Efficient hydrogen discharging and ventilating method utilizing downward-pumping upward-feeding directional airflow

Abstract

The invention discloses an efficient hydrogen discharging and ventilating method utilizing downward-pumping upward-feeding directional airflow. According to a traditional scheme, a top single-side main air pipe is adopted to be matched with an axial flow fan, or a single main air pipe is matched with evenly-distributed branch pipes, hydrogen is low in density and prone to being accumulated at the top, and a traditional side wall is low in even exhaust efficiency. The system comprises a main air pipeline, a branch pipeline, a vertical air pipe, a ventilation unit and a central controller, wherein the main air pipeline comprises a lower air draft main pipe and an upper air supply main pipe; the branch pipeline is connected with the lower air draft main pipe; the vertical air pipes are uniformly distributed at the tail ends of the branch pipelines; the ventilation unit is communicated with the upper air supply main pipe and arranged on the outer wall side of the storage battery chamber, and the ventilation unit comprises a main anti-explosion axial flow fan and a standby emergency hydrogen discharging fan. The device is used for efficient hydrogen discharge and ventilation of the storage battery chamber of the thermal power plant.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal power plant safety facilities, in particular to an improved pipeline arrangement structure for a battery room ventilation system, which is suitable for closed spaces with risks of hydrogen and acid mist accumulation. BACKGROUND

[0002] The battery room of a thermal power plant releases hydrogen and acid mist during charging and discharging. High hydrogen concentration can easily cause explosions, and acid mist can corrode equipment. Therefore, continuous ventilation is required to exhaust hydrogen (lower explosive limit 4%) and acid mist. Traditional solutions mostly use a top single-sided main air pipe with an axial flow fan, or a single main air pipe with evenly distributed branch pipes, but have the following problems: 1. Hydrogen stratification effect is not utilized: hydrogen is low in density and easily accumulates at the top, and the traditional side wall uniform exhaust efficiency is low; 2. Local dead angle ventilation is insufficient: fixed branch pipe spacing leads to uneven airflow distribution, and corner areas are prone to gas retention; 3. High energy consumption: the fan needs to be continuously operated at high power to cover the risk area; 4. Maintenance difficulty: complex pipeline arrangement and inconvenient installation of detection sensors. SUMMARY

[0003] The purpose of the present application is to solve the technical problems in the background art and provide a high-efficiency hydrogen exhaust ventilation method using downward suction and upward blowing directional airflow.

[0004] The above-mentioned purpose is achieved by the following solution: A high-efficiency hydrogen exhaust ventilation method using downward suction and upward blowing directional airflow, the method comprising the following steps: (1) The system defaults to start the explosion-proof axial flow ventilation fan, and the PLC compares the real-time measurement value of the hydrogen concentration sensor with the set value, such as hydrogen concentration volume ratio 0.5%, and automatically outputs a 4-20mA signal to the frequency converter through PID operation to smoothly adjust the fan speed, realizing on-demand ventilation; (2) When the reading of any hydrogen concentration sensor exceeds the first safety threshold, such as 1%, the PLC immediately issues an instruction to start the emergency hydrogen exhaust fan and runs at full speed, at this time, the two fans work simultaneously to achieve maximum exhaust capacity; (3) The vertical wind pipe and branch pipe extract air from the top of the battery room and supply air to the outside of the battery room through the main air pipe; (4) The lower air extraction main pipe and the upper air supply main pipe form a downward suction and upward blowing airflow organization based on the hydrogen up-floating characteristics to accelerate hydrogen exhaust.

[0005] The aforementioned efficient hydrogen exhaust ventilation method utilizes a downward-extraction and upward-supplying directional airflow. The main air duct includes a lower exhaust main pipe and an upper supply main pipe; branch pipes are connected to the lower exhaust main pipe; vertical air ducts are evenly distributed at the ends of each branch pipe; the ventilation unit is connected to the upper supply main pipe and is installed on the outer wall of the battery room; the ventilation unit includes a main explosion-proof axial flow fan and a backup emergency hydrogen exhaust fan; the central controller is electrically connected to the ventilation unit and is used to receive hydrogen concentration sensor signals and control the operation of the explosion-proof axial flow fan and the emergency hydrogen exhaust fan according to the signals.

[0006] The efficient hydrogen exhaust ventilation method utilizing downward extraction and upward delivery of directional airflow is described above, wherein the main air duct, branch ducts, and vertical air ducts are all made of stainless steel.

[0007] The efficient hydrogen exhaust ventilation method utilizing downward extraction and upward delivery directional airflow, wherein the central controller is a programmable logic controller.

[0008] The aforementioned efficient hydrogen exhaust ventilation method utilizes a downward-drawing and upward-sending directional airflow, wherein the explosion-proof axial flow fan and the emergency hydrogen exhaust fan are connected in parallel. Beneficial effects

[0009] 1. This invention utilizes a directional airflow organization of "downward extraction and upward delivery" to actively extract hydrogen from the source and accelerate its discharge by taking advantage of its upward floating characteristics, effectively preventing the local accumulation of hydrogen at the top and fundamentally eliminating the risk of explosion.

[0010] 2. The system of the present invention automatically adjusts the main fan speed according to the real-time hydrogen concentration to achieve "ventilation on demand", minimizing fan energy consumption under the premise of safety and significantly saving operating costs.

[0011] 3. This invention employs a dual-fan configuration with one fan in operation and one on standby, and includes an automatic emergency response mechanism. When the hydrogen concentration exceeds the standard, the standby fan can be quickly activated to fully discharge hydrogen, providing redundant safety assurance.

[0012] 4. This invention employs a scientific airflow organization to improve ventilation efficiency; the stainless steel material ensures the durability of the pipes in corrosive environments, guaranteeing the long-term stable operation of the system. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an embodiment of this application; Figure 2 This is a schematic diagram of the hydrogen venting port proposed in the embodiments of this application; Figure 3 This is a detailed layout diagram of the battery compartment proposed in the embodiments of this application. Detailed Implementation

[0014] likeFigure 1 , Figure 2 and Figure 3 In this embodiment, a highly efficient hydrogen exhaust ventilation method utilizing a downward-drawing and upward-feeding directional airflow is provided, comprising the following steps: (1) The system defaults to starting the explosion-proof axial flow fan. The PLC compares the real-time measurement value of the hydrogen concentration sensor with the set value, such as the hydrogen concentration volume ratio of 0.5%. Through PID calculation, it automatically outputs a 4-20mA signal to the frequency converter to smoothly adjust the fan speed and realize ventilation on demand. (2) When the reading of any hydrogen concentration sensor exceeds the first safety threshold, such as 1%, the PLC immediately issues a command to start the emergency hydrogen exhaust fan and run it at full speed at the power frequency. At this time, the two fans work at the same time to achieve the maximum exhaust volume. (3) The vertical air duct and branch pipes draw air from the top of the battery room and supply air to the outside of the battery room through the main air duct; (4) The lower exhaust pipe and the upper supply pipe form an airflow organization of downward extraction and upward supply based on the rising characteristics of hydrogen, so as to accelerate the discharge of hydrogen.

[0015] A highly efficient hydrogen exhaust ventilation method utilizing downward-extraction and upward-supply directional airflow includes a main air duct 1, branch ducts 2, vertical ducts 3, a ventilation unit 4, and a central controller 5. The main air duct 1 includes a lower exhaust main duct 11 and an upper supply main duct 12. The branch ducts 2 are connected to the lower exhaust main duct 11. The vertical ducts 3 are evenly distributed at the ends of each branch duct 2. The ventilation unit 4 is connected to the upper supply main duct 12 and is installed on the outer wall side of the battery room. The ventilation unit 4 includes a main explosion-proof axial flow fan 41 and a backup emergency hydrogen exhaust fan 42. The central controller 5 is electrically connected to the ventilation unit 4 and is used to receive hydrogen concentration sensor signals and control the operation of the explosion-proof axial flow fan 41 and the emergency hydrogen exhaust fan 42 according to the signals.

[0016] The main air duct 1, branch air duct 2, and vertical air duct 3 are all made of stainless steel.

[0017] The central controller 5 is a programmable logic controller.

[0018] The explosion-proof axial flow fan 41 and the emergency hydrogen exhaust fan 42 are connected in parallel.

[0019] The vertical air duct 3 and the branch duct 2 draw air from the top of the battery room and send air to the outside of the battery room through the main air duct 1.

[0020] The lower exhaust pipe 11 and the upper air supply pipe 12 form a "lower extraction and upper supply" airflow organization based on the rising characteristics of hydrogen to accelerate the discharge of hydrogen.

[0021] The central controller 5 is configured to: under normal operating conditions, automatically adjust the speed of the explosion-proof axial flow fan 41 according to the hydrogen concentration signal; and control the emergency hydrogen exhaust fan 42 to start when the hydrogen concentration value exceeds the first preset threshold.

[0022] The central controller 5 is also configured to control the explosion-proof axial flow fan 41 and the emergency hydrogen exhaust fan 42 to operate at maximum power simultaneously when the hydrogen concentration value exceeds a second preset threshold higher than the first preset threshold. The vertical air duct 3 and the branch pipe 2 draw air from the top of the battery room and send air to the outside of the battery room through the main air duct 1. The main air duct 1 is made of 304 stainless steel plate, which has excellent corrosion resistance. It includes a lower exhaust duct 11 and an upper air supply duct 12. The lower exhaust duct 11 has a rectangular cross-section, preferably 300mm×400mm, and is centrally located below the ceiling along the length of the battery room. The upper air supply duct 12 includes an air supply vertical pipe 121 and a horizontal air supply pipe 122. The air supply vertical pipe 121 is arranged vertically and connected to the lower exhaust duct 11.

[0023] The branch pipe 2 is also made of stainless steel and extends horizontally from both sides of the lower exhaust main pipe 11. The rectangular cross-sectional dimensions are preferably 200mm × 400mm. The vertical air duct 3 is evenly distributed at the ends of each branch pipe 2. The rectangular cross-sectional dimensions are preferably 200mm × 200mm. It extends vertically upward, and its exhaust port is 100mm to 150mm above the ceiling.

[0024] The ventilation unit 4 is connected to the upper air supply main pipe 12 and is installed on the fan platform reserved on the outer wall of the battery room. The ventilation unit 4 includes two fans connected in parallel: one is an explosion-proof axial flow fan 41, whose air volume can be adjusted by frequency conversion as needed; the other is a backup emergency hydrogen exhaust fan 42, which is a fixed-speed fan with a power and air volume greater than the main fan, and is specially designed for emergency high-flow hydrogen exhaust. Both fans are equipped with check valves at their outlets to prevent airflow short-circuiting.

[0025] The central controller 5 is electrically connected to the ventilation unit 4 and is used to receive hydrogen concentration sensor signals and control the operation of the explosion-proof axial flow fan 41 and the emergency hydrogen exhaust fan 42 according to the signals.

[0026] The central controller 5 is a standard PLC (such as a Siemens S7-1200 series), installed on the outer wall of the battery room. Inside the battery room, eight hydrogen concentration sensors 601 are evenly arranged, positioned directly above the battery rack 602, with their signal lines connected to the PLC's analog input module. The PLC program has the following preset core control logic: Normal operation mode: The system defaults to starting the explosion-proof axial flow fan 41. The PLC compares the real-time measurement value of the hydrogen concentration sensor 601 with the set value (such as hydrogen concentration volume ratio of 0.5%), and automatically outputs a 4-20mA signal to the frequency converter through PID calculation to smoothly adjust the fan speed and achieve ventilation on demand.

[0027] Emergency operation mode: When the reading of any hydrogen concentration sensor 601 exceeds the first safety threshold (e.g., 1%), the PLC immediately issues a command to start the emergency hydrogen exhaust fan 42, which runs at full speed at the power frequency. At this time, both fans work simultaneously to achieve maximum exhaust volume.

[0028] Over-limit alarm mode: If the concentration continues to rise and exceeds the second safety threshold (e.g., 3%), the PLC will not only keep the fan running at full speed, but also trigger an audible and visual alarm.

Claims

1. A highly efficient hydrogen exhaust ventilation method utilizing a downward-drawing and upward-sending directional airflow, characterized by: The method includes the following steps: (1) The system defaults to starting the explosion-proof axial flow fan. The PLC compares the real-time measurement value of the hydrogen concentration sensor with the set value, such as the hydrogen concentration volume ratio of 0.5%. Through PID calculation, it automatically outputs a 4-20mA signal to the frequency converter to smoothly adjust the fan speed and realize ventilation on demand. (2) When the reading of any hydrogen concentration sensor exceeds the first safety threshold, such as 1%, the PLC immediately issues a command to start the emergency hydrogen exhaust fan and run it at full speed at the power frequency. At this time, the two fans work at the same time to achieve the maximum exhaust volume. (3) The vertical air duct and branch pipes draw air from the top of the battery room and supply air to the outside of the battery room through the main air duct; (4) The lower exhaust pipe and the upper supply pipe form an airflow organization of downward extraction and upward supply based on the rising characteristics of hydrogen, so as to accelerate the discharge of hydrogen.

2. The efficient hydrogen exhaust ventilation method using downward extraction and upward delivery directional airflow according to claim 1, characterized in that: The main air duct includes a lower exhaust duct and an upper supply duct; the branch ducts are connected to the lower exhaust duct; the vertical ducts are evenly distributed at the ends of each branch duct; the ventilation unit is connected to the upper supply duct and is installed on the outer wall of the battery room; the ventilation unit includes a main explosion-proof axial flow fan and a backup emergency hydrogen exhaust fan; the central controller is electrically connected to the ventilation unit and is used to receive hydrogen concentration sensor signals and control the operation of the explosion-proof axial flow fan and the emergency hydrogen exhaust fan according to the signals.

3. The efficient hydrogen exhaust ventilation method using a downward-drawing and upward-feeding directional airflow according to claim 2, characterized in that: The main air duct, branch ducts, and vertical air ducts are all made of stainless steel.

4. The efficient hydrogen exhaust ventilation method using downward extraction and upward delivery directional airflow according to claim 3, characterized in that: The central controller is a programmable logic controller.

5. The efficient hydrogen exhaust ventilation method using a downward-drawing and upward-feeding directional airflow according to claim 4, characterized in that: The explosion-proof axial flow fan and the emergency hydrogen exhaust fan are connected in parallel.

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