Comparison of Dynamic PTC Thermal Models Using Semi-Analytical and Finite Volume Methods

BAYER Ö., Uzgoren E.

ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, vol.37, no.3, pp.1191-1200, 2018 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 37 Issue: 3
  • Publication Date: 2018
  • Doi Number: 10.1002/ep.12773
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1191-1200
  • Middle East Technical University Affiliated: Yes


Resource potential estimation of concentrating solar power (CSP) applications with parabolic through collectors (PTC) needs to address time-dependent heat transfer fluid (HTF) temperature at collector field's outlet. HTF temperature distribution depends on several time-dependent variables; i.e., HTF temperature at PTC inlet, direct beam radiation, HTF flow rate and its properties, and PTC parameters, i.e., overall heat transfer coefficient. The present paper develops a time-dependent one-dimensional thermal model for PTCs using the analytical solution of governing partial differential equation assuming time-invariant material properties, inlet temperature, and incident irradiation. Time-dependency component is then integrated into the analytical solution using a time advancing numerical scheme. The results are presented in a generalized non-dimensional form, which features familiar parameters, i.e., NT U. It is shown that in contrast to the developed semi-analytical method, mesh-based methods suffer from an additional error source due to smoothening around t* = 1. As a result, it is also showed that the developed method can use time steps 10 to 25 times larger than mesh-based methods that achieve similar accuracy levels. In addition, developed method's each time-step is found to be about 13 times faster. The combined speed-up is identified as 130-325 for PTC simulations that have high variations in inlet temperature. (C) 2017 American Institute of Chemical Engineers