Range hood filter blockage detection method and range hood

Abstract

This invention relates to a method for detecting filter clogging in a range hood and a range hood itself. The method involves obtaining the filter clogging status through the following steps: Step 1: After the range hood filter is installed, the filter clogging detection function is activated, and the wind speed difference V0 at different operating speeds behind the filter is measured. Step 2: During use after installation, if the filter clogging detection function is activated again, the wind speed difference V1 at different operating speeds behind the filter is calculated. Step 3: The percentage of clogged area of ​​the range hood filter at the current moment is calculated as X%: X% = 100% - Y%, where Y% = V0 / V1. Compared with existing technologies, the advantages of this invention are: it can largely offset the errors caused by environmental factors, resulting in more accurate measurement results, a lower probability of false alarms, and better stability and reliability.

Description

Technical Field

[0001] The invention relates to a range hood filter blockage detection method and a range hood. Background Art

[0002] In recent years, with the improvement of people's quality of life, the requirements for range hoods that are free of cleaning or easy to clean have become higher and higher. Therefore, in order to ensure that the interior of the range hood is free of cleaning or to extend the maintenance period, the range hood has gradually been equipped with relevant functions or structures. There are two main ways: one is to pollute first and then treat. When the internal pollution reaches a certain level, the internal parts are cleaned through the corresponding self-cleaning function module; the other is to extend the maintenance-free period of the interior by improving the filtration efficiency of the pre-filter.

[0003] As for the pre-filter, in order to further improve the filtration efficiency, the filter has gradually transitioned from the previous grille-type mesh to diamond-shaped holes with higher perforation rate, and then to round holes with higher density and better perforation rate. Now, multi-layer composite filters have begun to appear, such as the composite of grille mesh and small round hole filter, and the composite of grille mesh and porous material filter. In short, in order to improve the filtration efficiency, the pre-filter has gradually developed in the direction of multi-layer and intensive. However, while the filter improves the filtration efficiency, the collision interception opportunity of the mesh is greater and the mesh is smaller, so the probability of filter blockage also increases. The blockage of the air inlet of the filter will cause the performance of the range hood to be significantly reduced, the oil fume extraction effect is significantly reduced, and the oil fume escape cannot be inhaled in time. At the same time, the noise of the range hood also increases significantly. Therefore, this type of intensive filter needs to be cleaned or replaced regularly. For users, when to clean and when to replace, users cannot clearly grasp it. Execution too early will waste resources, and execution too late will affect the kitchen environment and health.

[0004] At present, the most commonly used method for detecting the blockage of the range hood filter is to determine the blockage of the filter by detecting the wind pressure, air volume, or light intensity at the air inlet. Some will jointly detect the wind pressure and oil smoke concentration to determine the blockage of the filter. The detection principle is: when the filter is first installed, the corresponding physical quantity is detected once, and after a period of use, it is tested again, and the blockage of the filter is determined by the relationship between the two determinations.

[0005] As for the above methods, what is detected is an absolute quantity, that is, the filter condition is judged by judging the relationship between the physical quantity when the filter is not in use and when the filter is blocked. There are great differences in the external factors such as the kitchen environment and flue pressure during the two tests. Therefore, the physical quantities of the two tests actually include increments caused by some influencing factors. Assuming that the environment is a standard environment for the first test, if the environment is not a standard environment for the second test, then even if the filter is not in use, the physical quantity detected will be inconsistent with the previous one. According to the data, the filter is blocked at this time, but it is not actually blocked. Therefore, the absolute quantity detected is greatly affected by the environment and has a very low accuracy. Wind pressure and air volume will be affected by the public flue, i.e. the kitchen environment during the test; oil fume concentration will be affected by cooking; and light intensity detection will be affected by the light intensity in the kitchen. Summary of the invention

[0006] The first technical problem to be solved by the present invention is to provide a range hood filter clogging detection method that can eliminate the error caused by environmental factors and make the measurement more accurate, with respect to the above-mentioned prior art.

[0007] The second technical problem to be solved by the present invention is to provide a range hood with a filter clogging detection function which can eliminate the error caused by environmental factors and make the measurement more accurate, in view of the above-mentioned prior art.

[0008] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a method for detecting the clogging of a range hood filter, characterized in that the clogging status of the range hood filter is obtained through the following steps:

[0009] Step 1: After the range hood filter is installed, start the filter blockage detection function and measure the wind speed difference V0 at different working gears behind the range hood filter, including:

[0010] Step 1.1, first make the range hood stably run at the first working gear, and then obtain the wind speed value behind the filter of the range hood at this time, which is recorded as V11;

[0011] Step 1.2, switching the working gear of the range hood to make the range hood stably run at the second working gear, and then obtaining the wind speed value behind the filter of the range hood at this time, recorded as V12; wherein the second working gear is different from the first working gear;

[0012] Step 1.3, calculate the wind speed difference V0=|V11-V12| at different working gears behind the range hood filter;

[0013] Step 2: During the use of the range hood filter after installation, if the filter blockage detection function is started again, the blockage area ratio of the range hood filter at the current moment is obtained, which includes:

[0014] Step 2.1, first make the range hood stably operate at the first working gear, and then obtain the wind speed value behind the filter of the range hood at this time, which is recorded as V21;

[0015] Step 2.2, switching the working gear of the range hood to make the range hood stably run at the second working gear, and then obtaining the wind speed value behind the filter of the range hood at this time, which is recorded as V22; wherein the second working gear is different from the first working gear;

[0016] Step 2.3, calculate the wind speed difference V1=|V21-V22| at different working gears behind the range hood filter at the current moment;

[0017] Step 2.4, calculate the current moment the range hood filter blockage area accounts for X%:

[0018] X%=100%-Y%, where Y%=V0 / V1.

[0019] As an improvement, N wind speed sampling points at different positions are provided on the rear side of the range hood filter;

[0020] The V11 measured in step 1.1 includes the wind speed values ​​of the N different wind speed sampling points, and V11=V 11i , where i represents the sampling position, i=1, 2, ... N, N is a natural number greater than or equal to 2;

[0021] V21 measured in step 1.2 includes the wind speed values ​​of the N different wind speed sampling points, and V12 = V 12i , where i represents the sampling position, i=1, 2, ... N, N is a natural number greater than or equal to 2;

[0022] In step 1.3,

[0023] The V21 measured in step 2.1 includes the wind speed values ​​of the N different wind speed sampling points, and V21=V 21i , where i represents the sampling position, i=1, 2, ... N, N is a natural number greater than or equal to 2;

[0024] V22 measured in step 2.2 includes the wind speed values ​​of the N different wind speed sampling points, and V22 = V 22i , where i represents the sampling position, i=1, 2, ... N, N is a natural number greater than or equal to 2;

[0025] In step 2.3,

[0026] Further improvement, the V 11i 、V 12i 、V 21i 、V 22iThey are all the average values ​​of n samples, where n is a natural number greater than or equal to 2.

[0027] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a range hood, comprising a casing, a fan system arranged inside the casing, an air inlet connected to the inlet of the fan system is provided on the casing, and a filter is provided at the air inlet, characterized in that: a filter detection device for detecting the blockage state of the filter is also provided on the casing, the filter detection device comprises a wind speed detection device arranged on the rear side of the filter, and the filter detection device detects the blockage state of the filter by adopting the above-mentioned range hood filter blockage detection method.

[0028] As an improvement, a display device is provided on the casing, and the filter detection device is communicatively connected to the display device. When the range hood starts the filter blockage detection function, the filter detection device will display the calculated X% of the range hood filter blockage area at the current moment through the display device.

[0029] As a further improvement, during the use of the range hood filter after installation, the filter clogging detection function is activated in the delayed shutdown state of the range hood.

[0030] As a further improvement, during the use of the range hood filter after installation, the detection frequency of the filter blockage detection function is set to: initially once a week, when the blockage area of ​​the range hood filter accounts for X% and reaches a first preset threshold, the detection frequency is changed to once a day, and the first preset threshold is 30% to 50%.

[0031] Further improvement, the first working gear is a strong gear, and the second working gear is a weak gear.

[0032] Further improved, the filter detection device includes N wind speed sensors respectively arranged at N different wind speed sampling points on the rear side of the range hood filter, and an electronic control device communicatively connected to the N wind speed sensors, and the electronic control device is used to calculate the proportion of X% of the range hood filter blockage area at the current moment based on the wind speed values ​​collected by the N wind speed sensors.

[0033] Further improved, the filter detection device includes a wind speed sensor arranged on the rear side of the range hood filter, a driving device connected to the wind speed sensor and used for driving the wind speed sensor to and from N wind speed sampling points at different positions, and an electronic control device communicatively connected to the wind speed sensor, the electronic control device being used for calculating X% of the blockage area of ​​the range hood filter at the current moment based on the wind speed value collected by the wind speed sensor.

[0034] Further improvement, the driving device includes a base, a driving motor, a guide rail, a guide rail slider and a bracket, the base is fixed on the casing, the driving motor is fixed on the base, the guide rail is also arranged on the base, the guide rail slider is slidably set on the guide rail, the guide rail slider is connected to the driving motor through a transmission assembly and can slide along the guide rail when driven by the driving motor, the bracket is fixed on the guide rail slider, and the wind speed sensor is fixed on the bracket.

[0035] As a further improvement, the transmission assembly includes a screw nut pair and a coupling, the drive motor is connected to the screw nut pair via the coupling, and the guide rail slider is fixedly connected to the nut slider of the screw nut pair.

[0036] As a further improvement, the screw length of the screw nut pair is greater than the length of the filter screen, and the sliding stroke of the guide rail slider is greater than the length of the filter screen.

[0037] As a further improvement, one end of the travel of the guide rail slider on the guide rail is directly opposite to the edge of one side of the filter screen, and the other end of the travel of the guide rail slider on the guide rail exceeds the edge of the other side of the filter screen by 50-100 mm.

[0038] In a further improvement, the wind speed sensor moves back and forth between N wind speed sampling points, and the N wind speed sampling points are located on the horizontal center line of the filter.

[0039] As a further improvement, after each detection of the filter detection device is completed, the wind speed sensor returns to the initial position and waits for the next detection. The initial position of the wind speed sensor avoids the air inlet and the entrance of the fan system, and the detection head of the wind speed sensor is blocked by the inner wall of the casing.

[0040] As a further improvement, if the blocked area of ​​the range hood filter accounts for X% at the current moment and reaches a second preset threshold value, the second preset threshold value is 50% to 70%, the display device displays a red aperture to remind the user to replace and clean the filter.

[0041] For further improvement, if the blockage area of ​​the range hood filter accounts for X% at the current moment and reaches a third preset threshold value, the third preset threshold value is 30% to 40%, the filter detection device adds a function to determine which side of the left or right side of the filter is more seriously clogged, namely: calculate the average wind speed difference of the N / 2 wind speed sampling points on the left side at different working gears and the average wind speed difference of the N / 2 wind speed sampling points on the right side at different working gears, and determine which of the average wind speed difference on the left side and the average wind speed difference on the right side is larger, then it is determined that the filter on this side is more seriously clogged than the filter on the other side.

[0042] As a further improvement, the range hood further comprises a self-cleaning device for automatically cleaning the filter.

[0043] As a further improvement, the self-cleaning device is communicatively connected with the filter detection device. When the filter detection device detects that the blockage area of ​​the range hood filter accounts for X% at the current moment and reaches a fourth preset threshold value, the fourth preset threshold value is 50% to 70%, the self-cleaning device starts and then automatically cleans the filter.

[0044] Further improvement, the self-cleaning device includes a nozzle arranged on one side of the filter, the nozzle is provided with a plurality of injection ports arranged along the length direction thereof, the length direction of the nozzle is parallel to the width direction of the filter, the length of the nozzle is greater than or equal to the width of the filter, the inlet of the nozzle is connected to a water supply device or a water steam supply device through a pipeline, the nozzle is connected to a reciprocating drive device, and the reciprocating drive device can drive the nozzle to reciprocate along the length direction of the filter.

[0045] As a further improvement, the water supply device includes a water box and a water pump, or the water steam supply device includes a water box, a water pump and a heater.

[0046] As a further improvement, the reciprocating drive device includes a driving wheel arranged on one side of the filter, the driving wheel is connected to the output shaft of the cleaning motor and is driven to rotate by the cleaning motor, and a driven wheel arranged on the other side of the filter is connected to the nozzle, and the driving windings at both ends are respectively wound around the driving wheel and the driven wheel.

[0047] As a further improvement, the reciprocating drive device also includes cleaning guide rails arranged on both sides of the nozzle, and the two sides of the nozzle can slide in the cleaning guide rails.

[0048] Compared with the prior art, the advantages of the present invention are: the state of the filter is reflected by the wind speed difference behind the filter at different working gears of the range hood. By making the wind speed difference, the error caused by environmental factors is offset to a large extent, making the measurement result more accurate, reducing the probability of false alarms, and improving stability and reliability. In the improved scheme, data is collected at multiple positions behind the filter at the same time, and the average value is used to reflect the state of the filter at this moment. While avoiding false alarms, the influence of local vortices on the edge of the filter on the detection is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Flow chart of a range hood filter clogging detection method in an embodiment of the present invention.

[0050] Figure 2 Schematic diagram of the structure of the range hood in the embodiment of the present invention.

[0051] Figure 3 Schematic diagram of the internal structure of the range hood in an embodiment of the present invention.

[0052] Figure 4 Schematic diagram of the structure of the filter detection device in an embodiment of the present invention.

[0053] Figure 5Schematic diagram of the structure of the self-cleaning device in an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below with reference to the accompanying drawings.

[0055] like Figure 1 The range hood filter clogging detection method shown in the figure obtains the range hood filter clogging status through the following steps:

[0056] Step 1: After the range hood filter is installed, start the filter blockage detection function and measure the wind speed difference V0 at different working gears behind the range hood filter, including:

[0057] Step 1.1, first make the range hood run stably at the strong gear, and then obtain the wind speed value behind the filter of the range hood at this time, which is recorded as V11;

[0058] Step 1.2, switch the working gear of the range hood to make the range hood run stably at the weak gear, and then obtain the wind speed value behind the filter of the range hood at this time, which is recorded as V12;

[0059] Step 1.3, calculate the wind speed difference V0=|V11-V12| at different working gears behind the range hood filter;

[0060] Step 2: During the use of the range hood filter after installation, if the filter blockage detection function is started again, the blockage area ratio of the range hood filter at the current moment is obtained, which includes:

[0061] Step 2.1, first make the range hood stably operate at the first working gear, and then obtain the wind speed value behind the filter of the range hood at this time, which is recorded as V21;

[0062] Step 2.2, switching the working gear of the range hood to make the range hood stably run at the second working gear, and then obtaining the wind speed value behind the filter of the range hood at this time, which is recorded as V22; wherein the second working gear is different from the first working gear;

[0063] Step 2.3, calculate the wind speed difference V1=|V21-V22| at different working gears behind the range hood filter at the current moment;

[0064] Step 2.4, calculate the current moment the range hood filter blockage area accounts for X%:

[0065] X%=100%-Y%, where Y%=V0 / V1.

[0066] In this embodiment, N wind speed sampling points at different positions are arranged on the rear side of the range hood filter, and the value of N is preferably 5;

[0067] The V11 measured in step 1.1 includes the wind speed values ​​of the N different wind speed sampling points, and V11=V 11i , where i represents the sampling position, i = 1, 2, ... N; V 11i is the average value of n wind speed values ​​collected at different times within a continuous period of time (such as 1 minute) at the i-th wind speed sampling point, and n is preferably 10;

[0068] V21 measured in step 1.2 also includes the wind speed values ​​of the N different wind speed sampling points, and V12 = V 12i , where i represents the sampling position, i = 1, 2, ... N; V 12i is the average value of n wind speed values ​​collected at different times within a continuous period of time (such as 1 minute) at the i-th wind speed sampling point, and n is preferably 10;

[0069] In step 1.3, i = 1, 2, ... N;

[0070] The V21 measured in step 2.1 includes the wind speed values ​​of the N different wind speed sampling points, and V21=V 21i , where i represents the sampling position, i = 1, 2, ... N; V 21i is the average value of n wind speed values ​​collected at different times within a continuous period of time (such as 1 minute) at the i-th wind speed sampling point, and n is preferably 10;

[0071] V22 measured in step 2.2 includes the wind speed values ​​of the N different wind speed sampling points, and V22 = V 22i , where i represents the sampling position, i = 1, 2, ... N, N is a natural number greater than or equal to 2; V 22i is the average value of n wind speed values ​​collected at different times within a continuous period of time (such as 1 minute) at the i-th wind speed sampling point, and n is preferably 10;

[0072] In step 2.3, i=1, 2,…N.

[0073] This embodiment also provides a range hood, Figure 2 , 3As shown, it includes a housing 1, a fan system 4 arranged inside the housing, an air inlet 11 connected to the inlet of the fan system is arranged on the upper front side of the housing, a filter 2 is arranged at the air inlet, a smoke baffle 3 is arranged at the air inlet on the front side of the housing, a filter detection device 5 for detecting the blockage state of the filter and a self-cleaning device 6 for automatically cleaning the filter are also arranged in the housing 1, and a display device 7 is arranged on the outside of the smoke baffle 3. The filter detection device 5 samples the above-mentioned range hood filter blockage detection method to detect the blockage of the filter, and the filter detection device 5 is connected to the display device 7 in communication. When the range hood starts the filter blockage detection function, the filter detection device will calculate the current moment of the range hood filter blockage area proportion X% and display it through the display device.

[0074] After the range hood filter is installed, the filter blockage detection function is first started, and the wind speed difference V0 measured at different working gears behind the range hood filter is saved in advance.

[0075] During the use of the range hood filter after installation, the filter blockage detection function is started in the delayed shutdown state, and the detection frequency is set as: initially once a week. When the blockage area of ​​the range hood filter accounts for X% and reaches the first preset threshold, the detection frequency is changed to once a day. The first preset threshold is 30% to 50%.

[0076] The filter detection device can be respectively provided with N wind speed sensors at N wind speed sampling points at different positions behind the range hood filter, and an electronic control device in communication with the N wind speed sensors, the electronic control device being used to calculate the blockage area proportion X% of the range hood filter at the current moment according to the wind speed values ​​collected by the N wind speed sensors. The electronic control device can be provided separately or integrated on the control circuit board of the range hood.

[0077] In this embodiment, the filter detection device 5 includes a wind speed sensor arranged at the rear side of the range hood filter and a driving device connected to the wind speed sensor 5 for driving the wind speed sensor 5 to and from N wind speed sampling points at different positions, and an electric control device connected to the wind speed sensor 51 for communication, and the electric control device is used to calculate the blockage area of ​​the range hood filter at the current moment according to the wind speed value collected by the wind speed sensor. The electric control device can be arranged separately or integrated on the control circuit board of the range hood. The above-mentioned driving device includes a base 52, a driving motor 53, a guide rail 54, a guide rail slider 55 and a bracket 56, wherein the base 52 is fixed on the housing 1, the driving motor 52 is fixed on the base 51, the guide rail 54 is also arranged on the base 51, the guide rail slider 55 is slidably arranged on the guide rail 54, the guide rail slider 54 is connected to the driving motor 52 through a transmission assembly, and can slide along the guide rail 54 under the drive of the driving motor 52, the bracket 56 is fixed on the guide rail slider 55, and the wind speed sensor 51 is fixed on the bracket 56. The transmission assembly includes a screw nut pair 57 and a coupling 58. The drive motor 52 is connected to the screw nut pair 57 through the coupling 58, and the guide rail slider 55 is fixedly connected to the nut slider of the screw nut pair 57. The screw length of the screw nut pair 57 is greater than the length of the filter, and the sliding stroke of the guide rail slider 55 is greater than the length of the filter. One end of the travel of the guide rail slider 55 on the guide rail 54 is directly opposite to the edge of one side of the filter, and the other end of the travel of the guide rail slider on the guide rail exceeds the edge of the other side of the filter by 50-100mm. The wind speed sensor moves back and forth between N wind speed sampling points, and the N wind speed sampling points are on the horizontal center line of the filter. After each detection of the filter detection device is completed, the wind speed sensor returns to the initial position and waits for the next detection. The initial position of the wind speed sensor avoids the air inlet and the entrance of the fan system, and the detection head of the wind speed sensor is blocked by the inner wall of the casing.

[0078] If the current blocked area of ​​the range hood filter accounts for X% and reaches a second preset threshold, the second preset threshold is 50% to 70%, such as 60%, the display device displays a red aperture to remind the user to replace and clean the filter. If the second preset threshold is not reached, a green aperture is displayed.

[0079] If the current blockage area of ​​the range hood filter accounts for X% and reaches the third preset threshold, the third preset threshold is 30% to 40%, such as 30%, the filter detection device adds a function to determine which side of the left and right sides of the filter is more seriously blocked, that is, calculate the average wind speed difference of the left N / 2 wind speed sampling points under different working gears and the average wind speed difference of the right N / 2 wind speed sampling points under different working gears, and determine which of the average wind speed difference on the left and the average wind speed difference on the right is greater, then the filter on this side is judged to be more seriously blocked than the other side. If the left filter is seriously blocked, and the current blockage area of ​​the range hood filter accounts for more than 50%, at this time, the display device displays the overall filter blockage ratio and flashes the red aperture + L for one minute. If the current blockage area of ​​the range hood filter does not exceed 50%, it displays the green aperture + L; the same is true for the right side; if the left and right sides are exactly equal, it does not flash. This function is displayed for one minute when the machine is turned on and off, which is used to remind the user to change the cooking position or swap the left and right positions of the filter, or choose to partially clean the filter.

[0080] In this embodiment, the self-cleaning device 6 is communicated with the filter detection device 5. When the filter detection device detects that the blockage area of ​​the range hood filter accounts for X% at the current moment and reaches a fourth preset threshold value, the fourth preset threshold value is 50% to 70%, the self-cleaning device starts and then automatically cleans the filter.

[0081] The self-cleaning device 6 comprises a nozzle 61 arranged on one side of the filter screen, and a plurality of spray ports are arranged along the length direction of the nozzle 61. The length direction of the nozzle is parallel to the width direction of the filter screen, and the length of the nozzle is greater than or equal to the width of the filter screen. The inlet of the nozzle is connected to a water supply device or a water steam supply device through a pipe 67, and the nozzle is connected to a reciprocating drive device, and the reciprocating drive device can drive the nozzle to move back and forth along the length direction of the filter screen. The water supply device comprises a water box and a water pump, or the water steam supply device comprises a water box, a water pump and a heater. The reciprocating drive device comprises a driving wheel 62 arranged on one side of the filter screen, the driving wheel 62 is connected to the output shaft of the cleaning motor 63 and is driven to rotate by the cleaning motor, a driven wheel 64 arranged on the other side of the filter screen, and a driving winding 65 connected to the nozzle 61 and wound around the driving wheel 62 and the driven wheel 64 at both ends. The reciprocating drive device also comprises a cleaning guide rail 66 arranged on both sides of the nozzle, and the two sides of the nozzle can slide in the cleaning guide rail.

[0082] The nozzle of the self-cleaning device sprays hot water or hot water steam through a water supply device or a water steam supply device, and uses the pressure and heat of hot water or hot water steam to achieve self-cleaning of the filter. Hot water or hot water steam can soften the oil stains, reduce the viscosity, and the pressure shock causes the oil stains to fall off. During the working process, when the filter detection device determines that the filter is seriously blocked, the self-cleaning device receives instructions to perform self-cleaning. The cleaning position is mainly concentrated in the position where the blockage is serious. For example, if the left side is seriously blocked, the cleaning device mainly reciprocates in the left area for cleaning, and performs cyclic reciprocating cleaning according to the percentage of blockage. When the cleaning of the serious side is completed, the filter is cleaned as a whole. The cleaning number is at least 2 cycles, and it is reset after the cleaning is completed.

[0083] The self-cleaning device 6 is installed on the smoke baffle 3. The overall structure size is small. After the smoke baffle is closed, it can be avoided by the corresponding position profile and other structures to avoid interference. During the cleaning process, the smoke baffle is closed, the self-cleaning device is running, and the fan system is running to exhaust. The water supply device or the water steam supply device can be installed on the top or inside the range hood casing. When the self-cleaning device is running, the cleaning motor rotates forward and reverse according to the instructions. When rotating forward, the driving wheel will roll up the driving winding, pull the nozzle to move to the right, and the driving winding at the driven wheel will unfold; during the reversal of the cleaning motor, the driving wheel reverses, and the driven wheel also reverses to roll up the driving winding, so that the nozzle moves in the opposite direction, thereby realizing the reciprocating motion of the nozzle.

[0084] There are jet ports spaced at intervals on the surface of the nozzle. The middle hole is an inclined hole, which is slanted downward. When hot water or hot water steam is ejected, a downward shear force is generated, which promotes the removal of oil stains. At the same time, the small holes on the left and right sides are straight holes, but have a certain angle with the plane, so that the steam impact force generated produces a left and right shear force, which promotes the removal of oil stains and improves the cleaning effect. During the cleaning process, the steam will first soften the oil stains, and then use the steam impact force to remove the oil stains. At the same time, the fan is running, sucking the water vapor into the volute impeller. When the water content of the water vapor is high, the impeller and the water vapor collide with each other, which also has a certain cleaning effect on the impeller.

Claims

1. A range hood filter blockage detection method, characterized in that: Use the following steps to obtain the range hood filter blockage status: Step 1: After the range hood filter is installed, start the filter blockage detection function and measure the wind speed difference V0 at different working gears behind the range hood filter, including: Step 1.1, first make the range hood stably run at the first working gear, and then obtain the wind speed value behind the filter of the range hood at this time, which is recorded as V11; Step 1.2, switching the working gear of the range hood to make the range hood stably run at the second working gear, and then obtaining the wind speed value behind the filter of the range hood at this time, recorded as V12; wherein the second working gear is different from the first working gear; Step 1.3, calculate the wind speed difference V0=|V11-V12| at different working gears behind the range hood filter; Step 2: During the use of the range hood filter after installation, if the filter blockage detection function is started again, the blockage area ratio of the range hood filter at the current moment is obtained, which specifically includes: Step 2.1, first make the range hood stably operate at the first working gear, and then obtain the wind speed value behind the filter of the range hood at this time, which is recorded as V21; Step 2.2, switching the working gear of the range hood to make the range hood stably run at the second working gear, and then obtaining the wind speed value behind the filter of the range hood at this time, which is recorded as V22; wherein the second working gear is different from the first working gear; Step 2.3, calculate the wind speed difference V1=|V21-V22| at different working gears behind the range hood filter at the current moment; Step 2.4, calculate the current moment the range hood filter blockage area accounts for X%: X%=100%-Y%, where Y%=V0 / V1; The rear side of the range hood filter is provided with N wind speed sampling points at different positions; The V11 measured in step 1.1 includes the wind speed values ​​of the N different wind speed sampling points, and V11=V 11i , where i represents the sampling position, i=1, 2, ... N, N is a natural number greater than or equal to 2; V21 measured in step 1.2 includes the wind speed values ​​of the N different wind speed sampling points, and V12 = V 12i , where i represents the sampling position, i=1, 2, ... N, N is a natural number greater than or equal to 2; The V21 measured in step 2.1 includes the wind speed values ​​of the N different wind speed sampling points, and V21=V 21i , where i represents the sampling position, i=1, 2, ... N, N is a natural number greater than or equal to 2; V22 measured in step 2.2 includes the wind speed values ​​of the N different wind speed sampling points, and V22 = V 22i , where i represents the sampling position, i=1, 2, ... N, N is a natural number greater than or equal to 2; 2. The range hood filter clogging detection method according to claim 1, characterized in that: The V 11i 、V 12i 、V 21i 、V 22i They are all the average values ​​of n samples, where n is a natural number greater than or equal to 2.

3. A range hood, comprising a housing, a fan system arranged inside the housing, an air inlet connected to an inlet of the fan system provided on the housing, a filter provided at the air inlet, characterized in that: The housing is also provided with a filter detection device for detecting the clogging state of the filter, the filter detection device includes a wind speed detection device arranged at the rear side of the filter, and the filter detection device detects the clogging state of the filter by adopting the range hood filter clogging detection method as claimed in claim 1; The housing is provided with a display device, and the filter detection device is in communication connection with the display device. When the range hood starts the filter blockage detection function, the filter detection device displays the calculated filter blockage area ratio X% of the range hood at the current moment through the display device; During the use of the range hood filter after installation, the detection frequency of the filter blockage detection function is set to: initially once a week, when the blockage area of ​​the range hood filter accounts for X% and reaches a first preset threshold, the detection frequency is changed to once a day, and the first preset threshold is 30% to 50%.

4. The range hood according to claim 3, characterized in that: During the use of the range hood filter after installation, the filter clogging detection function is activated in the delayed shutdown state of the range hood.

5. The range hood according to claim 3, characterized in that: The first working gear is a strong gear, and the second working gear is a weak gear.

6. The range hood according to claim 3, 4 or 5, characterized in that: The filter detection device includes N wind speed sensors respectively arranged at N wind speed sampling points at different positions on the rear side of the range hood filter, and an electronic control device communicatively connected to the N wind speed sensors, wherein the electronic control device is used to calculate the blockage area of ​​the range hood filter accounting for X% at the current moment according to the wind speed values ​​collected by the N wind speed sensors.

7. The range hood according to claim 3, 4 or 5, characterized in that: The filter detection device includes a wind speed sensor arranged on the rear side of the range hood filter, a driving device connected to the wind speed sensor for driving the wind speed sensor to and from N wind speed sampling points at different positions, and an electronic control device communicatively connected to the wind speed sensor, the electronic control device being used to calculate the blockage area of ​​the range hood filter accounting for X% at the current moment based on the wind speed value collected by the wind speed sensor.

8. The range hood according to claim 7, characterized in that: The driving device includes a base, a driving motor, a guide rail, a guide rail slider and a bracket. The base is fixed on the casing, the driving motor is fixed on the base, the guide rail is also arranged on the base, the guide rail slider is slidably set on the guide rail, the guide rail slider is connected to the driving motor through a transmission assembly and can slide along the guide rail when driven by the driving motor, the bracket is fixed on the guide rail slider, and the wind speed sensor is fixed on the bracket.

9. The range hood according to claim 8, characterized in that: The transmission assembly comprises a screw nut pair and a coupling, the driving motor is connected to the screw nut pair through the coupling, and the guide rail slider is fixedly connected to the nut slider of the screw nut pair.

10. The range hood according to claim 9, characterized in that: The screw length of the screw nut pair is greater than the length of the filter screen, and the sliding stroke of the guide rail slider is greater than the length of the filter screen.

11. The range hood according to claim 10, characterized in that: One end of the travel of the guide rail slider on the guide rail is directly opposite to the edge of one side of the filter screen, and the other end of the travel of the guide rail slider on the guide rail exceeds the edge of the other side of the filter screen by 50-100mm.

12. The range hood according to claim 7, characterized in that: The wind speed sensor moves back and forth between N wind speed sampling points, and the N wind speed sampling points are located on the horizontal center line of the filter.

13. The range hood according to claim 7, characterized in that: After each detection of the filter detection device is completed, the wind speed sensor returns to the initial position and waits for the next detection. The initial position of the wind speed sensor avoids the air inlet and the entrance of the fan system, and the detection head of the wind speed sensor is blocked by the inner wall of the casing.

14. The range hood according to claim 3, characterized in that: If the current blocked area of ​​the range hood filter accounts for X% and reaches a second preset threshold value, which is 50% to 70%, the display device displays a red aperture to remind the user to replace and clean the filter.

15. The range hood according to claim 3, characterized in that: If the blockage area of ​​the range hood filter accounts for X% at the current moment and reaches the third preset threshold, the third preset threshold is 30% to 40%, the filter detection device adds a function to determine which side of the left or right side of the filter is more seriously clogged, namely: calculate the average wind speed difference of the N / 2 wind speed sampling points on the left side under different working gears and the average wind speed difference of the N / 2 wind speed sampling points on the right side under different working gears, and determine which one is larger between the average wind speed difference on the left and the average wind speed difference on the right, then it is determined that the filter on this side is more seriously clogged than the filter on the other side.

16. The range hood according to claim 3, characterized in that: Also included is a self-cleaning device for automatically cleaning the filter screen.

17. The range hood according to claim 16, characterized in that: The self-cleaning device is communicatively connected with the filter detection device. When the filter detection device detects that the blockage area of ​​the range hood filter accounts for X% at the current moment and reaches a fourth preset threshold value, which is 50% to 70%, the self-cleaning device starts and then automatically cleans the filter.

18. The range hood according to claim 17, characterized in that: The self-cleaning device includes a nozzle arranged on one side of the filter, and the nozzle is provided with a plurality of injection ports arranged along its length direction. The length direction of the nozzle is parallel to the width direction of the filter, and the length of the nozzle is greater than or equal to the width of the filter. The inlet of the nozzle is connected to a water supply device or a water steam supply device through a pipeline, and the nozzle is connected to a reciprocating drive device, which can drive the nozzle to reciprocate along the length direction of the filter.

19. The range hood according to claim 18, characterized in that: The water supply device includes a water box and a water pump, or the water steam supply device includes a water box, a water pump and a heater.

20. The range hood according to claim 18, characterized in that: The reciprocating drive device includes a driving wheel arranged on one side of the filter, the driving wheel is connected to the output shaft of the cleaning motor and is driven to rotate by the cleaning motor, and a driven wheel arranged on the other side of the filter is connected to the nozzle and has driving windings at both ends respectively wound around the driving wheel and the driven wheel.

21. The range hood according to claim 20, characterized in that: The reciprocating drive device also includes cleaning guide rails arranged on both sides of the nozzle, and the two sides of the nozzle can slide in the cleaning guide rails.

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