Optimization of Solar Power Plants through Enhanced Direct Steam Generation in Parabolic trough Absorber Tubes using Passive Heat Transfer Techniques

Solar power plants that incorporate parabolic trough collectors (PTC) to generate solar energy can be regarded as a viable alternative to conventional power plants. To enhance the performance and productivity of these systems, it is imperative to improve the direct steam generation process. This study proposes the implementation of a passive enhancement technique to improve steam production in the PTC absorber, with the aim of optimising the overall size and cost of solar power plants. For this purpose, longitudinal fins were attached to the inner bottom part of the tube. A numerical investigation was conducted to examine the two-phase flow with vaporisation using the ANSYS Fluent code. The analysis of the two-phase flow was carried out via the volume of fluid technique. Additionally, a phase-change model was integrated to elucidate the vaporisation process. The Monte Carlo ray-tracing approach was employed to identify the irregular distribution of heat flux across the tube. The integration of fins within the absorber tube was shown to enhance heat transfer and vapor fraction, thereby optimising the thermal performance of the system. Furthermore, the configuration that maximised steam generation was achieved through the use of an absorber tube equipped with two rectangular longitudinal fins, displaying an aspect ratio of ۰.۵. The optimum thermal performance factor was found to be ۱.۵۸, which was reached in the laminar regime. The study's findings indicate a reduction in the overall dimensions of the PTC absorber, leading to a decrease in the size of solar power plants and their associated costs.

کلیدواژه ها:

Enhancement technics ، VOF model ، solar collector ، Two-phase flow ، Direct steam generation ، Monte-Carlo Ray Tracing technique