Development of Searching Strategy for Micro-Leakage in Natural Gas Stations Based on TDLAS Methane Detectors with PTZ Controller

Abstracts Detecting and locating micro-leakages pose significant safety challenges in the gas and petroleum industries. Typically, a single Tunable Diode Laser Absorption Spectroscopy (TDLAS) methane detector equipped with a PTZ controller can effectively mitigate the risks associated with potential leaks at natural gas stations. However, the lack of a dedicated search and localization function often results in operators spending considerable time pinpointing the source of a gas leak. To address this issue, a series of experiments and simulations were conducted to investigate integral concentration and evaluate its characteristics and influences. This led to the development of three search algorithms, which were assessed in a virtual environment: Global Searching Based on Steady Concentration (GSSC), Global Searching Based on Real-Time Concentration (GSRC), Spherical Search Based on Real-Time Concentration (SSRC). These algorithms were tested under field conditions, focusing on accuracy and response time across various scenarios. The results indicate that integral concentration, affected by factors such as optical path and concentration distribution, exhibits distinct characteristics. Notably, the highest values for both integral and gas concentrations consistently occur at the leak source. In the simulated leak scenarios, all three proposed algorithms successfully identified the leak locations. Among them, the SSRC algorithm demonstrated superior efficiency and accuracy by accounting for real-time concentration dynamics and the evolution of gas cloud diffusion. In field tests conducted at natural gas stations, the SSRC strategy effectively located leak sources with rates exceeding 300 ml/min and integral concentrations above 3000 ppm·m, achieving this within a 15-minute time frame.