Entrapped air may lead to high uncontrolled peak pressures with a potential risk of pipe rupture as well as considerably increases in energy losses. For this reason air valves are used to control the air flow in and out of the system (e.g. at high points). This paper describes an experimental programme on the dynamic behaviour of air valves performed in a large-scale pipeline apparatus. Dynamic flow tests were performed at large (full) scale, since previous quasi-steady flow tests at small scale did not lead to realistic results. Investigations in a large-scale pipeline apparatus lead to a better understanding of the physical processes associated with the dynamic performance of air valves. Float type air valves of nominal diameter of 50 and 100 mm were tested in geometrically similar 200 and 500 mm test sections, to allow for the assessment of dynamic scale effects and the development of dimensionless parameter groups and dynamic scale laws. The approach in the determination of the dynamic performance of air valves was to measure their response to flow acceleration/ decelerations, which are imposed upon the valve. In this way, the air valve behaviour following events like system start-up, pump trip and pipe rupture is simulated. Key results of the dynamic flow tests, including air release tests (valve slam) and column separation tests (effect of air valve on surge suppression), are presented and discussed.
Dynamic behaviour of air valves in a large-scale pipeline apparatus
Strojniski vestnik - Journal of Mechanical Engineering ; 58 , 4 ; 225-237
2012
13 Seiten, 9 Bilder, 1 Tabelle, 22 Quellen
Article (Journal)
English
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