A method for operating a building central smoke exhaust system

Abstract

The application relates to a running control method of a building centralized smoke exhaust system, wherein the building centralized smoke exhaust system comprises N indoor oil smoke exhaust fans, a public flue and an outdoor electric control device, and the method is characterized in that: after a user opens the oil smoke exhaust fan, the target air volume of the air volume gear is adjusted to be stable, and the floor position, the starting signal, the target air volume, the current air volume value and the current static pressure value are sent to the outdoor machine; the outdoor machine compares the pressure value of the current lowest starting floor flue calculated according to the information of each starting floor with the target flue pressure, and then adjusts the rotating speed of the outdoor fan. Compared with the prior art, the application has the advantages that: the static pressure of the public flue corresponding to the current lowest starting floor can be calculated based on the running condition of the starting indoor oil smoke exhaust fan, the running rotating speed of the outdoor machine is adjusted, the target air volume of the indoor oil smoke exhaust fan is dynamically adjusted, and the problem of oil smoke backflow and taste mixing can be effectively solved.

Description

Technical Field

[0001] This invention relates to an operation control method for a centralized smoke exhaust system in a building. Background Technology

[0002] Most high-rise residential buildings currently use centralized smoke extraction systems. Indoor range hoods are connected to the building's shared smoke duct via indoor pipes and check valves. Kitchen fumes are exhausted through the indoor range hoods and pipes into the shared smoke duct, from where they are finally vented outdoors. Due to the height of high-rise buildings, the shared smoke ducts are often constructed by connecting multiple sections of branch ducts. It's difficult to ensure a complete seal between these sections. Furthermore, during manufacturing and transportation, these branch ducts are prone to damage, often resulting in cracks or small holes in their walls. Therefore, when the indoor range hood exhausts smoke into the shared smoke duct, a positive pressure exists inside, exceeding the pressure in the kitchen. This causes leaks in the shared smoke duct, allowing fumes to seep into the kitchen, resulting in backdraft and odor mixing. This is the primary cause of smoke and odor mixing issues in many residential buildings.

[0003] To address the issue of backdraft and odor transfer, an outdoor exhaust fan placed at the top of the shared flue generates active suction. This, combined with the airflow adjustment of the indoor range hood, reduces the pressure inside the flue, creating a negative pressure level. This solves the problem of backdraft and odor transfer while improving the exhaust efficiency of each floor. Whether the pressure inside the shared flue can reach a completely negative state depends on the aerodynamic performance and operating power of the outdoor exhaust fan, as well as the total airflow within the flue. If the pressure inside the flue is not completely negative, the backdraft and odor transfer problem cannot be completely solved. If the negative pressure in the flue corresponding to the ground floor is high, the outdoor exhaust fan must operate at high power to alleviate the exhaust difficulty, resulting in high energy consumption and noise. Therefore, the most reasonable solution is to achieve a pressure of approximately 0 Pa at the bottom of the shared flue. This solves the backdraft and odor transfer problem, allows the outdoor unit to operate at minimum power, achieving energy saving and low-noise operation, while ensuring effective exhaust on the ground floor under near-direct exhaust conditions. However, to achieve this effect, the following issues need to be addressed:

[0004] 1. How to obtain the pressure value at the bottom of the common flue for the outdoor smoke exhaust fan and then adjust its operating power accordingly. Current technology involves installing a pressure sensor at the bottom of the common flue and sending the data collected by the sensor to the outdoor smoke exhaust fan. However, in oily fume environments, the pressure sensor has poor reliability and needs to be constantly powered on, making this method impractical in real-world situations.

[0005] 2. When the indoor range hood is frequently used and the common flue is very congested, the pressure at the bottom of the common flue is very high, and it is difficult to bring the pressure at the bottom close to 0Pa even by adjusting the power of the outdoor unit. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an operation control method for a building centralized smoke exhaust system that can prevent backdraft and cross-contamination of oil fumes and odors, in contrast to the above-mentioned prior art.

[0007] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: 1. A method for operating and controlling a centralized smoke exhaust system in a building, wherein the centralized smoke exhaust system includes N indoor range hoods installed inside the kitchens of residents on different floors, where N is a natural number; a common smoke duct installed inside the building; an outdoor fan installed on the top floor of the building; and an outdoor electrical control device. The N indoor range hoods and the outdoor fan are all communicatively connected to the outdoor electrical control device. The air outlets of the N indoor range hoods are connected to the common smoke duct through indoor smoke exhaust branch pipes, and the top air outlet of the common smoke duct is connected to the inlet of the outdoor fan. The method is characterized in that:

[0008] The outdoor electrical control device obtains and saves the resistance coefficient between the indoor range hood outlet and the common flue on each floor in advance using the following method:

[0009] After the building's centralized smoke extraction system is installed, during the commissioning phase, first turn on any one indoor range hood at any fan speed setting, while turning off all other indoor range hoods. At this time, the outdoor fans are not running. Each indoor range hood has pre-stored formulas relating fan speed to actual exhaust volume at different fan speed settings, as well as formulas relating fan speed to static pressure at the exhaust outlet. Once the indoor range hoods are running stably, the actual exhaust volume *qi* and the outlet static pressure *P0i* are calculated based on their fan speed values. Then, the indoor range hood on that floor sends the calculated actual exhaust volume *qi* and outlet static pressure *P0i* to the outdoor control unit. Upon receiving these values, the outdoor control unit processes them according to the formula *ki = P0i / qi*. 2 Calculate the ki value corresponding to the floor and save the ki value as the resistance coefficient between the indoor range hood outlet and the public flue of the corresponding floor; where i = 1, 2, ... N;

[0010] The building's centralized smoke exhaust system is operated and controlled using the following steps:

[0011] Step 1: After the indoor range hood on any floor is powered on, the user selects the fan speed setting and determines the original target air volume value at that setting. This original target air volume value is then used as the target air volume value for the indoor range hood. Then proceed to Step 2.

[0012] Step 2: The indoor range hood operates with constant air volume control based on the target air volume value until it stabilizes. At the same time, the indoor range hood on the corresponding floor sends the start signal, floor position, air volume setting selected by the user, and target air volume value to the outdoor electronic control device.

[0013] Step 3: The indoor range hoods on each floor that are in operation obtain the current fan speed, and calculate the actual exhaust volume and static pressure at the air outlet of the corresponding indoor range hood based on the current fan speed. Then, send these two data to the outdoor electrical control device.

[0014] Step 4: The outdoor electrical control device calculates the operating rate of the indoor range hoods in the entire building's centralized smoke exhaust system. The outdoor electrical control device determines whether the operating rate of the indoor range hoods is equal to 0. If so, the outdoor electrical control device controls the outdoor fan to stop running; if not, the outdoor electrical control device starts the outdoor fan and makes the outdoor fan run at the preset default speed, and then proceeds to step 5.

[0015] Step 5: The outdoor electrical control device obtains the actual exhaust volume and static pressure at the outlet of the indoor range hood on the lowest floor among all the operating indoor range hoods, based on the floor location of all operating indoor range hoods. The actual exhaust volume of the indoor range hood on the lowest operating floor is recorded as qj, and the static pressure at the outlet of the indoor range hood on the lowest operating floor is recorded as P0j. The static pressure value of the common flue corresponding to the lowest operating floor is calculated as Pj = P0j + kj × qj. 2 Where kj is the resistance coefficient between the air outlet of the indoor range hood on the lowest floor and the common flue among all the indoor range hoods that are turned on;

[0016] Step 6: The outdoor electrical control device performs the following processing based on Pj:

[0017] If |Pj| is less than or equal to 10pa, the outdoor electrical control device controls the outdoor fan to maintain the current speed, and then returns to step 2;

[0018] If Pj is greater than 10pa, proceed to step 7;

[0019] If Pj is less than -10pa, proceed to step 10;

[0020] Step 7: The outdoor electrical control device determines whether the outdoor fan speed has reached the maximum value. If yes, proceed to step 8; otherwise, the outdoor electrical control device controls the outdoor fan to increase its speed and then returns to step 2.

[0021] Step 8: The outdoor electronic control device sends a command to the indoor range hoods on each floor where the unit is turned on to reduce the target air volume value, and then proceeds to step 9;

[0022] Step 9: After receiving the instruction from the outdoor electronic control device to reduce the target air volume value, the indoor range hoods on each floor that are in operation determine whether the current air volume setting is the lowest setting. If so, the indoor range hoods maintain the original target air volume value at that setting and continue operating at the current air volume setting, then return to Step 2; otherwise, the indoor range hoods reduce the target air volume value, use the reduced target air volume value as the new target air volume value, and then return to Step 2.

[0023] Step 10: The outdoor electrical control device determines whether the target air volume value of the indoor range hood on each floor is the original target air volume value of each setting. If yes, the outdoor electrical control device controls the outdoor fan to reduce its speed and then returns to step 2; otherwise, proceed to step 11.

[0024] Step 11: The outdoor electronic control device sends a command to the indoor range hoods on each floor where the unit is turned on to increase the target air volume value, and then proceeds to step 12;

[0025] Step 12: After receiving the instruction from the outdoor electronic control device to increase the target air volume value, the indoor range hoods on each floor that are turned on determine whether the current air volume setting is the lowest setting. If so, the indoor range hoods maintain the original target air volume value at that setting and continue operating at the current air volume setting, then return to Step 2; otherwise, the indoor range hoods increase the target air volume value, use the increased target air volume value as the new target air volume value, and then return to Step 2.

[0026] The fans of N indoor range hoods are DC inverter motors. The air volume settings of the N indoor range hoods include high, medium and low. The original target air volume value corresponding to each air volume setting is preset.

[0027] Compared with the prior art, the advantages of the present invention are: it can calculate the static pressure of the common flue corresponding to the lowest floor where the indoor range hood is turned on based on the operating conditions of the indoor range hood, and then adjust the operating speed of the outdoor unit. At the same time, it can dynamically adjust the target air volume of the indoor range hood, thereby reducing the pressure of the common flue and solving the problem of backflow of cooking fumes and cross-contamination of odors. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the building centralized smoke exhaust system in an embodiment of the present invention.

[0029] Figure 2 This is a flowchart illustrating how the outdoor electrical control device acquires the resistance coefficient between the air outlet of the indoor range hood on each floor and the common flue in an embodiment of the present invention.

[0030] Figure 3 This is a flowchart of the operation control method for a centralized smoke exhaust system in a building, as described in an embodiment of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] like Figure 1 The building's centralized smoke exhaust system shown includes N indoor range hoods 1 installed inside the kitchens of residents on different floors, where N is a natural number; a public smoke duct 2 installed inside the building; an outdoor fan 3 installed on the top floor of the building; and an outdoor electrical control device 4. The N indoor range hoods 1 and the outdoor fan 3 are all connected to the outdoor electrical control device 4. The air outlets of the N indoor range hoods 1 are connected to the public smoke duct 2 through indoor smoke exhaust branch pipes 5. Each floor's indoor smoke exhaust branch pipe outlet is equipped with an air volume regulating valve 6 that can adjust the opening angle. The air outlet at the top of the public smoke duct 2 is connected to the inlet of the outdoor fan 3.

[0033] The outdoor electrical control device obtains the resistance coefficient between the indoor range hood outlet and the common flue on each floor using the following method, and saves it in advance, see [link to relevant documentation]. Figure 2 As shown:

[0034] After the building's centralized smoke extraction system is installed, during the commissioning phase, first turn on any one indoor range hood at any fan speed setting, while turning off all other indoor range hoods. At this time, the outdoor fans are not running. Each indoor range hood has pre-stored formulas relating fan speed to actual exhaust volume at different fan speed settings, as well as formulas relating fan speed to static pressure at the exhaust outlet at different fan speed settings. Once the indoor range hoods are running stably, the actual exhaust volume *qi* and the outlet static pressure *P0i* are calculated based on their fan speed values. Then, the indoor range hood on that floor sends the calculated actual exhaust volume *qi* and outlet static pressure *P0i* to the outdoor control unit. Upon receiving these values, the outdoor control unit processes them according to the formula *ki = P0i / qi*. 2 Calculate the ki value corresponding to the floor and save the ki value as the resistance coefficient between the indoor range hood outlet and the public flue of the corresponding floor; where i = 1, 2, ... N;

[0035] The building's centralized smoke exhaust system is operated and controlled using the following steps:

[0036] Step 1: After the indoor range hood on any floor is powered on, the user selects the fan speed setting and determines the original target air volume value at that setting. This original target air volume value is then used as the target air volume value for the indoor range hood. Then proceed to Step 2.

[0037] Step 2: The indoor range hoods operate using a constant airflow control method based on the target airflow value until they stabilize. At the same time, the indoor range hoods on the corresponding floors send the start signal, floor location, user-selected airflow level, and target airflow value to the outdoor electronic control device. The fans of the N indoor range hoods use DC inverter motors, and the airflow levels of the N indoor range hoods include high, medium, and low speeds. The original target airflow value for each airflow level is preset.

[0038] The control principle of the constant air volume control method is: The indoor range hood has a pre-set curve showing the fan speed versus actual exhaust volume at different air volume settings, Q = A + B × n + C × n 2 Where n is the fan speed, Q is the actual exhaust volume, and A, B, and C are preset conventional parameters; and the curve P0 = a + b × n + c × n at the indoor range hood outlet is also shown. 2 Where n is the fan speed, P0 is the actual exhaust volume, and a, b, and c are preset parameters. When the range hood is running, the current fan speed can be determined through the electromotive force of the DC inverter motor. Based on the fan speed, the actual exhaust volume q can be calculated according to the fan speed and actual exhaust volume curve for the corresponding airflow setting. The actual operating setting of the range hood is then adjusted based on the actual exhaust volume q and the target airflow value to regulate the airflow. That is, using the target airflow value and Q = A + B*n + C*n... 2 The actual required fan speed is calculated by working backwards, and the fan is then operated at the required speed. The overall idea of ​​the constant air volume control method is: when the smoke exhaust resistance is high, it operates at a high air volume setting; when the smoke exhaust resistance is low, it operates at a low current setting, and noise is reduced. Therefore, for users on higher floors, the smoke exhaust resistance is inherently lower, so the indoor range hood operates at a lower current setting. While meeting the target air volume, kitchen noise is lower, and it does not obstruct the smoke exhaust of other floors, achieving maximum smoke exhaust effect in the shared smoke duct and energy saving of the range hood.

[0039] Step 3: The indoor range hoods on each floor that are in operation obtain the current fan speed, and calculate the actual exhaust volume and static pressure at the air outlet of the corresponding indoor range hood based on the current fan speed. Then, send these two data to the outdoor electrical control device.

[0040] Step 4: The outdoor electrical control device calculates the operating rate of the indoor range hoods in the entire building's centralized smoke exhaust system. The outdoor electrical control device determines whether the operating rate of the indoor range hoods is equal to 0. If so, the outdoor electrical control device controls the outdoor fan to stop running and then returns to step 3; if not, the outdoor electrical control device starts the outdoor fan and makes the outdoor fan run at the preset default speed, and then proceeds to step 5.

[0041] Step 5: The outdoor electrical control device obtains the actual exhaust volume and static pressure at the outlet of the indoor range hood on the lowest floor among all the operating indoor range hoods, based on the floor location of all operating indoor range hoods. The actual exhaust volume of the indoor range hood on the lowest operating floor is recorded as qj, and the static pressure at the outlet of the indoor range hood on the lowest operating floor is recorded as P0j. The static pressure value of the common flue corresponding to the lowest operating floor is calculated as Pj = P0j + kj × qj. 2 Where kj is the resistance coefficient between the air outlet of the indoor range hood on the lowest floor and the common flue among all the indoor range hoods that are turned on;

[0042] Step 6: The outdoor electrical control device performs the following processing based on Pj:

[0043] If |Pj| is less than or equal to 10pa, the outdoor electrical control device controls the outdoor fan to maintain the current speed, and then returns to step 2;

[0044] If Pj is greater than 10pa, proceed to step 7;

[0045] If Pj is less than -10pa, proceed to step 10;

[0046] Step 7: The outdoor electrical control device determines whether the outdoor fan speed has reached the maximum value. If yes, proceed to step 8; otherwise, the outdoor electrical control device controls the outdoor fan to increase its speed and then returns to step 2.

[0047] Step 8: The outdoor electronic control device sends a command to the indoor range hoods on each floor where the unit is turned on to reduce the target air volume value, and then proceeds to step 9;

[0048] Step 9: After receiving the instruction from the outdoor electronic control device to reduce the target air volume value, the indoor range hoods on each floor that are in operation determine whether the current air volume setting is the lowest setting. If so, the indoor range hoods maintain the original target air volume value at that setting and continue operating at the current air volume setting, then return to Step 2; otherwise, the indoor range hoods reduce the target air volume value, use the reduced target air volume value as the new target air volume value, and then return to Step 2.

[0049] Step 10: The outdoor electrical control device determines whether the target air volume value of the indoor range hood on each floor is the original target air volume value of each setting. If yes, the outdoor electrical control device controls the outdoor fan to reduce its speed and then returns to step 2; otherwise, proceed to step 11.

[0050] Step 11: The outdoor electronic control device sends a command to the indoor range hoods on each floor where the unit is turned on to increase the target air volume value, and then proceeds to step 12;

[0051] Step 12: After receiving the instruction from the outdoor electronic control device to increase the target air volume value, the indoor range hoods on each floor that are turned on determine whether the current air volume setting is the lowest setting. If so, the indoor range hoods maintain the original target air volume value at that setting and continue operating at the current air volume setting, then return to Step 2; otherwise, the indoor range hoods increase the target air volume value, use the increased target air volume value as the new target air volume value, and then return to Step 2.

Claims

1. A method for operating and controlling a centralized smoke extraction system in a building, wherein the centralized smoke extraction system includes N indoor range hoods installed in the kitchens of residents on different floors, where N is a natural number; a common smoke duct installed inside the building; an outdoor fan installed on the top floor of the building; and an outdoor electrical control device. The N indoor range hoods and the outdoor fan are all communicatively connected to the outdoor electrical control device. The air outlets of the N indoor range hoods are connected to the common smoke duct via indoor smoke extraction branch pipes, and the top air outlet of the common smoke duct is connected to the inlet of the outdoor fan. The method is characterized in that: The outdoor electrical control device obtains and saves the resistance coefficient between the indoor range hood outlet and the common flue on each floor in advance using the following method: After the building's centralized smoke extraction system is installed, during the commissioning phase, first turn on any one indoor range hood at any fan speed setting, while turning off all other indoor range hoods. At this time, the outdoor fans are not running. Each indoor range hood has pre-stored formulas relating fan speed to actual exhaust volume at different fan speed settings, as well as formulas relating fan speed to static pressure at the exhaust outlet at different fan speed settings. Once the indoor range hoods are running stably, the actual exhaust volume *qi* and the outlet static pressure *P0i* are calculated based on their fan speed values. Then, the indoor range hood on that floor sends the calculated actual exhaust volume *qi* and outlet static pressure *P0i* to the outdoor control unit. Upon receiving these values, the outdoor control unit processes them according to the formula *ki = P0i / qi*. 2 Calculate the ki value corresponding to the floor and save the ki value as the resistance coefficient between the indoor range hood outlet and the public flue of the corresponding floor; where i = 1, 2, ... N; The building's centralized smoke exhaust system is operated and controlled using the following steps: Step 1: After the indoor range hood on any floor is powered on, the user selects the fan speed setting and determines the original target air volume value at that setting. This original target air volume value is then used as the target air volume value for the indoor range hood. Then proceed to Step 2. Step 2: The indoor range hood operates with constant air volume control based on the target air volume value until it stabilizes. At the same time, the indoor range hood on the corresponding floor sends the start signal, floor position, air volume setting selected by the user, and target air volume value to the outdoor electronic control device. Step 3: The indoor range hoods on each floor that are in operation obtain the current fan speed, and calculate the actual exhaust volume and static pressure at the air outlet of the corresponding indoor range hood based on the current fan speed. Then, send these two data to the outdoor electrical control device. Step 4: The outdoor electrical control device calculates the operating rate of the indoor range hoods in the entire building's centralized smoke exhaust system. The outdoor electrical control device determines whether the operating rate of the indoor range hoods is equal to 0. If so, the outdoor electrical control device controls the outdoor fan to stop running; if not, the outdoor electrical control device starts the outdoor fan and makes the outdoor fan run at the preset default speed, and then proceeds to step 5. Step 5: The outdoor electrical control device obtains the actual exhaust volume and static pressure at the outlet of the indoor range hood on the lowest floor among all the operating indoor range hoods, based on the floor location of all operating indoor range hoods. The actual exhaust volume of the indoor range hood on the lowest operating floor is recorded as qj, and the static pressure at the outlet of the indoor range hood on the lowest operating floor is recorded as P0j. The static pressure value of the common flue corresponding to the lowest operating floor is calculated as Pj = P0j + kj × qj. 2 Where kj is the resistance coefficient between the air outlet of the indoor range hood on the lowest floor and the common flue among all the indoor range hoods that are turned on; Step 6: The outdoor electrical control device performs the following processing based on Pj: If |Pj| is less than or equal to 10pa, the outdoor electrical control device controls the outdoor fan to maintain the current speed, and then returns to step 2; If Pj is greater than 10pa, proceed to step 7; If Pj is less than -10pa, proceed to step 10; Step 7: The outdoor electrical control device determines whether the outdoor fan speed has reached the maximum value. If yes, proceed to step 8; otherwise, the outdoor electrical control device controls the outdoor fan to increase its speed and then returns to step 2. Step 8: The outdoor electronic control device sends a command to the indoor range hoods on each floor where the unit is turned on to reduce the target air volume value, and then proceeds to step 9; Step 9: After receiving the instruction from the outdoor electronic control device to reduce the target air volume value, the indoor range hoods on each floor that are in operation determine whether the current air volume setting is the lowest setting. If so, the indoor range hoods maintain the original target air volume value at that setting and continue operating at the current air volume setting, then return to Step 2; otherwise, the indoor range hoods reduce the target air volume value, use the reduced target air volume value as the new target air volume value, and then return to Step 2. Step 10: The outdoor electrical control device determines whether the target air volume value of the indoor range hood on each floor is the original target air volume value of each setting. If yes, the outdoor electrical control device controls the outdoor fan to reduce its speed and then returns to step 2; otherwise, proceed to step 11. Step 11: The outdoor electronic control device sends a command to the indoor range hoods on each floor where the unit is turned on to increase the target air volume value, and then proceeds to step 12; Step 12: After receiving the instruction from the outdoor electronic control device to increase the target air volume value, the indoor range hoods on each floor that are turned on determine whether the current air volume setting is the lowest setting. If so, the indoor range hoods maintain the original target air volume value at that setting and continue operating at the current air volume setting, then return to Step 2; otherwise, the indoor range hoods increase the target air volume value, use the increased target air volume value as the new target air volume value, and then return to Step 2.

2. The operation control method for a centralized smoke exhaust system in a building according to claim 1, characterized in that: The fans of N indoor range hoods are DC inverter motors. The air volume settings of the N indoor range hoods include high, medium and low. The original target air volume value corresponding to each air volume setting is preset.

Images