Experimental and numerical investigation of odorant dispersion in natural-gas pipelines

One of the important factors in natural-gas pipeline networks is the optimal concentration of odorant injection. The purpose of this study is to investigate the behavior of odorant dispersion along the natural gas pipelines. A numerical modeling analysis has been conducted on odorant injection at the City Gate Station (CGS) of Shahrekord distribution network in Iran and validated with experimental data of a real gas pipeline at pressure and temperature of 1586 to 1723 kPa and 0-\(30 {}^{\circ}{\rm C}\), respectively. Navier-Stokes, concentration equations and k-\(\varepsilon\) turbulence model have been used for numerical modeling of the turbulent and incompressible fluid flow. The results showed that the low pressure or high temperature of the gas as well as the increase in the pipe length decrease the odorant concentration at the gas pipeline. In addition, odorant concentration decreases with high gas velocity and low initial concentration of odorant injection. Finally, by curve fitting through the obtained result, a correlation, with an average error of 3%, was proposed to calculate the final odorant concentration in natural-gas pipelines. This correlation is based on the temperature, pressure and velocity of natural gas, initial concentration and duration of odorant injection, length and diameter of the pipe as input parameters.