Real-time monitoring and spontaneous combustion simulation combined coal-fired reactor spontaneous combustion early warning system and method

Abstract

The invention provides a real-time monitoring and spontaneous combustion simulation combined coal-fired pile spontaneous combustion early warning system and method, and belongs to the technical field of fire coal storage. The method comprises the following steps: acquiring real-time temperature monitoring data, real-time gas monitoring data and real-time volatile gas concentration monitoring data after the completion of self-stacking of a to-be-fired coal pile, respectively drawing a temperature-time curve, a humidity-time curve and a volatile gas concentration-time curve, and carrying out real-time monitoring; randomly sampling from a coal-fired pile to form a simulation model, then heating the simulation model, supplementing water and volatile gas, simulating the change process of the coal-fired pile, and observing whether the simulation model is on fire and spontaneously combusted; and coal-fired pile spontaneous combustion early warning. The system comprises a first temperature sensor, a second humidity sensor, a first gas concentration sensor, a simulation cavity, an electric heating element, a water supplementing pipe, a gas supplementing pipe and a central processing unit. According to the invention, beforehand early warning can be realized, a large amount of data operation is not involved, and the construction cost is relatively low.

Description

Technical Field

[0001] The present invention relates to the technical field of coal storage, and particularly to a spontaneous combustion early warning system and method for coal piles combining real-time monitoring and spontaneous combustion simulation. Background Art

[0002] The spontaneous combustion of coal piles is a complex combustion system driven by both internal and external factors and affected by various factors such as oxidation, temperature, depth, thermal conductivity, grain size, coalification degree, volatile components, and structure. Therefore, the coal piles stored in the coal yard need to be regularly inspected by workers. Once internal spontaneous combustion occurs, it is not only likely to cause fire accidents but also result in waste of resources.

[0003] Chinese Invention Patent (Title: "Method for Monitoring Spontaneous Combustion of Coal Piles and Prevention and Control System", Publication No.: CN111311870B, Authorization Publication Date: 20210622) discloses a method for monitoring spontaneous combustion of coal piles and a prevention and control system. The system includes an air extraction and temperature measurement combined device composed of a gas extraction bundle tube and an armored temperature measurement optical fiber for extracting index gases inside the coal pile and collecting the temperature of the surrounding coal body; a smoke detection and inspection device for detecting the smoke concentration on the surface of the coal pile and sending signals; a radon measurement device for collecting radon in the coal pile and sending signals; an infrared detection device for collecting infrared images of the coal pile and on-site detection videos; a signal receiving device for receiving signals collected by the smoke detection and inspection device, the infrared detection device, and the radon measurement device; a data processing device connected to the signal receiving and air extraction and temperature measurement combined device to comprehensively judge the smoldering situation inside the coal pile; and a spontaneous combustion prevention and control fire extinguishing system that executes different fire extinguishing control measures according to the combustion situation inside the coal pile. However, this method for monitoring spontaneous combustion of coal piles and prevention and control system is still post-event monitoring, that is, monitoring after spontaneous combustion has occurred in the coal pile.

[0004] Chinese Invention Patent Application (Title: "Spontaneous Combustion Risk Early Warning System for Coal Piles", Publication No.: CN119206986A, Publication Date: 20241227) discloses a spontaneous combustion risk early warning system for coal piles, including data collection, big data model, and intelligent early warning functions. The system consists of an environmental data collection system, a coal pile surface temperature data collection system, a coal pile bottom temperature collection system, a coal temperature big data system, and a coal pile spontaneous combustion early warning management system. According to the coal heating principle and self-oxidation characteristics, using big data technology to calculate the big data of the coal pile and evaluate the possible fire risks of the coal pile. When the risk exceeds the preset risk index, the system issues an alarm to the management personnel to assist the coal yard management personnel in making decisions and reducing the potential loss risk. This spontaneous combustion risk early warning system for coal piles uses big data technology models, etc. for simulation, which requires relatively high computing power and relatively large investment. Summary of the Invention

[0005] The present invention aims to provide a spontaneous combustion early warning system and method for coal piles that combines real-time monitoring and spontaneous combustion simulation, which can simulate and pre-enact the spontaneous combustion process in advance to achieve early warning and can interfere with the coal piles in advance; at the same time, using a physical simulation model does not involve a large amount of data operation, and the system construction cost is relatively low; furthermore, the combination of real-time monitoring and spontaneous combustion simulation can make up for the deficiencies of a single monitoring method with poor effects.

[0006] The technical solution adopted by the present invention is as follows: A spontaneous combustion early warning method for coal piles that combines real-time monitoring and spontaneous combustion simulation, comprising the following steps: Step S1, obtain the real-time temperature monitoring data, real-time gas monitoring data, and real-time volatile gas concentration monitoring data of the coal pile to be monitored after stacking is completed, respectively draw a temperature-time curve, a humidity-time curve, and a volatile gas concentration-time curve, and conduct real-time monitoring; Step S2, randomly sample from the coal pile to form a simulation model, and the simulation model is formed by scaling the coal pile in equal proportion; based on the temperature change rate, humidity change rate, and volatile gas concentration change rate calculated from the temperature-time curve, the humidity-time curve, and the volatile gas concentration-time curve, heat the simulation model, and supplement moisture and volatile gas to simulate the change process of coal stacking, and observe whether the simulation model catches fire and undergoes spontaneous combustion; Step S3, based on the real-time monitoring results in Step S1 and the simulation results in Step S2, conduct early warning of spontaneous combustion of the coal pile.

[0007] Further, the specific process in Step S1 includes the following: Step S11, divide a plurality of monitoring surfaces from the bottom surface of the coal pile according to the height of the coal pile, and set a plurality of monitoring points on each monitoring surface; a first temperature sensor is provided at each monitoring point; at least one monitoring point on each monitoring surface is also provided with a first humidity sensor and a first gas concentration sensor; Step S12, based on the real-time temperature monitoring data obtained by each first temperature sensor, respectively draw the corresponding temperature-time curve for real-time monitoring; Step S13, based on the average value of the real-time humidity monitoring data obtained by all the first humidity sensors, draw the corresponding humidity-time curve for real-time monitoring; Step S14, based on the average value of the real-time volatile gas concentration monitoring data obtained by all the first gas concentration sensors, draw the corresponding volatile gas concentration-time curve for real-time monitoring.

[0008] Further, in step S12, if the real-time temperature monitoring data corresponding to a certain moment exceeds the temperature monitoring threshold, a risk warning is issued; or, if it is predicted based on the temperature-time curve that the real-time temperature monitoring data corresponding to a certain future moment will exceed the temperature monitoring threshold, a risk warning is issued before the predicted future moment. In step S13, if the real-time humidity monitoring data corresponding to a certain moment exceeds the humidity monitoring threshold, a risk warning is issued; or, if it is predicted based on the humidity-time curve that the real-time humidity monitoring data corresponding to a certain future moment will exceed the humidity monitoring threshold, a risk warning is issued before the predicted future moment. In step S14, if the real-time volatile gas concentration monitoring data corresponding to a certain moment exceeds the gas concentration monitoring threshold, a risk warning is issued; or, if it is predicted based on the volatile gas concentration-time curve that the real-time volatile gas concentration monitoring data corresponding to a certain future moment will exceed the gas concentration monitoring threshold, a risk warning is issued before the predicted future moment.

[0009] Further, the specific process of step S2 includes: Step S21: Construct a hollow simulation stacking skeleton by scaling the outer contour information of the coal pile proportionally, and set a non-woven fabric layer on the simulation stacking skeleton to form a simulation cavity; a relatively large bottom opening is reserved on the simulation cavity. Step S22: Randomly collect a coal sample from the coal pile, with the stacking volume of the coal sample being greater than or equal to the volume of the simulation cavity, and manually turn and stir it. Step S23: Flip the simulation cavity so that its open end faces upward, and then load the mixed coal sample into the simulation model cavity; meanwhile, during the loading process, several electric heating elements are arranged on the divided loading surface, and a second temperature sensor is also provided near each electric heating element; the position of the loading surface corresponds to the position of the monitoring surface in the coal pile, and the position of the electric heating element is arranged with reference to the position of the first temperature sensor; a second humidity sensor and a second gas concentration sensor are also arranged in the simulation model cavity; finally, flip the simulation cavity to form the simulation model. Step S24: Obtain the initial temperature, initial humidity, and initial volatile gas concentration of the simulation model by the second temperature sensor, the second humidity sensor, and the second gas concentration sensor respectively; based on the temperature change rate, humidity change rate, and volatile gas concentration change rate calculated from the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, heat the simulation model, and supplement moisture and volatile gas to simulate the change process of coal stacking, and observe whether the simulation model catches fire and self-ignites.

[0010] Furthermore, the step S24 specifically includes the following process: Step S241, the second temperature sensor, the second humidity sensor and the second gas concentration sensor respectively obtain the initial temperature data, the initial humidity data and the initial volatile gas concentration data of the simulation model, and respectively calculate the average values ​​of all the corresponding initial temperature data, the initial humidity data and the initial volatile gas concentration data. If the average values ​​of the initial temperature data, the average values ​​of the initial humidity data and the initial volatile gas concentration data are all less than or equal to the real-time temperature monitoring data, the real-time humidity monitoring data and the real-time volatile gas concentration monitoring data corresponding to the completion of the initial stacking of the coal pile, then the next step is executed; Step S242, adding water into the simulation model according to the volatile gas concentration - the humidity change rate calculated according to the humidity-time curve, until the humidity monitoring data of the second humidity sensor is equal to the average value of the real-time humidity monitoring data of all the first humidity sensors; Step S243, replenishing volatile gas into the simulation model according to the volatile gas concentration change rate calculated from the volatile gas concentration-time curve, until the volatile gas concentration data of the second gas concentration sensor is equal to the average value of the real-time volatile gas concentration monitoring data of all the first gas concentration sensors; Step S244, divide the adjacent first temperature sensors on the same monitoring surface into a group and correspond them to one of the electric heating elements on the corresponding loading surface; draw the temperature-time curve based on the average value of the real-time temperature monitoring data obtained by all the first temperature sensors in the same group to calculate the temperature change rate, and heat the simulation model with the temperature change rate by the corresponding electric heating element, and the single heating time is set according to the simulation requirements, or the simulation model is heated by the electric heating element to the average value of the temperature monitoring data of the corresponding second temperature sensor and the real-time temperature monitoring data of the first temperature sensor in the corresponding group; observe whether the simulation model catches fire or spontaneous combustion.

[0011] Furthermore, in step S244, spontaneous combustion monitoring is performed using one or more of an infrared thermal imager, an open flame detector, a smoke sensor and a carbon dioxide monitor.

[0012] Furthermore, the step S3 specifically includes the following process: Step S31, if the real-time monitoring result is normal, and the coal pile in the simulation result spontaneously combusts, a low-frequency spontaneous combustion warning prompt is issued; Step S32, if the result of real-time monitoring shows a risk while the simulated coal pile has not caught fire, then issue a spontaneous combustion attention prompt. Step S33, if the result of real-time monitoring shows a risk and at the same time the simulated coal pile has caught fire, then issue a high-frequency spontaneous combustion early warning prompt.

[0013] Based on the same inventive concept, the present invention also provides a spontaneous combustion early warning system for a coal pile combining real-time monitoring and spontaneous combustion simulation to implement the foregoing method for early warning of spontaneous combustion of a coal pile combining real-time monitoring and spontaneous combustion simulation, including: A first temperature sensor, which is arranged inside the coal pile and is used to obtain real-time temperature monitoring data of the coal pile to be monitored since the stacking is completed. A second humidity sensor, which is arranged inside the coal pile and is used to obtain real-time humidity monitoring data of the coal pile to be monitored since the stacking is completed. A first gas concentration sensor, which is arranged inside the coal pile and is used to obtain real-time gas concentration monitoring data of the coal pile to be monitored since the stacking is completed. A simulation cavity, which is scaled proportionally according to the outer contour information of the coal pile, and forms a simulation model after filling with coal samples collected from the coal pile. An electric heating element, which is arranged inside the simulation model. A water supply pipe, the output end of which is inserted into the simulation model. A gas supply pipe, the output end of which is inserted into the simulation model. A central processing unit, which is used to draw temperature-time curves, humidity-time curves and volatile gas concentration-time curves and conduct real-time monitoring, and based on the temperature change rate, humidity change rate and volatile gas concentration change rate calculated from the temperature-time curve, the humidity-time curve and the volatile gas concentration-time curve, respectively control the heating of the simulation model by the electric heating element, the supplement of moisture by the water supply pipe and the supplement of volatile gas by the gas supply pipe.

[0014] Furthermore, it further includes: A second temperature sensor, which is arranged near the electric heating element inside the simulation model, and the two are in one-to-one correspondence, and is used to obtain the initial temperature data of the simulation model and subsequent temperature data. A second humidity sensor, which is arranged inside the simulation model and is used to obtain the initial humidity data of the simulation model and subsequent humidity data. A second gas concentration sensor, which is disposed within the simulation model and is used to obtain the initial gas concentration data of the simulation model and subsequent gas concentration data.

[0015] Furthermore, it further includes: A spontaneous combustion monitoring device, which adopts one or more of an infrared thermal imager, an open fire monitor, a smoke sensor, and a carbon dioxide monitor.

[0016] The beneficial effects of the present invention are: The present invention provides a coal pile spontaneous combustion early warning system and method combining real-time monitoring and spontaneous combustion simulation. On the one hand, it continuously monitors the real-time temperature, real-time humidity, and real-time gas concentration of the coal pile. On the other hand, by constructing a simulation model that is scaled proportionally to the coal pile, and then based on the temperature change rate, humidity change rate, and volatile gas concentration change rate calculated from the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, heating the simulation model, supplementing moisture and volatile gases, simulating the change process of coal pile placement, observing whether spontaneous combustion occurs in the simulation model, and finally giving a spontaneous combustion early warning based on the results of real-time monitoring and simulation. The present invention can simulate and pre-enact the spontaneous combustion process in advance, achieve early warning, and can interfere with the coal pile in advance; at the same time, using a physical simulation model does not involve a large amount of data operation, and the system construction cost is relatively low; furthermore, the combination of real-time monitoring and spontaneous combustion simulation can make up for the defect of poor effect of a single monitoring method. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic flowchart of the coal pile spontaneous combustion early warning method combining real-time monitoring and spontaneous combustion simulation in Embodiment 1.

[0019] Figure 2 It is a schematic diagram of a conical coal pile in Embodiment 1.

[0020] Figure 3 It is a schematic diagram of the temperature-time curve in Embodiment 1.

[0021] Figure 4 It is a schematic diagram of the humidity-time curve in Embodiment 1.

[0022] Figure 5Schematic diagram of the volatile gas concentration-time curve in Example 1. Detailed implementation mode

[0023] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0024] The following disclosure provides many different implementation modes or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention.

[0025] The embodiments of the invention will be described in detail below with reference to the drawings.

[0026] Example 1

[0027] Figure 1 Schematic diagram of the process of the spontaneous combustion warning method for coal piles combining real-time monitoring and spontaneous combustion simulation in Example 1. As Figure 1 shown, the spontaneous combustion warning method for coal piles combining real-time monitoring and spontaneous combustion simulation includes the following steps: Step S1, obtain the real-time temperature monitoring data, real-time gas monitoring data, and real-time volatile gas concentration monitoring data of the coal pile to be monitored after the stacking is completed, respectively plot the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, and conduct real-time monitoring; Step S2, randomly sample from the coal pile to form, and the simulation model is formed by scaling the coal pile in equal proportion; based on the temperature change rate, humidity change rate, and volatile gas concentration change rate calculated from the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, heat the simulation model, and supplement moisture and volatile gas to simulate the change process of coal pile placement, and observe whether the simulation model catches fire and undergoes spontaneous combustion; Step S3, conduct a spontaneous combustion warning for the coal pile based on the real-time monitoring results in Step S1 and the simulation results in Step S2.

[0028] In this embodiment, through the above steps, on the one hand, the real-time temperature, real-time humidity and real-time gas concentration of the coal pile are continuously monitored in real time, and on the other hand, a simulation model that is proportional to the coal pile is constructed, and then based on the temperature change rate (the slope of the temperature-time curve), humidity change rate (the slope of the humidity-time curve) and volatile gas concentration change rate (the slope of the volatile gas concentration-time curve) calculated from the temperature-time curve, the humidity-time curve and the volatile gas concentration-time curve, the simulation model is heated, and water and volatile gases (such as methane and carbon monoxide) are added to simulate the change process of coal stacking, observe whether the simulation model catches fire and self-ignites, and finally, a spontaneous combustion warning is given based on the results of real-time monitoring and simulation. In this embodiment, the process of coal pile ignition and self-ignition can be simulated and pre-rehearsed to achieve advance warning, and the coal pile can be interfered with in advance; at the same time, the use of a physical simulation model does not involve a large amount of data calculation, and the construction cost is relatively low; furthermore, the combination of real-time monitoring and spontaneous combustion simulation can make up for the defect of poor effect of a single monitoring method.

[0029] Furthermore, the step S1 specifically includes the following process: Step S11, dividing a plurality of monitoring surfaces from the bottom surface of the coal pile according to the height of the coal pile, and setting a plurality of monitoring points on each of the monitoring surfaces; a first temperature sensor is set at each of the monitoring points; at least one of the monitoring points on each of the monitoring surfaces is also set with a first humidity sensor and a first gas concentration sensor; Step S12, based on the real-time temperature monitoring data acquired by each of the first temperature sensors, respectively draw the corresponding temperature-time curves to perform real-time monitoring; Step S13, based on the average value of the real-time humidity monitoring data acquired by all the first humidity sensors, draw the corresponding humidity-time curve to perform real-time monitoring; Step S14: based on the average value of the real-time volatile gas concentration monitoring data acquired by all the first gas concentration sensors, draw the corresponding volatile gas concentration-time curve to perform real-time monitoring.

[0030] After the coal pile is finally stacked, it is mostly in the shape of a truncated cone or a cone, such as Figure 2The conical coal pile shown has a bottom diameter of approximately 10 m and a height of approximately 5 m. Starting from the bottom of the coal pile, a monitoring surface is set every 0.5 m in the height direction, numbered from 1 to 5# monitoring surfaces. A total of 10 monitoring points are set at the center point A on the 1# monitoring surface and in the circumferential direction of a circle with a diameter of 5 m centered at point A, numbered from 1 to 10# monitoring points; the 2 - 10# monitoring points are evenly distributed in the circumferential direction; each of the 1 - 10# monitoring points is provided with a first temperature sensor, numbered from 1 to 10# first temperature sensors; at the same time, a first humidity sensor and a first gas concentration sensor are set at the center point A, numbered 1# first humidity sensor and 1# first gas concentration sensor. And so on, there are 11 - 19# monitoring points on the 2# monitoring surface, and 11 - 19# first temperature sensors, 2# first humidity sensor and 2# first gas concentration sensor are set; there are 20 - 27# monitoring points on the 3# monitoring surface, and 20 - 27# first temperature sensors, 3# first humidity sensor and 4# first gas concentration sensor are set; there are 28 - 34# monitoring points on the 4# monitoring surface, and 28 - 34# first temperature sensors, 4# first humidity sensor and 4# first gas concentration sensor are set; there are 35 - 40# monitoring points on the 5# monitoring surface, and 35 - 40# first temperature sensors, 5# first humidity sensor and 5# first gas concentration sensor are set. The first temperature sensors are used to detect the temperature change data inside the coal pile; the first humidity sensors are used to detect the humidity change data inside the coal pile; the first gas concentration sensors include methane sensors and carbon monoxide sensors, and are used to detect the concentration change data of volatile gases inside the coal pile; the 1 - 40# first temperature sensors, 1 - 5# first humidity sensors and 1 - 5# first gas concentration sensors all obtain monitoring data every 1 h.

[0031] For the real - time temperature monitoring data respectively obtained by the 1 - 40# first temperature sensors, a temperature - time curve as shown in Figure 3 can be plotted; for the average value of the real - time humidity monitoring data obtained by the 1 - 5# first humidity sensors, a humidity - time curve as shown in Figure 4 can be plotted; for the average value of the real - time volatile gas concentration monitoring data obtained by the 1 - 5# first gas concentration sensors, a volatile gas concentration - time curve as shown in Figure 5 can be plotted.

[0032] Generally speaking, the influencing factors of coal pile spontaneous combustion are relatively complex. Among them, the relatively large self - influencing factors of the coal pile are temperature, humidity and volatile gas concentration. In this embodiment, through the real - time monitoring of temperature, humidity and volatile gas concentration, it provides one - aspect supporting data for the early warning of coal pile spontaneous combustion.

[0033] In the step S12, if the real-time temperature monitoring data corresponding to a certain moment exceeds the temperature monitoring threshold, a risk prompt is issued; or, if it is inferred from the temperature-time curve that the real-time temperature monitoring data corresponding to a certain future moment will exceed the temperature monitoring threshold, a risk prompt is issued before the inferred future moment; In the step S13, if the real-time humidity monitoring data corresponding to a certain moment exceeds the humidity monitoring threshold, a risk prompt is issued; or, if it is inferred from the humidity-time curve that the real-time humidity monitoring data corresponding to a certain future moment will exceed the humidity monitoring threshold, a risk prompt is issued before the inferred future moment; In the step S14, if the real-time volatile gas concentration monitoring data corresponding to a certain moment exceeds the gas concentration monitoring threshold, a risk prompt is issued; or, if it is inferred from the volatile gas concentration-time curve that the real-time volatile gas concentration monitoring data corresponding to a certain future moment will exceed the gas concentration monitoring threshold, a risk prompt is issued before the inferred future moment.

[0034] In this embodiment, not only is it concerned with whether the real-time temperature monitoring data exceeds the temperature monitoring threshold, whether the real-time humidity monitoring data exceeds the humidity monitoring threshold, and whether the real-time volatile gas concentration monitoring data exceeds the gas concentration monitoring threshold, but also fitting inferences can be made based on the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, greatly improving the reliability of the real-time monitoring results.

[0035] Further, the specific process of the step S2 includes: Step S21, constructing a hollow simulation stacking skeleton by scaling the outer contour information (such as the bottom size, height, etc.) of the coal pile in proportion, and setting a non-woven fabric layer on the simulation stacking skeleton to form a simulation cavity; a relatively large bottom opening is reserved on the simulation cavity; Step S22, randomly collecting coal samples from the coal pile, the stacking volume of the coal samples being greater than or equal to the volume of the simulation cavity, and manually turning and stirring; Step S23, turning the simulation cavity so that its open end faces upward, and then loading the mixed coal samples into the simulation model cavity; meanwhile, during the loading process, a number of electric heating elements are arranged on the divided loading surface, and a second temperature sensor is also provided near each electric heating element; the position of the loading surface corresponds to the position of the monitoring surface in the coal pile, and the position of the electric heating element is arranged with reference to the position of the first temperature sensor; a second humidity sensor and a second gas concentration sensor are also arranged in the simulation model cavity; finally, turn the simulation cavity to form the simulation model; Step S24: Obtain the initial temperature, initial humidity, and initial concentration of volatile gases of the simulation model by the second temperature sensor, the second humidity sensor, and the second gas concentration sensor respectively; heat the simulation model, supplement moisture and volatile gases based on the temperature change rate, humidity change rate, and volatile gas concentration change rate calculated from the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, simulate the change process of coal stacking, and observe whether spontaneous ignition occurs in the simulation model.

[0036] In previous studies, the applicant also tried many times to directly use coal samples randomly collected from the coal pile for subsequent simulation. However, the simulation effect was not good, and the results of spontaneous combustion early warning were not ideal. The applicant analyzed that the reason was that the amount of coal samples was relatively small, and the stacking volume was also small, so heat, moisture, and volatile gases were easily lost quickly, and thus the internal changes of the coal pile after stacking could not be accurately simulated. After a large number of attempts, the applicant first used round steel bars with a diameter of 6.5 mm to build and weld each other to form a stacking skeleton of the simulation model. The outer contour of the stacking skeleton of the simulation model was scaled proportionally according to the outer contour information of the actual coal pile; then, a non-woven fabric layer was laid on the inner side of the stacking skeleton of the simulation model, leaving a large-diameter bottom opening, forming a conical simulation model cavity. For example, according to Figure 2 the conical coal pile shown in the figure with a bottom diameter of about 10 m and a height of about 5 m was scaled proportionally to form a conical stacking skeleton of the simulation model with a bottom diameter of about 1 m and a height of about 0.5 m. The total thickness of the non-woven fabric layer was 1.5 mm. The simulation model cavity was filled with coal samples, and electric heating elements, a second temperature sensor, a second humidity sensor, and a second gas concentration sensor were set as required. For example, the bottom surface of the simulation model corresponding to the 1# monitoring surface in the aforementioned conical coal pile with a bottom diameter of about 10 m and a height of about 5 m; the 1~10# first temperature sensors were divided into four groups, the 1# first temperature sensor, the 2~4# first temperature sensors, the 5~7# first temperature sensors, and the 8~10# first temperature sensors, corresponding to the 1~4# electric heating elements respectively; the 1# electric heating element was located at the center of the corresponding filling surface, and the 2~4# electric heating elements were evenly arranged in a circular manner, that is, referring to the arrangement method of the first temperature sensors; the 1~4# second temperature sensors were respectively arranged near the corresponding 1~4# electric heating elements; the second humidity sensor and the second gas concentration sensors (methane sensor and carbon monoxide sensor) were respectively arranged near the middle of the height direction in the simulation model, and the distance between the two was 5 cm; and so on, the corresponding electric heating elements and second temperature sensors were set on the remaining four filling surfaces.

[0037] In this embodiment, a simulation model stacking skeleton is first formed, then a non-woven fabric layer is set in the cavity of the simulation model, and finally a coal sample is filled to finally form a simulation model. On the one hand, the simulation model can more accurately simulate the outer contour of the coal pile and the laying of corresponding electric heating elements, second temperature sensors, etc.; on the other hand, the non-woven fabric layer can block the loss of heat, moisture and volatile gases in the coal sample and better simulate the internal changes of the coal pile after stacking is completed.

[0038] The specific process in step S24 includes the following: Step S241: The second temperature sensor, the second humidity sensor and the second gas concentration sensor respectively obtain the initial temperature data, the initial humidity data and the initial volatile gas concentration data of the simulation model, and calculate the average values of all the corresponding initial temperature data, initial humidity data and initial volatile gas concentration data respectively. If the average value of the initial temperature data, the average value of the initial humidity data and the average value of the initial volatile gas concentration data are all less than or equal to the corresponding real-time temperature monitoring data, real-time humidity monitoring data and real-time volatile gas concentration monitoring data when the coal pile is initially stacked, then proceed to the next step; if the average value of the initial temperature data, the average value of the initial humidity data or the average value of the initial volatile gas concentration data is greater than the corresponding real-time temperature monitoring data, real-time humidity monitoring data or real-time volatile gas concentration monitoring data when the coal pile is initially stacked, then place the simulation model in a cool and ventilated place until the average value of the initial temperature data, the average value of the initial humidity data and the average value of the initial volatile gas concentration data are all less than or equal to the corresponding real-time temperature monitoring data, real-time humidity monitoring data and real-time volatile gas concentration monitoring data when the coal pile is initially stacked; Step S242: Supplement water into the simulation model according to the humidity change rate calculated from the humidity-time curve of the volatile gas concentration until the humidity monitoring data of the second humidity sensor is equivalent to the average value of the real-time humidity monitoring data of all the first humidity sensors (the two values are close or the absolute value of the difference between the two is less than or equal to 0.1); Step S243: Supplement volatile gas into the simulation model according to the volatile gas concentration change rate calculated from the volatile gas concentration-time curve until the volatile gas concentration data of the second gas concentration sensor is equivalent to the average value of the real-time volatile gas concentration monitoring data of all the first gas concentration sensors (the two values are close or the absolute value of the difference between the two is less than or equal to 0.1); Step S244, divide the adjacent first temperature sensors on the same monitoring surface into a group and correspond to one of the electric heating elements on the corresponding loading surface; draw the temperature-time curve based on the average value of the real-time temperature monitoring data obtained by all the first temperature sensors in the same group to calculate the temperature change rate, and heat the simulation model with the corresponding electric heating element at the temperature change rate, and the single heating time is set according to the simulation requirements (for example, the single heating time is 20 minutes), or the electric heating element heats the simulation model until the temperature monitoring data of the corresponding second temperature sensor is equivalent to the average value of the real-time temperature monitoring data of the first temperature sensor in the corresponding group (the two values ​​are close or the absolute value of the difference between the two is less than or equal to 0.1); observe whether the simulation model catches fire or self-ignites. In the step S244, one or more of an infrared thermal imager, an open fire detector, a smoke sensor and a carbon dioxide monitor are used for spontaneous combustion monitoring.

[0039] In this embodiment, the temperature, humidity and volatile gas concentration of the simulation model are first adjusted to be less than or equal to the real-time temperature monitoring data, real-time humidity monitoring data and real-time volatile gas concentration monitoring data corresponding to the initial stacking of the coal pile, and then the subsequent heating, water replenishment and gas replenishment operations are performed, which is conducive to making the simulation results closer to the actual state, without large deviations from the actual initial temperature, humidity and volatile gas concentration. At the same time, the heating process can control the duration of a single heating to simulate the change process of the coal pile under a continuous heating state under specific humidity and gas concentration, and can also be heated to be equivalent to the average value of the corresponding real-time temperature monitoring data to simulate the change process of the coal pile under an equivalent heating state, which is suitable for different monitoring needs.

[0040] Furthermore, the step S3 specifically includes the following process: Step S31: If the real-time monitoring result is normal, but the coal pile in the simulation result spontaneously combusts, a low-frequency spontaneous combustion warning prompt is issued, for example, a spontaneous combustion warning prompt is issued every 1 hour; Step S32: If the real-time monitoring result shows that there is a risk, and the coal pile in the simulation result does not spontaneously combust, a spontaneous combustion attention prompt is issued; Step S33: If the result of real-time monitoring indicates that there is a risk and the simulated result shows that the coal pile spontaneously combusts, a high-frequency spontaneous combustion warning prompt is issued, for example, a spontaneous combustion warning prompt is issued every 20 minutes.

[0041] In this embodiment, the two technical means of real-time monitoring and spontaneous combustion simulation are combined and associated with each other, which can make up for the defect of poor effect of a single monitoring means.

[0042] Example 2

[0043] In this embodiment, a spontaneous combustion early warning system for coal piles that combines real-time monitoring and spontaneous combustion simulation is provided to implement the method for early warning of spontaneous combustion of coal piles that combines real-time monitoring and spontaneous combustion simulation in the foregoing Embodiment 1. The system includes: a first temperature sensor, a second humidity sensor, a first gas concentration sensor, a simulation cavity, an electric heating element, a water supply pipe, a gas supply pipe, and a central processor. Among them, the first temperature sensor is arranged inside the coal pile and is used to obtain the real-time temperature monitoring data of the coal pile to be monitored after the stacking is completed; the second humidity sensor is arranged inside the coal pile and is used to obtain the real-time humidity monitoring data of the coal pile to be monitored after the stacking is completed; the first gas concentration sensor is arranged inside the coal pile and is used to obtain the real-time gas concentration monitoring data of the coal pile to be monitored after the stacking is completed; the simulation cavity is scaled proportionally according to the outer contour information of the coal pile, and forms a simulation model after being filled with coal samples collected from the coal pile; the electric heating element is arranged inside the simulation model and is used to heat the simulation model; the output end of the water supply pipe is inserted into the simulation model and is used to introduce liquid water or atomized water into the simulation model; the output end of the gas supply pipe is inserted into the simulation model and is used to introduce volatile gases (such as methane and carbon monoxide) into the simulation model; the central processor is used to draw temperature-time curves, humidity-time curves, and volatile gas concentration-time curves and perform real-time monitoring, and then, based on the temperature change rate (the slope of the temperature-time curve), humidity change rate (the slope of the humidity-time curve), and volatile gas concentration change rate (the slope of the volatile gas concentration-time curve) calculated from the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, respectively control the heating of the simulation model by the electric heating element, the supplement of moisture by the water supply pipe, and the introduction of volatile gases by the gas supply pipe.

[0044] The spontaneous combustion early warning system for coal piles that combines real-time monitoring and spontaneous combustion simulation in this embodiment can achieve early warning in advance, does not involve a large amount of data operations, and the system construction cost is relatively low.

[0045] Furthermore, it further includes: a second temperature sensor, which is arranged near the electric heating element inside the simulation model, and the two are in one-to-one correspondence, and is used to obtain the initial temperature data of the simulation model and subsequent temperature data; a second humidity sensor, which is arranged inside the simulation model and is used to obtain the initial humidity data of the simulation model and subsequent humidity data; a second gas concentration sensor, which is arranged inside the simulation model and is used to obtain the initial gas concentration data of the simulation model and subsequent gas concentration data.

[0046] Furthermore, it further includes: a spontaneous combustion monitoring device, and the spontaneous combustion monitoring device adopts one or more of an infrared thermal imager, an open fire monitor, a smoke sensor, and a carbon dioxide monitor.

Claims

1. A method for spontaneous combustion warning of coal piles combining real-time monitoring and spontaneous combustion simulation, characterized in that It includes the following steps: Step S1: Obtain the real-time temperature monitoring data, real-time gas monitoring data, and real-time volatile gas concentration monitoring data of the coal pile to be monitored since the stacking is completed, respectively plot the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, and conduct real-time monitoring; Step S2: Randomly sample from the coal pile to form a simulation model, which is formed by scaling the coal pile proportionally; Based on the temperature change rate, humidity change rate, and volatile gas concentration change rate calculated from the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, heat the simulation model, and supplement moisture and volatile gas to simulate the change process of coal stacking, and observe whether the simulation model catches fire and self-ignites; Step S3: Based on the real-time monitoring results in Step S1 and the simulation results in Step S2, conduct a self-ignition warning for the coal pile.

2. The self-ignition warning method for coal piles combining real-time monitoring and self-ignition simulation according to claim 1, characterized in that The specific process in Step S1 includes the following: Step S11: Divide multiple monitoring surfaces from the bottom surface of the coal pile according to the height of the coal pile, and set multiple monitoring points on each monitoring surface; A first temperature sensor is provided at each monitoring point; At least one monitoring point on each monitoring surface is also provided with a first humidity sensor and a first gas concentration sensor; Step S12: Based on the real-time temperature monitoring data obtained by each first temperature sensor, respectively plot the corresponding temperature-time curve and conduct real-time monitoring; Step S13: Based on the average value of the real-time humidity monitoring data obtained by all the first humidity sensors, plot the corresponding humidity-time curve and conduct real-time monitoring; Step S14: Based on the average value of the real-time volatile gas concentration monitoring data obtained by all the first gas concentration sensors, plot the corresponding volatile gas concentration-time curve and conduct real-time monitoring.

3. The spontaneous combustion early warning method for coal piles combining real-time monitoring and spontaneous combustion simulation according to claim 2, characterized in that In Step S12, if the real-time temperature monitoring data corresponding to a certain moment exceeds the temperature monitoring threshold, a risk warning is issued; Or, if it is inferred from the temperature-time curve that the real-time temperature monitoring data corresponding to a future moment will exceed the temperature monitoring threshold, a risk warning is issued before the inferred future moment; In Step S13, if the real-time humidity monitoring data corresponding to a certain moment exceeds the humidity monitoring threshold, a risk warning is issued; Or, if it is inferred from the humidity-time curve that the real-time humidity monitoring data corresponding to a future moment will exceed the humidity monitoring threshold, a risk warning is issued before the inferred future moment; In Step S14, if the real-time volatile gas concentration monitoring data corresponding to a certain moment exceeds the gas concentration monitoring threshold, a risk warning is issued; Or, if it is inferred from the volatile gas concentration-time curve that the real-time volatile gas concentration monitoring data corresponding to a future moment will exceed the gas concentration monitoring threshold, a risk warning is issued before the inferred future moment.

4. The method for early warning of spontaneous combustion of coal piles combining real-time monitoring and spontaneous combustion simulation according to claim 2 or 3, characterized in that, The specific process of Step S2 includes: Step S21: Construct a hollow simulation stacking skeleton by scaling the outer contour information of the coal pile proportionally, and set a non-woven fabric layer on the simulation stacking skeleton to form a simulation cavity; a bottom opening with a relatively large size is reserved on the simulation cavity. Step S22: Randomly collect coal samples from the coal pile, where the stacking volume of the coal samples is greater than or equal to the volume of the simulation cavity, and manually turn and stir them. Step S23: Turn the simulation cavity so that its open end faces upward, and then load the mixed coal samples into the simulation cavity; meanwhile, during the loading process, a number of electric heating elements are arranged on the divided loading surface, and a second temperature sensor is also provided near each electric heating element; the position of the loading surface corresponds to the position of the monitoring surface in the coal pile, and the position of the electric heating element is arranged with reference to the position of the first temperature sensor; a second humidity sensor and a second gas concentration sensor are also arranged in the simulation cavity; finally, turn the simulation cavity to form the simulation model. Step S24: Obtain the initial temperature, initial humidity, and initial volatile gas concentration of the simulation model by the second temperature sensor, the second humidity sensor, and the second gas concentration sensor respectively; based on the temperature change rate, humidity change rate, and volatile gas concentration change rate calculated from the temperature-time curve, humidity-time curve, and volatile gas concentration-time curve, heat the simulation model, and supplement moisture and volatile gases to simulate the change process of coal stacking, and observe whether the simulation model catches fire and self-ignites.

5. The method for spontaneous combustion warning of coal piles by combining real-time monitoring and spontaneous combustion simulation according to claim 4, characterized in that, The specific process in step S24 includes the following: Step S241: Obtain the initial temperature data, initial humidity data, and initial volatile gas concentration data of the simulation model by the second temperature sensor, the second humidity sensor, and the second gas concentration sensor respectively, and calculate the average value of all the corresponding initial temperature data, initial humidity data, and initial volatile gas concentration data. If the average value of the initial temperature data, the average value of the initial humidity data, and the average value of the initial volatile gas concentration data are all less than or equal to the corresponding real-time temperature monitoring data, real-time humidity monitoring data, and real-time volatile gas concentration monitoring data when the initial stacking of the coal pile is completed, then proceed to the next step. Step S242: Supplement moisture into the simulation model according to the humidity change rate calculated from the humidity-time curve until the humidity monitoring data of the second humidity sensor is equivalent to the average value of the real-time humidity monitoring data of all the first humidity sensors. Step S243: Supplement volatile gases into the simulation model according to the volatile gas concentration change rate calculated from the volatile gas concentration-time curve until the volatile gas concentration data of the second gas concentration sensor is equivalent to the average value of the real-time volatile gas concentration monitoring data of all the first gas concentration sensors. Step S244: Divide the adjacent first temperature sensors on the same monitoring surface into a group and correspond them to one of the electric heating elements on the corresponding filling surface; Based on the average value of the real-time temperature monitoring data obtained by all the first temperature sensors in the same group, plot the temperature-time curve to calculate the temperature change rate, and use the temperature change rate to heat the simulation model with the corresponding electric heating element. The single heating duration is set according to the simulation requirements, or heat the simulation model with the electric heating element until the temperature monitoring data of the corresponding second temperature sensor is the same as the average value of the real-time temperature monitoring data of the first temperature sensors in the corresponding group; Observe whether the simulation model catches fire and self-ignites.

6. The self-ignition warning method for coal piles combining real-time monitoring and self-ignition simulation according to claim 5, characterized in that In step S244, one or more of an infrared thermal imager, an open fire monitor, a smoke sensor, and a carbon dioxide monitor are used for self-ignition monitoring.

7. The spontaneous combustion early warning method for coal piles combining real-time monitoring and spontaneous combustion simulation according to any one of claims 1 to 3 and 5 to 6, characterized in that, Step S3 specifically includes the following processes: Step S31: If the result of real-time monitoring is normal, but the simulated coal pile catches fire and self-ignites, issue a low-frequency self-ignition warning prompt; Step S32: If the result of real-time monitoring is risky, but the simulated coal pile does not catch fire and self-ignite, issue a self-ignition attention prompt; Step S33: If the result of real-time monitoring is risky, and at the same time the simulated coal pile catches fire and self-ignites, issue a high-frequency self-ignition warning prompt.

8. A spontaneous combustion early warning system for coal piles combining real-time monitoring and spontaneous combustion simulation, characterized in that, It includes: First temperature sensors, which are arranged in the coal pile and used to obtain the real-time temperature monitoring data of the coal pile to be monitored since the stacking is completed; Second humidity sensors, which are arranged in the coal pile and used to obtain the real-time humidity monitoring data of the coal pile to be monitored since the stacking is completed; First gas concentration sensors, which are arranged in the coal pile and used to obtain the real-time gas concentration monitoring data of the coal pile to be monitored since the stacking is completed; Simulation cavity, which is scaled proportionally according to the outer contour information of the coal pile, and forms a simulation model after filling with coal samples collected from the coal pile; Electric heating elements, which are arranged in the simulation model; Water supply pipes, the output ends of which are inserted into the simulation model; Gas supply pipes, the output ends of which are inserted into the simulation model; Central processing unit, which is used to plot temperature-time curves, humidity-time curves and volatile gas concentration-time curves and conduct real-time monitoring, and based on the temperature change rate, humidity change rate and volatile gas concentration change rate calculated from the temperature-time curve, humidity-time curve and volatile gas concentration-time curve, respectively control the heating of the simulation model by the electric heating element, the supplement of water by the water supply pipe and the volatile gas by the gas supply pipe.

9. The spontaneous combustion early warning system for coal piles combining real-time monitoring and spontaneous combustion simulation according to claim 8, characterized in that, It also includes: Second temperature sensors, which are arranged near the electric heating elements in the simulation model and correspond to them one by one, and are used to obtain the initial temperature data of the simulation model and subsequent temperature data; A second humidity sensor, which is arranged inside the simulation model and is used to obtain the initial humidity data of the simulation model and subsequent humidity data; A second gas concentration sensor, which is arranged inside the simulation model and is used to obtain the initial gas concentration data of the simulation model and subsequent gas concentration data.

10. The spontaneous combustion early warning system for coal piles combining real-time monitoring and spontaneous combustion simulation according to claim 8 or 9, characterized in that, It further includes: A spontaneous combustion monitoring device, which adopts one or more of an infrared thermal imager, an open fire monitor, a smoke sensor and a carbon dioxide monitor.

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