The present study investigated the impact of weather conditions on the production performance of the photovoltaic (PV) module. The experiments have been conducted by using two identical PV module of 75 Watt each and they were placed in the same weather conditions in the summer season in Kirkuk city-Iraq. One of them was used as a conventional module as a reference panel and the other unit which has been used in all required tests. Water circulation has been used for cooling of the PV module to and very fine soil used to estimate the effect of each of hot weather and dust deposition on the performance of PV respectively. The results show that the fill factor (FF) and PV efficiency affected inversely with increasing in temperature, on the other hand cooling process contributed to increase the voltage generation across PV panel by 11.8%, while the reduction in voltage generation by unclean panel due to natural pollution deposition on the front of the panel for a period of three months was about 3.8% compared with clean panel and 13.8% if it has been compared with voltage production by panel when it has been cooled by water.

The mass flow rate and Rayleigh number has been investigated experimentally on the passive solar using Trombe wall consist of (industrial wax) used as phase change material (PCM). A test rig of a cubicle was made of PVC sandwich panel except the south wall, Trombe wall; covered with a clear glass of 6 mm thickness. The six experiments were carried out during the winter season in Kirkuk city with six different widths of the air gap channel (10, 15, 20, 25, 30, and 35) cm. The experimental resultts show that the mass flow rate proportional directly to a width of the channel and inversely with Rayleigh number. Moreover, the highest efficiency was obtained at a depth of 30 cm, where it was about 2.45 times the efficiency of 10 cm.

This study examines the selection of the best air gap to a model solar passive solar system chosen for heating in a cold climate based on instantaneous efficiency. The experiments have been performed on a passive solar system, which has been constructed from insulation sandwich panels in all sides except the south façade, which has been built from insulation sandwich panels on all sides except the south façade, where Trombe wall has been built in it, which is constructed from reinforced concrete and their exterior surface has been painted with dark black color, and covered with a single transparent glass layer. Five sets of experiments have been performed on the test system by changing the width of the air gap from 30 to 10 cm under the weather conditions in January 2017 in the city of Kirkuk (Iraq). The experimental results have showed that the 33 to 36% of the absorbs energy by Trombe wall has been converted to instantaneous energy provided to the heating space during the day. In addition, the results of the energy analysis of experimental equations have been produced to assess the efficiency of the system; they show that the 15 cm air gap has a better case when applying the same parameters, this result is consistent with an experimental study conducted by R. L. Casperson and C. J. Hocever, 1979. Copyright © 2019 Praise Worthy Prize - All rights reserved.

A heat sink is a device that helps absorb or dissipate heat from the surrounding area using extended surfaces or fins in various geometries. This technology finds its applications in various thermal applications, including power plants, refrigeration, air conditioning systems, electric and electronic devices, and chemical industries. The most common type of heat sink is a metal device with many cooling fins, known as a fin array. There are two methods used to cool heat sinks: passive and active. Increasing the surface area of the fins' thermal conductivity, or heat transfer coefficient, can enhance the performance of the heat sink. There are various profiles for longitudinal fins, including parabolic, triangular, and rectangular shapes. The most popular profile is the rectangular one, particularly in arrays with multiple fins. The purpose of this study is to review the optimization design of longitudinal rectangular fins for arrays with one or more fins subjected to both natural and forced convection.