Stability Analysis And Simulation Of Mine Ventilation System

The mine ventilation system is an important part of the mine production system and the analysis of its stability is essential to the mine daily ventilation management. With the progress of mining work, the mine ventilation system is actually a dynamic and complex system, which affected by various factors. Therefore,the wind network structure is changing. In order to guarantee the safety of mine production,it is important to simulated the wind flow under the mine and the working status of the ventilator before the wind network structure changes. This paper conducts an in-depth study on the stability of the mine ventilation system and its simulated model by using the research methods of theoretical study, field measurement and numerical simulation.(1) The theoretical research and the numerical simulation are adopted to analyze the wind flow stability of the mine diagonal wind network. Based on that, the influence rules of the wind resistance changes on the wind volume are obtained. The curve showing the relationship between the wind amount and wind resistance changes is drawn. The subsection mathematical model is employed to describe the variation characteristics of the curve. The curve is divided into the wind resistance adjustment sensitive area, blunt area and influence-free area. If the wind resistance adjustment is within the sensitive area, the wind amount changes are significant. Once the wind resistance adjustment enters the blunt area and the influence-free area, the wind amount changes become insignificant, which is hard to achieve the purpose of wind adjustment. This is the major reason for the difficulty of wind adjustment within the mine.(2) Through analyzing the operation of the mine ventilator, the potential positions of the operating points in the coordinate and the instable operating conditions of the ventilator during the operation can be obtained. A method based on the least absolutely deviation to solve the characteristic curve of the ventilator in the mine is put forward. A curve fitting is conducted by the measured data of the ventilator. Compared with the traditional algorithm, the curvilinear equation based on the least absolutely deviation shows multiple zero deviation points. Its total deviation, average deviation and total deviation rate are smaller than those based on the least square method. Besides, the curve is less affected by the abnormal points. The fitting precision is relatively high and closer to the actual situation of the mine.(3) The equivalent wind network characteristic curvilinear coordinate equation is deduced. Based on that, the stability of the ventilation system with multiple ventilating shafts is analyzed. Acoording to the minimum power consumption theory, the optimal wind separation plan for the ventilation system with multiple ventilating shafts is the natural wind separation, which means the wind pressure of all branches of the ventilators are the same. In the wind network structure with multiple ventilating shafts, the wind output of various ventilating shafts is made to stay close to the wind amount of the natural wind separation through the wind resistance adjustment. This can effectively reduce the energy consumptionof mine ventilation.(4) The ventilation parameters of Zhilanchong Coal Mine under the current ventilation status are comprehensively measured so as to learn the ventilation status of the coal mine. The ventilation parameters including the frictional resistance coefficient and wind resistance value of the major ventilation courses, the resistance distribution of mine courses, the performance curve of ventilators, the natural wind pressure and the ventilation difficulty level of the mine are obtained. The test shows that the relative error is smaller than 5%, which meets the engineering requirements. Thus the data obtained are reliable and authentic.(5) The Ventsim 3D dynamic simulated system model is established to simulate the ventilation status. The simulation results are reliable and authentic. The simulated system can provide necessary technical support and decision-making references for the wind amount prediction and the optimization and transformation of the wind amount measurement after the in-depth development of the mine courses.