Optimal Layout Design Method For Dish Stirling Solar Power System

Huge consumption of fossil fuels that powers the rapid grouth of economy gives rise to concerns on enviroment and energy crisis.Solar energy application is one of the promising directions toward these issues,which attracts research efforts from all contries.Comparing to photovoltaic,solar thermal energy applications have some unique advantages,including high and non-descreasing conversion efficiency and low polution during manfacturing.Despite of these advantages,this technique has not been widely used,due to immatureness of the technique,high investment on construction and low economic profits.Any break through these questions can advance its application.This thesis focuses on providing a method that optimally designs the layout of SES 25 kW Dish Stirling solar power plant,leading to lowest energy loss due to mutual shading among dishes.The main work and achievements are as follows:1.Establish mathematical modelallowing a quick and compute-based approach to calculate the shading rate of dishes.According to the principle of parabolic dish concentrator(the spindle points to the sun),we establish the local coordinate system with the dish as the origin and the sun direction as the z?-axis,convert the neighbor dishes to the local coordinate system and obtain the shape of shading which is the projection of dish along principal axis,without depending on sun position.According to the principle of shading effect: dishes near the sun can produce effect,we choose the suspicious dishes,thereby reducing the amount of calculation;combine with Stirling engine of the solar radiation response characteristics,propose the percentage of annual effective shading effect and establish the parametric representation which describes the condenser effciency loss due to dish-to-dish shading.2.To establish the parameter representation of different dishes layouts,and propose a method to design a global optimal dish layout.Based on the rectangular dish layout,we introduces the three parameters of the vertical relative displacement,counterclockwise rotation and scaling.In the case of land use rate unchanged,we calculate the percentage of annual effective shading effect of different dish layouts,which are transformed from the rectangular optimization layout in the parameter space(dish column spacing,offset,rotation).And the dish layout with the minimum annual effective shading effect percentage is the optimal layout.At the same time,we transform the the rectangular non-optimal dish arrays to obtain the optimized layout of each array,and obtain the global optimal layout by comparing the result with above-mentioned optimal layout's annual effective shading effect percentage.Then,we analyz the dish unit(the adjacent four dishes)and come to a conclusion: the percentage of annual effective shading effect is negatively correlated with the effective column spacing in the east and west direction of the dish.3.Propose factors need to be concerned during site selection of solar thermal power plant by studying the effects of the latitude and longitude and sun resources of different regionson the optimal dish layouts.Based on the meteorological data of different regions,we use the mathematical model to calculate the percentage of annual effective shading effect in the optimal layout of different cities,and get the rate of change of the annual effective shading effect percentage with the increase of the effective column spacing in the east and west direction.On the basis of this,we analyze the influence of the latitude and longitude and the sun resources on the optimal dish layout change rate of the installation site of the dish Stirling solar power system,and concludes that the installation of dish Stirling solar power system in regions with abundant sun resource,and the latitude and longitude of the system installation site does not affect the system benefits.Finally,the paper gives a summary,and puts forward the prospect of the future research work.