Optimization Design And Aiming Strategy Of The Heliostat Field And Receiver Subsystem In A Solar Tower Power Plant

In a solar power tower plant,solar radiation is reflected by the heliostat field and concentrated in the receiver at the top of the tower to provide energy for conventional thermodynamic cycle.The concentrating and receiving subsystem,consisted of the heliostat field and the receiver,takes up most part of construction invest.Moreover,the optical efficiency of the heliostat field and the thermal efficiency of the receiver have critical influence on the total power output.Therefore,the optimization design and operation of concentrating and receiving subsystem is of great importance to reducing the equipment cost,improving the power generation efficiency and ensuring the stable operation.The main contributions of this thesis are as follows(a)An optimization of heliostat canting based on optimal paraboloid canting method is proposed dealing with the spillage problem of large heliostats.A two-stage method combining particle swarm optimization and direct search method based on quadratic fitting model is proposed to solve the optimization problem.The simulation results of PS 10 plant demonstrate that the canting method with the optimal parameter can reduce spillage loss effectively(b)An optimization method to design the receiver is proposed.The heat loss model of the receiver is built and several key parameters including the receiver cavity and panel size are selected as decision variables to build the optimization model with the objective to reduce the levelized cost of the receiver.An Adaptive Particle Swarm Optimization combined with Smart Sampling Monte Carlo method is proposed to improve the solving speed.Simulation results show that the optimization method can reduce the levelized cost of the receiver significantly(c)A multi-point aiming strategy is employed to get a uniform flux distribution and maximize the total power on the receiver panel.A fast solving method of the nonlinear integer program is proposed.The heliostats with the most spillage are selected to change aiming point and their reflected power is precalculated.With the energy distribution variance constrain relaxed,the linear integer subproblem is built The amount of heliostats that changing aiming point is iteratively increased until the flux uniform distribution constraint on the receiver is satisfied.The simulation results show that the aiming strategy can achieve uniform flux distribution and solve quickly to meet the demand of real time control.