The analysis are made for various hot oil flow rates and fluid temperatures at solar noon hour of 4 days of Autumnal Equinox, Winter Solstice, Spring Equinox and Summer Solstice as critical design conditions. In this article, three dimensional non-uniform flux density, temperature distribution and thermal expansion of the absorber tube of two types of Shiraz solar thermal power plant collectors which leads to the absorber tube deflection are determined numerically. When a tube deforms, it will go out of focal point and causes different problems such as decreasing the life time of collector, breakage of cover glass tube and also it drops optical efficiency of the collector.
Deformation of the absorber tube takes place due to a non-uniform thermal expansion, such as shown in Fig. Accurate studies are needed to find three-dimensional temperature distribution of the absorber tube and its thermal expansion and deformation for any safe and efficient operation. The temperature increase depends on the geometrical concentration ratio (Gc) and optical properties of the collector as well as fluid flow in the absorber tube. For a tube in focal point of the parabolic collector, solar absorption will heat the tube and so temperature of the tube wall will rise. Solar technology for electricity generation can be made by various systems, among them parabolic trough collectors are the most installed plants around the world. Solar thermal electricity generation is not yet competitive with fossil fuels in some countries but it is economically one of the feasible renewable technologies of the future. Final manuscript published as received without editorial corrections.
Selection and peer review by the scientific conference committee of SolarPACES 2013 under responsibility of PSE AG.
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This is an open access article under the CC BY-NC-ND license (). Keywords: Parabolic trough collector, flux density distribution, thermo-elastic analysis, ray tracing, bending Selectionand peerreviewby thescientificconference committeeofSolarPACES2013underresponsibilityofPSEAG. Appropriate flow rate and convection coefficient for each season are found in order to decrease tube bending, prevent optical efficiency drop of collectors, keep high factor of safety, and reduce cyclic daily amplitude motion which lead to longer life time of absorber tube.ģD Thermal-structural analysis of an absorber tube of a parabolic trough collector and the effect of tube deflection on opticalĪM.Sc., Mechanical Engineering Department, Shiraz University, Shiraz, Iran bProf., Mechanical Engineering Department, Shiraz University, Mollasadra Street, Shiraz 71348-51154, Iran Results of the local concentration ratio, flux density, temperature distribution and thermal expansions are determined for the designed conditions. Thermal stresses and strain are determined for two types of collectors first one is a constructed collector and second one is under construction at Shiraz (Iran) solar thermal power plant. The governing equations of thermo-elastic constitutive are solved in three dimensions for steady state thermal and static structural analysis with appropriate boundary condition using Finite Volume and Finite Element numerical codes. The local concentration ratio for the parabolic trough collectors, which is a key boundary condition in the thermal analysis is computed by Monte Carlo Ray Tracing method for different conditions.
Three dimensional temperature distribution and tube thermal expansion due to non-uniform solar flux over the tube are determined numerically. In this paper deformation rate of an absorber tube of a parabolic trough collector due to a 3D solar flux density distribution is studied theoretically. Abstract of research paper on Materials engineering, author of scientific article - S.M.