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In this paper, a numerical investigation had been performed to improve the melting process of phase change materials (PCM) by utilizing a trapezoidal channel. Different geometrical parameters of the trapezoidal channel were investigated. These parameters included: the height and pitch of the trapezoidal channel. Two-dimensional numerical models were developed with ANSYS (FLUENT) software. The unit is a horizontal channel that the heat transfer fluid (HTF) (hot water) passes through the channel to melt the PCM which contained at the top and bottom sides of the channel. The results showed that the trapezoidal channel with a longitudinal pitch of 6 mm and a height of 4 mm is the most suitable parameters for increasing the PCM melting process compared to other geometrical parameters. It was also concluded that the melting time is decreased by 27% at a height of 4 mm, and by 8% at a pitch of 2 mm.

The heat exchanger (HX) plays a key role for several industries, to reduce the energy consumption by rising heat transfer rate through heat exchanger. In this study, numerical simulation of shell and double tube heat exchanger without and with baffles is analyzed to evaluate the heat transfer and exergy analysis. A numerical simulation of 3D model with turbulent flow at the range (4000-12000) is performed with commercial computational fluid dynamics (CFD) software ANSYS (Fluent). The circular vents baffles model is used at the side of the shell. The simulation results show that the circular vents on the baffles of the heat exchanger have a significant impact on thermal- hydraulic performance and exergy analysis. Also, the results show that the heat exchanger effectiveness with baffles increases by 17% at high Reynolds number comparing with heat exchanger without baffles. Besides, the highest value of exergy loss reached to 42W with baffles presence. Finally, it is concluded that the heat exchanger with baffles gives better hydraulic and thermal performance than that of heat exchanger without baffles.

The present study investigates many parameters in the design of a residential building consisted of 6 floors with a construction area 240m2 located in Basra city. This study aims to reduce electric energy consumption utilized for cooling and heating of the building. The parameters which studied included: the effect of building façade, the exterior color of the external walls, the glazing distribution and the shape of the building. eQuest energy simulation program is used to simulate the annual building energy consumption, the program uses the hourly annual collected weather data. The results show that orientation the building façade toward the north direction is the best in the design of the building. The saving in annual electric energy consumption is about 11%. Moreover, the external color of the building has a strong effect on building cooling and heating energy consumption. By utilizing white exterior wall color, the annual electric energy consumption reduced by about 12%. The results also showed that by utilizing proper glazing distribution the electric energy consumption could be reduced by 3%. When all enhancements were combined an optimum building case were found. For the optimum case, the annual electric energy consumption was reduced by 35% compared to the base building case.

Iraq has suffered since decades from the shortage of supplying electric power o supply residential buildings. This research aims to study the orientation factor in the urban planning and its relation with the decrease of electric power consumption by reducing the cooling loads in summer season, which it is a long season in Iraq. Research tackles problem decreasing in supplying electric power and the disability of government in providing sufficient electric power to the citizens. The research discusses the possibility of decrease of electric power consumption through the study of the orientation factor in the urban planning of a town sector of 4869 residential buildings. Therefore, the research suggests the possibility of calculation of the cooling loads and electric power consumption of a residential building located on an area of 200m2. The ground floor is 150m2 and the first floor is 100m2. This residential building has been entered into e-Quest program at thermal conditions similar to the weather conditions of Basra province and the results show that the best orientation in decreasing the annual electric consumption are the north and south directions. Research hypothesis the possibility of rotation all residential buildings of Yassin Khuraibet town to the north and south, and these directions are depended according to practical study as above. Research methodology Yassin Khuraibet is a case study. There is an attempt to re-design the city with preserving the number of the residential buildings, parks and services of this town and to study the effect of residential building orientation to the north and south that are the best directions of electric power consumption for cooling purposes. Research results appear after it is oriented all residential buildings to the north and south, the town is acceptable in terms of urban planning. The result of calculation shows the decrease of cooling loads 8% and electric power consumption 11%.