A method for selecting a commercial smoke exhaust system

Abstract

The invention discloses a method for selecting a commercial smoke exhaust system, comprising the selection of a purification component and a fan system; the selection of the purification component comprises the following steps: S1) determining basic purification parameters: a) cooking mode Pi; b) purification efficiency configuration Lj; c) scale Yw; S2) obtaining a recommended purification component layout Hm=F(Pi, Lj, Yw), where m represents the number corresponding to the classification of the purification component layout; the selection of the fan system comprises the following steps: S1) determining basic air volume parameters: a) the number of stoves Z1; b) the total horizontal projection area A1 of the exhaust hood on the stove; c) the number of cooking modules Z2; d) the horizontal projection area A2 of the cooking module; e) the caliber of the pot, which is recorded as G; S2) calculating the total projection area A0; S3) obtaining a recommended exhaust volume Q=Q0*A0, where Q0 is the reference emission of a single stove; S4) calculating the performance parameters of the fan system according to the wind resistance P and the exhaust volume Q of the smoke exhaust system, and determining the model of the fan system.

Description

Technical Field

[0001] The invention relates to a method for selecting a commercial smoke exhaust system. Background Art

[0002] Due to the unique characteristics of Chinese cooking, which is stir-frying with fierce fire, a large amount of oil smoke is produced. In order to improve the oil smoke absorption effect and meet the requirements of environmental protection laws and regulations, commercial kitchens, such as catering units, mostly use long flues and place high-power fans on the roof or other locations away from residential areas to exhaust the oil smoke. However, after long-term use, a large amount of oil pollution accumulates inside the range hood and in the air duct, which reduces the performance and the oil smoke absorption effect. In actual applications, there is often a phenomenon of large fans with small equipment (the flue gas flow rate is too fast and the residence time is short, resulting in a decrease in purification efficiency). At the same time, the concentration and characteristics of the oil smoke emission sources of catering units with different cuisines vary greatly.

[0003] In order to solve the problem of high energy consumption, the currently commonly used technology is to increase the diameter of the air duct or reduce the power of the exhaust fan. This approach has the following disadvantages:

[0004] (1) Increasing the diameter of the air duct is limited by space, the air duct structure is complex, occupies a large area, and the effect is quite limited;

[0005] (2) Reducing the power of the exhaust fan and the wind speed will reduce the fume extraction effect when the amount of oil smoke is large, resulting in more losses than gains;

[0006] (3) Both methods are difficult to solve the problem of high emission noise and nuisance to residents.

[0007] Basically, the same design is used for different cuisines, which will lead to energy waste and increased costs. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a method for selecting a commercial smoke exhaust system in view of the deficiencies in the above-mentioned prior art, so as to optimize energy consumption and cost through differentiated design.

[0009] The technical solution adopted by the present invention to solve the above technical problems is: a method for selecting a commercial smoke exhaust system, the commercial smoke exhaust system comprises an exhaust hood arranged above a stove, a purification component and a fan system are arranged in the exhaust hood, a stove head and a pot placed on the stove head are arranged on the top of the stove, and a cooking module that generates oil smoke or steam and is sucked into the exhaust hood is arranged in the stove; the characteristic is that: the selection method includes the selection of the purification component and the fan system;

[0010] The selection of the purification component includes the following steps:

[0011] S1) Determine the basic purification parameters:

[0012] a) Cooking method Pi, i is the number corresponding to the classification of the cooking method;

[0013] b) Purification efficiency configuration Lj: j is the number corresponding to the classification of the expected purification efficiency;

[0014] c) Scale Yw: w represents the number corresponding to the scale classification of the commercial kitchen where the exhaust system is located;

[0015] S2) obtaining a recommended purification component layout Hm=F(Pi, Lj, Yw), where m represents the number corresponding to the classification of the purification component layout, and the relationship between Hm and Pi, Lj and Yw is determined and stored in advance through experiments or empirical values;

[0016] The selection of the fan system includes the following steps:

[0017] S1) Determine the basic parameters of air volume:

[0018] a) The number of stoves, denoted as Z1;

[0019] b) The total horizontal projection area of ​​the exhaust hood on the stove, denoted as A1;

[0020] c) The number of cooking modules, denoted as Z2;

[0021] d) The horizontal projection area of ​​the cooking module, denoted as A2;

[0022] e) The diameter of the pot, denoted as G;

[0023] S2) calculating the total projected area A0 based on Z1, A1, Z2 and A2;

[0024] S3) obtaining the recommended exhaust volume Q=Q0*A0, wherein Q0 is the reference exhaust volume of a single stove;

[0025] S4) calculating the performance parameters of the fan system according to the wind resistance P and exhaust volume Q of the smoke exhaust system after the layout of the purification components is determined, and determining the model of the fan system.

[0026] Preferably, in the step S1) of selecting the purification component, the cooking methods are distinguished by the concentration of oil fume emissions and the concentration of non-methane total hydrocarbons.

[0027] Preferably, in step S1) of selecting the purification component, the size is determined by the number of burners.

[0028] Preferably, in the step S2) of selecting the purification component, the layout of the purification component includes the selection of the type of purification module, the selection of the number of purification modules and the selection of the position of the purification module.

[0029] Preferably, in order to select a suitable projection area for different pot sizes to obtain the corresponding preferred exhaust volume, in the fan system selection step S2), first determine whether G is less than G0, if yes, proceed to step S2.1), if not, proceed to step S2.2); G0 is a preset pot size threshold:

[0030] S2.1) Calculate the total projected area A0, A0 = MAX(A1, Z1*A 标1 )+MAX(A2,Z2*A 标2 );

[0031] S2.2) Calculate the total projected area A0, A0 = MAX(Z1*A 标3 )+MAX(A2,Z2*A 标2 );

[0032] Among them, A 标1 and A 标3 The standard value of the exhaust hood stove projection corresponding to a single reference stove head, and meets A 标3 >A 标1 , A 标2 This is the projection standard value of a single cooking module.

[0033] Preferably, in order to accurately obtain the smoke exhaust resistance of the entire system, the commercial smoke exhaust system also includes a smoke exhaust pipe, wind resistance P = (L*f1+S*f2+H) / Q 2 , where f1 is the pressure difference per unit distance of the exhaust pipe, f2 is the pressure difference of the elbow of a single exhaust pipe, H is the pressure difference under the current purification component layout, L is the length of the exhaust pipe, and S is the number of elbows in the exhaust pipe.

[0034] Preferably, the performance parameters of the fan system include air volume Q 风 , wind pressure P 风 , power W and speed N.

[0035] Preferably, in order to make the fan system performance slightly redundant to meet the demand, Q 风 =Q*n2;P 风 =P*n3;W=Q 风 *P 风 *n1 / (3600*η1*η2*1000), N=F(Q, P), the function F(Q, P) is obtained through experiments, n1, n2 and n3 are redundancy coefficients, all greater than 1 and less than 1.5.

[0036] Preferably, in order to improve the fume extraction effect, the selection method also includes the selection of an air supply system, and the air supply is achieved by mechanical air supply and / or natural air supply, so that the final air supply volume Q 补风The ratio to Q is between 0.8 and 1.

[0037] Compared with the prior art, the advantages of the present invention are: taking into account the stove projection area, the number of stoves, the cooking module projection area and the number of cooking modules, carrying out the optimal design of the air volume, and finding the best matching air volume, which not only ensures the oil fume absorption effect but also achieves energy saving; the selection of the purification component is selected according to different cooking methods, purification requirements and differences brought about by scale, so as to maximize the purification effect and save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the application state of a commercial smoke exhaust system according to an embodiment of the present invention;

[0039] Figure 2 It is a cross-sectional view of a commercial smoke exhaust system according to an embodiment of the invention (the smoke exhaust pipe and the stove are hidden). DETAILED DESCRIPTION

[0040] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing 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. Since the embodiments disclosed in the present invention can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0042] See also Figure 1 and Figure 2 A commercial smoke exhaust system includes an exhaust hood 1, in which a purification component and a fan system 3 are arranged. The exhaust hood 1 is installed above a stove 100. A stove head 101 is arranged on the top of the stove 100, and a pot 200 is placed on the stove head 101. A cooking module 300 such as an oven and a steamer can also be arranged in the stove 100, which will generate oil smoke, steam, etc. during cooking and be sucked into the exhaust hood 1.

[0043] The purification component usually includes a multi-stage purification module for filtering and purifying oil fume particles, adsorbing VOCs in oil fume, etc. For an optional implementation, please refer to the applicant's prior application with application number 201910354531.3, including a first-stage purification module 41, a second-stage purification module 42, a third-stage purification module 43 and a fourth-stage purification module 44 along the oil fume flow path, from downstream to upstream. The first-stage purification module 41 adopts a smoke guide plate or a filter with a larger aperture, the second-stage purification module 42 adopts a rotating mesh disk or a double-layer filter, the third-stage purification module 43 adopts an electrostatic purification device, a HEPA filter, etc., and the fourth-stage purification module 44 adopts a high-efficiency porous activated carbon to adsorb VOCs.

[0044] The method for selecting a commercial smoke exhaust system of the present invention includes selecting a fan system 3 and a purification component to achieve a differentiated optimization design.

[0045] Among them, for the selection of fan system 3, the traditional air volume optimization design method is generally based on the number of stoves (the exhaust volume of a single stove is 2000m 3 / h) for selection, but in actual operation, due to the large difference in pot area, stove projection area, etc. between large pot stoves and small frying stoves, the present invention proposes to take into account the stove projection area and the number of stove heads and carry out the optimal design of air volume, thereby finding the best matching air volume, which can ensure the oil fume absorption effect and achieve energy saving. Specifically, it includes the following steps:

[0046] S1) Determine the basic parameters of air volume:

[0047] a) The number of stove heads 101 is Z1;

[0048] b) The total horizontal projection area of ​​the exhaust hood 1 on the stove 100 is A1, and the projection is a rectangle, A1=a*b, where a is the length of the projection of the exhaust hood 1 (the dimension in the left-right direction), and b is the width of the projection of the exhaust hood 1 (the dimension in the front-back direction);

[0049] c) The number of cooking modules 300 such as ovens and steamers is Z2;

[0050] d) The horizontal projection area of ​​the cooking module 300 of the oven and steamer is A2. Preferably, the projection here is the projection of the outermost wall of the cooking module 300. Such a cooking module 300 is usually a cuboid, so the projection is usually also a rectangle;

[0051] e) The size of the pot 200 is G. In a commercial kitchen, the size of the pot 200 is determined by the size of the stove 101. That is, once the stove 100 (stove 101) is determined, the size of the pot 200 is determined. G represents the diameter of the pot 200.

[0052] S2) Determine whether G is less than G0. If yes, proceed to step 2.1). If not, proceed to step 2.2). Wherein, G0 is a preset size threshold of the pot 200. If it exceeds the threshold, it means that the stove head 101 is larger and the amount of oil smoke generated is larger. If it does not exceed the threshold, it means that the stove head 101 is smaller and the amount of oil smoke generated is smaller.

[0053] S2.1) Calculate the total projected area A0, A0 = MAX(A1, Z1*A 标1 )+MAX(A2,Z2*A 标2 );

[0054] S2.2) Calculate the total projected area A0, A0 = MAX(Z1*A 标3 )+MAX(A2,Z2*A 标2 );

[0055] Among them, A 标1 and A 标3 The standard value of the exhaust hood stove projection corresponding to a single reference stove head, and meets A 标3 >A 标1 , A 标2 It is the projection standard value of a single cooking module 300;

[0056] According to the National Environmental Protection GB18483-2001 "Catering Industry Fume Emission Standard", the exhaust hood projection area of ​​each standard stove head is 1.1m 2 , considering the design redundancy and according to the experimental simulation results, in this embodiment, A 标1 1.2*1.0(m 2 ), A 标3 1.4*1.0(m 2 );A 标2 The sizes of the cooking modules 300 of different models on the market can be obtained by referring to them. For example, in this embodiment, A 标2 0.8*0.8(m 2 );

[0057] S3) obtains the recommended exhaust volume Q = Q0 * A0, where Q0 is the baseline emission of a single stove 101. According to the National Environmental Protection GB18483-2001 "Catering Fume Emission Standard", the Q0 of large, medium and small catering units is 2000m 3 According to Q and the selection of the purification components to be described in detail below, the selection of the fan system 3 can be finally obtained.

[0058] The selection of traditional purification components is mainly based on electrostatic technology, without considering the differences in cooking methods, purification requirements and scale (air volume). The current emission status of different cooking methods: the average concentration of Sichuan and Hunan cuisine fume emissions is twice that of Cantonese cuisine (home cooking), and the average concentration of non-methane total hydrocarbons is three times that of Cantonese cuisine (home cooking); the concentration of Sichuan and Hunan cuisine fume emissions can be as high as 23.75mg / m 3 , is the standard emission concentration of 10mg / m 3 The maximum non-methane total hydrocarbon emission concentration reached 100mg / m3, which is 2.3 times the limit of 10mg / m 3 10 times of that.

[0059] Taking a small Sichuan and Hunan cuisine restaurant as an example, since the concentration of non-methane total hydrocarbons and oil fume emissions in Sichuan and Hunan cuisine are relatively high, in order to achieve the purification effect, it is necessary to select a higher purification component layout. At the same time, in order to further reduce resistance, a suction, exhaust and purification device is used to achieve the minimum space size and the lowest power consumption level.

[0060] Therefore, the selection of the purification component of the present invention specifically includes the following steps:

[0061] S1) Determine the basic purification parameters:

[0062] a) Cooking method Pi, i is a natural number, indicating the number corresponding to the classification of the cooking method, and Pi corresponding to different i indicates different cooking methods, and the difference between the cooking methods is mainly based on the oil fume emission concentration and non-methane total hydrocarbon concentration generated by cooking. For example, in this embodiment, i=1-4, among which Sichuan and Hunan cuisine is P1, Cantonese cuisine is P2, rice and noodles are P3, hot pot restaurants are P4, etc. Other cooking methods are classified into the above four types of cooking methods with the same or similar oil fume concentration and non-methane total hydrocarbon concentration;

[0063] b) Purification efficiency configuration Lj: j is a natural number, indicating the number corresponding to the classification of the expected purification efficiency. Different j corresponding to Lj indicates different purification efficiency configurations. For example, in this embodiment, j=1-3, high configuration L1, purification efficiency is 95%, medium configuration L2, purification efficiency is 85%, low configuration L3, purification efficiency is 80%;

[0064] c) Scale Yw: w is a natural number, indicating the number corresponding to the scale (number of stoves) of the commercial kitchen where the smoke exhaust system is located. Different w corresponds to different scales. For example, in this embodiment, w=1-3. If Q0 / 2000>6, it is Y3, corresponding to a large catering unit; if 4<Q0 / 2000≤6, it is Y2, corresponding to a medium-sized catering unit; if Q0 / 2000≤4, it is Y1, corresponding to a small catering unit;

[0065] S2) obtain the recommended purification component layout Hm=F(Pi, Lj, Yw), where m is a natural number, indicating the number corresponding to the classification of the purification component layout, and H is the result determined by P, L and Y. In this embodiment, m=1-3, that is, there are three purification component layouts available for selection. In this embodiment, the layout includes the selection of the type of purification module, the selection of the number of purification modules and the arrangement position of the purification modules, etc. The type of purification module selection includes the selection of filtering method, material, thickness, etc.; the combination of different basic purification parameters can obtain the preferred purification component layout scheme, which can be determined in advance through experiments or based on empirical values, and the optional schemes of the purification component layout are stored in a data table, and the parameters can be input when selecting to select and determine.

[0066] The above-obtained purification assembly layout scheme Hm is combined with the length L of the exhaust pipe 2 and the number S of the elbows of the exhaust pipe 2 to obtain the wind resistance P = (L*f1+S*f2+H) / Q 2 , where f1 is the pressure difference per unit distance of the exhaust pipe, f2 is the pressure difference of a single elbow, and H is the pressure difference under the current layout of the purification components (from the most upstream to the most downstream where the purification components are located). The above three pressure differences can be obtained in advance through experiments. The unit of P is kilo-millimeter, the unit of pressure difference is millimeter of water column, and the unit of Q is m 3 / min (can be expressed by m 3 / h converted).

[0067] Through the above-mentioned recommended exhaust volume Q and wind resistance P, the final selection of fan system 3 is obtained. The performance parameters of the fan system 3 need to meet (except for the redundancy coefficient, which is the existing relationship), and the units are all national standards: The air volume Q of the fan system 3 风 =Q*n2; Wind pressure P of fan system 3 风 =P*n3; Power of fan system 3 W = Q 风 *P 风 *n1 / (3600*η1*η2*1000), η1 is the fan efficiency, preferably 0.719-0.8; η2 is the mechanical transmission efficiency, such as 0.95 for V-belt transmission and 0.98 for coupling transmission; the speed of the fan system 3 N=F(Q, P), and the function F(Q, P) can be obtained according to experiments. Among them, n1, n2 and n3 are redundancy coefficients, all greater than 1 and less than 1.5. The performance of the fan system is designed to have a certain redundancy to avoid being affected by environmental factors and other factors in actual application. In this embodiment, n1 is preferably 1.3, n2 is preferably 1.1, and n3 is preferably 1.1.

[0068] Based on the performance parameter requirements of the fan system 3, a fan system model that meets the requirements can be selected from the fan product library.

[0069] Thus, the fan system 3 and purification components of the smoke exhaust system are determined.

[0070] In addition, in order to better improve the effect of oil fume absorption, in the present invention, the final selection of the smoke exhaust system also includes the selection of the air supply system. According to the recommended exhaust volume Q, combined with the actual air supply ventilation conditions, select the implementation method of mechanical air supply and / or natural air supply. Mechanical air supply refers to the commonly used in this field, such as air supply through an air supply fan. If it is natural air supply, it is necessary to determine the preferred area of ​​windows and open doors: 1) Window area: A4 = Q 补风 / d1; 2) Open door area: A5 = Q 补风 / d2; if it is mechanical air supply, then Q 补风 =d3*Q. d1, d2 and d3 are all constant coefficients not greater than 1, such as d1 can be selected as 0.28, d2 can be selected as 0.38, and d3 can be selected as 0.8, so that the final Q 补风 The ratio to Q is between 0.8 and 1.

[0071] The air supply form is determined in this way, and the final smoke exhaust system is selected by combining the fan system 3 and the purification components.

Claims

1. A method for selecting a commercial smoke exhaust system, the commercial smoke exhaust system comprising an exhaust hood (1) arranged above a stove (100), a purification component and a fan system (3) being arranged in the exhaust hood (1), a stove head (101) and a pot (200) placed on the stove head (101) being arranged on the top of the stove (100), and a cooking module (300) being arranged in the stove (100) for generating oil smoke or steam and being sucked into the exhaust hood (1); characterized in that: The selection method includes the selection of purification components and fan system (3); The selection of the purification component includes the following steps: S1) Determine the basic purification parameters: A) cooking method Pi, i is the number corresponding to the classification of the cooking method; B) Purification efficiency configuration Lj: j is the number corresponding to the classification of the expected purification efficiency; C) Scale Yw: w represents the number corresponding to the scale of the commercial kitchen where the exhaust system is located; S2) obtaining a recommended purification component layout Hm=F(Pi, Lj, Yw), where m represents the number corresponding to the classification of the purification component layout, and the relationship between Hm and Pi, Lj and Yw is determined and stored in advance through experiments or empirical values; The selection of the fan system (3) comprises the following steps: s1) Determine the basic parameters of air volume: a) the number of stoves (101), denoted as Z1; b) the total horizontal projection area of ​​the exhaust hood (1) on the stove (100), denoted as A1; c) the number of cooking modules (300), denoted as Z2; d) the horizontal projection area of ​​the cooking module (300), denoted as A2; e) the diameter of the pot (200), denoted as G; s2) Calculate the total projected area A0 based on Z1, A1, Z2 and A2; s3) obtaining a recommended exhaust volume Q=Q0*A0, wherein Q0 is a reference exhaust volume of a single stove head (101); s4) calculating the performance parameters of the fan system (3) according to the wind resistance P and exhaust volume Q of the smoke exhaust system after the layout of the purification components is determined, and determining the type of the fan system (3).

2. The method for selecting a commercial smoke exhaust system according to claim 1, characterized in that: In step S1) of selecting the purification component, cooking methods are distinguished by the concentration of oil fume emissions and the concentration of non-methane total hydrocarbons.

3. The method for selecting a commercial smoke exhaust system according to claim 1, characterized in that: In step S1) of selecting the purification component, the size is determined by the number of burners (101).

4. The method for selecting a commercial smoke exhaust system according to claim 1, characterized in that: In the step S2) of selecting the purification component, the layout of the purification component includes the selection of the type of purification module, the selection of the number of purification modules and the selection of the position of the purification module.

5. The method for selecting a commercial smoke exhaust system according to claim 1, characterized in that: In step s2) of selecting the fan system (3), first determine whether G is less than G0. If so, proceed to step s2.1). If not, proceed to step s2.2). G0 is a preset threshold value of the size of the cookware (200): s2.1) Calculate the total projected area A0, A0=MAX(A1,Z1*A 标1 )+MAX(A2,Z2* A 标2 ); s2.2) Calculate the total projected area A0, A0 = MAX(Z1* A 标3 )+MAX(A2,Z2* A 标2 ); Among them, A 标1 and A 标3 The standard value of the exhaust hood stove projection corresponding to a single reference stove head, and meets A 标3 >A 标1 , A 标2 This is the projection standard value of a single cooking module (300).

6. The method for selecting a commercial smoke exhaust system according to claim 1, characterized in that: The commercial smoke exhaust system also includes a smoke exhaust pipe (2), wind resistance P = (L*f1+S*f2+H) / Q 2 , wherein f1 is the pressure difference per unit distance of the exhaust pipe (2), f2 is the pressure difference of the elbow of a single exhaust pipe (2), H is the pressure difference under the current purification component layout, L is the length of the exhaust pipe (2), and S is the number of elbows of the exhaust pipe (2).

7. The method for selecting a commercial smoke exhaust system according to claim 1, characterized in that: The performance parameters of the fan system (3) include air volume Q 风 , wind pressure P 风 , power W and speed N.

8. The method for selecting a commercial smoke exhaust system according to claim 7, characterized in that: Q 风 =Q*n2;P 风 =P* n3; W=Q 风 *P 风 *n1 / (3600*η1*η2*1000), N=F(Q, P), the function F(Q, P) is obtained through experiments, n1, n2 and n3 are redundancy coefficients, all greater than 1 and less than 1.

5.

9. The method for selecting a commercial smoke exhaust system according to claim 1, characterized in that: The selection method also includes the selection of an air supply system, where the air supply is achieved by mechanical air supply and / or natural air supply, so that the final air supply volume Q 补风 The ratio to Q is between 0.8 and 1.

Images