Intelligent control method for multi-zone ventilation in complex goaf

Abstract

The present invention relates to the field of mine ventilation technology, specifically to a multi-area ventilation intelligent control method for complex goaf areas, comprising the following steps: based on the goaf ventilation field survey data, calibrating the economic indicators and ventilation efficiency of existing ventilation technologies, recording existing underground data, and evaluating the ventilation efficiency based on the existing data to generate a ventilation efficiency baseline. In the present invention, the mine ventilation system is optimized by using digital simulation and computer simulation to meet the specific needs of different mining areas, and the air leakage problem in the shallow goaf is reasonably blocked and guided, reducing the backflow of blasting smoke, increasing the effective air volume of the mine, ensuring the safe production of the mine, and making the fan operation efficiency of the mine area reach 79.7% and 75.9% respectively, realizing the energy-saving and efficient operation of the mine ventilation system, introducing the intelligent ventilation remote control system, reducing the safety hazards of manual operation and blasting smoke poisoning, and enhancing the safety management of underground large-scale blasting operations.

Description

Technical Field

[0001] The invention relates to the technical field of mine ventilation, and in particular to an intelligent control method for multi-zone ventilation in a complex goaf. Background Art

[0002] Mine ventilation technology is a vital part of mining engineering. Its main purpose is to provide enough fresh air to the workers in the mine and remove harmful gases, dust, heat and other harmful substances from the mine to ensure the safety and health of the working environment. This technology involves the design, construction and maintenance of mine ventilation networks, including natural ventilation and mechanical ventilation. Natural ventilation relies on natural forces such as wind and air pressure difference to achieve air flow, while mechanical ventilation requires the use of fans, wind tubes and other equipment to force air delivery.

[0003] Among them, the intelligent control method of multi-zone ventilation in complex goaf areas focuses on how to implement efficient and intelligent ventilation control in multiple goaf areas to ensure that each area can get appropriate fresh air supply. Its main purpose is to optimize the air circulation in the mine, reduce the risk of harmful gas accumulation, and improve the mine's operational safety and work efficiency.

[0004] Existing technologies face many challenges in ventilation management in multiple mining areas. In particular, it is difficult to achieve reasonable ventilation distribution without a unified and efficient ventilation system, which affects ventilation quality and safe production. Large-scale air leakage in shallow goafs causes great interference to the mine ventilation system, often leading to backflow of blasting smoke, making it difficult to achieve normal and efficient ventilation, affecting mine safety production. In addition, underground medium and deep hole large-scale blasting ventilation relies on manual inspection and manual start and stop of fans. A large amount of manual operation poses a safety hazard of blasting smoke poisoning. Changes in environmental protection policies have resulted in the inability to implement anti-freezing measures for the original coal-fired hot blast furnace in the mine. New auxiliary shafts and other vertical shafts will freeze during the winter, posing certain safety hazards. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an intelligent control method for multi-zone ventilation in complex goaf areas.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a multi-zone ventilation intelligent control method for complex goaf areas, comprising the following steps:

[0007] S1: Based on the field survey data of goaf ventilation, calibrate the economic indicators and ventilation efficiency of the existing ventilation technology, record the existing underground data, and evaluate the ventilation efficiency based on the existing data to generate a ventilation efficiency baseline;

[0008] S2: Based on the ventilation efficiency baseline, a three-dimensional ventilation dynamic simulation model of the mountain-draining building is established using Ventsim software, a thermal simulation of the natural wind pressure of the mine is performed, the wind pressure changes under climatic conditions are analyzed, and the ventilation path and wind pressure distribution are optimized to generate a ventilation optimization network diagram;

[0009] S3: Based on the ventilation optimization network diagram, the total required air volume of the mine is calculated and analyzed, and independent zoning ventilation schemes for two mining areas are designed. The schemes are simulated using Ventsim software to generate independent ventilation configurations;

[0010] S4: Based on the independent ventilation configuration, for key ventilation nodes, determine various types of ventilation structures and deployment locations, establish a management ledger for the ventilation system, and record multi-node information to generate ventilation node information;

[0011] S5: Based on the ventilation node information, ventilation monitoring points and communication lines are arranged in key operation areas, multiple parameters underground are acquired in real time, and equipment start and stop and motor temperature monitoring are performed according to the operation status, and a ventilation monitoring instruction set is generated;

[0012] S6: Based on the ventilation monitoring instruction set, the wellbore is divided into antifreeze levels according to the degree of icing hazard of the wellbore, antifreeze measures are formulated according to the antifreeze needs of the wellbore, and field tests are carried out to evaluate the antifreeze effect and generate wellbore antifreeze test results.

[0013] As a further scheme of the present invention, the ventilation efficiency baseline includes economic indicators, efficiency ratings, and basic ventilation parameters; the ventilation optimization network diagram includes ventilation dynamic analysis results, climate impact assessment results, and path optimization results; the independent ventilation configuration includes air volume demand details, equipment configuration information, and area separation measures; the ventilation node information includes deployment location, structure type, and information recording details; the ventilation monitoring instruction set includes parameter monitoring list, communication line configuration, and operating status feedback results; the wellbore antifreeze test results include antifreeze effect level, measured temperature data, and ice area mapping data.

[0014] As a further solution of the present invention, based on the field survey data of goaf ventilation, the economic indicators and ventilation efficiency of the existing ventilation technology are calibrated, the existing underground data are recorded, and the ventilation efficiency is evaluated based on the existing data. The steps of generating the ventilation efficiency baseline are specifically as follows:

[0015] S101: Based on the on-site investigation data of goaf ventilation, real-time monitoring of underground data, including wind speed, wind pressure, air temperature and CO concentration data of the goaf, and verification of the real-time and accuracy of the data, to generate underground ventilation data;

[0016] S102: performing statistical analysis on the underground ventilation data, calculating the current ventilation efficiency, performing regression analysis on the wind speed and wind pressure data, evaluating the impact on the ventilation efficiency, and obtaining a ventilation efficiency metric;

[0017] S103: Based on the ventilation efficiency metric, evaluate the economy and efficiency of the existing ventilation system, identify inefficient areas, record ventilation points that need to be optimized, and establish a ventilation efficiency baseline.

[0018] As a further solution of the present invention, based on the ventilation efficiency baseline, a three-dimensional ventilation dynamic simulation model of the mountain-draining building is established using Ventsim software, a thermal simulation of the natural wind pressure of the mine is performed, the wind pressure changes under climatic conditions are analyzed, and the ventilation path and wind pressure distribution are optimized. The steps of generating a ventilation optimization network diagram are specifically as follows:

[0019] S201: Based on the ventilation efficiency baseline, the underground structure data and climate conditions are input into the Ventsim software to construct a three-dimensional ventilation dynamic model, and the wind pressure inside the mine is simulated to generate an underground ventilation model;

[0020] S202: Based on the underground ventilation model, simulate the influence of different seasonal climates on wind pressure, adjust the ventilation path, and analyze the wind pressure data before and after the path adjustment to generate a ventilation efficiency path diagram;

[0021] S203: Based on the ventilation efficiency path diagram, the ventilation dynamic model is adjusted and run in the Ventsim software to check whether the optimized wind pressure meets the expected standard, verify the output effect of the ventilation dynamic model, and obtain the ventilation optimization network diagram.

[0022] As a further solution of the present invention, based on the ventilation optimization network diagram, the total air volume required for the mine is calculated and analyzed, independent zoning ventilation schemes for two mining areas are designed, and the schemes are simulated using Ventsim software. The specific steps of generating independent ventilation configurations are as follows:

[0023] S301: Based on the ventilation optimization network diagram, according to the geographical and climatic conditions of the mining area, quantitatively analyze the air volume requirements of the two mining areas, calculate the total air volume required by the two mining areas respectively, record the analysis data, and generate a zone air volume requirement index;

[0024] S302: Based on the partition air volume demand index, the air volume and path parameters of the two mining areas are set in the Ventsim software, and the accuracy of multiple parameters is verified, the path and air volume are optimized, and the partition ventilation information is generated;

[0025] S303: Based on the partitioned ventilation information, the air volume configuration and path selection of the ventilation dynamic model are adjusted, and the simulation operation process and results are recorded to generate an independent ventilation configuration.

[0026] As a further solution of the present invention, the total required air volume of the mine is calculated using the formula:

[0027]

[0028] In the formula, The air volume required for the mining face is: The air volume required for the standby mining face is: The air volume required for the excavation working face, including development excavation, mining, and cutting, The air volume required for the chamber that requires independent airflow, is the air volume required for other air demanding points, It is the mine air volume reserve coefficient.

[0029] As a further solution of the present invention, the air volume required for the mining face includes blasting ventilation and secondary crushing ventilation, and the blasting ventilation is calculated using the formula:

[0030]

[0031] In the formula, It is ventilation time. is the amount of explosives used in the explosion, is the blasthole outflow coefficient, is the volume of the tunnel filled with blastholes, ,in, is the volume of the exhaust side tunnel, is the total amount of gas produced by 1 kg of explosive;

[0032] The secondary crushing ventilation is calculated using the formula:

[0033]

[0034] In the formula, is the cross-sectional area of ​​the mine tunnel, It is half the length of the mine tunnel. is the amount of explosives consumed in the secondary blasting, is the ventilation time after secondary crushing blasting;

[0035] The required air volume for the excavation working face, spare mining working face and other air demanding points is calculated using the formula:

[0036]

[0037] In the formula, It is ventilation time. is the amount of explosives consumed in one excavation blast. is the cross-sectional area of ​​the tunnel, It is the length of the smoke throwing belt.

[0038] As a further solution of the present invention, based on the independent ventilation configuration, for key ventilation nodes, various types of ventilation structures and deployment locations are determined, a management ledger of the ventilation system is established, and multi-node information is recorded. The steps of generating ventilation node information are specifically as follows:

[0039] S401: Based on the independent ventilation configuration, a ventilation structure type is selected, deployed at a key ventilation node, and the structure specifications and location are recorded to generate a ventilation structure deployment record;

[0040] S402: Based on the ventilation structure deployment record, register the information of each ventilation node in the ventilation management ledger, including the location, type and performance parameters, update the ledger and perform information entry to generate ventilation node management information;

[0041] S403: Based on the ventilation node management information, information of the ventilation nodes is aggregated, operation and maintenance data of each node is recorded, and ventilation node information is generated.

[0042] As a further solution of the present invention, based on the ventilation node information, ventilation monitoring points and communication lines are arranged in key operation areas, multiple parameters underground are obtained in real time, and equipment start and stop and motor temperature monitoring are performed according to the operation status. The steps of generating a ventilation monitoring instruction set are specifically as follows:

[0043] S501: Based on the ventilation node information, select the key operation area location, install wind speed, wind pressure, CO concentration, air temperature and fan motor temperature monitoring equipment, configure the data transmission line, and generate monitoring facility configuration information;

[0044] S502: Based on the monitoring facility configuration information, automatically analyze the monitoring data, adjust the equipment operation status according to the real-time data of the fan motor, execute the start or stop operation of the equipment, and record the temperature change to generate the equipment operation status record;

[0045] S503: Based on the equipment operation status record, analyze the equipment operation record and temperature monitoring results, evaluate the control efficiency of the ventilation equipment, organize and store the control operation process, and generate a ventilation monitoring instruction set.

[0046] As a further solution of the present invention, based on the ventilation monitoring instruction set, according to the degree of icing hazard of the wellbore of the Paishan Building, the wellbore is classified into antifreeze levels, antifreeze measures for the wellbore antifreeze requirements are formulated, and field tests are conducted to evaluate the antifreeze effects. The steps for generating the wellbore antifreeze test results are specifically as follows:

[0047] S601: Based on the ventilation monitoring instruction set, analyze the degree of harm of wellbore freezing, perform risk rating on the wellbore, record the environmental conditions and freezing risk of each wellbore, divide the antifreeze level according to the rating results, and generate a wellbore environmental risk index;

[0048] S602: Based on the wellbore environmental risk index, formulate corresponding antifreeze measures for wellbores with different antifreeze levels, adjust the measures, match the target wellbore conditions, and generate antifreeze measure configurations;

[0049] S603: Based on the antifreeze measures configuration, perform an antifreeze test in the current wellbore environment, monitor the test process, and record antifreeze effect data to generate a wellbore antifreeze test result.

[0050] Compared with the prior art, the advantages and positive effects of the present invention are:

[0051] In the present invention, the mine ventilation system is optimized by using digital simulation and computer simulation to meet the specific needs of different mining areas. For the air leakage problem in the shallow goaf area, reasonable blocking and guidance are carried out, the phenomenon of blasting smoke backflow is reduced, the effective air volume of the mine is increased, the safe production of the mine is guaranteed, and the fan operation efficiency of the mine area reaches 79.7% and 75.9% respectively, realizing the energy-saving and efficient operation of the mine ventilation system, introducing the intelligent ventilation remote control system, reducing the safety hazards of manual operation and blasting smoke poisoning, and enhancing the safety management of underground large-scale blasting operations. At the same time, through the comprehensive utilization of air compressor waste heat recovery, combined with low-carbon clean air heating technologies such as air source heat pumps and geothermal preheating, a new type of cascade shaft antifreeze technology is formed to replace the original traditional boiler heating method of the mine, which not only eliminates the safety accident hazards caused by shaft freezing, but also effectively reduces coal consumption, reduces heating costs, forms resource-saving recycling, and realizes digital mine construction, realizes the monitoring and early warning of mine ventilation information, prevents mine ventilation safety accidents before they happen, and ensures the long-term stable operation of the mine ventilation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic diagram of the main steps of the present invention;

[0053] Figure 2 It is a schematic diagram of the refinement of S1 of the present invention;

[0054] Figure 3 It is a schematic diagram of the refinement of S2 of the present invention;

[0055] Figure 4 It is a schematic diagram of the refinement of S3 of the present invention;

[0056] Figure 5 It is a schematic diagram of the refinement of S4 of the present invention;

[0057] Figure 6 It is a detailed schematic diagram of S5 of the present invention;

[0058] Figure 7 It is a detailed schematic diagram of S6 of the present invention;

[0059] Figure 8 It is a schematic diagram of the cross-sectional area;

[0060] Fig. 9 It is a schematic diagram of the three-dimensional model of the ventilation system;

[0061] Fig.10 This is a schematic diagram of the thermal simulation model of the upper mine ventilation system;

[0062] Fig.11 This is a schematic diagram of the thermal simulation model of the ventilation system of Xinmin Mine;

[0063] Fig.12 This is the mine ventilation system management system diagram;

[0064] Fig.13 This is the network architecture diagram of the ventilation online monitoring system. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0066] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions 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 therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0067] Embodiment 1

[0068] See also Figure 1 The present invention provides a technical solution: a method for intelligently controlling multi-zone ventilation in a complex goaf, comprising the following steps:

[0069] S1: Based on the field survey data of goaf ventilation, calibrate the economic indicators and ventilation efficiency of the existing ventilation technology, record the existing underground data, including wind speed, wind pressure, air temperature and CO concentration data, and evaluate the ventilation efficiency based on the existing data to generate a ventilation efficiency baseline;

[0070] S2: Based on the ventilation efficiency baseline, the Ventsim software was used to establish a three-dimensional ventilation dynamic simulation model for the mountain drainage building. According to the geographical location and climatic conditions of the mine, the natural wind pressure of the mine was thermally simulated, the wind pressure changes under climatic conditions were analyzed, and the ventilation path and wind pressure distribution were optimized to generate a ventilation optimization network diagram. Under cold climatic conditions, it was determined that the air leakage in the goaf was in the air intake state, which could make up for the underground air intake. Under hot climatic conditions, the air leakage in the goaf was in the air outlet state, forming a short circuit with the return air shaft, reducing the return air efficiency in the deep middle section.

[0071] S3: Based on the ventilation optimization network diagram, the total air volume required for the mine is calculated and analyzed, and independent zoned ventilation plans for the two mining areas are designed. The plans are simulated using Ventsim software to determine the feasibility of the ventilation plans and the compliance of ventilation indicators, and to generate independent ventilation configurations. The ventilation plan is roughly constructed independently for the two mining areas, and zoned ventilation is carried out as needed within the mining areas. Problems with a single zoned ventilation system will have no impact on the other, and the areas can be adjusted independently.

[0072] For the zoned ventilation scheme, the specific scheme is as follows:

[0073] The main air inlet channel of the upper mining area includes the new auxiliary shaft and the belt shaft, and the main return air channel is the return air shaft and the goaf (in cold season). According to the existing ore body occurrence and production operation arrangement, the upper mining area is divided into three ventilation zones:

[0074] (1) Ventilation Zone 1: The middle section of 125m and above. The production and operation area of ​​this zone is mainly the T8 stope near the main chute. Mining in other middle sections has basically ended, and the main work is backfilling and prospecting. There are many middle sections in this zone, and the mining area is connected from top to bottom and from left to right. Some sections of the main tunnel have collapsed seriously, and personnel and materials cannot enter. The main air intake tunnel of Zone 1 is a belt shaft, and an openable closed air door will be established with the auxiliary shaft. Unless there are special circumstances, the air door is normally closed. The main return air tunnel is the west wind shaft and the goaf (cold season). Auxiliary fans are installed near the return air shaft at the 175m main tunnel to construct a 175m return air central tunnel to lead the poor return air area in the adjacent middle section to this middle section, forming a concentrated return air in this zone;

[0075] (2) Ventilation zone II, the middle section of 25m-100m, has less production operations in this zone, and some of the middle sections have basically stopped operations. There are only ore blocks near the return air shaft and some exploration and mining sites near the pedestrian shaft, which are relatively small in number. The main air intake roadway of zone II is the auxiliary shaft, and the main return air roadway is the west wind shaft and goaf (cold season). Auxiliary fans are installed near the return air shaft at the 50m main roadway, and a 50m return air central roadway is constructed to lead the poor return air area in the adjacent middle section to this middle section, forming a centralized return air in this zone;

[0076] (3) The third ventilation zone, the middle section below 0m, is the main production area with more production operations. The medium and deep hole blasting requires a large amount of air and high ventilation requirements. The ventilation allocation and management are difficult. The main air intake roadway of the third zone is the auxiliary shaft (the air is taken in from the auxiliary shaft in the middle section of 0m, and the air is taken in from the middle section of -25m from the middle section of -145m). The main return air roadway is the west wind shaft. Auxiliary fans are installed near the return air shaft in the main roadway at 0m to construct a 0m return air central roadway, which will lead the poor return air area in the adjacent middle section to this middle section, forming a concentrated return air in this zone.

[0077] At present, the western area of ​​the Xinmin Mine Lifting Shaft is in a short-circuit state. The forced ventilation method has serious ventilation problems and needs to rebuild the ventilation network. There are two options:

[0078] Plan 1: dig a blind shaft from the middle section of 180m to the middle section of 100m at the end of the west main tunnel, and connect it with the middle section of 140m. Install air gates at the stone gates connecting the lifting shaft and each middle section to control the air volume. At that time, the main air flow direction will be lifting shaft → 180m west main tunnel → 180m blind shaft → 140m and 100m west main tunnels → 140m and 100m east main tunnels → mining area → return air shaft.

[0079] Option 2 is to dig an independent return air shaft at the western end to form a complete return air system. By then, the Xinmin mining area will form a standard two-wing diagonal ventilation system. The main air intake shaft includes a hoisting shaft and auxiliary air intake (mainly serving the middle section of 223m and the eastern area of ​​the middle section of 180m). The main return air shaft includes the eastern return air shaft and the western return air shaft.

[0080] The middle section of Xinmin mining area is relatively small, and most of the cross-vein tunnels have been closed. With the operation of the later filling system, the original goaf will be filled and closed. Only the 140m and 100m middle sections need to be supplied with air through blind inclined shafts because the lifting shafts have not extended to this point. The air intake is insufficient. In the later stage, it can be considered to change the air gates of the lifting shafts and the 223m and 180m middle sections to a normally closed state, and use the measure wells to supply air to these two middle sections, so as to send as much air volume as possible from the lifting shafts to the lower 140m and 100m middle sections to increase deep ventilation.

[0081] S4: Based on independent ventilation configuration, for key ventilation nodes, determine various types of ventilation structures and deployment locations, establish a management ledger for the ventilation system, and record multi-node information to generate ventilation node information;

[0082] S5: Based on the ventilation node information, ventilation monitoring points and communication lines are arranged in key operation areas to obtain multiple underground parameters in real time, including wind speed, wind pressure, CO concentration, air temperature and fan motor temperature. Equipment start and stop and motor temperature monitoring are performed according to the operating conditions, and a ventilation monitoring instruction set is generated; the operating conditions specifically refer to the operating status of the return air shaft main fan, the underground auxiliary fan fan, and the automatic remote control damper.

[0083] S6: Based on the ventilation monitoring instruction set, according to the degree of icing hazard in the Paishanlou shaft, different shafts are divided into antifreeze levels, antifreeze measures are formulated for shaft antifreeze needs, and field tests are conducted to evaluate the antifreeze effect and generate shaft antifreeze test results; after the antifreeze levels are divided, it is determined that the auxiliary air inlet channel uses low temperature for airflow preheating, the main air inlet channel of the Xinmin mining area uses air source heat pump for heating, and the Shangpai mining area determines the recovery of air compressor waste heat as the heat source for shaft antifreeze through waste heat resource investigation. The specific heat exchange device is a gravity heat pipe, liquid ammonia is used as the heat pipe working fluid, the heat pipe shell is carbon steel, the outer surface is cast iron, the heat pipe has an outer diameter of 25mm, an inner diameter of 20mm, a wall thickness of 2.5mm, the number of roots is 946, the arrangement is in a sequential row, and the heat transfer area is 132㎡. After the construction is completed, the ventilation system of the mine is measured again to ensure that the ventilation effect indicators meet the technical requirements.

[0084] The ventilation efficiency baseline includes economic indicators, efficiency ratings, and basic ventilation parameters. The ventilation optimization network diagram includes ventilation dynamic analysis results, climate impact assessment results, and path optimization results. Independent ventilation configuration includes air volume demand details, equipment configuration information, and area separation measures. Ventilation node information includes deployment location, structure type, and information recording details. The ventilation monitoring instruction set includes parameter monitoring list, communication line configuration, and operating status feedback results. The shaft antifreeze test results include antifreeze effect level, measured temperature data, and ice area mapping data.

[0085] See also Figure 2 Based on the field survey data of goaf ventilation, the economic indicators and ventilation efficiency of the existing ventilation technology are calibrated, the existing underground data, including wind speed, wind pressure, air temperature and CO concentration data, are recorded, and the ventilation efficiency is evaluated based on the existing data. The specific steps for generating the ventilation efficiency baseline are as follows:

[0086] S101: Based on the on-site investigation data of goaf ventilation, real-time monitoring of underground data, including wind speed, wind pressure, air temperature and CO concentration data of the goaf, and verification of the real-time and accuracy of the data, to generate underground ventilation data;

[0087] The main sensor types for underground mine ventilation monitoring include wind speed sensors, wind pressure sensors, and toxic and harmful gas (CO) and air temperature sensors. In terms of sensor hardware, for example, the ultrasonic vortex wind speed sensor adopts ultrasonic vortex detection technology, and the central processing unit adopts the single-chip microcomputer AT89C52. The basic structure mainly includes ultrasonic transmitting and receiving circuits, digital tube display circuits, signal output circuits, and remote control circuits. The C language is used to implement the main program, frequency measurement subroutine, digital filter subroutine, nonlinear compensation subroutine, signal output subroutine, infrared remote control subroutine and other functional modules. Certain measures are taken in the hardware and software design stage to effectively avoid the interference of various external factors. Another example is an intelligent air volume and pressure monitor, which takes the single-chip microcomputer as the core and is equipped with peripheral components such as sensors, VII, AID, E2PROM buttons, digital tubes and power supplies. It has the advantages of easy transformation, intelligent operation, convenience and speed, and realizes the digital display of air volume and air pressure information collection in the air path, and can be transmitted over long distances.

[0088] S102: Statistically analyze underground ventilation data, calculate current ventilation efficiency, perform regression analysis on wind speed and wind pressure data, evaluate the impact on ventilation efficiency, and obtain ventilation efficiency measurement;

[0089] Any ventilation system can be divided into the following three ventilation sections according to the changes in the physical and chemical properties of the air, the characteristics of the tunnel and the impact on the air flow stability at the air-using location: the air intake section, the air-using section and the return air section. Among them, the air intake section is the part from the air intake shaft mouth (or the bottom of the shaft parking lot) to the lower (upper) parking lot or the entrance of the panel area of ​​the mining area; the air-using section is the part from the lower (upper) parking lot of the mining area to the return air stone gate of the mining area (or the confluence of the return air of the mining area and other return air); the return air section is the part from the return air stone gate of the mining area (or the confluence with other return air) to the wind shaft outlet (or the bottom of the wind shaft). When the cross-sectional area of ​​the tunnel is detected by a steel tape measure or a laser rangefinder, the regular section is detected and calculated according to the corresponding area formula. When detecting irregular sections, first use a steel tape measure or a rangefinder to measure the net width B of the tunnel, then divide the net width of the tunnel into n equal parts, and then detect the height b of each equal division point, and calculate the cross-sectional area according to the following formula: ,like Figure 8 As shown, according to the detection line, the air intake and return air are measured first, then the branch tunnel is measured, and then the air volume of the working surface is measured.

[0090] S103: Based on ventilation efficiency metrics, evaluate the economy and efficiency of the existing ventilation system, identify inefficient areas, record ventilation points that need to be optimized, and establish a ventilation efficiency baseline.

[0091] Ventilation wind measurement records of main nodes of the underground ventilation network of the upper mine

[0092]

[0093] Ventilation wind measurement records of main nodes of underground ventilation network in Xinmin Mine

[0094]

[0095] Calculation of equal-area aperture, equal-area aperture A is:

[0096] or

[0097] Where: Q 总 is the total air volume in the mine, H is the wind pressure, and R is the wind resistance.

[0098]

[0099]

[0100] Mine ventilation resistance grade table

[0101]

[0102] According to the calculation results, the equal-area holes in Xinmin Mine Area are less than 1m2, which means that the mine resistance in Xinmin Mine Area belongs to a large-resistance mine. There is a large short-circuit airflow in the wind path, which makes the whole ventilation system difficult to work. The equal-area holes in Shangpai Mine Area are between 1 and 2m2, and the mine resistance belongs to a medium-resistance mine. However, part of the wind drawn out by the fans in Shangpai Mine Area comes from the wind coming down from the goaf. Therefore, the mine resistance level of the upper mining area is actually a large-resistance mine.

[0103] Air volume evaluation index:

[0104] Effective air volume rate:

[0105]

[0106] Where: Q h is the total air intake of the mine or middle section, Q j It is the total return air volume of the mine or mid-section.

[0107]

[0108]

[0109] Air leakage rate:

[0110]

[0111]

[0112]

[0113] According to the regulations, the effective air volume rate of the mine ventilation system should not be less than 60%. The effective air volume of the upper mine does not meet the requirements. Since the large underground goaf area in the upper mine is connected to the surface, there is a problem of air leakage. Part of the air drawn by the fan comes from the air leakage in the goaf. Therefore, in order to ensure that it is consistent with the actual situation, the air volume calculation of the upper mine needs to be multiplied by the air leakage coefficient. From the calculation results, the effective air volume rate of the Shangpai mining area and the Xinmin mining area is low and the air leakage rate is high. Combined with the phenomenon of insufficient air volume in the deep middle section of the two mining areas, it can be seen that the short circuit and air leakage in the upper middle section are more serious. The occurrence of this phenomenon is related to the fact that a large number of goaf areas underground have not been sealed in time and lack of necessary ventilation structures.

[0114] Fan operation efficiency:

[0115] The fan efficiency is the percentage of the output power of the main fan to the input power, reflecting the working condition, performance and matching of the main fan with the mine ventilation network. The main fan operating efficiency is calculated as follows:

[0116]

[0117] In the formula, H 扇 is the wind pressure of the main fan, Pa, Q 扇 is the air volume of the main fan unit, m³ / s;

[0118] N is the main fan motor input power, kw, is the main fan motor efficiency, is the transmission efficiency.

[0119]

[0120]

[0121] According to regulations, the main fan operating efficiency ≥ 60% is the qualified standard, but the main fan operating efficiency of the upper row mine is less than 50%, and the efficiency of the main fan device of Xinmin Mine is just over 60%. The working efficiency is low, indicating that there are major problems with the main fan and ventilation network.

[0122] According to the "Safety Regulations for Metal and Non-metal Mines", the dust exhaust wind speed is as follows: the chamber-type mine is not less than 0.15m / s, the facing stone mining is not less than 0.06m / s, the tunnel-type mine and the excavation tunnel is not less than 0.25m / s, the electric rake road and the secondary crushing tunnel is not less than 0.5m / s, and the wind speed at the work sites such as the skip chamber and the loading belt road is not less than 0.2m / s. The air volume (speed) qualified rate is the percentage of the number of wind demand points that meet the standard for the measured air volume (speed) to the total number of wind demand points. It reflects whether the air volume or wind speed at the wind demand point meets the needs and whether the air volume distribution is reasonable. The air volume (speed) qualified rate is calculated as follows:

[0123]

[0124] In the formula: n is the number of ventilation points whose air volume (speed) meets the standards or design requirements, z is the total number of ventilation points that require air at the same time. A total of 62 air demanding points in the Shangpai mining area were tested, of which 45 air demanding points had air volume (speed) that met the requirements; 22 air demanding points in the Xinmin mining area, of which 14 air demanding points had air volume (speed) that met the requirements. The qualified rate of air volume (speed) is:

[0125]

[0126]

[0127] The calculation results show that the air volume (speed) of the upper mining area meets the requirements, while the air volume (speed) of the Xinmin mining area does not meet the requirements due to the blockage of the return air shaft in the middle section of +105m underground. The mine ventilation structure is the air flow control facility in the mine ventilation system to ensure that the air flow flows along the route required by production. The ventilation structure includes wind walls, air doors, wind curtains, etc.

[0128] After testing and calculation, the main technical and economic indicators of the current ventilation system are: effective air volume rate of the mine: 54.5% in Shangpai Mine and 66.1% in Xinmin Mine. Air leakage rate: 45.5% in Shangpai Mine and 33.9% in Xinmin Mine. Main fan operation efficiency: 46.33% in Shangpai Mine and 64.56% in Xinmin Mine. Air volume qualification rate at the work site: 72.58% in Shangpai Mine and 63.64% in Xinmin Mine. Both Shangpai Mine and Xinmin Mine have serious air leakage in the ventilation system, low effective air volume rate, and poor ventilation conditions on the working face. Combined with the phenomenon of insufficient air volume in the deep middle section of the two mining areas, it can be seen that the short circuit and air leakage in the upper middle section are more serious. The main reason for this phenomenon is the air leakage in the goaf and the lack of necessary ventilation structures underground.

[0129] See also Figure 3Based on the ventilation efficiency baseline, the Ventsim software was used to establish a three-dimensional ventilation dynamic simulation model of the mountain-draining building. According to the mine's geographical location and climatic conditions, the natural wind pressure of the mine was thermally simulated, the wind pressure changes under climatic conditions were analyzed, and the ventilation path and wind pressure distribution were optimized. The specific steps for generating a ventilation optimization network diagram are as follows:

[0130] S201: Based on the ventilation efficiency baseline, the underground structure data and climate conditions are input into the Ventsim software to build a three-dimensional ventilation dynamic model, simulate the wind pressure inside the mine, and generate an underground ventilation model;

[0131] The mine ventilation system is an auxiliary system based on underground shaft and tunnel engineering. Therefore, the ventilation 3D model must also be simulated and established based on the actual mine shaft and tunnel engineering. The specific steps are as follows:

[0132] (1) Collect the latest mid-section geological plan from the mine production or wind measurement department;

[0133] (2) Electronically vectorize the middle section plan or directly use the existing electronic plan;

[0134] (3) The drawing scale of all geological plan maps of the middle section shall be adjusted to 1:1000;

[0135] (4) Move the middle section geological plane map to the actual coordinates according to the plane map grid line coordinate data, or use the last four digits of the integer part of the coordinate value as the reference coordinates;

[0136] (5) Create layers in the drawing software to draw the center lines of each middle section of the tunnel, and complete the drawing of the main airways in sequence;

[0137] (6) Mark the specific plane positions of the lifting and transportation shaft and the special and temporary ventilation shafts in the plan to facilitate the later creation of vertical tunnel engineering;

[0138] (7) Save the graphic files containing the tunnel centerline data as "*.dxf" format files to facilitate later import into the Ventsim ventilation software.

[0139] The steps to create a 3D model of mine ventilation are as follows:

[0140] (1) Open the Ventsim ventilation simulation software, select the center line of the middle tunnel to be imported, and convert it into a solid tunnel. Enter the elevation value of the middle tunnel in the "Z offset" option;

[0141] (2) Select the "Keep existing air path" option and use method (1) to build the solid model of the air path of each middle horizontal tunnel in turn;

[0142] (3) Manually draw vertical or inclined wind paths based on the relative positions of the main shafts or ventilation shafts and the actual project orientation provided in the geological plan of the middle section;

[0143] (4) Select the "Wind Network Processing Tool" to uniformly bind, simplify or merge adjacent air paths in the entire solid model;

[0144] (5) According to the actual mining project, select the wind path entity model to set the tunnel section type, size parameters and tunnel friction coefficient in batches;

[0145] (6) Set the “end is not closed” for the dead-end tunnel in the air path entity model, and set the “connected to the surface” for the shaft leading to the surface exit;

[0146] (7) Based on the measured results of mine ventilation resistance, set the ventilation resistance parameters of the main tunnels, ventilation structures, fan power and other parameters;

[0147] In addition, in order to more vividly and intuitively reflect the spatial relationship between the main ventilation network and the ground of the mining area, the main reference objects such as the mining area surface model and the ground building model can also be imported into the mine ventilation 3D model. The created 3D model of the ventilation system of the Paishanlou gold mine is as follows: Fig. 9 shown.

[0148] In order to improve the authenticity and reliability of ventilation system simulation, it is necessary to check and verify the established ventilation system model. The specific steps are as follows:

[0149] (1) According to the measured data of the mine ventilation system survey, select the "Engineering Environment" option to set different atmospheric environment parameters to perform mine ventilation simulation calculations under different seasonal conditions;

[0150] (2) Verify and inspect the operating status and ventilation conditions of the existing main and auxiliary fans, and test the actual installation and operation of the fans;

[0151] (3) To ensure the validity and scientificity of the simulation results, all calculation parameters should be fitted multiple times with the current status of mine ventilation;

[0152] (4) Loop detection can detect the dirty air circulation phenomenon in the ventilation system and block the air path in time to prevent the dirty air from circulating again;

[0153] (5) Check each area where air flows through the tunnels one by one, promptly block and isolate unnecessary air flow in the tunnels, simplify the three-dimensional simulation model, and improve the efficiency of network solution.

[0154] S202: Based on the underground ventilation model, simulate the impact of different seasonal climates on wind pressure, adjust the ventilation path, and analyze the wind pressure data before and after the path adjustment to generate a ventilation efficiency path diagram;

[0155] S203: Based on the ventilation efficiency path diagram, the ventilation dynamic model is adjusted and run in the Ventsim software to check whether the optimized wind pressure meets the expected standard, verify the output effect of the ventilation dynamic model, and obtain the ventilation optimization network diagram.

[0156] The simulation parameters are set as follows:

[0157] Mining shaft engineering friction coefficient parameter table

[0158]

[0159] Mine ventilation structure wind resistance parameter table

[0160]

[0161] The Ventsim three-dimensional ventilation dynamic simulation system can perform thermal simulation on the ventilation system. During the thermal simulation, the natural wind pressure of each section of the wind path in the wind network is calculated, and the ventilation parameters such as the volume and resistance of the compressible air flow underground are calculated. The engineering environmental parameters of the ventilation system simulation calculation of the Paishanlou mine, including atmospheric pressure and surface temperature, are measured by on-site investigations and should be adjusted accordingly in the later stage according to the changes in the simulated seasons;

[0162] Table of thermodynamic calculation parameters of natural wind pressure

[0163]

[0164] In addition to the influence of rock temperature, the influence of other heat sources is negligible. The following is a calculation and analysis of the natural wind pressure of the ventilation system optimization scheme under different climatic conditions. Please see Fig.10 , Fig.11 .

[0165] See also Figure 4 Based on the ventilation optimization network diagram, the total air volume required for the mine is calculated and analyzed, and independent zoning ventilation schemes for two mining areas are designed. The schemes are simulated using Ventsim software to determine the feasibility of the ventilation schemes and the compliance of ventilation indicators. The specific steps for generating independent ventilation configurations are as follows:

[0166] S301: Based on the ventilation optimization network diagram and according to the geographical and climatic conditions of the mining area, quantitatively analyze the air volume requirements of the two mining areas, calculate the total air volume required by the two mining areas respectively, record the analysis data, and generate the zone air volume requirement index;

[0167] S302: Based on the zoning air volume demand index, the air volume and path parameters of the two mining areas are set in the Ventsim software, and the accuracy of multiple parameters is verified, and the path and air volume are optimized until the design requirements are met, and the zoning ventilation information is generated;

[0168] S303: Based on the partition ventilation information, adjust the air volume configuration and path selection of the ventilation dynamic model to ensure the consistency of the ventilation indicators with the actual application scenarios, record the simulation operation process and results, and generate an independent ventilation configuration.

[0169] The total air volume required for the mine is calculated using the formula:

[0170]

[0171] In the formula, is the air volume required for the mining face, m³ / s, The air volume required for the standby mining face, m³ / s, The air volume required for the excavation working face, including development excavation, mining and cutting, m³ / s, The air volume required for the chamber that requires independent airflow, such as underground explosives storage, m³ / s, It is the air volume required by other air-demanding points, such as the main chute mine loading and unloading points, m³ / s, It is the mine air volume reserve coefficient.

[0172] Statistics of wind-required operation points are shown in the following table:

[0173] Statistics of wind demand points in Shangpai mining area

[0174]

[0175] Statistics of wind demand points in Xinmin mining area

[0176]

[0177] The underground mining method of the two mining areas of Paishanlou Gold Mine is mainly medium-deep holes, and the mining method is mainly the staged rock drilling and chamber method, which belongs to the large blasting stope. Due to the existence of ore pillars, large blasting stopes are mostly closed stopes. After blasting, a high air pressure is formed inside the stope. Under the action of this pressure, the blastholes flow outward to the return air stope through the skylight, funnel and rake tunnel. Its ventilation process is similar to that of the tunnel-type stope, so it is calculated according to smoke exhaust;

[0178] The air volume required for the mining face includes blasting ventilation and secondary crushing ventilation. The blasting ventilation is calculated using the formula:

[0179]

[0180] In the formula, is the ventilation time / s. The ventilation time after the underground blast at Paishanlou Gold Mine is about 4.5h. is the amount of explosives used in blasting / kg. The amount of explosives consumed in a large blast is 10t. is the blasthole outflow coefficient, which is 0.175. is the volume of the tunnel filled with blastholes / m³, ,in, is the volume of the exhaust side tunnel / m³, It is the total amount of gas produced by 1kg of explosives, which is about 0.9m³.

[0181] V=V1+iAb c =2.7×2.7×40+0.175×10000×0.9=1866.6m 3

[0182]

[0183] Therefore, the air volume required after the large blast in the chamber method stope during the staged rock drilling is 4.5m 3 / s,

[0184] Before the underground mining area of ​​Paishanlou Gold Mine is unloaded, it is necessary to perform secondary crushing on the large pieces dropped by the large explosion. The consumption of explosives for secondary blasting in Shangpai Mining Area is: 170kg for the first shift, 270kg for the second shift, and 170kg for the third shift, and 200kg is taken here; the statistical consumption of explosives for secondary blasting in Xinmin Mining Area is 0.25kg / t, and according to the daily mining output of Xinmin in three shifts of 400t / d, the secondary blasting consumes a total of 100kg of explosives, and the consumption of explosives for a single blasting in each shift is taken as 40kg at most;

[0185] Secondary crushing ventilation is calculated using the formula:

[0186]

[0187] In the formula, is the cross-sectional area of ​​the mine tunnel / m², 2.7×2.7=7.29m 2 , It is half of the length of the mine tunnel / m, here we take 4m, is the amount of explosives consumed in the secondary blasting / kg, is the ventilation time after secondary crushing blasting / s, generally 300s:

[0188] The ventilation volume required after the secondary blasting in the upper mining area is:

[0189]

[0190] The ventilation volume required after the secondary blasting in Xinmin Mining Area is:

[0191]

[0192] Calculate the air volume according to the dust exhaust wind speed:

[0193]

[0194] Where: v is the dust removal wind speed / m / s. The dust removal wind speed required for the tunnel type mining face is 0.15~0.5m / s, here we take 0.5m / s, S is the cross-sectional area of ​​the tunnel / m 2 , 2.7×2.7=7.29m 2 ;

[0195] The required air volume of the excavation working face is calculated based on the dust exhaust wind speed: Q = 0.5 × 7.29 = 3.645m 3 / s;

[0196] Taking the maximum value of the above two, the required air volume for secondary crushing blasting ventilation in the upper mining area is 6.49m 3 / s, the ventilation volume required for secondary crushing blasting in Xinmin Mining Area is 3.645m 3 / s.

[0197] Calculation of total air volume required for the entire mine:

[0198] The underground large-scale blasting in the Shangpai mining area and Xinmin mining area of ​​Paishanlou Gold Mine consumes 10 tons of explosives each time, and only one large-scale blasting is carried out at the same time point. At present, Shangpai Mine has 9 underground tunneling machines (drilling machine model YT-28 drills), 3 of which are in construction for development projects and 6 for construction for mining and approval projects; Xinmin Mine has 7 underground tunneling machines (drilling machine model YT-28 drills), 3 of which are in construction for development projects and 4 for construction for mining and approval projects;

[0199] Statistics of air volume at all air-demanding points in Paishanlou Gold Mine

[0200]

[0201] Considering that the mining method of Paishanlou Gold Mine is mainly open-field method, there is air leakage in the goaf, so the air volume reserve coefficient k=1.35 is taken. Then the total required air volume of the upper mining area is:

[0202]

[0203] The total air volume required in Xinmin Mining Area is:

[0204]

[0205] Air volume verification, verification based on air volume consumed by personnel and equipment:

[0206] Check the air volume required by the maximum number of people working underground at the same time:

[0207] Q=n×Q i

[0208] Where: n is the maximum number of people working at the same time underground. The maximum number of people working at the same time underground in Shangpai Mine is 100, and the maximum number of people working at the same time underground in Xinmin Mine is 45;

[0209] Q i is the per capita air supply, m 3 / min, the general air supply volume should be no less than 4m 3 / min / person, then:

[0210] Q 上排矿区 =100×4=400m 3 / min=6.67m 3 / s;

[0211] Q 新民矿区 =45×4=180m 3 / min=3m 3 / s

[0212] Calculation of air volume required for ventilation of diesel equipment:

[0213] There is only one internal combustion shovel loader used in the underground of Shangpai Mining Area, model TXCY-1, power 50kw; there are two internal combustion shovel loader used in the underground of Xinmin Mining Area, model WJD-1, power 45kw, so the required air volume when using diesel equipment is calculated as follows:

[0214] Q=q0×N

[0215] Where: q0 is the air volume index per unit power / m 3 / s.kw, generally 0.06~0.07m 3 / s.kw, here = 0.07m 3 / skw, N is the power of the diesel equipment / kw.

[0216] but:

[0217]

[0218]

[0219] In summary, the air volume required for the maximum number of people working simultaneously underground in the upper mining area is: Q=6.67+3.5=10.17m 3 / s; The air volume required for the maximum number of people working simultaneously underground in Xinmin Mine is: Q=3+3.15=6.15m 3 / s; The air volume in the two mining areas can fully meet the air volume requirements of the maximum number of people working simultaneously underground.

[0220] Check according to the air consumption of 10,000 tons, and the air consumption of 10,000 tons is calculated as follows:

[0221] Q=YA,m 3 / s

[0222] Where: A is the annual output of the mine / 10,000 tons, Shangpai mining area is 495,000 tons, Xinmin mining area is 132,000 tons, Y is the air consumption per 10,000 tons / m 3 / s·10,000 tons. The Shangpai mine is a large-scale mine, and the air consumption per 10,000 tons is between 1.2 and 3.5, so 1.2 is taken here. The Xinmin mine is a medium-sized mine, and the air consumption per 10,000 tons is between 1.5 and 4.0, so 2.5 is taken here.

[0223] Therefore, the total air volume of the upper mine is estimated based on the air consumption of 10,000 tons: Q = 1.2 × 49.5 = 59.4m 3 / s; the total air volume of Xinmin Mine is: Q=2.5×13.2=33m 3 / s.

[0224] Excavation working face, spare mining working face and others

[0225] The required air volume at the required air point is calculated using the formula:

[0226]

[0227] In the formula, is the ventilation time / s, s is generally taken as 1800s, The amount of explosives consumed in one excavation blasting is 27kg in Shangpai Mining Area and 36kg in Xinmin Mining Area. is the cross-sectional area of ​​the tunnel / m², 2.7×2.7=7.29m², is the length of the smoke throwing belt / m, , the Shangpai mining area is 20.4m, and the Xinmin mining area is 22.2m;

[0228] The required air volume for the excavation working face in the upper mining area is:

[0229]

[0230] The required air volume for the excavation working face in Xinmin Mine is:

[0231]

[0232] Calculate the air volume according to the dust exhaust wind speed:

[0233]

[0234] Where: u—dust exhaust wind speed / m / s, usually not less than 0.25m / s in tunneling, here we take 0.3m / s;

[0235] S—cross-sectional area of ​​tunnel / m2, 2.7×2.7=7.29m2.

[0236] The required air volume of the excavation working face is calculated based on the dust exhaust wind speed: Q=0.3×7.29=2.187m² / s.

[0237] Calculated by dust exhaust air volume:

[0238] The model of underground heading machine in Paishanlou Gold Mine is YT-28. The rock drilling equipment produces relatively large dust. In order to dilute the dust produced by the rock drilling equipment to the allowable concentration, the required air volume should be calculated according to the exhaust air volume of the dust-producing equipment. The dust exhaust air volume of the mining face using a light rock drilling equipment with through-flow ventilation is 3.0m³ / s. The dust exhaust air volume selected in the design is 3.0m³ / s. The maximum value of the above three is taken. Therefore, the required air volume of the underground heading face of Paishanlou Gold Mine is 3m³ / s.

[0239] See also Figure 5 Based on independent ventilation configuration, for key ventilation nodes, determine various types of ventilation structures and deployment locations, establish a management ledger for the ventilation system, and record multi-node information. The specific steps for generating ventilation node information are as follows:

[0240] S401: Based on the independent ventilation configuration, the ventilation structure type is selected, deployed at the location of the key ventilation node, and the structure specifications and location are recorded to generate the ventilation structure deployment record;

[0241] S402: Based on the ventilation structure deployment record, register the information of each ventilation node in the ventilation management ledger, including the location, type and performance parameters, update the ledger and perform information entry to generate ventilation node management information;

[0242] S403: Based on the ventilation node management information, the ventilation node information is aggregated, the operation and maintenance data of each node is recorded, and the ventilation node information is generated.

[0243] The ventilation system should be managed by a dedicated person. The production and technology department and branch mines should arrange dedicated personnel to manage or concurrently manage the mine ventilation system and establish a ventilation management account. For this purpose, it is necessary to have technicians who master the mine ventilation theory and technology. For complex ventilation systems, there should be corresponding management systems for the control of air ducts, the management of ventilation structures, the maintenance of fans, technical files and reports. Mines should be equipped with a certain number of ventilation and dust prevention detection instruments and meters to timely detect and grasp the quality of underground ventilation, such as anemometers, barometers, thermometers and hygrometers, harmful gas anemometers, dust meters, etc. Through ventilation and wind measurement, we can regularly understand and grasp the operation of the system, and carry out targeted management and maintenance;

[0244] There should be a regular inspection system for the changes of various ventilation structures, fans, and airflow routes in the mine. The use of ventilation structures and fans not in accordance with regulations and the arbitrary change of airflow routes should be corrected in time; damaged ventilation and dust prevention facilities should be repaired or updated in time.

[0245] Improve various ventilation system drawings, such as ventilation system diagrams, ventilation system floor plans and various ventilation facility design and installation drawings; various ventilation original records, meeting minutes, technical documents, and various technical data on ventilation should be collected and archived in a timely manner.

[0246] Strengthen the control of natural wind pressure. In the winter and spring seasons when mine ventilation is difficult, especially strengthen the monitoring of the ventilation system. Once the wind reverse or wind turbulence is found, open the relevant dampers in time to reduce the ventilation resistance or increase the local fan to strengthen ventilation. Specific suggestions are as follows: Fig.12 .

[0247] See also Figure 6 Based on the ventilation node information, ventilation monitoring points and communication lines are arranged in key operation areas to obtain multiple underground parameters in real time, including wind speed, wind pressure, CO concentration, air temperature and fan motor temperature, and perform equipment start and stop and motor temperature monitoring according to the operating conditions. The specific steps for generating the ventilation monitoring instruction set are as follows:

[0248] S501: Based on the ventilation node information, select the key operation area location, install wind speed, wind pressure, CO concentration, air temperature and fan motor temperature monitoring equipment, configure the data transmission line, and generate monitoring facility configuration information;

[0249] S502: Based on the monitoring facility configuration information, automatically analyze the monitoring data, adjust the equipment operation status according to the real-time data of the fan motor, execute the equipment start or stop operation, and record the temperature change to generate the equipment operation status record;

[0250] S503: Based on the equipment operation status record, analyze the equipment operation record and temperature monitoring results, evaluate the control efficiency of the ventilation equipment, organize and store the control operation process, and generate a ventilation monitoring instruction set.

[0251] The monitoring content of the underground ventilation online monitoring system mainly includes information such as wind speed, wind pressure, CO concentration, video monitoring and ventilation machinery monitoring.

[0252] (1) Wind speed and wind pressure

[0253] Monitor the wind speed in the middle section of underground production to estimate the air volume, monitor the wind pressure of the main fans to estimate the ventilation resistance of the shafts and tunnels, set warning values ​​for wind pressure and wind speed, and when the sensor data reaches the warning value, the sensor will give an audible and visual alarm on site, and the data will be transmitted to the ground machine room, giving an audible and visual alarm on the central command platform.

[0254] (2) CO concentration

[0255] Underground production mainly adopts the drilling and blasting method. A large amount of gun smoke will be generated during the blasting process, most of which is CO. While the personnel entering the mine carry a certain number of portable gas alarms, they set up CO concentration sensors in the production area and set alarm values. When the CO concentration reaches the alarm value, the portable gas alarm and sensor will sound and light alarm on site, and transmit the data to the ground room to realize sound and light alarm on the central command platform.

[0256] (3) Gas temperature

[0257] Due to the large range and gentle inclination of the ore body in the Paishanlou mining area, the ventilation network lines are long and complex, and the ventilation routes in the deep middle section have not been formed in time, resulting in the increase of gas temperature deep underground. Therefore, an air temperature sensor is installed in the deep middle section to monitor the changes in the underground air temperature in real time. If there is any abnormality, it will be dealt with in time.

[0258] (4) Ventilation machinery monitoring

[0259] The start and stop of the return air shaft main fan, the underground auxiliary fan and the automatic remote control damper are monitored as well as the temperature of the motor. The operating status of the equipment is displayed in real time on the central command platform according to the start and stop sensors installed on the fans. The motor temperature is set with a warning value. When the sensor temperature reaches the warning value, an audible and visual alarm is triggered on site, and the data is transmitted to the ground machine room. An audible and visual alarm is triggered on the central command platform, and relevant personnel make unified arrangements for handling.

[0260] (5) Video surveillance

[0261] Install video surveillance in key areas to ensure the normal operation of ventilation facilities, continuously provide ventilation power, make the air flow along the established route, and prevent the occurrence of ventilation safety accidents.

[0262] (1) Wind speed sensors should be installed in the underground main return airway, return airways in each production section and segment;

[0263] (2) The main fans should be equipped with wind pressure sensors, and the setting of the sensors should comply with the requirements for the measurement point arrangement of the main fan wind pressure in AQ2013.3;

[0264] (3) Main fans, auxiliary fans and local fans should be equipped with start / stop sensors.

[0265] The data is collected through sensors, and the collected signals are transmitted to the base station through 485 cables to collect signals. After analysis and judgment by the processor, instructions are sent to the controller to realize online real-time monitoring of the ventilation system. The field data can be transmitted to the host computer through Ethernet for display. The method of building this business subsystem on the underground comprehensive digital communication platform is: to count all monitoring items and monitoring point locations, to reasonably partition them according to the distance of the measuring points, to set up a set of intelligent data collection substations and communication control units in each partition, and all monitoring parameters in the partition are automatically collected, stored and uploaded by this collection substation. The system topology is as follows Fig.13 ;

[0266] The main control computer of the control system is connected to the PLC control box in the mine, the PLC control box on the surface and the computer through Ethernet and current signal communication network to form a computer communication network, so as to collect ventilation parameters at key points and realize remote centralized start and stop control of fans. The specific monitoring and control functions are as follows:

[0267] 1. Real-time acquisition of underground wind speed, wind pressure, CO concentration, air temperature, main fan (blower) motor temperature and other related technical parameters;

[0268] 2. Monitor and control the mine fans: monitor and display the start and stop status of the fans, control the remote start and stop, remote reversal, local control, automatic overload protection of the fans, and send out a start warning signal before the fans start, etc.;

[0269] 3. All system functions have online help functions and can be completed under the Chinese menu prompts;

[0270] 4. The data of the monitoring system can be displayed on the monitoring host and workstation, and unified reports can also be compiled and printed out;

[0271] 5. In order to ensure that the system configuration and other information are not damaged, only operators with legal authority can perform corresponding operations on the system;

[0272] 6. The system can display the real-time dynamic curves of any number of measured parameters simultaneously through the display; all measured parameters are saved every 5 minutes and can be saved continuously for one year. If there are special circumstances, they can be saved for a longer period of time;

[0273] 7. There is a main menu display in each display mode. The main menu should include parameter setting, page editing, control (remote control) list display, historical record curve display, status diagram, simulation diagram display, printing, query, help, other functions, etc.;

[0274] 8. According to the query time entered, all analog and switch quantities of alarm information, fault information, and abnormal status during the query period will be displayed or printed;

[0275] 9. While the system is collecting real-time data, it can also record, display, analyze, calculate, report over-limit, and report on shifts, days, and months;

[0276] 10. The system has an open data interface to other software platforms. The system has strong self-diagnosis function and human-computer dialogue function, etc.

[0277] See also Figure 7 Based on the ventilation monitoring instruction set, according to the degree of ice hazard of the wellbore in the Paishan Building, different wellbores are divided into antifreeze levels, antifreeze measures are formulated according to the antifreeze needs of the wellbore, and field tests are carried out to evaluate the antifreeze effect. The specific steps for generating the wellbore antifreeze test results are as follows:

[0278] S601: Based on the ventilation monitoring instruction set, analyze the degree of harm of wellbore freezing, conduct risk rating of the wellbore, record the environmental conditions and freezing risk of each wellbore, divide the antifreeze level according to the rating results, and generate the wellbore environmental risk index;

[0279] S602: Based on the wellbore environmental risk index, formulate corresponding antifreeze measures for wellbores with different antifreeze levels, adjust the measures, match the target wellbore conditions, and generate antifreeze measure configurations;

[0280] S603: Based on the antifreeze measures configuration, perform antifreeze test in the current wellbore environment, monitor the test process, and record antifreeze effect data, evaluate the adaptability and effectiveness of each measure, and generate wellbore antifreeze test results.

[0281] Calculation of heating amount for wellbore antifreeze:

[0282] The heating of wellhead air is divided into two parts: basic heating + additional heat loss, where additional heat loss includes the loss of hot air volume from the ventilator, heat dissipation from the hot air transmission channel, and heat loss from the wellhead. Generally, the heat of accessories does not need to be calculated separately. It is generally calculated by multiplying the basic heating by a coefficient. The coefficient value is 1.05 for a closed wellhead room and 1.15 for an unclosed wellhead. The basic heating is the main component of the heating of the inlet air. There is an empirical calculation formula. The total heating Q is calculated as follows:

[0283]

[0284] Where: is the heat loss coefficient. The wellheads of the two mining areas of Paishanlou are both sealed, and the value is 1.05. The designed air intake volume is 33m 3 / s, Xinmin mining area is 50m 3 / s for calculation, is the specific heat of air at constant pressure, which is 1.003KJ / (kg.K), t1 is the temperature of the air before heating, which is -20℃, t h It is the temperature of the air after heating. According to the design specifications, it is taken as 2℃.

[0285] According to the above formula, Q 上排矿区 =1.05×33×1.29×1.003×22=986KJ, Q 新民矿区 =1.05×50×1.29×1.003×22=1494KJ, (As the production capacity of the upper mining area drops significantly, the required air volume also decreases significantly, and it is calculated here as 500t / d);

[0286] According to the heating amount required for shaft antifreeze, Phoenix's enthalpy-increasing low-temperature air source heat pump is selected for air heating. The product model is PASHW600S-PS-A, and its equipment model parameters are shown as follows:

[0287] Air source heat pump model parameters

[0288]

[0289] This type of air source heat pump can heat the outlet water temperature from 5°C to 41°C, then release the heat, and the medium will enter the heat source for heating cycle after cooling. The heat released by the air source heat pump can be calculated using the following formula:

[0290]

[0291] Where: The specific heat capacity of water is 4.2KJ / kg.℃, is the water flow rate of the air source heat pump, 19.9m 3 / h.

[0292] Calculation shows that the heat released by the air source heat pump in 1 hour is: 4.2×19.9×1000×(41-5)=3008880KJ, and the heat released per second is 835.8KJ, which is lower than the heat required for heating the Shangpai mining area (986KJ) and the heat required for heating the Xinmin mining area (1494KJ). It is difficult to meet the needs of the mine by heating the air for wellhead antifreeze by air source heat pump alone. It is necessary to add additional electric heating heaters or other heating devices for assistance. If the electric heating heater shown in 10.2.1 is added, considering the surplus coefficient of 1.1, at least 6 units are required in the Shangpai mining area and 11 units are required in the Xinmin mining area;

[0293] After calculating the heat released by the air source heat pump, it was found that the heat released by the air source heat pump per second is 835.8KJ, which is lower than the heat required for heating the Shangpai mining area (986KJ) and the heat required for heating the Xinmin mining area (1494KJ). A certain number of auxiliary heating devices need to be added to achieve wellhead antifreeze in extreme weather.

[0294] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. An intelligent control method for multi-zone ventilation in complex goaf, characterized in that: The following steps are involved: Based on the field survey data of goaf ventilation, calibrate the economic indicators and ventilation efficiency of existing ventilation technology, record the existing underground data, and evaluate the ventilation efficiency based on the existing data to generate a ventilation efficiency baseline; Based on the ventilation efficiency baseline, the Ventsim software was used to establish a three-dimensional ventilation dynamic simulation model for the mountain-draining building, to perform thermal simulation on the natural wind pressure of the mine, to analyze the wind pressure changes under climatic conditions, to optimize the ventilation path and wind pressure distribution, and to generate a ventilation optimization network diagram; Based on the ventilation optimization network diagram, the total required air volume of the mine is calculated and analyzed, and independent zoned ventilation schemes for two mining areas are designed. The schemes are simulated using Ventsim software to generate independent ventilation configurations; Based on the independent ventilation configuration, for key ventilation nodes, various types of ventilation structures and deployment locations are determined, a management ledger of the ventilation system is established, and multi-node information is recorded to generate ventilation node information; Based on the ventilation node information, ventilation monitoring points and communication lines are arranged in key operation areas to obtain multiple parameters underground in real time, and equipment start and stop and motor temperature monitoring are performed according to the operation status to generate a ventilation monitoring instruction set; Based on the ventilation monitoring instruction set, the antifreeze level of the wellbore is divided according to the degree of icing hazard of the wellbore of the Paishan Building, antifreeze measures are formulated according to the antifreeze needs of the wellbore, and field tests are conducted to evaluate the antifreeze effect and generate wellbore antifreeze test results; The ventilation efficiency baseline includes economic indicators, efficiency ratings, and basic ventilation parameters; the ventilation optimization network diagram includes ventilation dynamic analysis results, climate impact assessment results, and path optimization results; the independent ventilation configuration includes air volume demand details, equipment configuration information, and regional separation measures; the ventilation node information includes deployment locations, structure types, and information recording details; the ventilation monitoring instruction set includes parameter monitoring lists, communication line configurations, and operating status feedback results; the shaft antifreeze test results include antifreeze effect levels, measured temperature data, and icing area mapping data; Based on the ventilation optimization network diagram, the total air volume required for the mine is calculated and analyzed, and independent zoned ventilation schemes for two mining areas are designed. The schemes are simulated using Ventsim software. The specific steps for generating independent ventilation configurations are as follows: Based on the ventilation optimization network diagram, according to the geographical and climatic conditions of the mining area, the air volume requirements of the two mining areas are quantitatively analyzed, the total air volume required by the two mining areas is calculated, and the analysis data is recorded to generate the zone air volume requirement index; Based on the partition air volume demand index, the air volume and path parameters of the two mining areas are set in the Ventsim software, and the accuracy of multiple parameters is verified, the path and air volume are optimized, and the partition ventilation information is generated; Based on the partitioned ventilation information, the air volume configuration and path selection of the ventilation dynamic model are adjusted, and the simulation operation process and results are recorded to generate an independent ventilation configuration.

2. The intelligent control method for multi-zone ventilation in complex goaf according to claim 1 is characterized in that: Based on the field survey data of goaf ventilation, the economic indicators and ventilation efficiency of the existing ventilation technology are calibrated, the existing underground data are recorded, and the ventilation efficiency is evaluated based on the existing data. The specific steps for generating the ventilation efficiency baseline are as follows: Based on the on-site survey data of goaf ventilation, real-time monitoring of underground data, including wind speed, wind pressure, air temperature and CO concentration data in the goaf, and verification of the real-time and accuracy of the data, to generate underground ventilation data; Performing statistical analysis on the underground ventilation data, calculating the current ventilation efficiency, performing regression analysis on the wind speed and wind pressure data, evaluating the impact on the ventilation efficiency, and obtaining a ventilation efficiency metric; Based on the ventilation efficiency metrics, the economy and efficiency of the existing ventilation system are evaluated, inefficient areas are identified, and ventilation points that need to be optimized are recorded to establish a ventilation efficiency baseline.

3. The intelligent control method for multi-zone ventilation in complex goaf according to claim 1 is characterized in that: Based on the ventilation efficiency baseline, the Ventsim software was used to establish a three-dimensional ventilation dynamic simulation model of the mountain-draining building, to perform thermal simulation on the natural wind pressure of the mine, to analyze the wind pressure changes under climatic conditions, and to optimize the ventilation path and wind pressure distribution. The specific steps for generating a ventilation optimization network diagram are as follows: Based on the ventilation efficiency baseline, the underground structure data and climate conditions are input into the Ventsim software to construct a three-dimensional ventilation dynamic model, and the wind pressure inside the mine is simulated to generate an underground ventilation model; Based on the underground ventilation model, the influence of different seasonal climates on wind pressure is simulated, the ventilation path is adjusted, and the wind pressure data before and after the path adjustment is analyzed to generate a ventilation efficiency path diagram; Based on the ventilation efficiency path diagram, the ventilation dynamic model is adjusted and run in the Ventsim software to check whether the optimized wind pressure meets the expected standard, verify the output effect of the ventilation dynamic model, and obtain the ventilation optimization network diagram.

4. The intelligent control method for multi-zone ventilation in complex goaf according to claim 1 is characterized in that: The total required air volume of the mine is calculated using the formula: ； In the formula, The air volume required for the mining face is: The air volume required for the standby mining face is: The air volume required for the excavation working face, including development excavation, mining, and cutting, The air volume required for the chamber that requires independent airflow, is the air volume required for other air demanding points, It is the mine air volume reserve coefficient.

5. The intelligent control method for multi-zone ventilation in complex goaf according to claim 4 is characterized in that: The air volume required for the mining face includes blasting ventilation and secondary crushing ventilation, and the blasting ventilation is calculated using the formula: ； In the formula, It is ventilation time. is the amount of explosives used in the explosion, is the blasthole outflow coefficient, is the volume of the tunnel filled with blastholes, ,in, is the volume of the exhaust side tunnel, is the total amount of gas produced by 1 kg of explosive; The secondary crushing ventilation is calculated using the formula: ； In the formula, is the cross-sectional area of ​​the mine tunnel, It is half the length of the mine tunnel. is the amount of explosives consumed in the secondary blasting, is the ventilation time after secondary crushing blasting; The required air volume for the excavation working face, spare mining working face and other air demanding points is calculated using the formula: ； In the formula, It is ventilation time. is the amount of explosives consumed in one excavation blast. is the cross-sectional area of ​​the tunnel, It is the length of the smoke throwing belt.

6. The intelligent control method for multi-zone ventilation in complex goaf according to claim 1 is characterized in that: Based on the independent ventilation configuration, for key ventilation nodes, various types of ventilation structures and deployment locations are determined, a management ledger of the ventilation system is established, and multi-node information is recorded. The steps for generating ventilation node information are specifically as follows: Based on the independent ventilation configuration, the type of ventilation structure is selected, deployed at the location of the key ventilation node, and the structure specifications and location are recorded to generate a ventilation structure deployment record; Based on the ventilation structure deployment record, register the information of each ventilation node in the ventilation management ledger, including the location, type and performance parameters, update the ledger and perform information entry to generate ventilation node management information; Based on the ventilation node management information, the ventilation node information is summarized, the operation and maintenance data of each node is recorded, and the ventilation node information is generated.

7. The intelligent control method for multi-zone ventilation in complex goaf according to claim 1 is characterized in that: Based on the ventilation node information, ventilation monitoring points and communication lines are arranged in key operation areas to obtain multiple parameters underground in real time, and equipment start and stop and motor temperature monitoring are performed according to the operation status. The steps of generating a ventilation monitoring instruction set are as follows: Based on the ventilation node information, select the key operation area location, install wind speed, wind pressure, CO concentration, air temperature and fan motor temperature monitoring equipment, configure the data transmission line, and generate monitoring facility configuration information; Based on the monitoring facility configuration information, the monitoring data is automatically analyzed, the equipment operation status is adjusted according to the real-time data of the fan motor, the equipment start or stop operation is performed, and the temperature change is recorded to generate the equipment operation status record; Based on the equipment operation status record, the equipment operation record and temperature monitoring results are analyzed, the control efficiency of the ventilation equipment is evaluated, the control operation process is sorted and stored, and a ventilation monitoring instruction set is generated.

8. The intelligent control method for multi-zone ventilation in complex goaf according to claim 1 is characterized in that: Based on the ventilation monitoring instruction set, according to the degree of icing hazard of the wellbore of the Paishan Building, the wellbore is divided into antifreeze levels, antifreeze measures for the wellbore antifreeze requirements are formulated, and field tests are conducted to evaluate the antifreeze effect. The steps for generating the wellbore antifreeze test results are as follows: Based on the ventilation monitoring instruction set, the degree of harm of wellbore freezing is analyzed, the wellbore risk is rated, the environmental conditions and freezing risk of each wellbore are recorded, the antifreeze level is divided according to the rating results, and the wellbore environmental risk index is generated; Based on the wellbore environmental risk index, corresponding antifreeze measures are formulated for wellbores with different antifreeze levels, and the measures are adjusted to match the target wellbore conditions and generate antifreeze measures configuration; Based on the antifreeze measures configuration, an antifreeze test is performed in the current wellbore environment, the test process is monitored, and the antifreeze effect data is recorded to generate the wellbore antifreeze test results.

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