Security Design And Software Development Of Flammable Gas Devices

Nowadays, the economical and efficient approach to prevent deflagration of flammable gas in closed vessels, which could destroy the vessel and cause serious life and property damages, is to install rupture disks. Therefore, the investigation into venting process of deflagration, which is of great importance for further study on design methods for safety venting, can be carried out through experimental study and numerical simulation. Limited by field, measurement techniques and outlay problem, it is impossible to get universal laws from experiment study. However, with the development of computer technology, numerical simulation has been proved to be more and more effective and accurate so that it could support practical engineering well.Based on Li Keshan's non-constraint model of gaseous vented deflagration, by refining location of ignition, flame area, burning velocity and constraint condition of vent, a math model of gaseous vented deflagration for flammable gases was advanced. Runge-Kutta algorithm is adopted in program to numerically calculate the process of vented gaseous deflagrations in the cylindrical vessels. Tested by experimental data from literatures, the computed system built in this paper is proved to be of good commonality, and the computational mistake is around 20%.User interface was designed and system of numerical simulation was established by language of MATLAB. In this system, once design parameters presented on interface are inputted, various kinds of numerical simulations of gaseous vented deflagrations with different initial conditions can be performed. Furthermore, variety of parameter sub module of flammable gases was provided to help users perform self-definition simulation. In addition, the impact force produced during the process of venting was also calculated.Results of the procedure indicated that in the process of gaseous vented deflagration, compared to closed end and vent ignited, the maximal pressure of vented deflagration is the highest, and left and right flame plane had different flame propagation velocity. The sort of flammable mediums had great influence on closed deflagration, but almost no impact on vented deflagration.At last, by analyzing vented deflagration time using the procedure advanced here, a formula for vented deflagration time is presented.