Photovoltaic-thermal system combined with wavy tubes, twisted tape inserts and a novel coolant fluid: energy and exergy analysis

Abstract

To create a highly efficient photovoltaic-thermal (PV-T) system and maximise the energy and exergy efficiency, this study aims to propose an innovative configuration of a PV-T system comprising wavy tubes with twisted-tape inserts. Following the validation of a numerical model, a parametric study has been conducted to assess the geometrical effects of twisted tape and wavy tubes, as well as the coolant fluid type and velocity, on the overall performance of a PV-T system, located in Shiraz, Iran. It is found that employing twisted tape improves the energy and exergy efficiency by approx. 6.3%. The best configuration yields 12.4% and 16.8% increase in energy and exergy efficiency compared to conventional PV systems. This is achieved at 15% volumetric concentration of microencapsulated phase change material slurry. The monthly variation of global horizontal irradiance in Shiraz highly affected the energy and exergy efficiency of PV-T, with July and October exhibiting the most efficient months, corresponding to 90% and 11.3%, respectively.

Highlights

• Energy and exergy of photovoltaic-thermal system with twisted tape and wavy tubes.

• Reduction in the temperature of the PV panel by 8.3°C compared to the base case.

• 12.4% and 16.8% increase in energy and exergy efficiency in the optimum configuration.

• Higher energy and exergy efficiency from microencapsulated phase change material.

KEYWORDS:

• PV-T solar collector
• CFD
• energetic and exergetic efficiency
• twisted tape insert
• microencapsulated phase change material
• wavy tubes

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The corresponding author, Dr. Amir Keshmiri would also like to acknowledge the funding by the UK Engineering and Physical Sciences Research Council (EPSRC) under the Impact Acceleration Account (IAA) provided to the University of Manchester, which has supported the present research.