Abstract: The electric boiler has long been adopted as the standby steam source for the auxiliary steam system in nuclear power plants. Recently the immersion-type electrode boiler has become the preferred design, while its power control mode is changed from positive direct voltage regulation control to steam-water parameter reverse indirect control. As the“immerged electrode + reverse indirect control” is firstly adopted in Haiyang Nuclear Power Plant, in this thesis the mechanical and electrical structure of the boiler is presented with the heating principle being analyzed. Then, the control mathematical model is established to study and propose the control method.

Key words: electrode, liquid level, conductivity, temperature, pressure, electrical power