Energy-saving tunnel fan with energy recovery function and operation method of fan

Abstract

The invention relates to an energy-saving tunnel fan with an energy recovery function and an operation method, and belongs to the technical field of axial flow fans. The fan comprises a cylindrical shell with two open ends and fan blades coaxially rotating in the shell, a bearing seat is fixed in the shell, and a first rotating shaft of the fan blades is connected with a bearing in an inserted mode and sleeved with a middle wheel set. A fan motor and a generator are fixed outside the shell, a driving wheel of the fan motor and a driven wheel of the generator are connected with the middle wheel set through a first synchronous belt and a second synchronous belt respectively, and the meshing regulation and control module controls the two synchronous belts to be tensioned or loosened; the generator is electrically connected with the energy storage device, and outputs direct current which is stored to the energy storage device through the rectification filtering module and the electric quantity transmitter. The generator serves as a fan speed reduction load, synchronous power generation is achieved during speed reduction, energy recovery is achieved, and energy consumption is effectively reduced.

Description

Technical Field

[0001] This application belongs to the field of axial flow fan technology, specifically relating to an energy-saving tunnel fan with energy recovery function and a method for operating the fan. Background Technology

[0002] Tunnel ventilation fans are the core equipment of highway tunnel ventilation systems. Their main function is to exhaust vehicle exhaust fumes and replenish fresh air, ensuring driving safety and passenger comfort. Existing tunnel ventilation fans are driven by a single motor, mostly a fixed-speed motor. Regardless of changes in vehicle density or airflow demand within the tunnel, the fans operate at full load and rated speed, resulting in significant energy waste during periods of low traffic volume and low airflow demand. Furthermore, when the fans decelerate, they rely solely on mechanical friction braking to dissipate excess kinetic energy, which is then lost as heat during braking, making energy recovery impossible and further exacerbating energy loss. Summary of the Invention

[0003] The technical problem to be solved by this application is to overcome the shortcomings of the prior art and provide an energy-saving tunnel fan with energy recovery function and a method for operating the fan. This application adds a generator, which serves as a load for slowing down the fan. At the same time, the fan can generate electricity while slowing down, thereby realizing energy recovery and reducing energy consumption.

[0004] The technical solution adopted in this application to solve the problems existing in the prior art is: An energy-saving tunnel ventilation fan with energy recovery function includes a cylindrical shell with open ends and fan blades coaxially rotatably connected inside the shell.

[0005] At least two bearing seats are fixed at intervals along the axial direction inside the housing. The first rotating shaft of the fan blade is inserted into the bearing inside the bearing seat. An intermediate wheel set is sleeved on the first rotating shaft. A fan motor and a generator are fixed to the outside of the housing. The output end of the fan motor is provided with a drive wheel. The drive wheel is connected to a pulley of the intermediate pulley group through a first synchronous belt. The generator is equipped with a driven pulley at its output end, and the driven pulley is connected to a pulley of the intermediate pulley group via a second synchronous belt. Both the first and second synchronous belts are connected to the meshing control module, which controls the tension and relaxation of the first and second synchronous belts. The generator is electrically connected to the energy storage device. The DC power output by the generator is input into the energy storage device through the rectifier and filter module and the power transmitter.

[0006] Furthermore, the engagement control module includes a frame, a tension wheel, a tension adjustment device, an electric telescopic rod, and a lever; The frame includes four sliding grooves, which are arranged in pairs at intervals and parallel to each other. The four sliding grooves are fixedly connected by a connecting plate, and a shell fixing plate is fixed to the end of the connecting plate. Two tensioning wheels are provided between two slides in the same group. A second rotating shaft is passed through the middle of the tensioning wheels. Slider blocks are fixed at both ends of the second rotating shaft. The two sliders are slidably disposed inside the two slides in the same group. Two tensioning pulleys between two slides in one set abut against the inner wall of the first synchronous belt, and two tensioning pulleys between two slides in the other set abut against the inner wall of the second synchronous belt. The slide has openings at both the top and bottom ends, and two springs are installed inside the slide, with the two springs respectively located at the opposite ends of the two sliders.

[0007] Furthermore, the tension adjustment device includes a connecting rod arranged parallel to the second rotating shaft, with two block-shaped bodies spaced apart on the connecting rod, and the two block-shaped bodies being arranged corresponding to two sliding grooves in the same group; The block-shaped body includes a limiting block, an inclined outward pushing block, and a top block connected in sequence. The width of the three blocks is the same as or less than the width of the slot, and the length of the top block is greater than the length of the limiting block. One end of the inclined surface of the outward push block abuts against the end face of the limiting block, and the other end abuts against the end face of the top block.

[0008] Furthermore, a clamping plate and a telescopic rod fixing plate are fixed on the connecting plate, and the end of the clamping plate is provided with a rotating hole; A lever is sandwiched in the middle of the clamping plate, and a third rotating rod is located in the middle of the lever. The third rotating rod is inserted into and rotatably connected to the rotating hole. The lever has a slot that extends along the length of the lever. An electric telescopic rod is fixed on the telescopic rod fixing plate. The telescopic part of the electric telescopic rod is coaxially and fixedly connected to the connecting rod of one of the tension adjustment devices. The connecting rod is provided with a plug rod, which is inserted into the slot and slidably connected.

[0009] Furthermore, it also includes a Pitot static pressure pipe air volume sensor and a high-definition industrial camera. The Pitot static pressure pipe air volume sensor is installed at multiple points at the tunnel entrance and exit and the middle section, while the high-definition industrial camera is installed at the tunnel entrance and exit. The data collected by the Pitot static pressure pipe air volume sensor and the high-definition industrial camera is processed and transmitted to the PLC controller. The PLC controller has a built-in PID adjustment algorithm to realize speed control.

[0010] Furthermore, the PLC controller outputs vehicle density levels based on the collected data, with density levels of 0-50 vehicles / hour, 51-100 vehicles / hour, and >100 vehicles / hour. 0-50 vehicles / hour, with excessive airflow, indicates a low-load operating condition. 51-100 vehicles / hour, with air volume meeting standards, is considered a medium-load operating condition. Vehicle density > 100 vehicles / hour and air volume below the preset lower limit are considered high-load operating conditions; Under high load conditions, the fan operates at its rated speed, and the engagement control module controls the generator to separate from the fan blades; Under medium load conditions, the fan speed drops to 70%-80% of the rated speed, and the meshing control module controls the fan motor to disengage from the fan blades, while the generator connects to the fan blades; Under low load conditions, the fan speed drops to 40%-60% of the rated speed. The engagement control module controls the fan motor to disengage from the fan blades, and the generator to connect to the fan blades.

[0011] Furthermore, the generator is a permanent magnet synchronous generator, and the outer diameter of the intermediate wheel assembly is larger than the outer diameter of the driven wheel.

[0012] Furthermore, the energy storage device includes a lithium iron phosphate battery pack and a supercapacitor.

[0013] An operating method for an energy-saving tunnel ventilation fan with energy recovery function includes the following steps: S01, Device Initialization: Initialize all equipment parameters, connect the energy storage device to an external power source to complete pre-charging to SOC≥20%, and the meshing control module controls the first synchronous belt to be tensioned and the second synchronous belt to be relaxed by default, so that the wind turbine is in standby mode; S02, Data Acquisition and Load Assessment: The Pitot static pressure pipe air volume sensor is activated to collect real-time wind speed and air volume data in the tunnel, and the high-definition industrial camera is activated to count the number of vehicles and their speed and output the vehicle density level. All collected data is transmitted to the PLC controller, which then merges the data to determine the tunnel ventilation load. S03, High-load operation: When the PLC controller determines that the operating condition is high load, the control meshing adjustment module keeps the first synchronous belt tensioned and the second synchronous belt relaxed, so that the fan motor and the fan blades are connected in transmission and the generator and the fan blades are separated. The PLC controller uses a built-in PID control algorithm to control the fan motor to run at the rated speed, driving the fan blades to rotate at full load. S04, Medium-load operation: When the PLC controller determines that the operating condition is medium load, it outputs a speed regulation command to control the fan motor speed to drop to 70%-80% of the rated speed; The engagement control module is triggered to move the tension adjustment device via the electric telescopic rod. The lever linkage loosens the first synchronous belt and tensions the second synchronous belt, causing the fan motor to disengage from the fan blades and the generator to connect to the fan blades. The fan blades drive the generator to rotate by inertia. The generator decelerates and brakes the fan blades through the load, and at the same time converts mechanical energy into electrical energy. The alternating current output from the generator is converted into stable direct current by a rectifier and filter module, and then transmitted to the energy storage device after being regulated and filtered by a high-precision DC transmitter. The BMS battery management system monitors the charging process. S05, Low-load operation: When the PLC controller determines that the operating condition is low load, it outputs a speed regulation command to control the fan motor speed to drop to 40%-60% of the rated speed; The engagement control module is triggered to move the tension adjustment device via the electric telescopic rod. The lever linkage loosens the first synchronous belt and tensions the second synchronous belt, causing the fan motor to disengage from the fan blades and the generator to connect to the fan blades. The fan blades drive the generator to rotate. The generator decelerates and brakes the fan blades through the load, while generating electricity. The electrical energy is transmitted to the energy storage device for storage through the rectifier and filter module and the power transmitter. S06. Operating Condition Switching and Power Supply Adjustment: When the PLC controller detects a change in operating conditions, if the medium / low load condition is switched to a high load condition, it immediately controls the meshing control module to restore the tension of the first synchronous belt and the relaxation of the second synchronous belt, so that the fan motor switches back to external power supply and runs at the rated speed, while stopping the braking and power generation of the generator. S07. Troubleshooting and Emergency Handling: During operation, if the BMS battery management system detects overcharging, over-discharging, overheating, or overcurrent of the energy storage device, or if the Pitot static pressure pipe air volume sensor, high-definition industrial camera, fan motor, or generator malfunctions, the PLC controller will immediately control the engagement control module to restore the tension of the first synchronous belt and the relaxation of the second synchronous belt, ensuring the transmission connection between the fan motor and the fan blades. Control the energy storage device to stop charging and discharging, and switch the wind turbine to an external power source for continuous power supply; Trigger a fault alarm and record the fault type and time. Restart the equipment after maintenance personnel have inspected and repaired it.

[0014] Furthermore, in step S05, if the fan needs to increase its speed, the power of the energy storage device is used first to drive the fan motor.

[0015] Compared with the prior art, the beneficial effects of this application are as follows: (1) Add a generator. The generator realizes the dual functions of energy recovery and mechanical braking. When the fan blades enter the deceleration process, the load adjustment of the generator is started simultaneously. By changing the load resistance of the generator, the braking torque is adjusted to realize the smooth deceleration of the fan and replace the traditional mechanical braking. The braking torque is dynamically adjusted according to the deceleration range of the fan blades. The braking torque is small in the initial stage of deceleration to avoid sudden braking. It gradually increases in the later stage to ensure that the fan speed is smoothly reduced to the target value.

[0016] (2) The precise switching between the wind turbine motor and the generator is achieved through the meshing control module. When the wind turbine slows down, the inertia of the fan blades drives the generator to rotate, converting excess mechanical energy into electrical energy and storing it in the energy storage device. When the energy storage device is full and the wind turbine is under low load, the external power supply can be cut off to achieve self-powered operation, meeting the wind turbine's operating requirements for 1-3 hours. This not only recovers the kinetic energy wasted by traditional mechanical braking but also reduces the mains power consumption.

[0017] (3) The precise linkage control of the tension / slack of the first / second synchronous belt is achieved through the meshing control module of the frame, tension wheel, and lever linkage. The electric telescopic rod pushes the tension adjustment device, and the tension wheel spacing can be precisely adjusted by the cooperation of the inclined push block and the spring, ensuring that there is no slippage or jamming during the synchronous belt switching process; and the lever linkage design realizes the reverse synchronous switching of the wind turbine motor and the generator, with fast switching response and high reliability.

[0018] (4) Based on the dual-parameter fusion of air volume sensor and high-definition industrial camera, the load condition of the tunnel is judged. The PLC built-in PID adjustment algorithm realizes stepless and precise control of fan speed, with a speed adjustment response time of ≤0.5s, avoiding vibration and impact caused by sudden speed change; and the load judgment covers multiple points of data at the tunnel entrance and exit and the middle section, eliminating single-point monitoring deviation, and ensuring that the fan operation is highly matched with the actual ventilation demand. Attached Figure Description

[0019] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a structural diagram of an energy-saving tunnel ventilation fan with energy recovery function according to this application. Figure 2 This is a partial sectional view of the casing of an energy-saving tunnel ventilation fan with energy recovery function according to this application. Figure 3 This is a structural diagram of the meshing control module and fan blade connection in an energy-saving tunnel fan with energy recovery function according to this application. Figure 4 This is an exploded view of the fan blades. Figure 5 This is the first structural diagram of the meshing control module. Figure 6 This is the second structural diagram of the meshing control module. Figure 7 This is the first cross-sectional view of the meshing control module. Figure 8 This is the second sectional view of the meshing control module. Figure 9 This is a structural diagram of the meshing control module. Figure 10This is a structural diagram of the transmission component in an energy-saving tunnel ventilation fan with energy recovery function according to this application. Figure 11 This is a structural diagram of the linkage component in an energy-saving tunnel ventilation fan with energy recovery function according to this application. Figure 12 This is a connection frame diagram of an energy-saving tunnel fan energy storage and power supply structure with energy recovery function according to this application.

[0021] In the diagram: 1-Housing, 101-Bearing seat, 102-Mounting base, 2-Fan blade, 201-First rotating shaft, 202-Limiting ring, 3-Snap ring, 4-Key, 5-Intermediate pulley set, 501-Keyway, 6-Fan motor, 601-Driving pulley, 7-First synchronous belt, 8-Generator, 801-Driven pulley, 9-Second synchronous belt, 10-Frame, 1001-Slide groove, 1002-Slot, 1003-Connecting plate, 1004- 1005-Clamping plate, 1006-Rotating hole, 1007-Telescopic rod fixing plate, 11-Tensioning wheel, 12-Second rotating shaft, 1201-Slider, 13-Tension adjustment device, 1301-Connecting rod, 1302-Insertion rod, 1303-Limiting block, 1304-Inclined outward push block, 1305-Top block, 14-Electric telescopic rod, 15-Lever, 1501-Third rotating rod, 1502-Slot, 16-Spring. Detailed Implementation

[0022] The accompanying drawings provide a more detailed description of an energy-saving tunnel ventilation fan with energy recovery function and its operation method, but this is not intended to limit the scope of this application.

[0023] An energy-saving tunnel ventilation fan with energy recovery function includes a cylindrical shell 1 with open ends and fan blades 2 coaxially rotatably connected inside the shell 1.

[0024] The outer side of the housing 1 is provided with a mounting base 102, and the fan body module is fixedly connected to the tunnel roof through the mounting base 102. Inside the housing 1, at least two bearing seats 101 are fixedly fixed at intervals along its axial direction. Bearings are snapped into the bearing seats 101, and the first rotating shaft 201 of the fan blade 2 is inserted into the bearing inside the bearing seat 101.

[0025] To facilitate the installation of the first rotating shaft 201 and to position the fan blade 2 to prevent it from shifting, a limiting ring 202 is fitted onto the first rotating shaft 201 and fixedly connected thereto. An annular groove is recessed on the circular shaft surface of the first rotating shaft 201, and a retaining ring 3 is engaged inside the annular groove. The retaining ring 3 and the limiting ring 202 respectively abut against the two opposite end faces of the end bearing seat 101.

[0026] The fan 1 is externally fixed with a fan motor 6 and a generator 8. An intermediate pulley set 5 is fitted onto the first rotating shaft 201. The intermediate pulley set 5 includes two coaxially arranged pulleys. For easy installation, a keyway 501 is recessed in the inner wall of the intermediate pulley set 5. A key 4 is embedded in the circumference of the first rotating shaft 201. The key 4 is inserted into the keyway 501, so that the intermediate pulley set 5 and the first rotating shaft 201 are fixedly connected.

[0027] The output end of the wind turbine motor 6 is provided with a drive pulley 601, which is connected to a pulley of the intermediate pulley group 5 via a first synchronous belt 7. The output end of the generator 8 is provided with a driven pulley 801, which is connected to a pulley of the intermediate pulley group 5 via a second synchronous belt 9.

[0028] Both the first synchronous belt 7 and the second synchronous belt 9 are connected to the meshing control module. The meshing control module controls the tension and relaxation of the first synchronous belt 7 and the second synchronous belt 9, thereby adjusting the connection status between the fan motor 6 and the generator 8 and the fan blade 2.

[0029] The engagement control module includes a frame 10, a tensioning wheel 11, a tension adjustment device 13, an electric telescopic rod 14, and a lever 15.

[0030] The frame 10 includes four sliding grooves 101, which are arranged in pairs at intervals and parallel to each other. The four sliding grooves 101 are connected by a connecting plate 1003. A housing fixing plate 1004 is fixed to the end of the connecting plate 1003. The housing fixing plate 1004 is an arc-shaped plate, which facilitates tight fixing to the inner wall of the housing 1. The two can be detachably connected by bolts, or they can be fixed by welding after installation.

[0031] Two tensioning wheels 11 are provided between two slide grooves 101 in the same group. A second rotating shaft 12 is coaxially rotatably connected through the middle of the tensioning wheel 11. Slider 1201 is fixed at both ends of the second rotating shaft 12. The two sliders 1201 are respectively slidably disposed inside the two slide grooves 101 in the same group, so that two sliders 1201 slide inside such a slide groove 101.

[0032] Two tensioning rollers 11 between two sets of two slide grooves 101 abut against the inner wall of the first synchronous belt 7, and two tensioning rollers 11 between two sets of two slide grooves 101 abut against the inner wall of the second synchronous belt 9.

[0033] The slide 1001 has slots 1002 at both the upper and lower ends for the second rotating shaft 12 to pass through and slide.

[0034] The slide groove 101 is equipped with two springs 16, which are respectively located at opposite ends of the two sliders 1201. The thrust of the springs 16 causes the two sliders 1201 to drive the two tension wheels 11 to move towards each other and move toward the center.

[0035] The tension adjustment device 13 includes a connecting rod 1301 arranged parallel to the second rotating shaft 12. Two block-shaped bodies are spaced apart on the connecting rod 1301, corresponding to two sliding grooves 1001 in the same group. Each block-shaped body includes a limiting block 1303, an inclined outward pushing block 1304, and a top block 1305 connected in sequence. The width of each block is the same as or 2-4 mm less than the width of the groove 1002. The length of the top block 1305 is greater than the length of the limiting block 1303. One end of the inclined surface of the inclined outward pushing block 1304 abuts against the end face of the limiting block 1303, and the other end abuts against the end face of the fixed block 1305.

[0036] During use, the distance between the two tensioning pulleys 11 in the same group is changed by pushing and pulling the tension adjustment device 13, thereby changing the tension and slack of the synchronous belt. For example, when the limit block 1303 is located inside the slide groove 1001, due to its short length, the slider 1201 slides inward under the push of the spring 16, thereby causing the tensioning pulley 11 to disengage from the synchronous belt, making the synchronous belt slack and unable to perform the transmission function.

[0037] When the tension adjustment device 13 is moved and pulled, the slider 1201 is pushed outward by the inclined surface of the inclined push block 1304, increasing the gap between the two tensioning wheels 11. When the top block 1305 moves into the slide groove 1001, the slider 1201 compresses the spring 16 to move to the outermost position, and the tensioning wheel 11 pushes the synchronous belt outward, thus tensioning the synchronous belt and achieving the transmission function.

[0038] Furthermore, by changing the positions of the two push-pull tension adjustment devices 13, the connection status between the fan motor 6 and the generator 8 and the first rotating shaft 201 of the fan blade 2 can be adjusted.

[0039] To enable the linkage between the two, a clamping plate 1005 and a telescopic rod fixing plate 1007 are fixed on the connecting plate 1003, and a rotating hole 1006 is provided at the end of the clamping plate 1005.

[0040] A lever 15 is sandwiched in the middle of the clamping plate 1005. A third rotating rod 1501 is provided in the middle of the lever 15. The third rotating rod 1501 is inserted into and rotatably connected to the rotating hole 1006. A slot 1502 is provided on the lever 15, which extends along the length of the lever 15.

[0041] An electric telescopic rod 14 is fixed on the telescopic rod fixing plate 1007. The telescopic part of the electric telescopic rod 14 is coaxially and fixedly connected to the connecting rod 1301 of one of the tension adjustment devices. The connecting rod 1301 is provided with a plug rod 1302, which is inserted into and slidably connected to the slot 1502.

[0042] Thus, when the electric telescopic rod 14 pushes the connecting rod 1301 to move, the other connecting rod 1301 moves in the opposite direction under the action of the lever 15.

[0043] Generator 8 is electrically connected to the energy storage device. When the fan motor 6 is connected to the fan blade 2, it drives the fan blade 2 to rotate, thus ventilating the tunnel. When it is necessary to reduce the speed of the fan blade 2, the fan motor 6 is disconnected from the fan blade 2, and the generator 8 is connected to the fan blade 2, which serves to reduce the load speed. At the same time, the fan blade 2 drives the generator 8 to rotate, and the generator 8 generates electricity, which is stored in the energy storage device. The electrical energy stored in the energy storage device serves as a supplementary power source to power the electrical equipment inside the tunnel.

[0044] The speed control trigger logic for fan motor 6 is controlled collaboratively by airflow sensing and vehicle quantity sensing, specifically as follows: Air volume sensing: Pitot static pressure tube air volume sensors are selected and installed at multiple points at the tunnel entrances and exits and the middle section to collect real-time air speed and air volume data in the tunnel, eliminating single-point monitoring deviations.

[0045] Vehicle quantity perception: High-definition industrial cameras are installed at the tunnel entrance and exit using video recognition. AI algorithms are used to count the number of vehicles and their speed in real time. After data fusion, the vehicle density level is output, with density levels of 0-50 vehicles / hour, 51-100 vehicles / hour, and >100 vehicles / hour, which serve as the basis for speed adjustment.

[0046] 0-50 vehicles / hour, with excessive airflow, indicates a low-load condition; 51-100 vehicles / hour, with adequate airflow, indicates a medium-load condition; and vehicle density >100 vehicles / hour, with airflow below the preset lower limit, indicates a high-load condition.

[0047] The data collected by the Pitot static pressure pipe air volume sensor and the high-definition industrial camera is processed and transmitted to the PLC controller. The controller has a built-in PID adjustment algorithm to achieve precise closed-loop control of the speed, with a speed adjustment response time of ≤0.5s, avoiding fan vibration and meshing impact caused by sudden speed changes.

[0048] The speed regulation logic is as follows: High-load conditions: The fan operates at its rated speed, and the engagement control module controls the generator 8 to separate from the fan blades 2 to fully meet the ventilation requirements; Medium load condition: When the fan speed drops to 70%-80% of the rated speed, the engagement control module is triggered, the fan motor 6 is disengaged from the fan blade 2, the generator 8 is connected to the fan blade 2, and the fan blade 2 is decelerated through the load of the generator 8, and energy recovery and braking are started. Low load condition: When the fan speed drops to 40%-60% of the rated speed, the engagement control module is triggered, the fan motor 6 is disengaged from the fan blade 2, the generator 8 is connected to the fan blade 2, and the fan blade 2 is decelerated through the load of the generator 8, thus starting energy recovery and braking.

[0049] In order to make the braking effect of generator 8 smoother, in this embodiment, generator 8 adopts permanent magnet synchronous generator. This type of generator has high power generation efficiency, small size, and low starting torque. In addition, the outer diameter of intermediate wheel set 5 is larger than the outer diameter of passive wheel 8, which can also play a speed-increasing role and further improve power generation efficiency.

[0050] The energy storage device is electrically connected to the generator 8 through a rectifier and filter module. The rectifier and filter module converts the AC power output by the generator into stable DC power with a filtering accuracy of ≤5%, thus avoiding damage to the energy storage device due to voltage fluctuations.

[0051] The energy storage device includes lithium iron phosphate battery packs and supercapacitors, balancing energy storage capacity and charging / discharging speed to adapt to the intermittent nature of energy recovery and the rapid switching of power supply. The supercapacitor serves as an auxiliary energy storage component, with a fast charging / discharging speed. It can quickly absorb the electrical energy recovered by the generator and rapidly release electrical energy during power supply switching, compensating for the shortcomings of lithium battery charging / discharging delays and improving switching stability.

[0052] Capacity calculation of lithium iron phosphate battery packs and supercapacitors: Taking a 55kW wind turbine that can operate for 1-3 hours as an example, with a rated power consumption of 55kWh / h and a safety factor of 1.2, the total energy storage capacity needs to reach 66-198kWh; of which the lithium battery pack accounts for 90%, with a capacity of 59.4-178.2kWh, and the supercapacitor accounts for 10%, with a capacity of 6.6-19.8kWh.

[0053] The DC power output from generator 8 is input and stored in the energy storage device through a rectifier and filter module and a power transmitter. In order to better match the deceleration and energy recovery of the tunnel fan, a high-precision DC transmitter with an accuracy of ±0.5% is selected in this embodiment to monitor the voltage, current and power output of the generator in real time. At the same time, the power is stabilized and filtered to output a stable voltage to the energy storage device to avoid voltage fluctuations damaging the battery.

[0054] The BMS (Battery Management System) monitors the energy storage device's state of charge (SOC), voltage, temperature, and charging / discharging current in real time, providing overcharge, over-discharge, overheat, and overcurrent protection. When the SOC is ≥ 95%, charging is stopped, and the generator is controlled to reduce its load and braking torque. When the SOC is ≤ 20%, an external power supply is triggered to prevent the battery from running out of power.

[0055] The transmission line uses copper core cables, with the cross-sectional area selected according to the current to reduce line loss. A surge protection module is installed between the transmitter and the energy storage device to prevent damage to the equipment from lightning strikes or voltage surges.

[0056] The energy storage device uses a vacuum contactor as a bidirectional switching switch to achieve seamless switching between the external power supply and the energy storage device. The switching logic is controlled collaboratively by the PLC and BMS.

[0057] When the BMS detects that the SOC is ≥80%, which meets the requirement of 1-3 hours of operation, and the fan is in a low-load condition, the PLC sends a switching signal, the two-way switch disconnects the external power supply, connects the energy storage device to supply power, and the fan runs by the energy storage power supply, realizing self-powered triggering. When SOC≤20% and the wind turbine enters medium-high load operation, the PLC immediately sends a switching signal to switch back to external power supply, and at the same time starts the generator to recover energy and charge the energy storage device. To improve energy efficiency, if the fan speed needs to be increased during the energy storage power supply period, the stored energy will be used to drive the fan first.

[0058] An operating method for an energy-saving tunnel ventilation fan with energy recovery function includes the following steps: S01, Device Initialization Install tunnel fans, air volume sensors, high-definition industrial cameras, and energy storage devices at designated locations in the tunnel. Electrically connect the air volume sensors, high-definition industrial cameras, and energy storage devices to the PLC controller. Initialize all equipment parameters. Connect the energy storage device to an external power source to complete pre-charging to SOC≥20%. By default, the meshing control module controls the first synchronous belt 7 to be tensioned and the second synchronous belt 9 to be relaxed. The fans are in standby mode.

[0059] S02, Data Acquisition and Load Assessment The Pitot static pressure pipe air volume sensor is activated to collect real-time wind speed and air volume data inside the tunnel. A high-definition industrial camera is activated to use AI algorithms to count the number and speed of vehicles, outputting a vehicle density level. All collected data is transmitted to the PLC controller, which then integrates the data to determine the tunnel ventilation load condition. S03, High-load operation When the PLC controller determines that the operating condition is high load, it performs the following operations: S031, The control meshing adjustment module keeps the first synchronous belt 7 tensile and the second synchronous belt 9 slack, the fan motor 6 and the fan blade 2 are connected in transmission, and the generator 8 is separated from the fan blade 2; S032, the PLC's built-in PID control algorithm controls the fan motor 6 to run at the rated speed, driving the fan blades 2 to rotate at full load to meet the tunnel ventilation requirements; S033. The energy storage device is kept connected to the external power source. The BMS battery management system monitors the SOC in real time. If the SOC is ≤20%, it is charged by the external power source. If the SOC is ≥95%, charging is stopped.

[0060] S04, Medium-load operation When the PLC controller determines that the operating condition is medium load, it performs the following operations: S041, PLC outputs speed regulation command to control the speed of fan motor 6 to drop to 70%-80% of the rated speed, with a speed regulation response time ≤0.5s; S042, Trigger the engagement control module to move, the electric telescopic rod 14 pushes the tension adjustment device 13 to move, and through the lever 15, the first synchronous belt 7 is relaxed and the second synchronous belt 9 is tensioned; S043, the fan blade 2 drives the generator 8 to rotate by inertia, and the generator 8 decelerates and brakes the fan blade 2 through the load, while converting mechanical energy into electrical energy. S044. The AC power output by generator 8 is converted into stable DC power by the rectifier and filter module, and then transmitted to the energy storage device after being regulated and filtered by the high-precision DC transmitter. The BMS system monitors the charging process and collects parameters such as SOC, voltage, and temperature in real time. When SOC ≥ 95%, the system controls generator 8 to reduce the load, reduce the braking torque, and stop charging the energy storage device. S045. The energy storage device shall be kept connected to the external power source. If the SOC is less than or equal to 20%, the device shall be switched to the external power source to ensure the operation of the wind turbine motor 6.

[0061] S05, Low-load operation When the PLC controller determines that the operating condition is low load, perform the following operations: S051, PLC outputs speed regulation command to control the speed of fan motor 6 to be reduced to 40%-60% of the rated speed, with a speed regulation response time ≤0.5s; S052, Trigger the engagement control module to move, the electric telescopic rod 14 pushes the tension adjustment device 13 to move, and through the lever 15 linkage, the first synchronous belt 7 is relaxed and the second synchronous belt 9 is tensioned, the fan motor 6 is disengaged from the fan blade 2, and the generator 8 is connected to the fan blade 2. S053, the fan blade 2 drives the generator 8 to rotate, the generator 8 brakes the fan blade 2 through the load deceleration, and generates electricity at the same time. The electrical energy is transmitted to the energy storage device for storage through the rectifier and filter module and the power transmitter. The BMS system monitors the charging process according to the S044 rule. S054. The BMS system monitors the SOC of the energy storage device in real time. When the SOC is ≥ 80% and the fan is continuously under low load, the PLC sends a switching signal to control the vacuum contactor to disconnect the external power supply and connect the energy storage device to supply power to the fan motor 6, so as to realize the self-powered operation of the fan. S055. If the fan needs to increase its speed, the power of the energy storage device should be used to drive the fan first.

[0062] S06, Operating Condition Switching and Power Supply Adjustment When the PLC controller detects a change in operating condition, it performs the following operations: S061, when switching from medium / low load to high load, the PLC immediately controls the meshing control module to restore the tension of the first synchronous belt 7 and the relaxation of the second synchronous belt 9. The fan motor 6 switches back to external power supply and runs at the rated speed. At the same time, the braking and power generation of the generator 8 are stopped. S062. When SOC ≤ 20% under self-powered state, the PLC immediately controls the bidirectional switching switch to switch back to external power supply.

[0063] S07. Troubleshooting and Emergency Handling During operation, if the BMS system detects overcharging, over-discharging, overheating, or overcurrent in the energy storage device, or if a sensor / camera / motor / generator malfunctions, the PLC controller will immediately execute the following: S071, The meshing control module restores the tension of the first synchronous belt 7 and the relaxation of the second synchronous belt 9 to ensure the transmission connection between the fan motor 6 and the fan blade 2; S072, The energy storage device stops charging and discharging, and the fan switches to an external power source for continuous power supply; S073. Trigger a fault alarm, record the fault type and time, and restart the equipment after maintenance personnel have inspected and repaired it.

[0064] S08, Routine Operation and Energy Management The S02-S07 steps are continuously executed in a loop. The BMS system optimizes the charging and discharging strategy of the energy storage device in real time. Copper core cables are used in the transmission lines to reduce losses. The surge protection module between the transmitter and the energy storage device continuously protects against lightning strikes and voltage surges. The power generation and power saving are regularly counted. The PID speed regulation parameters and load judgment thresholds are optimized according to the changes in tunnel traffic flow and air volume to maximize energy saving.

[0065] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. An energy-saving tunnel ventilation fan with energy recovery function, comprising a cylindrical shell (1) with open ends and fan blades (2) coaxially rotatably connected inside the shell (1), characterized in that... ； At least two bearing seats (101) are fixed at intervals along the axial direction inside the housing (1). The first rotating shaft (201) of the fan blade (2) is inserted into the bearing inside the bearing seat (101). An intermediate wheel set (5) is sleeved on the first rotating shaft (201). The outer casing (1) is fixed with a fan motor (6) and a generator (8). The output end of the fan motor (6) is provided with a drive wheel (601). The drive wheel (601) is connected to a pulley of the intermediate pulley group (5) through a first synchronous belt (7). The output end of the generator (8) is provided with a passive pulley (801), and the passive pulley (801) is connected to a pulley of the intermediate pulley group (5) by a second synchronous belt (9); Both the first synchronous belt (7) and the second synchronous belt (9) are connected to the meshing control module, which controls the tension and relaxation of the first synchronous belt (7) and the second synchronous belt (9). The generator (8) is electrically connected to the energy storage device. The DC power output by the generator (8) is input into the energy storage device through the rectifier filter module and the power transmitter.

2. The energy-saving tunnel ventilation fan with energy recovery function according to claim 1, characterized in that: The engagement control module includes a frame (10), a tension wheel (11), a tension adjustment device (13), an electric telescopic rod (14), and a lever (15). The frame (10) includes four slides (101), which are arranged in pairs in parallel. The four slides (101) are fixedly connected by a connecting plate (1003), and a shell fixing plate (1004) is fixed at the end of the connecting plate (1003). Two tensioning wheels (11) are provided between the two slides (101) in the same group. A second rotating shaft (12) is passed through the middle of the tensioning wheel (11). Slider (1201) is fixed at both ends of the second rotating shaft (12). The two sliders (1201) are respectively slidably disposed inside the two slides (101) in the same group. Two tensioning rollers (11) between two slides (101) in one set abut against the inner wall of the first synchronous belt (7), and two tensioning rollers (11) between two slides (101) in another set abut against the inner wall of the second synchronous belt (9); The slide (1001) has slots (1002) at both the top and bottom ends. The slide (101) has two springs (16) inside, and the two springs (16) are respectively set at the opposite ends of the two sliders (1201).

3. The energy-saving tunnel ventilation fan with energy recovery function according to claim 2, characterized in that: The tension adjustment device (13) includes a connecting rod (1301) arranged parallel to the second rotating shaft (12). Two block-shaped bodies are spaced apart on the connecting rod (1301), and the two block-shaped bodies are arranged corresponding to two sliding grooves (1001) in the same group. The block includes a limiting block (1303), an inclined push block (1304), and a top block (1305) connected in sequence. The width of the three blocks is the same as or less than the width of the slot (1002). The length of the top block (1305) is greater than the length of the limiting block (1303). One end of the inclined surface of the inclined push block (1304) abuts against the end face of the limiting block (1303), and the other end abuts against the end face of the top block (1305).

4. The energy-saving tunnel ventilation fan with energy recovery function according to claim 2, characterized in that: The connecting plate (1003) is fixed with a clamping plate (1005) and a telescopic rod fixing plate (1007), and the end of the clamping plate (1005) is provided with a rotating hole (1006). A lever (15) is sandwiched in the middle of the clamping plate (1005). A third rotating rod (1501) is provided in the middle of the lever (15). The third rotating rod (1501) is inserted into and rotatably connected to the rotating hole (1006). A slot (1502) is provided on the lever (15) extending along the length of the lever (15). An electric telescopic rod (14) is fixed on the telescopic rod fixing plate (1007). The telescopic part of the electric telescopic rod (14) is coaxially fixedly connected to the connecting rod (1301) of one of the tension adjustment devices (13). The connecting rod (1301) is provided with a plug rod (1302). The plug rod (1302) is inserted into and slidably connected to the slot (1502).

5. The energy-saving tunnel ventilation fan with energy recovery function according to claim 1, characterized in that: It also includes a Pitot static pressure tube air volume sensor and a high-definition industrial camera. The Pitot static pressure tube air volume sensor is installed at multiple points at the tunnel entrance and exit and the middle section, while the high-definition industrial camera is installed at the tunnel entrance and exit. The data collected by the Pitot static pressure pipe air volume sensor and the high-definition industrial camera is processed and transmitted to the PLC controller. The PLC controller has a built-in PID adjustment algorithm to realize speed control.

6. The energy-saving tunnel ventilation fan with energy recovery function according to claim 5, characterized in that: The PLC controller outputs vehicle density levels based on the collected data, with density levels of 0-50 vehicles / hour, 51-100 vehicles / hour, and >100 vehicles / hour. 0-50 vehicles / hour, with excessive airflow, indicates a low-load operating condition. 51-100 vehicles / hour, with air volume meeting standards, constitutes a medium-load operating condition. A vehicle density greater than 100 vehicles / hour and an air volume lower than the preset lower limit constitute a high-load operating condition. Under high load conditions, the fan runs at its rated speed, and the meshing control module controls the generator (8) to separate from the fan blades (2); Under medium load conditions, the fan speed drops to 70%-80% of the rated speed. The meshing control module controls the fan motor (6) to disengage from the fan blade (2), and the generator (8) to connect with the fan blade (2). Under low load conditions, the fan speed drops to 40%-60% of the rated speed. The meshing control module controls the fan motor (6) to disengage from the fan blade (2), and the generator (8) connects to the fan blade (2).

7. The energy-saving tunnel ventilation fan with energy recovery function according to claim 1, characterized in that: The generator (8) is a permanent magnet synchronous generator, and the outer diameter of the intermediate wheel assembly (5) is larger than the outer diameter of the passive wheel (8).

8. The energy-saving tunnel ventilation fan with energy recovery function according to claim 1, characterized in that: The energy storage device includes a lithium iron phosphate battery pack and a supercapacitor.

9. A method for operating an energy-saving tunnel ventilation fan with energy recovery function, characterized in that, Includes the following steps: S01, Device Initialization: Initialize all equipment parameters, connect the energy storage device to an external power source to complete pre-charging to SOC≥20%, and the meshing control module controls the first synchronous belt (7) to be tensioned and the second synchronous belt (9) to be relaxed by default, so that the wind turbine is in standby mode; S02, Data Acquisition and Load Assessment: The Pitot static pressure pipe air volume sensor is activated to collect real-time wind speed and air volume data in the tunnel, and the high-definition industrial camera is activated to count the number of vehicles and their speed and output the vehicle density level. All collected data is transmitted to the PLC controller, which then merges the data to determine the tunnel ventilation load condition. S03, High-load operation: When the PLC controller determines that the operating condition is high load, the control engagement adjustment module keeps the first synchronous belt (7) taut and the second synchronous belt (9) slack, so that the fan motor (6) and the fan blade (2) are connected in transmission and the generator (8) and the fan blade (2) are separated. The PLC controller uses a built-in PID control algorithm to control the fan motor (6) to run at the rated speed, driving the fan blades (2) to rotate at full load. S04, Medium-load operation: When the PLC controller determines that the operating condition is medium load, it outputs a speed regulation command to control the speed of the fan motor (6) to drop to 70%-80% of the rated speed; Trigger the engagement control module to move the tension adjustment device (13) by pushing the electric telescopic rod (14), and achieve the first synchronous belt (7) to loosen and the second synchronous belt (9) to tighten by lever (15), so that the fan motor (6) is disengaged from the fan blade (2) and the generator (8) is connected to the fan blade (2). The fan blade (2) drives the generator (8) to rotate by inertia. The generator (8) decelerates and brakes the fan blade (2) through the load, and at the same time converts mechanical energy into electrical energy. The AC power output by the generator (8) is converted into stable DC power by the rectifier and filter module, and then transmitted to the energy storage device after being regulated and filtered by the high-precision DC transmitter. The BMS battery management system monitors the charging process. S05, Low-load operation: When the PLC controller determines that the operating condition is low load, it outputs a speed regulation command to control the speed of the fan motor (6) to drop to 40%-60% of the rated speed; Trigger the engagement control module to move the tension adjustment device (13) by pushing the electric telescopic rod (14), and achieve the first synchronous belt (7) to loosen and the second synchronous belt (9) to tighten by lever (15), so that the fan motor (6) is disengaged from the fan blade (2) and the generator (8) is connected to the fan blade (2). The fan blade (2) drives the generator (8) to rotate. The generator (8) brakes the fan blade (2) by decelerating the load and generates electricity at the same time. The electrical energy is transmitted to the energy storage device for storage through the rectifier and filter module and the power transmitter. S06. Operating Condition Switching and Power Supply Adjustment: When the PLC controller detects the change of operating conditions, if the medium / low load operating condition is switched to the high load operating condition, it immediately controls the meshing control module to restore the tension of the first synchronous belt (7) and the relaxation of the second synchronous belt (9), so that the fan motor (6) switches back to external power supply and runs at the rated speed, and at the same time stops the braking and power generation of the generator (8). S07. Troubleshooting and Emergency Handling: During operation, if the BMS battery management system detects overcharging, over-discharging, overheating, or overcurrent of the energy storage device, or if the Pitot static pressure pipe air volume sensor, high-definition industrial camera, fan motor (6), or generator (8) malfunctions, the PLC controller will immediately control the meshing control module to restore the tension of the first synchronous belt (7) and the relaxation of the second synchronous belt (9) to ensure the transmission connection between the fan motor (6) and the fan blade (2). Control the energy storage device to stop charging and discharging, and switch the wind turbine to an external power source for continuous power supply; Trigger a fault alarm and record the fault type and time. Restart the equipment after maintenance personnel have inspected and repaired it.

10. The operating method of the energy-saving tunnel ventilation fan with energy recovery function according to claim 9, characterized in that: If the fan needs to increase its speed in S05, the power of the energy storage device will be used first to drive the fan motor (6).

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