Photovoltaic-thermal panel based on reversed circular flow jet impingement - pv magazine International

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Developed by scientists in Malaysia, the new PVT collector uses reversed circular flow jet impingement (RCFJI) as a cooling mechanism. Its creators claim the panel may be used for off-grid applications and the generated thermal energy could be used for drying purposes.

July 31, 2023 Emiliano Bellini

Researchers at the Universiti Kebangsaan Malaysia have designed a bifacial photovoltaic-thermal (PVT) panel that utilizes circular jets impinging as a cooling medium.

“We have fabricated a prototype for lab-scale purposes,” the research's corresponding author, Adnan Ibrahim, told pv magazine. “However, the proposed cooling technique, called reversed circular flow jet impingement (RCFJI), could be implemented in real applications according to the module sizes used by the user.”

The system consists of a reversed circular flow cup placed at a distance of 25 mm below the back of a jet plate with 36 jet plate holes, each measuring 3 mm in diameter. The air enters the air inlet, circulates through the RCFJI cup, and leaves then the jet plate with high velocity, causing impinging effects on the bifacial module.

“The impinging effects enhance the heat transfer rate, thus cooling down the bifacial module temperature and enhancing the photovoltaic efficiency,” Ibrahim said. “In addition, the air outlet is converted into thermal energy.”

The reversed circular flow jet impingement was fabricated through a 3D printing process using polylactic acid filament, which the scientists said eased fabrication and cost. “The polylactic acid filament can withstand temperatures up to 110 C while the PVT collector does not exceed 60 C,” Ibrahim added.

The PV panel has a size of 698 mm x 619 mm and uses 12 monocrystalline solar cells with dimensions of 156 mm x 156 mm. It has a nominal power of 60 W, an open-circuit voltage of 22.12 V, and a short-circuit current of 3.71 A.

The researchers tested the PVT panel under different solar irradiance between 500 W/m² and 900 W/m². They found the collector achieved the highest photovoltaic exergy of 47.2 W at 900 W/m², while the lowest of 28.1 W was reached at 500 W/m². “Across the range of 500–900W/m², the photovoltaic exergy values were determined to be between 24.88 and 27.18W, 29.45–32.34W, 33.89–37.40W, and 38.20–47.27W, respectively,” they explained.