Range hood, central smoke exhaust system and control method of central smoke exhaust system

Abstract

The invention relates to the technical field of smoke collecting and discharging machine systems, in particular to a range hood, a central smoke discharging system and a control method of the central smoke discharging system. The control method of the range hood comprises the following steps: acquiring state information of the range hood; if the extractor hood is in the starting state, air volume adjusting range information is obtained, and the air volume adjusting range information is the adjustable range of the air volume of the extractor hood; preset air volume is set based on the air volume adjusting range information; and the rotating speed of the extractor hood is adjusted based on the preset air volume. The air volume adjusting range information is obtained, the preset air volume is set based on the air volume adjusting range information, and the rotating speed of the extractor hood is adjusted based on the preset air volume, so that the air volume of the extractor hood is matched with the working environment of the extractor hood, and the phenomena that the extractor hood is insufficient in smoke discharging capacity and difficult in smoke discharging are avoided; and resource waste caused by redundancy of the smoke exhaust capacity of the range hood is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of smoke exhaust machine systems, and in particular to range hoods, central smoke exhaust systems and their control methods. Background Art

[0002] A range hood is a kitchen appliance for purifying the kitchen environment. It can quickly extract the waste generated by stove combustion and harmful fumes produced during cooking outdoors, while condensing and collecting the fumes to reduce pollution, purify the air, and has the safety guarantee functions of preventing poisoning and explosion. In related technologies, the air volume adjustment range of the range hood is set at the factory. However, due to changes in the working environment, the air volume required for the normal smoke exhaust of the range hood changes accordingly. For example, when the working environment is conducive to the smoke exhaust of the range hood, the required air volume of the range hood is small; when the working environment is not conducive to the smoke exhaust of the range hood, the required air volume of the range hood is large. And users cannot intuitively judge the impact of the working environment on the smoke exhaust of the range hood, which easily leads to unreasonable use of resources, resulting in waste of resources, or the range hood cannot be adjusted in time for smoke exhaust, and the smoke exhaust effect is poor.

[0003] In multi-story residential buildings, residents share a common smoke exhaust pipe. For low-rise users, the smoke exhaust resistance mainly comes from the common smoke exhaust pipe, including the frictional loss along the common smoke exhaust pipe and the confluence loss when the fluid flows through the smoke exhaust ports of the branch pipes of each opened upper layer users. Therefore, when the number of opened floors is large, the smoke exhaust resistance of low-rise users is high, and it is necessary to increase the suction air volume of the range hoods of low-rise users. However, this easily reaches the upper limit of the suction air volume of the range hood, and the actual smoke exhaust effect is poor. And this requires high performance of the range hood, increasing the cost of users. The range hood generates relatively large noise when working at a high suction air volume, and the user experience is poor. At the same time, there is a large gap in the smoke exhaust resistance between high-rise users and low-rise users, resulting in an embarrassing situation where the actual air volume of high-rise users is excessive while the actual air volume of low-rise users is insufficient, bringing waste of energy for high-rise users while the smoke exhaust effect of low-rise users is poor.

[0004] In related technologies, smoke exhaust is carried out through a central range hood system. The central range hood system generally uses the top fan located at the outlet of the common smoke exhaust pipe as the main or only power source, and coordinates and controls the working states of all components of the entire smoke exhaust system in real time according to the air volume requirements of the user end. There are two types of control methods for the central range hood system:

[0005] One is an open-loop control method based on the one-dimensional pneumatic model of the system. The accuracy of the air volume control of this control method depends on the accuracy of the calibration of the system resistance characteristics. In the actual use process, due to problems such as non-standard installation, component aging, and oil fume deposition, the system resistance characteristics will change, resulting in a decrease in the accuracy of air volume control;

[0006] Another type is a closed-loop control system based on the feedback control of pressure, flow rate, and current sensors. This method calculates the actual air volume at the user end in real time through sensor data and adjusts the operating point of the top fan in real time according to the deviation between the actual air volume and the preset air volume (required air volume). However, due to the serious oil fume pollution in the smoke exhaust system, it is extremely easy to cause the failure of sensors such as pressure and flow rate, and the system reliability is poor.

[0007] In addition, due to the actual smoke exhaust capacity limitations of the top fan and the user-end fan, for the same common flue, the actual maximum air volume that can be adjusted at the user end will change under different working conditions. When the adjustment exceeds the actual smoke exhaust capacity of the fan, the actual air volume of some low-floor users cannot reach the preset air volume, resulting in difficult smoke exhaust. Summary of the Invention

[0008] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention provides a control method for an oil fume extractor, including:

[0009] Obtain the status information of the oil fume extractor;

[0010] If the oil fume extractor is in the on state, obtain the air volume adjustment range information, where the air volume adjustment range information is the adjustable range of the air volume of the oil fume extractor;

[0011] Set a preset air volume based on the air volume adjustment range information;

[0012] Adjust the rotation speed of the oil fume extractor based on the preset air volume.

[0013] According to the control method for an oil fume extractor provided by an embodiment of the present invention, the step of setting a preset air volume based on the air volume adjustment range information includes:

[0014] Obtain the gear information of the oil fume extractor;

[0015] Divide the air volume adjustment range information into multiple levels of preset air volumes, and correspond each level of the preset air volume to the gear of the gear information.

[0016] According to the control method for an oil fume extractor provided by an embodiment of the present invention, the step of adjusting the rotation speed of the oil fume extractor based on the preset air volume includes:

[0017] Obtain the real-time current and real-time rotation speed of the oil fume extractor;

[0018] Calculate the real-time air volume of the oil fume extractor based on the real-time current and the real-time rotation speed;

[0019] Obtain the relative deviation between the real-time air volume and the preset air volume, and adjust the rotation speed of the oil fume extractor based on the relative deviation.

[0020] According to the control method of the range hood provided by the embodiment of the present invention, the step of obtaining the relative deviation between the real-time air volume and the preset air volume and adjusting the rotation speed of the range hood based on the relative deviation includes:

[0021] If the relative deviation is less than or equal to the preset deviation, the rotation speed of the range hood remains unchanged;

[0022] Or, if the relative deviation is greater than the preset deviation, obtain the comparison result between the real-time air volume and the preset air volume, and adjust the rotation speed of the range hood based on the comparison result between the real-time air volume and the preset air volume.

[0023] According to the control method of the range hood provided by the embodiment of the present invention, the step of, if the relative deviation is greater than the preset deviation, obtaining the comparison result between the real-time air volume and the preset air volume and adjusting the rotation speed of the range hood based on the comparison result between the real-time air volume and the preset air volume specifically includes:

[0024] If the real-time air volume is less than the preset air volume, increase the rotation speed of the range hood;

[0025] Or if the real-time air volume is greater than the preset air volume, decrease the rotation speed of the range hood.

[0026] The embodiment of the present invention also provides a range hood, which includes:

[0027] A blower, the blower is rotatable;

[0028] A sensor, the sensor is connected to the blower, and the sensor is used to detect the real-time rotation speed and real-time current of the blower;

[0029] A control module, the control module is connected to both the blower and the sensor, and the control module is used to execute the control method of the range hood as described above.

[0030] The embodiment of the present invention also provides a central smoke exhaust system, including:

[0031] A main smoke exhaust pipe, one end of the main smoke exhaust pipe is provided with a smoke exhaust port;

[0032] Multiple range hoods, the range hoods are the range hoods as described above, each range hood is communicated with the main smoke exhaust pipe, and the multiple range hoods are distributed along the length direction of the main smoke exhaust pipe;

[0033] A wind cap, the wind cap covers the smoke exhaust port;

[0034] A plurality of connecting pipes, one end of each connecting pipe is connected and communicated with the range hood, and the other end of the connecting pipe is connected and communicated with the main exhaust pipe, and each connecting pipe is connected to the range hood in a one-to-one correspondence;

[0035] A switching valve, which is arranged at the connection between the connecting pipe and the main exhaust pipe to control the on-off of the range hood and the main exhaust pipe;

[0036] A control terminal, which is communicatively connected to each range hood.

[0037] An embodiment of the present invention further provides a control method for a central exhaust system, which is applied to the central exhaust system as described above. The control method of the central exhaust system includes:

[0038] Obtain the status information of each range hood;

[0039] Calculate the air volume adjustment range information based on the status information;

[0040] Send the air volume adjustment range information to the range hood.

[0041] According to the control method of the central exhaust system provided by the embodiment of the present invention, in the step of calculating the air volume adjustment range information based on the status information, a plurality of the range hoods adopt the same air volume adjustment range information.

[0042] According to the control method of the central exhaust system provided by the embodiment of the present invention, among a plurality of the range hoods, the range hoods in the on state are working range hoods, and the range hoods in the off state are standby range hoods;

[0043] The status information includes the number of working range hoods, the floors where the working range hoods are located, and the maximum capacity characteristic pressure rise of the working range hoods.

[0044] According to the control method of the central exhaust system provided by the embodiment of the present invention, the step of calculating the air volume adjustment range information based on the status information includes:

[0045] Set the initial air volume value of the working range hood;

[0046] Set the initial value of the process air volume value of the working range hood to be equal to the initial air volume value;

[0047] Calculate the total outlet pressure of the working range hood at the lowest floor, and the outlet total pressure is the wind pressure at the connection between the connecting pipe and the main exhaust pipe;

[0048] Obtain the comparison result between the outlet total pressure and the maximum capacity characteristic pressure rise of the working range hood at the lowest floor.

[0049] According to the control method of the central smoke exhaust system provided by the embodiments of the present invention, the step of obtaining the comparison result between the total outlet pressure and the maximum characteristic pressure rise of the working smoke machine at the lowest layer specifically includes:

[0050] If the total outlet pressure is less than or equal to the maximum characteristic pressure rise of the working smoke machine at the lowest layer, the maximum value of the air volume adjustment range information is taken as the process air volume value;

[0051] Or, if the total outlet pressure is greater than the maximum characteristic pressure rise of the working smoke machine at the lowest layer, reduce the process air volume value, calculate the total outlet pressure of the working smoke machine at the lowest layer, and obtain the comparison result between the total outlet pressure and the maximum characteristic pressure rise of the working smoke machine at the lowest layer.

[0052] According to the control method of the central smoke exhaust system provided by the embodiments of the present invention, the step of calculating the total outlet pressure of the working smoke machine at the lowest layer, where the total outlet pressure is the wind pressure at the connection between the connecting pipe and the main smoke exhaust pipe specifically includes:

[0053] Calculate the total pressure at the connection between the wind cap and the main smoke exhaust pipe,

[0054] Pt_out = 0.5ρV9M) 2 +Δp_fm

[0055] Wherein, Pt_out represents the total pressure at the connection between the wind cap and the main smoke exhaust pipe, Δp_fm represents the resistance loss generated by the fluid passing through the wind cap, and V(M) represents the average flow velocity of the fluid downstream of the highest layer in the main smoke exhaust pipe;

[0056] Δp_fm = ξ_fm×0.5ρV(M) 2

[0057] Wherein, ξ_fm represents the wind cap resistance coefficient, and ρ represents the fluid density;

[0058] Perform iterative calculation on the total pressure at the location of each working smoke machine corresponding to each layer in the main smoke exhaust pipe to obtain the total outlet pressure,

[0059] Pt_down(M) = Pt_out + Δp_l(M)

[0060] Pt_down(M) represents the downstream total pressure of a section of the main smoke exhaust pipe corresponding to the working smoke machine at the highest layer, and Δp_l(M) represents the pipe resistance loss generated by the fluid flow downstream of the highest layer in the main smoke exhaust pipe,

[0061] Δp_l(M) = λ(M)×0.5ρV(M) 2

[0062] λ(M) represents the coefficient of frictional loss downstream of the highest layer in the main exhaust duct;

[0063] Pt_up(i) = Pt_down(i) + Δp_dir(i)

[0064] Pt_up(i) represents the total upstream pressure of a section of the main exhaust duct corresponding to the working smoke machine on the i-th layer, where i represents any layer among the layers where the working smoke machine is located, Pt_down(i) represents the total downstream pressure of a section of the main exhaust duct corresponding to the working smoke machine on the i-th layer, and Δp_dir(i) represents the direct current loss generated when the fluid in the main exhaust duct flows through the i-th layer.

[0065] Δp_dir(i) = ξ_dir(i) × 0.5ρV(i) 2

[0066] ξ_dir(i) represents the coefficient of direct current loss in a section of the main exhaust duct corresponding to the working smoke machine on the i-th layer, and V(i) represents the average velocity of the fluid downstream of the i-th layer in the main exhaust duct.

[0067] Pt_down(i - 1) = Pt_up(i) + Δp_l(i - 1)

[0068] Pt_down(i - 1) represents the total downstream pressure of a section of the main exhaust duct corresponding to the working smoke machine on the (i - 1)-th layer, and Δp_l(i - 1) represents the pipe resistance loss generated by the fluid flow downstream of the (i - 1)-th layer in the main exhaust duct.

[0069] Δp_l(i - 1) = λ(i - 1) × 0.5ρV(i - 1) 2

[0070] λ(i - 1) represents the coefficient of frictional loss downstream of the (i - 1)-th layer in the main exhaust duct, and V(i - 1) represents the average velocity of the fluid downstream of the (i - 1)-th layer in the main exhaust duct.

[0071] Pt_in(U) = Pt_down(U) + Δp_con(U) + Δp_b(U)

[0072] Pt_in(U) represents the total outlet pressure, Pt_down(U) represents the total downstream pressure of a section of the main exhaust duct corresponding to the working smoke machine at the lowest layer, Δp_con(U) represents the combined flow loss generated when the fluid output by the working smoke machine at the lowest layer flows into the main exhaust duct, and Δp_b(U) represents the pipe resistance loss generated by the fluid flowing in the connecting pipe corresponding to the working smoke machine at the lowest layer.

[0073] Δp_con(U) = ξ_con(U) × 0.5ρv(U) 2

[0074] Δp_b(U) = ξ_b(U) × 0.5ρv(U) 2

[0075] ξ_con(U) represents the combined loss coefficient of the fluid flowing from the working smoke machine at the lowest level into the main exhaust pipe, ξ_b(U) represents the resistance coefficient of the connecting pipe corresponding to the working smoke machine at the lowest level, and v(U) represents the average flow velocity of the fluid in the working smoke machine at the lowest level.

[0076] According to the present invention, a non-transitory computer-readable storage medium is further provided, on which a computer program is stored. When the computer program is executed by a processor, the control method of the central exhaust system as described above is implemented.

[0077] According to the present invention, a computer program product is further provided, including a computer program. When the computer program is executed by a processor, the control method of the central exhaust system as described above is implemented.

[0078] The control of the range hood according to the embodiment of the present invention, by obtaining the air volume adjustment range information, setting a preset air volume based on the air volume adjustment range information, and adjusting the rotation speed of the range hood based on the preset air volume, enables the air volume of the range hood to match the working environment of the range hood, avoids the phenomenon of insufficient exhaust capacity and difficult exhaust of the range hood, and avoids waste of resources caused by redundant exhaust capacity of the range hood. Description of the Drawings

[0079] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0080] Figure 1 is a schematic structural diagram of the central exhaust system provided by the embodiment of the present invention;

[0081] Figure 2 is a schematic diagram of the one-dimensional aerodynamic model of the central exhaust system provided by the embodiment of the present invention;

[0082] Figure 3 is a schematic flowchart of the control method of the range hood provided by the embodiment of the present invention;

[0083] Figure 4 is a partial flowchart of the control method of the range hood provided by the embodiment of the present invention;

[0084] Figure 5 It is a schematic flowchart of the control method of the central smoke exhaust system provided by the embodiment of the present invention;

[0085] Figure 6 It is a partial schematic flowchart of the control method of the central smoke exhaust system provided by the embodiment of the present invention.

[0086] Reference numerals:

[0087] 100, central smoke exhaust system;

[0088] 110, main smoke exhaust duct; 120, range hood; 130, wind cap; 140, connecting pipe; 150, switch valve; 160, control terminal; 170, tee. Detailed implementation manners

[0089] The following further describes the implementation manners of the present invention in detail with reference to the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0090] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0091] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0092] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0093] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0094] The following will be combined with Figures 1-6 to describe the range hood, central smoke exhaust system and their control methods of the present invention. It can be understood that a range hood is a kitchen appliance for purifying the kitchen environment. It can quickly extract the waste generated by the stove combustion and the harmful fumes generated during the cooking process, discharge them outdoors, and at the same time condense and collect the fumes, reduce pollution, purify the air, and have the safety guarantee functions of preventing poison and explosion. In multi-story residential buildings, the kitchen smoke exhaust of the residents shares a common smoke exhaust pipe. Due to the frictional losses and confluence losses generated by the fluid flowing in the common smoke exhaust pipe, the air pressures at the smoke exhaust ends of the range hoods on each floor are inconsistent. The lower the floor where the range hood is located, the greater the air pressure at the smoke exhaust end of the range hood, and the greater the frictional losses and confluence losses of the discharged fluid, and the more difficult the smoke exhaust; on the contrary, the higher the floor where the range hood is located, the smaller the air pressure at the smoke exhaust end of the range hood, and the smaller the frictional losses and confluence losses of the discharged fluid, and the easier the smoke exhaust.

[0095] See Figure 1 as shown Figure 1 is a schematic structural diagram of the central smoke exhaust system 100 provided by the embodiments of the present invention. The arrows in the figure indicate the flow direction of the fluid. The central smoke exhaust system 100 includes a main smoke exhaust pipe 110, a plurality of range hoods 120, a wind cap 130, a plurality of connecting pipes 140, a switching valve 150, and a control terminal 160.

[0096] Specifically, the central smoke exhaust system 100 can be applied to smoke exhaust in high-rise buildings. One end of the main smoke exhaust pipe 110 is provided with a smoke exhaust port. Each range hood 120 is communicated with the main smoke exhaust pipe 110, and a plurality of range hoods 120 are distributed along the length direction of the main smoke exhaust pipe 110. The range hood 120 sucks the indoor air and discharges it into the main smoke exhaust pipe 110. The air in the main smoke exhaust pipe 110 flows towards the smoke exhaust port and then is discharged into the atmosphere. The wind cap 130 covers the smoke exhaust port. The wind cap 130 can block the smoke exhaust port, and moreover, the wind cap 130 can utilize the natural wind force and the air thermal convection caused by the temperature difference between indoors and outdoors to drive the turbine to rotate, thereby discharging the air in the main smoke exhaust pipe 110 by using the centrifugal force and the negative pressure effect.

[0097] The range hood 120 can include a fan, a sensor, and a control module. The fan is rotatable, and the fan rotates to suck the air in the kitchen. The sensor can be connected to the fan, and the sensor can detect parameters such as the current, rotation speed, and air volume of the fan. The control module can be used to receive information. The control module is used to execute the control method of the range hood. The control module is connected to both the fan and the sensor. The control module is connected to the sensor to obtain the parameter information on the sensor; the control module is connected to the fan to adjust the rotation speed or current of the fan.

[0098] The connecting pipe 140 is used to communicate the range hood 120 and the main smoke exhaust pipe 110. One end of the connecting pipe 140 is connected and communicated with the range hood 120, and the other end of the connecting pipe 140 is connected and communicated with the main smoke exhaust pipe 110. Each connecting pipe 140 is connected to the range hood 120 in a one-to-one correspondence. The connecting pipe 140 can be a corrugated pipe. The switching valve 150 is arranged at the connection between the connecting pipe 140 and the main smoke exhaust pipe 110 to control the on-off of the range hood 120 and the main smoke exhaust pipe 110. The switching valve 150 can have two states: an open state and a closed state. The switching valve 150 can be an electromagnetic valve. In some embodiments, the switching valve 150 can be a check valve.

[0099] The switching valve 150 is communicatively connected to the range hood 120. When the range hood 120 is in the on state, the switching valve 150 is in the open state; when the range hood 120 is in the off state, the switching valve 150 is in the closed state. The switching valve 150 can be connected to the control module of the range hood 120. When the range hood 120 is turned on, the control module controls the switching valve 150 to open. When the range hood 120 is turned off, the control module controls the switching valve 150 to close. The switching valve 150 can be a passive check valve, which has a lower cost.

[0100] The control terminal 160 is communicatively connected to each range hood 120. The control terminal 160 can be a mobile terminal, a cloud controller, a control computer, etc. For the convenience of distinction, hereinafter, the range hood 120 in the on state is referred to as the working range hood, and the range hood 120 in the off state is referred to as the standby range hood. The control terminal 160 can adjust the working range hood, for example, adjust the air volume of the range hood 120 to ensure the smoke exhaust capacity of the lower-level range hoods and make the exhaust capacities of the working range hoods on each floor consistent or tend to be consistent, reducing waste of resources.

[0101] By adjusting the air volume through the communication connection between the control terminal 160 and each range hood 120, it is not necessary to set a top fan in the main smoke exhaust duct 110, reducing the installation cost and operation and maintenance cost. During use, users do not need to share the cost of replacing or maintaining the top fan, and the acceptance degree of users is good.

[0102] The interaction process between the control terminal 160 and the range hood 120 can be as follows: The control terminal 160 obtains the status information of each range hood 120. The status information can include information such as the status and parameters of the range hood 120, and calculates parameters such as the air pressure in the main smoke exhaust duct 110 based on the status information. The control terminal 160 can send the calculation result to the range hood 120, and the range hood 120 can be adjusted according to the calculation result, so that the smoke exhaust capacities of the range hoods 120 in the on state in the central smoke exhaust system 100 are consistent, thereby improving the overall smoke exhaust effect. The specific working process and function of the control terminal 160 are reflected in the following embodiments.

[0103] According to the central smoke exhaust system 100 of the embodiment of the present invention, by communicatively connecting the control terminal 160 to each range hood 120 to adjust the working range hood, for example, adjusting the air volume of the range hood 120 to ensure the smoke exhaust capacity of the lower-level range hoods and make the exhaust capacities of the working range hoods on each floor consistent or tend to be consistent, reducing waste of resources.

[0104] See Figure 2 as shown in Figure 2It is a schematic diagram of the one-dimensional pneumatic model of the central smoke exhaust system 100. The one-dimensional pneumatic model of the central smoke exhaust system 100 includes a main smoke exhaust pipe 110, a range hood 120, a wind cap 130, a connecting pipe 140, and a tee pipe 170. Among them, the tee pipe 170 is a tee area formed at the connection of the main smoke exhaust pipe 110 and the connecting pipe 140 to the main smoke exhaust pipe 110. When the air sucked by the range hood 120 flows into the main smoke exhaust pipe 110 from the connecting pipe 140, a confluence loss will occur; when the air in the main smoke exhaust pipe 110 flows through the tee pipe 170, a direct flow loss will occur. The confluence loss coefficient and the direct flow loss coefficient can be obtained by methods such as experiments, simulations, or estimation using empirical formulas. Both the confluence loss coefficient and the direct flow loss coefficient are determined by the ratio of the air volume Q of the range hood 120 to the air volume Q_main in the main smoke exhaust pipe 110, that is, both the confluence loss coefficient and the direct flow loss coefficient are determined by Q / Q_main.

[0105] The expression relationships for the confluence loss coefficient, direct flow loss coefficient, and the pneumatic characteristics of other components of the central smoke exhaust system 100 are as follows:

[0106] Pt_yanji = F1(Q), where Pt_yanji represents the maximum capacity characteristic pressure rise of the range hood 120;

[0107] ξ_b = F2(Q), where ξ_b represents the connecting pipe resistance coefficient;

[0108] ξ_con = F3(Q / Q_main), where ξ_con represents the confluence loss coefficient;

[0109] ξ_dir = F4(Q / Q_main), where ξ_dir represents the direct flow loss coefficient;

[0110] λ = F5(Q_main), where λ represents the friction loss coefficient of the main smoke exhaust pipe 110;

[0111] ξ_fm = F6(Q_main(M)), where ξ_fm represents the wind cap resistance coefficient, and Q_main(M) represents the air volume at the highest layer in the main smoke exhaust pipe 110;

[0112] Q_main(i) represents the total air volume downstream of the i-th layer in the main smoke exhaust pipe 110, and Q(m) represents the air volume of the range hood 120 at the m-th layer.

[0113] In the above expression relationships for the pneumatic characteristics of the central smoke exhaust system 100, when the switch valve is a traditional passive check valve, both the confluence loss coefficient and the direct flow loss coefficient of the central smoke exhaust system 100 are determined by Q / Q_main and Q. At this time, ξ_con = F3(Q / Q_main, Q), and ξ_dir = F4(Q / Q_main, Q).

[0114] See Figure 3 as shown Figure 3 It is a schematic flowchart of the control method of the range hood provided by the embodiment of the present invention. The control method of the range hood may include steps S10 to S40, and the specific steps are as follows:

[0115] S10: Obtain the status information of the range hood 120.

[0116] The status information may include the status of the range hood 120, the floor where the range hood 120 is located, the maximum power of the range hood 120, etc. Among them, the status of the range hood 120 may include the on state and the off state. A sending module may be provided on the range hood 120 for sending the status information of the range hood 120. The receiving end for receiving the status information sent by the range hood 120 may be a mobile terminal, a cloud controller, a control computer, etc. The status information may be used to determine the number of working range hoods in the central exhaust system 100, the floor where the working range hood is located, etc.

[0117] S20: If the range hood 120 is in the on state, obtain the air volume adjustment range information, and the air volume adjustment range information is the adjustable range of the air volume of the range hood.

[0118] When the range hood 120 is in the on state, the fan rotates to suck the air in the kitchen, and the range hood 120 obtains the air volume adjustment information. Among them, the control module of the range hood 120 is used to obtain the air volume adjustment range information. The air volume adjustment information may include the maximum air volume value and the minimum air volume value that can be set by the range hood 120. The range hood 120 adjusts the air volume according to the air volume adjustment range to ensure the exhaust capacity of the range hood 120 and make the air volume of the range hood 120 match the working environment, reducing resource waste. The air volume adjustment information may be obtained from a mobile terminal, a cloud controller, a control computer, etc. When the range hood 120 is in the off state, the range hood 120 maintains its original state.

[0119] S30: Set a preset air volume based on the air volume adjustment range information.

[0120] The range hood 120 sets a preset air volume based on the obtained air volume adjustment range information to match the working environment of the range hood 120 and ensure the exhaust capacity of the range hood 120. Specifically, the control module obtains the adjustment range information, and the control module obtains the adjustment range information from the control module and sets a predetermined air volume based on the air volume adjustment range information. For example, the air volume adjustment range information includes the maximum value and the minimum value of the adjustable air volume, and the control module may set the predetermined air volume to the maximum value of the adjustable air volume.

[0121] S40: Adjust the rotation speed of the range hood 120 based on the preset air volume.

[0122] The range hood 120 adjusts its own rotation speed based on a preset air volume so as to adjust the air volume towards the preset air volume. For example, when the air volume of the range hood 120 is greater than the preset air volume, the rotation speed of the range hood 120 is reduced to decrease the air volume of the range hood 120; when the air volume of the range hood 120 is less than the preset air volume, the rotation speed of the range hood 120 is increased to increase the air volume of the range hood 120; when the air volume of the range hood 120 is equal to the preset air volume, the rotation speed of the range hood 120 may not be adjusted. Specifically, in the range hood 120, the control module adjusts the rotation speed of the fan based on the preset air volume so that the suction air volume of the fan is equal to or approximately equal to the preset air volume. Thus, the smoke exhaust capacity of the range hood 120 matches the working environment, avoiding the phenomenon of insufficient smoke exhaust capacity and difficult smoke exhaust of the range hood 120, and avoiding resource waste caused by redundant smoke exhaust capacity of the range hood 120.

[0123] According to the control method of the range hood according to the embodiment of the present invention, by obtaining air volume adjustment range information, setting a preset air volume based on the air volume adjustment range information, and adjusting the rotation speed of the range hood 120 based on the preset air volume, the air volume of the range hood 120 is matched with the working environment of the range hood 120, avoiding the phenomenon of insufficient smoke exhaust capacity and difficult smoke exhaust of the range hood 120, and avoiding resource waste caused by redundant smoke exhaust capacity of the range hood 120.

[0124] In a multi-story residence, the range hood 120 discharges the cooking fumes in the kitchen into the main smoke exhaust duct 110, and the fumes flowing in the main smoke exhaust duct 110 are subject to resistance, resulting in frictional losses and confluence losses along the way. For the fumes discharged from different floors, the resistance to their flow in the main smoke exhaust duct 110 is also different, so the smoke exhaust capacities of the range hoods 120 on different floors are also different. The fumes discharged from the lower floors have a higher flow resistance, and the range hoods 120 on the lower floors have a greater smoke exhaust resistance, and it is necessary to increase the air volume of the range hoods 120; while the fumes discharged from the upper floors have a lower flow resistance. Blindly increasing the air volume of the range hood 120 cannot successfully solve the problem of difficult smoke exhaust of the range hoods 120 on the lower floors.

[0125] In this application, the range hood 120 obtains the air volume adjustment range, sets a preset air volume based on the air volume adjustment range, and adjusts its own rotation speed based on the preset air volume for air volume adjustment to match the working environment where the range hood 120 is located. In this way, when the number of working range hoods in the building and the floors where the working range hoods are located change, each working range hood can maintain normal smoke exhaust and resource waste can be reduced.

[0126] According to some embodiments of the present invention, the step S30 specifically includes:

[0127] S31: Obtain the gear information of the range hood 120; S32: Divide the air volume adjustment range information into multiple levels of preset air volumes, and correspond each level of preset air volume to the gear of the gear information. For example, if the gear information of the range hood 120 includes three gears, the air volume adjustment range information can be divided into three levels of preset air volumes. Among them, the level with a lower preset air volume value corresponds to the low gear, the level with a relatively larger preset air volume value corresponds to the medium gear, and the level with the highest preset air volume value corresponds to the high gear. When the user is using it, the user can adjust the gear of the range hood 120 within the air volume adjustment range according to the needs.

[0128] In some embodiments, the gear information of the range hood 120 may include the number of adjustable gears of the range hood 120. The air volume adjustment range information includes that the maximum value to which the air volume of the range hood 120 can be adjusted is 800 CMH and the minimum value is 400 CMH. The range hood 120 has three - gear adjustment gears. After the range hood 120 receives the air volume adjustment information, it divides the air volume adjustment range information into three levels of preset air volumes: 400 CMH, 600 CMH, 800 CMH. Then, the preset air volume Q1 corresponding to the first gear of the range hood 120 is 400 CMH, the preset air volume Q2 corresponding to the second gear is 600 CMH, and the preset air volume Q3 corresponding to the third gear is 800 CMH.

[0129] See Figure 4 as shown in Figure 4 It is a partial process schematic diagram of the control method of the range hood, specifically the process schematic diagram of step S40. For the convenience of description, in the figure, Q_real is used to represent the real - time air volume, Q_ys is used to represent the preset air volume, and s is used to represent the preset deviation. Step S40 specifically includes:

[0130] S41: Obtain the real - time current and real - time speed of the range hood 120. Among them, the sensor is connected to the fan to obtain the real - time speed and real - time current of the fan. The sensor can be a Hall sensor, and the sensor can be built into the circuit system of the range hood 120.

[0131] S42: Calculate the real - time air volume of the range hood 120 based on the real - time current and real - time speed. Through the real - time current and real - time speed of the fan checked by the sensor, the real - time air volume is calculated. In the related technology, the real - time air volume is measured by a pressure sensor or a wind sensor exposed in the flue. Compared with the related technology, building the sensor into the circuit system of the range hood 120 has the advantages of being less affected by the external environment, not easily failing, having a high service life, and high reliability.

[0132] S43: Obtain the relative deviation between the real-time air volume and the preset air volume, and adjust the rotation speed of the range hood 120 based on the relative deviation. The relative deviation between the real-time air volume and the preset air volume is: |Q_real - Q_ys| / Q_ys. The control module can calculate the relative deviation between the real-time air volume and the preset air volume of the range hood 120, and adjust the rotation speed of the fan based on the relative deviation, so that the real-time air volume is equal to the preset air volume, or the real-time air volume is approximately equal to the preset air volume within an allowable range. It can be understood that when there are multiple gears of the range hood 120, the preset air volume of the highest gear is used for calculation.

[0133] See Figure 4 As shown, according to some embodiments of the present invention, the steps of obtaining the relative deviation between the real-time air volume and the preset air volume and adjusting the rotation speed of the range hood 120 based on the relative deviation specifically include:

[0134] S44: If the relative deviation is less than or equal to the preset deviation, the rotation speed of the range hood 120 remains unchanged. That is, the real-time air volume can be approximately equal to the preset air volume within a certain range. Figure 4 In which s represents the preset deviation.

[0135] In some embodiments, the steps of obtaining the relative deviation between the real-time air volume and the preset air volume and adjusting the rotation speed of the range hood 120 based on the relative deviation may include:

[0136] S45: If the relative deviation is greater than the preset deviation, obtain the comparison result between the real-time air volume and the preset air volume, and adjust the rotation speed of the range hood 120 based on the comparison result between the real-time air volume and the preset air volume.

[0137] When the relative deviation is greater than the preset deviation, obtain the comparison result between the real-time air volume and the preset air volume to determine the rotation speed adjustment direction of the range hood 120.

[0138] Such as Figure 4 As shown, according to some embodiments of the present invention, if the relative deviation is greater than the preset deviation, the steps of obtaining the comparison result between the real-time air volume and the preset air volume and adjusting the rotation speed of the range hood 120 based on the comparison result between the real-time air volume and the preset air volume specifically include:

[0139] S46: If the real-time air volume is less than the preset air volume, increase the rotation speed of the range hood 120. When the real-time air volume of the range hood 120 is less than the preset air volume, the control module increases the rotation speed of the fan, thereby increasing the real-time air volume of the range hood 120.

[0140] In some embodiments, if the relative deviation is greater than the preset deviation, the steps of obtaining the comparison result between the real-time air volume and the preset air volume and adjusting the rotation speed of the range hood 120 based on the comparison result between the real-time air volume and the preset air volume may include:

[0141] S47: If the real-time air volume is greater than the preset air volume, reduce the rotation speed of the range hood 120. When the real-time air volume of the range hood 120 is greater than the preset air volume, the control module reduces the rotation speed of the fan, thereby reducing the real-time air volume of the range hood 120. When the real-time air volume is equal to the preset air volume, the rotation speed of the range hood 120 can remain unchanged, or the rotation speed of the range hood 120 can be reduced.

[0142] As Figure 4 shown, in the above steps, after adjusting the rotation speed of the range hood 120, return to step S41. The control of the range hood 120 forms a closed-loop feedback control to monitor and adjust the real-time air volume of the range hood 120 in real time, improve the control accuracy, and enable the range hood 120 to maintain normal smoke exhaust.

[0143] See Figure 5 shown, Figure 5 is a schematic flowchart of the control method of the central smoke exhaust system provided by an embodiment of the present invention. The control method of the central smoke exhaust system is applied to the central smoke exhaust system 100 as described above. The control method of the central smoke exhaust system includes:

[0144] S50: Obtain the status information of each range hood 120.

[0145] The control terminal 160 is used to obtain the status information of each range hood 120. The control terminal 160 and the range hood 120 can be wirelessly communicatively connected. The status information may include the status of the range hood 120, the floor where the range hood 120 is located, etc. The control terminal 160 obtains the status information of each range hood 120 to obtain the number of range hoods 120 that are turned on and the floors where they are turned on in the central smoke exhaust system 100.

[0146] S60: Calculate the air volume adjustment range information based on the status information.

[0147] The control terminal 160 calculates the air volume adjustment range information based on the obtained status information of the range hood 120. The obtained air volume adjustment range information can meet the smoke exhaust requirements of the central smoke exhaust system 100, facilitate the adjustment of the range hood 120 in the central smoke exhaust system 100, avoid the situation that the range hood 120 at the lower floors has difficulty exhausting smoke and the range hood 120 at the higher floors wastes resources, and improve the reliability of the central smoke exhaust system 100.

[0148] S70: Send the air volume adjustment range information to the range hood 120.

[0149] The control terminal 160 sends the air volume adjustment range information to the range hood 120 in the on state, that is, the control terminal 160 sends the air volume adjustment information to the working range hood, so that the working range hood adjusts based on the air volume adjustment information, and adjusts the working range hood from the overall dimension of the central exhaust system 100, so that all working range hoods work within their maximum capabilities, with high control reliability, avoiding the situation that the working range hoods located on the lower floors have difficulty in exhausting smoke, and reducing the waste of resources of the working range hoods located on the upper floors.

[0150] Each working range hood obtains the air volume adjustment information from the control terminal 160, sets a preset air volume based on the air volume adjustment information, and adjusts its own rotation speed based on the preset air volume, and performs local closed-loop feedback control through the working range hood, improving the control accuracy and response speed of the working range hood. Improve the response speed and control accuracy of the control of the central exhaust system 100.

[0151] According to the control method of the central exhaust system of the invention embodiment, by obtaining the state information of each range hood 120 and calculating the air volume adjustment range information based on the state information to meet the exhaust requirements of the central exhaust system 100, it is convenient to adjust the range hoods 120 in the central exhaust system 100, avoiding the situation that the range hoods 120 located on the lower floors have difficulty in exhausting smoke and the waste of resources of the range hoods 120 located on the upper floors, and improving the reliability of the central exhaust system 100. By sending the air volume adjustment range information to the range hood 120, so that the working range hood adjusts based on the air volume adjustment information, and adjusts the working range hood from the overall dimension of the central exhaust system 100, so that all working range hoods work within their maximum capabilities, with high control reliability, avoiding the situation that the working range hoods located on the lower floors have difficulty in exhausting smoke, and reducing the waste of resources of the working range hoods located on the upper floors.

[0152] According to some embodiments of the present invention, in the step of calculating the air volume adjustment range information based on the state information, multiple range hoods 120 adopt the same air volume adjustment range information. Thus, the actual exhaust capabilities of each working range hood in the central exhaust system 100 are the same, avoiding the situation that some working range hoods have difficulty in exhausting smoke.

[0153] According to some embodiments of the present invention, the status information includes the number of working range hoods, the floor where the working range hoods are located, and the maximum capacity characteristic pressure rise of the working range hoods. The maximum capacity characteristic pressure rise is the maximum pressure that the air outlet end of the range hood 120 can withstand during normal smoke exhaust. The status information is not limited to this. For example, the status information may further include the number of standby range hoods, the rated power of each range hood 120, etc. In some embodiments, each range hood 120 keeps sending status information to the control terminal 160, that is, both the working range hoods and the standby range hoods send status information to the control terminal 160; or, when the range hood 120 is in the shutdown state, the range hood 120 does not send status information to the control terminal 160, and when the range hood 120 is in the startup state, the range hood 120 sends status information to the control terminal 160 to reduce the power consumption during the standby process of the range hood 120.

[0154] See Figure 6 as shown in Figure 6 It is a partial flowchart of the control method for the central smoke exhaust system, specifically the flowchart of step S60. For ease of description, in the figure, Pt_in(U) represents the total outlet pressure, and Pt_yanji(U) represents the maximum capacity characteristic pressure rise of the working range hood at the bottommost layer.

[0155] According to some embodiments of the present invention, the step of calculating the air volume adjustment range information based on the status information specifically includes:

[0156] S61: Set the initial air volume value of the working range hood.

[0157] The control terminal 160 obtains the status information of each range hood 120 to determine the status of each range hood 120, and the control terminal 160 sets the initial air volume value of the working range hood. When the user turns on the range hood 120, the range hood 120 sends its own status information to the control terminal 160, and after the control terminal 160 detects that the range hood 120 is in the startup state, it sets the initial air volume value of the range hood 120. The initial air volume value can be 700 CMH - 1000 CMH.

[0158] S62: Set the initial value of the process air volume value of the working range hood to be equal to the initial air volume value. The process air volume value is used to calculate the air volume adjustment range. The process air volume value is a virtual value and has no direct impact on the working range hood, and the process air volume value changes during the process of calculating the air volume adjustment range.

[0159] S62: Calculate the total outlet pressure of the working range hood at the lowest layer. The total outlet pressure is the wind pressure at the connection point of the connecting pipe 140 and the main smoke exhaust pipe 110.

[0160] It can be understood that in the central smoke exhaust system 100, the air pressure at the connection between the connecting pipe 140 connected to the working smoke machine and the main smoke exhaust pipe 110 is the air pressure at the outlet end of the working smoke machine. The air pressure at the outlet end of the working smoke machine increases as the floor where the working smoke machine is located decreases. Among all the working smoke machines, the air pressure at the outlet end of the working smoke machine at the lowest floor is the largest, and the smoke exhaust pressure of the working smoke machine at the lowest floor is the largest. The air pressure at the outlet end of the working smoke machine at the lowest floor is the total outlet pressure.

[0161] S63: Obtain the comparison result between the total outlet pressure and the maximum capacity characteristic pressure rise of the working smoke machine at the lowest floor. Compare the air pressure at the outlet end of the working smoke machine at the lowest floor with its own maximum capacity characteristic pressure rise, and use this comparison result as a reference basis to calculate the air volume adjustment range information, so as to ensure that each working smoke machine in the central smoke exhaust system 100 can exhaust smoke normally when the air volume is set within the air volume adjustment range information.

[0162] According to some embodiments of the present invention, the step of obtaining the comparison result between the total outlet pressure and the maximum capacity characteristic pressure rise of the working smoke machine at the lowest floor specifically includes:

[0163] S65: If the total outlet pressure is less than or equal to the maximum capacity characteristic pressure rise of the working smoke machine at the lowest floor, the maximum value of the air volume adjustment range information is taken as the process air volume value. The minimum value of the air volume adjustment range information can be obtained according to the characteristics of the central smoke exhaust system 100. The minimum value of the air volume adjustment range information can be taken as 300 CMH - 500 CMH. For example, the minimum value of the air volume adjustment range information can be 300 CMH, 400 CMH, or 500 CMH.

[0164] As Figure 6 shown, in some embodiments, the step of obtaining the comparison result between the total outlet pressure and the maximum capacity characteristic pressure rise of the working smoke machine at the lowest floor may include:

[0165] S66: If the total outlet pressure is greater than the maximum capacity characteristic pressure rise of the working smoke machine at the lowest floor, reduce the process air volume value, and calculate the total outlet pressure of the working smoke machine at the lowest floor to obtain the comparison result between the total outlet pressure and the maximum capacity characteristic pressure rise of the working smoke machine at the lowest floor. The reduction amount when reducing the process air volume value can be 5 - 100 CMH. In this way, a cyclic control process is formed, and the process air volume value is reduced through the cyclic control process, so that the total outlet pressure is reduced to be less than or equal to the maximum capacity characteristic pressure rise of the working smoke machine at the lowest floor.

[0166] In some embodiments, in the step of obtaining the comparison result between the total outlet pressure and the maximum capacity characteristic pressure rise of the working steam turbine at the lowest layer, the comparison relationship between the total outlet pressure and the maximum capacity characteristic pressure rise of the working steam turbine at the lowest layer can be Pt_in(U) ≤ (1 - α)Pt_yanji(U), where α is the reserved redundancy to improve the reliability of control. α can take a value of 1 - 10%. The larger α is, the greater the reserved redundancy of the system and the higher the reliability.

[0167] According to some embodiments of the present invention, the steps of calculating the total outlet pressure of the working steam turbine at the lowest layer, where the total outlet pressure is the wind pressure at the connection between the connecting pipe 140 and the main exhaust pipe 110, specifically include:

[0168] Calculating the total pressure at the connection between the wind cap 130 and the main exhaust pipe 110,

[0169] Pt_out = 0.5ρV9M) 2 +Δp_fm

[0170] where Pt_out represents the total pressure at the connection between the wind cap 130 and the main exhaust pipe 110, Δp_fm represents the resistance loss generated by the fluid passing through the wind cap 130, and V(M) represents the average flow velocity of the fluid downstream of the highest layer in the main exhaust pipe 110;

[0171] Δp_fm = ξ_fm × 0.5ρV(M) 2

[0172] where ξ_fm represents the resistance coefficient of the wind cap 130 and ρ represents the fluid density.

[0173] Performing iterative calculation on the total pressure at the position of each working steam turbine layer in the main exhaust pipe 110 to obtain the total outlet pressure,

[0174] Pt_down(M) = Pt_out + Δp_l(M)

[0175] Pt_down(M) represents the downstream total pressure of a section of the main exhaust pipe 110 corresponding to the highest layer working steam turbine, and Δp_l(M) represents the pipe resistance loss generated by the fluid flow downstream of the highest layer in the main exhaust pipe 110,

[0176] Δp_l(M) = λ(M) × 0.5ρV(M) 2

[0177] λ(M) represents the friction loss coefficient downstream of the highest layer in the main exhaust pipe 110, that is, the working steam turbine at the highest layer;

[0178] Pt_up(i) = Pt_down(i) + Δp_dir(i)

[0179] Pt_up(i) represents the upstream total pressure of a section of the main exhaust duct 110 corresponding to the working smoke machine on the i-th floor, where i represents any one of the floors where the working smoke machine is located. Pt_down(i) represents the downstream total pressure of a section of the main exhaust duct 110 corresponding to the working smoke machine on the i-th floor. Δp_dir(i) represents the direct current loss generated when the fluid in the main exhaust duct 110 flows through the i-th floor.

[0180] Δp_dir(i) = ξ_dir(i) × 0.5ρV(i) 2

[0181] ξ_dir(i) represents the direct current loss coefficient in a section of the main exhaust duct 110 corresponding to the working smoke machine on the i-th floor, and V(i) represents the average flow velocity of the fluid downstream of the i-th floor in the main exhaust duct 110.

[0182] Pt_down(i - 1) = Pt_up(i) + Δp_l(i - 1)

[0183] Pt_down(i - 1) represents the downstream total pressure of a section of the main exhaust duct 110 corresponding to the working smoke machine on the (i - 1)-th floor, and Δp_l(i - 1) represents the pipe resistance loss generated by the fluid flow downstream of the (i - 1)-th floor in the main exhaust duct 110.

[0184] Δp_l(i - 1) = λ(i - 1) × 0.5ρV(i - 1) 2

[0185] λ(i - 1) represents the friction loss coefficient downstream of the (i - 1)-th floor in the main exhaust duct 110, and V(i - 1) represents the average flow velocity of the fluid downstream of the (i - 1)-th floor in the main exhaust duct 110.

[0186] Pt_in(U) = Pt_down(U) + Δp_con(U) + Δp_b(U)

[0187] Pt_in(U) represents the outlet total pressure, Pt_down(U) represents the downstream total pressure of a section of the main exhaust duct 110 corresponding to the working smoke machine located on the lowest floor, Δp_con(U) represents the combined flow loss generated when the fluid output by the working smoke machine on the lowest floor flows into the main exhaust duct 110, and Δp_b(U) represents the pipe resistance loss generated by the fluid flowing in the connecting pipe 140 corresponding to the working smoke machine on the lowest floor.

[0188] Δp_con(U) = ξ_con(U) × 0.5ρv(U) 2

[0189] Δp_b(U) = ξ_b(U) × 0.5ρv(U) 2

[0190] ξ_con(U) represents the combined loss coefficient of the fluid flowing from the working fume extractor at the lowest level into the main exhaust duct 110, ξ_b(U) represents the resistance coefficient of the connecting pipe 140 corresponding to the working fume extractor at the lowest level, and v(U) represents the average flow velocity of the fluid in the working fume extractor at the lowest level.

[0191] A specific embodiment is provided below for easy understanding of the technical solution of the present application:

[0192] In the central exhaust system 100, a random number and random floors of the range hoods 120 are started, the range hoods 120 are in the on state, the switching valves 150 are opened, and the control module sends the status information of the range hoods 120 to the control terminal 160.

[0193] The control terminal 160 obtains the status information of each range hood 120 to obtain the number of working fume extractors in the central exhaust system 100, the floors where the working fume extractors are located, and the maximum capacity characteristic pressure rise of the working fume extractors.

[0194] The control terminal 160 sets the initial air volume value of the working fume extractor based on the status information. For example, the initial air volume of all working fume extractors can be set to 700 CMH. Then, for the convenience of calculating the air volume adjustment range information, the initial value of the process air volume value of the working fume extractor is set equal to the initial air volume value. During the calculation of the air volume adjustment range information, the process air volume value changes, but the process air volume value does not affect the real-time air volume of the working fume extractor. Next, the control terminal 160 calculates the outlet total pressure through the above formula. Finally, the calculated outlet total pressure is compared with the maximum capacity characteristic pressure rise of the working fume extractor at the lowest level. When the outlet total pressure is less than or equal to the maximum capacity characteristic pressure rise of the working fume extractor at the lowest level, the maximum value of the air volume adjustment range information is taken as the process air volume value, and the minimum value of the air volume adjustment range information can be set to 400 CMH; when the outlet total pressure is greater than the maximum capacity characteristic pressure rise of the working fume extractor at the lowest level, the process air volume value is reduced, and the outlet total pressure of the working fume extractor at the lowest level is calculated. The calculated outlet total pressure is compared with the maximum capacity characteristic pressure rise of the working fume extractor at the lowest level, and the process air volume value is adjusted based on the comparison result between the outlet total pressure and the working fume extractor at the lowest level. The above process is repeated until the outlet total pressure is less than or equal to the maximum capacity characteristic pressure rise of the working fume extractor at the lowest level, so as to obtain the maximum value of the air volume adjustment range information.

[0195] The control terminal 160 sends the air volume adjustment range information to the working fume extractor. In this embodiment, the maximum value of the air volume adjustment range information is 800 CMH, and the minimum value is 400 CMH.

[0196] The control module of the working fume hood obtains the air volume adjustment information. The control module of the working fume hood obtains the air volume adjustment range information from the control module and divides the air volume adjustment range information into three levels of preset air volumes, each level of preset air volume being 400 CMH, 600 CMH, and 800 CMH respectively. Among them, the preset air volume corresponding to the first gear of the working fume hood is 400 CMH, the preset air volume corresponding to the second gear is 600 CMH, and the preset air volume corresponding to the third gear is 800 CMH.

[0197] When the user adjusts the gear of the working fume hood to the second gear, the preset air volume is 600 CMH. The sensor detects the real-time current and real-time speed of the fan and sends the real-time current and real-time speed to the control module. The control module calculates the real-time air volume of the working fume hood, calculates the relative deviation between the real-time air volume and the preset air volume, and compares the relative deviation with the preset deviation. When the relative deviation is less than or equal to the preset deviation, the speed of the fan remains unchanged, and the working fume hood can exhaust smoke normally; when the relative deviation is greater than the preset deviation, compare the magnitudes of the real-time air volume and the preset air volume. When the real-time air volume is less than the preset air volume, increase the speed of the fan, increase the air volume of the working fume hood, and improve the smoke exhaust capacity of the working fume hood. When the real-time air volume is greater than the preset air volume, decrease the speed of the fan, decrease the air volume of the working fume hood, and reduce resource consumption.

[0198] Essentially, or the part that makes a contribution to the related technology, or the part of this technical solution of the present invention can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. And the aforementioned storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs and other various media that can store program codes.

[0199] On the other hand, the embodiments of the present invention disclose a computer program product. The computer program product includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the control method of the central smoke exhaust system provided by the above-mentioned method embodiments.

[0200] On yet another aspect, the embodiments of the present invention further provide a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the control method of the central smoke exhaust system provided by the above-mentioned embodiments. The steps and principles have been introduced in detail in the above method and will not be repeated here.

[0201] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0202] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution or the part that contributes to the related technology can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0203] Finally, it should be noted that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that various combinations, modifications, or equivalent replacements of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should all be covered by the scope of the claims of the present invention.

Claims

1. A control method for an oil fume extractor, characterized in that, it includes: Obtain the status information of the oil fume extractor; If the oil fume extractor is in the on state, obtain the air volume adjustment range information, and the air volume adjustment range information is the adjustable range of the air volume of the oil fume extractor; Set a preset air volume based on the air volume adjustment range information; Adjust the rotation speed of the oil fume extractor based on the preset air volume.

2. The control method for an oil fume extractor according to claim 1, characterized in that, The step of setting a preset air volume based on the air volume adjustment range information includes: Obtain the gear information of the oil fume extractor; Divide the air volume adjustment range information into multiple levels of preset air volumes, and correspond each level of the preset air volume to the gear of the gear information.

3. The control method for an oil fume extractor according to claim 1, characterized in that, The step of adjusting the rotation speed of the oil fume extractor based on the preset air volume includes: Obtain the real-time current and real-time rotation speed of the oil fume extractor; Calculate the real-time air volume of the oil fume extractor based on the real-time current and the real-time rotation speed; Obtain the relative deviation between the real-time air volume and the preset air volume, and adjust the rotation speed of the oil fume extractor based on the relative deviation.

4. The control method for an oil fume extractor according to claim 3, characterized in that, The step of obtaining the relative deviation between the real-time air volume and the preset air volume, and adjusting the rotation speed of the oil fume extractor based on the relative deviation includes: If the relative deviation is less than or equal to the preset deviation, the rotation speed of the oil fume extractor remains unchanged; Or, if the relative deviation is greater than the preset deviation, obtain the comparison result between the real-time air volume and the preset air volume, and adjust the rotation speed of the oil fume extractor based on the comparison result between the real-time air volume and the preset air volume.

5. The control method for an oil fume extractor according to claim 4, characterized in that, The step of, if the relative deviation is greater than the preset deviation, obtaining the comparison result between the real-time air volume and the preset air volume, and adjusting the rotation speed of the oil fume extractor based on the comparison result between the real-time air volume and the preset air volume specifically includes: If the real-time air volume is less than the preset air volume, increase the rotation speed of the oil fume extractor; Or if the real-time air volume is greater than the preset air volume, decrease the rotation speed of the oil fume extractor.

6. An oil fume extractor, characterized in that, the oil fume extractor includes: A fan, the fan is rotatable; A sensor, the sensor is connected to the fan, and the sensor is used to detect the real-time rotation speed and real-time current of the fan; A control module, the control module is connected to both the fan and the sensor, and the control module is used to execute the control method for the oil fume extractor according to any one of claims 1-5.

7. A central smoke exhaust system, characterized in that, it includes: A main smoke exhaust pipe, one end of the main smoke exhaust pipe is provided with a smoke exhaust port; Multiple oil fume extractors, the oil fume extractors are the oil fume extractors described in claim 6, each oil fume extractor is communicated with the main smoke exhaust pipe, and the multiple oil fume extractors are distributed along the length direction of the main smoke exhaust pipe; A wind cap, the wind cap covers the smoke exhaust port; A plurality of connecting pipes, one end of each connecting pipe is connected and communicated with the range hood, and the other end of each connecting pipe is connected and communicated with the main exhaust pipe, and each connecting pipe is connected to the range hood in a one-to-one correspondence; A switching valve, which is arranged at the connection between the connecting pipe and the main exhaust pipe to control the on-off of the range hood and the main exhaust pipe; A control terminal, which is communicatively connected to each range hood.

8. A control method for a central exhaust system, Characterized in that, Applied to the central exhaust system according to claim 7, the control method of the central exhaust system includes: Obtaining the status information of each range hood; Calculating the air volume adjustment range information based on the status information; Sending the air volume adjustment range information to the range hood.

9. The control method for the central exhaust system according to claim 8, Characterized in that, In the step of calculating the air volume adjustment range information based on the status information, the same air volume adjustment range information is adopted for a plurality of range hoods.

10. The control method for the central exhaust system according to claim 9, Characterized in that, Among a plurality of range hoods, the range hood in the on state is the working range hood, and the range hood in the off state is the standby range hood; The status information includes the number of working range hoods, the floors where the working range hoods are located, and the maximum capacity characteristic pressure rise of the working range hoods.

11. The control method for the central exhaust system according to claim 10, Characterized in that, The step of calculating the air volume adjustment range information based on the status information includes: Setting the initial air volume value of the working range hood; Setting the initial value of the process air volume value of the working range hood to be equal to the initial air volume value; Calculating the total outlet pressure of the working range hood at the lowest floor, and the total outlet pressure is the wind pressure at the connection between the connecting pipe and the main exhaust pipe; Obtaining the comparison result between the total outlet pressure and the maximum capacity characteristic pressure rise of the working range hood at the lowest floor.

12. The control method for the central exhaust system according to claim 11, Characterized in that, The step of obtaining the comparison result between the total outlet pressure and the maximum capacity characteristic pressure rise of the working range hood at the lowest floor specifically includes: If the total outlet pressure is less than or equal to the maximum capacity characteristic pressure rise of the working range hood at the lowest floor, the maximum value of the air volume adjustment range information is taken as the process air volume value; Or, if the total outlet pressure is greater than the maximum capacity characteristic pressure rise of the working range hood at the lowest floor, reducing the process air volume value, calculating the total outlet pressure of the working range hood at the lowest floor, and obtaining the comparison result between the total outlet pressure and the maximum capacity characteristic pressure rise of the working range hood at the lowest floor.

13. The control method for the central exhaust system according to claim 11, Characterized in that, The step of calculating the total outlet pressure of the working range hood at the lowest floor, and the total outlet pressure is the wind pressure at the connection between the connecting pipe and the main exhaust pipe specifically includes: Calculating the total pressure at the connection between the wind cap and the main exhaust pipe, Pt_out = 0.5ρV9M) 2 + Δp_fm Among them, Pt_out represents the total pressure at the connection between the wind cap and the main exhaust pipe, Δp_fm represents the resistance loss generated by the fluid passing through the wind cap, and V(M) represents the average flow velocity of the fluid downstream of the highest layer in the main exhaust pipe; Δp_fm = ξ_fm × 0.5ρV(M) 2 Among them, ξ_fm represents the wind cap resistance coefficient, and ρ represents the fluid density; The outlet total pressure is obtained by performing iterative calculations on the total pressure at the working smoke machine corresponding to each layer in the main exhaust pipe. Pt_down(M) = Pt_out + Δp_l(M) Pt_down(M) represents the total downstream pressure of the section of the main exhaust duct corresponding to the working smoke machine on the highest floor, and Δp_l(M) represents the pipe resistance loss generated by the fluid flow downstream on the highest floor in the main exhaust duct. Δp_l(M) = λ(M) × 0.5ρV(M) 2 λ(M) represents the friction loss coefficient downstream of the highest layer in the main exhaust pipe; Pt_up(i) = Pt_down(i) + Δp_dir(i) Pt_up(i) represents the upstream total pressure of a section of the main exhaust pipe corresponding to the working smoke machine at the i-th layer, where i represents any layer in the number of layers where the working smoke machine is located, Pt_down(i) represents the downstream total pressure of a section of the main exhaust pipe corresponding to the working smoke machine at the i-th layer, and Δp_dir(i) represents the direct current loss generated when the fluid in the main exhaust pipe flows through the i-th layer. Δp_dir(i) = ξ_dir(i) × 0.5ρV(i) 2 ξ_dir(i) represents the direct current loss coefficient in a section of the main exhaust pipe corresponding to the working smoke machine at the i-th layer, and V(i) represents the average flow velocity of the fluid downstream of the i-th layer in the main exhaust pipe; Pt_down(i - 1) = Pt_up(i) + Δp_l(i - 1) Pt_down(i - 1) represents the downstream total pressure of a section of the main exhaust pipe corresponding to the working smoke machine at the (i - 1)-th layer, and Δp_l(i - 1) represents the pipe resistance loss generated by the fluid flow downstream of the (i - 1)-th layer in the main exhaust pipe. Δp_l(i - 1) = λ(i - 1) × 0.5ρV(i - 1) 2 λ(i - 1) represents the friction loss coefficient downstream of the (i - 1)-th layer in the main exhaust pipe, and V(i - 1) represents the average flow velocity of the fluid downstream of the (i - 1)-th layer in the main exhaust pipe; Pt_in(U) = Pt_down(U) + Δp_con(U) + Δp_b(U) Pt_in(U) represents the outlet total pressure, Pt_down(U) represents the downstream total pressure of a section of the main exhaust pipe corresponding to the working smoke machine located at the lowest layer, Δp_con(U) represents the confluence loss generated when the fluid output by the working smoke machine at the lowest layer flows into the main exhaust pipe, and Δp_b(U) represents the pipe resistance loss generated by the fluid flowing in the connecting pipe corresponding to the working smoke machine at the lowest layer. Δp_con(U) = ξ_con(U) × 0.5ρv(U) 2 Δp_b(U) = ξ_b(U) × 0.5ρv(U) 2 ξ_con(U) represents the confluence loss coefficient when the fluid flows from the working smoke machine at the lowest layer into the main exhaust pipe, ξ_b(U) represents the resistance coefficient of the connecting pipe corresponding to the working smoke machine at the lowest layer, and v(U) represents the average flow velocity of the fluid in the working smoke machine at the lowest layer.

14. A non-transitory computer-readable storage medium, on which a computer program is stored. Characterized in that When the computer program is executed by a processor, it implements the control method of the central exhaust system according to any one of claims 8 - 13.

15. A computer program product, including a computer program. Characterized in that When the computer program is executed by a processor, it implements the control method of the central smoke exhaust system according to any one of claims 8-13.

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