含有单向回路的风网平衡图绘制方法

在火风压作用下发生风流逆转和采用多级机站通风的矿井往往存在单向回路。通风网络中存在单向回路时，将无法绘制其所对应的平衡图。采用通风网络拓扑关系等效变换的方法，删除造成单向回路的风机分支，并构造新的风机分支．其末节点是新网络的汇点，原风机分支末节点是新网络的源点，变换后的网络与原网络在分支数上相同，说明平衡图矩形块的个数不变。除造成单向回路的风机分支外，变换后的网络与原网络拓扑关系相同。将含有单向回路的通风网络变换成无单向回路的通风网络，从而实现了含有单向回路的风网平衡图的绘制。

Plotting method of ventilation network equilibrium graph with unidirectional circuit

Unidirectional circuits always exist in mines which adopt multistage fan station ventilation type and airflow reversion appears under the function of fire-heating air pressure. If unidirectional circuits exist in a network, the corresponding ventilation network equilibrium graph can not be plotted. In the paper, the equivalent transformation method is applied to the topology relationship of ventilation network. The method is to delete the branch with fan which result in unidirectional circuits, then construct new branch with fan whose end node is the sink of new network, and the end node of former branch with fan is the source of net network. The transformed network has the same branch number with former network, and this shows that the number of rectangle blocks of equilibrium graph is invariable. The topology relationship between transformed network and former network is uniform except the branches with fan which result in unidirectional branches. A ventilation network with unidirectional circuits will be switched to a ventilation network without unidirectional circuits, and thus the equilibrium graph of ventilation network with unidirectional circuits can be plotted.