Study On Leakage Diffusion Detection Of Natural Gas High Pressure Pipeline And Its Application

With the rapid economic and social development of our country,and people’s demand for living environment is getting higher and higher,the demand for natural gas is also increasing.Pipeline transportation is the main transportation method of natural gas,but it will cause leakage due to third-party damage,pipeline corrosion,and pipeline quality.If it is not dealt with in a timely manner,it will result in the loss of resources and environmental pollution,and it will cause fire and explosion accidents,pose a great threat to people’s lives and property,cause major economic losses,and cause adverse social impact.Therefore,it is of great significance to carry out research on the detection of leakage and diffusion of high-pressure natural gas pipelines.In this thesis,tunable semiconductor laser absorption spectroscopy(TDLAS)was used to analyze and detect the natural gas leakage,and Fluent numerical simulation software was used to analyze and study the natural gas leakage diffusion rule.The main research contents of this thesis are as follows:1.Based on the optical basic theory,the measurement principle of TDLAS technology is elaborated in detail.The key research and decision is to select the absorption line of methane gas at 1653 nm as the absorption line for natural gas leak detection.Wavelength modulation technology and harmonic detection technology.2.Based on the knowledge of fluid mechanics,the basic control equations of natural gas leakage and diffusion are established.Fluent software is used to simulate the leakage and diffusion of natural gas under different conditions,and the law of natural gas leakage and diffusion is qualitatively analyzed.3.Performance testing of the TDLAS system,including the overall design and construction of the TDLAS system,and the use of the second harmonic signal strength to calculate the concentration of the leaked gas,the performance of the system from the three detection limits,repeatability and stability,response time According to the data obtained from the experiments,the TDLAS system meets the detection requirements for high accuracy and high sensitivity of trace gas leakage.This thesis mainly studies the leakage diffusion detection of natural gas highpressure pipelines,theoretical analysis,numerical simulation and laboratory tests are performed edge-by-side.TDLAS technology is mainly used to detect natural gas leaks.Compared with other detection technologies,TDLAS technology has high sensitivity and high The advantages of speed,high selectivity and non-contact provide a new method for natural gas leak detection,which has important practical significance.