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.
The Negro minority in the United States is associated with social injustice,
political deprivation, and economic oppresion. Its members felt that they are
second-class citizens, and that the acceptance of such status will lead to the
continual oppresion of the Whites upon them. As a result, the educated community
adopted a process to put a framework to their opposition to the former's injustice.
This organised framework is exemplified in the "Niagara Movement," which is
regarded as the first national organisation for Negros. The topic of this study is
chosen due to its historical and political significance.
The study consists of an introduction and five sections. The first section
addresses the preliminaries an
Barium–doped TiO2 / n-Si photodetector was fabricated by spray pyrolysis exhibited visible enhancement responsivity profile with peak response at 600 nm flat response between 650 and 900 nm. The quantum efficiency was 30% and specific detectivity was 5x1012 W-1Hz1/2cm at peak response. The GaAlAs laser diode was used to estimate the rise time of the detector.
The Subject of contritutions to Jerusalemites Scientific in Egypt from 8.5 Century 14.11 AD of noteworthy studies Concern Coming Of these Scientists to Egypt has helped toth to Seek Knowledge and Study or teaching in the tooming w0rid of Science broadly and distinctive through Scientific interaction and intermingling of Civilization between Scientists this Mixing effect of the Scientific life and in tellectal of The nam
... Show MoreThe Andalusi did not leave any poetic art without expressing his psychological and sentimental emotions and the depth of emotions and it sincerity. We found Andalusian translated his emotions into poetry and in many different subjects
There are many economic and financial visions that were mentioned in the book (Al-Anis Al-Mutreb in Rawd Al-Qirtas in the News of the Kings of Morocco and the History of the City of Fez). As this valuable book includes between its two covers, narrations that reveal important and pioneering events and practices that took place and were applied in the recent past on the scene of the countries of the Maghreb. This prompted the officials in the Marinid state to take quick measures to address and confront what happened. Despite the large number and severity of these repercussions and interactions, it is not the nature of this research to download texts and visions beyond what they can bear, but
... Show Moreعُني العرب منذ القدم بإستعمال الجواهروالأحجار الكريمة ، وإزدادت هذه العناية على مر العصور ، فقد إستعملوا الحلي المتنوعة ، والملابس المطعمة بالجواهر والأحجار الكريمة .
التسليات في البلدان الاسلامية مشاهد حياة الطرب والالات الموسيقية كما يعكسها الفن