Performance Study of Piezo Electric Gas Feed Valve on Prototype of the SST-1 Gas Fueling System

摘要

Piezoelectric gas feed valve is normally used to introduce fuel gas in the vacuum vessel of tokamak device. The piezoelectric crystal of the valve is the element that controls the amount of gas. Typical response time of this valve is 0.002 s. Gas through put from this valve depends on various parameter such as time for which valve is open, voltage applied to the valve and pressure at the inlet of the valve. Characterization of piezo electric gas feed valve was carried out on the prototype of Steady state tokamak (SST-11) with respect to the above mentioned parameters. The prototype is l/8th the volume of SST-1 vacuum vessel. The experiment was performed to study the various aspects connected with the gas feed valve as well as the gas feed line for example, effect of line length, gas species on the response time, the difference in response time for the step down transient and the step up transient, the effect of pop up voltage on the piezo electric valve. This paper discusses some of the results of the experiment performed.