Study to Analyze Thermal Performance When Building Envelope Specifications Change on Cooling Load

يهدف البحث الى دراسة تأثير تغير التركيب الانشائي لغلاف المباني المشيدة في مدينه بغداد على الاحمال الحرارية المنتقلة. حيث شملت هذه المتغيرات على تغير نوعيه مواد البناء للجدران والسقوف ونوعيه مواد العزل الحراري المضافة نوعيه مواد التغليف الخارجية والداخلية "نوعيه زجاج الوجهات للمباني، تأثير وجود فجوه هوائية بين الجدران، تغير اتجاه المبنى. توصلت الدراسة الى ان افل اتجاه يحقق اقل حمل تبريد هو الاتجاه الشمالي يليه الشمال الشرقي واعلى حمل يحدث في الاتجاه الغربي، كذلك ان مواد البناء الحالية هي اعلى من المواصفات القياسية الحرارية وعليه يجب استخدام نظام العزل الحراري لتقليل حمل تبريد حيث سيتم توفير نسبه تتراوح من %35الى 85 % من حمل التبريد عند عزل الجدران و32%الى 75% عند عزل السقوف. كذلك بينت الدراسة عند استخدام الكوبوند كماده تغليف أفضل من مواد التغليف التقليدية. كذلك ضرورة استخدام الزجاج المظلل او الماص للحرارة بدل الزجاج العادي واستخدام الفجوة الهوائية بين الجدران لتقليل الحرارة المنتقلة.The research aims to study the impact of structural change makeup for the cover of the buildings in the city of Baghdad on the thermal loads .which included these variables to change the quality of construction materials for walls and ceilings and the quality of thermal insulation material added, the quality of packing material external and internal quality of the glass front of the building, the effect of the presence of air gap   between the walls, change the orientation of buildings. The study found that the best direction to achieve lower pregnancy cooling is the direction of the north and the highest heat load occurs in a westerly direction, and the current building materials are higher than the standard thermal and therefore must use a system of thermal insulation to reduce the carrying cooling, which will be available in the range of 35% to85% of the heat load on insulation in walls and 32% to 75% when isolating ceiling

Experimental implementation of thermal enhancement performance of air heat exchanger’s pipes utilizing unconventional turbulator

Heat exchangers are widely used in industry, however, raising their performance are important for the variety of applications. Consequently, efficiency improvement associated with low production cost is considered in this experimental work. The current study aims to enhance the rate of heat transfer in pipe-type heat exchangers experimentally by using a novel nozzle as a turbulator. The cross-sectional shape of the nozzle is hexagonal, and the diameter ratio DR is equal to 0.5. Constant heat flux was maintained in the vicinity of the section of the test tube, while the working fluid was pumped into the open system at six discrete Reynolds number values ranging from 6000 to 19500. To investigate the effect of distance among the pieces, three turbulators with different numbers were assigned and named as (N=4, 5 and 6). The results indicated an increase of 172 %, 194 % and 216 % of the heat transfer rate for cases 4, 5 and 6 respectively comparing to the benchmark tube. On the other hand, the friction factor values increased remarkably due to the inserting of turbulators by about of 722.9 % for N=4, 823.9 % for N=5 and 886.7 % for N=6 compared to a plain tube case. Moreover, it has been established that with the insertion of 6 pieces two enhancements was observed; heat transfer rate and thermal performance, where, thermal performance of all cases exceeds unity (maximum thermal performance of 1.62 has been obtained by inserting 6 pieces of hexagonal nozzles turbulators). A comparison with another types of vortex generators shows the gap between the turbulator and heated surface offers a solution for problems occurred in the pipes of heat exchanger. The study therefore suggests a wider practical implementation of the turbulator

DEVELOPMENT AND EVALUATION OF DOUBLE SOLAR COLLECTORS INTEGRATED WITH VORTEX POWER GENERATOR

Solar vortex power generation is a promising solar thermal technology for power generation. It operates in a moderate temperature scale to generate vortex updraft air stream

DEVELOPMENT AND EVALUATION OF DOUBLE SOLAR COLLECTORS INTEGRATED WITH VORTEX POWER GENERATOR

Solar vortex power generation is a promising solar thermal technology for power generation. It operates in a moderate temperature scale to generate vortex updraft air stream

Evaluation of Sana’a Wastewater Treatment plant – Problem Analysis and Suggested Results

Sana’a wastewater treatment plant (SWWTP) is designed as activated sludge-extended aeration system. The SWWTP has many problems since commissioned in 2000, in terms of technical, design, operational, administrative and financial. This paper aims at studying and analyzing the problems of the Sana’a Wastewater treatment Plant (SWWTP)from the technical, financial, administrative and legal aspects and to develop proposals for solutions in the short and long term. This research was conducted based on the complementary efforts carried out by the authors as field and desk study through working side by side with the expatriates and consulting companies during the last fifteen years since the SWWTP commissioned, in order to support the SWSLC in the operation, maintenance and upgrading of the staff in O&M of the SWWTP due to its complexity as electromechanical technology that needs multidisciplinary specializations. This research was conducted through the operation of the SWWTP and water quality monitoring of influent and effluent of its operating equipment, from which the problems were identified and accordingly the possible solutions were suggested to mitigate these problems, including analyzing the number and level of the available staff and conclude gap in required staff. This study concluded the main problems causing the failure of the SWWTP as follows: Unsuccessful selection of the treatment technology which did not consider the lack in financial and human resources capacity in Yemen, including labor and spare parts; The operational problems experienced by the SWWTP, as increasing operational organic concentrations (BODin = 1160mg /L, BODout =291g/L), compared to the design values (BODin = 500mg /L) (BODout = 30mg /L), which resulted in reaching over the capacity, that resulted in low efficiency (65-70%). This also resulted into deteriorating the effluent and sludge quality and therefore, not possible to sell treated water and sludge to the farmers, which would cover part of the financial budget for O&M of the SWWTP; misuse of the sewerage network by the users through dumping of solid waste, which contributed to the breakdown of the various mechanical units; continue to connect new areas to the network; the difficulty to acquire the land for the implementation of the planned new WWTP, considering the current SWWTP is overloaded; Not applying the organizational structure suggested by the consultant, which resulted in overlap of tasks, which negatively affected the operation of the WWTP; Lack of encouraging and attracting qualified staff and motivating them to stay in the SWWTP by means of providing them with enough salaries and safety tools; Stop completing the implementation of upgrading units, due to the political unrest in Yemen since 2011