Abstract:
House hold energy use for cooking from Ethiopian context is one of the critical issue
affecting the environmental safety and economic well-being of citizens. An
environmentally friendly and well-designed system plays a crucial role in reducing those
problems and conserving the environment. In this thesis, design, manufacture and
experimental investigation of solar cooker with heat storage is presented. The cooker is
designed in a way to make suitable for indoor cooking by storing the collected solar
thermal energy with specifically selected storage medium. The device was designed for
indoor cooking application and experiments were performed both for the storage devices
(material) and the overall cooking system. The cooking system has parabolic dish
concentrator, thermal storage device (sensible heat storage) and one axis manual solar
tracker. The prototype of the parabolic dish concentrator was done by aluminum sheet metal reflector with iron frame and it has an area of 11309.73cm2, focal length of 25.7cm
with concentration ratio of 15.8. The storage system has been developed in rock + sand
and engine oil which have mass of Rock + sand = 900g and Engine oil =700g. The
experimental investigation of the storage system was done first using electrical heating as a source of energy and solar energy during field test. The 1st investigation was done
using house hold electrical stove and the recorded storage media temperature for charge time up to one hour was 135℃ and for discharge time up to two hour was 96. The 2nd investigation was done using solar energy from parabolic dish concentrator and the recorded storage media temperature for charging time up to one hour and half minute was 96℃℃with cooking power or thermal efficiency of 18.5 and for discharge time up to fifty minute was 74℃. Manual one axis solar tracker is designed and made from angle iron with compatible dimension for parabolic dish concentrator; it has the dimensions of 35 cm width, 100cm height and 120cm length with enough strength for holding storage
system at focal point. The experimental investigation mainly targeted at identifying the
time rate of charging and discharging capacity of the thermal energy storage system
(sand + rock and engine oil). Generally, the proposed system can be used during off
sunshine periods and has a vital role in reducing indoor pollution and the burden
associated with fuel wood gathering.Design, manufacture & experimental investigation of solar cooker with heat storage.