Range hood

Abstract

The range hood comprises a machine body, a fan system is arranged in the machine body, an inlet is formed in the machine body, and a smoke barrier is connected to the inlet of the machine body, and is characterized in that the lower surface of the smoke barrier is divided into a plurality of areas, and a thermoelectric film layer capable of being independently controlled is attached to the lower surface of each area; the thermoelectric thin film layer of each area is electrically connected with the MCU controller, and the MCU controller judges whether there is accumulated water in the area or not by collecting voltage signals output by the signal output ends of the thermoelectric thin film layers of different areas due to temperature difference generated by heat dissipation of condensed accumulated water. And then the accumulated water coverage rate of the lower surface of the smoke barrier is calculated according to the accumulated water conditions of the different areas, and the gears of the fan system are adjusted according to the accumulated water coverage rate of the lower surface of the smoke barrier. Compared with the prior art, whether water drops are condensed on the surface of the smoke barrier can be detected, so that the gears of the fan system are dynamically adjusted and controlled, and the use experience of a user is improved.

Description

Technical Field

[0001] The invention relates to a range hood. Background Art

[0002] Range hoods are essential appliances for daily cooking, and range hoods with smoke dampers have become increasingly popular in recent years. However, cooking gases typically contain both oil smoke and water vapor. This is especially true in steaming mode, where high levels of water vapor easily condense on the lower surface of the smoke damper. Steaming is more prone to water vapor formation than frying. However, in steaming mode, users often choose a medium or low fan setting due to concerns about fume concentration and noise. Range hoods are installed above cooking stoves and pots, and rising smoke and water vapor easily condense on the range hood's smoke damper. These droplets can easily drip into the pot, impacting the user experience, or condense on the damper or panel, hindering user interaction with buttons. In steaming mode, even when the user increases the air volume, water vapor is directed toward the air inlet by the higher lateral velocity, reducing the amount of water vapor passing near the lower surface of the damper. This can initially reduce the formation of water droplets on the damper's lower surface. However, when water vapor condensation accumulates significantly, increasing the air volume will not resolve the condensation droplet problem. Generally speaking, traditional range hoods lack the ability to monitor the condensation of water vapor generated during cooking in real time. This results in: 1. Water droplets easily forming on the glass panel, which can contaminate food; 2. Existing humidity sensors have a slow response speed (>5 seconds) and can only detect a single point; 3. They are unable to distinguish the location and severity of water accumulation, resulting in a crude control strategy. Therefore, the existing technology needs further improvement. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a range hood that can detect whether there is water droplet condensation on the surface of the smoke baffle and adjust the gear position of the fan system according to the water accumulation situation in response to the above-mentioned prior art.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a range hood, comprising a body, a fan system is arranged in the body, an inlet is arranged on the body, and a smoke shield is connected to the inlet of the body, characterized in that: the lower surface of the smoke shield is divided into multiple areas, the lower surface of each area is adhered to a thermoelectric film layer that can be independently controlled, the thermoelectric film layer of each area is electrically connected to a signal output end, and the signal output end of the thermoelectric film layer of each area is electrically connected to an MCU controller. The MCU controller collects the temperature difference caused by the heat dissipation of condensed water in the thermoelectric film layers in different areas, thereby causing the voltage signal output from its signal output end, thereby determining whether there is water accumulation in the area, and then calculates the water coverage rate of the lower surface of the smoke shield according to the water accumulation situation in different areas, and then adjusts the gear of the fan system according to the water coverage rate of the lower surface of the smoke shield.

[0005] As an improvement, after the MCU controller collects the temperature difference caused by the heat dissipation of condensed water in the thermoelectric thin film layer in a certain area, resulting in the voltage signal output from its signal output end, the voltage signal is amplified by an amplifier circuit, and then filtered by a band-pass filter circuit, retaining only the voltage signal caused by water droplet condensation or dripping, filtering out voltage signals caused by other reasons, marking the voltage signal after filtering by the band-pass filter circuit, and marking the area where the voltage signal still exists after filtering by the band-pass filter circuit as a water accumulation area.

[0006] A further improvement involves applying a heating wire layer to the outer surface of each thermoelectric film layer, arranged in a zigzag S-shaped pattern. Each heating wire layer is also electrically connected to the MCU controller. When the MCU detects that the water coverage rate on the smoke shield's lower surface exceeds 20%, the heating wire layer in the corresponding waterlogged area is activated for electrical heating. The zigzag S-shaped pattern of the heating wires in this heating wire layer allows them to perform more than just heating and dehumidifying when high-humidity water condenses.

[0007] During the actual control process, the MCU controller can also start the electric heating of the heating wire layer in the corresponding area with water accumulation only when it is counted that the water coverage rate η on the lower surface of the smoke shield is greater than 20%, and the increase in the water coverage rate η per unit time is greater than 2%.

[0008] As a further improvement, an electric control board is provided in the machine body, the MCU controller is integrated in the electric control board of the machine body, and the fan system is electrically connected to the electric control board.

[0009] As a further improvement, the outer surface of the heating wire layer in each area is also coated with an insulating layer or a hydrophobic coating.

[0010] Preferably, the lower surface of the smoke baffle is divided into 3 rows and 6 columns, totaling 18 areas.

[0011] Further improvement, when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield is less than 5%, the speed of the fan system is adjusted to 800rpm; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies 5%≤η<20%, ​​the speed of the fan system is adjusted to 1000rpm; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies 20%≤η<40%, the speed of the fan system is adjusted to 1500rpm, the heating wire layer in the corresponding area with water accumulation is started for electric heating, and the heating power of the heating wire layer in the corresponding area with water accumulation is adjusted to 200W; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies η≥40%, the speed of the fan system is adjusted to 2000rpm, the heating wire layer in the corresponding area with water accumulation is started for electric heating, and the heating power of the heating wire layer in the corresponding area with water accumulation is adjusted to 500W.

[0012] Compared with the existing technology, the advantages of the present invention are: by dividing the lower surface of the smoke shield into areas and affixing thermoelectric film layers to the surfaces of different areas, it is equivalent to affixing a special "temperature-voltage conversion sticker" on the lower surface of the smoke shield. By utilizing the Seebeck effect generated by the thermoelectric film, the heat generated when the water droplets condense will be captured by the thermoelectric film and immediately converted into an electrical signal, so as to determine whether there is water accumulation in the area, and then calculate the water accumulation coverage rate of the lower surface of the smoke shield according to the water accumulation conditions in different areas, and then adjust the gear of the fan system according to the water accumulation coverage rate of the lower surface of the smoke shield, thereby realizing the multi-functional application of the sensor, improving the scene adaptability and user cooking comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the oil fume suction structure in an embodiment of the present invention.

[0014] Figure 2 Schematic diagram of the area division of the lower surface of the smoke shield in an embodiment of the present invention.

[0015] Figure 3 It is a partial cross-sectional view of a certain area of ​​the smoke shield in an embodiment of the present invention.

[0016] Figure 4 This is a schematic diagram of the structure of the thermoelectric film layer and the heating wire layer on a certain area of ​​the surface of the smoke shield in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0018] This embodiment provides a range hood, see Figure 1 As shown, it includes a body 1, a fan system is provided in the body 1, an inlet 11 is provided on the body, a smoke baffle 2 is connected to the inlet of the body, an electric control board is provided in the body 1, and an MCU controller is integrated in the electric control board.

[0019] The lower surface of the smoke baffle 2 is divided into 3 rows and 6 columns, a total of 18 areas of equal area, see Figure 2 As shown; the lower surface of each area is adhered to a thermoelectric film layer 21 that can be independently controlled, the outer surface of the thermoelectric film layer 21 is adhered to a heating wire layer 22, and the outer surface of the heating wire layer 22 is coated with an insulating layer or a hydrophobic coating 23, see Figure 3 As shown, the thermoelectric film layer 21 uses a bismuth telluride thermoelectric film array layer. Bi2Te3 thermoelectric film is a key material that can convert temperature changes into voltage, similar to a thermometer, but with a response time 1000 times faster. The heating wire layer 22 uses nickel-chromium alloy heating wires, and the insulating layer or hydrophobic coating 23 can provide insulation and enhance hydrophobicity.

[0020] The thermoelectric film layer 21 in each area is electrically connected to a signal output end, and the signal output end of the thermoelectric film layer in each area is electrically connected to the MCU controller. The MCU controller collects the temperature difference caused by the heat dissipation of condensed water in the thermoelectric film layers in different areas, resulting in the voltage signal output from its signal output end, so as to determine whether there is water accumulation in the area, and then calculates the water coverage rate of the lower surface of the smoke shield according to the water accumulation situation in different areas, and then adjusts the gear of the fan system according to the water coverage rate of the lower surface of the smoke shield.

[0021] After the MCU controller collects the temperature difference caused by the heat dissipation of condensed water in the thermoelectric thin film layer in a certain area, resulting in the output voltage signal from its signal output end, the voltage signal is amplified by an amplifier circuit, and the microvolt level signal is amplified to the millivolt level or larger. Then, it is filtered by a bandpass filter circuit, and only voltage signals exceeding 50μV are allowed to pass. In this way, only the voltage signal caused by water droplet condensation or dripping is retained, and the voltage signals caused by other reasons are filtered out. The voltage signal after filtering by the bandpass filter circuit is marked, and the area where the voltage signal still exists after filtering by the bandpass filter circuit is marked as a water accumulation area. Then, the area units where water condensation occurs are counted and counted N. Then, the count N is divided by the total number of areas to obtain the water accumulation coverage rate η of the lower surface of the smoke shield.

[0022] When the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield is less than 5%, the speed of the fan system is adjusted to 800rpm; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies 5%≤η<20%, ​​the speed of the fan system is adjusted to 1000rpm; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies 20%≤η<40%, the speed of the fan system is adjusted to 1500rpm, the heating wire layer in the corresponding area with water accumulation is started for electric heating, and the heating power of the heating wire layer in the corresponding area with water accumulation is adjusted to 200W; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies η≥40%, the speed of the fan system is adjusted to 2000rpm, the heating wire layer in the corresponding area with water accumulation is started for electric heating, and the heating power of the heating wire layer in the corresponding area with water accumulation is adjusted to 500W.

[0023] During the actual control process, the MCU controller can also start the electric heating of the heating wire layer in the corresponding area with water accumulation only when it is counted that the water coverage rate η on the lower surface of the smoke shield is greater than 20%, and the increase in the water coverage rate η per unit time is greater than 2%.

[0024] In this embodiment, the heating wires of the heating wire layer in each area are arranged in a reciprocating zigzag S-shaped distribution, and the heating wire layer in each area is electrically connected to the MCU controller, see Figure 4As shown. The S-shaped layout of the heating wire can also play the following roles: 1. Thermal bridge channel: The high thermal conductivity of the S-shaped metal heating wire preferentially transfers heat from the condensation point to the nearest thermoelectric film unit, forming a directional heat flow channel; 2. Mechanical reinforcement: Improves the bending strength of the smoke shield (especially the glass panel); 3. Emergency heating: When current is passed, the metal heating wire itself generates Joule heat to assist in removing condensed water; 4. Condensate guidance: The protrusions or grooves of the S-shaped metal heating wire can directional guide condensed water, causing the condensed water to gather near the metal heating wire, which can be removed more quickly when heated.

[0025] In the actual control process, taking the steaming buns scenario as an example, in the initial state, η=0%, and the fan speed is controlled at 800rpm; 5 minutes later, it is detected that η=15% (that is, 3 units are marked as activated), and the fan speed is controlled to increase to 1000rpm to reduce condensation of airflow through the smoke baffle. After 10 minutes, it is detected that η=8%, and the fan speed is maintained at 1000rpm; when the range hood is turned off, the fan system automatically runs for 3 minutes, and the heating wire layer in the corresponding area is turned on for electric heating and dehumidification.

Claims

1. A range hood comprising a body, a fan system disposed therein, an inlet disposed on the body, a smoke baffle connected to the inlet of the body, and characterized in that: The lower surface of the smoke shield is divided into multiple areas, and the lower surface of each area is adhered to a thermoelectric film layer that can be independently controlled. The thermoelectric film layer in each area is electrically connected to a signal output end, and the signal output end of the thermoelectric film layer in each area is electrically connected to the MCU controller. The MCU controller collects the temperature difference caused by the heat dissipation of condensed water in the thermoelectric film layers in different areas, thereby causing the voltage signal output from its signal output end, so as to determine whether there is water accumulation in the area, and then calculates the water coverage rate of the lower surface of the smoke shield according to the water accumulation situation in different areas, and then adjusts the gear of the fan system according to the water coverage rate of the lower surface of the smoke shield.

2. The range hood according to claim 1, characterized in that: After the MCU controller collects the temperature difference caused by the heat dissipation of condensed water on the thermoelectric thin film layer in a certain area, resulting in the output of a voltage signal from its signal output end, the voltage signal is amplified by an amplifier circuit, and then filtered by a band-pass filter circuit, retaining only the voltage signal caused by condensation or dripping of water droplets, filtering out voltage signals caused by other reasons, marking the voltage signal after filtering by the band-pass filter circuit, and marking the area where the voltage signal still exists after filtering by the band-pass filter circuit as a water accumulation area.

3. The range hood according to claim 2, characterized in that: The outer surface of the thermoelectric film layer in each area is adhered to a heating wire layer, and the heating wire layer is distributed in a reciprocating and tortuous S-shape. The heating wire layer in each area is also electrically connected to the MCU controller; when the MCU controller counts that the water coverage rate of the lower surface of the smoke shield is greater than 20%, the heating wire layer in the corresponding area with water accumulation is started for electrical heating.

4. The range hood according to claim 3, characterized in that: The outer surface of the thermoelectric film layer in each area is adhered to a heating wire layer, and the heating wire layer is distributed in a reciprocating and tortuous S-shape. The heating wire layer in each area is also electrically connected to the MCU controller; when the MCU controller counts that the water accumulation coverage rate η on the lower surface of the smoke shield is greater than 20%, and the increase in the water accumulation coverage rate η per unit time is greater than 2%, the heating wire layer in the corresponding area with water accumulation is started for electrical heating.

5. The range hood according to claim 4, characterized in that: An electric control board is provided in the machine body, the MCU controller is integrated in the electric control board of the machine body, and the fan system is electrically connected to the electric control board.

6. The range hood according to claim 1, characterized in that: The outer surface of the heating wire layer in each region is also coated with an insulating layer or a hydrophobic coating.

7. The range hood according to claim 1, characterized in that: The lower surface of the smoke shield is divided into 3 rows and 6 columns, totaling 18 areas.

8. The range hood according to claim 1, characterized in that: When the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield is less than 5%, the speed of the fan system is adjusted to 800rpm; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies 5%≤η<20%, ​​the speed of the fan system is adjusted to 1000rpm; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies 20%≤η<40%, the speed of the fan system is adjusted to 1500rpm, the heating wire layer in the corresponding area with water accumulation is started for electric heating, and the heating power of the heating wire layer in the corresponding area with water accumulation is adjusted to 200W; when the MCU controller counts that the water accumulation coverage rate η of the lower surface of the smoke shield satisfies η≥40%, the speed of the fan system is adjusted to 2000rpm, the heating wire layer in the corresponding area with water accumulation is started for electric heating, and the heating power of the heating wire layer in the corresponding area with water accumulation is adjusted to 500W.

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