Design Variable Analysis of ALIP for the Circulation of Sodium in the IHTS of PGSFR

Abstract

The design variables of the Annular Linear Induction electromagnetic Pump (ALIP) were analyzed for the circulation of liquid sodium in the Intermediate Heat Transport System (IHTS) of the Prototype Generation-IV Sodium cooled Fast Reactor (PGSFR) of 150 MWe, which is being developed in the Korea Atomic Energy Research Institute (KAERI). Electromagnetic pumps have been employed for the transportation of the liquid metal with high electrical conductivity such as sodium, lithium and lead bismuth. An electromagnetic pump is developed by Lorentz’ force generated from driving current and magnetic field perpendicular to it. It is operated without any contact with liquid metal because of no rotating part like the impellor and sealing while a mechanical pump transports liquid metal using impeller which contacts with the liquid metal. The change of physical property including the decrease of strength or corrosion can be caused by the contact between impeller and liquid metal. Therefore, in the sodium fast reactor (SFR), an electromagnetic pump can be effectively used in the environment of sodium with the high chemical reactivity avoiding direct contact with sodium due to the advantage of structural simplicity by no sealing over mechanical pumps. In this research, the design variables of the ALIP, which was composed of a stator core, exciting coils and duct wall, with the flowrate of 0.86 and developed pressure of 3.6 bar were analyzed magnetohydrodynamically according to the change of geometrical, hydrodynamic and electromagnetic ones. The maximum length and diameter of the ALIP were limited to 3 m and 2.2 m, respectively, because of geometrical restriction of the space. The condition for the minimum thickness of the outer duct and inner duct of the pump was set to 0.015 m and 0.025 m taking into thermal property of the stainless steel duct material, respectively. The developed pressure and efficiency of the pump were analyzed on the changes of pump geometrical and electromagnetic variables solving MHD equations, where the commercially used software of MATLAB was employed for the calculation. The magnetic field, linear current density and pressure loss were dependent on the flowrate of the pump. The dominant factors affecting on the pump performance were core length, flow gap, number of pole pairs, pole pitch. The P-Q characteristic curves were theoretically predicted on the change of the input current, voltage and power for the pump with the optimized design variables.