Simulation Study On Leak And Diffusion Of Hazardous Gas Such As Combustible Gas In Plant Area

This thesis surveys the current situation of research on hazardous gas leak and diffusion, conclude the form and characteristic of hazardous gas leak and diffusion. Experiment in a scaled-model and numerical simulation were adopted so that to research rules and important affect factors of hazardous gas such as combustible gas leak and diffusion in plant area..Non-dimension analysis and similarity theory were used to discuss the simulation principle and physics sense for small-scale model simulating ture-condition on hazardous gas leak and diffusion. An experimental system was established, use liquid CO₂ as experiment medium to simulate hazardous heavy gas.With an eye to the characteristic of hazardous gas leak and diffusion, use the numerical model of hazardous gas leak and diffusion in air, to simulate the hazardous gas leak and diffusion, as the condition is similar to experimental, The numerical result calculated by the program are compared with the experiments, the agreement between the simulation and experiment is good. Base on it, to simulate the hazardous light gas (In the thesis is natural gas) leak and diffusion in plant area. The effect of wind speed, windward, sustaining time, location and orientation of leakage source on concentration field and fatalness region of natural gas leak and diffusion is studied.By analyzing the results of experiment and numerical simulation, it shows that effect ofwind speed and windward on concentration field on concentration field are notable, natural gas after leakage in leeward is diffuse fastest, in most instance, with the increase of wind speed, concentration value will fall evidently; because the dilute and transport effect of wind, with the increase of wind speed, fatalness region of natural gas leak and diffusion will minish evidently; with the distance between dimensional spot and location of leakage source is increase, change orientation of leakage source will have evident effect on concentration field and fatalness region of natural gas; when the wind speed and windward are steady , the concentration value of dimensional spot change along with time is inapparent, it may be considered steady.