Numeric simulation of non-steady flow of liquid in dry pipe fire protection systems of tree type topology

The mathematical model of the dry pipe fire protection system having a tree type configuration is presented. It provides the quantitative description of the non-steady processes in it after sprinklers are opened: the gas discharge to ambience, filling up piping with liquid and the liquid discharge through sprinklers. The algorithm is developed for the dynamic formulation of system of equations at various stages of filling up piping with liquid. The effective procedure for the numerical solution of system of equations is presented as well as description of its application for calculating non-steady characteristics of liquid motion in a piping system. Calculated results are compared against experimental data for the trip, the transit, and the operating pressure time proving adequate accuracy of the developed model.