Performance analysis of a solar parabolic trough collector fitted with a helical coiled tube absorber

The SPTC is used for medium- and high-temperature applications. Several works are carried out for the enhancement of heat transfer of SPTC using size variation, absorber with inserts, nanofluid with working medium and different configurations of the absorber. The development of turbulence effect in the working fluid is important for heat transfer enhancement. Therefore, a novel idea is introduced to use a helical coiled tube absorber in the PTC, which enhances the heat transfer between the tube and the flowing fluid by providing swirling motion. The current research work uses the helical coiled tube absorber which consists of 42 turns and 2 m in length, 10 mm in internal diameter and 12.5 mm in outer diameter. It is enclosed by a glass envelope to reduce thermal losses. The experiments are conducted by varying the mass flow rate of water from 0.01 kg s−1 to –0.03 kg s−1. The maximum achieved useful heat gain, water temperature and instantaneous efficiency are 800 W, 64°C and 56%, respectively while using the flow rate of 0.01 kg s−1. © 2022 Informa UK Limited, trading as Taylor & Francis Group.