Study On Ventilation Simulation System Based On AutoCAD Map3D

In the ventilation management of coal mine, not only the current situation ofsystem ventilation is understood, but also the impact on the ventilation system forventilation system changes is predicted. To achieve the requirement, a perfectventilation simulation system is needed as an auxiliary tool. This paper introduces theventilation simulation system research and its related theory.Generally there are three development modes of ventilation simulation system:one is based on AutoCAD re-development. In this mode, Functions of the ventilationsimulation system is embedded in AutoCAD and the ventilation map is drawn byusing AutoCAD's own drawing function. The Second start from infrastructuredevelopment and independent of other graphics software. Its development isnecessary to realize functions of the ventilation simulation system, but also thedrawing function. The third is based on the GIS's re-development. The third mode isused in the development of ventilation simulation system, namely the use of GIS'sre-development. But the selection of GIS software is AutoCAD Map3D. AutoCADMap3D is a piece of GIS software and developed based on AutoCAD. It has all of thefunctions of AutoCAD and is fully compatible with AutoCAD. In fact,re-development of AutoCAD Map3D needs re-development interface of AutoCAD,that is, re-development of AutoCAD Map3D need to be familiar with AutoCAD'sre-development function.It is one of the key technologies of ventilation simulation system development,which finds spanning trees and minimum spanning trees of ventilation network.Commonly used algorithms of minimum spanning tree are Prim algorithm and Kruskalalgorithm. Kruskal algorithm is difficult to realize of the last two algorithms. Thispaper use Disjoint Sets realize Kruskal (Kruskal) algorithm. The algorithm reducedthe space complexity and time complexity. Disjoint Sets is used to represent a set ofdynamic sets. Its mathematical model isS={s₁, s₂,L,s_i,L,sn},s_i is a set ofelements.In mine ventilation simulation system, the mathematical treatment of naturalventilation has been a difficult problem of ventilation calculation. In this paper, byusing basic circuit matrix C and potential drop vector HNof network branches, thebasic circuit natural wind pressure calculation model is established and a theoremgiven: the product of ventilation network basic circuit matrix C and potential drop vector HNis natural wind pressure vector of the basic circuit.Commonly used algorithms of Ventilation network calculation areNewton-Raphson and Scott-Hinsley. Convergence radiuses of last two algorithms arevery small. Ventilation simulation solution often does not converge. In order to solvethis problem, this paper proposes using homotopy algorithm to solve the problem ofventilation network solution.The initial value of ventilation network solution is also a difficult problem ofventilation simulation software. This paper proposes the method of solving the initialair quantity by using independent path matrix, and solves the automaticallycalculation problem of the initial value of air quantity.In the ventilation network simulation, the main fan individual characteristiccurve is very important. In this paper the main fan characteristic curve fitting and itsalgorithm are also studied.The management of ventilation technology needs to know air energy of anyplace in the mine. In order to solve this problem, there are the following tools:(1)ventilation system air energy (pressure) slope map,(2) ventilation network relativepressure diagram,(3) ventilation network relative entropy static pressure diagram.These three tools are of common pitfalls: heavy workload of determination ofresistance, manual calculation and artificial drawing; inconvenient and intuitive foruse; underdetermination of air energy of any place and so on. In this paper, theconcept of ventilation system air-level map is produced, and we give a method forcalculating air-level and its computer realization method.Finally, taking Qianyingzi mine, Wanbei coal-electricity Group Company as anexample, the paper introduces the application of the ventilation simulation system.