Equipment Optimization And Dynamic Simulation Of Marine Secondary Circuit Condensate Feedwater System

The space on the ship is very limited,so the ship nuclear power system equipment is required to be light in weight and small in volume.Moreover,the load of the ship nuclear power device varies sharply and widely during operation,so the ship nuclear power system is required to respond quickly and have high stability.As an important water system in the nuclear power secondary loop system,the volumetric inertia and thermal inertia of the condensate feed water system are very important for the response characteristics of the whole Marine nuclear power secondary loop system.Therefore,it is of great theoretical and practical significance to use optimization technology to carry out multi-objective optimization research on the weight and volume of the main equipment in the condensate water supply system and to study the dynamic characteristics of the condensate water supply system by simulation means.This paper takes the marine nuclear power secondary circuit condensate feed system as the research object.Based on the working principles of the equipment in the system,the main condenser and deaerator are thermally designed;the evaluation program of the main condenser and deaerator is compiled using Python language,At the same time,the reliability verification of the evaluation model was completed,and combined with the particle swarm algorithm,the dual-objective optimization design of the weight and volume of the main condenser and deaerator were realized.The optimization results show that compared with the parent model,the weight and volume of the main condenser are reduced by 28.72% and38.64%,respectively;the weight and volume of the deaerator are reduced by 14.08% and21.44%,respectively.The optimization results proved the feasibility of optimization of the marine main condenser and deaerator from a theoretical point of view,and pointed out the direction for future optimization.Build and debug the simulation model of the nuclear power secondary loop system based on the optimized equipment,and complete the steady state verification of the system under high and low load conditions.Carry out the simulation research on the dynamic characteristics of the condensate water supply system under the condition of gravity cooling,the thermal performance of the main condenser and the power of the main steam turbine are affected by the seawater temperature and the cooling water flow rate;the high-speed condition of the self-flow cooling is studied The influence of seawater temperature changes on the characteristics of the secondary circuit system under conditions and forced cooling.The simulation results show that the load stabilization time of the condensate feed-water system under gravity cooling is 1600 s,and the stabilization time of load drop is 1400 s.The tracking ability of the condensate feed-water system under variable load conditions is better;the main steam turbine power is kept unchanged under the gravity cooling condition.As the seawater temperature rises,the pressure of the main condenser rises,and the steam consumption of the main steam turbine increases;when the seawater temperature drops,the pressure of the main condenser drops and the steam consumption of the main steam turbine decreases.Under forced cooling conditions,with the continuous increase of the cooling water inlet temperature,the supplementary cooling water flow required by the circulating cooling water pump is also increasing;and the higher the initial cooling water inlet temperature,the more supplementary cooling water flow is required to be provided.When the circulating cooling water temperature rises from 22°C to 24°C,the cooling water flow rate required by the circulating cooling water pump is 10.65%;When the temperature rises from 22℃ to 26℃,the cooling water flow required by the circulating cooling water pump increases by 12.67%compared with that provided by the temperature rises to 24℃.The simulation results provide a theoretical basis for the practical operation guidance of the secondary loop system,the optimization of the control system and the formulation of the optimal operation scheme of the circulating pump.