Experimental study and performance testing of a novel parabolic trough collector

Abstract

Summary This work presents an experimental evaluation of a new design of a parabolic trough solar collector (PTC). To maximize the energy yield, a solar tracking system is implemented. The thermal performance of the PTC at three outdoor test methods is evaluated. The new design essentially affects the balloon, the trunk, the insulation, the inner reflector, the glass, the upper plane reflector, and the cover. The system performance with bi‐axial orientation and an absorber with a glass‐covered envelope is compared with two other designs of mono‐ and bi‐axial orientation without a glass‐covered envelope. The tests of the PTC with an aperture area of 2.88 m2 were conducted in Tunisian weather conditions, and the results are compared with similar systems already published data in the literature. A dynamic simulation with TRNSYS software is developed to evaluate the system performance based on experimental results. An economic study to evaluate the system's feasibility is conducted. The results showed that the new design achieved a maximum temperature of 179°C in comparison to 134 and 120°C for the mono‐ and bi‐axial orientation without a glass‐covered envelope, respectively. Furthermore, in the new PTC design, the useful daily energy gain increased by 33% and 15%, and the system thermal efficiency increased by 8.9% and 5.8% in summer and winter, respectively, in comparison to the case of mono‐axial orientation without a glass envelope. Besides, the maximum useful energy gain and the instantaneous thermal efficiency in the new design were 22.6 MJ and 73.45%, respectively, in comparison to 17.93 MJ and 67.41% for the mono‐axial orientation without a glass‐covered envelope. The gross payback period of the system was found to be 3.3 years with an NPV of €5257 over the lifetime of the system.