The present study involves experimental analysis of the modified Closed Wet Cooling Tower (CWCT) based on first and second law of thermodynamics, to gain a deeper knowledge in this important field of engineering in Iraq. For this purpose, a prototype of CWCT optimized by added packing under a heat exchanger was designed, manufactured and tested for cooling capacity of 9 kW. Experiments are conducted to explore the effects of various operational and conformational parameters on the towers thermal performance. In the test section, spray water temperature and both dry bulb temperature and relative humidity of air measured at intermediate points of the heat exchanger and packing. Exergy of water and air were calculated by applying the exergy destruction method on the cooling tower. Experimental results showed a significant performance improvement when using packing on the CWCT. It can be observed that the thermal efficiency for the CWCT with packing under a heat exchanger and CWCT with packing above the heat exchanger are approximately 40% and 25% higher than that of the CWCT without packing respectively. As another part of the experiment results, it is indicated that the exergy destruction is directly proportional to air flow rate, cooling water flow rate, inlet cooling water flow rate and inlet Air Wet Bulb Temperature (AWBT) whereas, it is inversely proportional with spray water flow rate. In comparison with the cooling capacity of the tower, it was found that the exergy destruction approximately less than 20%. Exergy efficiency behavior is inversely proportional with the behavior of the exergy destruction. Empirical correlations are obtained to predict water film heat transfer coefficient and air-water mass transfer coefficient considering the influences of operational parameters.
المؤلف / د. محمود أحمد شاكر غضيب تدريسي في جامعة بغداد / كلية العلوم الإسلامية / قسم اللغة العربية / حاصل على شهادة الدكتوراه عام 2019 في الادب العربي الإسلامي
This search aims to meditate Divan of Hazem Al-Qirtagni his incomplete contiguous and non-contiguous naturalizations are investigated through two interrelated sections, the first is contiguous deficient naturalization and the analysis of phonemic symmetry in the light of syntactic syntax
The early childhood is a dangerous period for the development of children
in their present and future life . It is important to design programs for the preschool
period .
These programs are relatd to the childs Personality and its integration .
The most effective stories and attractive programs for the child is the objective
stories which can develop his self-canfidence . Therefore the kindergarten
should participate in developing the childs personality and experience
because it is the most effective institute in the childs life .
The present study aims at finding out the effect of the narrative program in
the kindergartens . This has been done by investigating the truth of a number
of hypotheses to measure
This paper deals with the most important issue in sustainable demelpment in Arabic Islamic economic ideology.
It discusses the concept of zakat & its developments.It give ahistorical view on Zakat depanding or Holy Quran we identify that zakat depanding or Holy Quran. We identify that Zakat must be: gold, silver &its position inits indgment suchas cashpaper