A low coal dust leakage amount ventilation system for a strip coal yard

Abstract

The utility model provides a strip coal yard low coal dust leakage amount ventilation system, including ventilation valve plate module, spray dust suppression module, monitoring and control system, inlet louver, ventilation valve plate module includes a plurality of independent control units along the length direction of strip coal yard is provided, and each independent control unit adopts the shed roof structure of double slope type, and the arc cross section of double slope type shed roof and strip coal yard horizontal direction forms the slope of gas collecting cover together, and the fixed louver exhaust port is arranged in the middle part of double slope type shed roof, and the exhaust port both sides set up the ventilation valve plate that can open and close, spray dust suppression module includes high pressure spraying device and surfactant automatic adding device, sets up a plurality of high pressure spraying device near electric valve plate and fixed louver, and simultaneously sets up the surfactant automatic adding device of matched set, monitoring and control system contains sensor and controller. The utility model can control dust, energy consumption optimization, temperature control, resource conservation.

Description

Technical Field

[0001] This utility model belongs to the field of dust control technology in strip coal yards of thermal power plants, and in particular relates to a ventilation system for strip coal yards with low coal dust leakage. Background Technology

[0002] In thermal power plants, strip coal yards are common coal storage facilities. Their conventional layout is usually a long, narrow area, equipped with equipment such as stacker-reclaimers and coal pushers. Stacker-reclaimers are responsible for stacking and retrieving coal, while coal pushers are responsible for turning and pushing the coal pile.

[0003] There are two main sources of dust in coal yards. First, the processes of stockpiling, reclaiming, and turning coal cause dust dispersion, especially fine dust particles smaller than 10μm. Due to their small size, these particles are more easily suspended in the air and dispersed by the airflow within the strip-shaped coal yard. Second, when the coal yard is in standby mode, natural drafts from the prevailing wind direction can intrude into the yard. When the airflow velocity is too high, dust will be generated on the surface of the coal pile.

[0004] Traditional ventilation systems primarily consider dilution ventilation and temperature-controlled ventilation. To meet these two requirements, the ventilation area at the top or side of the coal yard is often set to be large, which leads to the unorganized leakage of dust-laden airflow, often resulting in large amounts of visible coal dust "black smoke" drifting outdoors.

[0005] During coal turning or extraction, coal piles may periodically or occasionally release flammable gases. According to the definition in GB50058 "Code for Design of Electrical Installations in Explosive Atmospheres", this situation belongs to a Class 1 flammable gas release source. When using a mechanical ventilation system, the ventilation intensity may be difficult to guarantee due to mechanical failures or power outages. In this case, the explosion hazard zone of the strip coal yard should be classified as at least Zone 2 for gas explosions and Zone 21 for dust explosions.

[0006] When a natural ventilation system is used, the ventilation reliability is stable, and the gaseous environment explosion hazard zone can be defined as a safe zone, requiring only consideration of Zone 21 dust explosion hazard zone. By adopting natural ventilation, the explosion hazard level of the strip coal yard is reduced from gas explosion protection + dust explosion protection to only dust explosion protection. This has a significant impact on the explosion protection cost of electrical equipment in the strip coal yard, and this requirement is even more prominent in international projects.

[0007] However, when using natural ventilation systems, excessively large ventilation openings can cause a large amount of coal dust to drift outdoors. While completely closing the ventilation openings reduces dust leakage, it also classifies the strip coal yard as a gas explosion hazard zone, increasing the cost of explosion-proof electrical equipment and hindering air circulation, thus increasing the likelihood of spontaneous combustion. Furthermore, dust suppression spraying is typically only implemented on the coal handling unit of the stacker-reclaimer; implementing spraying across the entire strip coal yard to suppress coal dust would be extremely costly. Therefore, balancing dust control and ventilation needs under different operating conditions to reduce coal dust leakage has become a crucial and urgent problem to solve. Utility Model Content

[0008] The purpose of this invention is to provide a system that can dynamically switch ventilation modes according to the coal yard's operating status (coal feeding / standby), reduce dust leakage and optimize temperature control, while timely discharging explosive gases from the coal yard.

[0009] To achieve the above-mentioned utility model objectives, this utility model provides a low coal dust leakage ventilation system for a strip coal yard, including a ventilation valve plate module, a spray dust suppression module, a monitoring and control system, and air inlet louvers;

[0010] The ventilation valve plate module includes multiple independent control units arranged along the length of the strip coal yard. Each independent control unit adopts a double-sloped roof structure. The double-sloped roof structure has a trapezoidal cross section when viewed from the side. The double-sloped roof and the arc-shaped cross section of the strip coal yard together form a sloping gas collection hood. A fixed louvered exhaust port is set in the middle of the double-sloped roof, and an openable and closable ventilation valve plate is set on both sides of the exhaust port.

[0011] The dust suppression spray module includes a high-pressure spray device and an automatic surfactant addition device. Multiple high-pressure spray devices are installed near the electric valve plate and the fixed louvers, and an automatic surfactant addition device is also provided.

[0012] The monitoring and control system includes sensors and a controller. The sensors include a dust concentration sensor, a temperature sensor, and an explosive gas concentration sensor in the coal yard. The controller is connected to the dust concentration sensor, the temperature sensor, the explosive gas concentration sensor, the ventilation valve plate module, the high-pressure spray device, and the surfactant automatic addition device.

[0013] The air inlet louvers are installed on the lower side of the coal yard.

[0014] The controller is used to receive signals from dust concentration sensors, temperature sensors, and explosive gas concentration sensors in the coal yard, and sends control signals to the ventilation valve plate module, high-pressure spray device, and surfactant automatic addition device after making judgments based on the settings.

[0015] The controller is used to send a closing signal to the ventilation valve plate module of the work area during the operation period, and at the same time send a start signal to the spray device. The surfactant automatic addition device simultaneously injects surfactant with a concentration of 0.1%-0.5% into the spray device to form a fog curtain.

[0016] The controller is used to send a shut-off signal to the spray device during standby. When the temperature in the coal yard is >35℃ and the dust concentration is <set dust threshold, it sends an open signal to the ventilation valve plate module. Air enters from the air inlet louvers and exits from the ventilation valve plate module, allowing for natural ventilation and cooling. During ventilation, the dust concentration sensor monitors the dust concentration in real time and sends it to the controller. If the dust concentration exceeds the set standard, the controller sends a shut-off signal to the ventilation valve plate, which closes. The controller also sends a start signal to the surfactant automatic addition device to start the high-pressure spray device.

[0017] Furthermore, the slope of the double-sloped roof is 10°-30°.

[0018] Furthermore, the air inlet louver adopts a double-sloped blade structure with a blade tilt angle of 45°-60°.

[0019] Furthermore, the controller is configured to send a concentration increase signal to the automatic surfactant addition device when it receives a signal that the PM2.5 concentration is >20 mg / m3, thereby increasing the surfactant concentration from 0.1% to 0.3%.

[0020] Furthermore, the controller is used to send an opening signal to the ventilation valve plate when it receives a signal that the concentration of the explosive gas exceeds 10% of the lower limit of the gas explosion hazard, thereby opening the ventilation valve plate. This has a higher priority than closing the ventilation valve plate when the dust concentration exceeds the limit.

[0021] Furthermore, it also includes a first maintenance platform and a second maintenance platform. The first maintenance platform is located on both sides of the sloping gas collection hood; the second maintenance platform is located on the underside of the double-sloped roof.

[0022] The beneficial effects of this utility model are as follows:

[0023] Dust control effect: Compared with traditional ventilation systems, the amount of dust leakage during operation is greatly reduced, and the natural dust overflow during standby is also effectively controlled, significantly improving the environment around the coal yard.

[0024] Energy consumption optimization: The opening and closing of the ventilation valve plate consumes low energy. Through reasonable ventilation control strategies, unnecessary energy consumption is avoided and operating costs are reduced.

[0025] Temperature control: Ventilation during standby can control the temperature difference between indoor and outdoor coal yards, effectively reducing the risk of spontaneous combustion of coal piles and ensuring the safety of coal storage.

[0026] Resource conservation: Reduce investment in gas sensors for coal shed explosion hazards. Implement zoned dust suppression to reduce water consumption for spraying. Attached Figure Description

[0027] Figure 1 3D view of a low-dust-leakage ventilation system in a strip coal yard;

[0028] Figure 2 Cross-sectional view of a ventilation system with low coal dust leakage in a strip coal yard;

[0029] Figure 3 : Figure 2 Enlarged view of section I;

[0030] Figure 4 : Low coal dust leakage ventilation system unit for strip coal yard;

[0031] Figure 5 : Figure 4 Enlarged view of section II;

[0032] The components include: 1. Air inlet louvers; 2. Air collection hood; 3. First maintenance platform; 4. Fixed louvers; 5. Spray device; 6. Sensor; 7. Second maintenance platform; 8. Ventilation valve plate. Detailed Implementation

[0033] To better understand the purpose, structure, and function of this utility model, the following description, in conjunction with the accompanying drawings, provides a more detailed account of a low coal dust leakage ventilation system for a strip coal yard.

[0034] Reference Figures 1 to 5 It includes a ventilation valve plate module, a spray dust suppression module, and a monitoring and control system.

[0035] Ventilation Valve Panel Module: A closable cooling ventilation valve panel module is installed on the top of the strip coal yard. This module includes multiple independent control units arranged along the length of the strip coal yard. Each independent control unit adopts a double-sloped roof structure, with a trapezoidal cross-section when viewed from the side. The double-sloped roof and the transverse arc-shaped cross-section of the strip coal yard together form a sloped gas collection hood 2, used to collect and guide explosive gases such as methane and carbon monoxide to accumulate at the top of the slope. Continuous exhaust maintains the gas environment of the coal yard at a safe explosion hazard level (non-explosive hazard zone 2). A fixed louvered exhaust port 4 is installed in the middle of the double-sloped roof, and explosion-proof electric ventilation valve panels 8 are installed on both sides of the exhaust port. The fixed louvers enable continuous ventilation, ensuring the sustained and effective emission of combustible gases.

[0036] The slope of the double-sloped roof is 10°-30°, which allows for airflow control of methane and carbon monoxide gases. The total area of ​​the louvered exhaust vents on the sloping roof is calculated to ensure continuous emission of hazardous gases around the clock, with an exhaust velocity ≤0.5m / s, thus preventing airflow disturbances from causing coal dust diffusion.

[0037] The first maintenance platform 3 is set on both sides of the slope towards the gas collection hood to facilitate maintenance personnel operation and maintenance.

[0038] A second maintenance platform 7 is provided on the underside of the double-sloped roof, which is used for personnel to enter the interior for maintenance and repair.

[0039] Dust suppression spray module: A high-pressure spray device 5 is installed near the electric valve plate and fixed louvers, along with an automatic surfactant addition device. The high-pressure spray device sprays dust-laden airflow during operation to suppress dust, while the automatic surfactant addition device dynamically adjusts the solution concentration according to the dust level, improving the dust capture effect.

[0040] Monitoring and Control System: Includes sensor 6 and controller. Sensor 6 includes a dust concentration sensor, a temperature sensor, and an explosive gas concentration sensor for real-time monitoring of parameters such as dust concentration and temperature within the coal yard. By installing the dust concentration detector, temperature sensor, and explosive gas concentration sensor only below the ventilation valve plate, the sensor investment cost is significantly reduced compared to evenly distributing explosive gas sensors along the long side.

[0041] The air inlet louvers are located on the lower side of the coal yard. Their blades have a bi-sloping cross-section and an inclination angle of 45°-60°. This unique design prevents airflow from directly entering the room, altering the airflow direction and buffering the airflow to some extent, thus reducing air velocity. While allowing air to enter, it reduces the resistance to coal dust diffusion outdoors. Through the special blade angle and arrangement, a balance is achieved between ventilation and reducing coal dust diffusion.

[0042] The controller uses a PLC or DCS system to receive sensor signals. The controller is connected to the ventilation valve plate module, the high-pressure spray device, and the surfactant automatic addition device, and controls the opening and closing of the ventilation valve plate, the start and stop of the spray, and the surfactant concentration in a coordinated manner.

[0043] Work mode:

[0044] During operation (stockpiling / reclaiming / coal turning): A signal to close the ventilation valve is sent to the ventilation valve module in the operation area, leaving only the exhaust louvers near the operation area open to reduce ineffective ventilation areas and reduce the range of dust leakage; at the same time, a start signal is sent to the spray device to start the exhaust louver spray device, and a surfactant with a concentration of 0.1%-0.5% is injected simultaneously to form a fog curtain, which effectively captures fine dust by utilizing the agglomeration effect of the surfactant on dust.

[0045] Standby period (no operation): The controller sends a shutdown signal to the spray device to shut it down, avoiding resource waste; when the temperature inside the coal yard is >35℃ and the dust concentration is <set dust threshold (e.g., <40mg / m³), the spray device will shut down. 3 When the air conditioner is open, the controller sends an opening signal to the ventilation valve module, gradually opening the ventilation valve to allow for natural ventilation and cooling. Air enters through the air inlet louvers and exits through the ventilation valve module, using natural ventilation to lower the temperature of the coal yard and prevent spontaneous combustion of the coal pile. During the ventilation process, the dust concentration sensor monitors the dust concentration in real time. If the dust concentration exceeds the set standard, the controller sends a closing signal to the ventilation valve, which closes. The controller then sends a start signal to the automatic surfactant addition device to activate the high-pressure spray device, ensuring that the dust concentration is maintained within a reasonable range.

[0046] Key technical points:

[0047] Zoned control: Based on the working location, such as the coordinates of the stacker-reclaimer, the opening and closing zones of the ventilation valves are automatically switched to precisely control the ventilation range, reduce ineffective ventilation, and improve ventilation efficiency.

[0048] Slope-direction gas collection: Along the long side of the strip coal yard, each unit is made into a double slope. The double-slope roof can collect methane gas, carbon monoxide gas and other major explosive gases in the coal pile from the long side of the coal yard, effectively collecting these explosive gases.

[0049] Continuous venting: Each unit's slope top is equipped with louvered vents to achieve continuous and stable venting, ensuring that flammable and explosive gases cannot accumulate under the roof during coal extraction, turning, and pushing, thus guaranteeing the safety of the coal yard.

[0050] Ventilation as needed: When dust concentration exceeds the standard, close the valve plate and only keep the necessary louvered exhaust ports open to ensure continuous emission of hazardous gases around the clock without changing the gas environment explosion hazard level of the coal shed; when taking, turning and pushing coal, if the dust concentration exceeds the standard, close the ventilation and cooling valve plate and use the internal space of the coal yard and the intermittent coal feeding every day to allow the coal dust to settle by gravity and reduce dust emissions.

[0051] Reduced investment: Due to the reduced ventilation area, only dust concentration detectors, temperature sensors, and explosive gas concentration sensors need to be installed below the ventilation valve plate. Compared to evenly distributing explosive gas sensors along the long side, this significantly reduces sensor investment costs.

[0052] Capture efficiency: Coal dust that can be dispersed to the exhaust vent by airflow is dust with extremely small particle size distribution. By using surfactants, the capture efficiency of dust smaller than 10μm is improved, reducing water consumption for spraying and effectively controlling fine dust pollution.

[0053] Airflow organization: The louvered structure of the coal yard prevents outdoor air from blowing directly into the room, reducing the indoor velocity field, while making full use of the heat released by the oxidation reaction of the coal pile as a driving force to achieve natural ventilation.

[0054] Triggering conditions during operation: Based on the stacker-reclaimer operation signal and the coal pusher's coal turning action signal, the ventilation valve plate is closed. At this time, only the fixed ventilation louvers remain continuously open to ensure necessary ventilation. When the dust concentration exceeds the standard, the micro-mist dust suppression system is activated, maintaining only the necessary ventilation capacity to expel explosive gases, while allowing most coal dust particles to fall back into the coal pile by gravity settling.

[0055] Standby ventilation valve opening conditions: No work signal for 30 consecutive minutes, average coal yard temperature > 32℃ and PM10 concentration < 30mg / m³ 3 When needed, activate the ventilation valve panel for ventilation.

[0056] Surfactant addition logic: When PM2.5 concentration > 20 mg / m³ is detected. 3 When the controller receives the signal, it sends a concentration increase signal to the automatic surfactant addition device, increasing the surfactant concentration from 0.1% to 0.3% to enhance the capture effect of fine dust.

[0057] The explosion hazard gas concentration sensor primarily detects methane and carbon monoxide gases. When the concentration exceeds 10% of the lower limit of the gas explosion hazard, it sends an opening signal to the ventilation valve, causing the valve to open. This has higher priority than closing the ventilation valve when the dust concentration exceeds the limit.

[0058] Summary of Innovation Points

[0059] Working condition linkage control: For the first time, the coal yard coal loading operation status is dynamically coupled with the ventilation system to achieve intelligent switching of "dust control priority during operation and ventilation priority during standby", accurately meeting the needs of different working conditions.

[0060] Coal dust leakage reduction: By using ventilation valve plates for zoned control and localized spray enhancement, indiscriminate dust suppression throughout the coal yard is avoided, resource utilization efficiency is improved, energy and resource waste is reduced, and coal dust leakage at ventilation openings is further reduced.

[0061] Dust and temperature control are combined: It solves the problems of dust leakage and coal pile temperature rise at the same time, meets the dual requirements of environmental protection and safe production, and ensures the sustainable operation of the coal yard.

[0062] Double-slope gas collection and emission: A double-slope roof is installed along the length of the strip coal yard. Utilizing the buoyancy of methane and carbon monoxide, the main explosive gases in the coal pile, which are less dense than air, the gases naturally rise up the slope. Fixed, normally open louvers are installed at the top of the slope as continuous emission outlets, ensuring reliable continuous emission of explosive gases under any operating condition. This reduces the classification of the gas explosion hazard zone in the strip coal yard and lowers the investment cost for explosion-proof electrical equipment.

Claims

1. A low-dust-leakage ventilation system for a strip coal yard, characterized in that: Includes ventilation valve plate module, spray dust suppression module, monitoring and control system, and air inlet louvers (1); The ventilation valve plate module includes multiple independent control units set along the length of the strip coal yard. Each independent control unit adopts a double-slope roof structure. The double-slope roof structure has a trapezoidal cross section when viewed from the side. The double-slope roof and the arc-shaped cross section of the strip coal yard together form a slope-oriented gas collection hood (2). A fixed louvered exhaust port is set in the middle of the double-slope roof. Openable and closable ventilation valve plates (8) are set on both sides of the exhaust port. The dust suppression spray module includes a high-pressure spray device (5) and an automatic surfactant addition device. Multiple high-pressure spray devices (5) are set near the electric valve plate and the fixed louver, and an automatic surfactant addition device is also set up. The monitoring and control system includes sensors (6) and a controller. The sensors (6) include a dust concentration sensor, a temperature sensor and an explosive gas concentration sensor in the coal yard. The controller is connected to the dust concentration sensor, the temperature sensor, the explosive gas concentration sensor, the ventilation valve plate module, the high-pressure spray device and the surfactant automatic addition device. Air inlet louvers (1) are installed on the lower side of the coal yard; The controller is used to receive signals from dust concentration sensors, temperature sensors, and explosive gas concentration sensors in the coal yard, and sends control signals to the ventilation valve plate module, high-pressure spray device, and surfactant automatic addition device after making judgments based on the settings. The controller is used to send a closing signal to the ventilation valve plate module of the work area during the operation period, and at the same time send a start signal to the spray device. The surfactant automatic addition device simultaneously injects surfactant with a concentration of 0.1%-0.5% into the spray device to form a fog curtain. The controller is used to send a shutdown signal to the spray device (5) during standby. When the temperature in the coal yard is >35℃ and the dust concentration is <set dust threshold, it sends an opening signal to the ventilation valve plate module. Air enters from the air inlet louver and exits from the ventilation valve plate module, allowing for natural ventilation and cooling. During ventilation, the dust concentration sensor monitors the dust concentration in real time and sends it to the controller. If the dust concentration exceeds the set standard, the controller sends a shutdown signal to the ventilation valve plate, and the ventilation valve plate closes. The controller then sends a start signal to the surfactant automatic addition device to start the high-pressure spray device.

2. The low coal dust leakage ventilation system for a strip coal yard according to claim 1, characterized in that: The slope of the double-sloped roof is 10°-30°.

3. The low coal dust leakage ventilation system for a strip coal yard according to claim 1, characterized in that: The air inlet louver (1) adopts a double-sloped blade structure with a blade tilt angle of 45°-60°.

4. A low-dust-leakage ventilation system for a strip coal yard according to claim 1, characterized in that: The controller is used to detect dust concentrations (PM2.5) > 20 mg / m³. 3 When the signal is received, a concentration increase signal is sent to the automatic surfactant addition device to increase the surfactant concentration from 0.1% to 0.3%.

5. A low-dust-leakage ventilation system for a strip coal yard according to claim 1, characterized in that: The controller is used to send an opening signal to the ventilation valve plate (8) when it receives a gas concentration exceeding 10% of the lower limit of gas explosion hazard, thereby opening the ventilation valve plate. The priority of the ventilation valve plate is higher than that of the dust concentration exceeding the limit.

6. A low-dust-leakage ventilation system for a strip coal yard according to any one of claims 1 to 5, characterized in that: It also includes a first maintenance platform (3) and a second maintenance platform (7). The first maintenance platform (3) is set on both sides of the sloping gas collection hood; the second maintenance platform (7) is set on the underside of the double-sloped roof.

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