Parametric investigation on the thermo-hydraulic performance of a novel solar air heater design with conical protruded nozzle jet impingement. (25th January 2023)

• Record Type: Journal Article
• Authors: Das, Supreme; Biswas, Agnimitra; Das, Biplab
• Is Part Of: Applied thermal engineering. Volume 219(2022)Part B
• Publication Date: 2023-01-25
• Subjects: Solar air heater -- Jet impingement -- Conical protruded nozzles -- Thermo-hydraulic performance -- Exergy analysis; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2022.119583
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Numerical analysis conducted on a novel jet impingement SAH using conical protruded nozzles. Thermo-hydraulic parameters compared with smooth SAH and other jet impingement designs. Implications of geometric parameters on the thermo-hydraulic performance investigated. Maximum thermal efficiency of 91.25% and maximum exergy efficiency of 3.55% obtained. Maximum enhancement of Nu and THPP obtained as 400% and 265%, respectively. Abstract: A numerical investigation is carried out on heat transfer behaviour of a novel solar air heater (SAH) design with impinging jets through conical protruded nozzles using CFD simulations. The impact of non-dimensional parameters is analyzed by varying the nozzle length ratio ( Ln /Dh ) from 0.0434 to 0.434, nozzle throat diameter ratio ( Dnt /Dh ) from 0.0217 to 0.1086 and nozzle base diameter ratio ( Dnb /Dh ) from 0.0434 to 0.1086 for Reynolds number (Re) variations from 2900 to 14300. The present results with jet impingement design have been compared with a conventional parallel flow SAH under similar conditions and also with some existing designs. Results show that for a combination of Ln /Dh = 0.2608, Dnt /Dh = 0.0217, and Dnb /Dh = 0.0652, the highest thermal efficiency of 91.25 % and exergy efficiency of 3.55 % are obtained at Re value of 14, 300 and 2900, respectively. Also, the highest Nusselt number (Nu) of 223.18 is observed for the same combinations at Re = 14300, whereas the highest thermo-hydraulic performance parameter (THPP) of 3.65 is observed for Re = 5740 owing to minimum pressure drop across the collector. With much improved thermal efficiency and THPP, the proposed design and the developed CFD model can be used for further development of impinging jet SAH design.