Thermoeconomics

HEAT STORAGE BY PHASE CHANGING MATERIALS AND THERMOECONOMICS... 

Keywords Latent heat storage exergy analysis, thermoeconomics, economic analysis... 

Combined principles of thermodynamics are widely utilized in assessing the performances of heat storage systems. Thermoeconomics further combines the thermodynamic principles with engineering economics to estimate the cost of exergy, and optimize the cost under various constraints. Although, Valero et al. (1989) tried to unify the thermoeconomic theories, the concepts and procedures may vary, and create ambiguity in practical applications (Szargut, 1990 Tsataronis, 1993 Erlach et al., 1999 Sciubba, 2003). 

Structural theory facilitates the evaluation of exergy cost and incorporation of thermoeconomics functional analysis (Erlach et al., 1999). It is a common formulation for the various thermoeconomic methods providing the costing equations from a set of modeling equations for the components of a system. The structural theory needs a productive structure displaying how the resource... 

Thermoeconomics of LHS systems involve the use of principles from thermodynamics and fluid mechanics and heat transfer. Therefore, thermoeconomics may be applied to both the use of those principles and materials, construction, and mechanical design, and a part of conventional economic analysis. The distinguished side of it comes from the ability to account the quality of energy and environmental impact of energy usage in economic considerations. 

Thermoeconomics of the LHS system involves fixed capital investment, operational and maintenance cost, and exergy costs (Domanski and Fellah, 1998). Total fixed capital investment consists of (i) direct expenses that are equipment cost, materials, and labor, (ii) indirect project expenses that are freight, insurance, taxes, construction, overhead, (iii) contingency and contractor fee, and (iv) auxiliary facilities, such as site development, auxiliary buildings. 

This analysis considers the three basic components of a seasonal LHS system (Figure 25) constructed after one year. Table 7 shows the data used in thermoeconomic analysis. 

TABLE 7. A typical data used for thermoeconomic analysis of seasonal heat storage system... 

Domanski, R., and Fellah, G., 1998, Thermoeconomic analysis of sensible heat, thermal energy storage systems, Applied Thermal Eng. 18 693—704. 

Durmayaz, A. Sogut, S. Sahin, B., and Yavuz, H., 2004, Optimization of thermal systems based on finite-time thermodynamics and thermoeconomics, Progress in Energy and Comb. Sci. 30 175-217. 

Erlach, B., Serra, L., and Valero, A., 1999, Structural theory as standard for thermoeconomics, Energy Conversion Mgmt. 40 1627—1649. 

Gonzalez, A. Sala, J.M., Flores, I., and Lopez, L.M., 2003, Application of thermoeconomics to the allocation of environmental loads in the life cycle assessment of cogeneration plants, Energy 28 557—574. 

Szargut, I, 1990, In Finite-Time Thermodynamics and Thermoeconomics, eds. By S. Sieniut-cyz, P. Salamon, Taylor Francis, New York. 

Tsataronis, G., 1993, Thermoeconomic analysis and optimization of energy systems, Progess Energy Comb. Sys. 19 227—257. 

Valero, A., Correas, L., Zaleta, A., Lazzaretto, A., Verda, V, Reini, M., and Rangel, V, 2004a, On the thermoeconomic approach to the diagnosis of energy system malfunctions Part 1 the TADEUS problem, Energy 29 1875—1887. 

Coming, P.A. (2002). Thermoeconomics beyond the second law. J. Bioeconom., 4, 57-88 Everett, D.H. (1959). An Introduction to Chemical Thermodynamics. Longmans, London Kinosita, K., Yasuda, R., Noji, H. and Adachi, K. (2000). A rotary molecular motor that can work at near 100% efficiency. Philos. Trans. Act. Royal Soc. London B, 355, 473—489. See also Proc. Biochem. Soc. (2005) Meeting Mechanics of Bioenergetic Membrane Proteins Structures and... 

Chen, J. and Wu, C., Thermoeconomic analysis on the performance characteristics of a multi-stage irreversible combined heat pump system. ASME Journal of Energy Resources Technology, 122(4), 212-216, 2000. 

S. Sieniutycz and P. Salamon, Eds., Finite Time Thermodynamics and Thermoeconomics, Advances in Thermodynamics, Vol. 4, Taylor and Francis, 1991. 

The resultis given inFigure 13.7 for an assumed ratio of T0/T, = 0.5, that is, an ordinary power station. For a renewable fuel / is close to 0 and the optimal efficiency is 0.3 as opposed to the Carnot value of 0.5. For a costly nonrenewable fuel such as natural gas with/ = 0.5 (i.e., 50% of all costs are spent on fuel), the optimal efficiency is 0.35, so around 15% better, although possible environmental costs related to the emission of waste have been ignored (although we should not exclude environmental costs for renewable fuel beforehand). Figure 13.8 depicts how the situation improves when Tu the temperature of the heat source, increases. Nevertheless, the trend that nonrenewable fuels are more favorable appears to persist, however, under the same restriction as just mentioned. By the way, this optimum, which we call the economic optimum, is also known as the thermoeconomic optimum and the analysis with which it was obtained is known as thermoeconomic analysis. 

Maikov, V.P., Vilkov, G.G. and Gallstov, A.V., "Optimum Design of Multicolumn Fractionating Plants from the Thermoeconomic Standpoint," International Chemical Engineering Vol. 12,... 

Benedict applied exergy costing to the design of an air separation plant in 1949 see (58). Gaggioli used the methods for the optimal selection of steam piping and its accompanying insulation (50, 59). Evans, Tribus, El-Sayed and co-workers (53, 54) have developed the fundamentals of the subject, under the title of Thermoeconomics, and present chapters in this volume. 

These applications hardly scratch the surface of the potential of exergy costing. Thermoeconomics is only in its infancy. 

Thermoeconomics needs to flourish in order to avoid misconceptions and erroneous statistics which would lead to bad mistakes by engineers involved in design and operating decisions, and by managers and politicians who are involved with "energy" use and development in the private and government sectors. Thermoeconomics needs to flourish not only to avoid bad decisions, but also in order to make good decisions — optimally. 

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