Air quality detection device and range hood

Abstract

The utility model discloses an air quality detection device and a range hood, the air quality detection device comprises a controller, an air quality sensor and a voltage-adjustable driving board, the air quality sensor is in electric signal connection with the voltage-adjustable driving board, and the voltage-adjustable driving board is in electric signal connection with the controller. According to the air quality detection device, the multi-gas response characteristic of the sensor is actively excited through the controller and the voltage-adjustable driving plate, the detection limitation of a single-function sensor is broken through, and accurate identification of different pollutant gases is realized, so that the air quality detection device can be used in a scene in which the pollutant gases frequently change; meanwhile, the delay defect of passive detection is avoided through active voltage excitation, and the detection speed is remarkably increased; besides, the range hood provided with the air quality detection device can accurately identify various pollutant gases, and actively adopts corresponding control strategies at the initial stage of pollutant concentration accumulation, so that the response speed is relatively high, intelligent net catching of different dynamic particles such as oil smoke is effectively realized, and active protection of kitchen air is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to oil fume detection and purification device especially air quality detection device and range hood. BACKGROUND

[0002] The influence of kitchen air quality on human health is increasingly valued. As the core equipment for removing kitchen oil fume, the function of range hood has been expanded from simply sucking and exhausting oil fume to integrating air monitoring function. In the prior art, some range hoods integrate air quality monitoring modules for detecting the concentration of pollutants such as TVOC (total volatile organic compounds) and PM2.5 in the kitchen environment, and automatically adjusting the operating state of the range hood according to the detection results to improve the kitchen environment quality. However, the existing air monitoring scheme of range hood still has the following technical defects:

[0003] Firstly, in terms of pollutant identification capability, the existing air quality detection scheme generally has the problems of insufficient identification accuracy and inability to trace the source. Although the common TVOC sensor can detect the total amount of volatile organic compounds in the environment, it cannot distinguish from the detection results whether the current main pollutant is oil fume, formaldehyde, or gas leakage, etc. Moreover, in some actual scenarios, such as cooking scenarios, the type of main pollutant will change with different cooking scenarios. Since the single-function sensor has high sensitivity to only one type of pollutant, if the type of main pollutant in the air changes, it cannot identify the new main pollutant or the change. Similarly, single-function PM2.5 or other gas sensors also have similar limitations. This leads to the user being unable to obtain accurate pollutant type information and makes it difficult to achieve targeted fine management of air quality.

[0004] Secondly, even if a sensor or sensor array that can respond to multiple gases is used, the back-end identification method usually relies on pre-set fixed response patterns or threshold comparison. This method requires the concentration of the gas to be detected to reach a certain level or to present a "fingerprint" feature that is significantly different from other gases in order to effectively identify. In the complex environment of the kitchen, multiple pollutant gases (such as oil fume, aldehyde, and gas) often coexist, and their combined effects can easily cause the response patterns of the sensors to overlap or distort, significantly reducing the identification accuracy. At the same time, this identification mechanism that relies on high concentration or obvious features also leads to a lag in system response, making the control action of the range hood not timely enough, affecting the user experience and health protection effect.

[0005] Finally, in terms of cost and practicality, existing solutions have contradictions and limitations. Sensors or arrays with certain multi-gas recognition capabilities are usually expensive. More importantly, in the harsh kitchen environment with heavy smoke and large temperature and humidity fluctuations, sensors are easily affected by factors such as oil coverage and high-temperature drift, resulting in a shortened service life and reduced detection accuracy. Frequent maintenance or replacement is required, increasing user costs. Although low-cost single-function sensors may have more cost advantages, their fundamental defects of being single-function and unable to be used in scenarios where pollutants are constantly changing still exist. The above makes it difficult for existing solutions to meet the dual needs of accurate monitoring and active protection. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to provide an air quality detection device that can be used to detect different pollutant gases in response to the above-mentioned existing technical status.

[0007] The second technical problem to be solved by the present invention is to provide a range hood adopting the air quality detection device in view of the above-mentioned existing technical status.

[0008] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: an air quality detection device, including a controller, an air quality sensor and a voltage-adjustable driving board, the air quality sensor is electrically connected to the voltage-adjustable driving board, and the voltage-adjustable driving board is electrically connected to the controller; the controller is used to control the voltage-adjustable driving board to load different input voltages on the air quality sensor; the air quality sensor has different resistance response characteristics to different types of gases.

[0009] With this setting, the controller drives the voltage-adjustable driver board to dynamically load the input voltage to the air quality sensor, so that under different input voltages, the air quality sensor can present corresponding response characteristics based on the gas type, that is, a dynamic scanning method is used to trigger the response characteristics. On the one hand, the air sensor can still detect the corresponding pollutant gas in the scenario where the pollutants change, and on the other hand, it can realize the active identification and classification of the gas to be detected, thereby improving the detection speed.

[0010] Preferably, the air quality sensor adopts a SnO2-based semiconductor MOS sensor to adapt to the dynamic voltage excitation mode.

[0011] Further preferably, the air quality detection device further includes a signal processor, the air quality sensor being electrically connected to the signal processor, and the output signal of the air quality sensor being processed by the signal processor and then read by the controller. With this arrangement, the signal processor can process the output signal of the air quality sensor using various methods such as filtering and noise reduction, thereby making the signal read by the controller more accurate.

[0012] Further preferably, the air quality detection device further includes a temperature sensor electrically connected to the controller via a signal processor. The controller obtains the current temperature via the temperature sensor and the signal processor and converts the resistance measured at the current temperature into resistance at a standard temperature. This configuration eliminates the effects of temperature drift on classification accuracy by standardizing the varying temperatures under the detection environment to the temperature under the calibration environment, resulting in more accurate gas classification and identification.

[0013] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a range hood, equipped with the air quality detection device, which includes an upper box body and a lower box body installed at the bottom of the upper box body, a range hood fan is installed inside the upper box body, the lower box body has an air inlet, and the air quality sensor is installed on the outer wall of the lower box body.

[0014] Further preferably, a mounting cavity is provided on the left or right outer wall of the lower housing, with the air quality sensor and temperature sensor located within the mounting cavity. Placing the air quality sensor and temperature sensor on a sidewall outside the oil smoke rising path can prevent the sensors from being susceptible to oil coverage and high-temperature drift during long-term use, thereby extending their service life.

[0015] An oil-proof device is installed at the opening of the installation cavity. The oil-proof device can prevent oil smoke from contaminating the sensor, which is beneficial to improving the detection accuracy of the sensor and extending the service life of the sensor.

[0016] Further preferably, the oil-proof device is an oil-proof grille, and the oil-proof grille is provided with an airflow acceleration channel, thereby improving gas diffusion efficiency.

[0017] Preferably, the controller controls the working gear or speed of the range fumes exhaust fan in real time according to the identified gas type.

[0018] Compared with existing designs, the advantages of the present invention are: the air quality detection device actively stimulates the multi-gas response characteristics of the air quality sensor through a controller and a voltage-adjustable driver board, breaks through the detection limitations of single-function sensors, and realizes accurate identification of different pollutant gases, so that it can be used in scenarios where pollutant gases often change; at the same time, active voltage excitation avoids the delay defects of passive detection and significantly improves the detection speed; in addition, the range hood equipped with the air quality detection device can accurately identify a variety of pollutant gases, and actively adopt corresponding control strategies at the early stage of pollutant concentration accumulation, with a fast response speed, effectively realizing the intelligent capture of different dynamic particles such as oil smoke, meeting the user's requirements for kitchen air quality monitoring, thereby breaking through the shortcomings of passive smoke removal of traditional range hoods and realizing active protection of kitchen air. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of a module of an air quality detection device according to an embodiment of the present utility model;

[0020] Figure 2 This is a schematic diagram of the installation structure of the range hood according to an embodiment of the present utility model;

[0021] Figure 3 This is a schematic diagram of a usage scenario of a range hood according to an embodiment of the utility model;

[0022] Figure 4 This is a schematic diagram of the sensor installation structure of an embodiment of the present utility model;

[0023] Figure 5 A schematic diagram of a gas detection system according to an embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the control flow of an embodiment of the present utility model. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 As shown, an air quality detection device of this embodiment includes a controller 1, an air quality sensor 2, a voltage-adjustable driver board 3, and a signal processor 4. The air quality sensor 2 is electrically connected to the voltage-adjustable driver board 3 and the signal processor 4, respectively. The voltage-adjustable driver board 3 and the signal processor 4 are both electrically connected to the controller 1. The controller 1 applies different input voltages to the air quality sensor 2 through the voltage-adjustable driver board 3. The air quality sensor 2 has different resistance response characteristics for different types of gases. In this way, the controller 1 actively and dynamically applies input voltages to the air quality sensor 2, so that the air quality sensor 2 exhibits different response characteristics under different input voltages, that is, a dynamic scanning method is used to trigger the response characteristics. This allows the air sensor to detect a variety of pollutant gases to be detected on the one hand, and on the other hand, it can realize active identification and classification of the gases to be detected.

[0027] The air quality detection device also includes a temperature sensor 5, which is electrically connected to the controller 1 via a signal processor 4. The controller 1 uses the temperature sensor 5 and the signal processor 4 to obtain the current temperature and converts the resistance measured at the current temperature into the resistance at the standard temperature. By standardizing the varying temperatures under the detection environment to the temperature under the calibration environment, the effects of temperature drift on classification accuracy are eliminated, resulting in more accurate gas classification and identification.

[0028] like Figure 2-4As shown, another embodiment of the range hood is equipped with the air quality detection device of the above embodiment, which includes an upper box body 6 and a lower box body 7 installed at the bottom of the upper box body 6. The upper box body 6 is equipped with a range hood fan 8, and the lower box body 7 has an air inlet 71. A mounting cavity 72 is provided on the left or right outer wall of the lower box body 7. The air quality sensor 2 and the temperature sensor 5 are installed in the mounting cavity 72. An oil-proof device is installed at the opening of the mounting cavity 72. The oil-proof device is a common oil-proof net, or a Figure 4 The oil-proof grille 9 shown in . In this embodiment, the air quality sensor 2 adopts a SnO2-based semiconductor MOS sensor. The MOS sensor has different response characteristics for different types of gases. Specifically, under the drive of the characteristic voltage point, it has different resistance response curves for different types of gases. The temperature sensor 5 is installed in a patch type with an accuracy of ±0.5°C. The temperature sensor 5 is used for temperature compensation and converts the resistance measured at the current temperature into the resistance at the standard temperature. The aperture or slit width of the oil-proof grille 9 is 0.5-3mm, which can block large oil particles, avoid sensor contamination, improve detection accuracy and extend the service life of the sensor. In addition, the oil-proof grille 9 can also adopt a Venturi-like gas acceleration channel 91 structure with a large outside and a small inside to improve the response speed.

[0029] like Figure 5 As shown, the voltage-adjustable drive board 3 is electrically connected to the air quality sensor 2, and the air quality sensor 2 and temperature sensor 5 are both electrically connected to the signal processor 4. The voltage-adjustable drive board 3 and the signal processor 4 are both electrically connected to the controller 1. The output signals of the air quality sensor 2 and the temperature sensor 5 are processed by the signal processor 4 and then read by the controller 1. The controller 1 then classifies the gas to be detected based on the read signals and controls the operating gear or speed of the range hood fan 8 accordingly according to the type of gas pollutant.

[0030] The range hood of this embodiment further includes a control method, which constructs a characteristic vector and uses the characteristic vector to match the gas to be detected to obtain the most matching corresponding gas type.

[0031] like Figure 6 As shown, the control method of the range hood of this embodiment includes the following steps:

[0032] S1, system startup;

[0033] S2, air quality sensor 2 preheating;

[0034] S3, initialize voltage scan;

[0035] S4, dynamically applying voltage and collecting resistance data corresponding to the characteristic voltage point of the gas to be identified;

[0036] S5, the controller 1 reads the temperature detected by the temperature sensor 5;

[0037] S6, performing temperature compensation on the temperature detected in step S5, and calculating a calibration resistance value;

[0038] S7, calculating the characteristic spectrum value of each corresponding characteristic voltage point;

[0039] S8-1, calculate the eigenvector;

[0040] S8-2, calculate the vector space distance;

[0041] S8-3. Find the minimum distance in the vector space. The gas corresponding to the minimum distance is the main pollutant type.

[0042] S9. Calculate the concentration of main pollutant gases;

[0043] S10, determining whether the gas concentration is greater than a threshold;

[0044] If yes, proceed to step S11;

[0045] If not, return to step S3;

[0046] S11 . According to the relationship between the concentration of different pollutant gases and the threshold values, the controller 1 adjusts the working gear or the speed of the range fumes exhaust fan 8 accordingly.

[0047] Step S4: One of the dynamic voltage loading methods is to load the voltage point by using a dynamic step voltage method. , and collect the corresponding resistance of the gas to be identified at the loading voltage point data; among which, ,and As an example, if the starting voltage is 0.8 V, the step voltage ∆V = 0.1 V until the voltage reaches 5 V. Of course, the starting voltage and step voltage are not limited to the above example values.

[0048] Of course, as another method, step S4 can also be used to dynamically load multiple fixed characteristic voltage points For example, according to the common gas types in the kitchen, this embodiment selects 5 characteristic voltage points 、 Loading, each characteristic voltage point dwell time can be set to 200ms. Other values ​​are also possible. The above are just examples and will not be described in detail here.

[0049] The temperature compensation formula in step S6 is as follows: ,in, is the corresponding resistance value after temperature compensation calibration under the applied voltage, To calibrate the standard temperature, The current measured temperature.

[0050] In step S7, the characteristic spectrum value of each characteristic voltage point Expressed as: .

[0051] In step S8-1, the feature vector is calculated and constructed ;

[0052] In step S8-2, according to the classification decision Computing vector space distances ,in, Indicates the Gas standard vectors are obtained by placing the air quality sensor in different standard gases and collecting them according to the aforementioned voltage pressure, and ;

[0053] In step S8-3, the minimum vector space distance value is found among the calculated multiple vector space distance values, and the gas type corresponding to the minimum vector space distance value is the main pollutant type.

[0054] In step S9, according to the determined main pollutant type, the characteristic response voltage corresponding to the main pollutant is loaded, the real-time resistance and real-time temperature are collected, and the main pollutant concentration is calculated. , ,in,

[0055] is the material constant, is the absolute temperature, is the voltage sensitivity coefficient, is the characteristic response voltage corresponding to the main pollutant, is the gas sensitivity, Load characteristic response voltage The real-time temperature collected later, Load characteristic response voltage The real-time resistance collected later.

[0056] Exemplarily, a corresponding relationship is established between the main pollutants and the characteristic response voltages, as follows:

[0057] When the main pollutant is the pollutant generated by the volatilization of oil deposition, the recommended characteristic response voltage is 1.8V;

[0058] When the main pollutant is formaldehyde, the recommended characteristic response voltage is 2.3V;

[0059] When the main pollutant is frying fume, the recommended characteristic response voltage is 3.0V;

[0060] When the main pollutant is pollutant generated by barbecue, the recommended characteristic response voltage is 3.8V;

[0061] When the main pollutants are methane and propane produced by gas leakage, the recommended characteristic response voltage is 4.5V.

[0062] Of course, the above main pollutants and their corresponding recommended characteristic response voltages are only examples, and the actual main pollutant types and their recommended characteristic response voltages are not limited thereto.

[0063] In step S11, the controller 4 adjusts the working gear or speed of the range hood fan 2 according to the determined main pollutant type and the comparison result between the concentration and the threshold value. The threshold values ​​of various pollutants can be set according to experiments and health protection:

[0064] When the main pollutants are frying fumes or pollutants generated by barbecue, and >Threshold, the control strategy is: fan high-speed or boost mode;

[0065] When the main pollutants are methane and propane from gas leaks, and >Threshold value, the control strategy is: remind doors and windows to open + fan medium gear active exhaust;

[0066] When the main pollutant is formaldehyde, and >Threshold, the control strategy is: linkage with fresh air equipment + low-speed ventilation of fans;

[0067] When the main pollutants are pollutants generated by the volatilization of deposited oil, and >Threshold, the control strategy is: low-speed ventilation of the fan + reminder to clean the deposited oil.

[0068] The fan gear and boost mode are explained as follows:

[0069] Low gear: The speed is relatively low, typically within 500RPM, and it is mainly used for low-noise ventilation; Mid-range: The speed is moderate, typically 500-1000RPM, and it is mainly used for non-oil smoke cooking ventilation, balancing noise and ventilation efficiency; High-end: The speed is relatively high, typically 1000-1500RPM, and it is mainly used for frying, stir-frying and other oil smoke cooking suction and exhaust, and tends to absorb oil smoke; Boost mode: The speed is high, typically above 1500RPM, and it is mainly used for short-term sudden large oil smoke during frying, stir-frying and other cooking processes under back pressure resistance such as connecting to a public flue (such as the moment the food is put into the pot, during the stir-frying process), sacrificing noise and increasing the speed to improve the oil smoke exhaust capacity.

[0070] In the specification and claims of the present invention, directional terms such as "front," "back," "up," "down," "left," "right," "side," "top," and "bottom" are used to describe various exemplary structural parts and components of the present invention. However, these terms are used herein for convenience of description only and are based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different orientations, these directional terms are intended for illustrative purposes only and should not be construed as limiting. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0071] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art could make numerous variations and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application.

Claims

1. An air quality detection device, comprising a controller (1) and an air quality sensor (2), characterized in that: It also includes a voltage-adjustable drive board (3), the air quality sensor (2) is electrically connected to the voltage-adjustable drive board (3), and the voltage-adjustable drive board (3) is electrically connected to the controller (1); the controller (1) is used to control the voltage-adjustable drive board (3) to load different input voltages on the air quality sensor (2); and the air quality sensor (2) has different resistance response characteristics to different types of gases.

2. The air quality detection device according to claim 1, characterized in that: The air quality sensor (2) adopts a SnO2-based semiconductor MOS sensor.

3. The air quality detection device according to claim 1, characterized in that: A signal processor (4) is also included. The air quality sensor (2) is electrically connected to the signal processor (4). The output signal of the air quality sensor is processed by the signal processor and then read by the controller.

4. The air quality detection device according to any one of claims 1 to 3, characterized in that: The air quality detection device further comprises a temperature sensor (5), wherein the temperature sensor (5) is electrically connected to the controller (1) via a signal processor (4); the controller (1) obtains the current temperature via the temperature sensor (5) and the signal processor (4), and converts the resistance measured at the current temperature into the resistance at a standard temperature.

5. A range hood, comprising an upper box (6) and a lower box (7) mounted at the bottom of the upper box (6), wherein a range hood fan (8) is mounted inside the upper box (6), and the lower box (7) has an air inlet (71), characterized in that: The range hood is installed with the air quality detection device according to any one of claims 1 to 4.

6. The range hood according to claim 5, characterized in that: The air quality sensor (2) of the air quality detection device and the temperature sensor (5) electrically connected to the controller (1) are both mounted on the outer side wall of the lower box (7).

7. The range hood according to claim 6, characterized in that: A mounting cavity (72) is provided on the left outer side wall or the right outer side wall of the lower box (7), and the air quality sensor (2) and the temperature sensor (5) are located in the mounting cavity (72).

8. The range hood according to claim 7, characterized in that: An oil-proof device is installed at the opening of the installation cavity (72).

9. The range hood according to claim 8, characterized in that: The oil-proof device is an oil-proof grille (9), and the oil-proof grille (9) is provided with an airflow acceleration channel (91).

10. The range hood according to any one of claims 5 to 9, characterized in that: The controller (1) controls the operating gear or rotation speed of the range fumes exhaust fan (8) according to the identified gas type.

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