Range hood, range hood parameter detection method, fan adjustment method

Abstract

The present invention relates to a range hood, comprising a casing and a fan arranged in the casing, wherein an oil fume parameter detector is arranged in the casing, and the oil fume parameter detector comprises an optical signal sensor and a vortex generator that causes the oil fume to generate a Karman vortex street phenomenon, and the optical signal sensor is located downstream of the vortex generator in the airflow direction. The range hood can simultaneously detect the oil fume concentration and the airflow velocity without an additional flow sensor. The present invention also relates to an oil fume parameter detection method that can realize accurate calculation of the oil fume concentration and the airflow velocity. The present invention also relates to a fan adjustment method that can accurately adjust the fan speed so that the airflow velocity matches the oil fume concentration more closely.

Description

Technical Field

[0001] The invention relates to a range hood, also relates to a method for detecting oil fume parameters of the range hood, and further relates to a fan adjustment method. Background Art

[0002] Range hoods are essential appliances for people to absorb oil fumes during daily cooking. Products with smoke and stove linkage or intelligent start-up and air volume adjustment functions have become increasingly popular in recent years. On the one hand, some set products with smoke and stove linkage often start the range hood only based on the opening of the stove, and cannot effectively identify the actual changes in oil fume. The detection of oil fume concentration requires additional oil fume concentration sensors for detection. Products with oil fume detection function often use light sensors to detect oil fume concentration, that is, simply use the principle of oil fume affecting the refractive index of light in the air to judge the size of oil fume, and then control the fan speed according to the oil fume concentration, and the response speed is slow. However, in actual use, the oil fume situation changes in a complex manner. During the operation of the range hood, it is impossible to know the real-time correlation between the airflow speed and the oil fume concentration, which can easily cause poor oil fume extraction effect or excessive fan noise. In this case, an additional flow sensor is required to determine whether the current oil fume concentration matches the airflow speed, which is costly and has a low degree of intelligence. Summary of the invention

[0003] The first technical problem to be solved by the present invention is to provide a range hood that can simultaneously detect oil fume concentration and airflow velocity without the need for an additional flow sensor in view of the above-mentioned prior art.

[0004] The second technical problem to be solved by the present invention is to provide a method for detecting oil fume parameters that can accurately calculate oil fume concentration and airflow velocity in response to the above-mentioned prior art.

[0005] The third technical problem to be solved by the present invention is to provide a fan adjustment method for the above-mentioned prior art, which can accurately adjust the fan speed so that the air flow speed and the oil fume concentration are more matched.

[0006] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a range hood, comprising a casing and a fan arranged in the casing, characterized in that: an oil fume parameter detector is arranged in the casing, the oil fume parameter detector comprises an optical signal sensor and a vortex generator that causes the oil fume to produce a Karman vortex street phenomenon, and the optical signal sensor is located downstream of the vortex generator in the airflow direction.

[0007] In order to facilitate the detection of the oil smoke signal corresponding to the oil smoke scattered light, the optical signal sensor includes a light emitter and a first light receiver. The light emitter and the first light receiver are located on both sides of the vortex generator and the first light receiver is located downstream of the light emitter in the airflow direction. The light emitter is arranged facing the vortex area downstream in the airflow direction of the vortex generator.

[0008] In order to simultaneously detect the oil smoke signal corresponding to the light transmitted from the oil smoke, the optical signal sensor also includes a second optical receiver, which is arranged upstream in the airflow direction on the same side of the first optical receiver, and the second optical receiver faces the light emitter in a direction perpendicular to the airflow direction.

[0009] In order to ensure the consistency of the flow direction of the oil smoke before it passes through the vortex generator, and thus to obtain more accurate oil smoke signals and airflow velocity, the oil smoke parameter detector also includes a rectifying module for rectifying the flow direction of the oil smoke, and the rectifying module is arranged upstream of the airflow direction of the vortex generator.

[0010] Preferably, the rectifier module comprises a base body, and a plurality of channels extending along the airflow direction are provided in the base body.

[0011] Preferably, the vortex generator is a cylinder.

[0012] Preferably, the oil smoke parameter detector is arranged on the inner wall of the casing facing the lower part of the air inlet of the fan.

[0013] The technical solution adopted by the present invention to solve the second technical problem is: a method for detecting oil fume parameters of a range hood, characterized in that: the range hood is the range hood as described above;

[0014] The first light receiver in the optical signal sensor detects the light signal scattered by the oil smoke, obtains the oil smoke signal value downstream of the airflow direction of the vortex generator according to the sampling period, and averages the oil smoke signal values ​​Pi collected within a set time, thereby obtaining the oil smoke signal value P;

[0015] The signal value Pi collected within the set time is processed by Fourier transform to obtain the main frequency f of the oil smoke passing through the vortex generator, and the air flow velocity v is calculated according to the formula f=Sr(v / d), where Sr is the Strouhal number and d is the diameter of the vortex generator.

[0016] In order to reduce the amount of calculation, P is compared with the set minimum threshold Pa. If P≤Pa, it is judged that there is no obvious oil smoke or water vapor, and the airflow velocity is not calculated; if P>Pa, the airflow velocity is calculated.

[0017] The technical solution adopted by the present invention to solve the second technical problem is: a method for detecting oil fume parameters of a range hood, characterized in that: the range hood is the range hood as described above;

[0018] The first light receiver in the optical signal sensor detects the light signal scattered by the oil smoke, obtains the oil smoke signal value P1i downstream of the airflow direction of the vortex generator according to the sampling period, and averages the oil smoke signal values ​​P1i collected within a set time to obtain an average value P1;

[0019] The second optical receiver in the optical signal sensor detects the optical signal transmitted from the oil smoke, obtains the oil smoke signal value P2i according to the sampling period, and averages the oil smoke signal values ​​P1i collected within a set time to obtain an average value P2;

[0020] P1 is compared with the set maximum threshold value Px. If P1≤Px, the oil smoke signal value P=P1, and the signal value P1i collected within the set time is Fourier transformed to obtain the main frequency f of the oil smoke passing through the vortex generator, and the air flow velocity v is calculated according to the formula f=Sr(v / d), where Sr is the Strouhal number and d is the diameter of the vortex generator; if P1>Px, the oil smoke signal value P=P2, and the signal value P2i collected within the set time is Fourier transformed to obtain the main frequency f of the oil smoke passing through the vortex generator, and the air flow velocity v is calculated according to the formula f=Sr(v / d).

[0021] In order to reduce the amount of calculation, if P1≤Pa, it is judged that there is no obvious oil smoke or water vapor, and the air flow velocity is not calculated.

[0022] Preferably, the oil smoke concentration value is determined according to the oil smoke signal value P.

[0023] The technical solution adopted by the present invention to solve the third technical problem is: a fan adjustment method for a range hood, characterized in that: based on the above-mentioned oil fume parameter detection method, an oil fume signal value and an airflow velocity are obtained;

[0024] Initializing different oil smoke concentration levels, initializing the oil smoke signal thresholds corresponding to the different oil smoke concentration levels for the first optical receiver, and initializing the air flow velocity thresholds matching the different oil smoke concentration levels;

[0025] The oil fume signal value P is compared with the threshold values ​​of each oil fume concentration level to determine the oil fume concentration level Y of the current oil fume concentration in the range hood, and the calculated air flow velocity v is compared with the air flow velocity threshold value corresponding to the oil fume concentration level Y, and the fan speed is adjusted according to the comparison result to make the air flow velocity match the oil fume signal value.

[0026] In order to make the fan adjustment amount adapt to the corresponding oil fume concentration level and avoid the fan speed adjustment being too fast or too slow, the unit fan speed adjustment amount corresponding to different oil fume concentration levels is initialized;

[0027] When the fan speed needs to be adjusted, the fan speed is adjusted according to the unit fan speed adjustment amount corresponding to the oil fume concentration level Y.

[0028] The technical solution adopted by the present invention to solve the third technical problem is: a fan adjustment method for a range hood, characterized in that: based on the above-mentioned oil fume parameter detection method, the oil fume concentration and airflow velocity are obtained;

[0029] Initializing different oil smoke concentration levels, initializing oil smoke signal thresholds corresponding to different oil smoke concentration levels for the first optical receiver, and initializing oil smoke signal thresholds corresponding to different oil smoke concentration levels for the second optical receiver;

[0030] Initialize the airflow velocity thresholds matching different oil smoke concentration levels;

[0031] The oil smoke signal value P is compared with the oil smoke concentration level threshold corresponding to the corresponding light receiver, and then the oil smoke concentration level Y of the current oil smoke concentration in the range hood is determined, and the calculated air flow velocity v is compared with the air flow velocity threshold corresponding to the oil smoke concentration level Y, and then the fan speed is adjusted according to the comparison result so that the air flow velocity matches the oil smoke signal value.

[0032] In order to make the fan adjustment amount adapt to the corresponding oil fume concentration level and avoid the fan speed adjustment being too fast or too slow, the unit fan speed adjustment amount corresponding to different oil fume concentration levels is initialized;

[0033] When the fan speed needs to be adjusted, the fan speed is adjusted according to the unit fan speed adjustment amount corresponding to the oil fume concentration level Y.

[0034] Compared with the prior art, the advantages of the present invention are: the range hood of the present invention, by setting a vortex generator, actively induces the oil smoke to generate the Karman vortex street phenomenon, and the mixed fluid of the oil smoke and the airflow is easier to separate in the vortex area of ​​the vortex generator, and the scattering effect of the separated oil smoke on light is stronger than the scattering effect of the normally flowing oil smoke on light, so it is easier to detect the follower of oil smoke and other air medium flowing in the area with shedding vortex, and the vortex can be used to enhance the detection effect of light changes, and improve the timeliness and accuracy of oil smoke concentration detection. And based on the relationship that the frequency of a single vortex in the Karman vortex street is proportional to the airflow velocity, the airflow velocity is calculated, and then the matching situation of the oil smoke concentration and the airflow velocity is judged without an additional flow detection module, and then the fan speed is adjusted, so as to achieve real-time dynamic and high-precision adjustment and control of the range hood.

[0035] The oil fume parameter detection method and the fan adjustment method of the range hood of the present invention provide specific calculation and adjustment methods, which are simple to calculate and convenient to adjust. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 1 is a diagram showing the internal structure of a range hood in an embodiment of the present invention.

[0037] Figure 2 This is a structural diagram of the oil smoke parameter detector in Example 1 of the present invention.

[0038] Figure 3 This is a state diagram of oil smoke passing through the oil smoke parameter detector in the first embodiment of the present invention.

[0039] Figure 4 This is a structural diagram of the oil smoke parameter detector in the second embodiment of the present invention.

[0040] Figure 5 This is a state diagram of oil smoke passing through the oil smoke parameter detector in the second embodiment of the present invention. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below with reference to the accompanying drawings.

[0042] Embodiment 1

[0043] like Figure 1 and Figure 2 As shown, the range hood in this embodiment includes a housing 1 and a fan 2 disposed in the housing 1. A fume parameter detector 3 is disposed in the housing 1, and the fume parameter detector 3 can be used to detect fume concentration and airflow velocity. The fume parameter detector 3 in this embodiment is disposed on the inner wall of the housing 1 facing the lower part of the air inlet of the fan 2. The fume sucked by the range hood must pass through this position, so arranging the fume parameter detector 3 at this position can achieve more accurate data detection.

[0044] The oil fume parameter detector 3 includes an optical signal sensor 31, a vortex generator 32, and a rectifier module 33. The vortex generator 32 is used to make the oil fume passing through its setting position generate a Karman vortex street phenomenon. The vortex generator 32 in this embodiment is a cylinder. The optical signal sensor 31 and the vortex generator 32 that makes the oil fume, the optical signal sensor 31 is located downstream of the airflow direction of the vortex generator 32, and the rectifier module 33 is set upstream of the airflow direction of the vortex generator 32. The rectifier module 33 is used to rectify the flow direction of the oil fume, so that the oil fume and airflow directions passing through the vortex generator 32 at any time remain consistent. The rectifier module 33 in this embodiment includes a base body, and a plurality of channels extending along the airflow direction are opened in the base body. The airflow and oil fume in the range hood flow from bottom to top, the channels in the rectifier module 33 are set vertically, the rectifier module 33 is set below the vortex generator 32, and the optical signal sensor 31 is set above the vortex sensor.

[0045] The optical signal sensor 31 in this embodiment includes a light emitter 311 and a first light receiver 312. The light emitter 311 and the first light receiver 312 are located on both sides of the vortex generator 32, and the first light receiver 312 is located downstream of the light emitter 311 in the airflow direction. The light emitter 311 is arranged facing the vortex area downstream of the vortex generator 32 in the airflow direction.

[0046] When the range hood is working, the mixed fluid of oil smoke and airflow passing through the rectifying module 33 bypasses the vortex generator 32, and double-row line vortices with opposite rotation directions and regular arrangement will appear on both sides of the downstream of the vortex generator 32, forming a Karman vortex street. The mixed fluid of oil smoke and airflow is easier to separate in the vortex area of ​​the vortex generator 32, and the scattering effect of the separated oil smoke on light is stronger than that of the normally flowing oil smoke on light. Therefore, it is easier to detect the follower of oil smoke and other air medium flowing in the area with shedding vortexes, and the vortex can be used to enhance the detection effect of light changes, thereby improving the timeliness and accuracy of oil smoke concentration detection. And based on the relationship that the frequency of a single vortex in the Karman vortex street is proportional to the airflow velocity, the airflow velocity is calculated, and then the matching of oil smoke concentration and airflow velocity is judged without an additional flow detection module, and then the speed adjustment of the fan 2 is realized, achieving real-time dynamic and high-precision adjustment and control of the range hood.

[0047] Based on this principle, the method for detecting oil fume parameters of the aforementioned range hood is as follows.

[0048] During the operation of the range hood, the first light receiver 312 in the light signal sensor 31 detects the light signal based on the scattering of the oil smoke. The greater the oil smoke concentration, the higher the light intensity based on the heat dissipation of the oil smoke, and the stronger the oil smoke signal detected by the corresponding first light receiver 312. Based on the relationship between the oil smoke signal value detected by the first tube receiver and the oil smoke concentration, the oil smoke concentration value is calculated and determined according to the oil smoke signal value detected by the first tube receiver. The relationship between the oil smoke signal value detected by the first tube receiver and the oil smoke concentration can be obtained through experiments.

[0049] Specifically, the first optical receiver 312 detects and obtains the oil smoke signal value Pi based on the light scattering effect of the oil smoke in the downstream of the vortex generator 32 according to the sampling period, and then averages the oil smoke signal value Pi collected within the set time length to obtain the oil smoke signal value P. According to the relationship between the oil smoke signal value and the oil smoke concentration, the oil smoke concentration value corresponding to the oil smoke signal value P can be calculated. The set time length is determined according to the specific adjustment accuracy requirements and the sampling frequency of the first optical receiver 312.

[0050] The signal value Pi collected within the set time is processed by Fourier transform to obtain the main frequency f of the oil smoke passing through the vortex generator 32, and the air flow velocity v is calculated according to the formula f=Sr(v / d), where Sr is the Strouhal number and d is the diameter of the vortex generator 32.

[0051] For range hoods, when the air inlet area remains unchanged, the air volume is proportional to the airflow speed. For range hood testing, there are usually reference data such as a comparison table of the matching relationship between oil fume concentration and airflow speed. Based on the reference data, the optimal airflow speed range for matching different oil fume concentrations can be understood. Based on these reference data, it can be determined whether the current oil fume signal value P matches the airflow speed v. If they match, the speed of fan 2 is maintained, and if they do not match, the speed of fan 2 is adjusted.

[0052] Specifically, P is compared with a set minimum threshold value Pa. If P≤Pa, it is determined that there is no obvious oil smoke or water vapor, and the airflow velocity is not calculated, which can reduce the amount of calculation; if P>Pa, the airflow velocity is calculated.

[0053] The adjustment method of the fan 2 of the aforementioned range hood is to initialize different oil fume concentration levels, initialize the oil fume signal thresholds corresponding to different oil fume concentration levels for the first light receiver 312, and initialize the airflow velocity thresholds matching different oil fume concentration levels. The number of oil fume concentration levels is specifically set according to the needs. In this embodiment, the oil fume concentration levels are divided into low oil fume concentration levels, medium oil fume concentration levels, and high oil fume concentration levels. For these three levels of oil fume concentration, two oil fume concentration thresholds can be set to distinguish them. In this embodiment, the oil fume signal threshold used to distinguish low oil fume concentration levels and medium oil fume concentration levels is Pb, and the oil fume signal threshold used to distinguish medium oil fume concentration levels and high oil fume concentration levels is Pc, Pc>Pb. To achieve a good oil fume suction effect without causing unnecessary noise, the corresponding airflow velocity ranges corresponding to low oil fume concentration levels, medium oil fume concentration levels, and high oil fume concentration levels are also different, and the number of airflow velocity ranges is consistent with the number of oil fume concentration levels. In this way, two airflow velocity thresholds are set for each airflow velocity range. The higher the oil fume concentration, the greater the corresponding airflow velocity needs to be. In this embodiment, the air flow velocity thresholds for distinguishing three air flow velocity ranges are Va and Vb, respectively, and Va<Vb.

[0054] The oil smoke signal value P and the air flow velocity v are obtained based on the above-mentioned oil smoke parameter detection method.

[0055] The oil fume signal value P is compared with the threshold values ​​of each oil fume concentration level to determine the oil fume concentration level Y at which the current oil fume concentration in the range hood is located. The calculated air flow velocity v is compared with the air flow velocity threshold value corresponding to the oil fume concentration level Y, and the speed of the fan 2 is adjusted according to the comparison result so that the air flow velocity matches the oil fume signal value.

[0056] Specifically, if P<Pb, the current oil smoke situation is judged to be at a low oil smoke concentration level, and the polarity of v is compared with Va. If v<Va, the current speed of fan 2 is maintained. If v≥Va, the speed of fan 2 is controlled to be reduced so that the airflow speed generated by fan 2 matches the oil smoke concentration.

[0057] If Pb≤P≤Pc, it is judged that the current oil fume situation is at the medium oil fume concentration level. At this time, v is compared with Va and Vb respectively. If Va≤v≤Vb, the current speed of fan 2 is maintained. If v<Va, the speed of fan 2 is controlled to increase. If v>Vb, the speed of fan 2 is controlled to decrease, so that the corresponding airflow velocity generated by fan 2 matches the oil fume concentration.

[0058] If P>Pc, it is judged that the current oil smoke situation is at a high oil smoke concentration level. At this time, v is compared with Vb. If v>Vb, the current speed of fan 2 is adjusted. If v≤Vb, the speed of fan 2 is controlled to increase.

[0059] In order to avoid the situation where the speed adjustment amount of fan 2 is too large or too small to match the current oil fume concentration during the speed adjustment of fan 2, the oil fume suction effect can be quickly improved after the speed adjustment of fan 2. In this embodiment, the unit speed adjustment amount of fan 2 corresponding to different oil fume concentration levels is initialized. The smaller the oil fume concentration level, the smaller the corresponding unit speed adjustment amount of fan 2. When the speed of fan 2 needs to be adjusted, the speed of fan 2 is adjusted according to the unit speed adjustment amount of fan 2 corresponding to the oil fume concentration level Y.

[0060] A control circuit board is usually provided in the range hood, and the fan 2 and the oil fume parameter detector 3 are both electrically connected to the control circuit board, so that the signal collected by the oil fume parameter detector 3 can be transmitted to the control circuit board, and the control circuit board obtains the aforementioned oil fume concentration and airflow velocity through calculation, and then the rotation speed of the fan 2 is controlled based on the aforementioned method.

[0061] Embodiment 2

[0062] The difference between this embodiment and the first embodiment is that the optical signal sensor 31 also includes a second optical receiver 313, which is arranged upstream in the airflow direction on the same side of the first optical receiver 312, and faces the optical transmitter 311 in a direction perpendicular to the airflow direction. In this way, the second optical receiver 313 can receive the light signal transmitted from the oil smoke, and then obtain the corresponding oil smoke signal value. Since the larger the oil smoke, the less light is transmitted, the size of the oil smoke signal value detected by the second optical receiver 313 is inversely proportional to the actual oil smoke concentration value. The detection data of the second optical receiver 313 is used to avoid that when the oil smoke concentration is too high, the oil smoke concentration signal value detected by the first optical receiver 312 cannot follow the oil smoke changes well, and cannot more accurately detect the oil smoke concentration. At this time, the oil smoke concentration value can be calculated by the oil smoke signal value detected by the second optical receiver 313, so that the calculated oil smoke concentration data is more accurate.

[0063] The method for detecting the oil fume parameters of the corresponding range hood is as follows.

[0064] During the operation of the range hood, the first light receiver 312 in the optical signal sensor 31 detects the light signal based on oil smoke scattering, obtains the oil smoke signal value P1i downstream of the airflow direction of the vortex generator 32 according to the sampling period, and averages the oil smoke signal values ​​P1i collected within the set time to obtain the average value P1.

[0065] The second light receiver 313 in the light signal sensor 31 detects the light signal transmitted from the oil smoke, obtains the oil smoke signal value P2i according to the sampling period, and averages the oil smoke signal values ​​P1i collected within a set time to obtain the average value P2.

[0066] P1 is compared with the set maximum threshold value Px. If P1≤Px, the oil smoke signal value P=P1.

[0067] If P1≤Pa, it is determined that there is no obvious oil smoke or water vapor, and the airflow velocity is not calculated. If P1>Pa, the signal value P1i collected within the set time is Fourier transformed, and the main frequency f of the oil smoke passing through the vortex generator 32 is obtained, and the airflow velocity v is calculated according to the formula f=Sr(v / d), where Sr is the Strouhal number and d is the diameter of the vortex generator 32; if P1>Px, the oil smoke signal value P=P2, and the signal value P2i collected within the set time is Fourier transformed, and the main frequency f of the oil smoke passing through the vortex generator 32 is obtained, and the airflow velocity v is calculated according to the formula f=Sr(v / d).

[0068] Accordingly, the oil fume parameter detection method is as follows: initialize different oil fume concentration levels, initialize the oil fume signal thresholds corresponding to different oil fume concentration levels for the first optical receiver 312, and initialize the oil fume signal thresholds corresponding to different oil fume concentration levels for the second optical receiver 313. Initialize the oil fume signal thresholds corresponding to different oil fume concentration levels for the first optical receiver 312 as in Example 1. And the second optical receiver 313 initializes the oil fume signal thresholds corresponding to different oil fume concentration levels. In this implementation, the oil fume signal threshold for distinguishing low oil fume concentration levels and medium oil fume concentration levels is Pe, and the oil fume signal threshold for distinguishing medium oil fume concentration levels and high oil fume concentration levels is Pf, where Pe>Pf.

[0069] Initialize the airflow velocity thresholds matching different oil smoke concentration levels, and the initialization content is the same as that in the first embodiment.

[0070] Based on the above-mentioned oil fume parameter detection method, the oil fume concentration P and the airflow velocity v are obtained. The adjustment method of the fan 2 of the range hood in this embodiment is also the same as that in the first embodiment.

[0071] In the specification and claims of the present invention, terms indicating directions, such as "front", "rear", "up", "down", "left", "right", "side", "top", "bottom", etc., are used to describe various exemplary structural parts and elements of the present invention, but these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only used as explanations 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.

Claims

1. A method for detecting oil fume parameters of a range hood, the range hood comprising a housing (1) and a fan (2) arranged in the housing (1), characterized in that: An oil fume parameter detector (3) is arranged in the casing (1), the oil fume parameter detector (3) comprising an optical signal sensor (31) and a vortex generator (32) for causing the oil fume to generate a Karman vortex street phenomenon, the optical signal sensor (31) being located downstream of the vortex generator (32) in the airflow direction; The optical signal sensor (31) comprises a light emitter (311) and a first light receiver (312), wherein the light emitter (311) and the first light receiver (312) are located on both sides of the vortex generator (32), and the first light receiver (312) is located downstream of the light emitter (311) in the airflow direction, and the light emitter (311) is arranged facing the vortex zone downstream of the vortex generator (32) in the airflow direction; The oil fume parameter detection method of the range hood includes method one or method two; Method 1: The first light receiver (312) in the light signal sensor (31) detects the light signal based on oil smoke scattering, obtains the oil smoke signal value downstream of the vortex generator (32) in the airflow direction according to the sampling period, and averages the oil smoke signal values ​​Pi collected within a set time period to obtain the oil smoke signal value P; Performing Fourier transform processing on the signal value Pi collected within a set time length, thereby obtaining the main frequency f of the oil smoke passing through the vortex generator (32), and calculating the air flow velocity v according to the formula f=Sr(v / d), where Sr is the Strouhal number and d is the diameter of the vortex generator (32); Method 2: The optical signal sensor (31) further comprises a second optical receiver (313), wherein the second optical receiver (313) is arranged upstream in the airflow direction on the same side as the first optical receiver (312), and the second optical receiver (313) faces the optical transmitter (311) in a direction perpendicular to the airflow direction; The first light receiver (312) in the light signal sensor (31) detects the light signal based on the scattering of the oil smoke, obtains the oil smoke signal value P1i downstream of the airflow direction of the vortex generator (32) according to the sampling period, and averages the oil smoke signal values ​​P1i collected within a set time period to obtain an average value P1; The second light receiver (313) in the light signal sensor (31) detects the light signal transmitted from the oil smoke, obtains the oil smoke signal value P2i according to the sampling period, and averages the oil smoke signal values ​​P1i collected within a set time period to obtain an average value P2; P1 is compared with a set maximum threshold value Px. If P1≤Px, the oil smoke signal value P=P1, and the signal value P1i collected within the set time period is Fourier transformed to obtain the main frequency f of the oil smoke passing through the vortex generator (32), and the air flow velocity v is calculated according to the formula f=Sr(v / d), where Sr is the Strouhal number and d is the diameter of the vortex generator (32). If P1>Px, the oil smoke signal value P=P2, and the signal value P2i collected within the set time period is Fourier transformed to obtain the main frequency f of the oil smoke passing through the vortex generator (32), and the air flow velocity v is calculated according to the formula f=Sr(v / d).

2. The method for detecting oil smoke parameters according to claim 1, characterized in that: In method 1, P is compared with a set minimum threshold Pa. If P≤Pa, it is determined that there is no obvious oil smoke or water vapor, and the airflow velocity is not calculated; if P>Pa, the airflow velocity is calculated.

3. The method for detecting oil smoke parameters according to claim 1, characterized in that: In method 2, if P1≤Pa, it is judged that there is no obvious oil smoke or water vapor, and the air flow velocity is not calculated.

4. The method for detecting oil smoke parameters according to any one of claims 1 to 3, characterized in that: The oil smoke concentration value is determined according to the oil smoke signal value P.

5. A method for adjusting a fan of a range hood, characterized in that: Acquire the oil smoke signal value and air flow velocity based on the oil smoke parameter detection method as described in method 1 of claim 1 or 2; Initializing different oil smoke concentration levels, initializing oil smoke signal thresholds corresponding to different oil smoke concentration levels for the first optical receiver (312), and initializing air flow velocity thresholds matching different oil smoke concentration levels; The oil fume signal value P is compared with each oil fume concentration level threshold, and then the oil fume concentration level Y at which the current oil fume concentration in the range hood is located is determined; the calculated air flow speed v is compared with the air flow speed threshold corresponding to the oil fume concentration level Y, and then the speed of the fan (2) is adjusted according to the comparison result so that the air flow speed matches the oil fume signal value.

6. The range hood fan adjustment method according to claim 5, characterized in that: Initialize the speed adjustment amount of the unit fan (2) corresponding to different oil smoke concentration levels; When it is necessary to adjust the speed of the fan (2), the speed of the fan (2) is adjusted according to the unit speed adjustment amount of the fan (2) corresponding to the oil smoke concentration level Y.

7. A method for adjusting a fan of a range hood, characterized in that: Obtaining the oil fume concentration and airflow velocity based on the oil fume parameter detection method as described in method 2 of claim 1 or 3; Initializing different oil smoke concentration levels, initializing oil smoke signal thresholds corresponding to different oil smoke concentration levels for the first optical receiver (312), and initializing oil smoke signal thresholds corresponding to different oil smoke concentration levels for the second optical receiver (313); Initialize the airflow velocity thresholds matching different oil smoke concentration levels; The oil fume signal value P is compared with the oil fume concentration level threshold value corresponding to the corresponding light receiver, thereby determining the oil fume concentration level Y at which the current oil fume concentration in the range hood is located, and the calculated air flow speed v is compared with the air flow speed threshold value corresponding to the oil fume concentration level Y, thereby adjusting the speed of the fan (2) according to the comparison result so that the air flow speed matches the oil fume signal value.

8. The method for adjusting the fan of a range hood according to claim 7, characterized in that: Initialize the speed adjustment amount of the unit fan (2) corresponding to different oil smoke concentration levels; When it is necessary to adjust the speed of the fan (2), the speed of the fan (2) is adjusted according to the unit speed adjustment amount of the fan (2) corresponding to the oil smoke concentration level Y.

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