Development of the mass flow quench detection system for the 100kWh SMES forced-flow model coil

High reliability of quench detection system is required for the coil protec tion of large scale superconducting power system of SMES. The mass flow que nch detection system of a forced-flow coil in SMES has been developed as th e second quench detection system, while an electrical bridge detection syst em should be the primary one. To study the characteristics of hydraulic phe nomena in cooling path during the coil quench, we optimized parameters of o rifice flow meter. Three kinds of orifices were designed and fabricated. Th ey were located at both inlets and outlets of cooling paths in the coil to measure the mass flow rates. The change of mass flow rate after quench were well observed. The response times after quench were measured. The relation ship was observed between the quench detection time and the joule heat of t he conductor during the quench. It was verified that this method should be applied to the second quench detection system for the 100kWh SMES.