Range hood and control method thereof

Abstract

The present invention relates to a range hood and a control method thereof, wherein the range hood comprises: a body, having an air inlet and an air duct connected to the air inlet; a fan system, arranged in the body; a wind speed detection module, arranged in the air duct, for obtaining the wind speed of the airflow in the air duct; a heat exchange module, arranged in the air duct, having a heat exchange flow channel for airflow to pass through and for exchanging heat for the airflow passing therethrough; a temperature detection module, comprising a first temperature sensor located upstream of the heat exchange module along the airflow flow direction in the air duct and a second temperature sensor located downstream of the heat exchange module; a controller, electrically connected to the wind speed detection module, the temperature detection module and the fan system, so as to adjust the speed of the fan system according to the wind speed signal detected by the wind speed detection module and the temperature change signal of the airflow flowing through the heat exchange module detected by the temperature detection module. The range hood can provide targeted air volume adjustment according to the smoke conditions under different cooking conditions.

Description

Technical Field

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

[0002] A range hood is a kitchen appliance that purifies the kitchen environment. With the development of intelligent range hoods, existing range hoods mostly use a fume detection module or a temperature detection module to identify the fume concentration or the temperature change of the stove on the stove to control the fan of the range hood to a matching gear. Among them, there are generally two types of range hood fume detection devices: one is an infrared photoelectric sensor that directly detects the smoke concentration based on the principle of refraction of infrared light by fume. When the fume passes through the infrared light detection area, the infrared light emitted by the infrared photoelectric sensor transmitting end will be refracted to the infrared light receiving end, and the receiving end circuit will then convert the received infrared light into a voltage value output. The larger the fume, the more infrared light output from the transmitting end will be refracted into the receiving end, so the output value of the receiving end will be larger, and the size of the fume will be quantified into a specific value. The other is an infrared temperature sensor used to detect the temperature of the stove. The temperature sensor circuit is used to convert the infrared rays emitted by the detected stove into a voltage signal value output. When the stove temperature drops, the infrared rays emitted by the stove become weaker, and the output voltage signal value becomes smaller. When the stove temperature rises, the infrared rays emitted by the stove become stronger, and the output voltage signal value becomes larger. The amount of oil smoke is then judged based on the rule that the higher the stove temperature, the greater the amount of oil smoke.

[0003] For example, the Chinese invention patent application with application number CN202110612625.3 (application publication number: CN113280381A) discloses "A method for adjusting the gear position of a range hood and a range hood". The method for adjusting the gear position of a range hood includes the following steps: obtaining the change in oil fume concentration; obtaining the stove temperature; and adjusting the gear position of the fan accordingly according to the relationship between the change in oil fume concentration and the stove temperature and the fan gear position.

[0004] In the above patent application, the stove temperature information is used as a parameter to control the fan gear. However, the temperature measured by this type of infrared temperature sensor is the average temperature of a large area including the stove surface. The local temperature rise at the moment of opening and closing has little effect on the result. In addition, the temperature measured when the pot lid is covered is easily averaged by the surrounding low-temperature area. There are a large number of misjudgment situations such as wrong shutdown and non-shutdown, which may even cause the oil fume to shut down in the middle of cooking, making it inconvenient for users to actually operate. On the other hand, the oil fume concentration detection principle in this patent application also uses the principle of oil fume affecting the refractive index of light in the air to judge the amount of oil fume. In fact, it cannot distinguish between water vapor, oil fume and other smoke components, and therefore cannot provide targeted air volume gear adjustment.

[0005] Therefore, existing range hoods need further improvement. Summary of the invention

[0006] The first technical problem to be solved by the present invention is to provide a range hood that can provide targeted air volume adjustment according to the smoke conditions under different cooking conditions in view of the current status of the prior art.

[0007] The second technical problem to be solved by the present invention is to provide a control method for a range hood that provides targeted air volume adjustment according to the smoke conditions under different cooking conditions in view of the current status of the prior art.

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

[0009] A machine body having an air inlet and an air duct connected to the air inlet;

[0010] A fan system is arranged in the body;

[0011] A wind speed detection module, disposed in the air duct, for obtaining the wind speed of the airflow in the air duct;

[0012] A heat exchange module is arranged in the air duct, and has a heat exchange flow channel for air flow to pass through and for performing heat exchange on the air flow passing therethrough;

[0013] A temperature detection module, comprising a first temperature sensor located upstream of the heat exchange module and a second temperature sensor located downstream of the heat exchange module along the air flow direction in the air duct;

[0014] The controller is electrically connected to the wind speed detection module, the temperature detection module and the fan system, so as to adjust the rotation speed of the fan system according to the wind speed signal detected by the wind speed detection module and the temperature change signal of the airflow flowing through the heat exchange module detected by the temperature detection module.

[0015] In some cases, there is no cooking operation at the front end or the current cooking temperature does not meet the forced heat exchange requirements of the heat exchange module. In this case, it is not possible to effectively determine what components are dominant in the current airflow and adjust the air volume. For this reason, it also includes:

[0016] A third temperature sensor is used to detect the ambient temperature outside the machine body;

[0017] An auxiliary heating module, arranged in the air duct, located upstream of the heat exchange module along the air flow direction in the air duct, and used for heating the air flow before entering the heat exchange module;

[0018] The controller is also electrically connected to the third temperature sensor and the auxiliary heating module, so as to control the auxiliary heating module to be turned on or off according to the difference between the temperature detected by the third temperature sensor and the temperature detected by the first temperature sensor.

[0019] When there is no cooking at the front end or the temperature has not risen, it can be heated by the auxiliary heating module, and then the fan can be started at a low gear to draw gas and create a forced convection heat exchange effect. This can effectively and quickly determine what components are dominant in the current airflow and improve the sensitivity of air volume adjustment.

[0020] Generally, the heat exchange module can be a heat exchanger with a built-in phase change fluid, a conventional radiator, etc. For the convenience of installation in the machine body, the heat exchange module includes heat sinks arranged in sequence and used to cool the airflow, and the gap between two adjacent heat sinks forms the heat exchange flow channel. The heat sink preferably uses heat sink fins with good heat dissipation effect.

[0021] Since the airflow in the air duct is not stable, and the temperature change of the airflow after passing through the heat exchange module is closely related to the airflow velocity, in order to ensure that the airflow entering the heat exchange module is maintained at a stable flow rate, thereby improving the air volume control accuracy, the range hood also includes:

[0022] The rectifier module is arranged in the air duct and is located upstream of the heat exchange module along the air flow direction in the air duct. The rectifier module has a plurality of rectifier channels arranged in sequence, and the outlet of each rectifier channel is opposite to the inlet of the heat exchange channel of the heat exchange module.

[0023] Generally, the auxiliary heating module can be independently provided from the rectifier module. In order to save space and realize rapid heating of the airflow to be introduced into the heat exchange channel, the auxiliary heating module is a heating element provided on the rectifier module. Preferably, the auxiliary heating module can be a heating film attached to the rectifier module.

[0024] In order to achieve accurate measurement of the air flow velocity, the wind speed detection module is a wind pressure sensor or a wind pressure sensor arranged at the outlet of the heat exchange flow channel of the heat exchange module.

[0025] The technical solution adopted by the present invention to solve the second technical problem is: a control method of a range hood, comprising the following steps:

[0026] The wind speed detection module obtains the wind speed V1 of the airflow in the air duct, the first temperature sensor of the temperature detection module obtains the first temperature T1 of the airflow before entering the heat exchange module, and the second temperature sensor of the temperature detection module obtains the second temperature T2 of the airflow after heat exchange by the heat exchange module. The temperature difference of the airflow passing through the heat exchange module is recorded as △Tm, △Tm=T1-T2. According to the mapping relationship of wind speed-temperature difference of airflow before and after the heat exchange module-fan speed pre-stored in the controller, the speed of the fan system is adjusted to the preset speed.

[0027] Since the heat exchange effect is greatly affected by wind speed, in order to more accurately determine the main components of the current airflow and then perform targeted fan air volume adjustment, the following steps are also included:

[0028] The wind speed in the mapping relationship of wind speed-temperature difference of airflow before and after the heat exchange module-fan speed pre-stored in the controller includes at least two wind speed intervals. For each wind speed interval, it is determined whether the temperature difference ΔTm of the airflow flowing through the heat exchange module is within the set temperature variation range (Ta, Tb] corresponding to the wind speed interval:

[0029] If △Tm≤Ta, the wind speed of the fan system is switched or maintained at a low air volume state;

[0030] If Ta<△Tm≤Tb, the wind speed of the fan system is switched or maintained at a high wind volume state;

[0031] If △Tm>Tb, the fan system is shut down.

[0032] Experiments show that the above three situations often correspond to whether the "main component of the airflow" is mostly water vapor or oil smoke. Therefore, this can be used to judge the smoke (airflow) situation under the current cooking conditions, and then provide targeted air volume adjustment.

[0033] The specific heat of oil smoke, water vapor, and air in the airflow is different. p空气 =1.005KJ / (kg*k), C p水蒸气 =1.525KJ / (kg*k), C p油烟气 =1.125KJ / (kg*k), where K is Kelvin. During the cooking process, the airflow rectified by the front-end rectifier module passes through the heat exchange module. Because the specific heat of different airflow components at a certain speed (wind speed) is different, the airflow temperature changes after passing through the heat exchange module will be different. Then, the reference temperature change difference can be determined through the mapping relationship table obtained from the previous test of wind speed, temperature change (in this embodiment, the temperature after the heat exchange module is a downward trend), main components of the airflow, etc., to determine which component (water vapor or oil smoke) is the majority of the current airflow, and then adjust the fan to run at a matching wind speed.

[0034] In some cases, there is no cooking operation at the front end or the temperature of the current cooking condition does not meet the forced heat exchange requirement of the heat exchange module. In this case, it is not possible to effectively determine what components are dominant in the current airflow and adjust the air volume. For this reason, the control method of the range hood also includes the following steps:

[0035] S11, the third temperature sensor obtains the ambient temperature T3 outside the range hood, the first temperature sensor of the temperature detection module obtains the first temperature T1 of the airflow before entering the heat exchange module, the difference between the first temperature T1 and the ambient temperature is recorded as △Tn=T1-T3, and it is determined whether △Tn is greater than the set value T0, if yes, then go to step S2; if not, then go to step S12;

[0036] S12, operating the fan system of the range hood at a low speed, and starting the auxiliary heating module and operating it for a set time t to heat the airflow in the air duct before it enters the heat exchange module, and then returning to step S11;

[0037] S2. The wind speed detection module obtains the wind speed V1 of the airflow in the air duct. The second temperature sensor of the temperature detection module obtains the second temperature T2 of the airflow after heat exchange by the heat exchange module. The temperature difference of the airflow flowing through the heat exchange module is △Tm=T1-T2. According to the pre-stored mapping relationship table of wind speed-temperature difference of the airflow before and after the heat exchange module-fan speed, the speed of the fan system is adjusted to the preset speed.

[0038] In order to adjust the fan to the low speed gear in time, after step S11 and before step S12, the following steps are also included:

[0039] The wind speed detection module obtains the wind speed V1 of the airflow in the air duct and determines whether the wind speed V1 is within the set wind speed range (V0, Va]:

[0040] If V1≤V0, it is judged that the current wind speed is very low and there is no forced convection heat exchange effect, the range hood is started, and the fan system runs at a low speed;

[0041] If V0<V1≤Va, the current wind speed is judged to be moderate, and the fan system maintains the low speed gear;

[0042] If V1>Va, it is determined that the current wind speed is relatively high, and then the gear of the fan system of the range hood is lowered to run at a low speed gear.

[0043] Compared with the prior art, the advantages of the present invention are as follows: the present invention utilizes the different specific heat capacities of the main components of the airflow (such as oil smoke, water vapor, and air), and designs a wind speed detection module, a heat exchange module, and a temperature detection module in the air duct of the machine body. The current smoke condition (whether the main component of the airflow is mostly water vapor or oil smoke) is judged by the change in the airflow temperature behind the heat exchange module at a certain wind speed, and then the front-end cooking is judged whether it is stir-frying, steaming, or shutting down, and targeted air volume adjustment is performed to bring a more accurate and reliable intelligent experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a schematic diagram of the three-dimensional structure of a range hood according to an embodiment of the present invention;

[0045] Figure 2 It is a three-dimensional cross-sectional view of a range hood according to an embodiment of the present invention (the fume collecting hood of the range hood is omitted);

[0046] Figure 3 It is a schematic diagram of the arrangement structure of components such as a rectifier module, a heat exchange module, a wind speed detection module and a temperature detection module according to an embodiment of the present invention;

[0047] Figure 4 is a flow chart of a control method for a range hood according to an embodiment of the present invention;

[0048] Figure 5 It is a temperature variation curve diagram of airflows of different components in the air duct of the range hood according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention is further described in detail below with reference to the accompanying drawings.

[0050] In the specification and claims of the present invention, terms indicating directions, such as "front", "rear", "up", "down", "left", "right", "side", "top", "bottom", etc., are used to describe various exemplary structural parts and elements of the present invention, but these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only used as explanations and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0051] See also Figure 1-Figure 5A range hood includes a body 10 and a fan system 20 disposed in the body 10. The fan system 20 is disposed in the body 10 and is used to provide negative pressure for sucking and exhausting smoke (including oil smoke, water vapor, etc.). Taking a top-suction range hood as an example, the body 10 of the range hood generally includes a fan frame 11 and a smoke hood 12 disposed at the bottom of the fan frame 11 and connected to the fan frame 11, and the lateral width of the smoke hood 12 is greater than the lateral width of the fan frame 11. An air inlet 120 is provided at the bottom of the smoke hood 12. The fan system 20 is disposed in the fan frame 11, and the space in the fan frame 11 forms an air duct 13 connected to the air inlet 120 of the smoke hood 12, which is used for external smoke airflow to enter from the air inlet 120 to the air intake of the fan system 20.

[0052] See also Figure 2 and Figure 3 The range hood further comprises a rectifier module 31, a temperature detection module, a wind speed detection module 35 and a heat exchange module 34 arranged in the air duct 13, wherein the temperature detection module comprises a first temperature sensor 33 and a second temperature sensor 36. The rectifier module 31, the first temperature sensor 33, the heat exchange module 34, the wind speed detection module 35 and the second temperature sensor 36 are arranged in sequence along the air flow direction in the air duct 13, and the air flow direction in the air duct 13 is as follows: Figure 2 and Figure 3 As shown by the arrow in FIG. 3 . The wind speed detection module 35 may be a wind pressure sensor or a wind pressure sensor.

[0053] The rectifier module 31 is a honeycomb structure as a whole, and has a plurality of rectifier channels 310 arranged in sequence. The heat exchange module 34 has a heat exchange channel 340 for airflow to pass through and for heat exchange of the airflow passing therethrough. Specifically, the heat exchange module 34 includes heat sinks 341 (such as heat sink fins) arranged in sequence and used to cool the airflow, wherein the gap between two adjacent heat sinks 341 forms the above-mentioned heat exchange channel 340. The outlet of each rectifier channel 310 of the rectifier module 31 is opposite to the inlet of the heat exchange channel 340 of the heat exchange module 34. Since the airflow in the air duct 13 is not stable, and the temperature change of the airflow after passing through the heat exchange module 34 is closely related to the airflow velocity, the setting of the above-mentioned rectifier module 31 ensures that the airflow entering the heat exchange module 34 can be maintained at a stable velocity state, thereby improving the air volume control accuracy of the fan system 20.

[0054] The first temperature sensor 33 is disposed between the rectifier module 31 and the heat exchange module 34, and is used to detect the first temperature of the airflow before entering the heat exchange module 34. The second temperature sensor 36 and the wind speed detection module 35 are both disposed at the outlet of the heat exchange flow channel 340 of the heat exchange module 34, that is, downstream of the heat exchange module 34 along the flow direction of the airflow in the air duct 13. The second temperature sensor 36 is used to detect the second temperature of the airflow after being cooled by the heat exchange module 34.

[0055] The rectifier module 31 , the temperature detection module, the wind speed detection module 35 and the heat exchange module 34 can be arranged as a module unit, so that the module unit can be conveniently installed on the inner side wall of the front cover plate of the fan rack 11 .

[0056] The specific heat of oil smoke, water vapor, and air in the airflow is different. p空气 =1.005KJ / (kg*k), C p水蒸气 =1.525KJ / (kg*k), C p油烟气 =1.125KJ / (kg*k), where K is Kelvin temperature. During the cooking process, the airflow rectified by the front-end rectifier module undergoes forced heat exchange through the heat exchange module. Because the specific heat of airflows of different components is different at a certain speed (wind speed), the temperature change of the airflow after passing through the heat exchange module will be different. Then, the reference temperature change difference can be determined through the mapping relationship table obtained from the previous test of wind speed, temperature change (in this embodiment, the temperature after passing through the heat exchange module is a downward trend), main components of the airflow, etc., to determine which component is the majority of the current airflow, and then adjust the fan to run at a matching wind speed. See Figure 5 , showing the temperature change trend of the airflow during forced heat exchange at the location of the heat exchange module (such as the location of A in Figure 5) during the process of the airflow entering from the air inlet of the body to flowing out from the air outlet of the body.

[0057] Continue to see Figure 5 In the process of the airflow entering from the air inlet 120 of the body 10 and flowing out from the air outlet of the body 10, the temperature of the airflow is gradually reduced. In some cases, such as when there is no cooking operation at the front end or the temperature of the current cooking situation does not meet the forced heat exchange requirement of the heat exchange module 34, the heat exchange process of the heat exchange module 34 cannot be used to further cool down the air. Therefore, it is not possible to effectively judge what components are dominant in the current airflow and perform subsequent air volume adjustment through the temperature change of the airflow. For this reason, a third temperature sensor 37 is provided on the outer surface of the body 10 of the range hood (such as the outer wall surface of the top of the fan frame 11 away from the oil smoke) to detect the ambient temperature T3 outside the body 10. The difference between the first temperature T1 of the airflow in the air duct 13 detected by the first temperature sensor 33 and the ambient temperature T3 detected by the third temperature sensor 37 is used to judge whether the cooker is in a state of not being turned on and having no heat source at the bottom.

[0058] An auxiliary heating module 32 is also provided in the air duct 13 of the machine body 10. The auxiliary heat dissipation module is located upstream of the heat exchange module 34 along the air flow direction in the air duct 13, and is used to heat the airflow before entering the heat exchange module 34. Generally, the auxiliary heating module 32 can be provided independently of the rectifier module 31, but in order to save space and realize the rapid heating of the airflow to enter the heat exchange flow channel 340, the auxiliary heating module 32 of this embodiment is a heating element provided on the rectifier module 31, for example, the auxiliary heating module 32 can be a heating film attached to the rectifier module 31.

[0059] The controller of the range hood of this embodiment is electrically connected to the wind speed detection module 35, the temperature detection module, the third temperature sensor 37, the auxiliary heating module 32 and the fan system 20, so as to reflect (to a certain extent) what components the current airflow is dominated by based on the wind speed signal detected by the wind speed detection module 35 and the temperature change signal of the airflow flowing through the heat exchange module 34 detected by the temperature detection module, and then adjust the speed of the fan system 20 to a wind speed gear that matches the current airflow situation. On the other hand, when the difference between the temperature detected by the third temperature sensor 37 and the temperature detected by the first temperature sensor 33 is less than the set value, the auxiliary heating module 32 is controlled to be turned on, and turned off after working for a set time.

[0060] See also Figure 4 , a control method for a range hood, comprising the following steps:

[0061] S101, start the range hood;

[0062] S102, determining whether the user performs manual operation, if yes, entering manual operation mode, if no, entering step S103;

[0063] S103, determining whether the user turns on the smart mode, if yes, starting the smart monitoring mode, if no, returning to step S102;

[0064] S11, after starting the intelligent monitoring mode, the third temperature sensor 37 obtains the ambient temperature T3 outside the range hood body 10, and the first temperature sensor 33 of the temperature detection module obtains the first temperature T1 of the airflow before entering the heat exchange module 34. The difference between the first temperature T1 and the ambient temperature is recorded as △Tn=T1-T3, and it is determined whether △Tn is greater than the set value T0. If yes, it goes to step S2; if not, it goes to step S12;

[0065] S12, operating the fan system 20 of the range hood at a low speed, and starting the auxiliary heating module 32 and operating it for a set time t to heat the airflow in the air duct 13 before entering the heat exchange module 34, and then returning to step S11;

[0066] In order to adjust the fan to the low speed gear in time, after step S11 and before step S12, the following steps are also included:

[0067] The wind speed detection module 35 obtains the wind speed V1 of the airflow in the air duct 13, and determines whether the wind speed V1 is within the set wind speed interval range (V0, Va]:

[0068] If V1≤V0, it is determined that the current wind speed is very low and there is no forced convection heat exchange effect, the range hood is started, and the fan system 20 runs at a low speed;

[0069] If V0<V1≤Va, it is determined that the current wind speed is moderate, and the fan system 20 maintains the low speed gear;

[0070] If V1>Va, it is determined that the current wind speed is relatively high, and then the gear of the fan system 20 of the range hood is lowered to operate at a low speed gear.

[0071] S2, the wind speed detection module 35 obtains the wind speed V1 of the airflow in the air duct 13, the second temperature sensor of the temperature detection module obtains the second temperature T2 of the airflow after heat exchange by the heat exchange module 34, and the temperature difference △Tm of the airflow flowing through the heat exchange module 34 is equal to T1-T2. According to the pre-stored mapping relationship table of wind speed-temperature difference of the airflow before and after the heat exchange module-fan speed, the current airflow condition (mainly water vapor or oil fume components) is judged, and the speed of the fan system 20 is adjusted to a speed matching the airflow condition.

[0072] Since the heat exchange effect is greatly affected by the wind speed, in order to more accurately determine the main components of the current airflow and then perform targeted fan air volume adjustment, the control method of the range hood also includes the following steps:

[0073] The wind speed information in the mapping relationship between wind speed, temperature difference of airflow before and after the heat exchange module, and fan speed pre-stored in the controller includes at least two wind speed intervals. For each wind speed interval, it is necessary to determine whether the temperature difference ΔTm of the airflow flowing through the heat exchange module 34 is within the set temperature variation range (Ta, Tb] corresponding to the wind speed interval, such as Figure 3 As shown, the wind speed interval is divided into four continuous interval ranges, such as (V0, Va], (Va, Vb], (Vb, Vc], (Vc, Vd], and for each wind speed interval, the temperature change range (Ta, Tb] corresponding to the wind speed interval can be selected from the database pre-stored in the controller, and then the main components of the airflow are determined by judging whether the temperature difference △Tm of the airflow flowing through the heat exchange module 34 is within the set temperature change range (Ta, Tb] corresponding to the wind speed interval. Among them, for each wind speed interval, the temperature change range (Ta, Tb] corresponding to the wind speed interval is also different.

[0074] The process of determining the main components of the airflow is as follows:

[0075] If △Tm≤Ta, (which reflects to some extent that the current airflow component is mainly water vapor), the wind speed of the fan system 20 is switched or maintained at a low air volume state;

[0076] If Ta<△Tm≤Tb, (which reflects to some extent that the current airflow component is mainly oil smoke), the wind speed of the fan system 20 is switched or maintained at a high air volume state;

[0077] If ΔTm>Tb, (which reflects to some extent that the water vapor and oil smoke content of the current airflow is not high and is mainly air), the fan system 20 is turned off.

[0078] This embodiment utilizes the different specific heat capacities of the main components of the airflow (such as oil smoke, water vapor, and air), and designs a wind speed detection module 35, a heat exchange module 34, and a temperature detection module in the air duct 13 of the machine body 10. The main components of the current airflow are judged by the temperature change of the airflow behind the heat exchange module 34, and then the front-end cooking is judged to be stir-frying, steaming, or shut down, realizing active adjustment of the air volume and automatic control of the gear, bringing a more accurate and reliable intelligent experience. On the other hand, when there is no cooking at the front end or the temperature has not risen, it can be heated by the auxiliary heating module 32, and then the fan is started at a low gear, the gas is sucked and heated to enter the air duct 13, creating a forced convection heat exchange effect that meets the temperature requirements of the heat exchange module 34, so that the airflow components can be effectively and quickly detected and judged, and the sensitivity of air volume adjustment can be improved.

Claims

1. A range hood, comprising: A machine body (10) having an air inlet (120) and an air duct (13) connected to the air inlet (120); A fan system (20) is arranged in the machine body (10); Features Also includes: A wind speed detection module (35), disposed in the wind duct (13), and used to obtain the wind speed of the airflow in the wind duct (13); A heat exchange module (34) is disposed in the air duct (13) and has a heat exchange flow channel (340) for air flow to pass through and for performing heat exchange on the air flow passing through the heat exchange module (340); A temperature detection module, comprising a first temperature sensor (33) located upstream of the heat exchange module (34) along the air flow direction in the air duct (13) and a second temperature sensor (36) located downstream of the heat exchange module (34); A controller is electrically connected to the wind speed detection module (35), the temperature detection module and the fan system (20), so as to adjust the rotation speed of the fan system (20) according to the wind speed signal detected by the wind speed detection module (35) and the temperature change signal of the airflow flowing through the heat exchange module (34) detected by the temperature detection module.

2. The range hood according to claim 1, characterized in that Also includes: a third temperature sensor (37), used for detecting the ambient temperature outside the machine body (10); an auxiliary heating module (32), arranged in the air duct (13), located upstream of the first temperature sensor (33) along the flow direction of the air flow in the air duct (13), and used for heating the air flow before entering the heat exchange module (34); The controller is also electrically connected to the third temperature sensor (37) and the auxiliary heating module (32), so as to control the auxiliary heating module (32) to be turned on or off according to the difference between the temperature detected by the third temperature sensor (37) and the temperature detected by the first temperature sensor (33).

3. The range hood according to claim 2, characterized in that: The heat exchange module (34) comprises heat sinks (341) arranged in sequence and spaced apart for cooling the airflow, and the gap between two adjacent heat sinks (341) forms the heat exchange flow channel (340).

4. The range hood according to claim 2, characterized in that Also includes: A rectifier module (31) is arranged in the air duct (13) and is located upstream of the heat exchange module (34) along the air flow direction in the air duct (13). The rectifier module (31) has a plurality of rectifier channels (310) arranged in sequence, and the outlet of each rectifier channel (310) is opposite to the inlet of the heat exchange channel (340) of the heat exchange module (34).

5. The range hood according to claim 4, characterized in that: The auxiliary heating module (32) is a heating element arranged on the rectification module (31).

6. The range hood according to claim 2, characterized in that: The wind speed detection module (35) is a wind pressure sensor or a wind pressure sensor provided at the outlet of the heat exchange flow channel (340) of the heat exchange module (34).

7. A control method for a range hood as claimed in claim 1, characterized in that The following steps are involved: The wind speed detection module (35) obtains the wind speed V1 of the airflow in the air duct (13), the first temperature sensor (33) of the temperature detection module obtains the first temperature T1 of the airflow before entering the heat exchange module (34), and the second temperature sensor (36) of the temperature detection module obtains the second temperature T2 of the airflow after heat exchange in the heat exchange module (34). The temperature difference of the airflow passing through the heat exchange module (34) is recorded as ΔTm, ΔTm=T1-T2. According to the mapping relationship of wind speed-temperature difference of the airflow before and after the heat exchange module-fan speed pre-stored in the controller, the speed of the fan system (20) is adjusted to a preset speed.

8. The control method of the range hood according to claim 7, characterized in that The following steps are also included: The wind speed in the mapping relationship of wind speed, temperature difference of airflow before and after the heat exchange module, and fan speed pre-stored in the controller includes at least two wind speed intervals. For each wind speed interval, it is determined whether the temperature difference ΔTm of the airflow flowing through the heat exchange module (34) is within a set temperature variation range (Ta, Tb] corresponding to the wind speed interval: If △Tm≤Ta, the wind speed of the fan system (20) is switched or maintained at a low air volume state; If Ta<△Tm≤Tb, the wind speed of the fan system (20) is switched or maintained at a high wind speed state; If ΔTm>Tb, the fan system (20) is turned off.

9. A control method for a range hood as claimed in any one of claims 2 to 6, characterized in that The following steps are involved: S11, the third temperature sensor (37) obtains the ambient temperature T3 outside the body (10) of the range hood, the first temperature sensor of the temperature detection module obtains the first temperature T1 of the airflow before entering the heat exchange module (34), the difference between the first temperature T1 and the ambient temperature is recorded as ΔTn=T1-T3, and it is determined whether ΔTn is greater than the set value T0, if yes, then go to step S2; if not, then go to step S12; S12, the fan system (20) of the range hood is operated at a low speed gear, and the auxiliary heating module (32) is started and operated for a set time t to heat the airflow in the air duct (13) before entering the heat exchange module (34), and then the process returns to step S11; S2, the wind speed detection module (35) obtains the wind speed V1 of the airflow in the air duct (13), the second temperature sensor (36) of the temperature detection module obtains the second temperature T2 of the airflow after heat exchange in the heat exchange module (34), the temperature difference △Tm of the airflow flowing through the heat exchange module (34) = T1-T2, and the speed of the fan system (20) is adjusted to a preset speed according to a pre-stored mapping relationship table of wind speed-temperature difference of the airflow before and after the heat exchange module-fan speed.

10. The control method of the range hood according to claim 9, characterized in that: After step S11 and before step S12, the following steps are also included: The wind speed detection module (35) obtains the wind speed V1 of the airflow in the air duct (13), and determines whether the wind speed V1 is within a set wind speed interval range (V0, Va]): If V1≤V0, it is determined that the current wind speed is very low and there is no forced convection heat exchange effect, the range hood is started, and the fan system (20) runs at a low speed; If V0<V1≤Va, it is determined that the current wind speed is moderate, and the fan system (20) maintains the low speed gear position; if V1>Va, it is determined that the current wind speed is high, and then the gear position of the fan system (20) of the range hood is lowered to operate at a low speed gear position.

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