Determination of Reasonable Pressure in Moisture Separator Reheater of Wetted Steam Turbine Unit using Structure Variables Revealing Heat System

We established the model for calculating the heat system and the optimization model for calculating the electrical efficiency by means of the variables revealing the system structure in the wetted steam turbine unit and determined the reasonable pressure in the moisture separator reheater by using the genetic algorithm. The pressure in the moisture separator reheater is varied with the composition of each heat system, different capacities and state parameters in the inlet and outlet of turbines. The relation between the model of a feed water heater and the variables revealing the system structure was considered and the mathematical model and optimization model with the structure variables for the heat system of the wetted steam turbine unit were suggested. And the absolute internal efficiency of the wetted steam turbine unit was taken as the objective function and the pressure in the moisture separator reheater was determined to maximize the objective function. In the genetic algorithm, the pressure in the moisture separator reheater, pressures of the extraction steam and structure variables were taken as the determinant variables and genetic operations such as selection, crossover, and mutation were carried out. Based on the obtained mathematical models, the reasonable pressure in the moisture separator reheater in the 1000MW wetted steam turbine unit was determined by using the genetic algorithm. The optimization method suggested in this work may help designers of new nuclear power plants and operators to analyze the thermo economic efficiency of the nuclear power plant.