A method for detecting oil smoke and a range hood

Abstract

The present invention relates to a method for detecting oil smoke, comprising the following steps: obtaining oil smoke concentration data D of an oil smoke detection device in real time; calculating the change data ΔD=D-D0 of the current oil smoke concentration data D relative to the oil smoke concentration data D0 at the last sampling moment; if |ΔD| is greater than the set change threshold ΔD0, ΔD0>0, and the sign of the current change data ΔD relative to the change data calculated last time changes, it is judged that a jump of the oil smoke concentration data occurs; performing weighted calculation of the oil smoke concentration data based on the read oil smoke concentration data D and the jump situation, and then obtaining the oil smoke concentration value Dc. The present invention also relates to a range hood using the method. The oil smoke detection method can perform weighted calculation of the oil smoke concentration based on the size of the oil smoke particles, and then can more scientifically reflect the degree of its harm. The oil smoke concentration detection of the range hood using the method is more scientific and more accurate.

Description

Technical Field

[0001] The invention relates to an oil smoke detection method and also to an oil smoke extractor using the method. Background Art

[0002] Adjusting the fan speed according to the fume concentration is the basic working method of the range hood. Since there is a serious oil pollution problem in fume detection, most of the detection of fume concentration adopts a non-contact optical signal detection scheme. For example, in the Chinese invention patent "Kitchen Device" with the authorization announcement number CN110617535B (application number 201910912619.2), the fume detection component used includes a light emitting device and a light receiving device. The light emitting device is used to emit light to the fume air duct, and the light receiving device is used to receive the light emitted by the light emitting device and output an electrical signal according to the received light. When the concentration of fume particles in the fume air duct changes, it can cause a change in the light intensity received by the light receiving device, thereby realizing the detection of fume concentration. However, this detection scheme will be affected by the size of the fume particles, that is, this scheme has a relatively high detection accuracy for large fume particles with a high water content, but for pure fume particles with a low water content, the detection effect is poor due to the small particle size of the particles. For example, during the oil heating process, the oil fume particles are relatively small. Even if there is a lot of oil fume, the intensity change of the light signal is still very small, but the smell of the oil fume is stronger at this time, and the harm to human health is also greater. Summary of the invention

[0003] The first technical problem to be solved by the present invention is to provide a fume detection method for the above-mentioned prior art, which can perform weighted calculation on the fume concentration based on the size of the fume particles, thereby being able to more scientifically reflect the degree of its hazard.

[0004] The second technical problem to be solved by the present invention is to provide a range hood with more scientific and accurate oil fume concentration detection in view of the above-mentioned prior art.

[0005] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a method for detecting oil smoke, characterized in that: comprising the following steps:

[0006] Real-time acquisition of oil smoke concentration data D of the oil smoke detection device;

[0007] Calculate the change data ΔD=D-D0 of the current oil smoke concentration data D relative to the oil smoke concentration data D0 at the previous sampling time;

[0008] If |ΔD| is greater than the set change threshold ΔD0, ΔD0>0, and the sign of the current change data ΔD changes relative to the last calculated change data, it is determined that a jump in the fume concentration data occurs;

[0009] The oil fume concentration data is weightedly calculated based on the read oil fume concentration data D and the jump condition, and then the oil fume concentration value Dc is obtained.

[0010] As an improvement, the number of jumps within a time range of T from the current moment is accumulated and calculated, where T is a set time threshold, and then the jump number data sum within the range of T is obtained;

[0011] When calculating the oil fume concentration detection value, a weighted calculation is performed on the oil fume concentration data based on the read oil fume concentration data D and the jump number data sum.

[0012] For convenience of calculation, according to the relationship between the preset jump times and the smoke concentration influence amount, the smoke concentration influence amount A corresponding to the current jump times data sum is calculated;

[0013] The oil smoke concentration value Dc=k*D+(1-k)*A is calculated, where k is a weighting coefficient, 0<k≤1, and the larger D is, the larger k is.

[0014] Optionally, a minimum oil fume concentration threshold Dmin and a maximum oil fume concentration threshold Dmax are preset; a first weighted coefficient threshold k1 corresponding to Dmin is preset, and a second weighted coefficient threshold k2 corresponding to Dmax is preset; 0<k1≤k≤k2≤1;

[0015] The oil fume concentration interval [Dmin, Dmax] is divided into a plurality of continuous oil fume concentration intervals, and a corresponding weighting coefficient ki is preset for each oil fume concentration interval;

[0016] When D<Dmin, k=k1;

[0017] When D>Dmax, k=k2;

[0018] When Dmin≤D≤Dmax, the corresponding weighting coefficient ki is determined according to the oil fume concentration interval in which D is located.

[0019] Optionally, a minimum oil fume concentration threshold Dmin and a maximum oil fume concentration threshold Dmax are preset; a first weighted coefficient threshold k1 corresponding to Dmin is preset, and a second weighted coefficient threshold k2 corresponding to Dmax is preset; 0<k1≤k≤k2≤1;

[0020] When D<Dmin, k=k1;

[0021] When D>Dmax, k=k2;

[0022] When Dmin≤D≤Dmax, k=k1+(k2-k1)*(D-Dmin) / (Dmax-Dmin).

[0023] Preferably, the method for acquiring the oil smoke concentration data D is: collecting the detection value DD of the oil smoke detection device in real time, comparing DD with the current reference value B, and if DD<B, updating the reference value B=DD;

[0024] If within the set time period T1, the deviation / standard deviation of each detected value collected relative to the average value of these detected values ​​is less than the preset fluctuation threshold, it is determined that the update reference value is the average value of these detected values.

[0025] D=DD-B.

[0026] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a range hood using the aforementioned oil fume detection method, characterized in that it includes a body with an oil fume passage, an optical signal transmitter and an optical signal receiver arranged in the oil fume passage, and a microprocessor arranged on the body, and the optical signal transmitter and the optical signal receiver are respectively electrically connected to the microprocessor.

[0027] Compared with the prior art, the advantages of the present invention are: the oil fume detection method of the present invention, on the basis of obtaining the oil fume concentration data, determines the particle size of the oil fume by monitoring the jump situation of the data, so as to obtain the oil fume morphology information, and then uses the information to realize the scientific weighted calculation of the oil fume concentration data, thereby reflecting the influence of the oil fume particle size on the oil fume concentration data, and realizing the inspection of the oil fume concentration from two dimensions of the oil fume particle volume concentration and the particle number concentration, thereby obtaining a more accurate oil fume concentration value that can better reflect the nature of the oil fume, so as to deal with the oil fume in a more targeted manner.

[0028] The range hood using this method can detect the oil fume concentration more scientifically and accurately, and the corresponding treatment of the oil fume is more targeted and has a better effect on the oil fume treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Flow chart of the oil smoke detection method in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below with reference to the accompanying drawings.

[0031] like Figure 1As shown, the range hood in this embodiment can be operated by the following oil smoke detection method. The range hood includes a body with an oil smoke passage, an optical signal transmitter and an optical signal receiver arranged in the oil smoke passage, and a microprocessor arranged on the body. The optical signal transmitter and the optical signal receiver are respectively connected to the microprocessor by electrical signals. When working, the microprocessor controls the optical signal transmitter to emit light. When the optical signal receiver receives the light, it transmits the corresponding collected data to the microcontroller. The optical signal transmitter and the optical signal receiver in this embodiment are used as an oil smoke detection device. The optical signal transmitter and the optical signal receiver can be infrared transmitters and infrared receivers.

[0032] As needed, the optical signal transmitter and the optical signal receiver can be arranged in a facing position or in a reflective position. If the optical signal transmitter and the optical signal receiver are arranged in a facing position, the signal strength received by the optical signal receiver is the largest when there is no oil smoke, and the greater the oil smoke concentration, the smaller the received signal strength. If the optical signal transmitter and the optical signal receiver are arranged in a reflective position, the signal strength received by the optical signal receiver is the smallest when there is no oil smoke, and the greater the oil smoke concentration, the greater the received signal strength. Regardless of whether it is a facing arrangement or a reflective arrangement, through signal processing, subsequent signal analysis can be converted into the greater the oil smoke concentration, the greater the value output by the optical signal receiver.

[0033] When the oil fume is pure oil fume, the value change of the optical signal receiving device output is small, but due to the small particle radius and large gap between particles, the value jump of the optical signal receiving device output is more frequent. When the oil fume concentration is high or there is more water vapor, the value change of the optical signal receiving device output is large, but due to the small gap between oil particles, the frequency of value jump of the optical signal receiving device output is reduced. Therefore, the value change and value jump of the optical signal receiving device output can be used to reflect the volume concentration and number concentration of oil fume particles respectively, and then the oil fume concentration value can be determined from these two dimensions.

[0034] like Figure 1 As shown, the oil smoke detection method in this embodiment includes the following steps.

[0035] S1. Real-time acquisition of the fume concentration data D of the fume detection device. When working, the microprocessor acquires the real-time collected data DD of the optical signal receiver, that is, the real-time collection of the detection value DD of the fume detection device is realized. Then the microprocessor completes the D analysis calculation, compares DD with the current reference value B, and if DD<B, updates the reference value B=DD. If the range hood is used for the first time, an initial reference value will be pre-stored in the microprocessor. If within the set time length T1, the deviation / standard deviation of each collected detection value relative to the average value of these detection values ​​is less than the preset fluctuation threshold, then the updated reference value is judged to be the average value of these detection values. This T1 is greater than the time required for the range hood to be used normally once.

[0036] Then calculate D=DD-B.

[0037] S2. Calculate the change data ΔD=D-D0 of the current oil fume concentration data D relative to the oil fume concentration data D0 at the previous sampling time.

[0038] If |ΔD| is greater than the set change threshold ΔD0, ΔD0>0, and the sign of the current change data ΔD changes relative to the previously calculated change data, that is, the positive and negative signs of the change data before and after change, it is determined that a jump in the oil fume concentration data has occurred.

[0039] S3. Perform weighted calculation on the oil fume concentration data based on the read oil fume concentration data D and the jump condition, and then obtain the oil fume concentration value Dc.

[0040] Specifically, the following steps are included.

[0041] S3.1. Accumulate and calculate the number of jumps within a time range of T from the current time, where T is a set time threshold, and then obtain the jump number data sum within the range of T.

[0042] S3.2. Calculate the oil fume concentration influence amount A corresponding to the current jump number data sum according to the preset relationship between the jump number and the oil fume concentration influence amount. The relationship between the jump number and the oil fume concentration influence amount is obtained through multiple experiments during the product development stage. During the experiment, oil fume with known concentration and different particle sizes is sent into the range hood, and the oil fume concentration is detected using the aforementioned oil fume detection device, thereby obtaining the relationship between the jump number and the oil fume concentration influence amount.

[0043] When calculating the oil fume concentration detection value, the oil fume concentration data is weighted based on the read oil fume concentration data D and the jump number data sum. The calculation formula of the oil fume concentration value Dc is: Dc = k*D+(1-k)*A, where k is the weighting coefficient, 0 < k ≤ 1, and the larger D is, the larger k is.

[0044] The specific determination of k can be achieved by using any of the following two methods.

[0045] Method 1: preset a minimum oil fume concentration threshold Dmin and a maximum oil fume concentration threshold Dmax; preset a first weighting coefficient threshold k1 corresponding to Dmin, and preset a second weighting coefficient threshold k2 corresponding to Dmax; 0<k1≤k≤k2≤1.

[0046] The oil fume concentration interval [Dmin, Dmax] is divided into a plurality of continuous sub-oil fume concentration intervals, and a corresponding weighting coefficient ki is preset for each sub-oil fume concentration interval.

[0047] When D<Dmin, k=k1.

[0048] When D>Dmax, k=k2.

[0049] When Dmin≤D≤Dmax, the corresponding weighting coefficient ki is determined according to the oil fume concentration interval in which D is located.

[0050] Method 2: preset a minimum oil fume concentration threshold Dmin and a maximum oil fume concentration threshold Dmax; preset a first weighted coefficient threshold k1 corresponding to Dmin, and preset a second weighted coefficient threshold k2 corresponding to Dmax; 0<k1≤k≤k2≤1;

[0051] When D<Dmin, k=k1;

[0052] When D>Dmax, k=k2;

[0053] When Dmin≤D≤Dmax, k=k1+(k2-k1)*(D-Dmin) / (Dmax-Dmin).

[0054] The oil fume detection method of the present invention, based on obtaining the oil fume concentration data, determines the particle size of the oil fume by monitoring the jump situation of the data, so as to obtain the oil fume morphology information, and then uses the information to realize the scientific weighted calculation of the oil fume concentration data, thereby reflecting the influence of the oil fume particle size on the oil fume concentration data, and realizing the inspection of the oil fume concentration from two dimensions of oil fume particle volume concentration and particle number concentration, thereby obtaining a more accurate oil fume concentration value that can better reflect the nature of the oil fume, so as to deal with the oil fume in a more targeted manner.

Claims

1. A method for detecting oil smoke, characterized in that: The following steps are included Real-time acquisition of oil smoke concentration data D of the oil smoke detection device; Calculate the change data ΔD=D-D0 of the current oil smoke concentration data D relative to the oil smoke concentration data D0 at the previous sampling time; If |ΔD| is greater than the set change threshold ΔD0, ΔD0>0, and the sign of the current change data ΔD changes relative to the last calculated change data, it is determined that a jump in the fume concentration data occurs; The oil fume concentration data D is weighted based on the read oil fume concentration data and the jump condition, thereby obtaining the oil fume concentration value Dc; Accumulate the number of jumps within the time range of T from the current time, where T is the set time threshold, and then obtain the jump number data sum within the range of T; When calculating the oil smoke concentration detection value, the oil smoke concentration data is weightedly calculated based on the read oil smoke concentration data D and the jump number data sum; According to the preset relationship between the jump times and the smoke concentration influence, the smoke concentration influence A corresponding to the current jump times data sum is calculated; Calculate the oil smoke concentration value Dc=k*D+(1-k)*A, where k is the weighting coefficient, 0<k≤1, and the larger D is, the larger k is.

2. The oil smoke detection method according to claim 1, characterized in that: Preset the minimum oil fume concentration threshold Dmin and the maximum oil fume concentration threshold Dmax; A first weighting coefficient threshold k1 corresponding to Dmin is preset, and a second weighting coefficient threshold k2 corresponding to Dmax is preset; 0<k1≤k≤k2≤1; The oil fume concentration interval [Dmin, Dmax] is divided into a plurality of continuous oil fume concentration intervals, and a corresponding weighting coefficient ki is preset for each oil fume concentration interval; When D<Dmin, k= k1; When D>Dmax, k= k2; When Dmin≤D≤Dmax, the corresponding weighting coefficient ki is determined according to the oil fume concentration interval in which D is located.

3. The oil smoke detection method according to claim 1, characterized in that: Preset the minimum oil fume concentration threshold Dmin and the maximum oil fume concentration threshold Dmax; A first weighting coefficient threshold k1 corresponding to Dmin is preset, and a second weighting coefficient threshold k2 corresponding to Dmax is preset; 0<k1≤k≤k2≤1; When D<Dmin, k= k1; When D>Dmax, k= k2; When Dmin≤D≤Dmax, k=k1+(k2-k1)*(D-Dmin) / (Dmax-Dmin).

4. The oil smoke detection method according to any one of claims 1 to 3, characterized in that: The method for acquiring the oil smoke concentration data D is: collecting the detection value DD of the oil smoke detection device in real time, comparing DD with the current reference value B, and if DD<B, updating the reference value B=DD; If within the set time period T1, the deviation / standard deviation of each collected test value relative to the average value of these test values ​​is less than the preset fluctuation threshold, then the update reference value is determined to be the average value of these test values; D=DD-B.

5. A range hood using the oil smoke detection method according to any one of claims 1 to 4, characterized in that: The invention comprises a machine body with an oil fume passage, an optical signal transmitter and an optical signal receiver arranged in the oil fume passage, and a microprocessor arranged on the machine body, wherein the optical signal transmitter and the optical signal receiver are respectively connected with the microprocessor by electrical signals.

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