Simulation On Steam System Of The Secondary Loop Of Nuclear-Powered Plant

Simulation on steam system of the secondary loop of nuclear power plant is an important part of research of real-time, whole range, whole functional simulation of nuclear power plant. Dynamic simulation mathematic models for steam system of the secondary loop were established and validated in this paper. The main work and production of the paper are as follows,(1) Long diameter saturated steam pipes belong to active thermodynamic objects. Because steam in the pipes has humidity and volume inertia of the pipes is great, so two-phase fluid has violent mass and energy exchange and no-equilibrium thermodynamic process can happen in the pipes. Two-phase no-equilibrium tank model was established in the paper.(2) Short diameter saturated steam pipes belong to passive thermodynamic objects. Because of short diameter and fast flow of fluid, effect between the two-phase fluids can be ignored. Single-phase compressible fluid network model for the objects was established in the paper.(3) Heat evolution correction method for node of the saturated steam network was put forward, which can be used for simulation for large-scale steam network of nuclear power plant.(4) After analyzing the no-equilibrium characteristic of wet steam in turbine, author put forward that flow in cascade can be divided into two steps: no-saturated steam flow in cascade run and flow through oblique shock after cascades. A dynamic simulation mathematic model consisted of conservation equations of mass, momentum, energy, superheat steam equation, pressure drop equation, two-phase flows equations and relations before and after oblique shock. The model is a non-linear coupled equation.