CN106703887B - Secondary gas explosion determination method during mine heat power disaster assistance - Google Patents

Abstract

The invention discloses a method for judging a secondary gas explosion in the rescue process of a mine thermodynamic disaster, which comprises the steps of: 1. determining the location of the secondary gas explosion; 2. estimating the time when the secondary gas explosion occurs in the monitored area. As follows: 201. Obtain the environmental parameters of the monitored area; 202. Determine whether the monitored area is an area where a high-concentration gas explosion occurs; 203. Estimation of the time and probability of a high-concentration gas explosion; 204. The time when a low-concentration gas explosion occurs and probability estimation; 3. Estimate the time of secondary gas explosion in the monitored area; 4. Display and real-time storage of secondary gas explosion judgment results. The invention is novel in design and can determine the three key indicators of the time, probability and location of secondary gas explosions underground in coal mines during the rescue process after a thermal power disaster, and can provide theoretical reference and guidance for command and decision-making of thermal power disaster rescue.

Description

Judgment method of secondary gas explosion during mine thermal power disaster rescue

technical field

The invention belongs to the technical field of mine thermodynamic disaster rescue, and in particular relates to a secondary gas explosion determination method in the mine thermodynamic disaster rescue process.

Background technique

The evolution mechanism of mine fires and gas explosions in thermal and dynamic disasters in coal mines is extremely complex, and a variety of secondary disasters may occur during the rescue process, such as roadway roof fall, high temperature heat damage, high concentration smoke, open flame fires, gas and coal dust explosions , disordered wind flow, large amounts of toxic and harmful gases, damage to the ventilation system, etc. As the implementers of mine rescue work and the frontline personnel in danger of disaster relief, the personal protective equipment of rescuers usually only protects them from the threat of toxic and harmful gases, but has little protection against gas explosions. During the rescue process, a sudden gas explosion may lead to the death of rescue personnel entering the disaster area, which seriously threatens the life safety of rescue personnel and affects the progress and success of rescue. The scientific and timely formulation of mine thermal power disaster rescue command decision-making has important theoretical guiding significance for ensuring the life safety of rescuers. However, most of the existing research focuses on the mechanism and control technology of the primary gas explosion, and there are relatively few studies on the mechanism and characteristics of the gas explosion during the rescue process. Due to the thermal and dynamic effects of the disaster, the ventilation of the underground disaster area is often in a disordered state after the thermodynamic disaster, and the disaster situation is extremely vague and difficult to predict. The research on the mechanism and characteristics of gas explosions in the process of thermal dynamic disaster rescue has made slow progress, and it is difficult to scientifically and effectively guide the command and decision-making work of thermal dynamic disaster rescue. Therefore, there is currently a lack of a secondary gas explosion determination method in the mine thermodynamic disaster rescue process. The three key indicators of gas explosion occurrence time, probability and location have important theoretical guiding significance for the command and decision-making of mine thermodynamic disaster rescue.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for judging secondary gas explosions in the mine thermal power disaster rescue process in view of the above-mentioned deficiencies in the prior art. The three key indicators of the time, probability and location of the secondary gas explosion can provide theoretical reference and guidance for the command and decision-making of thermal power disaster rescue.

In order to solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for judging secondary gas explosions in the process of mine thermal power disaster rescue, which is characterized in that the method includes the following steps:

Step 1. Determine the location of the secondary gas explosion: install regional monitoring nodes at multiple key locations in the mine to collect temperature parameters in the corresponding areas and transmit the temperature parameters in this area to the control computer installed in the monitoring room in real time. The keyboard input module sets the temperature parameter threshold, uses the control computer to calibrate the key position that reaches the temperature parameter threshold, and predicts the location where the secondary gas explosion occurs;

The regional monitoring node includes a regional controller and a clock circuit and a communication module connected to the regional controller. The input terminal of the regional controller is connected with a temperature sensor, a wind speed sensor, a gas sensor, and is used to collect gas concentration and A gas monitor for gas flow and an oxygen monitor for collecting oxygen concentration and oxygen flow in the monitored area;

Step 2. Estimate the time of the secondary gas explosion in the monitored area, the process is as follows:

Step 201, obtaining the environmental parameters of the monitored area: monitoring the ventilation status of the monitored area through the wind speed sensor, and monitoring the gas content and oxygen content of the monitored area through the gas monitor and the oxygen monitor respectively;

Step 202. Determine whether the monitored area is an area where high-concentration gas explosions occur: set the monitoring parameter change time threshold through the area controller, and judge the monitored area after the disaster according to the environmental parameters obtained in step 201 and the environmental parameter change time recorded by the clock circuit. Whether the area is a high-concentration gas explosion area, when the gas content and oxygen content in the monitored area monitored by the gas monitor and oxygen monitor reach the limit of gas explosion after the disaster, the time threshold for changing the monitoring parameters is less than the monitoring parameter change time threshold, indicating that the monitored area is a high-concentration gas explosion area. Concentration gas explosion area, go to step 203; otherwise, go to step 204;

Step 203, estimate the time when the high-concentration gas explosion occurs, the process is as follows:

Step 2031, according to the formula By solving the differential equation, the time t ₁ and the time t ₂ for the change of the oxygen concentration and the change of the methane concentration in the high-concentration gas explosion area can be obtained, where, V is the volume of the high-concentration gas explosion area, q ₁ is the flow rate of the mixed gas flowing into the high-concentration gas explosion area, q ₂ is the flow rate of the mixed gas flowing out of the high-concentration gas explosion area, and c ₁ is the oxygen flow into the high-concentration gas explosion area c ₂ is the concentration of methane flowing into the high-concentration gas explosion area, c ₀₁ is the initial value of oxygen concentration when the initial condition t ₁ =0, is the target value of the oxygen concentration to be achieved, c ₀₂ is the initial value of the methane concentration when the initial condition t ₂ =0, is the target value to be achieved by the methane concentration;

Step 2032, according to the formula Calculate the time T ₁ for the oxygen concentration to become 12% in the post-disaster high-concentration gas explosion area, the time T 21 for the gas concentration to reach the lower explosion limit of 5%, and the time T ₂₂ for the gas concentration to reach the upper explosion limit of ₁₆ %;

Step 2033, estimate the time when the high-concentration gas explosion occurs: when the oxygen concentration becomes 12% in step 2032, the elapsed time T ₁ >T ₂₂ , the high-concentration gas explosion does not occur; when the oxygen concentration becomes 12% in step 2032 When the elapsed time T ₂₁ ≤ T ₁ ≤ T ₂₂ , the high-concentration gas explosion occurs at a time t that satisfies: T ₁ + t ₃ ≤ t ≤ T ₂₂ + t ₃ , where t ₃ is the gas that reaches the gas explosion limit Time to the fire source; when the time T ₁ <T ₂₁ for the oxygen concentration to become 12% in step 2032, the time t for the explosion of high-concentration gas satisfies: T ₂₁ +t ₃ ≤t≤T ₂₂ +t ₃ ;

Step 204, estimate the time when the low-concentration gas explosion occurs, the process is as follows:

Step 2041, according to the formula By solving the differential equation, the time t' ₁ and the time t' ₂ for the change of the oxygen concentration and the change of the methane concentration in the low-concentration gas explosion area can be obtained, where, V' is the volume of the low-concentration gas explosion area, q' ₁ is the flow rate of the mixed gas flowing into the low-concentration gas explosion area, q' ₂ is the flow rate of the mixed gas flowing out of the low-concentration gas explosion area, c' ₁ is the flow rate of the low-concentration gas explosion area The concentration of oxygen in the explosion area, c' ₂ is the concentration of methane flowing into the low-concentration gas explosion area, c' ₀₁ is the initial value of oxygen concentration when the initial condition t' ₁ =0, c' ₀₂ is the initial condition t' ₂ = 0, the initial value of methane concentration;

Step 2042, according to the formula Calculate the time T' ₁ for the oxygen concentration in the low-concentration gas explosion area to become 12% after the disaster, the time T' ₂₁ for the gas concentration to reach 5% of the lower explosion limit, and the time T' ₂₂ for the gas concentration to reach 16% of the upper limit of the explosion ;

Step 2043. Estimate the occurrence time of the low-concentration gas explosion: when the time T' ₁ >T' ₂₂ when the oxygen concentration becomes 12% in step 2042, the occurrence time t' of the low-concentration gas explosion satisfies: T' ₂₁ + t' ₃ ≤ t' ≤ T' ₂₂ + t'₃; when the time T' ₂₁ ≤ T' ₁ ≤ T' ₂₂ elapsed when the oxygen concentration becomes 12% in step 2042, the time t when the low-concentration gas explosion occurs 'Satisfy: T' ₂₁ +t' ₃ ≤ t' ≤ T' ₁ + t'₃; when the time T' ₁ <T' ₂₁ elapsed when the oxygen concentration becomes 12% in step 2042, the low-concentration gas explosion will not Occurrence, wherein, t' ₃ is the time when the gas reaching the limit of gas explosion encounters the fire source;

Step 3. Estimate the probability of secondary gas explosion in the monitored area: According to the gas explosion accident tree analysis method, the probability of gas explosion P=P ₁ ×P ₂ ×P ₃ , where P ₁ is the gas concentration in the monitored area after the disaster The probability of reaching the gas explosion limit and P ₁ satisfies according to the Kovad explosion triangle: P ₁ =P _1i , i=1~4 and P ₁₁ =1>P ₁₃ >P ₁₂ >P ₁₄ =0, P ₁₁ is the gas concentration Probability of the gas explosion limit when the gas concentration is between 5% and 16% and the oxygen concentration is greater than 12%, P ₁₂ is the probability of the gas explosion limit when the gas concentration is between 5% and 16% and the oxygen concentration is less than 12%, P ₁₃ is the probability of the gas explosion limit when the gas concentration is greater than 16% and the oxygen concentration is less than 12%, and P ₁₄ is the probability of the gas explosion limit when the gas concentration is less than 5%. Both the probability P ₁₂ and the probability P ₁₃ are estimated by the expert scoring method Probability value, P ₂ is the probability that there is a fire source that can cause a gas explosion in the monitored area after the disaster, and P ₃ is the probability that the gas that reaches the gas explosion limit in the monitored area after the disaster meets the fire source;

Step 4. Display and real-time storage of secondary gas explosion determination results: Simultaneously monitor the time and probability of secondary gas explosions at the key positions in the underground through multiple regional monitoring nodes, and transmit the determination results at corresponding positions to the The control computer can view the judgment results in real time through the display, and save the judgment results in real time through the memory.

The above method for judging secondary gas explosions in the mine thermodynamic disaster rescue process is characterized in that: the key positions mentioned in step 1 and step 4 include the air inlet tunnel of the working face, the return air tunnel of the working face, the middle part of the working face, the The return air corner, the main air inlet belt roadway, the area affected by high-temperature smoke flow after the previous mine thermodynamic disaster occurred, and the area affected by abnormal gas gushing near live electrical appliances.

The method for judging the secondary gas explosion in the mine thermodynamic disaster rescue process described above is characterized in that: in step 3, the probability Among them, N is the number of experts, p _12j is the probability of the gas explosion limit given by the jth expert when the gas concentration is between 5% and 16% and the oxygen concentration is less than 12%, δ _j is the weight corresponding to p _12j and p _13j is the probability of the gas explosion limit given by the jth expert when the gas concentration is greater than 16% and the oxygen concentration is less than 12%, δ' _j is the weight corresponding to p _13j and

The method for judging the secondary gas explosion in the mine thermodynamic disaster rescue process described above is characterized in that: in step 3, the probability Among them, the probability P ₂₁ is the probability that the fire source in the monitored area after the disaster is a persistent fire source and P ₂₁ =1, and the probability P ₂₂ is the probability that the fire source in the monitored area after the disaster is a transient fire source and 0≤P ₂₂ ≤1.

The above-mentioned method for judging secondary gas explosions in the rescue process of mine thermodynamic disasters is characterized in that the probability P ₃ =1 in Step 3.

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

1. The present invention installs regional monitoring nodes at multiple key positions in the mine, and simultaneously monitors the time and probability of secondary gas explosions at multiple key positions, and the control computer can simultaneously process the data collected by multiple regional monitoring nodes , to achieve the purpose of monitoring the entire mine at the same time, which is convenient for popularization and use.

2. Combining the characteristics of mine thermodynamic disasters, underground disaster areas and gas explosions, the present invention proposes methods for determining the time range of gas explosions after high-concentration gas explosions and low-concentration gas explosions, with high accuracy.

3. The determination method of the present invention can determine the three key indicators of the time, probability and location of the secondary gas explosion in the mine during the rescue process after the thermal power disaster, which is of great significance for ensuring the life safety of rescuers, good feasibility and practicality Strong, good prospects for popularization and application.

In summary, the present invention is novel and reasonable in design, novel in design, and can determine the three key indicators of time, probability and location of secondary gas explosions in coal mines during the rescue process after a thermal power disaster, which can be used as a command for thermal power disaster rescue. Decision-making provides theoretical reference and guidance.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is the circuit schematic diagram of the secondary gas explosion judging equipment adopted in the present invention. .

Fig. 2 is a schematic block diagram of the circuit of the regional monitoring node of the present invention.

Fig. 3 is a flow chart of the method for judging the secondary gas explosion of the present invention.

Explanation of reference signs:

1—area monitoring node; 1-1—temperature sensor; 1-2—wind speed sensor;

1-3—gas monitor; 1-4—oxygen monitor; 1-5—clock circuit;

1-6—area controller; 1-7—communication module; 1-8—gas sensor;

2—keyboard input module; 3—control computer; 4—monitor;

5—Memory.

Detailed ways

As shown in Figure 1, the secondary gas explosion judging method in the mine thermodynamic disaster rescue process of the present invention comprises the following steps:

Step 1. Determine the location of the secondary gas explosion: install regional monitoring nodes 1 at multiple key locations in the mine to collect temperature parameters in the corresponding areas and transmit the temperature parameters in this area to the control computer 3 installed in the monitoring room in real time , setting the temperature parameter threshold through the keyboard input module 2, using the control computer 3 to calibrate the key position that reaches the temperature parameter threshold, and predicting the location where the secondary gas explosion occurs;

The regional monitoring node 1 includes a regional controller 1-6, a clock circuit 1-5 and a communication module 1-7 connected to the regional controller 1-6, and the input terminal of the regional controller 1-6 is connected with a temperature sensor 1 -1. Wind speed sensor 1-2, gas sensor 1-8, gas monitor 1-3 for collecting gas concentration and gas flow in the monitored area, and oxygen monitoring for collecting oxygen concentration and oxygen flow in the monitored area instrument 1-4;

In this embodiment, the key positions include the air inlet roadway of the working face, the air return roadway of the working face, the middle part of the working face, the return air corner of the working face, the main air inlet belt roadway, and the high-temperature smoke flow after the previous mine thermodynamic disaster occurred. Affected areas and areas close to live electrical appliances and affected by abnormal gas gushing.

A gas explosion must have a fire source, so the location of a fire source that can cause a gas explosion can be regarded as the location where a gas explosion occurs again. In actual mine production, if the fire source that caused the previous mine thermodynamic disaster is a continuous fire source , then the fire source must exist, and the energy is enough to cause a gas explosion; if the previous mine thermodynamic disaster was an instantaneous fire source, then the previous mine thermodynamic disaster may ignite the disaster-causing point in the monitoring area after the disaster or the center of the disaster area Combustibles within a certain range become the ignition source of gas explosions; secondly, after the previous mine thermodynamic disaster occurred, the high-temperature smoke spread to the area, such as the high-risk areas and blind alleys near the monitored area after the disaster. If the monitored area after the disaster or In the ventilation network connected to the post-disaster monitoring area, there is a high-concentration gas pool. When the high-temperature smoke in the post-disaster monitoring area spreads to such areas, it still has sufficient temperature. In addition, the high-temperature smoke may mix with fresh air, resulting in such areas. If the gas, oxygen concentration and fire source all meet the gas explosion conditions, the gas explosion will be triggered; in addition, if there is abnormal gas gushing out in the monitored area after the disaster, a large amount of gas gushes out instantly, causing the gas in the disaster area to reach the explosion limit. If there are live electrical appliances in these areas, gas explosions may be caused by electrical sparks, posing a threat to the life safety of rescuers entering the monitored area after the disaster.

Step 2. Estimate the time of the secondary gas explosion in the monitored area, the process is as follows:

Step 201, obtain the environmental parameters of the monitored area: monitor the ventilation status of the monitored area through the wind speed sensor 1-2, monitor the gas content and oxygen content of the monitored area through the gas monitor 1-3 and the oxygen monitor 1-4 respectively ;

It should be noted that the monitored area is any one of the key positions, and an area monitoring node 1 is installed at any key position to estimate the time and probability of a secondary gas explosion in the monitored area. The methods for estimating the time and probability of secondary gas explosions in the monitored area are the same, and the control computer 3 can simultaneously monitor the judgment results of secondary gas explosions in multiple key locations underground during the rescue process of mine thermodynamic disasters.

Step 202, judging whether the monitored area is an area where a high-concentration gas explosion occurs: set the monitoring parameter change time threshold through the area controller 1-6, and change according to the environmental parameters obtained in step 201 and the environmental parameters recorded by the clock circuit 1-5 Time, to determine whether the monitored area after the disaster is a high-concentration gas explosion area, when the gas content and oxygen content of the monitored area after the disaster are monitored by the gas monitor 1-3 and the oxygen monitor 1-4, the time is less than the monitoring parameters When the time threshold is changed, it means that the monitored area is a high-concentration gas explosion area, and step 203 is executed; otherwise, step 204 is executed;

It should be noted that the high-concentration gas explosion refers to the rapid increase of gas concentration and oxygen concentration in the monitored area after the previous mine thermodynamic disaster occurred, and the gas concentration and oxygen concentration both increased; the low-concentration gas explosion refers to the previous After a mine thermodynamic disaster occurred, the gas concentration in the monitored area was extremely low, 5% lower than the explosion limit of the gas concentration, and the corresponding oxygen concentration was high, with the oxygen concentration higher than 12%, and the gas concentration was slowly increasing. It is in a slowly decreasing state, and the mine environment can be collected by wind speed sensor 1-2, temperature sensor 1-1 and gas sensor 1-8, providing a reference for judging whether the monitored area is an area where high-concentration gas explosions occur.

Step 203, estimate the time when the high-concentration gas explosion occurs, the process is as follows:

Step 2031, according to the formula By solving the differential equation, the time t ₁ and the time t ₂ for the change of the oxygen concentration and the change of the methane concentration in the high-concentration gas explosion area can be obtained, where, V is the volume of the high-concentration gas explosion area, q ₁ is the flow rate of the mixed gas flowing into the high-concentration gas explosion area, q ₂ is the flow rate of the mixed gas flowing out of the high-concentration gas explosion area, and c ₁ is the oxygen flow into the high-concentration gas explosion area c ₂ is the concentration of methane flowing into the high-concentration gas explosion area, c ₀₁ is the initial value of oxygen concentration when the initial condition t ₁ =0, is the target value of the oxygen concentration to be achieved, c ₀₂ is the initial value of the methane concentration when the initial condition t ₂ =0, is the target value to be achieved by the methane concentration;

In actual production, the time _t1 and the time _t2 experienced by the oxygen concentration change in the high-concentration gas explosion area are both recorded by the clock circuit 1-5 in the area monitoring node 1 in the monitored area. The gas explosion area is any one of the key positions, the volume V of the high-concentration gas explosion area is an empirical value, the flow _q1 of the mixed gas flowing into the high-concentration gas explosion area and the flow rate of the mixed gas flowing out of the high-concentration gas explosion area q ₂ is measured by gas sensors 1-8, the oxygen concentration c ₁ flowing into the high-concentration gas explosion area, the initial value c ₀₁ of the oxygen concentration when the initial condition t ₁ = 0, and the target value to be achieved by the oxygen concentration All measured by the oxygen monitor 1-4, the methane concentration c ₂ flowing into the high-concentration gas explosion area, the initial value c ₀₂ of the methane concentration when the initial condition t ₂ =0, and the target value of the methane concentration to be achieved All measured by methane monitor 1-3.

Step 2032, according to the formula Calculate the time T ₁ for the oxygen concentration to become 12% in the post-disaster high-concentration gas explosion area, the time T 21 for the gas concentration to reach the lower explosion limit of 5%, and the time T ₂₂ for the gas concentration to reach the upper explosion limit of ₁₆ %;

Step 2033, estimate the time when the high-concentration gas explosion occurs: when the oxygen concentration becomes 12% in step 2032, the elapsed time T ₁ >T ₂₂ , the high-concentration gas explosion does not occur; when the oxygen concentration becomes 12% in step 2032 When the elapsed time T ₂₁ ≤ T ₁ ≤ T ₂₂ , the high-concentration gas explosion occurs at a time t that satisfies: T ₁ + t ₃ ≤ t ≤ T ₂₂ + t ₃ , where t ₃ is the gas that reaches the gas explosion limit Time to the fire source; when the time T ₁ <T ₂₁ for the oxygen concentration to become 12% in step 2032, the time t for the explosion of high-concentration gas satisfies: T ₂₁ +t ₃ ≤t≤T ₂₂ +t ₃ ;

In actual production, the temperature threshold of the temperature sensor 1-1 and the temperature change rate threshold of the high-concentration gas explosion zone are set by the zone controller 1-6 in the zone monitoring node 1 in the high-concentration gas explosion zone, and the gas that reaches the gas explosion limit The time _t3 when encountering the fire source is measured by the recording time of the clock circuit 1-5 during the temperature data change process of the temperature sensor 1-1. When the temperature data collected by the temperature sensor 1-1 in the high-concentration gas explosion area increases slowly The time when the gas that reaches the gas explosion limit encounters the fire source is determined by the temperature threshold of the temperature sensor 1-1. When the temperature threshold of the temperature sensor 1-1 is reached, the rescue team who enters the monitoring area after the disaster will be reminded to pay attention to safety; When the temperature data collected by the temperature sensor 1-1 in the high-concentration gas explosion area increases rapidly, the time when the gas reaching the limit of the gas explosion encounters the fire source is determined by the temperature change rate threshold of the temperature sensor 1-1, and it should be reminded The ambulance team members who entered the monitoring area immediately carried out concealed self-rescue to avoid the harm caused by the secondary gas explosion.

Step 204, estimate the time when the low-concentration gas explosion occurs, the process is as follows:

Step 2041, according to the formula By solving the differential equation, the time t' ₁ and the time t' ₂ for the change of the oxygen concentration and the change of the methane concentration in the low-concentration gas explosion area can be obtained, where, V' is the volume of the low-concentration gas explosion area, q' ₁ is the flow rate of the mixed gas flowing into the low-concentration gas explosion area, q' ₂ is the flow rate of the mixed gas flowing out of the low-concentration gas explosion area, c' ₁ is the flow rate of the low-concentration gas explosion area The concentration of oxygen in the explosion area, c' ₂ is the concentration of methane flowing into the low-concentration gas explosion area, c' ₀₁ is the initial value of oxygen concentration when the initial condition t' ₁ =0, c' ₀₂ is the initial condition t' ₂ = 0, the initial value of methane concentration;

In actual production, the time _t'1 and the time _t'2 of the oxygen concentration change in the low-concentration gas explosion area are all recorded by the clock circuit 1-5 in the area monitoring node 1 in the monitored area, The low-concentration gas explosion area is any one of the key positions, the volume V of the low-concentration gas explosion area is an empirical value, and the flow q' ₁ of the mixed gas flowing into the low-concentration gas explosion area is mixed The gas flow q' ₂ is measured by gas sensors 1-8, the concentration c' ₁ of oxygen flowing into the low-concentration gas explosion area and the initial value c' ₀₁ of the oxygen concentration when the initial condition t' ₁ = 0 are all determined by oxygen As measured by the monitor 1-4, the methane concentration c' ₂ flowing into the low-concentration gas explosion area and the initial value c' ₀₂ of the methane concentration when the initial condition t' ₂ =0 are both measured by the methane monitor 1-3.

Step 2042, according to the formula Calculate the time T' ₁ for the oxygen concentration in the low-concentration gas explosion area to become 12% after the disaster, the time T' ₂₁ for the gas concentration to reach 5% of the lower explosion limit, and the time T' ₂₂ for the gas concentration to reach 16% of the upper limit of the explosion ;

Step 2043. Estimate the occurrence time of the low-concentration gas explosion: when the time T' ₁ >T' ₂₂ when the oxygen concentration becomes 12% in step 2042, the occurrence time t' of the low-concentration gas explosion satisfies: T' ₂₁ + t' ₃ ≤ t' ≤ T' ₂₂ + t'₃; when the time T' ₂₁ ≤ T' ₁ ≤ T' ₂₂ elapsed when the oxygen concentration becomes 12% in step 2042, the time t when the low-concentration gas explosion occurs 'Satisfy: T' ₂₁ +t' ₃ ≤ t' ≤ T' ₁ + t'₃; when the time T' ₁ <T' ₂₁ elapsed when the oxygen concentration becomes 12% in step 2042, the low-concentration gas explosion will not Occurrence, wherein, t' ₃ is the time when the gas reaching the limit of gas explosion encounters the fire source;

In actual production, the temperature threshold of the temperature sensor 1-1 and the temperature change rate threshold of the low concentration gas explosion area are set by the area controller 1-6 in the area monitoring node 1 in the low concentration gas explosion area, and the gas that reaches the gas explosion limit The time t'3 _of encountering the fire source is measured by the recording time of the clock circuit 1-5 during the temperature data change process of the temperature sensor 1-1. When the temperature data collected by the temperature sensor 1-1 in the low concentration gas explosion area increases at When it is slow, the time when the gas that reaches the limit of gas explosion encounters the fire source is determined by the temperature threshold of the temperature sensor 1-1. When the temperature threshold of the temperature sensor 1-1 is reached, the rescue team who enters the monitoring area after the disaster will be reminded in time to pay attention to safety; When the temperature data collected by the temperature sensor 1-1 in the low-concentration gas explosion area increases rapidly, the time when the gas that reaches the gas explosion limit encounters the fire source is determined by the temperature change rate threshold of the temperature sensor 1-1. Remind the rescue team who entered the monitoring area after the disaster to carry out concealed self-rescue immediately to avoid the harm caused by the secondary gas explosion.

Step 3. Estimate the probability of secondary gas explosion in the monitored area: According to the gas explosion accident tree analysis method, the probability of gas explosion P=P ₁ ×P ₂ ×P ₃ , where P ₁ is the gas concentration in the monitored area after the disaster The probability of reaching the gas explosion limit and P ₁ satisfies according to the Kovad explosion triangle: P ₁ =P _1i , i=1~4 and P ₁₁ =1>P ₁₃ >P ₁₂ >P ₁₄ =0, P ₁₁ is the gas concentration Probability of the gas explosion limit when the gas concentration is between 5% and 16% and the oxygen concentration is greater than 12%, P ₁₂ is the probability of the gas explosion limit when the gas concentration is between 5% and 16% and the oxygen concentration is less than 12%, P ₁₃ is the probability of the gas explosion limit when the gas concentration is greater than 16% and the oxygen concentration is less than 12%, and P ₁₄ is the probability of the gas explosion limit when the gas concentration is less than 5%. Both the probability P ₁₂ and the probability P ₁₃ are estimated by the expert scoring method Probability value, P ₂ is the probability that there is a fire source that can cause a gas explosion in the monitored area after the disaster, and P ₃ is the probability that the gas that reaches the gas explosion limit in the monitored area after the disaster meets the fire source;

In this embodiment, the probability in step three Among them, N is the number of experts, p _12j is the probability of the gas explosion limit given by the jth expert when the gas concentration is between 5% and 16% and the oxygen concentration is less than 12%, δ _j is the weight corresponding to p _12j and p _13j is the probability of the gas explosion limit given by the jth expert when the gas concentration is greater than 16% and the oxygen concentration is less than 12%, δ _j ' is the weight corresponding to p _13j and

In this embodiment, the probability in step three Among them, the probability P ₂₁ is the probability that the fire source in the monitored area after the disaster is a persistent fire source and P ₂₁ =1, and the probability P ₂₂ is the probability that the fire source in the monitored area after the disaster is a transient fire source and 0≤P ₂₂ ≤1.

In actual production, a persistent fire source refers to an fire source that exists for a long time and can trigger the energy required for a gas explosion after the first thermodynamic disaster is triggered, such as an open flame fire, etc. Disasters caused by such fire sources can be regarded as The probability of the secondary fire source is 1, that is, the probability P ₂₁ =1; the instantaneous fire source refers to the fire source that disappears instantaneously after the first thermodynamic disaster is triggered, such as an electric spark.

In this embodiment, the probability P ₃ =1 in step three.

In actual production, due to the complexity and ambiguity of thermodynamic disasters, rescuers often cannot accurately grasp the real disaster information. Therefore, it is impossible to judge the probability of explosive gas mixture and fire source. In actual rescue work, from Considering the maximum safety, we believe that it will happen inevitably, that is, the probability P ₃ =1. In consideration of the life safety of the on-site rescuers, in order to prevent further expansion of the accident, during rescue, we generally believe that as long as the gas in the disaster area reaches the explosion limit, it will A gas explosion will definitely occur, that is, the probability of gas explosion P=P ₁ .

Step 4. Display and real-time storage of secondary gas explosion determination results: Simultaneously monitor the time and probability of secondary gas explosions at key locations in the underground through multiple regional monitoring nodes 1, and transmit the determination results at corresponding locations in real time To the control computer 3, the judgment result can be viewed in real time through the display 4, and the judgment result can be saved in real time through the memory 5.

In this embodiment, the communication modules 1-7 in multiple regional monitoring nodes 1 communicate with the control computer 3 in a wired or wireless manner, and can upload the time and probability results of secondary gas explosions at multiple key locations underground to the The computer 3 and the memory 5 save the judgment results in real time to provide theoretical reference and guidance for command and decision-making of thermal power disaster rescue.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any way. All simple modifications, changes and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still belong to the technical aspects of the present invention. within the scope of protection of the scheme.

Claims (5)

1. The method for judging the secondary gas explosion in the mine thermodynamic disaster rescue process is characterized in that the method comprises the following steps: Step 1. Determine the location of the secondary gas explosion: install regional monitoring nodes (1) at multiple key locations in the mine to collect the temperature parameters of the corresponding areas and transmit the temperature parameters of the area to the control panel installed in the monitoring room in real time. The computer (3) sets the temperature parameter threshold through the keyboard input module (2), adopts the control computer (3) to calibrate the described key position reaching the temperature parameter threshold, and predicts the position where the secondary gas explosion takes place; the key position includes The air inlet tunnel of the working face, the return air tunnel of the working face, the middle part of the working face, the return air corner of the working face, the main air inlet belt roadway, the area affected by the high temperature smoke flow after the previous mine thermodynamic disaster and the area near the live electrical appliances and the abnormal gas surge The affected area; The regional monitoring node (1) includes a regional controller (1-6) and a clock circuit (1-5) and a communication module (1-7) connected with the regional controller (1-6), and the regional controller ( The input terminal of 1-6) is connected with a temperature sensor (1-1), a wind speed sensor (1-2), a gas sensor (1-8), a gas monitor ( 1-3) and an oxygen monitor (1-4) for collecting oxygen concentration and oxygen flow in the monitored area; Step 2. Estimate the time of the secondary gas explosion in the monitored area, the process is as follows: Step 201, obtain the environmental parameters of the monitored area: monitor the ventilation status of the monitored area through the wind speed sensor (1-2), monitor the monitored area through the gas monitor (1-3) and the oxygen monitor (1-4) respectively gas content and oxygen content; Step 202, judging whether the monitored area is an area where high-concentration gas explosions occur: set the monitoring parameter change time threshold through the area controller (1-6), and record according to the environmental parameters obtained in step 201 and the clock circuit (1-5) The change time of the environmental parameters in the post-disaster monitoring area is used to determine whether the monitored area is a high-concentration gas explosion area. When the limit time is less than the monitoring parameter change time threshold, it means that the monitored area is an area where a high-concentration gas explosion occurs, and step 203 is performed; otherwise, step 204 is performed; Step 203, estimate the time when the high-concentration gas explosion occurs, the process is as follows: Step 2031, according to the formula By solving the differential equation, the time t ₁ and the time t ₂ for the change of the oxygen concentration and the change of the methane concentration in the high-concentration gas explosion area can be obtained, where, V is the volume of the high-concentration gas explosion area, q ₁ is the flow rate of the mixed gas flowing into the high-concentration gas explosion area, q ₂ is the flow rate of the mixed gas flowing out of the high-concentration gas explosion area, and c ₁ is the oxygen flow into the high-concentration gas explosion area c ₂ is the concentration of methane flowing into the high-concentration gas explosion area, c ₀₁ is the initial value of oxygen concentration when the initial condition t ₁ =0, is the target value of the oxygen concentration to be achieved, c ₀₂ is the initial value of the methane concentration when the initial condition t ₂ =0, is the target value to be achieved by the methane concentration; Step 2032, according to the formula Calculate the time T ₁ for the oxygen concentration to become 12% in the post-disaster high-concentration gas explosion area, the time T 21 for the gas concentration to reach the lower explosion limit of 5%, and the time T ₂₂ for the gas concentration to reach the upper explosion limit of ₁₆ %; Step 2033, estimate the time when the high-concentration gas explosion occurs: when the time T ₁ >T ₂₂ elapsed when the oxygen concentration becomes 12% in step 2032, the high-concentration gas explosion does not occur; when the oxygen concentration becomes 12% in step 2032 When the elapsed time T ₂₁ ≤ T ₁ ≤ T ₂₂ , the high-concentration gas explosion occurs at a time t that satisfies: T ₁ + t ₃ ≤ t ≤ T ₂₂ + t ₃ , where t ₃ is the gas that reaches the gas explosion limit Time to the fire source; when the time T ₁ <T ₂₁ for the oxygen concentration to become 12% in step 2032, the time t for the explosion of high-concentration gas satisfies: T ₂₁ +t ₃ ≤t≤T ₂₂ +t ₃ ; Step 204, estimate the time when the low-concentration gas explosion occurs, the process is as follows: Step 2041, according to the formula By solving the differential equation, the time t' ₁ and the time t' ₂ for the change of the oxygen concentration and the change of the methane concentration in the low-concentration gas explosion area can be obtained, where, V' is the volume of the low-concentration gas explosion area, q' ₁ is the flow rate of the mixed gas flowing into the low-concentration gas explosion area, q' ₂ is the flow rate of the mixed gas flowing out of the low-concentration gas explosion area, c' ₁ is the flow rate of the low-concentration gas explosion area The concentration of oxygen in the explosion area, c' ₂ is the concentration of methane flowing into the low-concentration gas explosion area, c' ₀₁ is the initial value of oxygen concentration when the initial condition t' ₁ =0, c' ₀₂ is the initial condition t' ₂ = 0, the initial value of methane concentration; Step 2042, according to the formula Calculate the time T' ₁ for the oxygen concentration in the low-concentration gas explosion area to become 12% after the disaster, the time T' ₂₁ for the gas concentration to reach 5% of the lower explosion limit, and the time T' ₂₂ for the gas concentration to reach 16% of the upper limit of the explosion ; Step 2043. Estimate the occurrence time of the low-concentration gas explosion: when the time T' ₁ >T' ₂₂ for the oxygen concentration to become 12% in step 2042, the time t' for the low-concentration gas explosion satisfies: T' ₂₁ + t' ₃ ≤ t' ≤ T' ₂₂ + t'₃; when the time T' ₂₁ ≤ T' ₁ ≤ T' ₂₂ elapsed when the oxygen concentration becomes 12% in step 2042, the time t when the low-concentration gas explosion occurs 'Satisfy: T' ₂₁ +t' ₃ ≤ t' ≤ T' ₁ + t'₃; when the time T' ₁ <T' ₂₁ elapsed when the oxygen concentration becomes 12% in step 2042, the low-concentration gas explosion will not Occurrence, wherein, t' ₃ is the time when the gas reaching the limit of gas explosion encounters the fire source; Step 3. Estimate the probability of secondary gas explosion in the monitored area: According to the gas explosion accident tree analysis method, the probability of gas explosion P=P ₁ ×P ₂ ×P ₃ , where P ₁ is the gas concentration in the monitored area after the disaster The probability of reaching the gas explosion limit and P ₁ satisfies according to the Kovad explosion triangle: P ₁ =P _1i , i=1~4 and P ₁₁ =1>P ₁₃ >P ₁₂ >P ₁₄ =0, P ₁₁ is the gas concentration Probability of the gas explosion limit when the gas concentration is between 5% and 16% and the oxygen concentration is greater than 12%, P ₁₂ is the probability of the gas explosion limit when the gas concentration is between 5% and 16% and the oxygen concentration is less than 12%, P ₁₃ is the probability of the gas explosion limit when the gas concentration is greater than 16% and the oxygen concentration is less than 12%, and P ₁₄ is the probability of the gas explosion limit when the gas concentration is less than 5%. Both the probability P ₁₂ and the probability P ₁₃ are estimated by the expert scoring method Probability value, P ₂ is the probability that there is a fire source that can cause a gas explosion in the monitored area after the disaster, and P ₃ is the probability that the gas that reaches the gas explosion limit in the monitored area after the disaster meets the fire source; Step 4. Display and real-time storage of secondary gas explosion determination results: Simultaneously monitor the time and probability of secondary gas explosions at the key positions in the underground through multiple regional monitoring nodes (1), and store the determination results at the corresponding positions Real-time transmission to the control computer (3), the judgment result can be viewed in real time through the display (4), and the judgment result is saved in real time through the memory (5). 2. The method for judging secondary gas explosions in the mine thermodynamic disaster rescue process according to claim 1, characterized in that: the key positions in step 1 and step 4 include the air inlet tunnel of the working face and the return air tunnel of the working face , the middle of the working face, the return air corner of the working face, the main air inlet belt roadway, the area affected by high-temperature smoke flow after the previous mine thermodynamic disaster, and the area near live electrical appliances and affected by abnormal gas gushing. 3. According to the method for judging the secondary gas explosion in the mine thermodynamic disaster rescue process according to claim 1, it is characterized in that: in step 3, the probability Among them, N is the number of experts, p _12j is the probability of the gas explosion limit given by the jth expert when the gas concentration is between 5% and 16% and the oxygen concentration is less than 12%, δ _j is the weight corresponding to p _12j and p _13j is the probability of the gas explosion limit given by the jth expert when the gas concentration is greater than 16% and the oxygen concentration is less than 12%, δ _j ' is the weight corresponding to p _13j and 4. According to the method for judging the secondary gas explosion in the mine thermodynamic disaster rescue process according to claim 1, it is characterized in that: in step 3, the probability Among them, the probability P ₂₁ is the probability that the fire source in the monitored area after the disaster is a persistent fire source and P ₂₁ =1, and the probability P ₂₂ is the probability that the fire source in the monitored area after the disaster is a transient fire source and 0≤P ₂₂ ≤1. 5. The method for judging secondary gas explosions in mine thermodynamic disaster rescue process according to claim 1, characterized in that in step 3, the probability P ₃ =1.