Fabrication and assessment of a parabolic dish con-centrator using a water heater cylindrical receiver

This study presents a novel approach to fabricating a low-cost solar parabolic dish concentrator with one-meter-long glass/silver mirrors on the reflecting surface. The concentrator's parabola curve is made of four layers of fiberglass needle felt and polyester resin. The parabolic dish surface is mirrored vertically with 2 mm thickness glass/silver mirrors with a width of 5 cm and a length of one meter attached with silicone glue. The system is assembled and tested at the Sharif University of Technology in Tehran, Iran. Energy and exergy efficiencies are calculated using cylindrical water heater receiver data. These data are used to calculate the receiver’s absorbed energy and losses. Test results show that the major energy loss is due to convection. The average energy efficiency and the maximum exergy efficiency of the concentrator are 57% and 67%, respectively. The maximum power absorbed by the water is 1656.8 W at midday, and the maximum temperature observed on the receiver is 540 ̊C. Finally, a discussion is held to propose ideas to improve the fabrication process of the designed parabolic dish concentrator. This type of fabrication is suitable for regular thermal applications. However, several deficiencies are detected, and a few solutions are suggested. Mirror edges and flexibility are two of the parabolic dish's major defects.