in this research a flat plate solar air collector was investigated under direct solar radiation consisted of a slatted glass cover, perforated absorber aluminum sheets (porosity 0.0177, 0.0314 and absorber thickness of 2.5 mm). the effect of porosity on absorber efficiency of collector was evaluated. six levels of air mass flow rates (0.0056 to 0.0385 kg m-2 s-1) were adopted.average solar ener...

outdoor experiments on a once-through single glazed solar air heater with perforated metal absorber plate were conducted to determine the practical effect of absorber plate porosity as well as suction air flow rate on the collector thermal efficiency and its total pressure drop. three aluminum absorber plates were made perforated by drilling circular holes with different diameter/pitch ratios i...

Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. It is attributed to the formation of a very thin boundary layer at the absorber plate surface commonly known as viscous sub-la...

In the present work the efficiency of a solar parabolic trough has been investigated experimentality. parabolic trough solar collector constitute a proven source of thermal energy for industrial process heat and power genaration. The impact of  using the partially porous media in the absorber on the efficiency of PTC (parabolic trough collector) has been investigated. The porosity of copper foa...

Current solar to thermal energy conversion technologies, including concentrated solar power (CSP) and solar water heaters (SWH) utilize absorber surfaces that collect incident solar radiation. However, these absorber surfaces emit thermal energy (at their temperature) in the infrared (IR) spectrum, resulting in decreased overall efficiency for solar-to-thermal conversion. Selective absorber sur...

This paper presents an analysis of the performance of a pancake absorber with a helical heal exchanger for use with point focus solar concentrating collectors. Th e principal difference between this type of absorber and most other concentrating solar collector absorbers is that the intensity of concentrated radiation monotonically increases from the inlet to the outlet of the heat exchanger tub...

In this investigation, the performance of an existing heating system of a residential building incorporated with an array of solar thermal collectors was studied. For this purpose, transient systems simulation program model was assembled to estimate the hour-by-hour performance of the existing and the system equipped with the solar thermal collectors in terms of the provided space air condition...

ABSTRACT The use of a thermoelectric generator (TEG) in generating useful power from solar thermal energy is demonstrated. This device represents a portable and autonomous power generation system operating from solar power, capable of powering micro/nano systems. The TEG was integrated with a micro solar thermal collector plate to enhance the thermal radiation absorption capacity of the hot sid...

The most common approaches to generating power from sunlight are either photovoltaic, in which sunlight directly excites electron-hole pairs in a semiconductor, or solar-thermal, in which sunlight drives a mechanical heat engine. Photovoltaic power generation is intermittent and typically only exploits a portion of the solar spectrum efficiently, whereas the intrinsic irreversibilities of small...