Citation:
Abstract:
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 have been 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 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 has been demonstrated to enhance heat transfer and vapor fraction, thereby optimising the thermal performance of the system. Furthermore, the configuration that optimised steam generation was achieved through the utilisation of an absorber tube equipped with two rectangular longitudinal fins, displaying an aspect ratio of 0.5. The optimum thermal performance factor was found to be 1.58, which is 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.