Journal of Energy, Environment & Carbon Credits Volume 3, Issue 2, ISSN: 2249-8621 __________________________________________________________________________________________ JoEECC (2013) 1-10 © STM Journals 2013. All Rights Reserved Page 1 Energy, Exergy and Exergoeconomic Analysis of a Forced Draft Cooling Tower Shadrach Osokam Onyegu* Department of Mechanical Engineering, Faculty of Engineering, University of Port Harcourt, Port Harcourt, Nigeria Abstract This paper presents the results of energy, exergy and exergoeconomic analysis for a forced draft cooling tower. The work was done using field data from an operating system spanning ten (10) years. The process was modelled mathematically and computer simulations were made using the MS Excel environment, specifically on the dependence of both the energetic efficiency on the inlet water temperature and the second law efficiency on the inlet water temperature, ambient temperature and relative humidity was investigated, and the cost associated with the exergy destroyed, the average cost per unit exergy, ratio of mass flow rates of water and air and the exergoeconomic factor for the cooling tower were simulated. The results from the analysis compare formally with those in the literature; this study demonstrates that exergoeconomic analysis can provide extra vital information than the energy and exergy analysis alone. Keywords: cooling tower, exergy analysis, second-law efficiency, exergoeconomic analysis *Author for Correspondence E-mail: onyeguosokam@gmail.com, INTRODUCTION A cooling tower is a heat rejection device, whose main function is to extract waste heat from warm water and release it to the atmosphere. Cooling towers cool the warm water discharged from the condenser and feed the water back to the condenser. Unlike the car radiator which uses air alone in cooling, cooling towers lower the temperatures of water with the aid of recuperative heat exchangers which is an integral component of a plant resulting to a higher efficiency and cost effectiveness. The technique of exergy analysis has been developed for evaluation of the thermodynamic perfection of systems in terms of exergy and exergy losses. According to Tsatsaronis [1], the monetary basis to which the interaction an energy system experiences with its immediate surroundings and to its associated thermodynamic inefficiencies within a system is attributed to exergy. However, the cost associated with such inefficiency ought to be known, knowledge of costing as applied to energy systems is very vital for improving their cost effectiveness, that is, in reducing the cost of the final product produced by the system [2]. Saravanan et al. [3] considered the effect of inlet air wet bulb temperature and inlet water temperature on the performance of a cooling tower by carrying out energy and exergy analysis of a counter flow wet cooling tower. Thirapong et al. [4] carried out exergetic analysis on the performance of a counter flow cooling tower; in their research, the results obtained show that the drop in efficiency started from the top of the cooling tower and increased downwards as a result of increasing exergy destruction along the cooling tower downwards. It also shows that as a result of irreversibilities, the cooling process perform poorly at the bottom and gradually improve along the height of the tower. Cardona and Piacentino [5] carried out an investigative research on how to optimize the performance of variable demand energy systems by exploring the exergoeconomic approach using aggregate consumption data and case oriented technique which simplifies the flow of exergy between systems. Boumaza et al. [6] carried out thermal performances investigation of a wet cooling tower by carrying out experimental investigations on a