Control method of tandem double-fan range hood and tandem double-fan range hood

Abstract

The present application relates to the technical field of range hood, and particularly relates to a control method of a series connection type double-fan range hood and the series connection type double-fan range hood controlled by the control method. The control method of the series connection type double-fan range hood is used for controlling the rotating speeds of the upper fan and the lower fan in series connection. The air outlet of the upper fan is connected with an external flue, and the air inlet of the lower fan is connected with a suction port. After the series connection type double-fan range hood is started, it enters one of the working modes, and in each working mode, the rotating speed of the lower fan is greater than or equal to the rotating speed of the upper fan. In each working mode, the rotating speed of the lower fan is greater than or equal to the rotating speed of the upper fan, so that the negative pressure formed at the air inlet of the lower fan is greater than or equal to the negative pressure at the air outlet of the upper fan. Since the air inlet of the lower fan is close to the suction port, the suction efficiency can be improved, and the energy consumption can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of range hoods, and in particular to a control method for a series-type dual-fan range hood and a series-type dual-fan range hood. Background Art

[0002] The tandem dual-fan range hood consists of a smoke hood, a bellows, an upper fan, and a lower fan. The bellows is mounted above the smoke hood, the lower fan is mounted inside the smoke hood, and the upper fan is mounted inside the bellows. The two fans are arranged vertically, allowing the entire machine to achieve a large smoke exhaust volume.

[0003] In the existing series-type dual-fan range hoods, the upper and lower fans are in different working conditions. For the lower fan, the shape of the smoke hood's air inlet, the smoke baffle and the filter structure are the main sources of resistance. For the upper fan, the shape of the bellows' exhaust port, the check valve at the exhaust port, the public flue connected to the outside and the congestion of the public flue are the main sources of resistance. Due to the different working conditions of the two fans, that is, the different flow losses, the two fans in series are generally set to different speeds (or gears) under different working conditions. However, if the speed setting between the two fans is unreasonable, not only will the working efficiency of the whole machine be low, but the working energy consumption will also increase. Summary of the Invention

[0004] One of the technical problems solved by the present invention is to provide a control method for a series-connected dual-fan range hood, which can effectively solve the technical problems of low working efficiency and high energy consumption of the upper and lower fans in series in the prior art.

[0005] The second technical problem solved by the present invention is to provide a series-connected dual-fan range hood, which can effectively solve the technical problems of low working efficiency and high energy consumption of the upper and lower fans in series in the prior art.

[0006] The first technical problem mentioned above is solved by the following technical solution:

[0007] A control method for a series-connected dual-fan range hood is used to control the rotational speeds of an upper fan and a lower fan in series, wherein the air outlet of the upper fan is connected to an external flue, and the air inlet of the lower fan is connected to a smoke outlet. After the series-connected dual-fan range hood is turned on, it enters one of the operating modes, and in each of the operating modes, the rotational speed of the lower fan is greater than or equal to the rotational speed of the upper fan.

[0008] Compared with the background technology, the control method of the series-connected dual-fan range hood of the present invention has the following beneficial effects:

[0009] Because the down fan is closer to the smoke outlet, its primary function is to extract the fumes from the smoke outlet. The up fan, on the other hand, is farther away from the smoke outlet, so its primary function is to overcome the resistance of the common flue and the check valve. In each operating mode, when the down fan's speed is greater than or equal to that of the up fan, meaning the negative pressure at the down fan's air inlet is greater than or equal to the negative pressure at the up fan's air outlet, the down fan and the up fan will each perform their respective primary functions. If the down fan's speed is lower than that of the up fan, meaning the negative pressure at the down fan's air inlet is lower than the negative pressure at the up fan's air outlet, the up fan will assist the down fan in extracting the fumes from the smoke outlet. However, because the up fan's air inlet is farther away from the smoke outlet, this assisting extraction process results in significant energy loss, reducing smoke extraction efficiency. Therefore, by controlling the up fan's speed to be less than or equal to that of the down fan, not only can smoke extraction efficiency be improved, but energy loss can also be reduced, achieving energy-saving benefits.

[0010] In one embodiment, after the series dual-fan range hood is turned on, the real-time current I of the upper fan is detected; the upper fan has at least a first set current I1 and a second set current I2 according to the congestion of the external flue, and the first set current I1 is greater than the second set current I2;

[0011] When I>I1, the series dual-fan range hood enters the first operating mode, and the upper fan runs at the first speed n1;

[0012] When I2≤I≤I1, the series-connected dual-fan range hood enters the second operating mode, and the upper fan runs at the second speed n2;

[0013] When I<I2, the series dual-fan range hood enters the third working mode, and the upper fan runs at the third speed n3; the first speed n1, the second speed n2 and the third speed n3 increase gradually.

[0014] In one embodiment, in the first working mode, the downwind fan operates at a fourth speed n4; in the second working mode and the third working mode, the downwind fan operates at a fifth speed n5, and the fourth speed n4 is less than the fifth speed n5.

[0015] In one embodiment, after the series-connected dual-fan range hood operates in the first working mode for the first set time T1, the real-time current I of the upper fan is re-detected, and the working mode of the series-connected dual-fan range hood is adjusted again according to the magnitude of the real-time current I.

[0016] In one embodiment, after the series-type dual-fan range hood operates in the second working mode and the third working mode for a set time, it re-enters the first working mode and operates for a set time, and then detects the real-time current I of the upper fan again, and readjusts the working mode of the series-type dual-fan range hood according to the size of the real-time current I.

[0017] In one embodiment, the second set time T2 of the second working mode is greater than the third set time T3 of the third working mode.

[0018] In one embodiment, the series dual-fan smoke stack enters a monitoring mode when it is shut down to detect the real-time pressure P of the external flue, and the real-time pressure P is compared with the reference pressure P1 when smoke backflow occurs in the external flue;

[0019] If P<P1, it is determined that no smoke backflow occurs in the external flue, and the upper fan remains closed;

[0020] If P≥P1, it is determined that smoke backflow occurs in the external flue, and the upper fan is turned on.

[0021] In one embodiment, when smoke backflow occurs in the external flue, the upper blower operates at the first speed n1.

[0022] In one embodiment, after the upper blower is turned on for a fourth set time T4, the real-time pressure P of the external flue is re-detected to determine whether the external flue continues to flow back.

[0023] The second technical problem mentioned above is solved by the following technical solution:

[0024] A series-connected dual-fan range hood comprises an upper fan and a lower fan connected in series, wherein the upper fan and the lower fan adjust their respective rotation speeds by the above-mentioned control method for the series-connected dual-fan range hood.

[0025] Compared with the background technology, the series-connected dual-fan range hood of the present invention has the following beneficial effects:

[0026] In each working mode, the speed of the lower fan is greater than or equal to the speed of the upper fan, so that the negative pressure formed at the air inlet of the lower fan is greater than or equal to the negative pressure at the air outlet of the upper fan. Since the air inlet of the lower fan is closer to the smoke outlet, it can not only improve the smoke extraction efficiency of the series-connected dual-fan range hood, but also reduce the energy loss of the entire machine, thereby achieving energy-saving effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a cross-sectional view of a series-type dual-fan range hood provided by an embodiment of the present invention;

[0028] Figure 2 This is a detailed flow chart of the working mode of the control method of the series-type dual-fan range hood provided by an embodiment of the present invention;

[0029] Figure 3 It is a detailed flow chart of the monitoring mode of the control method of the series-connected dual-fan range hood provided by an embodiment of the present invention.

[0030] The names and numbers of the components in the figure are as follows:

[0031] 1. Fume hood; 2. Bellows; 22. Exhaust vent; 3. Upper fan; 4. Lower fan; 5. Pressure sensor. DETAILED DESCRIPTION

[0032] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the drawings only show portions relevant to the present invention, not all of them.

[0033] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0034] In the description of this embodiment, terms such as "upper," "lower," "right," and "left" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0035] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0036] like Figure 1 As shown, this embodiment proposes a dual-fan range hood, which includes a smoke hood 1, a bellows 2, an upper fan 3 and a lower fan 4. The bellows 2 is connected and installed above the smoke hood 1, the upper fan 3 is installed in the bellows 2, and the lower fan 4 is installed in the smoke hood 1.

[0037] In the existing series-type dual-fan range hoods, the upper and lower fans are in different working conditions. For the lower fan, the shape of the smoke hood's air inlet, the smoke baffle and the filter structure are the main sources of resistance. For the upper fan, the shape of the bellows' exhaust port, the check valve at the exhaust port, the public flue connected to the outside and the congestion of the public flue are the main sources of resistance. Due to the different working conditions of the two fans, that is, the different flow losses, the two fans in series are generally set to different speeds (or gears) under different working conditions. However, if the speed setting between the two fans is unreasonable, not only will the working efficiency of the whole machine be low, but the working energy consumption will also increase.

[0038] In order to solve the above problems, Figure 1 and Figure 2 As shown, this embodiment also proposes a control method for a series-connected dual-fan range hood, which is used to control the rotational speeds of an upper fan 3 and a lower fan 4 connected in series. The air outlet of the upper fan 3 is connected to the external flue, and the air inlet of the lower fan 4 is connected to the smoke outlet. After startup, the series-connected dual-fan range hood enters one of its operating modes, and in each operating mode, the rotational speed of the lower fan 4 is greater than or equal to that of the upper fan 3. Because the lower fan 4 is closer to the smoke outlet, its primary function is to draw in oil fumes from the smoke outlet. The upper fan 3, however, is farther away from the smoke outlet and therefore primarily functions to overcome resistance from the common flue and the check valve. In each working mode, the speed of the lower fan 4 is greater than or equal to the speed of the upper fan 3, that is, when the negative pressure formed at the air inlet of the lower fan 4 is greater than or equal to the negative pressure at the air outlet of the upper fan 3, the lower fan 4 and the upper fan 3 will each play their main role; if the speed of the lower fan 4 is less than the speed of the upper fan 3, that is, when the negative pressure formed at the air inlet of the lower fan 3 is less than the negative pressure at the air outlet of the upper fan 4, the upper fan 4 will assist the lower fan 3 in sucking the oil smoke from the smoke outlet. However, since the air inlet of the upper fan 4 is far away from the smoke outlet, a large amount of energy will be lost in the process of assisting the suction, resulting in a decrease in the smoking efficiency. Therefore, by controlling the speed of the upper fan 3 to be less than or equal to the speed of the lower fan 4, not only can the smoking efficiency be improved, but also the energy loss of the entire machine can be reduced, achieving an energy-saving effect.

[0039] It should be noted that when the user turns on the tandem dual-fan range hood, it automatically detects the current of upper fan 3. This automatic detection takes approximately 5 to 10 seconds, allowing the detection to occur after upper fan 3 stabilizes, ensuring the stability and accuracy of the detection results. It is understood that the tandem dual-fan range hood also includes a control module, which performs logical control processes such as fan speed regulation, comparison of fan current with a set value, and comparison of real-time pressure P with reference pressure P1. Since this control module is conventional technology, its structure and operating principle will not be further described.

[0040] In this embodiment, the external flue (generally a public flue) is prone to congestion, resulting in poor smoke exhaust. Depending on the specific circumstances of the external flue congestion, it can be divided into three situations: no congestion, moderate congestion, and high congestion. Of course, in other embodiments, it is also possible to divide the congestion situation into two situations: no congestion or congestion, or to divide the congestion situation into N levels of congestion, where N can be one, two, or three or more, to divide the congestion situation into multiple levels of congestion, which is not specifically limited here.

[0041] For ease of description, the following describes in detail the congestion conditions of the external flue, which are divided into three categories: no congestion, moderate congestion, and high congestion. When congestion occurs in the external flue, the smoke exhaust resistance increases, reducing the exhaust efficiency, causing the fan load to change, and thus changing the real-time current I of the upper fan 4. The more severe the congestion in the external flue (the greater the smoke exhaust resistance), the greater the real-time current I of the upper fan 4. Therefore, the upper fan 3 has at least a first set current I1 and a second set current I2 based on the congestion condition of the external flue, with the first set current I1 being greater than the second set current I2. When I>I1, the real-time current I of the upper fan 4 detected at this time is less than the first set value I1, and the external flue is not congested; when I2≤I≤I1, the real-time current I of the upper fan 4 detected at this time is between the first set value I1 and the second set current I2, and the external flue is moderately congested; when I<I2, the real-time current I of the upper fan 4 detected at this time is less than the second set value I2, and the external flue is highly congested.

[0042] like Figure 2 As shown, the control method of the series-connected dual-fan range hood includes the following steps: after the series-connected dual-fan range hood is turned on, the real-time current I of the upper fan 3 is detected.

[0043] When I>I1, the series dual-fan range hood enters the first operating mode, and the upper fan 3 runs at the first speed n1.

[0044] When I2≤I≤I1, the series-connected dual-fan range hood enters the second operating mode, and the upper fan 3 runs at the second speed n2.

[0045] When I<I2, the series dual-fan range hood enters the third operating mode, and the upper fan 3 runs at the third speed n3. The first speed n1, the second speed n2 and the third speed n3 increase in sequence.

[0046] When the external flue is not congested, the series dual-fan range hood enters the first working mode, and the upper fan 3 runs at the first speed n1. At this time, the upper fan 3 is in a low-speed gear to reduce the energy consumption of the whole machine. When the external flue is moderately congested, the upper fan 3 runs at the second speed n2. At this time, the upper fan 3 is in a medium-speed gear, while ensuring the efficiency of smoking, the energy consumption of the whole machine is reduced as much as possible. When the external flue is highly congested, the upper fan 3 runs at the third speed n3. At this time, the upper fan 3 is in a high-speed gear to ensure smooth smoke exhaust. The speed of the upper fan 3 is adaptively adjusted according to the congestion of the external flue to reduce energy consumption while ensuring the efficiency of smoking.

[0047] like Figure 2 As shown, in the first operating mode, the lower fan 4 operates at a fourth speed n4. In the second and third operating modes, the lower fan 4 operates at a fifth speed n5, where the fourth speed n4 is less than the fifth speed n5. The fourth speed n4 is the medium speed of the lower fan 4, and the fifth speed n5 is the high speed of the lower fan 4. Since the speed of the lower fan 4 is greater than or equal to the speed of the upper fan 3 in all operating modes, the lower fan 4 generally operates at the medium-high speed.

[0048] In this embodiment, when the external flue is not congested, the whole machine enters the first working mode, the upper fan 3 runs at a low speed gear and the lower fan 4 runs at a medium speed gear, and the whole machine operates normally and exhausts smoke. When the external flue is moderately congested, the second working mode is entered, the upper fan 3 runs at a medium speed gear and the lower fan 4 runs at a high speed gear to increase the pressure (wind pressure) inside the whole machine and achieve a high wind pressure output to balance the energy consumption and smoking efficiency of the whole machine. When the external flue is highly congested, the third working mode is entered, the upper fan 3 runs at a high speed gear and the lower fan 4 runs at a high speed gear to further increase the pressure inside the whole machine and achieve a double wind pressure output to ensure smoking efficiency.

[0049] like Figure 2 As shown, after the series-type dual-fan range hood has been running in the first working mode for the first set time T1, the real-time current I of the upper fan 3 is re-detected, and the working mode of the series-type dual-fan range hood is adjusted again according to the magnitude of the real-time current I. The above-mentioned first set time T1 is approximately 20s to 90s. In other embodiments, T1 can also be set to other numerical ranges based on the frequency and duration of congestion in the external flue. By cyclically detecting the real-time current I of the upper fan 3 at intervals of the first set time T1, real-time monitoring of the congestion in the external flue is achieved, thereby flexibly adjusting the rotation speeds of the upper fan 3 and the lower fan 4 to ensure the smoking efficiency of the entire machine.

[0050] like Figure 2As shown, after the series-type dual-fan range hood operates in the second and third operating modes for a set time, it re-enters the first operating mode and operates for a set time. The real-time current I of the upper fan 3 is again detected, and the operating mode of the series-type dual-fan range hood is readjusted based on the magnitude of the real-time current I. By switching to the first operating mode after operating in both the second and third operating modes for a set time, the speeds of the upper and lower fans 3 and 4 are reduced, thereby reducing overall energy consumption and operating noise. The real-time current I of the upper fan 3 is then detected in the first operating mode to determine whether congestion in the external flue has improved or been eliminated, thereby enabling real-time monitoring of external flue congestion.

[0051] Furthermore, the second set time T2 of the second working mode is greater than the third set time T3 of the third working mode. The second set time T2 of this embodiment is approximately 120s to 180s, and the third set time T3 is approximately 60s to 90s. In other embodiments, T2 and T3 can also be set to other numerical ranges based on the frequency and duration of congestion in the external flue. Since the rotation speeds of the upper fan 3 and the lower fan 4 are both high in the third working mode, the operating time is shorter than that of the second working mode, so as to shorten the operating time of the third working mode as much as possible, thereby reducing the energy consumption of the entire machine.

[0052] like Figure 3 As shown, when the series dual-fan smoke stack is turned off, it enters the monitoring mode to detect the real-time pressure P of the external smoke duct, and the real-time pressure P is compared with the reference pressure P1 when smoke backflow occurs in the external smoke duct.

[0053] If P<P1, it is determined that no smoke backflow occurs in the external flue, and the upper fan 3 remains closed.

[0054] If P≥P1, it is determined that flue gas backflow occurs in the external flue and the upper fan 3 is turned on.

[0055] By shutting down and entering the monitoring mode, the phenomenon of smoke backflow in the series-connected dual-fan range hood can be avoided, thereby improving the user experience of the series-connected dual-fan range hood.

[0056] like Figure 1 As shown, a pressure sensor 5 is installed in the air outlet 22 at the top of the bellows 2. The pressure sensor 5 is small in size, easy to install and use, and has high measurement accuracy. The pressure sensor 5 is electrically connected to the control module to transmit the measured pressure value at the air outlet 22 to the control module.

[0057] In this embodiment, when smoke backflow occurs from the external flue, the upper fan 3 operates at the first speed n1. Specifically, when smoke backflow occurs from the external flue, the upper fan 3 is in a low speed gear, preventing smoke backflow while also reducing overall energy consumption. When the tandem dual-fan hood is shut down, the lower fan 4 remains off, and the upper fan 4, which is closer to the external flue, performs the operation, further reducing energy consumption.

[0058] like Figure 3 As shown, after the upper fan 3 is turned on for the fourth set time T4, the real-time pressure P of the external flue is re-detected to determine whether the external flue continues to flow back. The fourth set time T4 of this embodiment is approximately 5 minutes to 10 minutes. In other embodiments, T4 can also be set to other numerical ranges according to the specific situation of smoke backflow in the external flue. By cyclically detecting the real-time pressure P of the external flue, whether smoke backflow occurs in the external flue is monitored in real time, thereby ensuring that the upper fan 3 is opened or closed in time, thereby improving the control accuracy of the entire machine.

[0059] The tandem dual-fan range hood of this embodiment uses the aforementioned control method for tandem dual-fan range hoods to adjust the rotational speeds of the upper and lower fans 3 and 4. In each operating mode, both upper and lower fans 3 and 4 remain on, and the rotational speed of the lower fan 4 is greater than or equal to that of the upper fan 3. This ensures that the negative pressure at the air inlet of the lower fan 4 is greater than or equal to the negative pressure at the air outlet of the upper fan 3. Because the air inlet of the lower fan 4 is closer to the smoke outlet, this not only improves the smoke extraction efficiency of the tandem dual-fan range hood but also reduces the overall energy loss of the unit, achieving energy-saving effects.

[0060] The above embodiments merely illustrate the basic principles and features of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A control method for a series-connected double-fan range hood, for controlling the rotational speed of an upper fan (3) and a lower fan (4) connected in series, wherein the air outlet of the upper fan (3) is connected to an external flue, and the air inlet of the lower fan (4) is connected to a smoke outlet, characterized in that: The series-connected dual-fan range hood enters one of the operating modes after being turned on, and in each of the operating modes, the rotation speed of the lower fan (4) is greater than or equal to the rotation speed of the upper fan (3); After the series-type dual-fan range hood is turned on, the real-time current I of the upper fan (3) is detected; the upper fan (3) has at least a first set current I1 and a second set current I2 according to the congestion condition of the external flue, and the first set current I1 is greater than the second set current I2; When I>I1, the series-connected dual-fan range hood enters the first operating mode, and the upper fan (3) operates at the first speed n1; When I2≤I≤I1, the series-connected dual-fan range hood enters the second operating mode, and the upper fan (3) operates at the second speed n2; when When the series dual-fan range hood enters the third working mode, the upper fan (3) operates at a third speed n3; the first speed n1, the second speed n2 and the third speed n3 increase progressively.

2. The control method of the series-connected dual-fan range hood according to claim 1, characterized in that: In the first working mode, the downwind fan (4) operates at a fourth speed n4; in the second working mode and the third working mode, the downwind fan (4) operates at a fifth speed n5, and the fourth speed n4 is less than the fifth speed n5.

3. The control method of the series-connected dual-fan range hood according to claim 2, characterized in that: After the series-connected dual-fan range hood operates in the first working mode for the first set time T1, the real-time current I of the upper fan (3) is re-detected, and the working mode of the series-connected dual-fan range hood is adjusted again according to the magnitude of the real-time current I.

4. The control method of the series-connected dual-fan range hood according to claim 2, characterized in that: After the series-connected dual-fan range hood operates for a set time in the second working mode and the third working mode, it re-enters the first working mode and operates for a set time, and detects the real-time current I of the upper fan (3) again, and readjusts the working mode of the series-connected dual-fan range hood according to the magnitude of the real-time current I.

5. The control method of the series-connected dual-fan range hood according to claim 4, characterized in that: The second set time T2 for the second working mode operation is greater than the third set time T3 for the third working mode operation.

6. The control method of a series-connected dual-fan range hood according to claim 1, characterized in that: When the series dual-fan smoke stack is shut down, the smoke stack enters a monitoring mode to detect the real-time pressure P of the external smoke duct, and the real-time pressure P is compared with the reference pressure P1 when smoke backflow occurs in the external smoke duct; If P<P1, it is determined that no smoke backflow occurs in the external flue, and the upper fan (3) remains closed; If P≥P1, it is determined that smoke backflow occurs in the external flue, and the upper fan (3) is turned on.

7. The control method of the series-connected dual-fan range hood according to claim 6, characterized in that: When smoke backflow occurs in the external flue, the upper blower (3) operates at a first speed n1.

8. The control method of the series-connected dual-fan range hood according to claim 7, characterized in that: After the upper fan (3) is turned on for the fourth set time T4, the real-time pressure P of the external flue is re-detected to determine whether the external flue continues to flow back.

9. Series double-fan range hood, characterized in that: It comprises an upper fan (3) and a lower fan (4) connected in series, wherein the upper fan (3) and the lower fan (4) adjust their respective rotation speeds by the control method of the series double-fan range hood according to any one of claims 1 to 8.

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