A method for determining a coal face machine head transition coal seam floor

Abstract

The present application belongs to the technical field of underground coal mining, and particularly relates to a method for determining the transition of the coal seam floor at the machine head of a coal mining face. The method comprises the following steps: S100: dividing the machine head section of the coal mining face into a flat section and a transition section, wherein the flat section is a section of the working face connecting the machine head crossheading and the transition section, and the transition section is a section of the working face connecting the flat section and the coal seam floor; S200: simulating the slope of the flat section, wherein the flat section is a sloping surface with a slope, and the length and slope of the flat section are simulated; S300: simulating the slope of the transition section, wherein the slope of the transition section gradually changes from the slope of the flat section to -15 degrees, and then gradually changes from -15 degrees to the slope of the coal seam floor, and the transition section comprises an upper vertical curve and a lower vertical curve; S400: comparing the simulation results of the flat section and the transition section with the actual coal seam detection information, and if the simulation results are consistent with the actual coal seam detection information, the next step is performed, and if the simulation results are not consistent with the actual coal seam detection information, steps S200-S300 are repeated for simulation; and S500: mining the flat section and the transition section according to the simulation results of steps S200-S300.

Description

Technical Field

[0001] This invention belongs to the field of underground coal mining technology, specifically a method for determining the bottom plate of the transition coal seam at the face of a coal mining machine. Background Technology

[0002] Due to the fractured coal seam, only roadways with bottom coal left along the roof can be used in fully mechanized mining faces. It is impossible to achieve roadways with top coal left along the bottom coal of the coal seam. During initial mining, the roadways at the head and tail of the face are affected by the roof layout and need to gradually transition to the floor, resulting in the inability to recover the triangular bottom coal at the head and tail of the face. Taking Chengzhuang Mine, where the applicant is located, as an example, the coal seam thickness is mostly around 6.2 meters, and the height of the two roadways in the high-mining face is 3.8 meters. At the tail section, we use a method of directly lowering the roadway with a step to reduce bottom coal loss. However, the recovery of the triangular bottom coal at the head section can only be done by lowering the roadway along the slope. Because there is no unified standard for the slope of this lowering method, some teams arbitrarily increase and lengthen the length, resulting in serious loss of the triangular bottom coal. Some teams also experience frequent accidents due to improper slope control. Part 6 of the "Basic Requirements and Scoring Methods for Coal Mine Safety Production Standardization (Trial Implementation)" requires that "when the working face inclination angle is greater than 15 degrees, the hydraulic supports should have anti-tipping and anti-slip features." It is evident that the slope should not exceed 15 degrees. However, if the slope is too shallow, the coal at the bottom triangle will be lost.

[0003] Therefore, during the mining process, determining the slope and location of the transition coal seam floor at the mining face head by combining equipment performance and coal seam dip angle can maximize the recovery of bottom triangular coal and effectively reduce triangular coal loss. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a method for determining the bottom plate of the transition coal seam at the head of a coal mining face.

[0005] This invention adopts the following technical solution: a method for determining the bottom plate of the transition coal seam at the head of a coal mining face, comprising the following steps:

[0006] S100: The head section of the coal mining face is divided into a level section and a transition section. The level section is a working face that connects the head roadway and the transition section, and the transition section is a working face that connects the level section and the coal seam floor.

[0007] S200: Perform slope simulation for a flat section. A flat section is a slope with a gradient. Simulate its length and gradient.

[0008] S300: Perform transition section slope simulation. The transition section transitions from the slope of the flat section to -15 degrees, and then from -15 degrees to the slope of the coal seam floor, including two vertical curves, one above the other.

[0009] S400: compare the simulation results of the flat section and the transition section with the actual coal seam detection information, if it is consistent with the actual coal seam detection information, then proceed to the next step, if it is not consistent with the actual coal seam detection information, repeat S200-S300 to simulate.

[0010] S500: according to S200-S300, the simulation results of the flat section and the transition section are mined.

[0011] In some embodiments, in step S200, the length of the flat section is equal to the length of the machine unit, and the maximum slope of the flat section is not more than ±3 degrees.

[0012] In some embodiments, in step S200, the slope is ±3 degrees in the first simulation, and when the simulation results do not match the actual coal seam detection information in S500, the slope is adjusted to be less than ±3 degrees, and the minimum angle of adjustment is 0.1 degrees.

[0013] In some embodiments, in step S300, the transition section is an arc section, and the vertical curve radius corresponding to the arc is wherein

[0014] R is the vertical curve radius;

[0015] L is the length of the chute of the transition section;

[0016] a is the maximum slope angle in the vertical direction of the chute.

[0017] In some embodiments, in step S300, if the first simulation results do not match the actual coal seam detection information in S400, the value of the vertical curve radius R is increased, and the transition section slope is simulated again.

[0018] The value of the vertical curve radius R is increased by less than or equal to 0.5m each time.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] (1) Through this project, a simulation method for the transition of the coal seam floor at the machine head of the roof roadway of a large mining height working face is determined.

[0021] (2) Through this project, the method for the transition of the coal seam floor at the machine head of the large mining height working face under different coal seam inclination angles is standardized, the loss of the bottom triangle coal and the amount of top and bottom waste cutting are reduced, and the occurrence of mechanical and electrical accidents is controlled.

[0022] (3) Through the project, the loss of bottom coal can be easily compared when the working face selects the upward transport and downward transport, in the area where the coal seam inclination of the working face is large, the downward transport arrangement is used as far as possible in the working face, which is very beneficial to the recovery of the bottom triangle coal, for example, when the coal seam inclination is 7 degrees, compared with the upward transport arrangement, the machine head bottom triangle coal loses 169.2 tons of bottom coal and 91.5 tons of top gangue per 1m of advance, and according to the advance of 500m per working face, 84600 tons of bottom coal and 45750 tons of top gangue are saved.

[0023] (4) If the net profit per ton of coal is 200 yuan, 986000 tons of bottom coal can be saved, which can generate economic benefits of 1972 million yuan. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic diagram of slope simulation;

[0025] 1 is a flat section, and 2 is a transition section. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0027] A method for determining the transition coal seam floor of the machine head of a coal mining working face, comprising the following steps,

[0028] S100: The machine head section of the coal mining working face comprises a relatively flat section (generally -3 degrees) and a transition section, wherein the flat section is a section of the working face connecting the machine head crossheading and the transition section, and the transition section is a section of the working face along the coal seam floor.

[0029] S200: The slope of the flat section is simulated, the flat section is a slope surface with a slope, and the length and slope of the flat section are simulated.

[0030] The length and angle of the flat section are related to the machine set and the operation parameters of the working face, the machine head large frame is in the working face crossheading, and is connected with the transshipment machine, the roadway floor is basically horizontal, the machine head large frame is required to be basically horizontal, the maximum slope is not more than ±3 degrees, and the length of the flat section is mainly determined by the length of the machine set. The length of the machine set is generally about 10 frames, in order to prevent accidents caused by directly cutting the roadway roof after the machine set cuts through the coal wall, the maximum slope of the machine head flat section is generally not more than ±3 degrees, and the bottom is found after 10 frames.

[0031] S300: carry out transition section slope simulation, the transition section is from the slope of the flat section to -15 degrees, and then from -15 degrees to the slope of the coal seam floor.

[0032] The transition section is an arc section, and the vertical curve radius corresponding to the arc is wherein

[0033] R is the vertical curve radius;

[0034] L is the length of the chute of the transition section;

[0035] a is the maximum slope angle in the vertical direction of the chute.

[0036] In this embodiment, since the length of one section of the chute is 1.75 meters, the vertical bending of ±1 degree is allowed for every two sections of the chute, and thus the bending vertical curve radius is selected as 35 degrees.

[0037] S400: compare the simulation results of the flat section and the transition section with the actual coal seam detection information, if the simulation results are consistent with the actual coal seam detection information, proceed to the next step, and if the simulation results are not consistent with the actual coal seam detection information, repeat S200-S300 to simulate.

[0038] Draw the simulation results of the machine head section, the flat section and the transition section on the drawing paper of the actual coal seam detection information, and if it is found that the simulation results cannot match the actual coal seam detection information, re-simulate.

[0039] In step S200, ±3 degrees is used for the first simulation, and when the simulation results are compared with the actual coal seam detection information in S400, the slope is adjusted to be less than ±3 degrees, and the minimum angle of adjustment is 0.1 degree.

[0040] In step S300, if the first simulation results are compared with the actual coal seam detection information in S400, the value of the vertical curve radius R is increased, and the transition section slope is re-simulated. The value of the vertical curve radius R is increased by less than or equal to 0.5 m each time.

[0041] S600: carry out coal mining according to the simulation results of the flat section and the transition section in S200-S300. Specific embodiments:

[0043] 4319 large mining height working face adopts "U type" ventilation mode, the west of working face is 43191 roadway (intake airway, electric train roadway), the east is 43193 roadway (intake airway, belt roadway), and 43192 roadway is return airway. The roadway of working face is rectangular section, adopts anchor net support mode, and anchor cable reinforcement is carried out. The roadway section size of working face: the design section size of 43191 roadway is 5.5x3.5m, the design section size of 43193 roadway is 5.5x3.5m, the design section size of 43192 roadway is 5.0x3.8m, the cut hole of 4319 working face is rectangular section with size of 8.5x3.8m, and the section size of belt conveyor head chamber of 4319 working face is 7.7x3.8m.

[0044] Table 1 Simulation situation of transition floor of machine head section of large mining height working face (gate road is arranged along roof)

[0045]

[0046] Coal mining method: the working face adopts longwall large mining height natural caving and retreating type comprehensive mechanized coal mining method. The working face is one time mining of 3# coal with full height, the design mining height of working face is 6m (is adjusted according to the change of coal thickness on site, and cannot be left with top and bottom coal at will), and each of machine head and tail is about 30 frames with smooth transition with roadway roof. According to the roof condition on site, when the roof is broken and leaks gangue, the mining height can be adjusted to about 5.2m to prevent insufficient initial support of support. The cycle progress is 0.865m.

[0047] Mining technology: the machine head section (end frame and transition frame) of working face:

[0048] 1Collecting support side plate

[0049] When the machine group cuts coal, the support worker is responsible for collecting the side plate of the support in front of the upper roller (front roller) of the machine group, and the front roller is 1-2 frames, and one frame is collected each time. When collecting the side plate, the operator collects in sequence in the direction of the machine group. When collecting the side plate of the transition frame, if the support telescopic beam has not been extended, the secondary side plate (small side plate) should be collected first, and then the primary side plate (large side plate) is collected; if the support telescopic beam has been extended, the telescopic beam should be collected first, then the secondary side plate (small side plate) is collected, and finally the primary side plate (large side plate) is collected. When collecting the side plate of the end frame, the small side plate is collected in sequence. When collecting the side plate in this section, the angle of collecting the side plate should be controlled according to the coal body condition, and it must be ensured that the upper roller of the machine group can pass through smoothly, the side plate is not cut, and the loose coal side is protected as much as possible, the side plate is collected and protected, and large spalling is prevented.

[0050] When collecting the side plate, the operator must stand in the frame and operate in the pedestrian passage, and it is strictly forbidden to collect the side plate and telescopic beam in group, and it is ensured that no other personnel are in the three frames of the operation support and the adjacent two frames on both sides and in front of the frame before the operation (the frame interval refers to the middle of the adjacent two support columns).

[0051] 2Cut coal

[0052] This working face uses JOY7LS6C electric traction shearer, and uses two-way cutting method, that is, two cycles for one round trip of shearer.

[0053] Feeding method: end oblique cutting triangular coal feeding is adopted, and the total length of machine feeding is controlled at about 50m.

[0054] The machine set in this section of coal cutting is part of the end oblique cutting feeding, and the feeding method is:

[0055] A. After the machine set cuts through the machine head coal wall, adjust the upper and lower rollers, lower the left roller to cut the bottom coal, raise the right roller, and the shearer reverses along the curved section of the chute to cut into the coal wall.

[0056] B. After the machine body of the shearer enters the straight section and the cutting depth of the two rollers reaches 0.865m, stop the machine.

[0057] C. After the support is pulled through and sequentially moved to the top of the machine head, adjust the left and right roller positions to cut coal towards the machine head.

[0058] D. After the shearer cuts through the machine head coal wall again, adjust the left and right roller positions again to cut coal towards the machine tail, start the next cycle of coal cutting, and pull the support after cutting the coal.

[0059] The machine driver needs to control the cutting speed and quality to ensure smooth transition of the roof and floor without large steps, and to ensure that there is no one in front of the support and between the supports within 5m range of the machine body and rollers. During the cutting process, in addition to the machine driver and support workers, other personnel must be evacuated to a safe place 5m away from the cutting and support operation.

[0060] 3. Install the support plate

[0061] After the upper roller (front roller) of the unit passes, because there is a push block in front of this section of the support, and the preceding frame has already been pulled, the support cannot be pulled any further. To prevent roof collapse and side fall, the support workers should promptly install the side protection plates. When installing side protection plates, only one frame can be operated at a time; it is strictly forbidden to install side protection plates in groups. When installing side protection plates for transition frames, the small side protection plates should be folded up first, the large side protection plates should be installed to protect the coal side, and then the small side protection plates should be installed. It is forbidden to install the large and small side protection plates simultaneously. When installing side protection plates for end frames, the small side protection plates should be installed sequentially. After the upper drum (front drum) of the unit passes through, both the large and small side guards must be deployed without affecting the passage of the lower drum (rear drum). If the lower drum (rear drum) is affected, only the large side guards can be deployed, and the small side guards can be folded up. If the mining height is too low and neither of the two levels of side guards can be deployed, or if the distance between the beam ends still exceeds the specified limit after deploying the large and small side guards, the telescopic beam must be extended in time to protect the roof in front of the support. After the upper drum of the unit passes through, if the coal side and roof are intact and there is little risk of side collapse or roof fall, the side guards and telescopic beams can be temporarily suspended until the lower drum (rear drum) of the unit passes through, at which point the side guards can be deployed.

[0062] After the rear drum of the generator unit passes, if the side guard plates have not been installed or are incomplete, the support workers must promptly install them, installing the large and small side guard plates in sequence. If the beam end distance still exceeds the specified limit after the side guard plates are installed, the telescopic beam must be extended. The installation of side guard plates after the rear drum of the generator unit has passed must lag behind the bottom drum (rear drum) by no more than five frames; otherwise, coal cutting is prohibited. When installing side guard plates, only one frame can be operated at a time; it is strictly forbidden to install side guard plates in groups, and it is strictly forbidden to install the large and small side guard plates simultaneously. Both large and small side guard plates must be installed sequentially and completely, tightly against the coal face, for effective side protection.

[0063] Whether installing the side guard plates following the upper (front) or lower (rear) drum of the unit, it is strictly forbidden to install them in groups. Operators must operate from inside the frame and ensure that there are no other personnel between the three frames (the one to be operated, the two adjacent frames on both sides, and in front of the frame) before proceeding with the operation. When operating the frame, all personnel except the frame operator must evacuate to a safe location at least 5 meters away from the frame to be operated.

[0064] 4 move

[0065] After the oblique cutting at the end of the unit is completed and the frame is pulled over, the transfer conveyor and chute head are pushed forward. During the pushing process, the operators must coordinate and push out the transfer conveyor, chute head, and chute in sequence. The pushing of the chute adopts a bidirectional group pushing system with an electro-hydraulic control system, and each group is set up with 10 frames.

[0066] When moving the scraper conveyor at the working face, it must be done at a distance of more than 15m from the rear drum of the coal mining machine. Operators can only operate from the pedestrian walkway inside the frame after confirming that there is no one in front of or between the frames within 10 frames before and after the section to be moved.

[0067] 5-Pull Frame

[0068] After the pushing process is completed, start pulling the supports from the 1# frame (when the local slice is large and there is a risk of roof falling, the supports in that section can also be pulled first). Pulling the supports uses two-way adjacent support shifting and manual shifting, one support is shifted at a time, and group automatic pulling is strictly prohibited. Two-way adjacent support operation uses an electro-hydraulic control system for adjacent support operation, and manual shifting uses an inter-support electromagnetic valve group for this support operation. When pulling the supports, the operator must stand on the inside of the support column, and only when there are no other personnel in the inter-3 supports and in front of the support to be operated can the operation be performed.

[0069] 6 Punch the support plate

[0070] After the support is pulled, the support plate is punched in time, one support is punched at a time, and group punching of the support plate is strictly prohibited. When punching the support plate of the transition support, the small support plate should be folded first, the large support plate is punched, the coal slice is protected, and then the small support plate is punched. When punching the support plate of the end support, punch the support plate in order.

[0071] 7 Punch the support plate

[0072] The machine head should be cut according to the distance between the front row of supports and the coal slice. When the distance between the end support side plate and the coal column is less than 1200mm, only one cutting column can be cut for each row, and the row distance is not greater than 1m.

[0073] The cutting column is arranged at the end of the end support top beam towards the first row of wooden sheds or steel belts under the old pond, and two dense columns not less than 75° are punched, the dense columns are punched firmly and securely, the cutting column distance is not greater than 400mm, and the last second row of dense columns has a column distance not greater than 800mm. Before pulling the end support / end tail support, the cutting column is recovered first. When recovering the cutting column, recover it from the coal column side to the end support side, and then punch the last third row of wooden sheds or steel belts under the original, with a column distance not greater than 800mm. Fill in the dense columns under the original second row of steel belts, with a column distance not greater than 400mm, and punch two dense columns not less than 75° under the dense columns. Finally, the two dense columns are recovered, and the excess single column is transported out and stacked to prevent blocking the operator's retreat route.

[0074] The cutting column must be strong and effective in stopping coal. After the machine head cutting column is punched, a warning sign "No entry" must be hung between the machine head support and the coal slice to prevent any personnel from entering the machine tail old pond before the column is recovered.

[0075] 8 Clear coal

[0076] During the coal cleaning operation, at least two persons shall work together, one for cleaning coal and the other for observing the mountain, confirming that the roof and coal bank have been supported in place, the bank protection plate is effective, and then the coal can be cleaned. During the coal cleaning, the distance between the coal cleaning personnel and the supports for removing the support and collecting the bank protection plate shall be greater than 5 supports, the distance from the support for operating the push-slip operation shall be greater than 10 supports, the distance from the coal mining machine shall be greater than 50 m, the coal cleaning personnel must face the tail of the scraper conveyor and pay attention to the slipper, roof and coal bank to prevent accidents.

[0077] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining a coal face machine head transition coal seam floor, characterized by: The method comprises the following steps, S100: dividing the machine head section of the coal mining face into a flat section and a transition section, wherein the flat section is a section of the working face connecting the machine head crossheading and the transition section, and the transition section is a section of the working face along the coal seam floor; S200: performing flat section slope simulation, wherein the flat section is a slope surface with a slope, and the length and slope of the flat section are simulated; The length of the flat section is equal to the length of the machine unit, and the maximum slope of the flat section is not more than ±3 degrees; In the first simulation, the slope is ±3 degrees, and when the simulation result does not match the actual coal seam detection information in S400, the slope is adjusted to be less than ±3 degrees, and the minimum angle of adjustment is 0.1 degrees; S300: performing transition section slope simulation, wherein the transition section is connected to the flat section and the coal seam floor, and the slope of the transition section is changed from the slope of the flat section to -15 degrees, and then from -15 degrees to the slope of the coal seam floor, and the transition section comprises an upper vertical curve and a lower vertical curve; The transition section is an arc-shaped section, and the vertical curve radius corresponding to the arc shape is wherein R: vertical curve radius; L: length of the chute of the transition section; a: maximum slope angle in the vertical direction of the chute; S400: comparing the simulation results of the machine head section, the flat section and the transition section with the actual coal seam detection information, and if the simulation results match the actual coal seam detection information, the next step is performed, and if the simulation results do not match the actual coal seam detection information, S200-S300 are repeated to perform simulation; S500: performing coal mining according to the simulation results of the flat section and the transition section obtained in S200-S300.

2. The method for determining the coal face machine head transition coal seam floor according to claim 1, characterized in that: In S300, if the first simulation result does not match the actual coal seam detection information in S400, the value of the vertical curve radius R is increased, and the transition section slope is simulated again.

3. The method for determining the coal face machine head transition coal seam floor according to claim 2, characterized in that: The value of the vertical curve radius R is increased by less than or equal to 0.5 m each time.

Images