Browsing by Author "Dahiya, Anurag"

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Condensing heat transfer coefficients of R134a in smooth and grooved multiport flat tubes of automotive heat exchanger: An experimental investigation
(2019-05-01)
Ammar, Syed Muhammad
;
Abbas, Naseem
;
Abbas, Saleem
;
Ali, Hafiz Muhammad
;
Hussain, Iftikhar
Condensation heat transfer coefficient of R134a was obtained in multi-port micro channel smooth and grooved flat tubes of automotive heat exchanger. The test consisted of two smooth and one grooved tube. The test range covered mass flux 490-1600 kg/m(2) s, heat flux 5.5-19 kW/m(2) and saturation temperature 51-68 degrees C. Results revealed that condensation heat transfer coefficient increased with an increment of mass flux, vapor quality and decreased with the increase of saturation temperature. The effect of heat flux on heat transfer coefficient was negligible. The grooved tube showed larger heat transfer coefficient than that of smooth tubes. A comparison of the present data of flat tube with existing correlations revealed that the heat transfer coefficient was not reasonably predicted, therefore new correlation was developed for heat transfer coefficient that predicted 86% data within +/- 30% with a mean error of 16%. (C) 2019 Elsevier Ltd. All rights reserved.
Cost effective cooling of photovoltaic modules to improve efficiency
(2019-09-01)
Sajjad, Uzair
;
Amer, Mohammed
;
Ali, Hafiz Muhammad
;
Dahiya, Anurag
;
Abbas, Naseem
This study presents the performance of solar photovoltaic modules provided with cooling in terms of its normalized power output, performance ratio, and module efficiency. The aim of the study is to improve the performance, efficiency, and development of an economical cooling system by installing photovoltaic modules on the duct of cooled air of air-conditioners being used in most of the houses, offices and other buildings. The performance was researched and compared for two photovoltaic modules, one being cooled and other without cooling. The module being cooled showed 7.2% and 6% higher electrical efficiency and performance ratio respectively compared to the module without cooling. The results obtained in this study comprehend the importance and feasibility of the research.