A risk monitoring system for mine safety production

Abstract

This invention relates to the field of mine safety detection technology, and more particularly to a risk monitoring system for mine safety production. The system includes a screening module, a benchmark module, a determination module, a verification module, a judgment module, an execution module, and a correction module. This invention combines the constraints of electromechanical jamming-induced heat and load spatial propagation, while simultaneously screening suspected source points based on causal continuity and force transmission, eliminating local transient impacts. Furthermore, it transforms the physical existence of coal flow into a dual constraint of transport air resistance and heat dissipation thermal resistance, allowing the spatiotemporal verification benchmark to dynamically evolve with belt load. Moreover, the same temperature rise is amplified to a higher risk of thermal retention under the cover of heavy coal flow, and differentiated treatment is applied, achieving spatiotemporal source tracing under variable load transport conditions. Simultaneously, it adaptively compensates for the disturbance of propagation laws caused by flow field distortion at transfer points, thereby achieving physical source tracing and adaptive accurate early warning of mine conveyor belt fires under complex airflow and multi-source interference.

Description

Technical Field

[0001] This invention relates to the field of mine safety detection technology, and in particular to a risk monitoring system for safe production in mines. Background Technology

[0002] Mine belt conveyor systems operate under high loads and continuous operation for extended periods. Smoldering fires caused by roller jamming and friction pose a significant safety hazard to coal mines. Due to the harsh environment of underground roadways, unsteady airflow fluctuations, and multiple sources of interference such as brief coal-gangue friction and localized overall temperature increases, traditional monitoring systems based on single-point temperature or smoke thresholds are prone to false alarms due to isolated exceedances. Furthermore, they struggle to identify early-stage smoldering fires where heat has accumulated internally and not yet broken through the outer shell, leading to missed detection risks.

[0003] Chinese Patent Application Publication No. CN120526521A discloses an early identification and warning system for conveyor belt fires based on multi-source information. The system includes: a mutation detection module that, based on monitoring points along the conveyor belt in a coal mine area, analyzes the temperature change amplitude within a monitoring period, compares the smoke parameters with the previous period, determines abnormal gas parameter fluctuations, analyzes image feature changes, calculates load fluctuation intervals, identifies drastic changes in heat source temperature difference, and obtains abnormal parameter combination features; a synchronization analysis module that, based on abnormal parameter combination features, determines temperature fluctuation intervals, analyzes extreme change sequences, compares the response times of smoke and gas parameters, identifies key synchronous fluctuation parameters, calculates parameter synchronization amplitude, and obtains a synchronous response feature group; a spatial trend identification module that, based on the synchronous response feature group, analyzes the rate of temperature change at monitoring points, compares the direction of smoke and gas parameter changes in space, determines spatial consistency, calculates the persistence of changes at adjacent points, identifies continuous spatial anomalies, and obtains a continuous spatial offset identifier; and a coupled fluctuation screening module that, based on the continuous spatial offset identifier, compares the load parameter and heat source temperature difference change curves, determines the synchronicity of parameter changes, identifies drastic fluctuation monitoring points, and obtains the load-thermal difference coupling region.

[0004] Therefore, the early identification and warning system for conveyor belt fires based on multi-source information has the following problems: First, the system detects fires based on the magnitude and synchronicity of parameter changes, without separating the influence of the environmental common-mode temperature rise component and local transient friction. When faced with the overall temperature rise of the roadway or large-area coal dust disturbance, it is very easy to generate false alarms due to the synchronous change of multiple parameters. Second, the system uses rigid time-series comparison logic to judge spatial continuity, but the actual fire characteristics have uncertainties in the transportation time. Summary of the Invention

[0005] To address this, the present invention provides a risk monitoring system for safe production in mines, which overcomes the problems in existing technologies, such as the lack of spatiotemporal physical correlation and anti-interference resolution capabilities due to the complex airflow and multi-source interference environment in mines, which leads to the easy underreporting of real smoldering fires and frequent false alarms of transient interference, through multi-dimensional correlation verification and dynamic adaptive adjustment of temperature rise deviation and spatiotemporal migration characteristics.

[0006] To achieve the above objectives, the present invention provides a risk monitoring system for safe production in mines, comprising: The screening module is used to identify several suspected source points based on the duration and load diffusion degree. The duration is determined based on the temperature rise deviation value and idler resistance index of each idler monitoring point obtained in real time during the belt idler fire monitoring process. The idler resistance index and load diffusion degree are determined based on the belt tension and idler speed obtained in real time. The reference module is used to determine the migration reference duration based on the transport coupling wind speed and the real-time acquisition of the along-band transmission distance of the adjacent suspected source points, wherein the transport coupling wind speed is determined based on the downstream confluence velocity and the coal flow coverage. The determination module is used to determine a number of candidate source points and a number of false alarm points based on migration time difference and propagation delay, wherein the migration time difference is determined based on the timestamps of adjacent suspected source points, and the propagation delay is determined based on the migration reference duration. The verification module is used to determine the ignition point or the false alarm point based on the trend correlation, wherein the trend correlation is determined based on the temporal characteristics of the temperature rise deviation values ​​of adjacent candidate source points; The determination module is used to determine the fire source risk level based on the heat retention degree value, wherein the heat retention degree value is determined based on the temperature rise deviation value of the ignition origin, the coal flow coverage rate, and the coal seam thickness. An execution module is used to implement differentiated response measures based on the fire source risk level; The correction module is used to correct the propagation delay based on the transfer point status, wherein the transfer point status is determined based on the opening and closing status of the guide chute at the transfer point and the induced wind status at the transfer point.

[0007] Furthermore, the filtering module includes: The rotational speed determination unit is used to determine the relative rate of decrease in rotational speed based on the idler roller rotational speed and the idler roller rated rotational speed; A tension determination unit is used to determine the relative rate of increase of tension based on the belt tension and the no-load reference tension. A resistance index determination unit, which is connected to the rotational speed determination unit and the tension determination unit respectively, is used to determine the idler roller resistance index based on the relative rate of decrease in rotational speed and the relative rate of increase in tension; A duration determination unit, which is connected to the resistance index determination unit, is used to determine the duration based on the idler roller resistance index and the temperature rise deviation value. A load diffusion determination unit, which is connected to the speed determination unit and the tension determination unit respectively, is used to determine the degree of load diffusion based on the relative decrease rate of speed and the relative increase rate of tension detected by adjacent idler rollers; A screening unit, which is connected to the duration determination unit and the load diffusion determination unit respectively, is used to determine the suspected source point based on the comparison result of the duration and the preset duration threshold, and the comparison result of the load diffusion degree and the preset diffusion threshold.

[0008] Furthermore, the duration determination unit includes: The jamming determination subunit is used to output a mechanical jamming signal based on the comparison result between the idler roller jamming index and the preset jamming threshold. A heat accumulation response subunit, which is connected to the jamming determination subunit, is used to respond to the mechanical jamming signal and output a heat accumulation signal based on the comparison result between the temperature rise deviation value and the preset deviation threshold. A timing subunit, connected to the heat accumulation response subunit, is used to respond to the heat accumulation signal, accumulate the duration of the heat accumulation signal, and obtain the duration.

[0009] Furthermore, the load diffusion determination unit includes: A speed gradient determination subunit is used to determine the speed diffusion gradient based on the relative rate of decrease in speed of the idler monitoring points adjacent to the idler monitoring point; Tension gradient determination subunit, which is used to determine the tension diffusion gradient based on the relative rate of increase of tension of the idler monitoring points adjacent to the idler monitoring point; The load diffusion determination subunit is connected to the speed gradient determination subunit and the tension gradient determination subunit respectively, and is used to determine the degree of load diffusion based on the speed diffusion gradient and the tension diffusion gradient.

[0010] Furthermore, the reference module includes: The smooth flow coefficient determination unit is used to determine the coal flow coverage rate based on the cross-sectional area of ​​the coal flow and the effective carrying area of ​​the conveyor belt, and to determine the airflow smooth flow coefficient based on the numerical characteristics of the coal flow coverage rate. A composite wind speed determination unit is used to determine the downstream composite velocity based on the wind speed in the roadway and the belt conveyor speed. A coupling wind speed determination unit is connected to the smooth flow coefficient determination unit and the combined wind speed determination unit respectively, and is used to determine the transport coupling wind speed based on the smooth flow coefficient and the downstream combined velocity; A duration determination unit, which is connected to the coupling wind speed determination unit, is used to determine the migration reference duration based on the along-band transmission distance and the transport coupling wind speed.

[0011] Furthermore, the determining module includes: The time difference determination unit is used to determine the migration time difference based on the timestamps of two adjacent suspected source points; A delay generation unit is used to determine the propagation delay based on the migration reference duration and the preset fault tolerance margin; The determination unit is connected to the time difference determination unit and the time delay generation unit respectively, and is used to determine the suspected source point as a candidate source point when the migration time difference is less than the propagation time delay, and to determine the suspected source point as a false alarm point when the migration time difference is greater than or equal to the propagation time delay.

[0012] Furthermore, the verification module includes: An extraction unit is used to extract the temperature rise change curves of two adjacent candidate source points based on the temperature rise deviation value. A correlation determination unit, connected to the extraction unit, is used to calculate the cosine similarity of the temperature rise change curves of two adjacent candidate source points to obtain the trend correlation. A verification unit, connected to the correlation determination unit, is used to determine the upstream candidate source point as the ignition origin and the downstream candidate source point as a false alarm point when the trend correlation is greater than or equal to a preset correlation threshold; and to determine both candidate source points as the ignition origin when the trend correlation is less than the preset correlation threshold.

[0013] Furthermore, the determination module includes: Thickness determination unit, which is used to determine the coal seam thickness based on the coal flow profile height; A heat retention determination unit, connected to the thickness determination unit, is used to determine the degree of heat retention based on the temperature rise deviation value, the coal flow coverage rate, and the coal seam thickness. The risk assessment unit, connected to the heat retention determination unit, is used to determine the fire source risk level based on the heat retention degree value. Furthermore, the thermal retention determination unit includes: The relative thickness determination subunit is used to determine the relative thickness based on the coal seam thickness and the preset reference thickness; A shielding degree determination subunit, which is connected to the relative thickness determination subunit, is used to determine the overall shielding degree of the coal flow based on the coal flow coverage rate and the relative thickness; A heat retention determination subunit, which is connected to the shielding degree determination subunit, is used to determine the heat retention degree value based on the temperature rise deviation value and the overall shielding degree of the coal flow.

[0014] Furthermore, the correction module includes: The transfer status acquisition unit is used to acquire the status of the baffle of the transfer point guide chute and the operating status of the transfer point induction fan; A delay correction unit, connected to the transfer status acquisition unit, is used to correct the propagation delay based on the status of the transfer point guide chute baffle and the operating status of the transfer point induction fan.

[0015] Compared with existing technologies, the beneficial effects of this invention are that, in the case of electromechanical transients and coal flow obscuring during the monitoring of fires on conveyor belt idlers, the combined constraint of electromechanical jamming and heat generation and load spatial spread means that the screening of suspected source points must simultaneously satisfy the causal continuity in the time dimension and the force transmission in the spatial dimension. This allows for the precise separation of real and continuous jamming from local transient impacts. Furthermore, the physical existence of coal flow is transformed into a dual constraint of transport wind resistance and heat dissipation thermal resistance, causing the spatiotemporal verification benchmark to dynamically evolve with the belt load. Moreover, the same temperature rise is amplified to a higher risk of thermal retention under the obscuring of heavy coal flow, achieving precise spatiotemporal tracing under variable load transport conditions and matching differentiated treatment. At the same time, adaptive compensation is performed for the disturbance of the propagation law caused by the flow field distortion at the transfer point. Thus, physical tracing and adaptive precise early warning of mine conveyor belt fires under complex airflow and multi-source interference are achieved. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the risk monitoring system used for safe production in mines according to this embodiment; Figure 2 This is a logic diagram for determining suspected source points in the screening module of this embodiment; Figure 3 This embodiment defines the logic diagram for determining candidate source points and false alarm points in the module. Figure 4 This is a logic diagram for determining the ignition point or false alarm point of the verification unit in this embodiment. Detailed Implementation

[0017] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0018] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0019] Please see Figure 1As shown, this is a schematic diagram of a risk monitoring system for mine safety production according to this embodiment. This embodiment provides a risk monitoring system for mine safety production, including: The screening module is used to identify several suspected source points based on the duration and load diffusion degree, in order to filter out non-spreading transient anomalies caused by local instantaneous impact or brief slippage, and to anchor the potential fire hazard points with the dual physical characteristics of continuous heat accumulation and spatial load diffusion. The duration is determined based on the temperature rise deviation value and idler resistance index of each idler monitoring point obtained in real time during the belt idler fire monitoring process. The idler resistance index and load diffusion degree are determined based on the belt tension and idler speed obtained in real time.

[0020] In this embodiment, the temperature rise deviation value is obtained based on the data acquisition module, which includes a temperature acquisition unit and a temperature rise deviation calculation unit. Temperature acquisition unit, which is used to acquire the temperature of the roller bearing internal measuring point collected by the thermocouple sensor installed close to the outer ring of the bearing and the temperature of the roller surface measuring point collected by the thermocouple installed close to the inner surface of the roller skin. The temperature rise deviation calculation unit is used to calculate the difference between the temperature of the measuring point inside the roller bearing and the temperature of the measuring point on the surface of the roller shell, so as to obtain the temperature rise deviation value and eliminate the common mode temperature rise component caused by the overall temperature rise of the roadway environment.

[0021] In this embodiment, the belt tension and idler speed are acquired based on a data acquisition module, which further includes an idler speed acquisition unit and a belt tension acquisition unit. The idler roller speed acquisition unit is used to acquire the idler roller speed in real time from the Hall speed sensor installed on the idler roller end shaft; The belt tension change acquisition unit is used to acquire the belt tension in real time from the tension sensor installed at the tension wire rope of the automatic belt tensioning device.

[0022] The reference module is used to determine the migration reference time based on the transport coupling wind speed and the real-time acquired along-belt transmission distance, so as to determine the theoretical time reference for the downstream transmission of hot smoke characteristics. The transport coupling wind speed is determined based on the downstream combined velocity and the coal flow coverage. In this embodiment, the distance is obtained along the transmission distance using a data acquisition module, which further includes a distance acquisition unit. The distance acquisition unit is used to obtain the cumulative path length along the belt conveyor direction of two adjacent suspected source points as indicated by the preset roadway layout map in the monitoring system, and to obtain the transmission distance along the belt.

[0023] The determination module is used to identify several candidate source points and several false alarm points based on migration time difference and propagation delay, in order to verify whether adjacent triggering events meet the physical constraints of downstream transport, and to isolate non-homogeneous independent concurrent anomalies that lack causal correlation. The migration time difference is determined based on the timestamps of two adjacent suspected source points, and the propagation delay is determined based on the migration reference duration.

[0024] In this embodiment, the timestamp is obtained based on the data acquisition module, which further includes a time acquisition unit. The time acquisition unit is used to obtain the time point when each idler roller monitoring point is identified as a suspected source point, and obtain a timestamp.

[0025] The verification module is used to determine the ignition origin or false alarm point based on trend correlation, so as to eliminate the spatiotemporal coincidence misjudgment caused by non-homogeneous accidental events and accurately locate the ignition origin. The trend correlation is determined based on the temporal characteristics of the temperature rise deviation values ​​of two adjacent candidate source points.

[0026] The determination module is used to determine the fire source risk level based on the heat retention degree value, which is determined based on the temperature rise deviation value of the ignition origin, the coal flow coverage rate, and the coal seam thickness.

[0027] The execution module is used to implement differentiated treatment measures based on the fire source risk level, in order to match the intervention intensity with the thermodynamic constraints under coal flow shielding.

[0028] The correction module is used to correct the preset propagation delay based on the transfer point status, so that the spatiotemporal verification window can dynamically adapt to local flow field distortion. The transfer point status is determined based on the opening and closing status of the feed chute at the transfer point and the induced wind status at the transfer point.

[0029] In the process of monitoring fires on conveyor belt idlers, under the conditions of electromechanical transients and coal flow obscuring the fire, the combined constraints of electromechanical jamming and heat generation and load spatial spread mean that the screening of suspected source points must simultaneously satisfy the causal continuity in the time dimension and the force transmission in the spatial dimension. This allows for the precise separation of real and continuous jamming from local transient impacts. Furthermore, the physical existence of coal flow is transformed into a dual constraint of transport wind resistance and heat dissipation thermal resistance, causing the spatiotemporal verification benchmark to dynamically evolve with the belt load. Moreover, the same temperature rise is amplified to a higher risk of thermal retention under the obscuring of heavy coal flow, enabling precise spatiotemporal tracing under variable load transport conditions and matching differentiated treatment. At the same time, adaptive compensation is performed for the disturbance of the propagation law caused by the flow field distortion at the transfer point. Thus, physical tracing and adaptive precise early warning of mine conveyor belt fires under complex airflow and multi-source interference are achieved.

[0030] Please continue reading. Figure 2 As shown, this is the logic diagram for determining suspected source points by the screening module in this embodiment. In this embodiment, the screening module includes: The speed determination unit is used to calculate the relative deviation between the idler roller speed and the rated idler roller speed, obtain the relative speed reduction rate, quantify the degree of rotational attenuation caused by jamming, and eliminate the influence of differences in the magnitude of different base speeds. The tension determination unit is used to calculate the relative deviation between the belt tension and the no-load reference tension, obtain the relative tension rise rate, quantify the degree of tension change caused by the backward transmission of jamming resistance, and eliminate the influence of differences in the reference tension of different belts. The sluggishness index determination unit is connected to the speed determination unit and the tension determination unit respectively. It is used to calculate the product of the relative decrease rate of speed and the relative increase rate of tension to obtain the idler roller sluggishness index, so as to determine the impact of local mechanical jamming on the dual driving load of rotation state and tensioning system. The duration determination unit is connected to the resistance index determination unit to determine the duration based on the idler roller resistance index and the temperature rise deviation value. The load diffusion determination unit, which is connected to the speed determination unit and the tension determination unit respectively, is used to determine the degree of load diffusion based on the relative decrease rate of speed and the relative increase rate of tension detected by adjacent idlers, so as to quantify the comprehensive intensity of the electromechanical coupling load spreading to the adjacent area space, thereby filtering out instantaneous impacts or local slippage interference that only act on a single point. The screening unit is connected to the duration determination unit and the load diffusion determination unit respectively, and is used to determine the idler monitoring point as a suspected source point when the duration is greater than the preset duration threshold and the load diffusion degree is greater than the preset diffusion threshold.

[0031] In this embodiment, the preset duration threshold is determined based on the duration of transient temperature rise deviation caused by transient disturbances in mine roadway airflow and brief contact friction of coal gangue, as well as the minimum time required for the temperature rise deviation to remain stable without falling back when the idler roller bearing jams and causes continuous internal heat accumulation. It is greater than the typical duration of various transient disturbances, while being less than the stable maintenance time of continuous heat accumulation. Thus, while retaining the characteristics of a real continuous heat source, it effectively filters out non-continuous temperature rise fluctuations such as airflow fluctuations and brief mechanical friction.

[0032] In this embodiment, the preset diffusion threshold is determined based on the statistical distribution characteristics of the relative change rate of speed and tension of adjacent idler rollers under normal operation and occasional single-point impact conditions of mine conveyor belts. The transition value between the upper limit of the minor cascading fluctuations caused by occasional interference and the lower limit of the initial spread of continuous jamming is taken to achieve a balance between identifying the spread of the real load space and filtering out local transient interference.

[0033] In this embodiment, the rated speed of the idler roller and the no-load reference tension are inherent values ​​of the mine conveyor belt, which are obtained by reading the equipment parameters provided by the equipment manufacturer.

[0034] Specifically, the filtering units include: The jamming determination subunit is used to output a mechanical jamming signal when the roller jamming index is greater than the preset jamming threshold, so as to determine that the roller has an abnormal drive load that is obstructed from rotating. The heat accumulation response subunit is connected to the jamming determination subunit to respond to the mechanical jamming signal, obtain the temperature rise deviation value during the period when the idler roller is in a state of rotational obstruction, and output the heat accumulation signal when the temperature rise deviation value is greater than the preset deviation threshold to determine the thermodynamic response of the jamming friction heat generation causing the internal heat to be delayed to be conducted outward. The timing subunit, which is connected to the heat accumulation response subunit, is used to respond to the heat accumulation signal and obtain the duration of the cumulative temperature rise deviation value being greater than the preset deviation threshold, so as to determine the coupling duration of the continuous power supply of the jam and the internal heat accumulation.

[0035] In this embodiment, the preset jamming threshold is determined based on the statistical distribution characteristics of the mechanical operating parameters of the mine belt idler under normal operating conditions and jamming conditions. Its value is located in the transition range between the upper limit of the normal operating load fluctuation and the lower limit of the initial jamming load, so as to achieve a balance between filtering out transient load disturbances caused by belt misalignment or uneven coal quantity and identifying early mechanical jamming.

[0036] In this embodiment, the preset deviation threshold is determined based on the statistical characteristics of the internal and external temperature rise deviation of the mine belt idler under normal thermal balance and internal friction heating conditions. The critical inflection point between the normal thermal balance distribution and the initial distribution range of internal heat accumulation is taken to balance the risk of early hidden fire missed and the false alarm triggering caused by normal load temperature rise.

[0037] Specifically, the load diffusion determination unit includes: The rotational speed gradient determination subunit is used to calculate the arithmetic mean of the relative rate of decrease in rotational speed of the idler monitoring point, the upstream adjacent idler monitoring point, and the downstream adjacent idler monitoring point to obtain the rotational speed diffusion gradient. This is used to quantify the average potential of the rotational obstruction effect spreading to the adjacent idlers on both sides. If the adjacent idlers are not affected, the rate of decrease is zero, and the gradient value is extremely low, indicating that the rotational obstruction effect has not spread spatially. If the adjacent idlers both show a significant decrease, the gradient value increases, indicating that the obstruction effect has spread. The tension gradient determination subunit is used to obtain the tension diffusion gradient based on the arithmetic mean of the relative tension rise rates of the idler monitoring point, the upstream adjacent idler monitoring point, and the downstream adjacent idler monitoring point. This is used to quantify the average potential of the tension change effect spreading to both sides. The larger the tension diffusion gradient, the more significant the tension change effect spreads to both sides. A small tension diffusion gradient indicates that the tension change effect has not been spatially transmitted and the adjacent idlers are not affected by tension. The load diffusion determination sub-unit is connected to the speed gradient determination sub-unit and the tension gradient determination sub-unit respectively, and is used to calculate the sum of the speed diffusion gradient and the tension diffusion gradient to obtain the load diffusion degree.

[0038] By coupling the relative changes in rotational speed and tension in a product form to construct the idler roller resistance index, the identification of mechanical jamming must simultaneously satisfy the dual constraints of rotational resistance and sudden tension change. This allows the use of the zero-law of multiplication to eliminate false triggering caused by a single load transient. After the idler roller bearing seizes, dry friction occurs between the inner ring and the shaft, causing the idler roller speed to decrease. Resistance is transmitted backward along the belt, leading to an increase in belt tension. The instantaneous impact of the coal block acts only at a single point, with almost no change in the parameters of adjacent idler rollers, and its diffusion gradient approaches zero. Thus, the mean characteristic of spatial propagation filters out local transient interference. Furthermore, the resistance to idler roller rotation inevitably leads to frictional heat generation, delayed heat conduction from the inside out, and an increase in temperature rise deviation. Ultimately, the true jamming with a mechanical transmission path is identified, and local instantaneous impacts lacking a spatial ripple surface are completely suppressed. This allows the anchoring of suspected source points to be based on the dual physical causality of temporal continuity and spatial propagation.

[0039] Specifically, the benchmark module includes: The unobstructed flow coefficient determination unit is used to calculate the ratio of the cross-sectional area of ​​the coal flow to the effective carrying area of ​​the conveyor belt to obtain the coal flow coverage rate, thereby quantifying the degree of occupancy of the airflow channel by the conveyor belt load. It also calculates the difference between the coal flow coverage rate and the unobstructed flow coefficient to obtain the unobstructed flow coefficient, thereby determining the effective permeability of the airflow channel under coal flow obstruction. The larger the unobstructed flow coefficient, the less coal flow obstruction and the weaker the thermal smoke characteristics are hindered by the airflow. The smaller the unobstructed flow coefficient, the more severe the coal flow obstruction and the stronger the thermal smoke characteristics are hindered by compression. The composite wind speed determination unit is used to calculate the sum of the wind speed in the roadway and the belt running speed to obtain the downstream composite velocity, so as to determine the absolute transport capacity of the superposition of wind power and belt mechanical carrying effect. Among them, the larger the downstream composite velocity, the stronger the wind carrying power and the higher the absolute rate of downstream migration of hot smoke characteristics; the smaller the downstream composite velocity, the weaker the wind carrying power and the lower the absolute rate of downstream migration of hot smoke characteristics. The coupled wind speed determination unit is connected to the smooth flow coefficient determination unit and the combined wind speed determination unit respectively. It is used to calculate the product of the smooth flow coefficient and the downstream combined velocity to obtain the transport coupled wind speed, so as to determine the actual equivalent migration rate of the hot smoke feature under the dual drive of wind flow carrying and the coal flow shielding effect. The larger the transport coupled wind speed, the shorter the theoretical time required for the hot smoke feature to be transported from upstream to downstream; the smaller the transport coupled wind speed, the longer the theoretical time. The duration determination unit, connected to the coupling wind speed determination unit, is used to calculate the ratio of the transmission distance along the belt to the transport coupling wind speed to obtain the migration reference duration. The larger the migration reference duration, the longer the transmission time between upstream and downstream measuring points, and the corresponding increase in propagation delay. The actual migration time difference is more likely to meet the condition of being less than the propagation delay. The smaller the migration reference duration, the shorter the transmission time, and the corresponding decrease in propagation delay. The constraint on the actual migration time difference is more stringent.

[0040] In this embodiment, the coal flow cross-sectional area, effective conveyor belt carrying area, roadway wind speed, and conveyor belt operating speed are acquired based on a data acquisition module. This data acquisition module further includes a cross-sectional area acquisition unit, a carrying area acquisition unit, a wind speed acquisition unit, and a conveyor belt speed acquisition unit. Cross-sectional area acquisition unit, which is used to calculate the cross-sectional area of ​​coal flow based on real-time scanning by a laser profile scanner installed on the upper cover of the conveyor belt; The load-bearing area acquisition unit is used to obtain the maximum load-bearing cross-sectional area preset in the monitoring system based on the belt width parameter and the idler group trough angle parameter, and to obtain the effective load-bearing area of ​​the belt. The wind speed acquisition unit is used to collect the wind speed in the roadway in real time based on the mine wind speed sensor arranged on the downwind side of the idler roller monitoring point. The belt speed acquisition unit is used to acquire the real-time belt running speed output by the mine belt transport monitoring subsystem.

[0041] The belt conveyor delay effect is incorporated into the downstream velocity, and the coal flow shielding effect is converted into an airflow smoothness coefficient. The product of the two is used to construct the transport coupling wind speed. This allows the migration reference time to dynamically evolve with the transport force and shielding resistance, simultaneously compensating for the time difference compression of the belt heat-carrying forward thrust and the time difference extension of the coal flow obstruction, thus avoiding the loss of spatiotemporal matching of the static reference under variable load conditions.

[0042] Please continue reading. Figure 3 As shown, this is the logic diagram for determining candidate source points and false alarm points by the determination module in this embodiment. In this embodiment, the determination module includes: The time difference determination unit is used to calculate the difference in timestamps of two adjacent suspected source points being identified as suspected source points, to obtain the migration time difference, in order to determine the actual time taken for the feature to be transmitted downstream. The larger the migration time difference, the longer the interval between the two triggers, and the more likely it is to exceed the physical transport window. The smaller the migration time difference, the closer the two triggers are, and the more consistent it is with the downstream migration association. The delay generation unit is used to calculate the sum of the migration reference time and the preset fault tolerance margin to obtain the propagation delay, so as to determine the upper limit of the time fluctuation allowed for the downstream transmission of features. The larger the propagation delay, the easier it is to identify the suspected source point as the candidate source point, and the smaller the propagation delay, the stricter the judgment. The determination unit, which is connected to the time difference determination unit and the time delay generation unit respectively, is used to determine the suspected source point as the candidate source point when the migration time difference is less than the propagation time delay, so as to determine the spatiotemporal coherence of the downstream transmission of thermal smoke characteristics. When the migration time difference is greater than or equal to the propagation time delay, the suspected source point is determined as the false alarm point, so as to exclude non-homologous independent concurrent anomalies that lack causal relationship.

[0043] In this embodiment, the preset fault tolerance margin is determined based on the statistical distribution of the characteristic downstream transmission time deviation caused by the unsteady airflow disturbance in the mine roadway. Its value is obtained by calculating the set quantile of the deviation of the actual transmission time from the theoretical reference time based on the historical fluctuation data of the roadway wind speed, so as to achieve a balance between containing the time dispersion caused by airflow pulsation and avoiding the introduction of non-same-source independent interference by the window being too wide.

[0044] The actual triggering migration time difference is verified within the propagation delay constituted by the physical benchmark and fault-tolerant fluctuations, which forces the causal constraints of flow field transport to be applied to the discrete alarm timing. Triggers that meet the constraints are identified as candidate source points due to their spatiotemporal coherence, while triggers that exceed the constraints are separated into independent false alarms because they violate transport laws.

[0045] Please continue reading. Figure 4 As shown, this is the logic diagram for determining the origin of the fire or the false alarm point by the verification module in this embodiment. In this embodiment, the verification module includes: The extraction unit is used to extract the temperature rise deviation value change curve of two adjacent candidate source points within a preset analysis time after the heat accumulation signal is triggered, so as to obtain the temperature rise change curve to characterize the dynamic evolution process of internal heat accumulation. The correlation determination unit, which is connected to the extraction unit, is used to calculate the cosine similarity of the temperature rise change curves of two adjacent candidate source points to obtain the trend correlation, so as to quantify the consistency of the same source dynamic evolution. The larger the trend correlation, the stronger the degree of thermal accumulation process is dominated by the same source thermodynamics, and the smaller the trend correlation, the higher the probability that the thermal accumulation process is driven by independent mechanical state. The verification unit, connected to the correlation determination unit, is used to determine two candidate source points as co-originating events when the trend correlation is greater than or equal to a preset correlation threshold. The upstream candidate source point among two adjacent candidate source points is determined as the ignition origin, and the downstream candidate source point is determined as a false alarm point. When the trend correlation is less than the preset correlation threshold, the two candidate source points are determined to be unrelated, and both candidate source points are determined as the ignition origin.

[0046] In this embodiment, the preset analysis duration is determined based on the establishment time of stable features of temperature rise deviation trend evolution and the minimum feature length required for correlation calculation. Its value must be greater than the minimum sampling period required to filter out sampling noise and meet the directional consistency assessment, and less than the duration to avoid nonlinear distortion caused by crossing the phase transition critical point, so as to fully capture the steady-state trend features of heat accumulation while filtering out transient noise.

[0047] In this embodiment, the preset relevant threshold is determined based on the statistical distribution characteristics of the correlation between the temperature rise deviation trend of adjacent monitoring points along the mine conveyor belt under the downstream spread condition and the independent heating condition. The value is located in the range between the upper limit of the independent heating correlation and the ideal homogeneous spread benchmark, so as to exclude the false correlation of independent heating events while including the trend decay caused by downstream migration.

[0048] By calculating the cosine similarity of the temperature rise curves to construct trend correlation, the comparison logic shields the differences in absolute temperature rise amplitude and focuses on the consistency of evolution direction. High correlation confirms homogeneous spread and locks in a unique upstream ignition point, while low correlation determines independent ignition and retains multiple ignition sources. Thus, dynamic causal constraints are superimposed on temporal continuity constraints, enabling precise tracing of the ignition source location.

[0049] Specifically, the determination module includes: Thickness determination unit, which is used to determine the coal seam thickness based on the coal flow profile height; The heat retention determination unit, which is connected to the thickness determination unit, is used to determine the degree of heat retention based on the temperature rise deviation value, coal flow coverage rate and coal seam thickness, so as to quantify the degree of heat dissipation obstruction and heat accumulation under the constraint of coal flow shielding. The risk assessment unit, which is connected to the heat retention determination unit, is used to determine the fire source risk level based on the heat retention degree value.

[0050] The thermal retention determination unit includes: The relative thickness determination sub-unit is used to calculate the ratio of the coal seam thickness to the preset reference thickness to obtain the relative thickness, so as to eliminate the influence of the absolute thickness order of magnitude under different belt conveyor conditions. The shielding degree determination subunit is connected to the relative thickness determination subunit to calculate the product of coal flow coverage and relative thickness, so as to obtain the comprehensive shielding degree of coal flow and determine the synergistic thermal resistance effect of lateral shielding range and longitudinal coverage depth. The thermal retention determination subunit, which is connected to the shielding degree determination subunit, is used to calculate the product of the temperature rise deviation value and the overall shielding degree of the coal flow to obtain the thermal retention degree value.

[0051] The higher the coal flow coverage and the greater the coal seam thickness, the more difficult it is for the heat from the idler roller to be released into the roadway environment. The internal heat accumulation continues to increase, and the temperature rise deviation reflects the energy supply intensity of the internal heat source. The comprehensive coal flow shielding reflects the physical constraint strength of the coal flow on heat release. The multiplication of the two makes the same temperature rise deviation amplified into a higher heat retention value under the conditions of high coal flow coverage and large coal seam thickness. This allows for precise quantification of the risk of smoldering fire evolution due to the inability of heat to dissipate effectively under coal flow coverage.

[0052] Specifically, the correction module includes: The transfer status acquisition unit is used to acquire the status of the baffle of the transfer point guide chute and the operating status of the transfer point induction fan; The time delay adjustment unit, connected to the transfer status acquisition unit, is used to increase the propagation time delay and widen the propagation time delay window when the guide chute baffle is closed and the induced fan is stopped, as the local turbulence caused by the coal flow falling intensifies and the characteristic downstream transmission time dispersion increases. When the guide chute baffle is open and the induced fan is running, the downstream transport is accelerated and the time dispersion decreases, thus reducing the propagation time delay and tightening the propagation time delay window.

[0053] By incorporating the states of the feed chute and induced draft fan at the transfer point into the dynamic adjustment of propagation delay, the spatiotemporal verification window adaptively evolves with the local flow field characteristics. The window is widened when local turbulence intensifies to accommodate abnormal hysteresis in real fire conditions, and tightened when downstream acceleration occurs to suppress the mixing of non-homogeneous interferences. This overcomes the loss of lock-up in static delay matching at complex ventilation nodes.

[0054] Specifically, the execution module includes: The first execution unit is used to generate early warning prompts and belt deceleration commands based on low-risk conditions, so as to improve the forced heat dissipation conditions of the idler rollers while maintaining production continuity. The second execution unit is used to generate belt deceleration and local fixed-point spraying commands based on the medium-risk state, so as to forcibly intervene in the heat accumulation under the coal flow coverage and prevent the evolution of smoldering fire. The third execution unit is used to generate emergency stop instructions for the conveyor belt and high-volume water spraying throughout the area based on high-risk conditions, in order to cut off fuel supply and extinguish open flame transitions induced by severe heat retention. By matching the intensity of intervention strategies with the heat retention capacity of the coal flow, excessive shutdowns can be avoided when the retention risk is low, and emergency shutdowns can be implemented to suppress the transition of smoldering fire to open fire when the retention risk is high. This achieves dynamic matching between the intensity of the intervention and the degree of heat dissipation obstruction.

[0055] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention; various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A risk monitoring system for safe production in mines, characterized in that, include: The screening module is used to identify several suspected source points based on the duration and load diffusion degree. The duration is determined based on the temperature rise deviation value and idler resistance index of each idler monitoring point obtained in real time during the belt idler fire monitoring process. The idler resistance index and load diffusion degree are determined based on the belt tension and idler speed obtained in real time. The reference module is used to determine the migration reference duration based on the transport coupling wind speed and the real-time acquisition of the along-band transmission distance of the adjacent suspected source points, wherein the transport coupling wind speed is determined based on the downstream confluence velocity and the coal flow coverage. The determination module is used to determine a number of candidate source points and a number of false alarm points based on migration time difference and propagation delay, wherein the migration time difference is determined based on the timestamps of adjacent suspected source points, and the propagation delay is determined based on the migration reference duration. The verification module is used to determine the ignition origin or the false alarm point based on trend correlation, wherein the trend correlation is determined based on the temporal characteristics of the temperature rise deviation values ​​of adjacent candidate source points; The determination module is used to determine the fire source risk level based on the heat retention degree value, wherein the heat retention degree value is determined based on the temperature rise deviation value of the ignition origin, the coal flow coverage rate, and the coal seam thickness. An execution module, which is used to implement differentiated response measures based on the fire source risk level; The correction module is used to correct the propagation delay based on the transfer point status, wherein the transfer point status is determined based on the opening and closing status of the guide chute at the transfer point and the induced wind status at the transfer point.

2. The risk monitoring system for safe production in mines according to claim 1, characterized in that, The filtering module includes: The rotational speed determination unit is used to determine the relative rate of decrease in rotational speed based on the idler roller rotational speed and the idler roller rated rotational speed; A tension determination unit is used to determine the relative rate of increase of tension based on the belt tension and the no-load reference tension. A resistance index determination unit, which is connected to the rotational speed determination unit and the tension determination unit respectively, is used to determine the idler roller resistance index based on the relative rate of decrease in rotational speed and the relative rate of increase in tension; A duration determination unit, which is connected to the resistance index determination unit, is used to determine the duration based on the idler roller resistance index and the temperature rise deviation value. A load diffusion determination unit, which is connected to the speed determination unit and the tension determination unit respectively, is used to determine the degree of load diffusion based on the relative decrease rate of speed and the relative increase rate of tension detected by adjacent idler rollers; A screening unit, which is connected to the duration determination unit and the load diffusion determination unit respectively, is used to determine the suspected source point based on the comparison result of the duration and the preset duration threshold, and the comparison result of the load diffusion degree and the preset diffusion threshold.

3. The risk monitoring system for safe production in mines according to claim 2, characterized in that, The duration determination unit includes: The jamming determination subunit is used to output a mechanical jamming signal based on the comparison result between the idler roller jamming index and the preset jamming threshold. A heat accumulation response subunit, which is connected to the jamming determination subunit, is used to respond to the mechanical jamming signal and output a heat accumulation signal based on the comparison result between the temperature rise deviation value and the preset deviation threshold. A timing subunit, which is connected to the heat accumulation response subunit, is used to respond to the heat accumulation signal, accumulate the duration of the heat accumulation signal, and obtain the duration.

4. The risk monitoring system for safe production in mines according to claim 3, characterized in that, The load diffusion determination unit includes: A speed gradient determination subunit is used to determine the speed diffusion gradient based on the relative rate of decrease of the speed of the idler monitoring points adjacent to the idler monitoring point; Tension gradient determination subunit, which is used to determine the tension diffusion gradient based on the relative rate of increase of tension of the idler monitoring points adjacent to the idler monitoring point; The load diffusion determination subunit is connected to the speed gradient determination subunit and the tension gradient determination subunit respectively, and is used to determine the degree of load diffusion based on the speed diffusion gradient and the tension diffusion gradient.

5. The risk monitoring system for safe production in mines according to claim 4, characterized in that, The reference module includes: The smooth flow coefficient determination unit is used to determine the coal flow coverage rate based on the cross-sectional area of ​​the coal flow and the effective carrying area of ​​the conveyor belt, and to determine the airflow smooth flow coefficient based on the numerical characteristics of the coal flow coverage rate. A composite wind speed determination unit is used to determine the downstream composite velocity based on the wind speed in the roadway and the belt conveyor speed. A coupling wind speed determination unit is connected to the smooth flow coefficient determination unit and the combined wind speed determination unit respectively, and is used to determine the transport coupling wind speed based on the smooth flow coefficient and the downstream combined velocity; A duration determination unit, which is connected to the coupling wind speed determination unit, is used to determine the migration reference duration based on the along-band transmission distance and the transport coupling wind speed.

6. The risk monitoring system for safe production in mines according to claim 5, characterized in that, The determining module includes: The time difference determination unit is used to determine the migration time difference based on the timestamps of two adjacent suspected source points; A delay generation unit is used to determine the propagation delay based on the migration reference duration and the preset fault tolerance margin; The determination unit is connected to the time difference determination unit and the time delay generation unit respectively, and is used to determine the suspected source point as a candidate source point when the migration time difference is less than the propagation time delay, and to determine the suspected source point as a false alarm point when the migration time difference is greater than or equal to the propagation time delay.

7. The risk monitoring system for safe production in mines according to claim 6, characterized in that, The verification module includes: An extraction unit is used to extract the temperature rise change curves of two adjacent candidate source points based on the temperature rise deviation value. A correlation determination unit, connected to the extraction unit, is used to calculate the cosine similarity of the temperature rise change curves of two adjacent candidate source points to obtain the trend correlation. A verification unit, connected to the correlation determination unit, is used to determine the upstream candidate source point as the ignition origin and the downstream candidate source point as a false alarm point when the trend correlation is greater than or equal to a preset correlation threshold; and to determine both candidate source points as the ignition origin when the trend correlation is less than the preset correlation threshold.

8. The risk monitoring system for safe production in mines according to claim 7, characterized in that, The determination module includes: Thickness determination unit, which is used to determine the coal seam thickness based on the coal flow profile height; A heat retention determination unit, which is connected to the thickness determination unit, is used to determine the degree of heat retention based on the temperature rise deviation value, the coal flow coverage rate, and the coal seam thickness. A risk assessment unit, which is connected to the heat retention determination unit, is used to determine the fire source risk level based on the heat retention degree value.

9. The risk monitoring system for safe production in mines according to claim 8, characterized in that, The thermal retention determination unit includes: The relative thickness determination subunit is used to determine the relative thickness based on the coal seam thickness and the preset reference thickness; A shielding degree determination subunit, which is connected to the relative thickness determination subunit, is used to determine the overall shielding degree of the coal flow based on the coal flow coverage rate and the relative thickness; A heat retention determination subunit, which is connected to the shielding degree determination subunit, is used to determine the heat retention degree value based on the temperature rise deviation value and the overall shielding degree of the coal flow.

10. The risk monitoring system for safe production in mines according to claim 9, characterized in that, The correction module includes: The transfer status acquisition unit is used to acquire the status of the baffle of the transfer point guide chute and the operating status of the transfer point induction fan; A delay correction unit, connected to the transfer status acquisition unit, is used to correct the propagation delay based on the status of the transfer point guide chute baffle and the operating status of the transfer point induction fan.

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