配煤槽水分分布模型的有限元解法模拟仿真
本论文利用对流方程和对流扩散方程, 建立一文情况下的水分渗透模型, 并采用有限元方法进行求解. 另外, 建立了配合槽的加煤和切煤模型, 以模拟实际的加煤和切煤过程.
对于渗透模型, 本文主要将其有限元方法(FEM)与有限差分方法(FDM)进行比较. 首先, 选取相同的均匀节点( , ), 两种方法的结果基本相同. 为了更好地模拟边界处梯度较大的情况, 采用相同数量的Chebyshev-Gauss-Labatto (CGL)点, 结果出现差异性; 为了验证FEM-CGL结果的正确性, 在FDM中, 选取步长为CGL点的最小步长( , ), 结果与FEM-CGL效果相同. 为了得到更合理的节点分布, 在模拟过程中, 结合自适应有限元的思想, 根据当前的含水率数据, 对节点进行重新分布.
最后, 利用所建立的模型, 模拟了实际过程.5423
关键词：水分分布模型 渗透 对流扩散方程 有限差分解法 重构
Finite element solution of water distribution model of coal blending trough
Abstract:
The hard coke quality affects the pudding index number to some extent, but the rationality of coal blending structure have an influence on hard coke quality about 30%.In the process of actual coal blending, the blending trough water set point lag behind nearly 24 hours, which affect the coal blending cut-out accuracy rate. Therefore, in order to guide the blending time and improve the accuracy of coal blending, it is necessary to study the water distribution and forecast the moisture content of coal in blending trough.
Using the convection equation and the convection-diffusion equation, this paper build water osmosis model in one-dimensional condition and adopt finite element method to solve the problem. In addition, in order to simulate the actual add or cut coal process. this paper also build the model of add or cut coal in blending trough.
With regard to osmosis model, the finite element method (FEM) and the finite difference method (FDM) were compared in this paper. First, select the same uniform dot( , ),the results of the two methods are basically the same. In order to simulate the condition of boundary which the gradient is large, we use the same number dot of Chebyshev-Gauss-Labatto (CGL). The result appears otherness. In order to verify the correctness of the result of FEM-CGL, we select the step size as the minimum step size of CGL point ( , )in FDM. The result is the same as the FEM-CGL effect. In order to get more reasonable panel point distribution, based on the current data of water content, we combine adaptive finite element method in the simulation process. As a consequence panel point distribution is changed.
Finally, we simulate the actual process by using the model.
Keywords: water distribution model, osmosis, convection-diffusion equation, FEM, reconstruct
目录
摘要 i
Abstract: i
1 绪论 1
1.1背景 1
1.2问题描述 1
1.3对流扩散方程的介绍 2
2 渗透模型的建立及求解 3
2.1渗透模型的建立及求解 3
2.1.1假设 3
2.1.2问题分析和模型建立 3
2.1.3 数值求解 5
2.1.4含水率的修正 9
2.2配煤槽中煤的增减模型 9
2.2.1切煤过程 10
2.2.2加煤过程 10
3 模拟仿真 12