Environment-friendly fan intelligent control system and method based on production line load

Abstract

The invention discloses an environment-friendly fan intelligent control system and method based on production line loads, and belongs to the technical field of industrial automation control. The method comprises the steps that the operation state of each production line is collected in real time; according to the number of the operation production lines, determining a fan target frequency according to a preset mapping relation and controlling a frequency converter to adjust; the corresponding air door is opened immediately when the production line is started, and the corresponding air door is closed after the production line stops and is delayed for preset time. The system comprises a state detection module, a central control unit, a fan driving module and an air door execution module. According to the method, automatic matching of the fan frequency and the production load and intelligent linkage and delayed closing of the air door and the production line are achieved, the problems that a traditional control mode is high in energy consumption, slow in response and poor in collaboration are solved, and the technical effects that energy is remarkably saved, response is fast, and the safety and the automation level are improved are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial automation control, in particular to an environmental protection fan intelligent control system and method for a chemical fiber production line, and especially to a control scheme for automatically adjusting the operating frequency of a fan according to the number of start and stop of the production line and cooperatively linking the damper. BACKGROUND

[0002] In the production process of chemical fibers, processes such as drafting and winding will generate a large amount of heat, oil mist and short fiber dust, and a powerful environmental protection exhaust system is needed to extract and exhaust to ensure the cleanliness of the production environment and the normal operation of the equipment. The traditional environmental protection fan control system has the following defects: Strong dependence on manual operation and low energy efficiency: The operating speed (frequency) of the fan is usually manually set at a fixed value or roughly adjusted by experience. When the production load changes (such as part of the production line starts and stops), the fan cannot be adjusted in time, often in a high energy consumption state of "big horse pulling small cart", causing huge waste of electric energy.

[0003] Response lag and extensive control: After the operator discovers the production change, the fan is adjusted, which has a significant time delay. And the adjustment is usually based on subjective feeling, which cannot accurately match the actual exhaust volume required.

[0004] Lack of linkage and safety hazards: The start and stop of the production line and the opening and closing of the damper in the corresponding area usually have no automatic interlocking relationship. It may appear that the production line has stopped but the damper has not been closed, resulting in unbalanced distribution of system air volume; or the production line is started without opening the damper, resulting in the accumulation of local exhaust gas. The damper lacks buffering and direct closing may cause pressure surge in the air pipe, impacting the fan.

[0005] Poor system coordination: Fan control and damper control are usually two independent links, lacking unified scheduling. The entire exhaust system runs uncoordinatedly and cannot achieve overall energy efficiency optimization.

[0006] There are also some fan frequency conversion energy-saving modification schemes in the prior art, but they mainly focus on PID constant pressure or constant flow control of the fan itself, and fail to directly, quickly and logically link the load change (production line operating state) of the production source. Therefore, developing a control system and method that can intelligently sense the production load, automatically cooperatively control the fan and the damper, and balance energy saving and safe and efficient operation has important engineering application value and economic significance. SUMMARY

[0007] Purpose of the Invention: Addressing the shortcomings of existing technologies, this invention aims to solve the technical problems in the control of environmental protection fans in chemical fiber production lines, such as excessive manual intervention, high energy consumption, slow response, poor coordination between fans and dampers, and insufficient safety. It provides an intelligent control system and method that can automatically, accurately, and collaboratively control the fan operating frequency and damper opening and closing based on the actual operating load of the production line.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an intelligent control method for environmental protection fans based on production line load, characterized by comprising the following steps: S1: Real-time acquisition of operating status signals of each production line in the chemical fiber workshop; S2: Based on the number of production lines currently in operation and a preset mapping relationship, determine the target operating frequency for the environmental protection fan; the mapping relationship is as follows: when the number of operating production lines is 1, the corresponding low-speed frequency is... When the number of operating production lines is 2, the corresponding medium-speed frequency is... When the number of operating production lines is greater than or equal to 3, the corresponding high-speed frequency is... ;in, ; S3: Send a frequency control command to the wind turbine inverter to adjust the wind turbine's operating frequency to the target operating frequency; S4: For each production line, when its operating status changes from "stopped" to "running", the solenoid valve of the damper on the corresponding exhaust branch pipe is de-energized, driving the damper to open; S5: For each production line, when its operating status changes from "running" to "stopping", a delay timer is started, and the delay continues until the preset delay time is reached. Then, the corresponding damper solenoid valve is energized, driving the damper to close.

[0009] Furthermore, in step S1, the operating status is determined by collecting the current signal of the main motor of each production line or the start / stop feedback signal of the control cabinet.

[0010] Furthermore, the low-speed frequency Medium frequency High-speed frequency The specific values ​​are determined through on-site commissioning based on the rated parameters of the fan and the required exhaust volume for each speed setting.

[0011] Furthermore, the preset delay time The time limit is 30 seconds, which is used to ensure that residual exhaust gas in the area is fully extracted after the production line stops.

[0012] In a second aspect, the present application provides an intelligent control system for environmental protection fans based on production line load, which is used to implement the above method, and is characterized in that the system comprises: a state detection module, configured to acquire running state signals of each production line in real time; a central control unit, connected with the state detection module, configured to receive the state signals, execute the control logic as described in the first aspect, and generate fan frequency control instructions and damper switch control instructions; a fan driving module, comprising a frequency converter, electrically connected with the central control unit and the environmental protection fan, configured to receive the frequency control instructions and adjust the rotating speed of the fan motor; a damper execution module, comprising a plurality of dampers corresponding to exhaust branch pipes of each production line, an execution mechanism for driving the dampers to act, and solenoid valves for controlling the execution mechanism; the solenoid valves are connected with the central control unit, and configured to receive the damper switch control instructions; a human-computer interaction module, connected with the central control unit, configured to set parameters, display states, and issue alarms.

[0013] Further, the central control unit is a programmable logic controller (PLC) or an industrial computer (IPC).

[0014] Further, the state detection module comprises a current sensor or a digital input (DI) acquisition card.

[0015] Further, the system further comprises an alarm module, when the fan overload, damper action timeout or communication failure are detected, the central control unit issues an audible and visual alarm through the alarm module.

[0016] Compared with the prior art, the intelligent control system and method for environmental protection fans based on production line load provided by the present application have the following remarkable beneficial effects: Remarkable energy saving effect: the present application directly links the fan operating frequency with the number of production lines in operation, and realizes the on-demand air supply mode of "supplying as much power as needed". The energy waste caused by long-term high-speed idling of the fan is avoided. According to actual estimation, the energy saving rate can reach 20%-40% during the non-full load production period.

[0017] Fast response and precise control: the system automatically detects the state changes of the production line, responds in milliseconds and executes the control instructions, completely eliminating the delay caused by manual intervention. Through the preset frequency mapping relationship, the control output is accurate, and the optimal matching of the exhaust volume and the production load is ensured.

[0018] Enhancing system safety and reliability: Strict automatic interlocking between the damper and the production line is achieved, eliminating human error such as forgetting to open or close the damper, and ensuring local environmental safety. The delay design before the damper closes ensures sufficient residue removal as required by the process while avoiding system pressure surges caused by instantaneous damper closure, protecting the fan and pipelines.

[0019] Achieving intelligent linkage and reducing labor intensity: The entire control process is fully automated, eliminating the need for frequent manual operation of fans and dampers, freeing operators from repetitive labor, reducing labor intensity, and also reducing production accidents caused by human error.

[0020] The system boasts a clear architecture and strong scalability: Its modular design and clear logic allow it to easily adapt to production lines of different sizes (e.g., 4 or 5 lines) or different process requirements (e.g., adjusting frequency values ​​or modifying delay times) by modifying the mapping table and delay parameters in the central control unit, demonstrating excellent versatility and scalability. Attached Figure Description

[0021] Figure 1 This is a structural block diagram of an intelligent control system for environmentally friendly fans based on production line load, provided in an embodiment of the present invention.

[0022] Figure 2 This is a flowchart of an intelligent control method for environmental protection fans based on production line load, provided in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram illustrating the mapping relationship between fan frequency and the number of operating production lines in an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the damper control timing in an embodiment of the present invention (taking a production line as an example). Detailed Implementation

[0025] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1: refer to Figure 1 This embodiment provides an intelligent control system for environmentally friendly fans based on production line load. The system includes: a status detection module, a central control unit, a fan drive module, a damper execution module, and a human-machine interaction module.

[0027] The status detection module includes multiple current sensors, each installed in the main motor power supply circuit of each production line (assuming three lines: Line 1, Line 2, and Line 3). The current sensors monitor the motor current in real time and transmit analog signals (4-20mA) or converted digital signals (run / stop) to the central control unit. Alternatively, digital (DI) signals representing the operating status of the production line can be directly obtained from the PLC or control cabinet.

[0028] The central control unit uses a Siemens S7-1200 series PLC. The PLC's analog input (AI) or digital input (DI) modules receive signals from the status detection module. The PLC has a pre-written control program; the core algorithm logic of this program will be discussed below. Figure 2 Detailed explanation. The PLC's digital output (DO) module and analog output (AO) module are used to output damper control commands and fan frequency commands, respectively.

[0029] The fan drive module includes an ABB ACS580 series frequency converter. The converter's analog input terminals receive a 4-20mA frequency command signal (corresponding to 0-50Hz) from the PLCAO module, and its output is connected to the main motor of the environmental protection fan. The fan speed is infinitely adjusted by changing the frequency of the output power supply. The frequency converter itself has overcurrent and overload protection functions.

[0030] The damper actuator module includes three pneumatic butterfly valves (corresponding to three exhaust branch pipes respectively), each equipped with a two-position five-way single-electro-controlled solenoid valve as the actuator. When the corresponding output point of the PLC's DO module outputs a low level (0V), the solenoid valve is de-energized, and compressed air drives the cylinder to open the damper; when the output is high level (24V), the solenoid valve is energized, and the cylinder drives the damper to close.

[0031] The human-machine interface module is a touchscreen (HMI) that communicates with the PLC via Ethernet. The HMI can display the real-time operating status (icons or colors) of the three production lines, the current operating frequency of the fans, the open / closed status of each damper, system alarm information, etc. Operators can set key parameters on the HMI, such as the low-speed frequency setpoint. (e.g., 25Hz), medium-speed frequency setting (e.g., 40Hz), high-speed frequency setting (e.g., 50Hz), damper closing delay time (For example, 30 seconds). These parameters are stored in the PLC's data blocks for the control program to access.

[0032] refer to Figure 2 The control method flow of this embodiment is as follows: Step S100: System initialization. After power-on, the PLC reads the parameters set by the HMI. Initialize all variables and check the communication status of each module.

[0033] Step S110: Real-time status acquisition and judgment. The PLC cyclically scans (scan cycle, e.g., 100ms) the input signals corresponding to each production line. For current signals, the PLC program sets a threshold. (e.g., 10% of the motor's rated current). If the current is being detected... If the condition is met, the production line is determined to be in "running" state, and the internal flag is set. Otherwise, it is judged as a "stopped" state and reset. .

[0034] Step S120: Calculate the number of operating production lines . .

[0035] Step S130: Wind turbine frequency mapping and decision. The PLC determines the target frequency based on the N value through a conditional decision program segment (or a lookup table method). The specific mapping relationship is as follows: Figure 3 As shown: like ,but (25Hz); like ,but (40Hz); like ,but (50Hz).

[0036] This mapping logic ensures a basic linear match between the fan output and the production load.

[0037] Step S140: Output fan frequency command. The PLC outputs a frequency command to the inverter via the AO module. The corresponding analog signal. For example, if 4mA corresponds to 0Hz and 20mA corresponds to 50Hz, then... At that time, a 12mA current signal is output. After receiving the signal, the frequency converter controls the fan motor to smoothly change speed to the target frequency.

[0038] Step S150: Damper coordinated control decision and execution. This step is executed in parallel and cyclically with S110-S140, but the logic is performed independently for each production line.

[0039] Step S151: For the i-th production line, determine its... Does a rising edge transition occur (from 0 to 1)? If yes, proceed to step S152: immediately control the solenoid valve output point of the corresponding damper to reset (output 0V), causing the damper to open. This action requires no delay.

[0040] Step S153: Determine its Did a falling edge transition occur (from 1 to 0)? If yes, proceed to step S154: Start the software delay timer corresponding to this production line. And start timing.

[0041] Step S155: In Continuous monitoring during timing The current value. When the timer value reaches the preset value. At 30 seconds, execute step S156: Set the output point of the solenoid valve corresponding to the damper (output 24V) to close the damper. Simultaneously, reset... For future use.

[0042] The timing of damper control is as follows: Figure 4 As shown, the correspondence between production line operation and shutdown and damper opening and delayed closing is clearly demonstrated.

[0043] Step S160: Fault Diagnosis and Alarm. Throughout the process, the PLC continuously monitors the inverter's fault feedback signal, the feedback signals of each damper limit switch (optional, used to confirm whether the damper has operated to the correct position), and the system communication status. If fan overload, damper operation timeout (e.g., no open signal received within 2 seconds after issuing the open command), or module communication interruption is detected, the PLC triggers an audible and visual alarm via the DO module and displays specific alarm information and handling suggestions on the HMI.

[0044] Step S170: Execute repeatedly. Return to step S110 to begin the detection and control of the next scan cycle, forming a closed-loop control.

[0045] This embodiment, through the coordinated operation of the aforementioned hardware and software, perfectly achieves the invention's objective of automatically, intelligently, and collaboratively controlling fans and dampers based on production line load. The system operates stably, exhibits significant energy-saving effects, and greatly improves the automation level and operational economy of the environmental protection system in the chemical fiber production workshop.

[0046] It should be noted that this embodiment uses three production lines as an example. For a larger number of production lines, it is only necessary to expand the number of input points for status detection and correspondingly increase the calculation range of N and the frequency mapping levels in the PLC program (for example, four or five frequency levels can be set). The core control principle remains exactly the same. Delay time Both the frequency values ​​and the range can be flexibly set via HMI to adapt to the needs of different process scenarios.

[0047] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for intelligent control of environmental protection fans based on production line load, characterized in that, Includes the following steps: S1: Real-time acquisition of operating status signals of each production line in the chemical fiber workshop; S2: Based on the number of production lines currently in operation, determine the target operating frequency corresponding to the environmental protection fan according to a preset mapping relationship; the mapping relationship is as follows: when the number of operating production lines is a first number, it corresponds to a first frequency; when the number of operating production lines is a second number, it corresponds to a second frequency; when the number of operating production lines is a third number, it corresponds to a third frequency; wherein, the first number < the second number < the third number, and the first frequency < the second frequency < the third frequency; S3: Send a frequency control command to the wind turbine inverter to adjust the wind turbine's operating frequency to the target operating frequency; S4: For each production line, when its operating status changes from stopped to running, control the opening of the damper on its corresponding exhaust branch pipe; S5: For each production line, when its operating status changes from running to stopped, a delay timer is started, and after the preset delay time is reached, the corresponding damper is controlled to close.

2. The intelligent control method for environmental protection fans based on production line load according to claim 1, characterized in that, In step S1, the operating status is determined by collecting the current signal of the main motor of each production line or the start / stop feedback signal of the control cabinet.

3. The intelligent control method for environmental protection fans based on production line load according to claim 1, characterized in that, The first quantity is 1, corresponding to a low-speed frequency; the second quantity is 2, corresponding to a medium-speed frequency; and the third quantity is greater than or equal to 3, corresponding to a high-speed frequency.

4. The intelligent control method for environmental protection fans based on production line load according to claim 3, characterized in that, The specific values ​​of the first frequency, the second frequency, and the third frequency are set on-site according to the rated parameters of the fan and the required exhaust volume for each speed.

5. The intelligent control method for environmental protection fans based on production line load according to claim 1, characterized in that, The preset delay time is 30 seconds.

6. An intelligent control system for environmental protection fans based on production line load, used to implement the intelligent control method for environmental protection fans based on production line load as described in any one of claims 1-5, characterized in that, include: The status detection module is used to acquire the operating status signals of each production line in real time; The central control unit, connected to the status detection module, is used to receive status signals, execute the control logic as described in any one of claims 1-5, and generate fan frequency control commands and damper opening and closing control commands; The fan drive module includes a frequency converter, which is electrically connected to the central control unit and the environmental protection fan, and is used to receive the frequency control command and adjust the fan motor speed; The damper actuation module includes multiple dampers corresponding to the exhaust branch pipes of each production line, an actuator for driving the damper, and a solenoid valve for controlling the actuator; the solenoid valve is connected to the central control unit and is used to receive the damper opening and closing control command.

7. The intelligent control system for environmentally friendly fans based on production line load according to claim 6, characterized in that, It also includes a human-computer interaction module, which is connected to the central control unit and is used to set parameters of the first frequency, the second frequency, the third frequency and the delay time, and to display the system status.

8. The intelligent control system for environmental protection fans based on production line load according to claim 6, characterized in that, The central control unit is a programmable logic controller (PLC) or an industrial computer (IPC).

9. The intelligent control system for environmentally friendly fans based on production line load according to claim 6, characterized in that, The status detection module includes a current sensor for detecting the current of the main motor of the production line, or a digital input module for collecting the start-stop feedback signal of the production line.

10. The intelligent control system for environmentally friendly fans based on production line load according to claim 6, characterized in that, It also includes an alarm module for issuing an alarm when the fan or damper control malfunctions.

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