Method and system for suppressing burning explosion of underground cavern of pumped storage power station

Abstract

The invention provides a blast suppression method and system for an underground cavity of a pumped storage power station. The method comprises the following steps: configuring and deploying a multispectral gas sensor array; carrying out gas explosion limit calculation and risk assessment; calculating the risk level of explosion by using the prediction model; performing graded explosion suppression operation by using a graded explosion suppression execution module; combustible gas is guided to enter an inerting area by utilizing a space flow guide optimization module; and the ignition source blocking module is used for cooperative control to block an ignition source. The technical problems of low mixed gas explosion risk prediction and monitoring precision, low explosion suppression efficiency, slow response speed and relatively high operation and maintenance cost are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system safety, and in particular to a method and system for suppressing explosions in underground caverns of pumped storage power stations. Background Art

[0002] Pumped-storage power stations are a widely used, clean, and efficient method of electricity storage. Their primary function is to balance grid loads by shifting peak loads and filling valleys, achieving efficient utilization of electricity. A pumped-storage power station primarily consists of an upper reservoir, a lower reservoir, a water inlet, a water diversion pipeline, a generator set, and a water outlet. Core equipment includes a large reversible pump-turbine, a generator motor, and a cooling system. During power station operation, the pump-turbine converts kinetic energy of water into electrical energy to pump water and generate electricity.

[0003] Pumped-storage power stations, as core facilities for peak and frequency regulation of the power grid, operate their generator sets, transformers, cables, and other equipment under long-term high-load cycling conditions. During operation, organic materials such as insulating materials (epoxy resins and rubber seals) and lubricating oils can decompose due to localized overheating or electrochemical corrosion, releasing flammable gases such as methane (CH4), hydrogen (H2), and carbon monoxide (CO). These gases can easily form explosive mixtures in confined spaces (such as underground powerhouses and cable corridors). If they encounter electrical discharges from electrical equipment or mechanical sparks, they can cause serious explosions and ignite, threatening the safe operation of the power station.

[0004] In summary, the existing technology has technical problems such as low accuracy in predicting and monitoring the risk of mixed gas explosion, low explosion suppression efficiency, slow response speed, and high operation and maintenance costs. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: how to solve the technical problems in the prior art of mixed gas explosion risk prediction and monitoring with low accuracy, low explosion suppression efficiency, slow response speed and high operation and maintenance costs.

[0006] The present invention solves the above technical problems by adopting the following technical solutions: A method for suppressing explosion in an underground cavern of a pumped storage power station comprises:

[0007] In the explosion monitoring suppression area, a multi-spectral gas sensor array is configured and deployed to obtain the concentration values ​​of each gas component c1, c2, ..., c n ;

[0008] Introduce environmental compensation factors, according to the concentration values ​​of each gas component c1, c2, ..., c n , calculate the gas explosion limit, perform dynamic correction operation on the explosion limit formula of the gas explosion limit, and obtain the dynamic calculation result of the explosion limit;

[0009] Construct and use the gas concentration change trend prediction model, according to the concentration values ​​of each gas component c1, c2, ..., c n , calculate and establish a trend prediction model for gas concentration changes based on the risk level of explosion to define the risk growth rate, and obtain a comprehensive assessment risk value based on the dynamic calculation results of the explosion limit and the risk growth rate;

[0010] S4. In the explosion suppression system, the graded explosion suppression execution module is used to perform graded explosion suppression operations based on the comprehensive risk assessment value.

[0011] The present invention develops an explosion suppression system that integrates dynamic monitoring, graded inerting, and intelligent linkage. Through a high-precision sensor array, dynamic modeling of explosion limits, and spatial diversion optimization, it achieves multi-modal collaborative prevention and control, as well as a full-chain prevention and control system of dynamic monitoring-intelligent decision-making-graded suppression-spatial optimization, fundamentally improving the safety level of power plants.

[0012] In a more specific technical solution, a multi-spectral gas sensor array is configured and deployed in the explosion monitoring suppression area to obtain the concentration values ​​of each gas component c1, c2, ..., c n In the step, the explosion monitoring and suppression area includes at least one of the following: a generator set, a transformer room and a cable mezzanine of a pumped storage power station.

[0013] In a more specific technical solution, in S2, the explosion limit range of the combustible gas is calculated in real time, and based on the environmental compensation factor, the lower explosion limit LEL and the upper explosion limit UEL are dynamically corrected using the following logic to obtain the dynamic calculation result of the explosion limit.

[0014] Specifically, the following logic is used to dynamically correct the lower explosion limit LEL to obtain the dynamic calculation result of the explosion limit:

[0015]

[0016] Where, V i is the volume fraction of combustible gas i, c i is the concentration of combustible gas i, LEL i is the lower explosion limit of combustible gas i, T is the ambient temperature (°C), P is the air pressure (kPa), and H is the humidity (%RH).

[0017] The present invention uses a multi-spectral sensor array to monitor the concentrations of combustible components such as H2, CH4, and CO in real time, and combines environmental compensation such as temperature, humidity, and air pressure to dynamically correct the upper and lower explosion limits of the mixed gas, realizing the "multi-component-dynamic threshold" adaptive explosion suppression principle for threshold judgment, overcoming the unsuitability of the static single inerting method in the literature for complex power station operating conditions.

[0018] T0 is the reference temperature (preferably 25°C); αT The temperature correction coefficient ranges from 0.002 to 0.006, preferably 0.004; P0 is standard atmospheric pressure (101.3 kPa); humidity correction coefficient α T The value range is 0.0005-0.0015, preferably 0.001; the value range of the air pressure correction index β is 0.2-0.5, preferably 0.3.

[0019] Because the traditional Richardtree formula for the explosion limit of mixed gases typically uses fixed values ​​and lacks environmental adaptability, this paper proposes a dynamically corrected explosion limit calculation model based on complex environmental factors such as high underground humidity in pumped-storage power plants. Specifically, this paper introduces environmental compensation factors such as temperature, humidity, and air pressure, and constructs a corrosion compensation sub-function. This enables dynamic calculation and real-time correction of the explosion limit, significantly improving the accuracy of detecting the explosion risk of mixed combustible gases.

[0020] The present invention is aimed at the explosion risk of mixed combustible gases in pumped-storage power stations. It needs to deal with the dynamic evolution of multi-component gases in a complex and closed environment. It introduces a dynamic explosion limit correction model (temperature / humidity / air pressure compensation), a multi-spectral sensor array and spatial diversion optimization to achieve precise monitoring and active intervention.

[0021] In a more specific technical solution, a gas concentration change trend prediction model is constructed and used, and the gas concentration values ​​c1, c2, ..., c n , calculate and establish a gas concentration change trend prediction model based on the risk level of explosion to define the risk growth rate, and in the step of obtaining a comprehensive risk assessment value based on the dynamic calculation result of the explosion limit and the risk growth rate, establish a gas concentration change trend prediction model and define the risk growth rate using the following logic:

[0022]

[0023] Where c t is the current gas concentration determined according to the gas concentration change trend prediction model, avg(c t-3→t-1 ) is the average concentration over the past three time points, and Δt is the time interval. The risk growth rate α is calculated independently for each combustible gas, and the final risk level of the system is determined by the largest α value.

[0024] The present invention dynamically modifies the explosion limit model (introducing temperature / humidity / pressure compensation factors), combines it with a multispectral sensor array to monitor multi-component gas concentrations and trend predictions (risk growth rate α) in real time, and triggers graded explosion suppression (inerting, aerosol spraying, and dual-mode fire extinguishing). This solves the core issues of inaccurate prediction of mixed gas explosion risks, delayed response, and high re-ignition risks, significantly improving explosion suppression efficiency and safety in complex environments.

[0025] Specifically, the risk growth rate calculation method adopted by the present invention is different from the existing technology. It is an independent short-period concentration growth rate modeling method proposed for the dynamic evolution characteristics of multi-component combustible gases in the confined space of a pumped storage power station. The present invention collects the difference between the current gas concentration and the mean concentration of the previous three historical time points in real time, combines the time interval, quantifies the gas risk growth rate, and uses the maximum growth rate value as a comprehensive assessment of the risk value to determine the system warning level. Compared with the existing method of judging the explosion risk based on only a single gas static concentration threshold, the aforementioned model adopted by the present invention has stronger predictive ability, higher multi-gas adaptability and lower false triggering rate, which significantly improves the feedforward response level and operational safety of the explosion suppression system.

[0026] Here’s how it works:

[0027] Temperature Correction: This term reflects the effect of rising ambient temperature on the activation energy of the combustion reaction. As temperature rises, the kinetic energy of combustible gas molecules increases, making it easier for them to reach ignition conditions, resulting in a downward trend in the lower explosion limit. This correction term is linear, with the LEL decreasing as temperature increases, consistent with actual combustion dynamics.

[0028] Water vapor has a diluting effect, reducing the effective ratio of combustible gas to oxygen per unit volume, and has a certain inerting effect, making combustion more difficult to occur, which manifests as a slight increase in the LEL. This item uses a linear compensation method to reflect the explosion suppression effect brought about by increased humidity.

[0029] This indicator characterizes the effect of changes in ambient pressure on the reactivity of combustible gases. As pressure decreases, the molecular density of reactants decreases, reducing the probability of combustion and causing the LEL to rise. An inverse exponential term is used to correct for the pressure-dependent change in the lower explosion limit.

[0030] Through the joint correction of the above three factors, the dynamic model of the lower explosion limit constructed by the present invention can be used to update the effective LEL value under the current environment in real time, realize dynamic and accurate perception of the explosion risk of mixed combustible gases, and provide basic data support for subsequent explosion warning and explosion suppression response.

[0031] According to the risk growth rate and the dynamic calculation results of the explosion limit, the following calculation formula is used to obtain the comprehensive assessment risk value:

[0032] R=0.7×LEL+0.3×α

[0033] When the comprehensive risk assessment value meets the preset trigger conditions, the system automatically triggers an early warning and performs a linkage operation of the explosion suppression system, where LEL represents the lower explosion limit. The present invention can achieve multi-dimensional risk suppression. Specifically, traditional explosion suppression systems rely on a single gas concentration threshold to judge the risk of explosion, which is prone to misjudgment due to changes in gas type and environmental conditions. The present invention is based on a multi-spectral gas sensor array, combined with a dynamically corrected explosion limit calculation model and a risk trend prediction algorithm, to achieve a comprehensive risk assessment of mixed combustible gases, greatly improving the accuracy and safety of monitoring.

[0034] In a more specific technical solution, the hierarchical explosion suppression execution module includes: a first-level inerting unit, a second-level explosion suppression unit, and a third-level active suppression unit.

[0035] In a more specific technical solution, when the concentration of any combustible gas reaches the preset range of its lower explosion limit LEL, and the corresponding risk growth rate meets the preset conditions, and the gas concentration change trend prediction model shows that the gas risk is increasing, the first-level inerting unit is activated, and based on the comprehensive assessment of the risk value, the working state of the nitrogen generator is adjusted to suppress the gas combustion and explosion chain reaction, completing the first-level explosion suppression operation.

[0036] In a more specific technical solution, when the preset conditions are met, the secondary explosion suppression unit is activated, and according to the dynamic calculation results of the explosion limit, a mixed gas mist of perfluorohexanone C6F12O and CO2 is sprayed through the pre-buried pipeline to suppress the explosion.

[0037] In a more specific technical solution, the preset conditions include: the concentration of any combustible gas reaches a preset proportion range of the lower explosion limit of the combustible gas, and the comprehensive assessment risk value is not less than a preset threshold.

[0038] Specifically, when the concentration of any combustible gas reaches 60% to 80% of its lower explosion limit (LEL), and the corresponding risk growth rate is a i When the concentration is ≥0.02 (unit concentration / minute), the system determines that the gas has a tendency to accumulate rapidly; at this time, the first-level inerting unit is activated, and the gas production rate of the nitrogen generator is adjusted to reduce the oxygen concentration to below 18%, thereby interrupting the formation conditions of the explosion chain reaction.

[0039] In a more specific technical solution, in S4, when the concentration of any combustible gas reaches more than 90% of its lower explosion limit and the comprehensive assessment risk value R≥0.85, the system determines that it is in a high-risk state. At this time, the secondary explosion suppression unit is activated and perfluorohexanone C6F is sprayed through the pre-buried pipeline. 12 The explosion is suppressed by a mixture of O and CO2.

[0040] This invention utilizes a composite aerosol composed of perfluorohexanone and carbon dioxide in its secondary explosion suppression operation, replacing the single inert gas (such as nitrogen or CO2) commonly used in traditional technologies. Pre-embedded directional injection microtubes enable targeted, quantitative, and efficient release. Furthermore, the activation mechanism of the secondary explosion suppression unit no longer relies on a single gas concentration threshold. Instead, it uses a dynamic lower explosion limit calculation coupled with a comprehensive risk assessment, significantly improving the accuracy and lead time of triggering decisions.

[0041] Compared with the existing technology, the two-stage explosion suppression operation method of the present invention has the following advantages: first, the explosion suppression medium is composite, which can achieve the triple effects of inerting, cooling and fire extinguishing without damaging the equipment; second, the response mechanism is more intelligent and can actively intervene before the explosion occurs to prevent the system from entering an uncontrollable state.

[0042] Principle: The system collects gas concentration and environmental parameters in real time through sensors, dynamically corrects the lower explosion limit, and calculates the comprehensive risk value (R) based on the trend of gas concentration changes. When R exceeds the set threshold, the system activates the secondary explosion suppression operation before the combustible gas reaches the explosion range, and the C6F 12 Rapid intervention with a mixture of oxygen and CO2 aerosol: C6F 12 O2 interrupts the combustion reaction chain by absorbing heat and inhibiting free radicals, and CO2 further reduces the probability of combustion and explosion by diluting oxygen and combustible components.

[0043] In a more specific technical solution, when any sensor captures that the concentration of mixed combustible gas enters the range of the dynamic calculation results of the explosion limit, and the comprehensive assessment risk value R is not less than the preset threshold, the three-level active suppression unit is activated, and the high-frequency pressure sensor is used to capture the explosion shock wave signal in real time, triggering the dual-mode injection of ultra-fine water mist and ABC dry powder.

[0044] Specifically, the three-stage active suppression unit: When any sensor detects that the concentration of the mixed combustible gas falls within the range specified by the dynamic calculation results of the explosion limit, and R ≥ 0.95, the system enters critical combustion and explosion monitoring mode. If the high-frequency pressure sensor detects a deflagration shock wave signal, the system immediately activates the three-stage active suppression unit, triggering a dual-mode injection of ultrafine water mist and ABC dry powder to form a physical explosion-proof barrier and rapidly cool down the fire to extinguish it.

[0045] The present invention aims at the working conditions where the gas concentration is close to the explosion limit and there are precursors to deflagration, and adopts a technical solution that combines high-frequency pressure wave detection with a fast linkage injection mechanism. The system monitors the precursor signal of the deflagration shock wave (such as a short-term high-amplitude gradient pressure wave) in real time through a high-frequency dynamic pressure sensor, and triggers the explosion suppression device with a response delay of milliseconds to release a combination of ultra-fine water mist and ABC dry powder fire extinguishing agent. The injection adopts a dual-mode nozzle structure, which can achieve the coexistence of mist coverage and particle impact, ensuring that the reaction chain is quickly cut off at the early stage of the deflagration, controlling local high temperature and flame spread. It has the advantages of fast response, thorough extinguishing, and multi-channel coverage.

[0046] Principle: By monitoring microsecond-level pressure changes (such as supersonic precursor waves or microseisms that precede a gas explosion) through high-frequency pressure sensors, critical signs of an impending explosion can be identified before the appearance of open flames or acoustic or visual signals. Upon identification, the system quickly activates and triggers synchronized injection. Two types of explosion suppression media work together, combined with a highly efficient nozzle layout and a rapid-response control system, to form an active deflagration suppression method with advanced identification, rapid response, and broad-spectrum control capabilities, significantly enhancing the system's safety capabilities in extremely hazardous operating conditions.

[0047] In a more specific technical solution, a spatial flow diversion optimization module is used to guide the combustible gas into the inerting zone, wherein the spatial flow diversion optimization module includes:

[0048] An intelligent deflector array dynamically adjusts the inclination angle according to the gas concentration distribution, using the Bernoulli effect to guide the gas into the inerting zone;

[0049] The negative pressure gas collecting chamber is used to generate local negative pressure through the Venturi accelerator to carry out directional migration of combustible gas.

[0050] This invention reduces the operation and maintenance costs of explosion suppression systems. Specifically, it optimizes the utilization efficiency of explosion suppression resources and reduces unnecessary inerting agent consumption. Furthermore, the Venturi negative pressure structure, combined with the dynamic adjustment of the deflector, and the passive diversion structure reduce the energy consumption of the ventilation system. The perfluorohexanone condensation recovery device enables the recycling of the fire extinguishing agent, reducing chemical emissions and significantly reducing long-term operation and maintenance costs.

[0051] The present invention uses a broadband current sensor to monitor the discharge signal of the equipment and combines it with infrared thermal imaging to identify abnormal arcs. When it is detected that the discharge energy is greater than a preset threshold, the graphene solid-state circuit breaker is triggered, and the secondary explosion suppression unit in the partition is linked to pre-release the inert medium.

[0052] This invention optimizes the response speed of the explosion suppression system. Specifically, it uses a broadband current sensor combined with infrared thermal imaging technology to quickly identify abnormal arcs. A graphene solid-state circuit breaker (breaking time <3ms) quickly cuts off the power supply. Simultaneously, the explosion suppression system is linked to release the inerting medium in advance, ensuring that explosion conditions are blocked within millisecond response times, significantly reducing the risk of ignition sources.

[0053] In a more specific technical solution, the underground cavern explosion suppression system of a pumped storage power station includes:

[0054] Multispectral gas sensing module is used to configure and deploy a multispectral gas sensor array in the explosion monitoring suppression area to obtain the concentration values ​​of each gas component c1, c2, ..., c n ;

[0055] The explosion limit dynamic processing module is used to introduce the environmental compensation factor according to the concentration values ​​of each gas component c1, c2, ..., c n , calculate the gas explosion limit, perform a dynamic correction operation on the explosion limit formula of the gas explosion limit, obtain the dynamic calculation result of the explosion limit, connect the explosion limit dynamic processing module with the multi-spectral gas sensing module, and connect the explosion limit dynamic processing module with the multi-spectral gas sensing module;

[0056] Risk level prediction module is used to build and use the gas concentration change trend prediction model, according to the concentration values ​​of each gas component c1, c2, ..., c n , calculate the risk level of explosion, establish a trend prediction model for gas concentration changes to define the risk growth rate, and obtain a comprehensive assessment risk value based on the dynamic calculation results of the explosion limit and the risk growth rate. The risk level prediction module is connected to the multi-spectral gas sensing module;

[0057] The graded explosion suppression execution module is used to perform graded explosion suppression operations according to the risk level. The graded explosion suppression execution module includes: a first-level inerting unit, a second-level explosion suppression unit and a third-level active suppression unit. The graded explosion suppression execution module is connected to the risk level prediction module.

[0058] In a more specific technical solution, in the multi-spectral gas sensing module, the explosion monitoring and suppression area includes at least one of the following: a generator set, a transformer room, and a cable mezzanine of a pumped storage power station.

[0059] In a more specific technical solution, the risk level prediction module includes:

[0060] The risk growth rate definition module is used to establish a gas concentration trend prediction model and define the risk growth rate using the following logic:

[0061]

[0062] Where c t is the current gas concentration, avg(c t-3→t-1 ) is the average concentration of the past three time points, Δt is the time interval, and the risk growth rate α is calculated independently for each combustible gas. The final risk level of the system is determined by the largest α value;

[0063] The risk assessment module is used to obtain a comprehensive risk assessment value based on the risk growth rate and explosion limit dynamic calculation results using the following calculation formula:

[0064] R=0.7×LEL+0.3×α

[0065] The risk assessment module is connected to the risk growth rate definition module;

[0066] The explosion suppression trigger module is used to automatically trigger an early warning when the comprehensive assessment risk value meets the preset trigger conditions, and perform linkage operations on the explosion suppression system. The explosion suppression trigger module is connected to the assessment risk module.

[0067] In a more specific technical solution, the hierarchical explosion suppression execution module includes: a first-level inerting unit, a second-level explosion suppression unit, and a third-level active suppression unit.

[0068] In a more specific technical solution, the first-level inerting unit is used to activate the first-level inerting unit when the concentration of any combustible gas reaches the preset range of its lower explosion limit LEL, and the corresponding risk growth rate meets the preset conditions, and the gas concentration change trend prediction model shows that the gas risk is increasing. According to the comprehensive assessment of the risk value, the working state of the nitrogen generator is adjusted to suppress the gas combustion and explosion chain reaction, thereby completing the first-level explosion suppression operation.

[0069] In a more specific technical solution, the secondary explosion suppression unit is used to activate the secondary explosion suppression unit when the preset conditions are met, and to suppress the explosion by spraying a mixed gas mist of perfluorohexanone C6F12O and CO2 through the pre-buried pipeline according to the dynamic calculation results of the explosion limit.

[0070] In a more specific technical solution, the preset conditions of the secondary explosion suppression unit include: the concentration of any combustible gas reaches a preset proportion range of the lower explosion limit of the combustible gas, and the comprehensive assessment risk value is not less than a preset threshold.

[0071] In a more specific technical solution, the three-level active suppression unit is used to start the three-level active suppression unit when any sensor captures that the concentration of mixed combustible gas enters the range of the dynamic calculation result of the explosion limit, and the comprehensive assessment risk value R is not less than the preset threshold. The high-frequency pressure sensor is used to capture the explosion shock wave signal in real time and trigger the dual-mode injection of ultra-fine water mist and ABC dry powder.

[0072] In a more specific technical solution, the explosion suppression system for the underground cavern of a pumped storage power station also includes: a spatial diversion optimization module for guiding the combustible gas into the inerting area; the spatial diversion optimization module includes:

[0073] An intelligent deflector array dynamically adjusts the inclination angle according to the gas concentration distribution, using the Bernoulli effect to guide the gas into the inerting zone;

[0074] The negative pressure gas collecting chamber is used to generate local negative pressure through the Venturi accelerator to carry out directional migration of combustible gas.

[0075] In a more specific technical solution, the explosion suppression system for underground caverns in pumped-storage power stations also includes: an ignition source blocking module, which is used for coordinated control, blocking the ignition source, using a broadband current sensor to monitor the equipment discharge signal, and combining infrared thermal imaging to identify abnormal arcs; when it is detected that the discharge energy is greater than the preset threshold, the graphene solid-state circuit breaker is triggered, and the secondary explosion suppression unit in the partition is linked to pre-release the inert medium.

[0076] Compared with the prior art, the present invention has the following advantages:

[0077] The present invention develops an explosion suppression system that integrates dynamic monitoring, graded inerting, and intelligent linkage. Through a high-precision sensor array, dynamic modeling of explosion limits, and spatial diversion optimization, it achieves multi-modal collaborative prevention and control, as well as a full-chain prevention and control system of dynamic monitoring-intelligent decision-making-graded suppression-spatial optimization, fundamentally improving the safety level of power plants.

[0078] This invention enables multi-dimensional risk suppression. Specifically, traditional explosion suppression systems often rely on a single gas concentration threshold to determine explosion risk, which can easily lead to misjudgments due to variations in gas type and environmental conditions. This invention, based on a multispectral gas sensor array and combined with a dynamically corrected explosion limit calculation model and a risk trend prediction algorithm, achieves a comprehensive risk assessment of mixed combustible gases, significantly improving monitoring accuracy and safety.

[0079] This invention reduces the operation and maintenance costs of explosion suppression systems. Specifically, it optimizes the utilization efficiency of explosion suppression resources and reduces unnecessary inerting agent consumption. Furthermore, the Venturi negative pressure structure, combined with the dynamic adjustment of the deflector, and the passive diversion structure reduce the energy consumption of the ventilation system. The perfluorohexanone condensation recovery device enables the recycling of the fire extinguishing agent, reducing chemical emissions and significantly reducing long-term operation and maintenance costs.

[0080] This invention optimizes the response speed of the explosion suppression system. Specifically, it uses a broadband current sensor combined with infrared thermal imaging technology to quickly identify abnormal arcs. A graphene solid-state circuit breaker (breaking time <3ms) quickly cuts off the power supply. Simultaneously, the explosion suppression system is linked to release the inerting medium in advance, ensuring that explosion conditions are blocked within millisecond response times, significantly reducing the risk of ignition sources.

[0081] The present invention realizes more precise, pre-positioned and partitioned intelligent explosion suppression control by constructing a dynamic correction model of explosion limits, integrating risk assessment and risk growth rate linkage judgment, and combining spatial diversion optimization with graded multimodal explosion suppression units (nitrogen inerting, composite aerosol, ultrafine water mist + dry powder). This effectively compensates for the defects of the existing technology in risk identification lag, rough response and insufficient spatial explosion suppression, and significantly improves the adaptability, safety and control accuracy of the system.

[0082] The present invention deploys a multi-spectral gas sensor array for real-time multi-component monitoring, constructs a dynamic correction model for explosion limits under environmental compensation such as temperature, humidity, and air pressure, and a gas concentration change trend prediction model, thereby achieving accurate judgment of the explosion boundary and risk trend warning; and combines graded inerting, C6F 12 The full-chain linkage control including O / CO2 mixed aerosol, ultra-fine water mist + dry powder multi-modal explosion suppression unit, intelligent guide plate and negative pressure gas collecting chamber to coordinately optimize the airflow path, as well as broadband current sensing + graphene solid-state circuit breaker <3ms ignition blocking significantly improves the response speed, explosion suppression efficiency and resource utilization, fundamentally making up for the shortcomings of comparative technology in forward-looking identification and active intervention.

[0083] The present invention solves the technical problems existing in the prior art of mixed gas explosion risk prediction and monitoring with low accuracy, low explosion suppression efficiency, slow response speed and high operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 This is a schematic diagram of the basic steps of the method for suppressing explosion in an underground cavern of a pumped storage power station according to Example 1 of the present invention;

[0085] Figure 2 This is a schematic diagram of the system topology of the explosion suppression safety system for the underground cavern of a pumped-storage power station according to Example 1 of the present invention;

[0086] Figure 3 Schematic diagram of the intelligent guide plate structure and gas guide path according to Example 1 of the present invention;

[0087] Figure 4 This is a schematic diagram of the graphene solid-state circuit breaker and explosion suppression linkage principle of Example 1 of the present invention. DETAILED DESCRIPTION

[0088] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0089] Example 1

[0090] like Figure 1 and Figure 2 As shown, the method for suppressing explosion in an underground cavern of a pumped storage power station provided by the present invention includes the following basic steps:

[0091] S1. In the explosion monitoring suppression area, configure and deploy a multi-spectral gas sensor array to obtain the concentration values ​​c1, c2, ..., c n ;

[0092] In this embodiment, a multispectral gas sensor array is deployed in areas prone to the accumulation of combustible gas, including but not limited to:

[0093] TDLAS laser gas analyzers (model: GA-2100) are installed in groups every 5 meters to detect the absorption spectra of CH4 and H2 (wavelength range: 1650nm-2200nm), with a sampling frequency of 10Hz and an accuracy of ±0.5%FS.

[0094] In this embodiment, an electrochemical sensor array (Honeywell XNX-C) detects CO concentration (range 0-1000 ppm) and oxygen concentration (range 15%-25%), and the data is transmitted to the edge computing node via the RS-485 bus.

[0095] Specifically, the aforementioned areas where combustible gas accumulates include, but are not limited to: generator sets, transformer rooms, and cable interlayers in power stations.

[0096] S2, introduce environmental compensation factors, according to the concentration values ​​of each gas component c1, c2, ..., c n , calculate the gas explosion limit, perform dynamic correction operation on the explosion limit formula of the gas explosion limit, and obtain the dynamic calculation result of the explosion limit;

[0097] In this embodiment, the explosion limit range of the combustible gas is calculated in real time. Based on the environmental compensation factor, the lower explosion limit LEL is dynamically corrected using the following logic to obtain the dynamic calculation result of the explosion limit:

[0098]

[0099] Where, V i is the volume fraction of combustible gas i, c i is the concentration of combustible gas i, LEL i is the lower explosion limit of combustible gas i, T is the ambient temperature (°C), P is the air pressure (kPa), and H is the humidity (%RH).

[0100] T0 is the reference temperature (preferably 25°C); α T The temperature correction coefficient ranges from 0.002 to 0.006, preferably 0.004; P0 is standard atmospheric pressure (101.3 kPa); humidity correction coefficient α T The value range is 0.0005-0.0015, preferably 0.001; the value range of the pressure correction index β is 0.2-0.5, preferably 0.3S3, using the prediction model to calculate the risk level of explosion;

[0101] S3, build and use the gas concentration change trend prediction model, according to the concentration values ​​of each gas component c1, c2, ..., c n , calculate and establish a trend prediction model for gas concentration changes based on the risk level of explosion, define the risk growth rate, and obtain a comprehensive assessment risk value based on the dynamic calculation results of the explosion limit and the risk growth rate;

[0102] In this embodiment, a trend prediction model for gas concentration changes is established, and the risk growth rate is defined as:

[0103]

[0104] Where c t is the current gas concentration, avg(c t-3→t-1 ) is the average concentration over the past three time points, and Δt is the time interval. The risk growth rate α is calculated independently for each combustible gas, and the final risk level of the system is determined by the largest α value.

[0105] The final comprehensive risk assessment value is:

[0106] R=0.7×LEL+0.3×α

[0107] When the R value reaches or exceeds 0.95, the system automatically triggers an early warning and activates the explosion suppression system.

[0108] S4. In the explosion suppression system, the graded explosion suppression execution module is used to perform graded explosion suppression operations based on the comprehensive risk assessment value;

[0109] In this embodiment, a first-level explosion suppression operation is performed using a first-level inerting unit;

[0110] In this embodiment, when the concentration of any combustible gas reaches 60% to 80% of its lower explosion limit (LEL), and the corresponding risk growth rate a i When the oxygen concentration is ≥0.02 (unit concentration / minute), the system automatically adjusts the working status of the nitrogen generator according to the real-time monitoring data, injects nitrogen into the target area through the fan, reduces the oxygen concentration to below 18%, and thus suppresses the combustion and explosion chain reaction of combustible gases.

[0111] In this embodiment, the technical parameters for the first-level explosion suppression operation include but are not limited to:

[0112] Nitrogen generator (gas output 30m 3 / min) is sprayed into the generator compartment through an annular distribution pipe (inner diameter 80mm). The nozzle adopts a swirl atomization design with a spray angle of 60° to ensure rapid mixing of nitrogen and air. Oxygen concentration control: PID closed-loop regulation is adopted, with a set value of 18%. When the measured value exceeds 18.5%, the nitrogen flow rate is increased to 35m 3 / min.

[0113] In this embodiment, a secondary explosion suppression unit is used to perform secondary explosion suppression operation;

[0114] In this embodiment, when the concentration of any combustible gas reaches 90% or more of its lower explosion limit and the comprehensive assessment risk value R≥0.85, the system automatically activates the secondary explosion suppression unit and uses perfluorohexanone (C6F 12 O) is mixed with CO2 to spray aerosol, and the generator set is linked to reduce load control.

[0115] In this embodiment, the technical parameters of the secondary explosion suppression operation include but are not limited to:

[0116] The pressure in the 500L perfluorohexanone and CO2 mixing tank is maintained at 2.5MPa, with release controlled by a solenoid valve (response time <10ms). The mixture ratio is 25% perfluorohexanone and 75% CO2, with an injection rate of 8kg / s and a coverage radius of 15m. Interlocking control: When the explosion limit index of the mixed gas reaches the safety threshold, the unit load is reduced. A step signal is sent to the speed regulator via the PLC, reducing the output from 300MW to 150MW in a staged manner within 30 seconds.

[0117] In this embodiment, a three-stage active suppression unit is used to perform a three-stage active suppression operation;

[0118] In this embodiment, when any sensor captures that the concentration of the mixed combustible gas enters the range of the dynamic calculation results of the explosion limit and R≥0.95, the shock wave signal is captured by a high-frequency pressure sensor (response time <1ms), triggering ultrafine water mist (particle size <50μm) + ABC dry powder to perform dual-mode injection to form a physical explosion-proof barrier.

[0119] In this embodiment, the technical parameters of the three-level active explosion suppression operation include but are not limited to:

[0120] Ultrafine water mist nozzle (Lechler 136.134.xx) with working pressure of 8MPa, droplet size Dv90 < 50μm, and coverage area of ​​50m 2 / indivual.

[0121] The ABC dry powder storage tank (capacity 100 kg) is linked with compressed air (0.6 MPa), with an injection rate of 12 kg / s, and is preferentially released upstream in the direction of pressure wave propagation.

[0122] S5. Use the spatial diversion optimization module to guide the combustible gas into the inerting area;

[0123] like Figure 3 As shown, in this embodiment, the specific components of the spatial diversion optimization module include but are not limited to:

[0124] Intelligent guide plate array; specifically, the aforementioned intelligent guide plate array is installed on the top of the corridor, which can dynamically adjust the inclination angle (0°~45°) according to the gas concentration distribution, and use the Bernoulli effect to guide the gas into the inerting area. This embodiment combines an adjustable angle mechanical guide structure with a sensor-control system - the adjustable guide plate is organically integrated with a multi-spectral sensor and closed-loop control logic to adjust the guide path in real time according to the combustible gas concentration and flow field changes. Specifically, the guide plate is made of 6061 aluminum alloy, the single plate size is 1200mm×300mm, and the surface is coated with polytetrafluoroethylene to reduce friction resistance.

[0125] The driving mechanism, specifically, adopts a stepper motor (57HS09) in combination with a harmonic reducer. Each guide plate is controlled by a set of driving units, and its structure includes: NEMA series stepper motor; cylindrical harmonic reducer; flexible wheel + wave generator + rigid wheel three-piece structure fixed between the motor output shaft and the guide plate rotating shaft; the stepper motor output is transmitted to the guide plate shaft through the harmonic reducer to achieve high resolution and low backlash precise control.

[0126] In the specific control logic of spatial diversion optimization, based on real-time concentration field data, the posture of the guide plate group is optimized through genetic algorithm, which improves the gas enrichment efficiency by 40%.

[0127] Specifically, the above genetic algorithm optimization strategy is as follows:

[0128] Variables and definitions: n, the number of deflectors; m, the number of critical areas to be protected (such as sensor / heat source areas); θ i ∈[0°, 90°], the adjustable angle of the i-th guide plate; The posture combination of the deflector group (chromosome); The residual gas concentration in region i under the current posture combination; w i , the importance weight of the i-th region.

[0129] Objective function design:

[0130]

[0131] The corresponding fitness function is defined as its reciprocal (or normalized reciprocal):

[0132]

[0133] Genetic algorithm optimization process logic:

[0134] 1. Chromosome encoding: angle θ of each guide plate i Discrete into 8 bits (can represent 256 posture values); the entire individual chromosome is an 8n-bit binary string.

[0135] 2. Initial population generation: randomly initialize k individuals (e.g., k = 50); each individual corresponds to a guide vane angle combination.

[0136] 3. Fitness calculation: Decode each individual → get posture combination Calling approximate models or local CFD predictions Calculate the objective function and fitness

[0137] 4. Genetic operations: Selection: Roulette wheel or tournament selection based on fitness probability; Crossover: Single-point or double-point crossover on chromosomes (exchanging 1-2 random positions); Mutation: Flipping random bits with a probability pm (e.g., 1-5%); Preservation strategy: Preserving the individuals with the best fitness to the next generation (elite strategy);

[0138] 5. Iterative update: Repeat the above steps until the set maximum number of generations Gmax is reached or the fitness converges.

[0139] 6. Decoding output: Output the chromosome with the best fitness, decoded as an angle combination Used to control the deflector attitude.

[0140] In this embodiment, a U-shaped negative pressure gas collecting cavity is used to carry out directional migration of combustible gas:

[0141] In this embodiment, a U-shaped negative pressure gas collecting chamber is set at the bottom of the vertical shaft, and the Venturi effect is used to form a local negative pressure (-500Pa) to directionally migrate the combustible gas.

[0142] Specifically, the throat diameter of the Venturi tube is 200 mm, the inlet expansion angle is 15°, the outlet contraction angle is 30°, and the air flow velocity is increased from 5 m / s to 25 m / s, forming a negative pressure zone of -500 Pa.

[0143] An activated carbon adsorption layer (100mm thick) is set at the bottom of the gas collecting chamber to intercept unburned particulate matter and avoid secondary pollution.

[0144] S6. Use the ignition source blocking module to perform coordinated control to block the ignition source.

[0145] like Figure 4 As shown, in this embodiment, abnormal arc detection is performed;

[0146] Specifically, a broadband current sensor is used to monitor the high-frequency harmonics of the cable. When a transient pulse of 3 MHz or above and an amplitude greater than 5 A is detected, it is determined to be a fault arc. In this embodiment, the bandwidth of the broadband current sensor can be selected, for example, DC-10 MHz;

[0147] The infrared thermal imager (FLIR A8580) scans the surface of the equipment, and the temperature gradient is >15℃ / cm 2 When the warning is triggered.

[0148] In this embodiment, rapid disconnection and explosion suppression are linked:

[0149] Specifically, the graphene solid-state circuit breaker (breaking capacity 100kA) has a built-in IGBT module that cuts off the circuit within 3ms after detecting a fault.

[0150] The circuit breaker signal is transmitted to the explosion suppression controller via optical fiber, and the secondary explosion suppression unit in the corresponding area is triggered with a delay of less than 1ms.

[0151] Example 2

[0152] In this embodiment, the system linkage and reliability are verified.

[0153] Perform control logic test:

[0154] When CH4 (concentration 1.5% vol) and H2 (concentration 2% vol) were released into a simulated environment, the system completed the following actions within 200ms:

[0155] The first stage of inerting was started, and the oxygen concentration dropped from 20.9% to 17.8%;

[0156] Adjust the guide plate to a 25° inclination angle, and the gas migration speed increases to 1.2 m / s;

[0157] The pressure wave sensor triggers the third-level explosion suppression, and the extinguishing agent coverage lag time is less than 50ms.

[0158] The actual power station comparison data is shown in the table below:

[0159]

[0160] In response to the risk that combustible gases such as methane (CH4), hydrogen (H2), and carbon monoxide (CO) released due to thermal decomposition of insulating materials or electrical failures in the confined space of the power station may form an explosive mixture, the present invention proposes a collaborative prevention and control scheme based on dynamic monitoring, intelligent prediction, graded explosion suppression and ignition source blocking. The present invention includes a multi-spectral gas sensor array to realize real-time monitoring of combustible gases and dynamic calculation of explosion limits, and early warning through a risk prediction model; the graded explosion suppression module starts nitrogen inerting, perfluorohexanone / CO2 mixed aerosol injection and ultra-fine water mist-dry powder dual-mode explosion suppression in sequence according to the risk level to ensure precise control of the explosion risk; the spatial diversion module adopts intelligent guide plates and U-shaped negative pressure gas collection cavities to optimize the gas diffusion path and reduce the high-concentration gas enrichment area; the ignition source blocking module combines a broadband current sensor with an infrared thermal imager to realize abnormal arc monitoring, and quickly cuts off the power supply through a graphene solid-state circuit breaker, while linking the explosion suppression system to release the inerting medium in advance. This invention breaks through the limitations of traditional single concentration threshold monitoring, achieves accurate prediction, rapid response and efficient explosion suppression, and can be widely used in the prevention and control of explosions in pumped-storage power stations and other confined spaces, improving safety and system reliability.

[0161] Example 3

[0162] The explosion suppression system for underground caverns of pumped storage power stations provided by the present invention includes the following basic modules:

[0163] Multispectral gas sensing module, used to configure and deploy multispectral gas sensor arrays;

[0164] In this embodiment, a multispectral gas sensor array is deployed in areas prone to the accumulation of combustible gas, including but not limited to:

[0165] TDLAS laser gas analyzers (model: GA-2100) are installed in groups every 5 meters to detect the absorption spectra of CH4 and H2 (wavelength range: 1650nm-2200nm), with a sampling frequency of 10Hz and an accuracy of ±0.5%FS.

[0166] In this embodiment, an electrochemical sensor array (Honeywell XNX-C) detects CO concentration (range 0-1000 ppm) and oxygen concentration (range 15%-25%), and the data is transmitted to the edge computing node via the RS-485 bus.

[0167] Specifically, the aforementioned areas where combustible gas accumulates include, but are not limited to: generator sets, transformer rooms, and cable interlayers in power stations.

[0168] Explosion limit dynamic processing module, used for gas explosion limit calculation and risk assessment;

[0169] In this embodiment, the explosion limit range of the combustible gas is calculated in real time. Based on the environmental compensation factor, the lower explosion limit LEL is dynamically corrected using the following logic to obtain the dynamic calculation result of the explosion limit:

[0170]

[0171] Where, V i is the volume fraction of combustible gas i, c i is the concentration of combustible gas i, LEL i is the lower explosion limit of combustible gas i, T is the ambient temperature (°C), P is the air pressure (kPa), and H is the humidity (%RH).

[0172] T0 is the reference temperature (preferably 25°C); α T The temperature correction coefficient ranges from 0.002 to 0.006, preferably 0.004; P0 is standard atmospheric pressure (101.3 kPa); humidity correction coefficient α T The value range is 0.0005-0.0015, preferably 0.001; the value range of the pressure correction index β is 0.2-0.5, preferably 0.3S3, using the prediction model to calculate the risk level of explosion;

[0173] The risk level prediction module is used to establish a trend prediction model for gas concentration changes and define the risk growth rate:

[0174]

[0175] Where c t is the current gas concentration, avg(c t-3→t-1 ) is the average concentration over the past three time points, and Δt is the time interval. The risk growth rate α is calculated independently for each combustible gas, and the final risk level of the system is determined by the largest α value.

[0176] The final comprehensive risk assessment value is:

[0177] R=0.7×LEL+0.3×α

[0178] When the R value reaches or exceeds 0.95, the system automatically triggers an early warning and activates the explosion suppression system.

[0179] A graded explosion suppression execution module is used to perform graded explosion suppression operations;

[0180] The hierarchical explosion suppression execution module includes: a first-level inerting unit, a second-level explosion suppression unit and a third-level active suppression unit. The hierarchical explosion suppression execution module is connected to the risk level prediction module.

[0181] In this embodiment, a first-level explosion suppression operation is performed using a first-level inerting unit;

[0182] In this embodiment, when the concentration of any combustible gas reaches 60% to 80% of its lower explosion limit (LEL), and the corresponding risk growth rate a i When the oxygen concentration is ≥0.02 (unit concentration / minute), the system automatically adjusts the working status of the nitrogen generator according to the real-time monitoring data, injects nitrogen into the target area through the fan, reduces the oxygen concentration to below 18%, and thus suppresses the combustion and explosion chain reaction of combustible gases.

[0183] In this embodiment, the technical parameters for the first-level explosion suppression operation include but are not limited to:

[0184] Nitrogen generator (gas output 30m 3 / min) is sprayed into the generator compartment through an annular distribution pipe (inner diameter 80mm). The nozzle adopts a swirl atomization design with a spray angle of 60° to ensure rapid mixing of nitrogen and air. Oxygen concentration control: PID closed-loop regulation is adopted, with a set value of 18%. When the measured value exceeds 18.5%, the nitrogen flow rate is increased to 35m 3 / min.

[0185] In this embodiment, a secondary explosion suppression unit is used to perform secondary explosion suppression operation;

[0186] In this embodiment, when the concentration of any combustible gas reaches 90% or more of its lower explosion limit and the comprehensive assessment risk value R≥0.85, the system automatically activates the secondary explosion suppression unit and uses perfluorohexanone (C6F 12 O) is mixed with CO2 to spray aerosol, and the generator set is linked to reduce load control.

[0187] In this embodiment, the technical parameters of the secondary explosion suppression operation include but are not limited to:

[0188] The pressure in the 500L perfluorohexanone and CO2 mixing tank is maintained at 2.5MPa, with release controlled by a solenoid valve (response time <10ms). The mixture ratio is 25% perfluorohexanone and 75% CO2, with an injection rate of 8kg / s and a coverage radius of 15m. Interlocking control: When the explosion limit index of the mixed gas reaches the safety threshold, the unit load is reduced. A step signal is sent to the speed regulator via the PLC, reducing the output from 300MW to 150MW in a staged manner within 30 seconds.

[0189] In this embodiment, a three-stage active suppression unit is used to perform a three-stage active suppression operation;

[0190] In this embodiment, when any sensor captures that the concentration of the mixed combustible gas enters the range of the dynamic calculation results of the explosion limit and R≥0.95, the shock wave signal is captured by a high-frequency pressure sensor (response time <1ms), triggering ultrafine water mist (particle size <50μm) + ABC dry powder to perform dual-mode injection to form a physical explosion-proof barrier.

[0191] In this embodiment, the technical parameters of the three-level active explosion suppression operation include but are not limited to:

[0192] Ultrafine water mist nozzle (Lechler 136.134.xx) with working pressure of 8MPa, droplet size Dv90 < 50μm, and coverage area of ​​50m 2 / indivual.

[0193] The ABC dry powder storage tank (capacity 100 kg) is linked with compressed air (0.6 MPa), with an injection rate of 12 kg / s, and is preferentially released upstream in the direction of pressure wave propagation.

[0194] Spatial diversion optimization module, used to guide combustible gas into the inerting area;

[0195] like Figure 3 As shown, in this embodiment, the specific components of the spatial diversion optimization module include but are not limited to:

[0196] Intelligent guide plate array; specifically, the aforementioned intelligent guide plate array is installed on the top of the corridor, which can dynamically adjust the inclination angle (0°~45°) according to the gas concentration distribution, and use the Bernoulli effect to guide the gas into the inerting area. This embodiment combines an adjustable angle mechanical guide structure with a sensor-control system - the adjustable guide plate is organically integrated with a multi-spectral sensor and closed-loop control logic to adjust the guide path in real time according to the combustible gas concentration and flow field changes. Specifically, the guide plate is made of 6061 aluminum alloy, the single plate size is 1200mm×300mm, and the surface is coated with polytetrafluoroethylene to reduce friction resistance.

[0197] The driving mechanism, specifically, adopts a stepper motor (57HS09) in combination with a harmonic reducer. Each guide plate is controlled by a set of driving units, and its structure includes: NEMA series stepper motor; cylindrical harmonic reducer; flexible wheel + wave generator + rigid wheel three-piece structure fixed between the motor output shaft and the guide plate rotating shaft; the stepper motor output is transmitted to the guide plate shaft through the harmonic reducer to achieve high resolution and low backlash precise control.

[0198] In the specific control logic of spatial diversion optimization, based on real-time concentration field data, the posture of the guide plate group is optimized through genetic algorithm, which improves the gas enrichment efficiency by 40%.

[0199] Specifically, the above genetic algorithm optimization strategy is as follows:

[0200] Variables and definitions: n, the number of deflectors; m, the number of critical areas to be protected (such as sensor / heat source areas); θ i ∈[0°, 90°], the adjustable angle of the i-th guide plate; The posture combination of the deflector group (chromosome); The residual gas concentration in region i under the current posture combination; w i , the importance weight of the i-th region.

[0201] Objective function design:

[0202]

[0203] The corresponding fitness function is defined as its reciprocal (or normalized reciprocal):

[0204]

[0205] Genetic algorithm optimization process logic:

[0206] 1. Chromosome encoding: angle θ of each guide plate i Discrete into 8 bits (can represent 256 posture values); the entire individual chromosome is an 8n-bit binary string.

[0207] 2. Initial population generation: randomly initialize k individuals (e.g., k = 50); each individual corresponds to a guide vane angle combination.

[0208] 3. Fitness calculation: Decode each individual → get posture combination Calling approximate models or local CFD predictions Calculate the objective function and fitness

[0209] 4. Genetic operations: Selection: Roulette wheel or tournament selection based on fitness probability; Crossover: Single-point or double-point crossover on chromosomes (exchanging 1-2 random positions); Mutation: Flipping random bits with a probability pm (e.g., 1-5%); Preservation strategy: Preserving the individuals with the best fitness to the next generation (elite strategy);

[0210] 5. Iterative update: Repeat the above steps until the set maximum number of generations Gmax is reached or the fitness converges.

[0211] 6. Decoding output: Output the chromosome with the best fitness, decoded as an angle combination Used to control the deflector attitude.

[0212] In this embodiment, a U-shaped negative pressure gas collecting cavity is used to carry out directional migration of combustible gas:

[0213] In this embodiment, a U-shaped negative pressure gas collecting chamber is set at the bottom of the vertical shaft, and the Venturi effect is used to form a local negative pressure (-500Pa) to directionally migrate the combustible gas.

[0214] Specifically, the throat diameter of the Venturi tube is 200 mm, the inlet expansion angle is 15°, the outlet contraction angle is 30°, and the air flow velocity is increased from 5 m / s to 25 m / s, forming a negative pressure zone of -500 Pa.

[0215] An activated carbon adsorption layer (100mm thick) is set at the bottom of the gas collecting chamber to intercept unburned particulate matter and avoid secondary pollution.

[0216] The ignition source blocking module is used for coordinated control and blocking the ignition source.

[0217] like Figure 4 As shown, in this embodiment, abnormal arc detection is performed;

[0218] Specifically, a broadband current sensor is used to monitor the high-frequency harmonics of the cable. When a transient pulse of 3 MHz or above and an amplitude greater than 5 A is detected, it is determined to be a fault arc. In this embodiment, the bandwidth of the broadband current sensor can be selected, for example, DC-10 MHz;

[0219] The infrared thermal imager (FLIR A8580) scans the surface of the equipment, and the temperature gradient is >15℃ / cm 2 When the warning is triggered.

[0220] In this embodiment, rapid disconnection and explosion suppression are linked:

[0221] Specifically, the graphene solid-state circuit breaker (breaking capacity 100kA) has a built-in IGBT module that cuts off the circuit within 3ms after detecting a fault.

[0222] The circuit breaker signal is transmitted to the explosion suppression controller via optical fiber, and the secondary explosion suppression unit in the corresponding area is triggered with a delay of less than 1ms.

[0223] In addition, in traditional technology, for example, the existing invention patent application document "A Whole-Station Nitrogen Explosion Suppression System" with publication number CN115607875A, the existing system includes a construction module, a simulation calculation module, a detector position confirmation module, a hydrogen concentration confirmation module and a control module. The simulation calculation module simulates and calculates the scenario library to confirm the hydrogen accumulation position and hydrogen leakage parameters; the detector position confirmation module confirms the installation position of the hydrogen concentration detector and the flame detector based on the hydrogen accumulation position and hydrogen leakage parameters; the hydrogen concentration confirmation module obtains the hydrogen concentration detection value of the hydrogen concentration detector; the control module controls the on-site solenoid valve and releases nitrogen to the hydrogen accumulation position based on the hydrogen concentration detection value and the alarm signal of the flame detector. However, the aforementioned existing technology mainly performs inerting and explosion suppression by detecting hydrogen concentration and uniformly releasing nitrogen, without considering the dynamic influence of gas type diversity and environmental factors on explosion limits, and lacks trend identification, hierarchical response mechanism and spatial diffusion path regulation for multi-component gases. Compared with this existing technology, the present invention can achieve multi-dimensional risk suppression. Specifically, traditional explosion suppression systems often rely on a single gas concentration threshold to determine explosion risk, which can easily lead to misjudgments due to variations in gas type and environmental conditions. This invention, based on a multispectral gas sensor array and combined with a dynamically corrected explosion limit calculation model and a risk trend prediction algorithm, enables comprehensive risk assessment of mixed combustible gases, significantly improving monitoring accuracy and safety.

[0224] The existing invention patent application document "A Method and System for Constructing a Power Compartment Fire Extinguishing Model" with publication number CN117744234A, includes constructing a power compartment fire scene simulation module, including a power compartment data acquisition unit, a typical fire scene determination unit, a power compartment physical geometric model construction unit, a fire scene simulation numerical model construction unit, and a simulation result analysis unit. Evaluate the flame sensor detection performance. Construct a power compartment fire extinguishing agent injection dynamic simulation module, including a geometric model construction unit, a parameter setting unit, a spray model establishment unit, a boundary condition setting unit, and a simulation calculation unit. Analyze the confidence of the simulation results. Construct a power compartment fire extinguishing simulation and evaluation model. Set a threshold for the simulation result confidence. When the simulation result confidence is greater than or equal to the threshold, run the power compartment fire extinguishing simulation and evaluation model; when the simulation result confidence is less than the threshold, return to modify the parameters included in the power compartment fire scene simulation model and the power compartment fire extinguishing agent injection dynamic simulation module. However, the aforementioned existing technologies only focus on the simulation and evaluation of post-fire extinguishing models, including numerical simulation of fire scenes, dynamic simulation of injection, and confidence threshold judgment. They lack precise identification of the real-time evolution of multiple components of combustible gases in advance, dynamic explosion limit correction, graded multi-modal linkage explosion suppression, spatial flow field guidance, and pre-isolation of ignition sources. It is difficult to meet the needs of active prevention and control of explosion risks in complex and closed environments. At the same time, traditional explosion suppression systems rely on single concentration threshold monitoring and cannot accurately predict the explosion risk of mixed gases. In addition, the inert medium is placed in a rough manner and the electrical fault blocking is delayed, resulting in low explosion suppression efficiency. In the existing technology, fixed ventilation design is difficult to eliminate gas enrichment at the top of the corridor, and the breaking speed of conventional circuit breakers (>20ms) cannot match the explosion requirements of low ignition energy gases such as H2. Compared with the existing technology, the present invention develops an explosion suppression system that integrates dynamic monitoring, graded inerting and intelligent linkage. Through a high-precision sensor array, dynamic modeling of explosion limits and spatial diversion optimization, it realizes multi-modal collaborative prevention and control and a full-chain prevention and control of dynamic monitoring-intelligent decision-making-graded suppression-spatial optimization, fundamentally improving the safety level of the power station.

[0225] The existing invention patent application document, "A Flow Chemistry Experiment Process Safety Monitoring System and Method," with publication number CN119252358A, targets single gas or chemical reaction parameter (such as flow rate, pressure) monitoring in flow chemistry experiments. The technology relies on fixed thresholds and trend analysis. However, the aforementioned existing solution cannot be directly used to detect and reduce the risk of explosion of mixed combustible gases in pumped storage power plants, nor can it cope with the dynamic evolution of multi-component gases in complex, enclosed environments. It is difficult to perform dynamic explosion limit corrections, and the accuracy of its monitoring and active intervention operations still needs to be improved. Also, the existing invention patent application document, "A Composite System for Online Early Warning and Explosion Suppression of Aviation Kerosene," with publication number CN113466165A, uses fixed threshold triggering for explosion suppression. It targets only a single gas (aviation kerosene vapor) and does not consider the dynamic effects of environmental factors (temperature, humidity) on the explosion limits of mixed gases. Furthermore, it relies on a preset concentration graded response and lacks trend prediction capabilities, resulting in low monitoring accuracy and delayed response. As well as the existing public document "Study on the Explosion Characteristics of Combustible Liquid Vapor and Its Suppression", the aforementioned existing document only targets a single combustible vapor / air system, and sprays inert gas at a static "minimum inerting concentration" at one time, which cannot adapt to the dynamic explosion suppression requirements of multi-component mixed gases with concentration fluctuations under different working conditions. Compared with the aforementioned existing technologies, the present invention optimizes the response speed of the explosion suppression system. Specifically, the present invention adopts a broadband current sensor combined with infrared thermal imaging technology to achieve rapid identification of abnormal arcs, and quickly cuts off the power supply through a graphene solid-state circuit breaker (breaking time <3ms), and at the same time links the explosion suppression system to release the inerting medium in advance, ensuring that the combustion and explosion conditions are blocked within the millisecond response time, greatly reducing the risk of ignition sources.

[0226] The present invention solves the technical problems existing in the prior art of mixed gas explosion risk prediction and monitoring with low accuracy, low explosion suppression efficiency, slow response speed and high operation and maintenance costs.

[0227] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for suppressing explosions in underground caverns of pumped storage power stations, characterized in that: The method comprises: In the explosion monitoring suppression area, a multi-spectral gas sensor array is configured and deployed to obtain the concentration values ​​of each gas component c1, c2, ..., c n ; Introduce environmental compensation factors, according to the concentration values ​​of each gas component c1, c2, ..., c n , calculating the explosion limit of the gas, performing a dynamic correction operation on the explosion limit formula of the gas explosion limit, and obtaining a dynamic calculation result of the explosion limit; Construct and use the gas concentration change trend prediction model, according to the concentration values ​​c1, c2, ..., c n , calculate and establish a trend prediction model for gas concentration changes based on the risk level of explosion to define a risk growth rate, and obtain a comprehensive assessment risk value based on the dynamic calculation result of the explosion limit and the risk growth rate; In the explosion suppression system, a graded explosion suppression execution module is used to perform graded explosion suppression operations according to the comprehensive assessment risk value.

2. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 1, characterized in that: In the explosion monitoring suppression area, a multi-spectral gas sensor array is configured and deployed to obtain the concentration values ​​c1, c2, ..., c n In the step, the explosion monitoring and suppression area includes at least one of the following: a generator set, a transformer room and a cable mezzanine of a pumped storage power station.

3. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 1, characterized in that: The gas concentration change trend prediction model is constructed and used according to the concentration values ​​c1, c2, ..., c n , calculate and establish a gas concentration change trend prediction model based on the risk level of explosion to define the risk growth rate, and in the step of obtaining a comprehensive risk assessment value based on the dynamic calculation result of the explosion limit and the risk growth rate, establish the gas concentration change trend prediction model and define the risk growth rate using the following logic: Where c t is the current gas concentration determined according to the gas concentration change trend prediction model, avg(c t-3→t-1 ) is the average concentration of the past three time points, Δt is the time interval, and the risk growth rate α is calculated independently for each combustible gas. The final risk level of the system is determined by the largest α value; According to the risk growth rate and the dynamic calculation result of the explosion limit, the comprehensive assessment risk value is obtained by using the following calculation formula: R=0.7×LEL+0.3×α When the comprehensive assessment risk value meets the preset trigger conditions, the system automatically triggers an early warning and performs a linkage operation of the explosion suppression system, where LEL represents the lower explosion limit.

4. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 1, characterized in that: The hierarchical explosion suppression execution module includes: a first-level inerting unit, a second-level explosion suppression unit, and a third-level active suppression unit.

5. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 4, characterized in that: The concentration of combustible gas is collected by a sensor. When the concentration of any combustible gas reaches a preset range of its lower explosion limit LEL, and the corresponding risk growth rate meets the preset conditions, and the gas concentration change trend prediction model shows that the gas risk is increasing, the first-level inerting unit is activated, and according to the comprehensive assessment risk value, the working state of the nitrogen generator is adjusted to suppress the combustion and explosion chain reaction of the gas, thereby completing the first-level explosion suppression operation.

6. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 4, characterized in that: When the preset conditions are met, the secondary explosion suppression unit is activated, and according to the dynamic calculation result of the explosion limit, a mixed gas mist of perfluorohexanone C6F12O and CO2 is sprayed through the pre-buried pipeline to suppress the explosion.

7. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 6, characterized in that: The preset conditions include: using a sensor to collect the concentration of combustible gas, any of the combustible gas concentrations reaches a preset proportion range of the lower explosion limit of the combustible gas, and the comprehensive assessment risk value is not less than a preset threshold.

8. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 4, characterized in that: When any sensor captures that the concentration of mixed combustible gas enters the range of the dynamic calculation result of the explosion limit, and the comprehensive assessment risk value R is not less than the preset threshold, the three-level active suppression unit is activated, and the deflagration shock wave signal is captured in real time through the high-frequency pressure sensor, triggering the dual-mode injection of ultrafine water mist and ABC dry powder.

9. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 1, characterized in that: Also includes: The combustible gas is guided into the inerting zone by using a spatial flow diversion optimization module, wherein the spatial flow diversion optimization module includes: An intelligent deflector array dynamically adjusts the inclination angle according to the gas concentration distribution, using the Bernoulli effect to guide the gas into the inerting zone; The negative pressure gas collecting chamber is used to generate local negative pressure through the Venturi accelerator to carry out directional migration of combustible gas.

10. The method for suppressing explosion in underground caverns of a pumped storage power station according to claim 1, characterized in that: Also includes: The ignition source blocking module is used for coordinated control to block the ignition source, a broadband current sensor is used to monitor the equipment discharge signal, and infrared thermal imaging is used to identify abnormal arcs. When it is detected that the discharge energy is greater than the preset threshold, the graphene solid-state circuit breaker is triggered, and the secondary explosion suppression unit in the partition is linked to pre-release the inerting medium.

11. Pumped storage power station underground cavern explosion suppression system, characterized by: The system comprises: Multispectral gas sensing module is used to configure and deploy a multispectral gas sensor array in the explosion monitoring suppression area to obtain the concentration values ​​of each gas component c1, c2, ..., c n ; The explosion limit dynamic processing module is used to introduce the environmental compensation factor according to the concentration values ​​of each gas component c1, c2, ..., c n , calculating the gas explosion limit, performing a dynamic correction operation on the explosion limit formula of the gas explosion limit, and obtaining a dynamic calculation result of the explosion limit, wherein the explosion limit dynamic processing module is connected to the multi-spectral gas sensing module, and the explosion limit dynamic processing module is connected to the multi-spectral gas sensing module; The risk level prediction module is used to build and use the gas concentration change trend prediction model, according to the concentration values ​​of each gas component c1, c2, ..., c n , calculate the risk level of explosion, establish a trend prediction model for gas concentration changes to define the risk growth rate, and obtain a comprehensive assessment risk value based on the dynamic calculation results of the explosion limit and the risk growth rate. The risk level prediction module is connected to the multi-spectral gas sensing module; The graded explosion suppression execution module is used to perform graded explosion suppression operations according to the risk level, wherein the graded explosion suppression execution module includes: a first-level inerting unit, a second-level explosion suppression unit and a third-level active suppression unit, and the graded explosion suppression execution module is connected to the risk level prediction module.

12. The underground cavern explosion suppression system for a pumped storage power station according to claim 11, characterized in that: In the multi-spectral gas sensing module, the explosion monitoring and suppression area includes at least one of the following: a generator set, a transformer room, and a cable mezzanine of a pumped storage power station.

13. The explosion suppression system for underground caverns of a pumped storage power station according to claim 11, characterized in that: The risk level prediction module includes: The risk growth rate definition module is used to establish the gas concentration change trend prediction model and define the risk growth rate using the following logic: Where c t is the current gas concentration, avg(c t-3→t-1 ) is the average concentration of the past three time points, Δt is the time interval, and the risk growth rate α is calculated independently for each combustible gas. The final risk level of the system is determined by the largest α value; The risk assessment module is used to obtain the comprehensive assessment risk value according to the risk growth rate and the dynamic calculation result of the explosion limit using the following calculation formula: R=0.7×LEL+0.3×α The risk assessment module is connected to the risk growth rate definition module; The explosion suppression trigger module is used to automatically trigger an early warning when the comprehensive assessment risk value meets the preset trigger condition, and perform a linkage operation of the explosion suppression system. The explosion suppression trigger module is connected to the assessment risk module.

14. The explosion suppression system for underground caverns of a pumped storage power station according to claim 11, characterized in that: The hierarchical explosion suppression execution module includes: a first-level inerting unit, a second-level explosion suppression unit and a third-level active suppression unit.

15. The explosion suppression system for underground caverns of a pumped storage power station according to claim 14, characterized in that: The first-level inerting unit is used to activate the first-level inerting unit when the concentration of any combustible gas reaches a preset range of its lower explosion limit LEL, the corresponding risk growth rate meets the preset conditions, and the gas concentration change trend prediction model shows that the gas risk is increasing. According to the comprehensive assessment risk value, the working state of the nitrogen generator is adjusted to suppress the gas combustion and explosion chain reaction, thereby completing the first-level explosion suppression operation.

16. The explosion suppression system for underground caverns of a pumped storage power station according to claim 14, characterized in that: The secondary explosion suppression unit is used to activate the secondary explosion suppression unit when preset conditions are met, and to suppress explosion by spraying a mixed gas mist of perfluorohexanone C6F12O and CO2 through a pre-buried pipeline according to the dynamic calculation result of the explosion limit.

17. The explosion suppression system for underground caverns of a pumped storage power station according to claim 16, characterized in that: The preset conditions include: the concentration of any combustible gas reaches a preset proportion range of the lower explosion limit of the combustible gas, and the comprehensive assessment risk value is not less than a preset threshold.

18. The explosion suppression system for underground caverns of a pumped storage power station according to claim 14, characterized in that: The three-stage active suppression unit is used to start the three-stage active suppression unit when any sensor captures that the concentration of the mixed combustible gas enters the range of the dynamic calculation result of the explosion limit and the comprehensive assessment risk value R is not less than the preset threshold. The high-frequency pressure sensor is used to capture the deflagration shock wave signal in real time and trigger the dual-mode injection of ultrafine water mist and ABC dry powder.

19. The underground cavern explosion suppression system for a pumped storage power station according to claim 11, characterized in that: Also includes: Spatial diversion optimization module, used to guide combustible gas into the inerting area; The spatial diversion optimization module includes: An intelligent deflector array dynamically adjusts the inclination angle according to the gas concentration distribution, using the Bernoulli effect to guide the gas into the inerting zone; The negative pressure gas collecting chamber is used to generate local negative pressure through the Venturi accelerator to carry out directional migration of combustible gas.

20. The underground cavern explosion suppression system for a pumped storage power station according to claim 11, characterized in that: Also includes: The ignition source blocking module is used for coordinated control and blocking of ignition sources. It uses a broadband current sensor to monitor the equipment discharge signal and combines infrared thermal imaging to identify abnormal arcs. When it is detected that the discharge energy is greater than the preset threshold, the graphene solid-state circuit breaker is triggered, and the secondary explosion suppression unit in the partition is linked to pre-release the inerting medium.

Images