Influences of Optical Factors on the Performance of the Solar Furnace

Zhiying Cui,Zhifeng Wang,Fengwu Bai,Fuqiang Wang

doi:10.3390/en12203933

Abstract

In this paper, an optical structure design for a solar furnace is described. Based on this configuration, Monte Carlo ray tracing simulations are carried out to analyze the influences of four optical factors on the concentrated solar heat flux distribution. According to the practical mirror shape adjustment approach, the curved surface of concentrator facet is obtained by using the finite element method. Due to the faceted reflector structure, the gaps between the adjacent mirror arrays and the orientations of facets are also considered in the simulation model. It gives the allowable error ranges or restrictions corresponding to the optical factors which individually effect the system in Beijing: The tilt error of heliostat should be less than 4 mrad; the tilt error of the concentrator in the orthogonal directions should be both less than 2 mrad; the concentrator facets with the shape most approaching paraboloid would greatly resolve slope error and layout errors arising in the concentrator. Besides, by comparing the experimentally measured irradiance with the simulated results, the optical performance of the facility is evaluated to investigate their comprehensive influence. The results are useful to help constructors have a better understanding of the solar furnace’s optical behavior under conditions of multiple manufacture restrictions.

Highlights

In solar thermal power applications, the solar furnace has globally served as an ideal test-bed to develop key technologies required for high temperatures, and is used for its capability of concentrating solar radiation to factors of more than thousands of suns [1]
The solar furnace in PSA [6], named SF40, has a similar optical structure design to the one in KIER [7]. They are composed of a flat heliostat with a no-concentration effect and a revolution paraboloid dish, and achieve very high concentrated solar heat flux and thermal gradients
The Monte Carlo ray tracing (MCRT) codes are programmed in mixed programing languages, which should be validated before the further study

Summary

Introduction

In solar thermal power applications, the solar furnace has globally served as an ideal test-bed to develop key technologies required for high temperatures (up to 3500 K), and is used for its capability of concentrating solar radiation to factors of more than thousands of suns [1]. In Odeillo, France, the CNRS has been operating a 1000 kW thermal power solar furnace since 1968 It is known as one of the biggest solar furnaces in the world, consisting of 63 heliostats and a parabolic concentrator with an 1830 m2 aperture area [4]. The solar furnace in PSA [6], named SF40, has a similar optical structure design to the one in KIER [7]. They are composed of a flat heliostat with a no-concentration effect and a revolution paraboloid dish, and achieve very high concentrated solar heat flux and thermal gradients. Zhang et al [8] proposed a line-focused solar concentrating system to extend the possible

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Conclusion