Abstract

The objective of this study is to determine the energetic and exergetic enhancement of parabolic trough collector with internal fins in the absorber. Carbon dioxide is the examined working fluid to investigate the performance of the system in high temperature levels. In the first part of this study, the impact of the mass flow rate on the collector performance is analyzed and finally 0.20 kg/s is selected as the most appropriate mass flow rate exergetically. In the second part, the impact of internal fins on the system performance is investigated for operation with the optimum mass flow rate. More specifically, the absorber without fins is compared with three different fins with lengths 5, 10 and 15 mm. The final results prove that the higher fin length increases the thermal performance, while the optimum fin length exergetically is 10 mm with 45.95% exergetic efficiency when the inlet temperature is equal to 400 °C. The impact of the pressure losses along the collector is taken into account in the exergetic efficiency, which is the best index for evaluating solar collectors operating with gases. The analysis is performed with Solidworks Flow Simulation, a powerful tool which allows the simultaneous thermal and optical analysis.

Highlights

  • The increasing rate of the worldwide energy use is one of the most crucial threats of the recent years due to fossil fuel depletion [1], greenhouse gases emissions [2] and the population increase

  • The final results prove that the higher fin length increases the thermal performance, while the optimum fin length exergetically is 10 mm with 45.95% exergetic efficiency when the inlet temperature is equal to 400 °C

  • Kasperski and Nems [21] investigated multiple-fin arrays to enhance the thermal performance of parabolic trough collectors operating with air and they proved performance increase close to 14%

Read more

Summary

Introduction

The increasing rate of the worldwide energy use is one of the most crucial threats of the recent years due to fossil fuel depletion [1], greenhouse gases emissions [2] and the population increase. The use of PTC in concentrating power plants, in industrial processes, in hydrogen production and in other similar high temperature applications is more and more usual the last years [8]. A lot of interest has been given in the use of gas working fluids in PTC, as air, nitrogen, helium and carbon dioxide. These gases can be used at temperature levels close to 500–600 °C and up to 1000 °C in some cases. Bellos et al [9] examined six gas working fluids (air, nitrogen, carbon dioxide, helium, argon and neon) exergetically and carbon dioxide was proved to be the most efficient working fluid in high temperature levels. Al-Sulaiman and Atif [13] examined the use of carbon dioxide in supercritical Brayton cycles coupled with solar tower technology and Coco-Enrıquez et al [14] with parabolic trough collectors

Objectives
Results
Discussion
Conclusion

Full Text

Published Version
Open DOI Link

Get access to 115M+ research papers

Discover from 40M+ Open access, 2M+ Pre-prints, 9.5M Topics and 32K+ Journals.

Sign Up Now! It's FREE

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call