Range hood and control method thereof

Abstract

The invention relates to a range hood and a control method thereof, and the range hood comprises: a housing having an oil smoke channel; the two emitting devices comprise a first emitting device and a second emitting device which are arranged on the same inner wall of the oil smoke channel, and the first emitting device and the second emitting device emit pulse light which is parallel and different in color in the direction perpendicular to the airflow flowing direction; the two receiving devices comprise a first receiving device used for receiving the pulsed light emitted by the first emitting device and a second receiving device used for receiving the pulsed light emitted by the second emitting device, and the first receiving device and the second receiving device are arranged on the inner wall, opposite to the two emitting devices, of the oil smoke channel; the first receiving device and the first transmitting device are oppositely arranged, and the second receiving device and the second transmitting device are oppositely arranged; and the controller is electrically connected with the first receiving device and the second receiving device. The range hood can measure the airflow velocity, the oil smoke concentration and the water vapor concentration.

Description

Technical Field

[0001] The present invention relates to the technical field of oil fume purification, and in particular to a range hood and a control method thereof. Background Art

[0002] As an essential kitchen appliance in every household, the range hood draws in oil smoke from the air inlet through the high-speed rotating impeller in the volute, filters the oil smoke with the impeller, and discharges the filtered oil smoke from the air outlet to complete the kitchen air purification task.

[0003] The fan of a traditional range hood runs at a fixed gear or speed. Users manually select the required gear according to different scenarios such as stir-frying, steaming, etc. However, users generally have many different types of cooking actions in the cooking area, which will affect the smoke emission in the cooking area. For example, a lot of oil smoke or water vapor will be generated instantly when flipping the pan for stir-frying, putting vegetables in, and opening the lid of the pot. Traditional range hoods that run at a fixed gear or speed are difficult to adapt to such sudden scenarios.

[0004] To solve the above technical problems, a Chinese utility model patent with patent number ZL201922181387.6 (authorization announcement number CN211290212U) discloses an automatic start-stop oil fume purification integrated machine, including a hood, an oil fume purifier and a fan, as well as a detection device and a manual switch. The fan includes a low-power state and a high-power state. The manual switch is used to control the fan to first turn on the low-power state. The detection device is used to detect oil fume and water vapor in the air in the kitchen. If oil fume is detected, a first feedback signal is issued. If only water vapor is detected, a second feedback signal is issued. The controller of the oil fume purifier controls the start of the oil fume purifier and the fan to turn on the high-power state in response to the first feedback signal. The controller of the oil fume purifier controls the stop of the oil fume purifier and the fan to turn off the high-power state in response to the second feedback signal.

[0005] Although the above-mentioned oil fume purification all-in-one machine can detect oil fume and water vapor in the air in the kitchen through humidity sensors and smoke sensors, the smoke sensor detects the smoke concentration based on the change in light flux or scattering when smoke is present. If the oil fume and water vapor are mixed, it is impossible to distinguish between water vapor and oil fume, resulting in inaccurate scene judgment. In addition, 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 lead to 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. For this reason, further improvements to the existing technology are needed. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to provide a range hood that can accurately distinguish between water vapor and oil smoke in the oil smoke channel and can detect air flow velocity without the need for an additional flow sensor, in response to the above-mentioned existing technology.

[0007] The second technical problem to be solved by the present invention is to provide a control method for the above-mentioned range hood, which can realize automatic control of different cooking scenes and dynamically adjust the fan gear of the range hood.

[0008] The technical solution adopted by the present invention to solve the first technical problem is: a range hood comprising:

[0009] The casing has an oil smoke passage;

[0010] It is characterized by also including:

[0011] Two emitting devices, including a first emitting device and a second emitting device, both of which are arranged on the same inner wall of the oil fume duct, the first emitting device and the second emitting device both emit pulsed light in a direction perpendicular to the flow direction of the airflow, and the pulsed light emitted by the first emitting device is parallel to the pulsed light emitted by the second emitting device and has a different color;

[0012] Two receiving devices, including a first receiving device and a second receiving device, both of which are arranged on the same inner wall of the oil fume passage, the first receiving device and the second receiving device are arranged on the inner wall of the oil fume passage opposite to the two transmitting devices, the first receiving device is arranged opposite to the first transmitting device, and the second receiving device is arranged opposite to the second transmitting device, the first receiving device is used to receive the pulse light emitted by the first transmitting device, and the second receiving device is used to receive the pulse light emitted by the second transmitting device;

[0013] The controller is electrically connected to the first receiving device and the second receiving device, and is configured to analyze the results received by the first receiving device and the second receiving device to obtain the air flow velocity in the oil fume channel and the water vapor and oil fume conditions in the oil fume channel.

[0014] Preferably, one of the first emitting device and the second emitting device emits red pulse light, and the other emits blue pulse light.

[0015] In order to improve the linearity of light, a collimating lens is provided at the front end of the first emitting device and the second emitting device.

[0016] In order to reduce interference, bandpass filters are provided at the front ends of the first receiving device and the second receiving device.

[0017] Preferably, the wavelength of the bandpass filter at the front end of the first receiving device is substantially the same as the wavelength of the pulse light of the first transmitting device, and the wavelength of the bandpass filter at the front end of the second receiving device is substantially the same as the wavelength of the pulse light of the second transmitting device.

[0018] The technical solution adopted by the present invention to solve the second technical problem is: a control method for the range hood as described above, wherein a fan is provided in the housing, and the method is characterized by comprising the following steps:

[0019] Step 1: Control the first transmitting device, the second transmitting device, the first receiving device, and the second receiving device to operate;

[0020] Step 2: By collecting the results received by the first receiving device and the second receiving device and analyzing the results received by the first receiving device and the second receiving device, the airflow velocity V in the oil smoke channel is obtained. 实 , water vapor concentration C in the oil fume channel 水 And the fume concentration C in the fume channel 油 ;

[0021] Step 3: According to the water vapor concentration C in the oil smoke channel 水 And the fume concentration C in the fume channel 油 The value of is used to judge the water vapor and oil smoke conditions in the oil smoke channel, and then the fan is controlled to perform corresponding actions according to the water vapor and oil smoke conditions in the oil smoke channel;

[0022] Step 4: Obtain the airflow velocity V in the oil smoke channel according to step 2 实 The fan's working gear is adjusted according to the required flow rate in the current working scenario.

[0023] Preferably, the air flow velocity V in the oil fume channel in step 2 is 实 The calculation formula is:

[0024]

[0025] Wherein, ΔL is the distance between the first transmitting device and the second transmitting device, and Δt is the valley time difference between the first receiving device and the second receiving device receiving the pulse signal.

[0026] Preferably, the water vapor concentration C in the oil smoke channel in step 2 is 水 And the fume concentration C in the fume channel 油 The specific way to obtain it is:

[0027] Solve C according to the following two formulas 水 and C 油 ;

[0028]

[0029] Where I1 and I2 are the light intensities actually received by the first receiving device and the second receiving device, respectively. 0,1 and I 0,2 are the light intensities emitted by the first emitting device and the second emitting device, α 1 油 and α 2 油 are the absorption coefficients of oil smoke to the first emitting device and the pulse light emitted by the first emitting device, α 1 水 and α 2 水 are the absorption coefficients of water vapor to the first emitting device and the pulse light emitted by the first emitting device, respectively, and L is the distance from the pulse light emission to the pulse light reception.

[0030] Preferably, the specific control logic of step 3 is:

[0031] When C 水 ≥C c And C 油 <C b , then the current oil smoke channel is mainly water vapor, and the fan is controlled to run at low gear;

[0032] When C 油 <C b And C 水 <C c , then there is basically no oil smoke and water vapor in the oil smoke channel, and the fan is controlled to be closed;

[0033] When C 油 ≥C b , then the current oil smoke channel is mainly oil smoke, and the fan is controlled to run at medium or high gear;

[0034] Among them C c and C b All are preset constants.

[0035] Preferably, when the oil smoke channel is mainly oil smoke, it is divided into the following two cases: when C b ≤C 油 ≤C a , the oil smoke in the current oil smoke channel is low concentration oil smoke, and the fan is controlled to run at the middle speed; when C 油 >C a , the oil smoke in the current oil smoke channel is high concentration oil smoke, and the fan is controlled to run at a high speed; where C a is a preset constant.

[0036] Compared with the prior art, the advantages of the present invention are as follows: by providing two transmitting devices and two receiving devices within the oil fume duct, with the first receiving device being used to receive the pulsed light emitted by the first transmitting device and the second receiving device being used to receive the pulsed light emitted by the second transmitting device, the pulsed light emitted by the first transmitting device is parallel to the pulsed light emitted by the second transmitting device and has a different color, thereby accurately distinguishing the water vapor and oil fume in the oil fume duct by utilizing the difference in the absorption rate of oil fume and water vapor for pulsed light of different wavelengths. In addition, the flow rate can be calculated based on the interval time between the oil fume and water vapor air masses blocking the two light paths, and then the airflow rate, oil fume concentration, and water vapor concentration can be measured using a single detection device, without the need for an additional flow sensor to detect the airflow rate. Therefore, the range hood can accurately identify different cooking scenarios and adjust the fan gear according to the different cooking scenarios, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the use of the range hood in an embodiment of the present invention;

[0038] Figure 2 Schematic diagram of the operation of two transmitting devices and two receiving devices in an embodiment of the present invention;

[0039] Figure 3 Another working schematic diagram of two transmitting devices and two receiving devices in an embodiment of the present invention;

[0040] Figure 4 is a schematic diagram of two receiving devices receiving signals according to an embodiment of the present invention;

[0041] Figure 5 Flowchart of the range hood control method in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0043] like Figure 1 As shown, the range hood in this embodiment includes a housing 1 and a fan (not shown in the figure), the housing 1 has an oil smoke passage 10, and the fan is arranged in the oil smoke passage 10. The fan adopts the existing technology and will not be described in detail here. A stove a is arranged below the range hood.

[0044] The range hood in this embodiment further includes two transmitting devices, two receiving devices and a controller (not shown in the figure). Figures 1 to 3As shown, the two emitting devices include a first emitting device 21 and a second emitting device 22, both of which are arranged on the same inner wall of the oil smoke passage 10. The first emitting device 21 and the second emitting device 22 both emit pulsed light in a direction perpendicular to the airflow direction. The pulsed light emitted by the first emitting device 21 is parallel to the pulsed light emitted by the second emitting device 22 and has different colors. The two receiving devices include a first receiving device 31 and a second receiving device 32, both of which are arranged on the same inner wall of the oil smoke passage 10. The first receiving device 31 and the second receiving device 32 are arranged in the inner wall of the oil smoke passage 10 opposite to the two emitting devices. On the wall, the first receiving device 31 is arranged opposite to the first emitting device 21, and the second receiving device 32 is arranged opposite to the second emitting device 22. The first receiving device 31 is used to receive the pulse light emitted by the first emitting device 21, and the second receiving device 32 is used to receive the pulse light emitted by the second emitting device 22; the controller is electrically connected to the first receiving device 31 and the second receiving device 32, and the controller is configured to: analyze the results received by the first receiving device 31 and the second receiving device 32, and obtain the airflow velocity in the oil fume duct 10 and the water vapor and oil fume conditions in the oil fume duct 10.

[0045] One of the first emitting device 21 and the second emitting device 22 emits red pulsed light, while the other emits blue pulsed light. In this embodiment, the first emitting device 21 emits red pulsed light with a wavelength of 660 nm, while the second emitting device 22 emits blue pulsed light with a wavelength of 450 nm. To improve the linearity of the light, collimating lenses 4 are provided at the front ends of both the first emitting device 21 and the second emitting device 22.

[0046] The front ends of the first receiving device 31 and the second receiving device 32 are both provided with a bandpass filter 5. The wavelength of the bandpass filter 5 at the front end of the first receiving device 31 is substantially the same as the wavelength of the pulsed light of the first transmitting device 21, and the wavelength of the bandpass filter 5 at the front end of the second receiving device 32 is substantially the same as the wavelength of the pulsed light of the second transmitting device 22. In this embodiment, the wavelength of the bandpass filter 5 at the front end of the first receiving device 31 is 660nm±5nm; the wavelength of the bandpass filter 5 at the front end of the second receiving device 32 is 450nm±5nm. In this embodiment, the first receiving device 31 and the second receiving device 32 can be cameras with COMS sensors or photoelectric sensors. Bandpass filters can reduce interference from ambient light and mutual interference between red pulsed light and blue pulsed light. Common manufacturing processes such as coating technology can achieve bandpass spectral separation on a single glass substrate.

[0047] like Figure 5 As shown, this embodiment also relates to a control method for the range hood, which includes the following steps:

[0048] Step 1: Control the first transmitting device, the second transmitting device, the first receiving device, and the second receiving device to operate;

[0049] In this embodiment, before step 1, the method further includes controlling whether the range hood is in manual operation or intelligent mode, and if the intelligent mode is turned on, starting the intelligent monitoring mode;

[0050] Step 2: By collecting the results received by the first receiving device and the second receiving device and analyzing the results received by the first receiving device and the second receiving device, the airflow velocity V in the oil smoke channel is obtained. 实 , water vapor concentration C in the oil fume channel 水 And the fume concentration C in the fume channel 油 ;

[0051] In this embodiment, the air flow velocity V in the oil fume channel is 实 The calculation formula is:

[0052]

[0053] Wherein, ΔL is the distance between the first transmitting device and the second transmitting device, and Δt is the valley time difference between the first receiving device and the second receiving device receiving the pulse signal;

[0054] like Figure 2 As shown in the figure, during normal cooking, the air masses formed by oil smoke and water vapor pass through two types of light paths successively and are absorbed successively to form reception valleys with time differences. Figure 2 The middle part is after passing through the blue light path. At this time, the blue light is normal. The red light is absorbed more and forms an obvious reception valley (reception low point) for the red light. Figure 3 As shown in the figure, during normal cooking, the air masses formed by oil smoke and water vapor pass through two types of light paths successively and are absorbed successively to form reception valleys with time differences. Figure 3 When it passes through the blue light path first and has not yet passed through the red light; Figure 4 As shown, the first receiving device and the second receiving device generate two pulse signals when receiving, and the valley time difference between the two can be obtained as Δt; because the distance between the two optical paths of the first transmitting device and the second transmitting device is known as ΔL, the airflow in the oil smoke channel is mainly in the upward direction, and the lateral component can be ignored when the cross-sectional area does not change significantly. Therefore, the airflow velocity V can be obtained according to the above calculation formula. 实 ;

[0055] In this embodiment, the water vapor concentration C in the oil smoke channel is 水 And the fume concentration C in the fume channel 油 The specific way to obtain it is:

[0056] Solve C according to the following two formulas 水 and C油 ;

[0057]

[0058] Where I1 and I2 are the light intensities actually received by the first receiving device and the second receiving device, respectively. 0,1 and I 0,2 are the light intensities emitted by the first emitting device and the second emitting device, α 1 油 and α 2 油 are the absorption coefficients of oil smoke to the first emitting device and the pulse light emitted by the first emitting device, α 1 水 and α 2 水 are the absorption coefficients of water vapor to the first emitting device and the pulse light emitted by the first emitting device, respectively, and L is the distance from the pulse light emission to the pulse light reception;

[0059] When light of different wavelengths passes through oil smoke, water mist, etc., its attenuation characteristics are closely related to the ratio of particle size and light wavelength. Experimental measurements show that oil smoke attenuates blue light most significantly, while water mist attenuates red light even more significantly. Therefore, the dual-wavelength Beer-Lambert law correction model can be combined to obtain pollutant concentration values based on the relationship between received light intensity and emitted light intensity, thereby further distinguishing between scenes dominated by water vapor or oil smoke. The above-mentioned absorption coefficients can be calibrated in the laboratory for standard absorption coefficients.

[0060] Step 3: According to the water vapor concentration C in the oil smoke channel 水 And the fume concentration C in the fume channel 油 The value of is used to judge the water vapor and oil smoke conditions in the oil smoke channel, and then the fan is controlled to perform corresponding actions according to the water vapor and oil smoke conditions in the oil smoke channel;

[0061] The specific control logic of step 3 is:

[0062] When C 水 ≥C c And C 油 <C b , then the current oil smoke channel is mainly water vapor, and the fan is controlled to run at low gear;

[0063] When C 油 <C b And C 水 <C c , then there is basically no oil smoke and water vapor in the oil smoke channel, and the fan is controlled to be closed;

[0064] When C 油 ≥C b, then the current oil smoke channel is mainly oil smoke, and the fan is controlled to run at medium or high gear;

[0065] When the oil fume channel is mainly oil fume, it can be divided into the following two situations:

[0066] When C b ≤C 油 ≤C a , the oil smoke in the current oil smoke channel is low concentration oil smoke, and the fan is controlled to run at the middle speed;

[0067] When C 油 >C a , the oil smoke in the current oil smoke channel is high-concentration oil smoke, and the fan is controlled to run at a high speed;

[0068] Among them C a 、C b and C c All are preset constants;

[0069] C a 、C b and C c The specific value of can be determined by experience or experiment. In addition, in this embodiment, the fan has three gears, and the higher the gear, the higher the fan speed. The above low gear, medium gear and high gear are all relative.

[0070] Step 4: Obtain the airflow velocity V in the oil smoke channel according to step 2 实 The fan's working gear is adjusted according to the required flow rate in the current working scenario.

[0071] In this embodiment, if the current oil fume channel is mainly composed of water vapor, the current working scene is a steaming scene; if the current oil fume channel is basically free of oil fume and water vapor, the current working scene is an idle state; if the current oil fume channel is mainly composed of oil fume, the current working scene is stir-frying or frying; the required flow rate and the fan working gear under different working scenes can be stored in a table, that is, whether the fan working gear needs to be adjusted can be determined by looking up the table.

[0072] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A range hood comprising: The housing (1) has an oil smoke passage (10); It is characterized by also including: Two emitting devices, including a first emitting device (21) and a second emitting device (22), both of which are arranged on the same inner wall of the oil smoke channel (10), wherein the first emitting device (21) and the second emitting device (22) both emit pulsed light in a direction perpendicular to the flow direction of the airflow, and the pulsed light emitted by the first emitting device (21) and the pulsed light emitted by the second emitting device (22) are parallel and have different colors; Two receiving devices, including a first receiving device (31) and a second receiving device (32), both of which are arranged on the same inner wall of the oil smoke passage (10); the first receiving device (31) and the second receiving device (32) are arranged on the inner wall of the oil smoke passage (10) opposite to the two transmitting devices; the first receiving device (31) is arranged opposite to the first transmitting device (21); the second receiving device (32) is arranged opposite to the second transmitting device (22); the first receiving device (31) is used to receive the pulse light emitted by the first transmitting device (21); and the second receiving device (32) is used to receive the pulse light emitted by the second transmitting device (22); A controller is electrically connected to the first receiving device (31) and the second receiving device (32), and is configured to analyze the results received by the first receiving device (31) and the second receiving device (32) to obtain the air flow velocity in the oil smoke channel (10) and the water vapor and oil smoke conditions in the oil smoke channel (10).

2. The range hood according to claim 1, characterized in that: One of the first emitting device (21) and the second emitting device (22) emits red pulse light, and the other emits blue pulse light.

3. The range hood according to claim 1, wherein: The front ends of the first emitting device (21) and the second emitting device (22) are both provided with collimating lenses (4).

4. The range hood according to any one of claims 1 to 3, characterized in that: The front ends of the first receiving device (31) and the second receiving device (32) are both provided with bandpass filters (5).

5. The range hood according to claim 4, characterized in that: The wavelength of the bandpass filter (5) at the front end of the first receiving device (31) is substantially the same as the wavelength of the pulse light of the first transmitting device (21), and the wavelength of the bandpass filter (5) at the front end of the second receiving device (32) is substantially the same as the wavelength of the pulse light of the second transmitting device (22).

6. A control method for a range hood according to any one of claims 1 to 5, wherein a fan is provided in the housing, characterized in that The steps include: Step 1: Control the first transmitting device, the second transmitting device, the first receiving device, and the second receiving device to operate; Step 2: By collecting the results received by the first receiving device and the second receiving device and analyzing the results received by the first receiving device and the second receiving device, the airflow velocity V in the oil smoke channel is obtained. 实 , water vapor concentration C in the oil fume channel 水 And the fume concentration C in the fume channel 油 ; Step 3: According to the water vapor concentration C in the oil smoke channel 水 And the fume concentration C in the fume channel 油 The value of is used to judge the water vapor and oil smoke conditions in the oil smoke channel, and then the fan is controlled to perform corresponding actions according to the water vapor and oil smoke conditions in the oil smoke channel; Step 4: Obtain the airflow velocity V in the oil smoke channel according to step 2 实 The fan's working gear is adjusted according to the required flow rate in the current working scenario.

7. The control method according to claim 6, characterized in that: The air flow velocity V in the oil fume channel in step 2 实 The calculation formula is: Wherein, ΔL is the distance between the first transmitting device and the second transmitting device, and Δt is the valley time difference between the first receiving device and the second receiving device receiving the pulse signal.

8. The control method according to claim 6, wherein: The water vapor concentration C in the oil fume channel in step 2 水 And the fume concentration C in the fume channel 油 The specific way to obtain it is: Solve C according to the following two formulas 水 and C 油 ; Where I1 and I2 are the light intensities actually received by the first receiving device and the second receiving device, respectively. 0,1 and I 0,2 are the light intensities emitted by the first emitting device and the second emitting device, α 1 油 and α 2 油 are the absorption coefficients of oil smoke to the first emitting device and the pulse light emitted by the first emitting device, α 1 水 and α 2 水 are the absorption coefficients of water vapor to the first emitting device and the pulse light emitted by the first emitting device, respectively, and L is the distance from the pulse light emission to the pulse light reception.

9. The control method according to any one of claims 6 to 8, characterized in that: The specific control logic of step 3 is: When C 水 ≥C c And C 油 <C b , then the current oil smoke channel is mainly water vapor, and the fan is controlled to run at low gear; When C 油 <C b And C 水 <C c , then there is basically no oil smoke and water vapor in the oil smoke channel, and the fan is controlled to be closed; When C 油 ≥C b , then the current oil smoke channel is mainly oil smoke, and the fan is controlled to run at medium or high gear; Among them C c and C b All are preset constants.

10. The control method according to claim 9, characterized in that: When the oil smoke channel is mainly oil smoke, it can be divided into the following two situations: b ≤C 油 ≤C a , the oil smoke in the current oil smoke channel is low concentration oil smoke, and the fan is controlled to run at the middle speed; when C 油 >C a , the oil smoke in the current oil smoke channel is high concentration oil smoke, and the fan is controlled to run at a high speed; where C a is a preset constant.

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