A ventilation fan control system and its control method

Abstract

This invention discloses an exhaust fan control system and its control method. The exhaust fan control system includes a fan system, a voltage detection module, a fire level detection module, and a control module. The fan system has at least a power frequency drive circuit and a variable frequency drive circuit. The voltage detection module is used to detect the voltage parameters in the power frequency drive circuit to determine whether the power frequency drive circuit is faulty. The fire level detection module is used to detect whether a fire has occurred and the fire level if a fire occurs. The control module is used to switch the operating mode of the fan system. When a fire is detected, and the voltage detection module detects a fault in the power frequency drive circuit, the control module controls the fan system to operate in variable frequency mode and adjusts the fan speed according to the fire level. Compared with the prior art, this invention can determine whether the power frequency drive circuit is normal, thereby switching the operating mode of the fan system and ensuring the reliable operation of the fan system during a fire.

Description

Technical Field

[0001] This invention relates to the field of fire safety protection technology, and in particular to an exhaust fan control system and its control method. Background Technology

[0002] Emergency smoke extraction during fires is crucial for ensuring personnel safety and minimizing property damage. Currently, emergency smoke extraction is achieved through fan systems. These systems typically operate in two modes: fixed frequency and variable frequency. Under normal circumstances, the variable frequency mode is used for energy saving, ensuring basic ventilation and smoke extraction. In the event of a fire, the system switches to fixed frequency mode to maximize smoke extraction capacity. However, current fan systems have the following problems:

[0003] If the power frequency drive circuit fails, even if the fan system successfully switches to power frequency mode, the fan will not be able to start, which will lead to smoke exhaust failure.

[0004] If the power frequency starting circuit fails during a fire, there is a lack of effective backup operation mechanism;

[0005] In variable frequency mode, the speed control strategy of the fan system is relatively fixed and cannot be dynamically adjusted according to the smoke concentration value, which can easily lead to energy waste or insufficient smoke exhaust efficiency.

[0006] These problems can seriously affect the efficiency of personnel evacuation and rescue in emergency situations. Therefore, how to design an exhaust fan control system and its control method to ensure the reliable operation of the fan system during a fire is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0007] In view of the problem in the prior art that the exhaust fan system fails to exhaust smoke due to the failure of the power frequency drive circuit during a fire, the present invention proposes an exhaust fan control system and its control method.

[0008] The technical solution of the present invention is to propose an exhaust fan control system, including a fan system. The fan system includes at least a power frequency drive circuit for operating the fan system in power frequency mode and a variable frequency drive circuit for operating the fan system in variable frequency mode. The exhaust fan control system also includes a voltage detection module, a fire level detection module, and a control module.

[0009] The voltage detection module is installed in the power frequency drive circuit and is used to detect the voltage parameters in the power frequency drive circuit to determine whether the power frequency drive circuit is faulty.

[0010] The fire level detection module is installed in the area where the fan system is located to detect whether a fire has occurred and the fire level when a fire occurs.

[0011] The control module is used to switch the operation of the fan system in the power frequency mode or the variable frequency mode. When the fire level detection module detects a fire, the control module prioritizes controlling the fan system to operate in the power frequency mode. When the voltage detection module detects a fault in the power frequency drive circuit, the control module controls the fan system to operate in the variable frequency mode and is used to adjust the fan speed in the fan system according to the fire level.

[0012] The exhaust fan control system proposed in this invention features both a power frequency mode and a variable frequency mode. Under normal circumstances, energy-saving operation can be achieved through the variable frequency mode, while the power frequency mode ensures maximum smoke extraction capacity during a fire. Furthermore, this invention includes a voltage detection module that can detect the voltage parameters of the power frequency drive circuit to determine if a fault has occurred, thereby providing early warning or switching the operating mode to ensure reliable operation of the fan system during a fire.

[0013] Furthermore, a power frequency drive module is provided in the power frequency drive circuit, which controls the fan system to work in power frequency mode when the power frequency drive module is powered on.

[0014] The variable frequency drive circuit is equipped with a variable frequency drive module, which controls the fan system to work in variable frequency mode when the variable frequency drive module is powered on.

[0015] The power frequency drive module and the variable frequency drive module are electrically interlocked so that the power-on state of the power frequency drive module is opposite to that of the variable frequency drive module.

[0016] This invention achieves electrical interlock between the power frequency drive module and the frequency conversion drive module, thereby preventing the power supply from short-circuiting due to simultaneous power-on of the power frequency drive circuit and the frequency conversion drive circuit.

[0017] Furthermore, the fire level detection module includes at least a smoke sensor module and a human body detection module. The smoke sensor module is used to detect the smoke concentration value in the area where the fan system is located, and the human body detection module is used to detect the number of human bodies in the area where the fan system is located.

[0018] The fire level is determined based on the smoke concentration value and the number of people.

[0019] This invention determines the fire level by comprehensively considering smoke concentration and the number of people, enabling accurate prediction of fire situations and the determination of fan speed adjustment strategies. This makes the operation of the fan system more intelligent, achieving on-demand smoke extraction and improving energy efficiency.

[0020] Furthermore, the fire levels include Level 1 fire, Level 2 fire, and Level 3 fire;

[0021] When the smoke concentration is within the first threshold range and the number of people is zero, the fire level is a Level 1 fire.

[0022] When the smoke concentration is within the second threshold range and the number of people is zero, the fire level is a level two fire.

[0023] When the smoke concentration value is in the third threshold range, or when the number of people is not zero, the fire level is a level three fire.

[0024] The upper limit of the first threshold interval is lower than the lower limit of the second threshold interval, and the upper limit of the second threshold interval is lower than the lower limit of the third threshold interval.

[0025] This invention rationally classifies fire levels and provides different control strategies to suit different fire levels. It can achieve on-demand smoke extraction and improve energy efficiency, and make the fan operation more energy-efficient while ensuring basic smoke extraction capacity, thereby extending equipment life and reducing energy consumption.

[0026] Furthermore, the exhaust fan control system also includes an automatic fire alarm module, a human-machine interaction module, and an early warning module;

[0027] The automatic fire alarm module is used to output fire alarm signals, fire area signals, and fire level signals when a fire occurs.

[0028] The human-machine interaction module is used for human-machine interaction to set the operating parameters and working mode of the wind turbine system, as well as to query and display fault data.

[0029] The early warning module is used to receive instructions from the control module to realize local audible and visual early warning, as well as remote early warning from the cloud or dispatch center.

[0030] This invention, through the inclusion of an automatic fire alarm module, a human-computer interaction module, and an early warning module, enables timely reporting of fire information when a fire occurs, ensuring prompt fire rescue and preventing the fire from escalating further.

[0031] The present invention also proposes a control method using the above-mentioned exhaust fan control system, comprising:

[0032] The system can detect the smoke concentration and number of people in the area where the fan system is located in real time, and determine whether a fire has occurred.

[0033] If the determination is yes, then the voltage parameters in the power frequency drive circuit are detected, and the power frequency drive circuit is judged to be faulty based on the voltage parameters. The operation mode of the fan system is controlled according to the judgment result.

[0034] If the determination is negative, then the fan system is controlled to operate in variable frequency mode.

[0035] In this invention, the control of the exhaust fan is divided into three modes: the first is the variable frequency mode when there is no fire, the second is the variable frequency mode when there is a fire, and the third is the power frequency mode when there is a fire. The three modes can be switched reasonably according to whether there is a fire or not, and whether the power frequency drive circuit is faulty. This ensures energy-saving operation when there is no fire, maximum smoke exhaust capacity when there is a fire and the power frequency drive circuit is normal, and reliable operation of the fan system when there is a fire and the power frequency drive circuit is faulty.

[0036] Furthermore, determining whether the power frequency drive circuit is faulty based on the voltage parameters includes:

[0037] Determine whether the voltage parameter is within the target voltage range. If yes, the power frequency drive circuit is considered to be functioning normally; otherwise,

[0038] The power frequency drive circuit is then determined to be faulty.

[0039] This invention can accurately determine whether the power frequency drive circuit is faulty by detecting voltage parameters, thereby providing early warning and switching the operating mode, and ensuring the reliable operation of the fan system in the event of a fire.

[0040] Furthermore, based on the judgment result, the operating mode of the wind turbine system is controlled, including:

[0041] When the power frequency drive circuit is determined to be normal, the fan system is controlled to operate in power frequency mode;

[0042] When a fault is detected in the power frequency drive circuit, the fan system is controlled to operate in variable frequency mode.

[0043] This invention switches the operating mode during a fire based on whether the power frequency drive circuit is functioning properly. When the power frequency drive circuit is functioning properly, it ensures that the fan system operates in power frequency mode to achieve maximum smoke extraction capacity. At the same time, it ensures the reliable operation of the fan system when the power frequency drive circuit fails.

[0044] Furthermore, when the fan system operates in variable frequency mode and there is no fire in the area where the fan system is located, the control method further includes:

[0045] The system detects the smoke concentration and the number of people in the area where the fan system is located. When the smoke concentration is zero and the number of people is less than a preset threshold, the system controls the fan system to operate at a low wind speed.

[0046] When the smoke concentration is zero and the number of people is greater than a preset threshold, the fan system is controlled to operate at a medium wind speed.

[0047] When the smoke concentration value is less than the smoke concentration value that is determined to be a fire, the fan system is controlled to operate at the medium wind speed setting.

[0048] This invention dynamically adjusts the fan speed by adjusting the smoke concentration value, which can make the fan system more energy-efficient while ensuring basic smoke exhaust capacity, thus extending the life of the fan system and reducing energy consumption.

[0049] Furthermore, when the fan system operates in variable frequency mode and a fire occurs in the area where the fan system is located, the control method further includes:

[0050] Based on the preset relationship between smoke concentration and fan speed, the fan speed in the fan system is adjusted, and the direction of the fan outlet is adjusted to face the fire area.

[0051] When the fire level is level three, the human detection module is invoked to locate the trapped personnel and the location signal is transmitted synchronously to the dispatch center.

[0052] In the event of a fire, this invention can accurately locate people using a human detection module, and by adjusting the direction of the fan's outlet, it can prevent smoke from spreading to areas with people and affecting their safety.

[0053] Compared with the prior art, the present invention has at least the following beneficial effects:

[0054] 1. By setting up a voltage detection module and comparing the voltage value detected by the voltage detection module with the target voltage range, this invention can predict whether the power frequency drive circuit is faulty before a fire occurs, thereby providing early warning or switching the operating mode, and ensuring the reliable operation of the fan system when a fire occurs.

[0055] 2. This invention enables the fan system to operate in variable frequency mode when a fire occurs and the power frequency drive circuit fails, allowing the fan system to continue operating in emergency situations, thereby improving the availability and safety of the fan system under extreme conditions.

[0056] 3. This invention determines the fan speed adjustment strategy by judging the smoke concentration value and the number of people, which can make the fan system operate more intelligently, realize on-demand smoke exhaust, and improve energy efficiency;

[0057] 4. This invention dynamically adjusts the fan speed based on the smoke concentration value, which can make the fan system more energy-efficient while ensuring the basic smoke exhaust capacity, thus extending the life of the fan system and reducing energy consumption. Attached Figure Description

[0058] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0059] Figure 1 This is a schematic diagram of the drive system of the wind turbine in this invention;

[0060] Figure 2 This is a schematic diagram illustrating the electrical interlocking between the power frequency drive module and the frequency conversion drive module in this invention.

[0061] Figure 3 This is a schematic diagram of the control module in this invention;

[0062] Figure 4 This is the overall control flow of the exhaust fan control system in this invention;

[0063] Figure 5 This is a schematic diagram of the control process of the exhaust fan control system in this invention during a fire. Detailed Implementation

[0064] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0065] In view of the problem in the prior art that the fan system cannot operate due to the failure of the power frequency drive circuit during a fire, the present invention proposes an exhaust fan control system, which is used to drive the fan system to operate in variable frequency mode when a fire occurs and the power frequency drive circuit fails, so as to ensure the reliable operation of the fan system during a fire.

[0066] Therefore, the exhaust fan control system proposed in this invention includes at least a fan system, a voltage detection module, a fire level detection module, and a control module;

[0067] Please see Figure 1 The wind turbine module proposed in this invention has two drive circuits: a variable frequency drive circuit with a variable frequency drive module on the left and a power frequency drive circuit with a power frequency drive module on the right.

[0068] Normally, when there is no fire, the fan system will activate the circuit on the left side, powering on the frequency converter drive module to make the fan system run in frequency conversion mode. In this frequency conversion mode, the fan changes the frequency and voltage of the power supply through the frequency converter, thereby adjusting the fan speed and achieving precise control of the fan air volume, thus achieving the purpose of energy-saving operation.

[0069] In the event of a fire, the fan system will activate the circuit on the right side, powering on the power frequency drive module to make the fan system run in power frequency mode. In this power frequency mode, the fan runs at its highest speed, thereby ensuring maximum smoke extraction capacity.

[0070] In traditional control schemes, if the power frequency drive circuit fails, the right-side circuit will be conducting but unable to drive the fan during a fire, resulting in smoke extraction failure.

[0071] To solve the above problems, the present invention is equipped with the voltage detection module, the fire level detection module, and the control module. As mentioned above, the scenario of smoke exhaust failure includes two conditions: one is that the power frequency drive circuit is faulty, and the other is that a fire occurs. The voltage detection module in the present invention is used to determine whether the power frequency drive circuit is faulty, and the fire level detection module is used to determine whether a fire has occurred. If both conditions are met at the same time, the control module needs to be used to control the fan system to switch to variable frequency mode.

[0072] like Figure 1 As shown, the voltage detection module is installed in the power frequency drive circuit to detect the voltage parameters in the power frequency drive circuit. By judging whether the voltage parameters are within the target voltage range, it is determined whether the power frequency drive circuit is faulty. Under normal circumstances, the voltage of the power frequency drive circuit is 380V, and the target voltage range is set within 10% of the error of this voltage, that is, within 380V±10%. If the voltage parameters detected by the voltage detection module are within the target voltage range, it means that the power frequency drive circuit is normal; otherwise, it means that the power frequency drive circuit is faulty.

[0073] The variable frequency drive circuit also includes QF1 and KM1, which serve as circuit breakers and contactors for the variable frequency drive circuit and are used to control whether the variable frequency drive module is powered on.

[0074] The power frequency drive circuit also includes QF2, KM2, and FR, which serve as circuit breakers, contactors, and thermal relays for the power frequency drive circuit, and are used to control whether the power frequency drive module is powered on.

[0075] The fire level detection module is installed in the area where the fan system is located to detect whether a fire has occurred. Generally, the fire level detection module determines whether a fire has occurred based on the smoke concentration value. If the smoke concentration value reaches a certain height, it indicates that a fire has occurred in the area where the fan system is located.

[0076] In this invention, the fire level detection module is also used to determine the fire level when a fire occurs. This invention creatively correlates the smoke concentration value with the number of people to determine the fire level. Here, the fire level is used to assess the impact on the human body. If the number of people is zero, the fire level is determined normally based on the smoke concentration value. If the number of people is not zero, the fire level is directly confirmed as the highest level to avoid the danger to the human body caused by excessively high smoke concentration caused by the fire.

[0077] Therefore, the fire level detection module proposed in this invention has a smoke sensor module and a human body detection module, which are used to detect the smoke concentration value and the number of human bodies, respectively, in order to determine the fire level.

[0078] Please see Figure 3 This is a schematic diagram of the control module in the present invention. It has pin AI1 and pin DI1, which are connected to the smoke sensor module and used to obtain the smoke concentration value detected by the smoke sensor module.

[0079] The control module also has pins AI2 and DI2, which are connected to the human body detection module to obtain the number of human bodies detected by the human body detection module.

[0080] The control module has a built-in calculation program that can accurately determine whether there is a fire and the fire level after obtaining the smoke concentration value and the number of people.

[0081] In addition, the control module also has a pin AI3, which is connected to the voltage detection module to obtain the voltage parameters detected by the voltage detection module and to determine whether the power frequency drive circuit is faulty based on the voltage parameters.

[0082] Furthermore, the control module also has pins DO1 and DO3. Here, pin DO1 is used to control the frequency converter drive circuit to turn on, so that the fan system works in frequency converter mode, and pin DO3 is used to control the power frequency drive circuit to turn on, so that the fan system works in power frequency mode.

[0083] Based on the above settings, the control module can reasonably set the working mode of the fan system according to the detection results of the voltage detection module, human body detection module, and smoke sensor module.

[0084] The specific implementation mode is as follows: if no fire occurs, the frequency converter drive circuit is turned on by controlling the pin DO1 of the control module, so that the fan system works in frequency converter mode;

[0085] If a fire occurs and the power frequency drive circuit is normal, the power frequency drive circuit will be turned on through the DO3 pin of the control module, so that the fan system will work in power frequency mode.

[0086] If a fire occurs and the power frequency drive circuit fails, the variable frequency drive circuit will be turned on through the DO1 pin of the control module, so that the fan system will work in variable frequency mode.

[0087] Based on the above-mentioned settings, the present invention enables the fan system to achieve energy-saving operation through frequency conversion mode under normal conditions, ensures maximum smoke exhaust capacity when a fire occurs and the power frequency drive circuit is normal, and ensures reliable operation of the fan system when a fire occurs and the power frequency drive circuit fails.

[0088] Please see Figure 1 The present invention includes a power frequency drive module in the power frequency drive circuit, which controls the fan system to work in power frequency mode when the power frequency drive module is powered on.

[0089] The variable frequency drive circuit is equipped with a variable frequency drive module, which controls the fan system to work in variable frequency mode when the variable frequency drive module is powered on.

[0090] like Figure 1 As shown, M is the fan, and L1, L2, and L3 are the three-phase power supplies for the fan. If the variable frequency drive module and the power frequency drive module are turned on at the same time, a power short circuit will occur. To avoid this problem, the power frequency drive module and the variable frequency drive module are electrically interlocked in this invention, so that the power-on states of the power frequency drive module and the variable frequency drive module are opposite.

[0091] Please see Figure 2 This is a schematic diagram of the electrical interlocking principle in this invention. KM1 is a contactor in the frequency converter drive circuit, KM2 is a contactor in the power frequency drive circuit, A1 is the coil of contactor KM1, and A2 is the wiring of contactor KM2. Both contactors KM1 and KM2 are normally closed relays. When coil A1 is energized, contactor KM1 will be disconnected, and when coil A2 is energized, contactor KM2 will be disconnected.

[0092] By default, contactors KM1 and KM2 are both in the closed state. When the control module sends a corresponding signal to make the fan system work in frequency conversion mode, both contactor KM1 and coil A2 are energized. Because coil A2 is energized, contactor KM2 will be opened. Because contactor KM2 is opened, coil A1 will not be energized. At this time, contactor KM1 is closed and contactor KM2 is open, and their states are reversed, so that the power-on states of the power frequency drive module and the frequency conversion drive module are reversed.

[0093] Similarly, when the control module sends a corresponding signal to make the fan system work in power frequency mode, both contactor KM2 and coil A1 are energized. Because coil A1 is energized, contactor KM1 will be disconnected. Because contactor KM1 is disconnected, coil A2 will not be energized. At this time, contactor KM2 is closed and contactor KM1 is open. The two are in opposite states, which makes the power-on states of the power frequency drive module and the frequency conversion drive module opposite.

[0094] Coil A1 and coil A2 are not included here. Figure 1 The label indicates that contactor KM1 corresponds to the attached... Figure 1 Contactors KM1 and KM2 in the medium frequency converter drive circuit are attached with corresponding accessories. Figure 1 Contactor KM2 in the medium-frequency drive circuit;

[0095] This invention achieves electrical interlock between the power frequency drive module and the frequency conversion drive module, thereby preventing the power supply from short-circuiting due to simultaneous power-on of the power frequency drive circuit and the frequency conversion drive circuit.

[0096] Furthermore, the fire detection module proposed in this invention includes at least a smoke sensor module and a human body detection module. The smoke sensor module is used to detect the smoke concentration value in the area where the fan system is located, and the human body detection module is used to detect the number of human bodies in the area where the fan system is located.

[0097] The fire severity level is determined by both the smoke concentration and the number of people on the ground.

[0098] This invention creatively correlates smoke concentration with the number of people to determine the fire level. The fire level is used to assess the impact on the human body. If the number of people is zero, the fire level is determined normally based on the smoke concentration. If the number of people is not zero, the fire level is directly confirmed as the highest level to avoid the danger to the human body caused by the fire.

[0099] Under this configuration, the present invention can accurately predict fire conditions, determine the fan speed adjustment strategy, make the operation of the fan system more intelligent, realize on-demand smoke extraction, and improve energy efficiency.

[0100] The fire levels specifically include Level 1 fire, Level 2 fire, and Level 3 fire;

[0101] The criteria for classifying fires into Level 1, Level 2, and Level 3 based on smoke concentration and the number of people in the fire are as follows:

[0102] When the smoke concentration is within the first threshold range and the number of people is zero, the fire level is a Level 1 fire.

[0103] When the smoke concentration is in the second threshold range and the number of people is zero, the fire level is a level two fire.

[0104] When the smoke concentration is in the third threshold range, or when the number of people is not zero, the fire level is a level three fire.

[0105] The upper limit of the first threshold interval is lower than the lower limit of the second threshold interval, and the upper limit of the second threshold interval is lower than the lower limit of the third threshold interval.

[0106] Here, the first threshold interval, the second threshold interval, and the third threshold interval can all be set according to the actual situation and experience.

[0107] Based on the above strategies, this invention can rationally classify fire levels and provide different control strategies for different fire levels. It can not only achieve on-demand smoke extraction and improve energy efficiency, but also make the fan operation more energy-efficient while ensuring basic smoke extraction capacity, thereby extending equipment life and reducing energy consumption.

[0108] Furthermore, the exhaust fan control system proposed in this invention also includes an automatic fire alarm module, a human-machine interaction module, and an early warning module;

[0109] Among them, the automatic fire alarm module is used to output fire alarm signals, fire area signals, and fire level signals when a fire occurs;

[0110] The human-machine interaction module is used for human-machine interaction to set the operating parameters and working mode of the wind turbine system, as well as to query and display fault data;

[0111] The early warning module is used to receive instructions from the control module to realize local audible and visual early warning, as well as remote early warning from the cloud or dispatch center.

[0112] like Figure 3 As shown, the control module in this invention also has pins RS485-1, RS485-2, and DO1;

[0113] Among them, the DO1 pin of the control module is connected to the early warning module to send corresponding instructions to the early warning module. The early warning module will then provide local audible and visual early warnings, as well as remote early warnings from the cloud or dispatch center.

[0114] The RS485-1 pin is connected to the automatic fire alarm module to inform the automatic fire alarm module to output fire alarm signals, fire area signals, and fire level signals, thereby informing relevant personnel of specific fire information.

[0115] The RS485-2 pin is connected to the human-machine interface module for human-machine interaction, which allows relevant personnel to manually set the operating parameters and working modes of the wind turbine system, as well as to query and display related faults.

[0116] With the above-mentioned settings, this invention can inform on-site personnel of fire information, configure the operating parameters and working modes of the fan system to prevent the further spread of smoke and fire, and also report the fire information to relevant fire personnel for firefighting and to ensure the safety of on-site personnel.

[0117] In summary, the exhaust fan control system proposed in this invention has the following components:

[0118] The fan system, as the core component of ventilation and smoke extraction, has two operating modes: power frequency module and variable frequency mode. It can be used for ventilation and fire smoke extraction in places such as subway areas, station halls, and platforms.

[0119] The voltage detection module includes a three-phase voltage acquisition unit, a voltage comparison unit, and a data storage unit. It is mainly used to acquire the three-phase voltages A, B, and C in the power frequency drive circuit, compare them with the target voltage range, and output fault information to the control module.

[0120] Smoke sensor module: It is used to collect the smoke concentration value of the area where the fan system is located in real time. It can output analog or digital signals to the control module and supports multi-level concentration threshold settings. It can be divided into three smoke concentration thresholds: low, medium and high, to determine the fire level.

[0121] The human body detection module integrates a thermal imaging camera, an AI life detection radar, and an AI image analysis unit. Through thermal imaging feature recognition, human contour algorithms, and life feature radar detection, it accurately distinguishes between humans and non-human heat sources (such as device heating, light source heat sources, etc.) and outputs information such as the number and location of human bodies to the control module.

[0122] The variable frequency drive module includes an IGBT inverter unit, a drive protection unit, and a fire-specific mode unit. It is used to receive instructions from the control module to achieve stepless variable frequency speed regulation of the fan from 0 to 50 Hz. It has built-in fire emergency priority control logic and supports special modes such as high-speed smoke exhaust and directional smoke exhaust.

[0123] The power frequency drive module is the same as the traditional power frequency drive module, and is mainly used to ensure the maximum smoke exhaust capacity.

[0124] The automatic fire alarm module is a hard-wired communication connection with the control module, used to output fire alarm signals, fire zone signals, and fire level signals.

[0125] The human-computer interaction module consists of a touch screen and a button unit, and is used for parameter setting, mode switching, fault diagnosis, real-time data display, etc.

[0126] The system also includes a control module, which is the core of the system. It contains a curve showing the relationship between smoke concentration and fan speed, an adjustment strategy for the relationship between human density and fan speed, a voltage anomaly logic library, and fire linkage control logic. This module receives signals from each module, performs control operations, and outputs corresponding instructions.

[0127] Please see Figure 4 The present invention also proposes a control method for an exhaust fan control system, which includes:

[0128] Real-time monitoring of smoke concentration and number of people in the area where the fan system is located, and determination of whether a fire has occurred;

[0129] If the determination is yes, the voltage parameters in the power frequency drive circuit are detected, and the power frequency drive circuit is judged to be faulty based on the voltage parameters. The operation mode of the fan system is controlled according to the judgment result.

[0130] If the determination is negative, the fan system will be controlled to operate in variable frequency mode.

[0131] Under this control logic, the present invention classifies the operating conditions of the wind turbine system into three types:

[0132] The first scenario is when there is no fire, in which the control module controls the fan system to operate in variable frequency mode to achieve energy-saving operation.

[0133] The second scenario is when a fire occurs and the power frequency drive circuit is normal. In this case, the control module controls the fan system to work in power frequency mode to ensure maximum smoke extraction capacity.

[0134] The third scenario is when a fire occurs and the power frequency drive circuit fails. In this case, the control module controls the fan system to operate in variable frequency mode to ensure the reliable operation of the fan system.

[0135] The logic for determining whether the power frequency drive circuit is faulty based on voltage parameters in the above scheme is as follows:

[0136] Determine whether the voltage parameters are within the target voltage range;

[0137] If so, the power frequency drive circuit is considered to be normal;

[0138] If not, then the power frequency drive circuit is determined to be faulty.

[0139] Normally, the voltage of the power frequency drive circuit is 380V, and the target voltage range is set within 10% of the error of this voltage, that is, within 380V±10%. If the voltage parameter detected by the voltage detection module is within the target voltage range, it means that the power frequency drive circuit is normal; otherwise, it means that the power frequency drive circuit is faulty.

[0140] Based on the above logic, this invention can accurately determine whether the power frequency drive circuit is faulty by detecting voltage parameters, thereby providing early warning and switching the operating mode to ensure that the fan system operates in variable frequency mode during a fire, thus ensuring the reliable operation of the fan system.

[0141] Furthermore, the above scheme controls the operating mode of the wind turbine system based on the judgment result, including:

[0142] When the power frequency drive circuit is determined to be normal, the control fan system operates in power frequency mode.

[0143] When a fault is detected in the power frequency drive circuit, the control fan system will operate in variable frequency mode.

[0144] In the event of a fire, if the power frequency drive circuit is normal, the fan system can operate in power frequency mode to achieve maximum smoke extraction capacity. If the power frequency drive circuit fails, the fan system can operate in variable frequency mode to ensure reliable operation of the fan system.

[0145] The working modes of the fan system under various conditions of the present invention are described below;

[0146] When there is no fire in the area where the fan system is located, this invention allows the fan system to operate in variable frequency mode. In this mode, the smoke concentration in the area is very low, and the fan speed is adjusted primarily based on the number of people in the area. Specifically:

[0147] 1. Zero smoke concentration and low human density (number of people less than the preset threshold): The control module controls the fan system to run at a low wind speed. At this time, the fan runs at 20%~40% of the rated speed to achieve energy-saving ventilation.

[0148] 2. Zero smoke concentration and high human density (number of people ≥ preset threshold): The control module controls the fan system to operate at medium wind speed, and the fan operates at 40%~70% of rated speed to increase ventilation.

[0149] 3. Low smoke concentration (smoke is present, but below the smoke concentration value for determining a fire): In this case, smoke extraction is required first. The fan system is directly controlled to run at medium speed, and the fan runs at 50%~80% of its rated speed to accelerate the diffusion and extraction of smoke.

[0150] During the above operation, the control module is also used to compare the voltage parameters detected by the voltage detection module with the target voltage range to prepare for whether to switch to the power frequency mode in the event of a fire. If the overvoltage parameter is within the target voltage range, it indicates that the power frequency drive circuit is normal. If a fire occurs at this time, the fan system will be operated in the power frequency mode. Otherwise, a voltage abnormality warning needs to be triggered. If a fire occurs at this time, the fan system will be operated in the variable frequency mode.

[0151] In the event of a fire, the control module first determines whether the power frequency drive circuit is faulty based on the voltage parameters detected by the voltage detection module. If the voltage parameter is within the range of 380V±10%, the power frequency drive circuit is considered normal; otherwise, it indicates an abnormality, and this abnormality is reported. Upon receiving an abnormality report, the control module performs further checks to determine if the power frequency drive circuit is faulty. It first checks the opening and closing status of circuit breaker QF2 (monitored via the auxiliary contacts of circuit breaker QF2). If it shows the open status, the control module executes a remote closing action. After circuit breaker QF2 closes, the voltage parameters of the power frequency drive circuit are checked again. If the voltage parameter returns to the target voltage range, the power frequency drive circuit is considered normal, and the fan system is controlled to operate in power frequency mode to improve smoke extraction. Conversely, if the voltage parameter still exceeds the target voltage range after the second check, the power frequency drive circuit is determined to be faulty, the control module executes a switching command to maintain the fan system in variable frequency mode, and simultaneously activates the fire emergency mode.

[0152] In the fire emergency mode, which occurs when a fire breaks out and the power frequency drive module fails, the fan system operates in variable frequency mode. To prevent further smoke spread, this invention also requires adjustments to the fan speed and the direction of the fan outlet. The specific strategy is as follows:

[0153] First, the fire level is determined based on the smoke sensor module and the human body detection module. If it is a level one fire, the control system controls the fan speed corresponding to the smoke concentration value to directionally exhaust smoke to the fire area. At the same time, combined with the human body position signal from the human body detection module, the direction of the fan outlet is adjusted to achieve precise smoke exhaust.

[0154] If it is a level 2 fire: the control system controls the fan speed corresponding to the smoke concentration value to directionally exhaust smoke to the fire area. At the same time, it combines the human position signal of the human body detection module to adjust the direction of the fan outlet for precise smoke exhaust.

[0155] If it is a level 3 fire: the control module will start the fire-specific high-speed mode for smoke extraction. At the same time, the control module will call the human search and rescue mode. The thermal imaging camera of the human detection module will work together with the life detection radar to lock the location of the trapped people and transmit the location signal to the dispatch center simultaneously. While the fan keeps running at high speed, it will reduce the wind speed in the surrounding area to prevent smoke from spreading to the personnel area.

[0156] The aforementioned control strategies can be stored in a corresponding storage medium and connected to the control module, which can then execute the corresponding control actions.

[0157] like Figure 5 As shown, this is the control process during a fire. It first determines whether the power frequency drive circuit is faulty by judging whether the voltage parameters of the power frequency drive circuit are within the target voltage range.

[0158] If the determination is yes, then the power frequency mode is activated, at which time the fan runs at the highest speed (the fan operating frequency range is 0~50Hz, and the highest speed corresponds to an operating frequency of 50Hz).

[0159] If the result is negative, the frequency conversion mode is maintained, and the fire level is determined based on the smoke concentration value detected by the smoke sensor module and the result of the human body detection module detecting whether anyone is trapped.

[0160] Among them, when the smoke concentration is low (corresponding to the first threshold range) and no one is trapped, it is judged as a level one fire;

[0161] If the smoke concentration is medium (corresponding to the second threshold range) and no one is trapped, it is determined to be a level two fire;

[0162] A fire is classified as a Level 3 fire if the smoke concentration is high (corresponding to the third threshold range) or if someone is trapped.

[0163] In both Level 1 and Level 2 fires, smoke is exhausted based on the fan speed corresponding to the smoke concentration value.

[0164] In the case of a level 3 fire, smoke extraction is carried out using a dedicated high-speed fire extraction mode.

[0165] After the smoke is cleared, the control logic is completed.

[0166] The present invention performs the following during the entire control process:

[0167] 1. Electrical Interlock: The power frequency drive module and the variable frequency drive module are electrically interlocked to prevent power short circuit;

[0168] 2. Signal Interlock: Fire signals are set to have higher priority than all sensor signals. Once a fire is detected, the normal ventilation strategy is immediately terminated and the system is switched to fire emergency mode.

[0169] 3. Data linkage: The human body detection module and the smoke sensor module are linked. When the smoke concentration increases or a human body is detected, the fan speed is increased and smoke is directionally exhausted. In addition, if the current fire level is level one or two, once a person is detected, the control module immediately assesses the fire level as level three and issues a corresponding instruction to control the fan system according to the level three fire.

[0170] Based on the above settings, the present invention has at least the following beneficial effects:

[0171] 1. By setting up a voltage detection module and comparing the voltage value detected by the voltage detection module with the target voltage range, this invention can predict whether the power frequency drive circuit is faulty before a fire occurs, thereby providing early warning or switching the operating mode, and ensuring the reliable operation of the fan system when a fire occurs.

[0172] 2. This invention enables the fan system to operate in variable frequency mode when a fire occurs and the power frequency drive circuit fails, allowing the fan system to continue operating in emergency situations, thereby improving the availability and safety of the fan system under extreme conditions.

[0173] 3. This invention determines the fan speed adjustment strategy by judging the smoke concentration value and the number of people, which can make the fan system operate more intelligently, realize on-demand smoke exhaust, and improve energy efficiency;

[0174] 4. This invention dynamically adjusts the fan speed based on the smoke concentration value, which can make the fan system more energy-efficient while ensuring the basic smoke exhaust capacity, thus extending the life of the fan system and reducing energy consumption.

[0175] Among them, the fan system in the above-mentioned exhaust fan control system can also be an energy-saving fan in the high-efficiency energy-saving industry, which can control smoke removal while saving energy.

[0176] It should be noted that the terminology used above is for describing specific embodiments only and is not intended to limit the exemplary embodiments of the present invention. When the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. The order of execution of actions, steps, etc., in the apparatus and methods described in the specification and drawings can be implemented in any order unless a specific order is expressly specified, and as long as the output of the preceding process is not used in the subsequent process. Similar sequential terms used for ease of description do not imply that such an order must be followed.

[0177] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as constraints. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0178] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ventilation fan control system, comprising a fan system, the fan system including at least a power frequency drive circuit for operating the fan system in a power frequency mode and a variable frequency drive circuit for operating the fan system in a variable frequency mode, characterized in that, The exhaust fan control system also includes a voltage detection module, a fire level detection module, and a control module; The voltage detection module is installed in the power frequency drive circuit and is used to detect the voltage parameters in the power frequency drive circuit to determine whether the power frequency drive circuit is faulty. The fire level detection module is installed in the area where the fan system is located to detect whether a fire has occurred and the fire level when a fire occurs. The control module is used to switch the operation of the fan system in the power frequency mode or the variable frequency mode. When the fire level detection module detects a fire, the control module prioritizes controlling the fan system to operate in the power frequency mode. When the voltage detection module detects a fault in the power frequency drive circuit, the control module controls the fan system to operate in the variable frequency mode and is used to adjust the fan speed in the fan system according to the fire level.

2. The exhaust fan control system according to claim 1, characterized in that, The power frequency drive circuit is equipped with a power frequency drive module, which controls the fan system to work in power frequency mode when the power frequency drive module is powered on. The variable frequency drive circuit is equipped with a variable frequency drive module, which controls the fan system to work in variable frequency mode when the variable frequency drive module is powered on. The power frequency drive module and the variable frequency drive module are electrically interlocked so that the power-on state of the power frequency drive module is opposite to that of the variable frequency drive module.

3. The exhaust fan control system according to claim 1, characterized in that, The fire level detection module includes at least a smoke sensor module and a human body detection module. The smoke sensor module is used to detect the smoke concentration value in the area where the fan system is located, and the human body detection module is used to detect the number of human bodies in the area where the fan system is located. The fire level is determined based on the smoke concentration value and the number of people.

4. The exhaust fan control system according to claim 3, characterized in that, The fire levels include Level 1 fire, Level 2 fire, and Level 3 fire; When the smoke concentration is within the first threshold range and the number of people is zero, the fire level is a Level 1 fire. When the smoke concentration is within the second threshold range and the number of people is zero, the fire level is a level two fire. When the smoke concentration value is in the third threshold range, or when the number of people is not zero, the fire level is a level three fire. The upper limit of the first threshold interval is lower than the lower limit of the second threshold interval, and the upper limit of the second threshold interval is lower than the lower limit of the third threshold interval.

5. The exhaust fan control system according to claim 1, characterized in that, The exhaust fan control system also includes an automatic fire alarm module, a human-machine interaction module, and an early warning module; The automatic fire alarm module is used to output fire alarm signals, fire area signals, and fire level signals when a fire occurs. The human-machine interaction module is used for human-machine interaction to set the operating parameters and working mode of the wind turbine system, as well as to query and display fault data. The early warning module is used to receive instructions from the control module to realize local audible and visual early warning, as well as remote early warning from the cloud or dispatch center.

6. A control method employing the exhaust fan control system as described in any one of claims 1 to 5, characterized in that, include: The system can detect the smoke concentration and number of people in the area where the fan system is located in real time, and determine whether a fire has occurred. If the determination is yes, then the voltage parameters in the power frequency drive circuit are detected, and the power frequency drive circuit is judged to be faulty based on the voltage parameters. The operation mode of the fan system is controlled according to the judgment result. If the determination is negative, then the fan system is controlled to operate in variable frequency mode.

7. The control method of the exhaust fan control system according to claim 6, characterized in that, Determining whether the power frequency drive circuit is faulty based on the voltage parameters includes: Determine whether the voltage parameter is within the target voltage range. If it is, the power frequency drive circuit is considered to be normal; otherwise, the power frequency drive circuit is considered to be faulty.

8. The control method of the exhaust fan control system according to claim 7, characterized in that, Controlling the operating mode of the wind turbine system based on the judgment result includes: When the power frequency drive circuit is determined to be normal, the fan system is controlled to operate in power frequency mode; When a fault is detected in the power frequency drive circuit, the fan system is controlled to operate in variable frequency mode.

9. The control method of the exhaust fan control system according to claim 8, characterized in that, When the fan system operates in variable frequency mode and there is no fire in the area where the fan system is located, the control method further includes: The system detects the smoke concentration and the number of people in the area where the fan system is located. When the smoke concentration is zero and the number of people is less than a preset threshold, the system controls the fan system to operate at a low wind speed. When the smoke concentration is zero and the number of people is greater than a preset threshold, the fan system is controlled to operate at a medium wind speed. When the smoke concentration value is less than the smoke concentration value that is determined to be a fire, the fan system is controlled to operate at the medium wind speed setting.

10. The control method of the exhaust fan control system according to claim 8, characterized in that, When the fan system is operating in variable frequency mode and a fire occurs in the area where the fan system is located, the control method further includes: Based on the preset relationship between smoke concentration and fan speed, the fan speed in the fan system is adjusted, and the direction of the fan outlet is adjusted to face the fire area. When the fire level is level three, the human detection module is invoked to locate the trapped personnel and the location signal is transmitted synchronously to the dispatch center.

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