Mechanical model of domestic gas explosion load

Abstract

Abstract：With the increase of domestic gas consumption in cities and towns in China, gas explosion accidents happened rather frequently, and many structures were damaged greatly. Rational physical design could protect structures from being destroyed, but the character of explosion load must be learned firstly by establishing a correct mechanical model to simulate vented gas explosions. The explosion process has been studied for many years towards the safety of chemical industry equipments. The key problem of these studies was the equations usually involved some adjustable parameters that must be evaluated by experimental data, and the procedure of calculation was extremely complicated, so the reliability of these studies was seriously limited. Based on these studies, a simple mathematical model was established in this paper by using energy conservation, mass conservation, gas state equation, adiabatic compression equation and gas venting equation. Explosion load must be estimated by considering the room layout; the rate of pressure rise was then corrected by using a turbulence factor, so the pressure-time curve could be obtained. By using this method, complicated calculation was avoided, while experimental and calculated results fitted fairly well. Some pressure-time curves in a typical rectangular room were calculated to investigate the influences of different ignition locations, gas thickness, concentration, room size and venting area on the explosion pressure. The results indicated that: it was the most dangerous condition when being ignited in the geometry centre of the room; the greater the burning velocity, the worse the venting effect; the larger the venting pressure, the higher the peak pressure; the larger the venting area, the lower the peak pressure.

Dynamic Tests for Energy Absorption by Selected Auxetic Fabrics

“…The maximum bending moment in the support crosssection of the witness-plate is: Compressed gas was used to form a pressure impulse. The pressure vessel (2) was filled with argon taken from the bottle (3) through the pressure reducer (4) and proportional filling valve (5). The test manometer (6) was used to control the pressure in the vessel.…”

“…The discharged gases carry away large amounts of energy after venting. The pressure rise in the room is determined by the difference between the released energy during the combustion and the discharged energy [5].…”

“…A propane-air mixture gas explosion in a vented room can be considered under the following assumptions [5]: (1) heat transfer between the gas and the obstacles is ignored; (2) the pressure remains uniform in the whole room during the explosion; (3) the flame surface is spherical.…”

The consideration of the turbulence influence on the gas explosion expansion in non-closed areas

“…Hitherto in the calculation of pressure during the gas explosion in non-closed vessels it is widely used [1][2][3][4][5] the way of its modeling (in terms of pressure "quasiconstancy") by means of using the mass balance equation in form:…”

“…In all known publications the modification is introduced to the burning rate u. The concept of "turbulent burning rate" is being also introduced [4][5][6][7][8].…”