Workbench for a Parabolic Trough Solar Collector with a Tracking System.

Area of Science:

• Renewable Energy Systems
• Solar Thermal Technologies
• Energy Engineering

Background:

• Concentrated solar power (CSP) is crucial for renewable energy generation and CO2 reduction.
• Parabolic trough solar collectors (PTSCs) are a mature CSP technology with diverse applications.
• Ongoing R&D focuses on improving PTSC performance through advanced materials and designs.

Purpose of the Study:

• To develop and evaluate a low-cost parabolic trough solar collector (PTSC) suitable for academic and research purposes.
• To investigate the efficiency of the developed PTSC under varying temperature and flow conditions.
• To provide a functional, cost-effective platform for solar energy research and education.

Main Methods:

• Construction of a low-cost PTSC featuring a 120° edge angle, 2.2 m² aperture, and an unglazed copper absorber tube.
• Implementation of a two-axis active solar tracking system with photoresistive sensors and electric actuators.
• Development of a monitoring system with an interactive panel for real-time data visualization of temperatures and fluid flow.
• Laboratory testing using deionized water, analyzing efficiency at varied inlet temperatures (30-70°C) and flow rates (0.002-0.030 kg/s).

Main Results:

• The collector's efficiency was modeled as a function of temperature by the equation η = 0.324 - 2.47443 c', where c' relates inlet temperature, ambient temperature, and solar radiation.
• Optimal efficiency was achieved when the heat transfer fluid flow regime transitioned to turbulent.
• The developed PTSC exhibited lower efficiency compared to literature benchmarks, attributed to reflector diffusion and absorber tube thermal losses.

Conclusions:

• The low-cost PTSC is a viable educational tool for demonstrating solar thermal principles.
• Further research is needed to mitigate optical and thermal losses to enhance efficiency.
• The design provides a foundation for future improvements in low-cost solar concentrating technologies.