Study On Control Strategy Optimization Of Condensate Feedwater System In Nuclear Power Secondary Loop

Marine nuclear power secondary loop system has complex composition,frequent load changes and large amplitude in dynamic operation,and great disturbance to the power system.Condensate feed water system is one of the most important components of nuclear power plant.The design of reasonable control strategy is of great significance to the safe and stable operation of nuclear power secondary loop system.This paper takes nuclear power plant as the research object,establishes the mathematical model of nuclear power secondary loop system,completes the overall development of simulation model,and verifies the accuracy of the model by comparing the steady-state simulation data with the theoretical design data.Three control strategies are designed,developed and studied in the case of abnormal water level of Deaerator and condenser,the regulation power and system stability,and the effect of different control strategies on water level regulation of Deaerator and condenser and the regulation capacity of the system in the case of ascending and descending conditions.The simulation results show that the effect of C-PID control is better than that of ordinary PID control in regulating the abnormal water level of condenser in the process of regulating the abnormal water level.The optimized C-PID control scheme achieves 35.00%,37.5%,44.44% and 4.00% respectively in the first to fourth pairs of experimental conditions.D-PID control scheme is superior to C-PID control scheme in regulating abnormal water level of deaerator.During the process of deaerator water level restoring to stability,its trend of change can converge obviously.D-PID control scheme has less overshoot than C-PID control scheme in regulating abnormal water level.The optimum results of the deaerator water level overshoot are 71.05%,67.65%,47.62% and 38.89% respectively in the first to fourth and 0-500 seconds of the experimental conditions.D-PID control strategy is superior to W-PID control strategy in adjusting water level of deaerator,but inferior to W-PID control strategy in adjusting water level of condenser.During the load-raising process,the water level overshoot of deaerator is reduced by 0.015,the stabilization time is shortened by 100 s,the water level overshoot of condenser is increased by 0.005 and the stabilization time is increased by 400 s under the regulation of D-PID control strategy;during the load-reducing process,the water level overshoot of deaerator is reduced by 0.047,the stabilization time is shortened by 500 s,the water level overshoot of condenser is reduced by 0.001 and the stabilization time is increased by 200 s.The disturbance of W-PID control strategy to daily water tank is less than that of D-PID control strategy,but the waste of chemical replenishment water is serious.