矿井风网与采空区流场边界耦合模型与求解技术

Boundary coupling model and solution technology of mine ventilation network and gob flow field

为揭示煤矿巷道和采空区中整体风流的流动机理,通过将采空区漏风边界的流量添加到矿井通风网络,建立矿井风网与采空区流场的边界耦合模型。基于矿井通风网络的节点压力解算法与采空区渗流场的有限元求解法,研究矿井风网与采空区流场边界耦合模型的迭代求解流程。分析基于线性渗流模型求解采空区非线性渗流模型的方法及控制方程组,用PARDISO作为耦合模型中大型稀疏线性方程组的求解器的软件开发接口。采用VC++与ObjectARX编写相应的模拟软件(简称i-MVS)模拟2个算例,验证模型的有效性与性能。研究结果表明:采空区流场的模拟需要矿井通风网络的解算结果为其提供压力边界条件,对新的矿井通风网络的解算又需要采空区流场的模拟结果来提供漏风边界上的流量,两者之间形成了相互依赖的耦合关系;耦合模型中的新风网是一个含有边界流量的不闭合网络,必须采用矿井通风网络的结点压力法进行解算;耦合模型实现了矿井通风网络与多个采空区流场的集成求解,其计算量是常规采空区流场模拟的若干倍,采用PARDISO求解器实现了对耦合模型的高效求解;相比于常用的模拟煤矿采空区流场的方法,耦合模型的准确度提高了12%。

To describe the mechanism of the airflows in the airways and gob areas of underground coal mine,the boundary coupling model of mine ventilation network and gob flow field was established by adding the flux of the air leaked into gob to mine ventilation network.Based on the node pressure method for mine ventilation network and the finite element method for gob seepage field,an iterative solution process for the boundary coupling model of mine ventilation network and gob flow field was studied.The method of solving the nonlinear seepage model of dob and the related equations were analyzed based on the linear seepage model.The programming interface of PARDISO was studied to solve the large sparse linear system in the coupling model.A computer program of i-MVS was developed to implement the coupling model in VC++and ObjectARX.Two illustrative examples were created to verify the validity and performance of the coupling model.The results show that the simulation of gob flow field needs the solution of mine ventilation network to provide pressure boundary conditions,and the solution of the new mine ventilation network needs the simulation results of gob flow field to provide the flow on the leakage boundary,which forms a mutually dependent coupling relationship.The new ventilation network in the coupling model is an unclosed network with boundary air flow of gob and can only be solved by the node pressure method of mine ventilation network.In the coupling model,the gob flow field is simulated with the ventilation network simultaneously resulting in its amount of calculation being several times of that of the common gob flow field simulation.The solver of PARDISO is efficient in solving the coupling model and the accuracy of coupling model is improved by 12%compared with that of the previous method.