CFD Simulation Of Diffusion Process About CNG Gas Storage Well Leakage Underground

With the development of economy, car ownership increases. At the same time, itbrings the problems such as air pollution, and energy shortage. Relevant nationalpolicies, energy saving and emission reduction needs, and good economical efficiencycreate a good environment for the natural gas vehicle industry development. To providepowerful guarantee for the growth of natural gas vehicle, a big increase in vehicle fuelgas filling network density is imperative.CNG (Compressed Natural Gas) gas storage well is a common form of CNG fillingstations gas storage, mostly buried in the place where people are crowded, thetransportation is convenient. Leakage of gas storage well can cause energy waste.Moreover, because of its gas storage of flammable and explosive and pressure is high,once the leak, easy to cause serious casualties and property losses, bring the bad socialinfluence. The attention of the public security and the high rate of hidden danger in thegas storage wells, force us to focus on gas storage well leakage diffusion problem.This topic introduces the structure and working mechanism of CNG gas storagewell, analyzes the diffusion process of CNG gas storage well underground leak. Then,sets up the control equations of gas diffusion and turbulence, porous medium models,and gives the two-dimensional mathematical model of CNG gas storage wellunderground leakage diffusion. Finally, computes with the CFD numerical simulationsoftware to get the rule of natural gas diffusion and pressure distribution.Through the analysis we can see that after the gas storage well leak, soil resistanceto high pressure natural gas to form high speed jet. Soil gas present in highconcentration state of aggregation, once spread out of the ground, decreases rapidly.Leak point pressure contour is very dense, and pressure attenuation is intense. Withinthe layers near the ground pressure contour is also very dense, and pressure attenuationis intense too. Once the gas comes into the atmosphere area, pressure quickly reduces toatmospheric pressure. In addition, the simulation got influence area and gas explosionarea in different time. The characteristics of gas explosion concentration area are: applyto close near the ground, influence range, long duration and serious hazard.This topic provides an analytical thinking for CNG gas storage well undergroundleakage diffusion research. Research results not only can be used as reference to guidethe CNG gas storage well the embedding location, but also can improve the gas storage well accident investigation and analysis, risk assessment and safety management.