Application and Comparison of Exergetic Cost Theory and Wonergy Methods to a Biogas Engine Powered Cogeneration
This study presents the application and comparison of the two exergoeconomic cost accounting methodologies, exergetic cost theory and wonergy methods, to a simple biogas engine powered cogeneration system. Exergetic cost theory is one of the most remarkable exergoeconomic methods, based on a solid mathematical background; in this respect, it is one of the leading approaches in the field of thermoeconomic. In this method, exergetic cost of the inner flows are determined with the help of an incidence matrix. This matrix shows the inlet and outlets of the subcomponents of the system. By implementing the exergetic costs to known initial investment costs and operating and maintaining costs as well as other system economic data, exergy based costs of all flows and components are calculated.
Wonergy method takes its name from the worth of energy. This approach is simply based on the division of the system in three parts: work producing and/or consuming components, heat producing and/or consuming components and both heat and work producing and/or consuming components. With this way, for each flow, the time consuming calculations may be eliminated. Exergoeconomic costs can be determined by defining three wonergetic constants for each component in the system. Although these two methodological approaches have their own and different implementation principles, their common points are, in essence, to combine exergy and economic principles. In this study, the application of these two methods to a cogeneration system will be presented and the results obtained will be discussed within the framework of thermoeconomic system parameters.
Derya HAYDARGİL – She received her BSc and MSc degrees in Physics Engineering from Gaziantep University, Gaziantep in 2002 and 2005, respectively. She has completed PhD graduate courses at Mechanical Engineering Department of Gaziantep University and continues to study on her thesis.