Problems with the original model The four 2K60-4No28 main ventilators used in the Yanzishan Mine were products of a factory in China before 1984 and were put into use in 1990. Through analysis and research, it is found that this type of wind turbine has serious unsafe hidden dangers in design and manufacturing process. In design, the number of moving blades and the number of guiding vanes are not considered to be prime numbers. Therefore, the outlet airflow wave of the middle guide vane easily causes the second-stage bucket to resonate; secondly, the guide vane is adjusted by the wire rope winding and the synchronous rotation. Since the guide vane is adjusted and locked by the wire rope, the elastic/zero fixed In the operation of the fan, the deflection and even displacement of the vane are prone to occur and pneumatic interference occurs. The long-term use is easy to cause fatigue damage of the blade. In the manufacturing process, the petiole processing has almost no transitional fillet, which causes large stress concentration, which reduces the strength, and the spot blade is fixed by spot welding before the blade is riveted, so that the weld microcracks are generated at this place and the strength of the blade root is reduced. . On the other hand, the efficiency of this type of fan is low, and the high-pressure static pressure design is 39,204,900 Pa. This pressure range is only suitable for a few mines with high pipe network resistance in the later stage of mining. For the mine in the early stage of the Yanzishan mine, the pipe The net resistance is only 2500Pa, and the static pressure efficiency of the fan operation is only 60%, which is very uneconomical. At the same time, with the development of mine production, the required air volume is constantly increasing, so it is necessary to adjust the angle of the blade. However, according to the original Ministry of Coal documents, the operating angle of the series of fans must not exceed 35b, which limits the increase of air supply to the wind turbine, which restricts the development of the mine to a certain extent. Therefore, from the perspective of safety and economic benefits as well as the needs of production development, wind turbine reform is imperative.
The expected goal of technical transformation is to fully consider the safe operation and energy-saving factors of the wind turbine, and take into account the needs of the medium and long-term development of the mine. The expected objectives of the technical transformation are: (1) Eliminate the unsafeness in the original design and processing of the wind turbine. Hidden dangers to avoid resonance. (2) Increase the static pressure efficiency of the fan to over 70%. (3) Reduce power consumption, achieve energy-saving purposes, and recover and transform investment within two years. (4) According to the actual production of the mine, determine the operating parameters of the fan: the air volume is 8000-12000m3/min, the high efficiency point is 9000m3/min; the negative pressure is 11962194kPa, and the high efficiency point is 2157Pa. (5) The return air is reversed return air, and the return air rate is over 40%.
The specific methods of transformation are: (1) redesigning and processing the buckets and guide vanes. According to the principle that the number of moving and stationary blades should be prime numbers, and considering the interference of wind flow between the moving blades and the guide vanes, it is determined that the number of two-stage moving blades still remains the original 14 pieces, and the middle guide vanes are changed from the original 14 pieces. 19 pieces, the rear guide vane changed from the original 7 pieces to 11 pieces; the dynamic and static blade shape adopts the blade grid method widely used in aeroengine to design the blade shape, and at the same time changes the processing technology to make the surface streamlined, and Increase the shaft diameter of the petiole and increase the transition radius of the root to increase its strength. The way in which the guide vanes are adjusted by the wire rope is changed from the adjustable type to the fixed type. Weld the vane to the hub. According to the operating parameters and resistance curve of the mine, it is determined as 25b. The investment in the renovation of the two wind turbines is 400,000 yuan, and the investment recovery period is about 2117 years. From the main performance parameters of the fan before and after the technical transformation, the wind volume and wind pressure of the fan can meet the needs of the mine after the transformation, and the power saving effect is remarkable. Especially from the operation status after more than one year after the transformation, the operation is stable and the transformation is achieved. The expected goals have achieved good economic returns.
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