Sensltivity Analysis Of Mine Ventilation System And Its Application

A mine ventilation system is a dynamic, large scale, nonlinear system composed ofcomplex networks with multi-parameter input and output. There are many factors influencingit. Changes of every element will change input parameter. If input parameter was changed, theoutput parameter will also be changed.It is very important to analyze sensitivities of the system. When there are needs forpredicting the changing trend and changing rate of output parameters with changed roadwayinput parameters; or adjusting roadway input parameters to fit tested results at the field; orchanging airflow distribution, or adjusting operation conditions of the fan; or performing faultdiagnosis of the system, or assessing the quality of mine ventilation, the need for calculationof output parameter changing rate under various input conditions will be raised.This paper is based on the achievement of studies on air quantity sensitivity. Because thesensitivity analyzing was only used to analyze the relationship of air quantity and resistance,thus the usage of the theory to ventilation system analysis has been limited so far. This paperintroduces the concept, calculation method and relevant application of fan pressure sensitivity,node pressure sensitivity, sensitivity of"imposed pressure", and researches on the followingaspects have been launched.First, based on the mathematical model of loop analysis method of ventilation network,the analytic formula of air quantity sensitivity matrix S^Q_Ris derived. A mathematical modelof monitor allocation optimization is proposed by coupling ventilation sensitivities andminimum spanning tree theory. Key roadways in safety management of the mine can beidentified through proper application of matrix S^Q_R. A quantitative definition of ventilationadjustability of branches as well as the adjustability of ventilation system is proposed based on matrix S^Q_RSecond, based on the need of reducing the resistance of the ventilation system, thedefinition of fan pressure sensitivity and the matrix S^H f_R of that is proposed, the analyticformula of fan pressure sensitivity matrix S^H f_R is derived, and applied matrix S^H f_R inpredicting changing tend of fan pressure with changed roadway resistance or choose optimumbranch to reduce resistance.Third, from the requirement of pressure balance for fire extinguishing, the definition ofnode pressure sensitivity and the matrix S^Q_R of that is proposed, based on the mathematicalmodel of node analysis method of ventilation network, the analytic formula of node pressuresensitivity matrix S^Q_Ris derived. Applied matrix S^Q_R to predicting changing tend of nodepressure, chose the position of pressure balance facilities reasonably in pressure balancing fireprevention and extinguishment, and estimated variation of resistance.Forth, In order to study the effects of heat source in mine, air conditioning system, firewind pressure, auxiliary fan to ventilation system, the definition of"imposed pressure"andsensitivity of"imposed pressure"and the matrix S^Q_Hin of that is proposed, the analyticformula of matrix S^Q_Hinis derived. Applied matrix S^Q_Hinto predicting changing law ofairflow distribution with imposed wind pressure to one roadway, also studied the method ofchoose optimum branch to changing airflow distrubution and estimated variation of pressurewhile singular required air branch. The concept of fit degree of the branch and requirement ofair adjusting was proposed. The problem of choose optimum branchs set and calculate thevalue of adjusting pressure was solved by coupling the sensitivities and loop method or pathmethod. The calculating method of critical fire wind pressure and critical temperature to leadairflow reversal during mine fire is proposed.Fifth, based on MATLAB, C#, this paper developed integrated software with thefunction of mine ventilation network solution, sensitivity analysis, and requiredwind calculation, calculate air regulation etc.