A method for operating a building central smoke exhaust system

Abstract

This invention relates to an operation control method for a centralized smoke extraction system in a building, wherein the centralized smoke extraction system includes an indoor range hood, a common smoke duct, an outdoor fan, and an outdoor electrical control device. The key feature is that the indoor range hood's critical fan speed N is pre-recorded at different fan speed settings when the resistance at the range hood outlet is 0 Pa. Amin The indoor range hood uses the current fan speed and the critical value N of the fan speed at the corresponding air volume setting as the basis for its operation. Amin Compare the values ​​to determine if the airflow regulating valve needs adjustment. If it is less than N... Amin This indicates that a negative pressure has appeared at the air outlet of the indoor range hood. At this point, the opening angle of the airflow regulating valve is reduced. Compared with existing technologies, the advantages of this invention are: it can effectively reduce the exhaust resistance of the indoor range hood and effectively prevent abnormal operating noise caused by a negative pressure value at the air outlet during operation.

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 common smoke duct via indoor ducts and check valves. Kitchen fumes are exhausted through the indoor range hoods and ducts into the common smoke duct, and then from there to the outside. Currently, centralized smoke extraction systems often experience problems with poor ventilation during peak cooking times, especially for lower floors where ventilation resistance is higher. To address these issues, some manufacturers have developed auxiliary smoke extraction devices. These devices use outdoor exhaust fans placed at the top of the common smoke duct to generate active suction, which, in conjunction with the adjustable airflow of the indoor range hoods, achieves balanced smoke extraction across all floors, improving overall smoke extraction efficiency. Centralized smoke extraction systems with auxiliary smoke extraction devices mainly employ two methods to regulate airflow. One method uses an outdoor smoke extraction fan to generate suction, combined with resistance adjustment via an indoor electric valve, to achieve increased and balanced airflow across floors. This method primarily adjusts the outdoor smoke extraction fan's speed based on its operating rate. However, this approach has several drawbacks: it cannot accurately control indoor airflow, and the outdoor smoke extraction fan's speed doesn't account for changes in front-end resistance. This means that even when the outdoor smoke extraction fan's filter is clogged, it still operates at the preset speed, reducing the auxiliary smoke extraction effect. Furthermore, the resistance adjustment of the electric valve consumes additional energy, hindering energy conservation. The other method combines outdoor smoke extraction fan suction with variable frequency control of the indoor range hood. However, this method suffers from several problems: when the outdoor smoke extraction fan's suction is high, a significant negative pressure value appears at the indoor range hood's outlet (especially in high-rise buildings), resulting in poor noise quality and impacting the user experience. Summary of the Invention

[0003] 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 abnormal noise caused by negative pressure at the air outlet of the indoor range hood during operation, in contrast to the above-mentioned prior art.

[0004] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: 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 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 through indoor smoke exhaust branch pipes. Each floor's indoor smoke exhaust branch pipe outlet is equipped with an adjustable airflow regulating valve. The top outlet of the common smoke duct is connected to the inlet of the outdoor fan. The key feature is that the critical fan speed N for each indoor range hood is pre-recorded at different airflow levels when the resistance at the indoor range hood outlet is 0 Pa. Amin The building's centralized smoke exhaust system is operated and controlled using the following steps:

[0005] Step 1: After the indoor range hood on any floor is powered on, the user selects the fan speed level and adjusts the opening angle of the corresponding floor's fan speed regulating valve to 90°. At the same time, the indoor range hood on the corresponding floor sends the power-on signal, floor location, and the fan speed level selected by the user to the outdoor electronic control device. The indoor range hood determines the target fan speed range value for the selected fan speed level based on the user's selection and operates the range hood at the fan speed level selected by the user.

[0006] Step 2: Obtain the current fan speed of the indoor range hoods on each floor where the machine is running, and calculate the corresponding actual exhaust volume based on the current fan speed;

[0007] Step 3: Determine whether the current fan speed of the indoor range hood on each floor is less than the critical fan speed N of the corresponding indoor range hood at the corresponding airflow setting. Amin If so, reduce the opening angle of the air volume regulating valve on the corresponding floor by 2°, and then return to step 2; otherwise, proceed to step 4.

[0008] Step 4: Determine whether the actual exhaust volume of the indoor range hoods on each operating floor is within the target air volume range for the corresponding air volume setting. If so, the indoor range hoods on each operating floor continue to operate at the current air volume setting, and then return to Step 2. If the actual exhaust volume of the indoor range hoods on each operating floor is less than the minimum value in the target air volume range for the corresponding air volume setting, proceed to Step 5. If the actual exhaust volume of the indoor range hoods on each operating floor is greater than the maximum value in the target air volume range for the corresponding air volume setting, proceed to Step 7.

[0009] Step 5: Determine if the opening angle of the air volume regulating valve for the corresponding floor is equal to 90°. If yes, proceed to step 6; otherwise, adjust the opening angle of the air volume regulating valve for the corresponding floor to 90° first, and then return to step 2.

[0010] Step 6: Determine if the current airflow setting of the indoor range hood on the corresponding floor is at its maximum. If yes, continue to run the indoor range hoods on each floor at their current airflow setting, and then return to Step 2. If no, increase the airflow setting of the indoor range hood on the corresponding floor by one level, set the updated airflow setting as the current airflow setting of the indoor range hood on the corresponding floor, and then return to Step 2.

[0011] Step 7: Determine if the current airflow setting of the indoor range hood on the corresponding floor is at the minimum setting. If yes, continue to run the indoor range hoods on each floor at the current airflow setting, and then return to Step 2. If no, reduce the airflow setting of the indoor range hood on the corresponding floor by one level, set the updated airflow setting as the current airflow setting of the indoor range hood on the corresponding floor, and then return to Step 2.

[0012] As an improvement, when the indoor range hoods on all floors that are in operation are started, they send their start-up information to the outdoor electrical control device. The outdoor electrical control device then controls the operation of the outdoor fan through the following steps:

[0013] Step a: The outdoor electrical control device calculates the operating rate of the indoor range hoods in the entire building's centralized smoke exhaust system and determines the target negative pressure value P0 at the corresponding operating rate;

[0014] Step b: The outdoor electrical control device determines whether the indoor range hood's operating rate is less than 5%. If so, the outdoor electrical control device stops the outdoor fan; if not, the outdoor electrical control device starts the outdoor fan and then proceeds to step c.

[0015] Step c: The outdoor electrical control device monitors the wind pressure value P at the inlet of the outdoor fan in real time, and then proceeds to step d;

[0016] Step d: The outdoor electrical control device performs the following processing based on the wind pressure value P at the outdoor fan inlet and the target negative pressure value P0 at the current operating rate:

[0017] If |P-P0| 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 a;

[0018] If |P|-|P0| is greater than 10pa, the outdoor electrical control device controls the outdoor fan to reduce its speed and then returns to step a;

[0019] If |P|-|P0| is less than -10pa, the outdoor electrical control device controls the outdoor fan to increase its speed and then returns to step a.

[0020] As a preferred option, when the operating rate of the indoor range hood is greater than or equal to 5% and less than 10%, the target negative pressure value P0 is equal to -60Pa; when the operating rate of the indoor range hood is greater than or equal to 10% and less than 20%, the target negative pressure value P0 is equal to -120Pa; when the operating rate of the indoor range hood is greater than or equal to 20% and less than 30%, the target negative pressure value P0 is equal to -160Pa; and when the operating rate of the indoor range hood is greater than or equal to 30%, the target negative pressure value P0 is equal to -200Pa.

[0021] Compared with the prior art, the advantages of the present invention are: the indoor range hood uses the current fan speed and the critical value N of the fan speed at the corresponding air volume setting. Amin Compare the values ​​to determine if the airflow regulating valve needs adjustment. If it is less than N... Amin This indicates that there is negative pressure at the air outlet of the indoor range hood. At this time, by reducing the opening angle of the air volume regulating valve, the smoke exhaust resistance of the corresponding floor can be reduced, thereby preventing the indoor range hood from making abnormal noises due to negative pressure at its air outlet during operation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a centralized smoke exhaust system for buildings in an embodiment of the present invention.

[0023] Figure 2 This is a flowchart illustrating the operation and control of a centralized smoke exhaust system in a building, as described in this embodiment of the invention.

[0024] Figure 3 This is a flowchart illustrating how the outdoor electrical control device controls the operation of the outdoor fan in an embodiment of the present invention. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] 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.

[0027] During the airflow testing phase of the building's centralized smoke exhaust system, the critical fan speed N for each indoor range hood was pre-recorded at different airflow levels when the resistance at the range hood's outlet was 0 Pa. Amin Furthermore, each indoor range hood 1 has a pre-stored formula relating the fan speed to the actual exhaust volume at different fan speed settings; when the indoor range hood is running, the current speed value can be determined by the electromotive force of the motor, and thus the current actual exhaust volume value can be calculated.

[0028] The building's centralized smoke exhaust system is operated and controlled using the following steps, see [link to relevant documentation]. Figure 2 As shown:

[0029] Step 1: After the indoor range hood on any floor is powered on, the user selects the fan speed level and adjusts the opening angle of the corresponding floor's fan speed regulating valve to 90°. At the same time, the indoor range hood on the corresponding floor sends the power-on signal, floor location, and the fan speed level selected by the user to the outdoor electronic control device. The indoor range hood determines the target fan speed range value for the selected fan speed level based on the user's selection and operates the range hood at the fan speed level selected by the user.

[0030] Step 2: Obtain the current fan speed of the indoor range hoods on each floor where the machine is running, and calculate the corresponding actual exhaust volume based on the current fan speed;

[0031] Step 3: Determine whether the current fan speed of the indoor range hood on each floor is less than the critical fan speed N of the corresponding indoor range hood at the corresponding airflow setting. Amin If so, reduce the opening angle of the air volume regulating valve on the corresponding floor by 2°, and then return to step 2; otherwise, proceed to step 4.

[0032] Step 4: Determine whether the actual exhaust volume of the indoor range hoods on each operating floor is within the target air volume range for the corresponding air volume setting. If so, the indoor range hoods on each operating floor continue to operate at the current air volume setting, and then return to Step 2. If the actual exhaust volume of the indoor range hoods on each operating floor is less than the minimum value in the target air volume range for the corresponding air volume setting, proceed to Step 5. If the actual exhaust volume of the indoor range hoods on each operating floor is greater than the maximum value in the target air volume range for the corresponding air volume setting, proceed to Step 7.

[0033] Step 5: Determine if the opening angle of the air volume regulating valve for the corresponding floor is equal to 90°. If yes, proceed to step 6; otherwise, adjust the opening angle of the air volume regulating valve for the corresponding floor to 90° first, and then return to step 2.

[0034] Step 6: Determine if the current airflow setting of the indoor range hood on the corresponding floor is at its maximum. If yes, continue to run the indoor range hoods on each floor at their current airflow setting, and then return to Step 2. If no, increase the airflow setting of the indoor range hood on the corresponding floor by one level, set the updated airflow setting as the current airflow setting of the indoor range hood on the corresponding floor, and then return to Step 2.

[0035] Step 7: Determine if the current airflow setting of the indoor range hood on the corresponding floor is at the minimum setting. If yes, continue to run the indoor range hoods on each floor at the current airflow setting, and then return to Step 2. If no, reduce the airflow setting of the indoor range hood on the corresponding floor by one level, set the updated airflow setting as the current airflow setting of the indoor range hood on the corresponding floor, and then return to Step 2.

[0036] In addition, when the indoor range hoods on all floors that are in operation are started, they send their start-up information to the outdoor electrical control device. The outdoor electrical control device then controls the operation of the outdoor fan through the following steps, see [link to relevant documentation]. Figure 3 As shown:

[0037] Step a: The outdoor electrical control device calculates the operating rate of the indoor range hoods in the entire building's centralized smoke exhaust system and determines the target negative pressure value P0 at the corresponding operating rate;

[0038] Step b: The outdoor electrical control device determines whether the indoor range hood's operating rate is less than 5%. If so, the outdoor electrical control device stops the outdoor fan; if not, the outdoor electrical control device starts the outdoor fan and then proceeds to step c.

[0039] Step c: The outdoor electrical control device monitors the wind pressure value P at the inlet of the outdoor fan in real time, and then proceeds to step d;

[0040] Step d: The outdoor electrical control device performs the following processing based on the wind pressure value P at the outdoor fan inlet and the target negative pressure value P0 at the current operating rate:

[0041] If |P-P0| 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 a;

[0042] If |P|-|P0| is greater than 10pa, the outdoor electrical control device controls the outdoor fan to reduce its speed and then returns to step a;

[0043] If |P|-|P0| is less than -10pa, the outdoor electrical control device controls the outdoor fan to increase its speed and then returns to step a.

[0044] When the operating rate of the indoor range hood is greater than or equal to 5% but less than 10%, the target negative pressure value P0 is -60Pa; when the operating rate of the indoor range hood is greater than or equal to 10% but less than 20%, the target negative pressure value P0 is -120Pa; when the operating rate of the indoor range hood is greater than or equal to 20% but less than 30%, the target negative pressure value P0 is -160Pa; when the operating rate of the indoor range hood is greater than or equal to 30%, the target negative pressure value P0 is -200Pa.

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. Each floor's indoor smoke extraction branch pipe outlet is equipped with an adjustable airflow regulating valve with an adjustable opening angle. The top outlet of the common smoke duct is connected to the inlet of the outdoor fan. The method is characterized by: The critical fan speed N for the indoor range hood was pre-recorded at different fan speed settings when the resistance at the air outlet of the indoor range hood was 0 Pa. Amin 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 level and adjusts the opening angle of the corresponding floor's fan speed regulating valve to 90°. At the same time, the indoor range hood on the corresponding floor sends the power-on signal, floor location, and fan speed level selected by the user to the outdoor electronic control device. The indoor range hood determines the target airflow range value for the selected airflow level based on the user's choice of airflow level, and ensures that the range hood operates at the airflow level selected by the user. Step 2: Obtain the current fan speed of the indoor range hoods on each floor where the machine is running, and calculate the corresponding actual exhaust volume based on the current fan speed; Step 3: Determine whether the current fan speed of the indoor range hood on each floor is less than the critical fan speed N of the corresponding indoor range hood at the corresponding airflow setting. Amin If so, reduce the opening angle of the air volume regulating valve on the corresponding floor by 2°, and then return to step 2; otherwise, proceed to step 4. Step 4: Determine whether the actual exhaust volume of the indoor range hoods on each operating floor is within the target air volume range for the corresponding air volume setting. If so, the indoor range hoods on each operating floor continue to operate at the current air volume setting, and then return to Step 2. If the actual exhaust volume of the indoor range hoods on each operating floor is less than the minimum value in the target air volume range for the corresponding air volume setting, proceed to Step 5. If the actual exhaust volume of the indoor range hoods on each operating floor is greater than the maximum value in the target air volume range for the corresponding air volume setting, proceed to Step 7. Step 5: Determine if the opening angle of the air volume regulating valve for the corresponding floor is equal to 90°. If yes, proceed to step 6; otherwise, adjust the opening angle of the air volume regulating valve for the corresponding floor to 90° first, and then return to step 2. Step 6: Determine if the current airflow setting of the indoor range hood on the corresponding floor is at its maximum. If yes, continue to run the indoor range hoods on each floor at their current airflow setting, and then return to Step 2. If no, increase the airflow setting of the indoor range hood on the corresponding floor by one level, set the updated airflow setting as the current airflow setting of the indoor range hood on the corresponding floor, and then return to Step 2. Step 7: Determine if the current airflow setting of the indoor range hood on the corresponding floor is at the minimum setting. If yes, continue to run the indoor range hoods on each floor at the current airflow setting, and then return to Step 2. If no, reduce the airflow setting of the indoor range hood on the corresponding floor by one level, set the updated airflow setting as the current airflow setting of the indoor range hood on the corresponding floor, 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: When the indoor range hoods on all floors that are in operation are started, they send their start-up information to the outdoor electrical control device. The outdoor electrical control device then controls the operation of the outdoor fan through the following steps: Step a: The outdoor electrical control device calculates the operating rate of the indoor range hoods in the entire building's centralized smoke exhaust system and determines the target negative pressure value P0 at the corresponding operating rate; Step b: The outdoor electrical control device determines whether the indoor range hood's operating rate is less than 5%. If so, the outdoor electrical control device stops the outdoor fan; if not, the outdoor electrical control device starts the outdoor fan and then proceeds to step c. Step c: The outdoor electrical control device monitors the wind pressure value P at the inlet of the outdoor fan in real time, and then proceeds to step d; Step d: The outdoor electrical control device performs the following processing based on the wind pressure value P at the outdoor fan inlet and the target negative pressure value P0 at the current operating rate: If |P-P0| 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 a; If |P|-|P0| is greater than 10pa, the outdoor electrical control device controls the outdoor fan to reduce its speed and then returns to step a; If |P|-|P0| is less than -10pa, the outdoor electrical control device controls the outdoor fan to increase its speed and then returns to step a.

3. The operation control method for a centralized smoke exhaust system in a building according to claim 2, characterized in that: When the operating rate of the indoor range hood is greater than or equal to 5% but less than 10%, the target negative pressure value P0 is -60Pa; when the operating rate of the indoor range hood is greater than or equal to 10% but less than 20%, the target negative pressure value P0 is -120Pa; when the operating rate of the indoor range hood is greater than or equal to 20% but less than 30%, the target negative pressure value P0 is -160Pa; when the operating rate of the indoor range hood is greater than or equal to 30%, the target negative pressure value P0 is -200Pa.

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