Browsing by Author "Muneeshwaran, M."

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Performance improvement of photovoltaic modules via temperature homogeneity improvement
(2020-07-15)
Muneeshwaran, M.
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Sajjad, Uzair
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Ahmed, Tanveer
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Amer, Mohammed
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Ali, Hafiz Muhammad
Though the PV module performance can be enhanced by cooling, the associated temperature nonuniformity across the PV panel can deteriorate its efficiency. In this study, a significant effort is conducted for an air-cooling system that can control the temperature uniformity across the PV panel. The cooling of a rooftop PV module is enabled by the air-conditioning unit installed on the building's roof. PV panel performance, with and without the cooling, is experimentally investigated for the uniform cold air duct. Experimental results showed that the cooled panel temperature is 6-12 degrees C lower than that of the uncooled one. However, even with the cooling, the temperature non-uniformity of 4-7 degrees C was noticed across the PV panel. To improve the temperature uniformity across the module, converging cold air ducts with different area ratios (AR) of 0.667 and 0.333 were designed and analyzed numerically. The effect of inlet air temperature (Tin-air = 18-23 degrees C) and inlet airflow velocity (U = 2-3 m/s) on panel temperature were also studied. The results suggested that the PV panel with CCD having an AR of 0.333 exhibited a temperature non-uniformity of 1.5-2.5 degrees C and demonstrated a 17-22% improvement in module efficiency under Tin-air = 18 degrees C and U = 3 m/s. (C) 2020 Elsevier Ltd. All rights reserved.
Thermal design aspects for improving temperature homogeneity of silicon wafer during thermal processing in microlithography
(2020-05-05)
Muneeshwaran, M.
;
Wang, Chi-Chuan
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機械工程學系
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Department of Mechanical Engineering
Stringent temperature control is of great importance in the post-exposure baking of the lithography process, and this is usually maintained through the lamp heating and multizone heating method, which demands a precise control system. There is a vast scope for the wafer temperature homogeneity improvement by considering the thermal aspects in bake station design. In this study, both an experimental and a transient numerical analysis are carried out to examine the factors that could seriously affect the temperature uniformity of the wafer during the baking process. It is found that the guide plate arrangement, guide plate slope, and the air gap between the lid and hot plate play a critical role in controlling the wafer temperature uniformity. On this basis, some further improved bake stations are proposed to attain a better temperature homogeneity across the wafer. The performance of the improved designs is analyzed numerically. Yet, a better design based on the simulation is developed and tested experimentally. The new design features a 2.5 degrees guide plate with the funnel arrangement subject to the air gap condition, offering a temperature homogeneity within 0.2-0.3 degrees C on a 6 '' wafer.