A centralized smoke exhaust and make-up air system for buildings

Abstract

The present invention relates to a centralized smoke exhaust and air supply system for buildings, which is characterized in that it includes an indoor range hood, a common smoke exhaust duct, a common air supply duct, an air supply system, an air supply valve, and an indoor control box. The indoor control box and the air supply system are configured such that when the indoor range hood in a certain household kitchen is turned on, the indoor control box obtains the exhaust air volume of the indoor range hood and sends it to the air supply system in real time. The air supply system controls the output air supply volume according to the sum of the exhaust air volumes of all the turned-on indoor range hoods, and at the same time controls the opening angle of the air supply valve so that the air intake volume entering the corresponding household kitchen is the same as the exhaust air volume of the indoor range hood in the corresponding household kitchen; the exhaust air volume Q of the indoor range hood = sqrt(△P / K), where sqrt is the square root function. Compared with the prior art, the present invention can achieve that the indoor temperature is not disturbed, and the models and brands of the installed indoor range hoods can be unrestricted.

Description

Technical Field

[0001] The present invention relates to a centralized smoke exhaust and air supply system for buildings. Background Art

[0002] Currently, there are two scenarios for the demand of kitchen air supply. One is in cold northern regions where doors and windows are closed in winter. When the range hood in the kitchen is operating, the interior of the kitchen will present a negative pressure, resulting in poor smoking effect of the range hood. Therefore, air supply is required. The other is for a constant-temperature indoor environment. When the range hood is operating, the air flow in the room and living room is sucked into the range hood, and the indoor temperature balance will be quickly disrupted. Therefore, active air supply is also required near the range hood.

[0003] For residential buildings, especially high-rise residential buildings, the current common solution is split air supply, that is, an air supply valve is installed on the kitchen ceiling of each residential user. One end of the air supply valve is connected to the outside, and the other end is connected to the interior of the kitchen. When the range hood is turned on, the air supply valve is opened, and when the range hood is turned off, the air supply valve is closed, so as to balance the pressure inside the kitchen. There are also some patents that mention the technical solution of centralized air supply. For example, the Chinese utility model patent with the publication number CN 215001761U proposes an air supply system for the kitchen, which includes an air supply power component, an air duct, a pressure detection component, and an air supply valve component. One end of the air supply power component is connected to the outside, and the other end is connected to one end of the air supply valve component through the air duct. The other end of the air supply valve component is connected to the kitchen, and the pressure detection component is connected to the air supply valve component. When the above air supply system is in use, the air supply valve component obtains the working state of the range hood. When the range hood is in the working state, the pressure detection component obtains the pressure difference between the inside and outside of the kitchen, and then the air supply valve component controls the working states of the air supply power component and itself according to the pressure difference.

[0004] Split air supply can solve the demand of the first scenario, but for the second scenario, the split air supply valve cannot control the constant-temperature air in the room from being sucked into the range hood. For example, when the range hood is turned on and the kitchen door is also open, the air flow will be sucked into the kitchen from the living room or the room, rather than entering from the position of the air supply valve. In addition, the split air supply solution requires drilling holes in the wall of the user's residence and installing a rain shield at the corresponding outdoor air inlet, which will have a certain impact on the aesthetics of the facade and the air supply volume is limited. Centralized air supply is through the linkage method of the range hood. When the range hood is turned on, the outdoor air supply main unit supplies air to the room, which can achieve sufficient air supply effect to the kitchen, but it is quite difficult to accurately control the air supply volume. Summary of the Invention

[0005] The technical problem to be solved by the present invention is a centralized smoke exhaust and air supply system for buildings that can accurately control the air supply volume entering the user's kitchen to ensure that the indoor temperature is not affected.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows: A building centralized smoke exhaust and air supply system, characterized in that it includes an indoor range hood disposed inside the kitchens of each household in the building, a public smoke exhaust duct disposed inside the building, a public air supply duct disposed inside the building, and an air supply system. Among them, the public smoke exhaust duct and the public air supply duct are independently arranged. The air outlet of the air supply system is communicated with the inlet of the public air supply duct. An air supply opening is provided inside the kitchens of each household in the building, and the air supply opening is directly communicated with the public air supply duct or communicated with the public air supply duct through an indoor air supply duct. A compensating air valve with an adjustable opening angle is provided at the air supply opening or at the inlet or outlet or inside of the indoor air supply duct; the air outlet of the indoor range hood inside the kitchens of each household in the building is communicated with the public smoke exhaust duct through an indoor smoke exhaust pipe; in addition, an indoor control box is also provided inside the kitchens of each household in the building. The indoor range hoods and compensating air valves inside the kitchens of different households are respectively communicatively connected with the indoor control box inside the corresponding household kitchens, and all the indoor control boxes inside the household kitchens are communicatively connected with the air supply system; the indoor control box and the air supply system are configured as follows: when the indoor range hood inside a certain household kitchen is turned on, the indoor control box inside the corresponding household kitchen obtains the exhaust air volume of the indoor range hood and sends it to the air supply system in real time. The air supply system controls the output air supply volume according to the sum of the exhaust air volumes of all the turned-on indoor range hoods, and at the same time sends a control instruction to the indoor control box inside the corresponding household kitchen. The indoor control box inside the corresponding household kitchen controls the opening angle of the corresponding compensating air valve so that the air intake volume entering the corresponding household kitchen is the same as the exhaust air volume of the indoor range hood inside the corresponding household kitchen; among them, the indoor control boxes inside the kitchens of different households obtain the exhaust air volumes of the correspondingly connected indoor range hoods in the following manner:

[0007] Connect a resistance pipe at the inlet or outlet of the indoor smoke exhaust pipe. The resistance pipe has a structure in which the diameter in the middle is reduced and gradually increases towards both ends. Install a pressure sensor at each of the inlet and outlet of the resistance pipe, and connect the two pressure sensors to the indoor control box respectively. The indoor control box obtains the pressure difference △P before and after the resistance pipe through the data collected by the two pressure sensors, and then calculates the exhaust air volume Q of the indoor range hood according to the set resistance coefficient K, Q = sqrt(△P / K), where sqrt is the square root function.

[0008] Preferably, the diameters inside both ends of the resistance pipe are the same as the diameter of the indoor smoke exhaust pipe, and the diameter at the smallest diameter in the middle of the resistance pipe is smaller than the diameters inside both ends and not less than 155 mm.

[0009] As an improvement, the air supply openings inside the households on each floor are communicated with the public air supply duct through indoor air supply ducts; the public air supply duct has a length and width of L respectively x, L y A rectangular pipeline of y ; a pressure sensor is provided at the inlet of the common air supply duct, and the pressure sensor is communicatively connected to the air supply system; when the indoor range hood in a certain household kitchen is turned on, the indoor control box inside the corresponding household kitchen obtains the exhaust air volume of the indoor range hood and sends it to the air supply system in real time. At the same time, the indoor control box inside the corresponding household kitchen controls the air supply valve in the household from the closed state to the open state, and adjusts the opening angle of the air supply valve in the household to 90°. The air supply system sets the initial pressure value at the inlet of the common air supply duct according to the startup rate of the indoor range hood, assigns the initial pressure value to P0, and then executes the following control steps:

[0010] Step 1: Select N sampling points from the bottom to the top inside the common air supply duct, and record the pressure values at the cross-sections where these N sampling points are located as P1, P2, …… P n-1 , P n , …… P N ; The first sampling point and the second sampling point are respectively located above and below the air supply opening of the first-floor household or the inlet of the indoor air supply duct, ……, the n-1th sampling point and the nth sampling point are respectively located above and below the air supply opening of the nth-floor household or the inlet of the indoor air supply duct, ……, the N-1th sampling point and the Nth sampling point are respectively located above and below the air supply opening of the Nth-floor household or the inlet of the indoor air supply duct, where N is the total number of floors of the building; then calculate the pressure values at the cross-sections where each sampling point in the common air supply duct is located through the following formula:

[0011] P n-1 = P n + △P n1 + △P yn

[0012] In the above formula, P n-1 represents the pressure value at the cross-section where the (n-1)th sampling point is located, P n-1 represents the pressure value at the cross-section where the nth sampling point is located, △P n1 represents the pressure value consumed when the fluid flows from the sampling point n-1 to the sampling point n, and the calculation formula of △P n1 is:

[0013] △P n1 = f(V n / V n内 ) · V n内 · V n内 / (L x · L y )

[0014] In the above formula, V n , V n内are the air flow velocity at sampling point n in the common make-up air duct and the gas flow velocity in the indoor make-up air duct on the nth floor, respectively. The function f(V n / V n内 ) is a cubic polynomial function of the variable V n / V n内 ; L x and L y are the length and width of the inner cross-section of the common make-up air duct, respectively;

[0015] f(V n / V n内 ) = K1 + A1·(V n / V n内 ) + B1·(V n / V n内 ) 2 + C1·(V n / V n内 ) 3 , where K1, A1, B1, and C1 are preset constants;

[0016] △P yn is the frictional resistance loss in the common make-up air duct:

[0017] △P yn = λ1·ρ·Q n 2 ·h*(L x + L y ) / [4·(L x ·L y ) 3

[0018] In the above formula, λ1 is the frictional resistance coefficient of the common make-up air duct, which is a preset value, ρ is the air density, Q n is the exhaust air volume of the indoor range hood in the kitchen on the nth floor, h is the floor height, L x and L y are the length and width of the inner cross-section of the common make-up air duct, respectively;

[0019] Through iterative calculation, using P0 = P1 + △P 11 + △P y1 , calculate P1, P2... P N respectively;

[0020] Step 2: Calculate the internal pressure value in the indoor make-up air duct of each floor household's kitchen through the following formula:

[0021] P n内 = P n-1 - △P n2

[0022] In the above formula, n-1 ​The pressure value at the cross-section where the (n - 1)-th sampling point is located, P n内 The pressure value in the indoor make-up air duct of the n-th floor, △P n2 Indicates the total pressure difference between the cross-section where the (n - 1)-th sampling point in the common make-up air duct is located and the indoor make-up air duct of the n-th floor:

[0023] △P n2 = F(V n / V n内 )·V n内 ·V n内

[0024] F(V n / V n内 ) is a cubic polynomial function of the variable V n / V n内 :

[0025] F(V n / V n内 ) = K2 + A2·(V n / V n内 ) + B2·(V n / V n内 ) 2 + C2·(V n / V n内 ) 3 , where K2, A2, B2, and C2 are preset constants;

[0026] Step 3: Calculate the static pressure value in the kitchen of each floor household through the following formula:

[0027] P n厨房 = P n内 - P n动 - △P F - △P g

[0028] P n厨房 Indicates the static pressure value in the kitchen of the n-th floor household, P n动 = 0.5·ρ·V n内 ·V n内 , ρ is the air density, △P F Indicates the pressure loss consumed by the fluid passing through the make-up air valve, △P F = k1e k2 · (90-θ) ·(ρ·V n内 2 / 2), k1, k2 are constants, θ is the opening angle of the make-up air valve on the n-th floor, and the initial value of θ is equal to 90°; △P g Indicates the resistance loss that the air flow needs to overcome from the make-up air valve outlet to the kitchen, △P g = k·Qn 2 , where k is the resistance coefficient of the indoor air supply duct and the air supply opening, and is a preset constant; Q n is the exhaust air volume of the indoor range hood in the kitchen on the nth floor;

[0029] Step 4. Determine whether |P n厨房 | is less than or equal to 3 Pa. If P n厨房 is less than -3 Pa, determine whether the opening angle θ of the air supply valve where the nth floor is located is less than 90°. If not, directly return to Step 1. If so, increase the opening angle of the air supply valve where the nth floor is located by 0.2°, and then return to Step 1; if P n厨房 is greater than 3 Pa, decrease the opening angle of the air supply valve where the nth floor is located by 0.2°, and then return to Step 1; if |P n厨房 | is less than or equal to 3 Pa, enter Step 5;

[0030] Step 5. Determine whether the number of air supply valves with a final opening angle equal to 90° among all household floors is greater than 1. If not, decrease the value of P0 by 2 units, and then return to Step 1; if so, the calculation ends. The air supply system sends the final calculated opening angles of the air supply valves in each floor of the household to the indoor control box inside the kitchen on the nth floor; at the same time, adjust the air supply volume that the air supply system needs to deliver according to the finally calculated P0, and use the pressure data fed back by the pressure sensor at the inlet of the common air supply duct to make the pressure value at the inlet of the common air supply duct reach the finally calculated P0 value.

[0031] The air supply opening can be set on the ceiling of each household kitchen, or on the wall or the cabinet.

[0032] The air supply system is preferably set in the basement of the building, which can make good use of the characteristics of the basement being warm in winter and cool in summer, and at the same time can well solve the problem that outdoor rainwater is easily sucked into the kitchen for supplementation.

[0033] The air supply system includes an air supply fan, an air supply electric control system, an air supply box and a purification filter. The air supply fan is arranged in the air supply box. The air supply box is provided with an air inlet and an air outlet. The purification filter is arranged at the air inlet. The air supply electric control system is electrically connected to the air supply fan and can control the air volume of the air supply fan. The air outlet of the air supply box is communicated with the inlet of the common air supply duct.

[0034] Compared with the prior art, the advantages of the present invention are as follows: In terms of the overall system architecture, by adding a make-up air system and adopting the idea of balancing make-up air, the make-up air volume of the make-up air system is determined according to the exhaust air volume of the indoor range hood, and the two are equal, so that the indoor temperature can be undisturbed. In addition, for the method of obtaining the exhaust air volume of the indoor range hood, by connecting a resistance pipe at the inlet or outlet of the indoor exhaust pipe to measure the pressure difference, and calculating the exhaust air volume according to the resistance coefficient and the pressure difference, the model and brand of the installed indoor range hood are not restricted, and the application range is wider. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic structural diagram of the building centralized smoke exhaust and make-up air system in the embodiment of the present invention.

[0036] Figure 2 It is a schematic structural diagram of the indoor exhaust pipe and the resistance pipe on the nth floor in the embodiment of the present invention.

[0037] Figure 3 It is a schematic structural diagram of the settings of the upper and lower two sampling points in the corresponding public make-up air duct on the nth floor and the indoor make-up air duct on the nth floor in the embodiment of the present invention.

[0038] Figure 4 It is a control flow chart of the building centralized smoke exhaust and make-up air system in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The present invention will be further described in detail below with reference to the embodiments of the drawings.

[0040] As Figure 1 shown in the building centralized smoke exhaust and make-up air system, it includes indoor range hoods 11... 1N installed in the kitchens of each household in the building, where N is the total number of floors in the building, a public smoke exhaust duct 2 installed in the building, a public make-up air duct 3 installed in the building, and a make-up air system 4. The make-up air system 4 is installed in the basement 10 of the building. The make-up air system 4 includes a make-up air fan 41, a make-up air electric control system 42, a make-up air box 43, and a purification filter screen 44. The make-up air fan 41 is installed in the make-up air box 43. The make-up air box 43 is provided with an air inlet and an air outlet. The purification filter screen 44 is installed at the air inlet. The make-up air electric control system 42 is electrically connected to the make-up air fan 41 and can control the air volume of the make-up air fan. The air outlet of the make-up air box 43 is communicated with the inlet of the public make-up air duct 3. The public smoke exhaust duct 2 and the public make-up air duct 3 are independently arranged. The public make-up air duct has a length and width of L x 、L yA rectangular pipeline; the air outlets of the indoor range hoods 11, ……, 1N inside the kitchens of each household in the building are connected to the common exhaust duct 2 through the indoor exhaust pipes 51, ……, 5N; air supply inlets 71, ……, 7N are provided inside the kitchens of each household in the building, and the air supply inlets are arranged on the suspended ceilings of the kitchens of each household. The air supply inlets are connected to the common air supply duct 3 through the indoor air supply pipes 91, ……, 9N; air supply valves 81, ……, 8N with adjustable opening angles are provided at the inlets of the indoor air supply pipes 91, ……, 9N; at the same time, indoor control boxes 61, ……, 6N are also provided inside the kitchens of each household in the building. The indoor range hoods 11, ……, 1N inside the kitchens of different households are respectively communicatively connected to the indoor control boxes 61, ……, 6N inside the corresponding household kitchens. The air supply electric valves 81, ……, 8N inside the rooms of each floor user are all communicatively connected to the indoor control boxes 61, ……, 6N on the corresponding floors. The indoor control boxes 61, ……, 6N inside the kitchens of all households are all communicatively connected to the air supply electric control system 42. The indoor control boxes 61, ……, 6N and the air supply electric control system 42 are configured such that when the indoor range hood inside a certain household kitchen is turned on, the indoor control box inside the corresponding household kitchen obtains the exhaust air volume of the indoor range hood and sends it to the air supply electric control system 42 in real time. The air supply electric control system 42 controls the air supply volume output by the air supply fan 41 according to the sum of the exhaust air volumes of all the turned-on indoor range hoods, and at the same time, also sends a control instruction to the indoor control boxes 61, ……, 6N inside the corresponding household kitchens. The indoor control boxes 61, ……, 6N inside the corresponding household kitchens control the opening angles of the corresponding air supply valves 81, ……, 8N so that the air supply volume entering the corresponding household kitchen is the same as the exhaust air volume of the indoor range hood inside the corresponding household kitchen.

[0041] Among them, the indoor control boxes inside the kitchens of different households obtain the exhaust air volumes of the corresponding connected indoor range hoods in the following way:

[0042] At the outlets of the indoor exhaust pipes 51, ……, 5N on each floor, a resistance pipe 101, ……, 10N is respectively connected. The resistance pipe has a structure where the diameter in the middle is reduced and gradually increases towards both ends. A pressure sensor is installed at each of the inlet and outlet of the resistance pipe, and the two pressure sensors are respectively connected to the indoor control box. The indoor control box obtains the pressure difference △P before and after the resistance pipe through the data collected by the two pressure sensors, and then calculates the exhaust air volume Q of the indoor range hood according to the set resistance coefficient K, Q = sqrt(△P / K), where sqrt is the square root function. Taking the indoor exhaust pipe 5n on the nth floor as an example, refer to Figure 2As shown, a resistance pipe 10n is connected to the outlet of the indoor smoke exhaust pipe 5n. A pressure sensor 101n and a pressure sensor 102n are installed at the inlet and outlet of the resistance pipe 10n respectively. The two pressure sensors 101n and 102n are respectively connected to the indoor control box 6n on the corresponding floor. The indoor control box obtains the pressure difference △P before and after the resistance pipe through the data collected by the two pressure sensors, and then calculates the exhaust air volume Q of the range hood in this layer according to Q = sqrt(△P / K).

[0043] In addition, a pressure sensor 31 is arranged at the inlet of the public air supply pipe. The pressure sensor 31 is communicatively connected to the air supply electric control system 42 of the air supply system; when the range hood in the kitchen of a certain household is turned on, the indoor control box in the kitchen of the corresponding household obtains the exhaust air volume of the range hood and sends it to the air supply system in real time. At the same time, the indoor control box in the kitchen of the corresponding household controls the air supply valve in this household from the closed state to the open state, and adjusts the opening angle of the air supply valve in this household to 90°. The air supply system sets the initial pressure value at the inlet of the public air supply pipe according to the startup rate of the range hood, and assigns this initial pressure value to P0, and then executes the following control steps, see Figure 4 as follows:

[0044] Step 1: Select N sampling points from bottom to top inside the public air supply pipe, and record the pressure values at the cross-sections where these N sampling points are located as P1, P2, …… P n-1 , P n , …… P N ; The first sampling point and the second sampling point are respectively located above and below the air supply opening of the first-floor household or the inlet of the indoor air supply pipe, ……, the n-1th sampling point and the nth sampling point are respectively located above and below the air supply opening of the nth-floor household or the inlet of the indoor air supply pipe, ……, the N-1th sampling point and the Nth sampling point are respectively located above and below the air supply opening of the Nth-floor household or the inlet of the indoor air supply pipe, and N is the total number of floors of the building; then calculate the pressure values at the cross-sections where each sampling point in the public air supply pipe is located through the following formula:

[0045] P n-1 = P n + △P n1 + △P yn

[0046] In the above formula, P n-1 represents the pressure value at the cross-section where the n-1th sampling point is located, and P n-1 represents the pressure value at the cross-section where the nth sampling point is located, see Figure 3 as shown, △P n1 represents the pressure value consumed when the fluid flows from the sampling point n-1 to the sampling point n, and △P n1The calculation formula is as follows:

[0047] △P n1 = f(V n / V n内 )·V n内 ·V n内 / (L x ·L y )

[0048] In the above formula, V n and V n内 are respectively the air flow velocity at the sampling point n in the common make-up air duct and the gas flow velocity in the indoor make-up air duct on the nth floor. The function f(V n / V n内 ) is a cubic polynomial function of the variable V n / V n内 ; L x and L y are respectively the length and width of the inner cross-section of the common make-up air duct;

[0049] f(V n / V n内 ) = K1 + A1·(V n / V n内 ) + B1·(V n / V n内 ) 2 + C1·(V n / V n内 ) 3 , where K1, A1, B1, and C1 are preset constants;

[0050] △P yn is the frictional resistance loss in the common make-up air duct:

[0051] △P yn = λ1·ρ·Q n 2 ·h*(L x + L y ) / [4·(L x ·L y ) 3

[0052] In the above formula, λ1 is the frictional resistance coefficient of the common make-up air duct, which is a preset value, ρ is the air density, Q n is the exhaust air volume of the indoor range hood in the kitchen on the nth floor, h is the storey height, and L x and L y are respectively the length and width of the inner cross-section of the common make-up air duct;

[0053] Through iterative calculation, using P0 = P1 + △P 11 + △P​y1 , calculate P1, P2... P N ;

[0054] Step 2: Calculate the internal pressure value in the indoor make-up air duct in the kitchens of households on each floor through the following formula:

[0055] P n内 = P n-1 - △P n2

[0056] In the above formula, n-1 represents the pressure value at the cross-section where the (n - 1)th sampling point is located, P n内 is the pressure value inside the indoor make-up air duct on the nth floor, and △P n2 represents the total pressure difference between the cross-section where the (n - 1)th sampling point is located in the common make-up air duct and the indoor make-up air duct on the nth floor:

[0057] △P n2 = F(V n / V n内 ) · V n内 · V n内

[0058] F(V n / V n内 ) is a cubic polynomial function of the variable V n / V n内 :

[0059] F(V n / V n内 ) = K2 + A2 · (V n / V n内 ) + B2 · (V n / V n内 ) 2 + C2 · (V n / V n内 ) 3 , where K2, A2, B2, and C2 are preset constants;

[0060] Step 3: Calculate the static pressure value in the kitchens of households on each floor through the following formula:

[0061] P n厨房 = P n内 - P n动 - △P F - △P g

[0062] P n厨房 represents the static pressure value in the kitchen of the household on the nth floor, P n动 = 0.5 · ρ · V n内 · V n内 , ρ is the air density, and △PF Indicates the pressure loss consumed by the air make-up valve when the fluid passes through it, ΔP F = k1e k2 · (90-θ) ·(ρ·V n内 2 / 2), where k1 and k2 are constants, θ is the opening angle of the nth layer air make-up valve, and the initial value of θ is equal to 90°; ΔP g Indicates the resistance loss that the air flow needs to overcome from the outlet of the air make-up valve to the kitchen interior, ΔP g = k·Q n 2 , where k is the resistance coefficient of the indoor air make-up duct and the air make-up opening, which is a preset constant; Q n is the exhaust air volume of the indoor range hood in the nth layer kitchen;

[0063] Step 4. Determine whether |P n厨房 | is less than or equal to 3 Pa. If P n厨房 is less than -3 Pa, determine whether the opening angle θ of the air make-up valve where the nth layer is located is less than 90°. If not, directly return to Step 1. If so, increase the opening angle of the air make-up valve where the nth layer is located by 0.2°, and then return to Step 1; if P n厨房 is greater than 3 Pa, decrease the opening angle of the air make-up valve where the nth layer is located by 0.2°, and then return to Step 1; if |P n厨房 | is less than or equal to 3 Pa, proceed to Step 5;

[0064] Step 5. Determine whether the number of air make-up valves with the final opening angle equal to 90° among all household floors is greater than 1. If not, decrease the value of P0 by 2 units, and then return to Step 1; if so, the calculation ends. The air make-up system sends the opening angles of the air make-up valves for each floor household calculated finally to the indoor control box inside the nth layer kitchen. After receiving the opening angles of the air make-up valves sent by the air make-up system, the nth layer indoor control box controls the corresponding floor air make-up valve to make the opening angle of the corresponding floor air make-up valve the finally calculated θ; at the same time, adjust the air make-up volume that the air make-up system needs to deliver according to the finally calculated P0, and use the pressure data fed back by the pressure sensor at the inlet of the common air make-up duct to make the pressure value at the inlet of the common air make-up duct the finally calculated P0 value.

[0065] Taking a 30-story building project as an example, with the size of the common air supply duct being 350*300mm and the floor height being 3m, suppose there are currently 9 households cooking on floors 1, 4, 6, 11, 15, 19, 23, 26, and 30. When the indoor control box detects the actual exhaust air volumes on the powered-on floors as 420 m³ / h on the 1st floor, 435 m³ / h on the 4th floor, 450 m³ / h on the 6th floor, 480 m³ / h on the 11th floor, 495 m³ / h on the 15th floor, 525 m³ / h on the 19th floor, 570 m³ / h on the 23rd floor, 585 m³ / h on the 26th floor, and 615 m³ / h on the 30th floor; after the air supply system obtains the actual exhaust air volumes on these floors, it can calculate the corresponding air supply valve angle θ and the static pressure value P0 required at the inlet of the common air supply duct. The results are shown in the following table. It can be seen that for the lower floors, due to the small exhaust air volume and being close to the air supply system, the angle of the electric valve is relatively small at this time, and the angle of the electric valve for the higher floors is relatively large. The static pressure value inside the kitchen is between -3 Pa and +3 Pa, and the static pressure value P0 that needs to be provided at the inlet of the common air supply duct is 324 Pa.

[0066]

[0067]

Claims

1. A centralized smoke exhaust and air supply system for buildings, characterized in that: It includes an indoor range hood installed inside the kitchens of each household in a building, a public exhaust duct installed inside the building, a public air supply duct installed inside the building, and an air supply system. The public exhaust duct and the public air supply duct are independently installed. The air outlet of the air supply system is connected to the inlet of the public air supply duct. Each household kitchen in the building is provided with an air supply opening, which is directly connected to the public air supply duct or connected to the public air supply duct through an indoor air supply duct. A wind supply valve with an adjustable opening angle is provided at the air supply opening or at the inlet or outlet or inside of the indoor air supply duct; the air outlet of the indoor range hood in each household kitchen in the building is connected to the public exhaust duct through an indoor exhaust pipe; in addition, an indoor control box is also installed inside each household kitchen in the building. The indoor range hoods and the wind supply valves in different household kitchens are communicatively connected to the indoor control box in the corresponding household kitchen, and all the indoor control boxes in the household kitchens are communicatively connected to the air supply system; the indoor control box and the air supply system are configured such that when the indoor range hood in a certain household kitchen is turned on, the indoor control box in the corresponding household kitchen obtains the exhaust air volume of the indoor range hood and sends it to the air supply system in real time. The air supply system controls the output air supply volume according to the sum of the exhaust air volumes of all the turned-on indoor range hoods, and at the same time sends a control instruction to the indoor control box in the corresponding household kitchen. The indoor control box in the corresponding household kitchen controls the opening angle of the corresponding wind supply valve so that the air intake volume entering the corresponding household kitchen is the same as the exhaust air volume of the indoor range hood in the corresponding household kitchen; wherein the indoor control boxes in different household kitchens obtain the exhaust air volumes of the correspondingly connected indoor range hoods in the following manner: Connect a resistance pipe at the inlet or outlet of the indoor exhaust pipe. The resistance pipe has a structure in which the diameter in the middle is reduced and gradually increases towards both ends. Install a pressure sensor at each of the inlet and outlet of the resistance pipe, and connect the two pressure sensors to the indoor control box respectively. The indoor control box obtains the pressure difference △P before and after the resistance pipe through the data collected by the two pressure sensors, and then calculates the exhaust air volume Q of the indoor range hood according to the set resistance coefficient K. Q = sqrt(△P / K), where sqrt is the square root function.

2. The centralized smoke exhaust and air supply system for buildings according to claim 1, wherein: The diameters of the two ends inside the resistance pipe are the same as the diameter of the indoor exhaust pipe, and the diameter at the smallest diameter in the middle of the resistance pipe is smaller than the diameters of the two ends inside, and is not less than 155 mm.

3. The centralized smoke exhaust and air supply system for buildings according to claim 1, characterized in that: The air supply inlets inside the households on each floor are connected to the public air supply duct through indoor air supply pipes; the public air supply duct is a rectangular parallelepiped duct with a length and width of L x and L y respectively; a pressure sensor is arranged at the inlet of the public air supply duct, and the pressure sensor is communicatively connected to the air supply system; when the indoor range hood in the kitchen of a certain household is turned on, the indoor control box inside the corresponding household kitchen obtains the exhaust air volume of the indoor range hood and sends it to the air supply system in real time. At the same time, the indoor control box inside the corresponding household kitchen controls the air supply valve inside the household from the closed state to the open state, and adjusts the opening angle of the air supply valve inside the household to 90°. The air supply system sets the initial pressure value at the inlet of the public air supply duct according to the startup rate of the indoor range hood, assigns the initial pressure value to P0, and then executes the following control steps: Step 1: Select N sampling points from the inside of the common air supply duct from bottom to top, and record the pressure values at the cross-sections where these N sampling points are located as P1, P2, …… P n-1 , P n , …… P N ; The first sampling point and the second sampling point are respectively located above and below the air supply opening of the first-floor household or the inlet of the indoor air supply duct, ……, the (n - 1)th sampling point and the nth sampling point are respectively located above and below the air supply opening of the nth-floor household or the inlet of the indoor air supply duct, ……, the (N - 1)th sampling point and the Nth sampling point are respectively located above and below the air supply opening of the Nth-floor household or the inlet of the indoor air supply duct, where N is the total number of floors of the building; Then calculate the pressure values at the cross-sections where each sampling point in the common air supply duct is located through the following formula: P n-1 = P n + ΔP n1 + ΔP yn In the above formula, P n-1 represents the pressure value at the cross-section where the (n - 1)-th sampling point is located, P n-1 represents the pressure value at the cross-section where the n-th sampling point is located, and △P n1 represents the pressure value consumed when the fluid flows from sampling point n - 1 to sampling point n. The calculation formula of △P n1 is as follows: △P n1 = f(V n / V n内 )·V n内 ·V n内 / (L x ·L y ) In the above formula, V n and V n内 are respectively the air flow velocity at the sampling point n in the common make-up air duct and the gas flow velocity in the indoor make-up air duct on the nth floor. The function f(V n / V n内 ) is a cubic polynomial function of the variable V n / V n内 ; L x and L y are respectively the length and width of the inner cross-section of the common make-up air duct. f(V n / V n内 ) = K1 + A1·(V n / V n内 ) + B1·(V n / V n内 ) 2 + C1·(V n / V n内 ) 3 , where K1, A1, B1, and C1 are preset constants; △P yn is the frictional resistance loss along the common make-up air duct: △P yn = λ1·ρ·Q n 2 ·h*(L x + L y ) / [4·(L x ·L y ) 3 ​ In the above formula, λ1 is the friction coefficient along the common air supply duct, which is a preset value, ρ is the air density, and Q n is the exhaust air volume of the range hood in the kitchen on the nth floor, h is the storey height, and L x and L y are the length and width of the inner cross-section of the common air supply duct respectively; Through iterative calculation, use P0 = P1 + △P 11 + △P y1 , calculate P1, P2... P N ; Step 2: Calculate the internal pressure value in the indoor air supply duct of the household kitchens on each floor through the following formula: P n内 = P n-1 - ΔP n2 In the above formula, n-1 represents the pressure value at the cross-section where the (n - 1)-th sampling point is located, P n内 is the pressure value in the indoor make-up air duct of the n-th layer, △P n2 represents the total pressure difference between the cross-section where the (n - 1)-th sampling point is located in the common make-up air duct and the indoor make-up air duct of the n-th layer: △P n2 = F(V n / V n内 )·V n内 ·V n内 F(V n / V n内 ) is a cubic polynomial function of the variable V n / V n内 : F(V n / V n内 ) = K2 + A2·(V n / V n内 ) + B2·(V n / V n内 ) 2 + C2·(V n / V n内 ) 3 , where K2, A2, B2, and C2 are preset constants; Step 3: Calculate the static pressure value in the household kitchens on each floor through the following formula: P n厨房 = P n内 - P n动 - △P F - △P g P n厨房 represents the static pressure value in the kitchen of the household on the nth floor, P n动 = 0.5·ρ·V n内 ·V n内 , ρ is the air density, △P F represents the pressure loss consumed by the fluid passing through the air make-up valve, △P F = k1e k2 · (90-θ) ·(ρ·V n内 2 / 2), k1 and k2 are constants, θ is the opening angle of the air make-up valve on the nth floor, and the initial value of θ is equal to 90°; △P g represents the resistance loss that the air flow needs to overcome from the outlet of the air make-up valve to the inside of the kitchen, △P g = k·Q n 2 , k is the resistance coefficient of the indoor air make-up duct and the air make-up opening, which is a preset constant; Q n is the exhaust air volume of the range hood in the kitchen on the nth floor; Step 4. Determine whether |P| n厨房 is less than or equal to 3 Pa. If P n厨房 is less than -3 Pa, determine whether the opening angle θ of the air supply valve where the nth layer is located is less than 90°. If not, directly return to Step 1. If so, increase the opening angle of the air supply valve where the nth layer is located by 0.2°, and then return to Step 1. If P n厨房 is greater than 3 Pa, decrease the opening angle of the air supply valve where the nth layer is located by 0.2°, and then return to Step 1. If |P| n厨房 is less than or equal to 3 Pa, proceed to Step 5; Step 5: Determine whether the number of households with the final opening angle of the wind supply valve equal to 90° among all household floors is greater than 1. If not, reduce the value of P0 by 2 units, and then return to Step 1; Thus, when the calculation is completed, the make-up air system sends the opening angles of the make-up air valves in the households on each floor finally calculated to the indoor control box inside the kitchen on the nth floor; at the same time, according to the finally calculated P0, it adjusts the make-up air volume that the make-up air system needs to deliver, and uses the pressure data fed back by the pressure sensor at the inlet of the common make-up air duct to make the pressure value at the inlet of the common make-up air duct reach the finally calculated P0 value.

4. The centralized smoke exhaust and air make-up system for buildings according to claim 1, characterized in that: The make-up air openings are arranged on the ceiling, or the wall, or the cabinet of each household kitchen.

5. The centralized smoke exhaust and air supply system for buildings according to claim 1, wherein: The make-up air system is arranged in the basement of the building.

6. The centralized smoke exhaust and air supply system for buildings according to claim 5, characterized in that: The make-up air system includes a make-up air fan, a make-up air electric control system, a make-up air box and a purification filter screen. The make-up air fan is arranged inside the make-up air box. The make-up air box is provided with an air inlet and an air outlet. The purification filter screen is arranged at the air inlet. The make-up air electric control system is electrically connected to the make-up air fan and can control the air volume of the make-up air fan. The air outlet of the make-up air box is communicated with the inlet of the common make-up air duct.

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