فهرست مطالب khalil mojaveryagah

Steam power plants are an advanced and complex design of the Rankin steam-liquid cycle. Therefore, understanding the concepts of effective parameters in increasing energy and exergy efficiency and also exergoeconomic are very important. The purpose of this study is to investigate the three basic scenarios of steam power plants, till the required changes in design and its effects on power plant efficiency to be determined. The third scenario has a preheater, a deaerator and two turbine extraction. The second scenario has a turbine extraction and preheater. In third scenario, energy and exergy efficiency are 20.74% and 26.91%, respectively. it’s increases of energy and exergy efficiency relative to second scenario are equal to 19.13% and 9.48%, respectively. Exergoeconomic analysis has shown that boiler and turbine have the highest total cost of investment, maintenance and exergy destruction, hence special attention should be paid to this equipment. The high relative cost factor of the boiler (r) indicates that the boiler efficiency can provide an overall improvement in the cost of this equipment. This can be done by reducing the exergy destruction by preheating and reducing losses and use of excess air. The Exergoeconomic coefficient of fk turbine is high. This means that to reduce the cost of the turbine, the possibility of reducing parameters such as inlet steam temperature, turbine pressure and it’s efficiency should be given more attention.

Nowadays, so much heat has been generated in data centers which is caused by many electronic devices. This generated heat has been increased proportionally with the number of racks in IT rooms .In other hands, the power consumption of IT cooling system is more than 43% of total electrical consumption in data centers, hence the technology of its cooling systems is very important. Selection of cooling system design should provide the most efficiency and the least power consumption. In this paper, data centers with raised floor or without raised floor will be considered and 9 air distribution procedures for air cooling of IT rooms will be discussed and will be compared. According to the number of IT’s racks and power consumption of IT’s cabinets, the best selection of air distribution options will be determined .by the results of this paper , the clients of data centers could choose the best cooling system options which are appropriate with the number of racks and the power heat generation in data centers.