Experimental Study of a Newly Design Helical Coil Receiver in Evacuated Tube for Parabolic Trough Solar Reflector

Abstract Over the last decade, there has been significant interest in renewable energy resources, with solar energy emerging as one of the most promising options. Among various technologies, the parabolic trough solar reflector with innovative receivers plays a crucial role in efficient solar power harvesting. This experimental study focuses on a stationary parabolic trough with a 2.8 m2 aperture area, integrated with a manually operated dual-axis sun-tracking system. The primary objective was to evaluate and enhance the system's thermal performance over three representative days in February, under both sunny and cloudy conditions. To optimize optical performance while minimizing design and fabrication costs, the prototype incorporated mirror strips, which also helped reduce lift and drag forces caused by high air pressure around the trough. A three-day experiment was conducted to assess the system's performance, and the results demonstrated that the water's highest recorded temperature was 84.2 °C, while the regenerative air attained 75.1 °C using a novel helical-coiled receiver design. With a maximum receiver thermal efficiency of 85.4% and an overall system efficiency of 55.4%, the design exhibits considerable promise for integrated air and water heating applications in residential and industrial contexts.