprises an air inlet for sucking in oil smoke and a fan system, the air inlet and the fan system are fluidically connected, the fan system comprises an impeller capable of forward and reverse rotation, and the range hood further comprises a smoke guide plate capable of opening and closing the air inlet; the control method comprises the following steps: 1) the range hood is turned on, the fan system is running, and the smoke guide plate opens the air inlet; 2) the range hood is turned off, and the smoke guide plate closes the air inlet; 3) the oil-stripping program is manually started, and the process proceeds to step 4); or, whether the oil-stripping program is entered is automatically determined, and when it is automatically determined that the oil-stripping program needs to be entered, the process proceeds to step 4); 4) the oil-stripping program is entered, and the impeller is reversed to perform oil-stripping; 5) after the oil-stripping program is completed, the range hood enters a standby or shutdown state.

Description

Technical Field

[0001] The invention relates to an oil fume purification device, in particular to a self-cleaning control method of a range hood. Background Art

[0002] Range hoods have become an indispensable kitchen appliance in modern homes. They operate based on the principles of fluid dynamics, using a centrifugal fan installed inside the hood to draw in and exhaust cooking fumes, while a filter removes some grease particles. A centrifugal fan consists of a volute, an impeller mounted within the volute, and a motor that drives the impeller. As the impeller rotates, negative pressure is generated at the fan's center, drawing cooking fumes from beneath the hood into the fan. After being accelerated by the fan, the volute collects them and guides them out of the room.

[0003] After a range hood has been operating for extended periods, oil and dirt will inevitably accumulate on the components it passes through, particularly the fan's volute and impeller. This accumulation of oil and dirt can lead to reduced efficiency. To address this impeller contamination issue, various self-cleaning technologies have been developed, one of which is high-speed oil removal. However, most oil removal technologies use forward rotation, resulting in poor oil removal performance.

[0004] For this purpose, some reverse oil-stripping technologies have been proposed, and their oil-stripping effects and noise indicators are better than those of forward rotation technologies. For example, a self-cleaning method for an oil fume extraction device disclosed in a Chinese patent application number 201811651312.3 includes a centrifugal fan, a control device, and a switch. The centrifugal fan includes a volute and a centrifugal impeller. The centrifugal impeller includes a base, a front annular plate, and arc-shaped blades. The gap between the radial outer side of the centrifugal impeller and the circumferential wall of the volute gradually increases clockwise from the air outlet end. When working, the switch is operated and the control device rotates the centrifugal fan. When closed, the switch is operated and the control device delays the operation of the centrifugal fan. The centrifugal impeller rotates in the direction of work and then reverses to remove oil. It rotates forward during work, and after use, it delays forward rotation and then reverses. The forward rotation fully discharges the residual smoke and cleans the attached oil. The reverse rotation removes the attached oil and achieves self-cleaning.

[0005] In the application of oil-swing technology, most of them are similar to those disclosed in the above-mentioned prior art. During self-cleaning, the impeller is simply controlled to reverse and spin the oil, and the oil-swing time and speed are fixed. It is difficult to introduce an oil-swing method that is more in line with the user's own usage according to the user's actual usage, so it is difficult to achieve the expected self-cleaning effect. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to provide a self-cleaning control method for a range hood in view of the deficiencies in the above-mentioned prior art, thereby reducing the adhesion of oil stains and improving the oil removal effect.

[0007] The second technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and provide a self-cleaning control method for a range hood, thereby improving the oil-stripping effect and user experience by matching the oil-stripping time and oil-stripping speed with the user's usage conditions.

[0008] The present invention solves the first technical problem by adopting a technical solution: a self-cleaning control method for a range hood, wherein the range hood includes an air inlet for sucking in oil smoke and a fan system, the air inlet and the fan system being in fluid communication, the fan system including an impeller capable of forward and reverse rotation, and the range hood further including a smoke guide plate capable of opening and closing the air inlet; the control method is characterized in that:

[0009] 1) The range hood is turned on, the fan system is running, and the smoke guide plate opens the air inlet;

[0010] 2) The range hood is turned off, and the smoke guide plate closes the air inlet;

[0011] 3) Manually start the oil-stripping program and proceed to step 4); or automatically determine whether to enter the oil-stripping program. When it is automatically determined that the oil-stripping program needs to be entered, proceed to step 4);

[0012] 4) Entering the oil-swing program, the impeller reverses to perform oil-swing;

[0013] 5) After the oil-stripping process is completed, the range hood enters the standby or shutdown state.

[0014] During the above-mentioned oil-shaking process, since the smoke guide plate is in a state of closing the air inlet, the air inside the range hood can only go out but not come in, and a negative pressure can be formed inside. After the negative pressure is formed, the pressure on the oil and the oil and the oil on the impeller is reduced, and the mutual adhesion is reduced. When the mutual adhesion is reduced, the oil stains on the impeller are easier to shake off.

[0015] In order to facilitate automatic start of self-cleaning, the range hood further includes a camera. In step 3), automatically determining whether to enter the oil-stripping program includes the following steps:

[0016] 3.1) The camera identifies whether the user is in the kitchen and, when detecting that the user has left the kitchen, records the time when the user left the kitchen as t1;

[0017] 3.2) The camera identifies whether there are ingredients on the kitchen counter that the user has prepared but not yet cooked. If so, proceed to step 3.3); if not, proceed to step 3.4);

[0018] 3.3) When time reaches t2, determine whether the user has not returned to the kitchen. If yes, proceed to step 4); if not, return to step 3.1);

[0019] 3.4) When time reaches t3, determine whether the user has not returned to the kitchen. If yes, proceed to step 4); if not, return to step 3.1); wherein t3 ≥ t2.

[0020] The technical solution adopted by the present invention to solve the second technical problem is as follows: the range hood further includes a smoke sensor for detecting the oil smoke concentration. In step 1), the amount of smoke q passing through per unit time is calculated based on the oil smoke concentration detected by the smoke sensor, and the speed r of the impeller during the operation of the fan system is detected. In step 2), the operating time t of the fan system is recorded. In step 4), the following steps are included:

[0021] 4.1) Calculate the amount of oil accumulated on the impeller during this operation:

[0022] Z=K1×(r×(1-e) r )×K2×(q×(1-f) q )×K3×(t×(1-g) t )

[0023] Among them, K1, K2, K3 are correction coefficients, e, f, g are constants, and the value range of K1, K2, K3, e, f, g is 0~1;

[0024] 4.2) Based on Z obtained in step 4.1), the oil-sweeping time T and the oil-sweeping speed R are obtained. Z is positively correlated with T and R, respectively.

[0025] By calculating the amount of accumulated oil in real time, the appropriate oil-stripping time and speed are determined each time the user uses the range hood, so that the time and speed of each oil-stripping are most suitable for the user's usage conditions, thereby maximizing the oil-stripping effect and user experience.

[0026] Preferably, in step 4.2), the relationship between Z, T and R is:

[0027] When Z≤aZ0, T=t0+n×(Z-Z0) / Z0, R=r0;

[0028] When aZ0<Z≤bZ0, T=mt0, R=r0+p×(Z-aZ0) / Z0;

[0029] When bZ0<Z≤cZ0, T=mt0+n×(Z-bZ0) / Z0, R=R0;

[0030] When Z>cZ0, T=T0, R=R0;

[0031] Among them, a, b, c, m, n, and p are natural number constants, and satisfy a<b<c, m<n, Z0 is the preset oil accumulation amount reference value, t0 is the preset oil rejection time reference value, r0 is the preset oil rejection speed reference value, T0 is the preset maximum value of the oil rejection time, mt0 is not less than t0+n×(Z-Z0) / Z0, and T0 is not less than mt0+n×(Z-bZ0) / Z0.

[0032] The higher the speed during oil swinging, the better the oil swinging effect, and the longer the oil swinging time, the better the oil swinging effect; however, the higher the speed, the greater the noise, and the oil swinging time should not be too short or too long; therefore, when the amount of oil accumulation is relatively small, the required oil swinging speed and oil swinging time are also relatively small, and when the amount of oil accumulation is large, you can choose to increase the speed or increase the time, so the method of increasing the time is recommended; and when the amount of oil accumulation is large, it is recommended to use a method with a relatively large oil swinging speed and oil swinging time.

[0033] Compared with the prior art, the advantages of the present invention are:

[0034] 1. During the oil-spinning process, the smoke guide plate is in a state of closing the air inlet, so that less air enters the range hood and more air exits, forming a negative pressure inside. After the negative pressure is formed, the pressure on the oil and the oil on the impeller is reduced, which also reduces the mutual adhesion. When the mutual adhesion is reduced, the oil stains on the impeller are easier to shake off;

[0035] 2. By setting up a camera to determine whether the user is in the kitchen, it can determine whether to start the oil-spinning self-cleaning process, which can avoid the noise generated by the oil-spinning process from affecting the user;

[0036] 3. By calculating the amount of accumulated oil in real time, the system can determine the appropriate oil-stripping time and speed each time the user uses the range hood, so that the time and speed of each oil-stripping are most suitable for the user's usage conditions, thereby maximizing the oil-stripping effect and user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of a range hood according to an embodiment of the present invention;

[0038] Figure 2 2 is a cross-sectional view of a range hood according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Since the embodiments disclosed in the present invention can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0041] See also Figure 1 and Figure 2 A range hood, which is a top-suction range hood in this embodiment, includes a fume hood 1, a fan frame 2 arranged above the fume hood 1, and a fan system 3 arranged in the fan frame 2. The fan system 3 is preferably a centrifugal fan, including a volute 31, an impeller 32 arranged in the volute 31, and a motor 33 for driving the impeller 32 to rotate.

[0042] An air inlet 11 is formed on the smoke hood 1 and is fluidly connected to the interior of the fan frame 2 (the fan system 3). A smoke deflector 4 is disposed below the air inlet 11. The smoke deflector 4 can be raised and lowered relative to the smoke hood 1 to open and close the air inlet 11. The raiseable smoke deflector 4 utilizes existing technology, as disclosed in the applicant's prior Chinese patent application numbers 201621469629.1 and 201621470491.7, and will not be further described here.

[0043] A smoke sensor 5 is installed in the fan frame 2 at a location corresponding to the fan system 3, such as at the air inlet of the fan system 3, to detect the amount of oil smoke entering the fan system 3. Alternatively, the smoke sensor 5 can be installed on the fume hood 1. A camera 6 is installed on the fume hood 1, such as on the front side of the fume hood 1, to detect the presence of a human body and whether cooking operations are occurring.

[0044] The range hood of the present invention, the control method for performing self-cleaning comprises the following steps:

[0045] 1) The range hood is turned on, the fan system 3 is running, the smoke guide plate 4 is lowered, and the air inlet 11 is opened. If the smoke sensor 5 detects oil smoke, the amount of smoke q passing through per unit time (e.g., 1 minute) is calculated based on the oil smoke concentration detected by the smoke sensor 5. If the smoke sensor 5 does not detect oil smoke, it is determined that the user may be trying out the range hood, and q is 0. At the same time, the speed r of the impeller 32 is detected when the fan system 3 is running. The faster the speed r of the impeller 32, the faster the oil accumulation rate on the impeller 32, but as the speed r increases, the oil accumulation rate gradually slows down. Similarly, the greater the amount of smoke q passing through per unit time, the faster the oil accumulation rate on the impeller 32, but as the smoke amount q increases, the oil accumulation rate gradually slows down.

[0046] 2) The range hood is turned off, the smoke guide plate 4 rises to close the air inlet 11, and the main control module of the range hood can calculate the operating time t of the fan system 3 and enter step 3);

[0047] 3) Manually start the oil-spinning program or automatically determine whether to enter the oil-spinning program. In the present invention, the automatic determination of whether to enter the oil-spinning program specifically includes the following steps:

[0048] 3.1) Camera 6 identifies whether the user is in the kitchen. When it detects that the user has left the kitchen, the main control module of the range hood (not shown in the drawings, this is prior art) records the time when the user left the kitchen as t1;

[0049] 3.2) Camera 6 identifies whether there are ingredients on the kitchen counter that have been prepared by the user but not yet cooked. If so, proceed to step 3.3); if not, proceed to step 3.4);

[0050] 3.3) When time reaches t2, determine whether the user has not returned to the kitchen. If yes, proceed to step 4); if not, return to step 3.1);

[0051] 3.4) When time reaches t3, determine whether the user has not returned to the kitchen. If yes, proceed to step 4); if not, return to step 3.1); where t3 ≥ t2;

[0052] 4) Enter the oil-stripping procedure, which includes the following steps:

[0053] 4.1) Calculate the amount of oil accumulated Z on the impeller 32 during this operation. As mentioned above, the faster the speed r of the impeller 32, the faster the rate of oil accumulation on the impeller 32. However, as the speed r increases, the oil accumulation rate gradually slows down. The greater the amount of smoke passing through per unit time q, the faster the oil accumulation rate on the impeller 32. However, as the amount of smoke q increases, the oil accumulation rate gradually slows down. Furthermore, because the viscosity between new oil and new oil is lower than the viscosity between new oil and the impeller 32, and between new oil and old oil, the rate of increase gradually decreases as more new oil is added to the impeller 32 in a single operation. Based on the above reasons, Z is calculated using the following formula:

[0054] Z=K1×(r×(1-e) r )×K2×(q×(1-f) q )×K3×(t×(1-g) t )

[0055] Among them, the unit of r is r / min, the unit of q is cubic meter, and the unit of t is minute, but only the numerical value is used without the unit in the calculation; K1, K2, and K3 are correction coefficients to correct the effects of r, q, and t on the oil accumulation to the same numerical effect as Z; e, f, and g are constants to simulate the numerical law of how changes in r, q, and t will affect the oil accumulation. The value ranges of K1, K2, K3, e, f, and g are all 0 to 1;

[0056] It should be noted that the Z obtained in this step is only a relative value used to calculate the oil-spinning time T and the oil-spinning speed R, and is not necessarily the true value of the actual increase in the amount of oil stains on the impeller 32 when the range hood is working;

[0057] The above K1, K2, K3, e, f, and g can be obtained through experiments. For example, the preferred experimental conditions are: temperature: room temperature 20°C ± 5°C, experimental environment: experimental environment without obvious external airflow in the laboratory; the experimental steps are: first weigh the impeller 32, then simulate various cooking operations (including cooking type and cooking working time), and operate at a specified working speed (700-1500 r / min, simulating the entire speed range that users will use, 100 r / min as a gear); after completing one experiment, record r, q, and t, and weigh the impeller 32 again to obtain the oil accumulation amount z; substitute sufficient data obtained from multiple experiments into the above formulas, and then calculate the values of K1, K2, K3, e, f, and g;

[0058] 4.2) Based on Z obtained in step 4.1), the oil-spinning time T and the oil-spinning speed R are obtained. The relative relationship between Z, T, and R can be pre-stored in the main control module of the range hood. Z is positively correlated with T and R, respectively. The above relative relationship can be obtained through experiments, such as by dividing Z into segments, with different segments having corresponding T and R (which can be fixed values, value ranges, or the relationship provided in this embodiment as described below);

[0059] Since the higher the speed during oil sweeping, the better the oil sweeping effect, and the longer the oil sweeping time, the better the oil sweeping effect; however, the higher the speed, the greater the noise, and the oil sweeping time should not be too short or too long; therefore, when the amount of oil accumulation is relatively small, the required oil sweeping speed and oil sweeping time are also relatively small, and when the amount of oil accumulation is large, the method of increasing the speed or increasing the time can be selected, so the method of increasing the time is preferred in this embodiment; and when the amount of oil accumulation is large, the method of increasing the oil sweeping speed and oil sweeping time is recommended;

[0060] According to the above logic, the relative relationship between Z, T (minutes), and R (r / min) is:

[0061] When Z≤aZ0, T=t0+n×(Z-Z0) / Z0, R=r0;

[0062] When aZ0<Z≤bZ0, T=mt0, R=r0+p×(Z-aZ0) / Z0;

[0063] When bZ0<Z≤cZ0, T=mt0+n×(Z-bZ0) / Z0, R=R0;

[0064] When Z>cZ o When T=T0, R=R0;

[0065] Wherein, a, b, c, m, n, and p are natural number constants, and a, b, c, m, and n can be selected from 1 to 20 and satisfy a<b<c, m<n. The value range of p is 10 to 1000. For example, in this embodiment, a=3, b=8, c=11, m=3, n=10, and p=100. Z0 is a preset oil accumulation reference value, t0 is a preset oil rejection time reference value, and r0 is a preset oil rejection speed reference value. Preferably, t0=10s, r0=1700r / min, and Z0 is 0.2g; R0 is the highest gear of the fan system 3, such as 2200r / min, and T0 is a preset maximum oil rejection time, such as 1 minute. In addition, mt0 is not less than t0+n×(Z-Z0) / Z0, and T0 is not less than mt0+n×(Z-bZ0) / Z0.

[0066] During the oil-stripping process, since the smoke guide plate 4 is in a state of closing the air inlet 11, less air enters the range hood and more air exits, thereby forming a negative pressure inside. After the negative pressure is formed, the pressure on the oil and the oil on the impeller 32 is reduced, thereby reducing the mutual adhesion between the oil and the oil. With the reduced mutual adhesion, the oil on the impeller 32 is easier to be shaken off.

[0067] 5) After the oil-stripping process is completed, the range hood enters the standby or shutdown state.

[0068] The "fluid communication" referred to in the present invention refers to the spatial position relationship between two components or parts (hereinafter collectively referred to as the first part and the second part), that is, the fluid (gas, liquid or a mixture of the two) can flow from the first part along the flow path or / and be transported to the second part. The first part and the second part can be directly connected, or the first part and the second part can be indirectly connected through at least one third party. The third party can be a fluid channel such as a pipe, channel, conduit, guide member, hole, groove, etc., or it can be a chamber allowing fluid to flow through, or a combination of the above.

Claims

1. A self-cleaning control method for a range hood, the range hood comprising an air inlet (11) for sucking in oil smoke and a fan system (3), the air inlet (11) and the fan system (3) being in fluid communication, the fan system (3) comprising an impeller (32) capable of forward and reverse rotation, the range hood further comprising a smoke guide plate (4) capable of opening and closing the air inlet (11); characterized in that: The control method comprises the following steps: 1) The range hood is turned on, the fan system (3) is running, and the smoke guide plate (4) opens the air inlet (11); 2) The range hood is turned off, and the smoke guide plate (4) closes the air inlet (11); 3) Manually start the oil-stripping program and proceed to step 4); or automatically determine whether to enter the oil-stripping program. When it is automatically determined that the oil-stripping program needs to be entered, proceed to step 4); 4) Entering the oil-swing process, the impeller (32) rotates in reverse to perform oil-swing; 5) After the oil-stripping process is completed, the range hood enters the standby or shutdown state.

2. The range hood self-cleaning control method according to claim 1, characterized in that: The range hood further comprises a camera (6). In step 3), automatically determining whether to enter the oil-stripping program comprises the following steps: 3.1) The camera (6) identifies whether the user is in the kitchen, and when it detects that the user leaves the kitchen, records the time when the user leaves the kitchen as t1; 3.2) The camera (6) identifies whether there are ingredients on the kitchen counter that have been prepared but not yet cooked by the user. If yes, proceed to step 3.3); if not, proceed to step 3.4); 3.3) When time reaches t2, determine whether the user has not returned to the kitchen. If yes, proceed to step 4); if not, return to step 3.1); 3.4) When time reaches t3, determine whether the user has not returned to the kitchen. If yes, proceed to step 4); if not, return to step 3.1); wherein t3 ≥ θ.

3. The range hood self-cleaning control method according to claim 1, characterized in that: The range hood further comprises a smoke sensor (5) for detecting the concentration of oil smoke. In step 1), the amount of smoke q passing through per unit time is calculated based on the oil smoke concentration detected by the smoke sensor (5), and the rotation speed r of the impeller (32) when the fan system (3) is running is detected at the same time. In step 2), the running time t of the fan system (3) is recorded. In step 4), the following steps are included: 4.1) Calculate the amount of oil accumulated Z on the impeller (32) during this operation: Z=K1×(r×(1-e) r )×K2×(q×(1-f)q)×K3×(t×(1-g) t ) Among them, K1, K2, K3 are correction coefficients, e, f, g are constants, and the value range of K1, K2, K3, e, f, g is 0~1; 4.2) Based on Z obtained in step 4.1), the oil-swing time T and the oil-swing speed R are obtained. Z is positively correlated with T and R, respectively.

4. The range hood self-cleaning control method according to claim 3, characterized in that: In step 4.2), the relationship between Z, T and R is: When Z≤aZ0, T=t0+n×(Z-Z0) / Z0, R=r0; When aZ0<Z≤bZ0, T=mt0, R=r0+p×(Z-aZ0) / Z0; When bZ0<Z≤cZ0, T=mt0+n×(Z-bZ0) / z0, R=R0; When Z>cZ0, T=T0, R=R0; Among them, a, b, c, m, n, and p are natural number constants, and satisfy a<b<c, m<n, Z0 is the preset oil accumulation amount reference value, t0 is the preset oil rejection time reference value, r0 is the preset oil rejection speed reference value, T0 is the preset maximum value of the oil rejection time, mt0 is not less than t0+n×(Z-Z0) / Z0, and T0 is not less than mt0+n×(Z-bZ0) / Z0.

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