Coal Technology Electromechanical and Informatization Optimized Design of Compressed Air Supply System for Mine Dust Chambers. The gas mode is transported through the seamless steel pipe to the functional modules of the refuge chamber. In order to verify the reliability of the system, taking the 60-person refuge chamber as an example, the number of cylinders required for the compressed air supply system and the supply pipeline were designed and calculated, and the pressure test and sub-system function test of the gas supply pipeline were carried out. The test results show that the gas supply pipeline has no leakage under the pressure of 1.8MPa and continuous pressure test of 30mm; the compressed air output pressure is adjusted to 12MPa, and the compressed air supply system fully meets the compressed air use requirements of each functional module of the evacuation chamber.
The TD774A mine refuge chamber is mainly used for emergency hedging when miners are trapped in gas accidents such as gas (dust dust) explosion, roof collapse, fire barrier, and impact pressure. It can resist explosion shocks, protect high-temperature smoke, and isolate toxic and harmful gases; it can provide oxygen, food, drinking water, remove toxic and harmful gases, cool down and dehumidify, provide basic living conditions for hedgers, and provide disasters for disasters. After the rescue, create conditions and win time.
The compressed air supply system is an important part of the refuge chamber. It can supply the air curtain spray system when the mine pressure is damaged, and provide the power source for the passive ice storage air conditioning system to ensure the function modules of the refuge chamber. Normal work. In this paper, the compressed air supply system for some refuge chambers in China is studied. The optimization design analysis of the compressed air supply system for mine refuge chambers shows that the compressed air bottles required for each functional module in the mine refuge chamber are basically distributed. Both are low-pressure confluence gas supply methods. The compressed air is decompressed by the air pressure reducer and then converged, and is sent to the functional modules of the refuge chamber through the stainless steel gas supply pipeline. However, the current application of the refuge chamber compressed air supply system has a large number of pressure reducers used in the low-pressure confluence mode, and the cost is high, which reduces the market competitiveness of the product; the compressed air bottle dispersion arrangement reduces the space utilization of the diverticulum, and avoids danger. The operation of the personnel entering the diverticulum is cumbersome; if there is an accidental leakage of the compressed air bottle, all the cylinders of the air bottle group cannot be used continuously, resulting in waste of indoor resources. Therefore, this paper optimizes the design of the current refuge chamber compressed air supply system.
1 The refuge chamber compressed air supply system principle design The new refuge chamber compressed air supply system is shown in Fig. 2. The compressed air supply system uses the air high pressure confluence method to replace the existing low pressure confluence gas supply mode, and will take refuge. All the compressed air bottles in the chamber are arranged in a centralized manner, and the compressed air is condensed to the end of the gas station. After being depressurized by the pressure reducer, the two ends of the compressed air station are respectively transported to the air curtain spraying system and the ice storage air conditioning system, and the actual use process will be The outlet pressure of the pressure reducer is adjusted to 1.2 MPa. Since the working pressure of the air curtain spray system is about 0.4 MPa, a secondary pressure reducer needs to be added, and the ice storage air conditioning system can directly use the gas output of the gas station as a power source. .
2 Refuge chamber compressed air supply system design calculation 2.1 compressed air supply system cylinder volume calculation volume 80L cylinder storage compressed air, cylinder actual filling pressure is 12MPa, according to the law of gas energy conservation, the air volume of a single compressed air bottle : P2 - atmospheric pressure, MPa; V2 compressed air release, L. In summary, this paper designed a total of 35 bottles of compressed air for 15MPa, 80L cylinders, which can meet the supply of compressed air in the shelter.
2.2 Compressed air supply system main road design and calculation The compressed air supply system adopts seamless steel pipe instead of conventional stainless steel pipe as the gas supply pipeline. According to the knowledge of fluid mechanics, the diameter of the pipe in the gas pipeline and the flow rate, working pressure and pipeline The length is related to the pressure loss and other factors. The inner diameter of the pipe can be calculated according to the following formula: P1 - working pressure, Pa; Δp pressure loss, generally not exceeding; nominal length of L pipe, m; from the foregoing, compressed air supply system Working pressure corpse: 01MPa, the length of the pipeline between the compressed air station and the air curtain spraying system of the 60-person refuge chamber is L=8 m, and the total air consumption of the air curtain spraying system is Vi=2575L/min, which is 0.043m3/s. Calculate the available gas supply main pipe inner diameter 20mm. The length of the pipeline between the compressed air station and the ice storage air conditioning system of the 60-person refuge chamber is L2 = 12m, and the measured air consumption of the air-conditioning system air-purifying air-conditioning system V2 0004m3 /s. Calculate the available gas supply main pipe inner diameter '4mm. In the above calculation results, the diameters of the two gas supply pipes are quite different, because the air consumption of the ice storage air conditioning system is the rated value, according to the fluid Knowledge related to mechanics, if the gas source chooses a larger inner diameter of the pipeline, it will not add the compressed air consumption of the ice storage air conditioning system, and reduce the flow resistance of the compressed air, and it is easy to ensure the working pressure of the ice storage air conditioning system.
Therefore, the compressed air pipeline design uses k25 mmX2.5mm (outer diameter X wall thickness) seamless steel pipe, the inner diameter is 20mm, and its cross-sectional area is much larger than the cross-sectional area of 2 inner diameter pipes of 4mm, which fully meets 2 sets of ice storage air conditioners. System gas supply requirements.
According to the knowledge of material mechanics, the pipeline is subjected to uniform internal pressure, and the normal stress of the inner wall is calculated as: - internal stress of the pipeline, pressure of the pipe of MPa, MPa; outer diameter of the pipe, mm; inner diameter of the pipe, mm. 5mm seamless steel pipe withstand pressure of 12MPa According to formula (5), ff=4. Query relevant data shows that the yield limit crs seam steel pipe with seamless wall thickness less than 16mm can meet the pressure requirements of the refuge chamber compressed air supply system.
3Compressed air supply system function test According to the above technical design, the installation of the refuge chamber is carried out, and the system function test is carried out after the installation.
3.1 Gas supply line airtight test The air supply line is marked with a marker pen at each interface of the gas supply line to optimize the design of the compressed air supply system for the mine refuge chamber (116), and a compressed air bottle valve and a corresponding busbar angle seat are opened. Valve, close the air curtain sprinkler control ball valve and ice storage air conditioning system air purification cycle processor control valve, the pressure output of both pressure reducers are adjusted to 18MPa, hold pressure for 30min. Apply soap liquid to each pipe joint for seepage Leak check and record test data. It can be seen from the test data that there is a slight leakage in the pipeline connection of the inspection. The reason is that the joint thread is damaged during the installation process, resulting in seal failure, and the other pipeline joints have no leakage. The product qualification rate is 93.8%. The compressed air supply system is airtight.
3.2 Air curtain device function test Close the mine pressure air supply balloon valve, open the air curtain ball valve, release the residual gas in the pipeline; open a compressed air bottle valve and the corresponding busbar angle seat valve to adjust the pressure reducer output The pressure is opened and the protective airtight □, the air curtain is generated, the air flow can cover the entire protective airtight □, the protective airtight □ is closed, and the air curtain disappears. The test record is shown in Table 1. Table 1 Air curtain device test record Air curtain device number linkage test Recording the air curtain coverage inspection record/mm linkage normal As shown in Table 1, the air curtain and the protective airtight □ linkage are normal during the test, and the airflow from the air curtain tube can cover the entire door frame. The test proves that the compressed air supply system can be Meet the needs of air curtain installations.
3.3 Sprinkler function test Close the mine pressure air supply balloon valve, open the spray ball valve, release the residual gas in the pipeline, and then close the spray ball valve.
Open a compressed air bottle valve and the corresponding busbar angle seat valve, adjust the output pressure of the pressure reducer to 0.4MPa, record the value of the high pressure gauge of the pressure reducer at this moment; close the protective sealing □, open the spray ball valve, and time 2min, Then close the spray ball valve and record the value of the pressure reducer at this moment. The flow test record of the sprinkler is shown in Table 2. Table 2 The flow test record of the drenching device The number of the drenching device No. before the test of the gas cylinder after the test of the gas cylinder test The gas consumption and flow rate of the sprinkler are respectively according to formula (6) and formula (7) Calculation: q after Pm2 cylinder test pressure, MPa; cylinder volume, L; the values in Table 2 are substituted into equations (6) and (7), respectively, in the test using 1550/80L cylinders in accordance with GB5099 storage compression Air, available air spray volume 0 = 20801, Q2 = 232L; sprinkler flow q = 14L / min, q = 1160L / min. From the above calculation results, the spray device flow rate, > 500L / mm, test It is proved that the compressed air supply system can meet the needs of the shower device.
3.4 Function test of ice storage air conditioning system First connect the ice storage cabinet to the air conditioning system, fill the ice storage cabinet to the middle of the observation window, and connect the line for ice storage.
After the ice storage is completed, the air conditioning system is stopped, the air purification cycle processor is connected with the ice storage cabinet, a compressed air bottle valve is opened, the output pressure of the pressure reducer is adjusted to 1.2 MPa, and the air purification cycle processor control valve is slowly opened. Adjust the switching valve to the “continuous processing” position, and use the wind speed and air temperature meter to test the wind speed and air temperature under the air purifying loop processor. Select 5 test points, then take the average value. The test data record is shown in the table. 3. Table 3 Air outlet wind speed Wind temperature test recording time Continuous processing mode Rapid processing mode Wind speed Wind temperature Wind speed Wind temperature The air purification cycle processor switching valve is adjusted to the "rapid processing" position, using the same method to test the outlet speed and air temperature The test data record is shown in Table 3. As can be seen from Table 3, the average wind speed of the air purification cycle processor is >3.5 m/s, and the average wind speed is >11 m/s during rapid processing. The test proves that the compressed air supply system can meet the requirements. Ice air conditioning system use requirements.
