An efficient way to reduce the energy required for conditioning buildings and therefore to reduce CO2 emission is the use of proper thermal insulation in buildings' external walls. This measure requires data from metrological stations that can be used in the optimization of the thermal insulation. The main objectives of this study are to construct thermal climatic zones for Libya and to specify the optimum insulation thickness for external walls for the different zones. This work is comprehensive as the metrological data from all existing 33 weather stations has been collected and used for identifying thermal zones. For the optimization of the construction of external walls, the most commonly used local wall structures are investigated: hollow concrete block, limestone block and hollow brick. In addition, four thermal insulation materials: extruded polystyrene, expanded polystyrene, rock wool and foamed polyurethane are used with every wall type. Optimum insulation thickness, energy savings, energy cost and payback periods were estimated for the 33 locations using life cycle cost analysis. A map is constructed for the thermal zones based on degree-day values for the entire country. The results show that limestone blocks with expanded polystyrene insulation form the optimum wall construction as it provides the minimum total cost for all locations. Depending on the Degree-day values, the optimum insulation thickness varies between 5.4 and 15.3 cm across the country with energy saving varies between 28 and 178 $/m2. Using the optimum thickness, the average CO2 emissions can potentially be reduced by about 85%. Finally, a contour map represents the optimum thickness of expanded polystyrene is presented in this work. arabic 12 English 80
Samah Khlifa Otman Alghoul, (1-2021)

فيما بعد arabic 201 English 0
رجب عبدالله عبدالقادر حكومة, علي الصويعي محمد البوزيدي, عبير المبروك عبدالغفار(6-2017)

This paper presents valuable potential savings from fuel and financial expenses of a steam boiler being studied at Elkhmus power plant, Libya. For this research, a visual basic program was developed and being applied for analyzing the gathered data. Key findings pointed to an acceptable level of savings throughout the entire operations within the studied section of the power plant. The highest level of findings was found to be the increasing of thermal gain along with the total efficiency of the boiler as a result of using the exhaust temperature for heating-up the feed water to the boiler. It was clearly found that the increase of the total efficiency has a direct impact on saving the amount of consumed fuel, and thereby the financial expenses were saved by an average of about 11.6% arabic 16 English 78
Rajab HOKOMA, Nabil M. Muhaisen, Omran Alshogi(1-2014)