| After finishing engineering construction of natural gas pipes, in order toprevent air and natural gas in the pipeline from mixing and make sure that themixing proportion of natural gas and air is not in the range of flammabilitylimit, replacement of the air in the pipeline is a key point for the operation ofthe pipeline. The paper studied on the Zibo-Laiwu line. According to theoperating scale, the following are studied including gas diffusion theory,diffusion coefficient, turbulent flow theory, instability and turn of laminarflow and so on. Connected with the replacement method, it studies the relationof diffusion and turn with gas mixing and the affect of pipe pig on gas pattern.The replacement of nitrogen has been studied deeply in the paper, includingpipeline drying,replacement gas selection and pipe pig selection, nitrogeninjection technology and replacement model. It is successfully applied in thepipeline of nature gas of Zibo-Laiwu line, including injection point, injectionflow, injection parameters, injection equipment and construction preparation. |
