Analysis On Interference Of Multiple Fans' Joint Operation

Mine ventilation is important for the safe production of coal mine. With the expansion of model of coal mine and range of exploitation, it is becoming more and more common that using multiple shafts to intake air and using multiple fans to discharge air. For coal mines with multiple fans, because of the difference of ventilation capacity and dynamic character of ventilation network, it will lead to the problem of interference of multiple fans'joint operation, and the air flow of mine is unstable, even some place is reversing. So it will affect the effects of fan's joint operation and decrease the safety and reliability of mine's ventilation system.The main methods of studying on fans'joint operation are graphic method and numerical analysis method. In the thesis, the adopted theories mainly are the balance law of air volume and the air pressure, the resistance law, network character and the method of least squares. The fan's characteristic curve's fitting adopts Origin which is based on the method of least squares, and it will obtain the precise curves as well as characteristic equation of fans' curves.After making summary and induction, it makes a detailed classification of fans' joint operation: The series operation of different types and same type of fans, series operation of fans and natural air pressure, parallel operation of different types and the same type of fans, diagonal and parallel operation of fans; the joint operation of main and auxiliary fans. Meanwhile, it makes correlative characteristic analysis and comparison of different types of joint operation.According to the different characteristics of ventilation network, this thesis makes comprehensive use of three fundamental laws and network' characteristic of mine ventilation system, and it analyses and studies the diagonal ventilation system on two wings, H ventilation system, multiple fans ventilation system and multiple fans ventilation system with separated air intake lines by turns, also it obtains the discriminant of interruption between fans. Meanwhile, it gives related prevention measure and the lectotye of fans. By computer simulation, it determines the actual effects of fans'joint operation.In the end, the thesis takes example of Huafeng coal mine to make discriminant of diagonal fans on two wings, analysis ventilation system of different periods, bring up the best program and get conclusion that the two fans have no interference. And it supplies reliable evidence for modification of mine's ventilation system. In the period of the sixth level's regular production, the program of build a new intake air shaft on -1100m level, build a new discharge air shaft on -500m level, and modify the pipe shaft to intake air shaft is the best program.