Leak-proofing gas networks
Conventional methods for locating a gas leakage measure the gas concentration at a single point in space. This point measurement is time consuming and often brings difficulties in the interpretation of the readings, especially in variable wind conditions. Modern methods of visualisation include both passive (infra-red) and active (laser based) technologies, and are believed to speed up the process and lead to greater accuracy. VOGUE is an EU funded research project with primary aim to develop an accurate, reliable, and cost-efficient remote gas detection system. VOGUE was targeted to provide improved understanding of gas leak behaviour through passive infrared (IR) imaging of leaks, supported by the development of numerical models. In this direction a laser pointer and laser scanner system for remote gas detection were developed. The laser pointer is able to identify most leaks identified by conventional instruments under real world conditions. This has encouraged further development and use by gas engineers in the gas industry. Spectroscopic instrumentation, able to collect surface reflectivities, under different environmental conditions and a range of inclinations to the surfaces at the specific wavelength of the laser, further improves performance. More work is needed to clarify the relationship between the laser pointer measurements of gas concentration in ppm per metre in comparison to conventional concentration measurements of parts per million (ppm). In addition although conversion of the laser pointer unit into a scanner has been demonstrated in the laboratory, there is scope for further improvements. The VOGUE results provide new knowledge and instrumentation to aid the process of locating gas leaks from both high and low pressure gas mains. The benefits of the project may involve gas customers and personnel working within the industry as well as others affected by explosion hazards. The results obtained can be used for further improvements in remote gas detection techniques or instruments and the interpretation of the subsequent measurements.
