Thermodynamic optimization

Lim, J.S., Bejan, A., and Kim, J.H., 1992, Thermodynamic optimization of phase change energy storage using two or more materials, ASME J. Energy Res. Technol. 114 84—90. 

Petlyuk FB, Platonov VM and Slavinskii DM (1965) Thermodynamically Optimal Method for Separating Multicomponent Mixtures, Ini Chem Eng, 5 555. 

Ikegami, Y. and A. Bejan. On the Thermodynamic Optimization of Power Plants with Heat Transfer and Fluid Flow Irrreversibilities. J Solar Energy Engr 120 (2) 139-144 (1998). 

As for many other materials, phase diagrams are roadmaps not only for the description of these substances and of their reactions, but also for their processing and for research and development planning. The systematic experimental determination of phase diagrams, their assessment and compilation and their thermodynamic optimization and calculation are the essential steps in the development of materials science and make up one of the bases of the intermetallic disciplines. 

Calculation, thermodynamic optimization of phase diagrams. The knowledge of phase equilibria, phase stability, phase transformations is an important reference point in the description and understanding of the fundamental properties of the alloys and of their possible technological applications. This interest has promoted a multi-disciplinary and multi-national effort dedicated not only to experimental methods, but also to techniques of optimization, calculation and prediction of... 

A. De Vos, Endoreversible Thermodynamics of Solar Energy Conversion, Oxford University Press, Oxford, 1992 R. S. Berry, V. A. Kazakov, S. Sieniutycz, Z. Szwast, and A. M. Tsvihn, Thermodynamic Optimization of Finite-Time Processes, John Wiley Sons, Chichester, 2000) P. Salamon, J. D. Nulton, G. Siragusa, T. R. Andersen, and A. Limon, Energy 26, 307 (2001). 

B. Andresen. Minimizing losses—tools of finite-time thermodynamics. In A. Bejan and E. Mamut (eds). Thermodynamic Optimization of Complex Energy Systems (Springer, New York, 1999), p. 411. 

Today s polymer industry, however, is mainly driven by economy of scale. High- pressure production units with a capacity up to 500,000 tonnes of polymer a year are being built. Thermodynamic optimization of such processes has led to significant cost savings. 

Bejan A. (1996) Entropy Generation Minimization. The Method of Thermodynamic Optimization of Finite-Size Systems and Finite-Time Processes, CRC Press, Boca Raton, FL. 

Petlyuk FB, Platonov VM, Slavinskii DM. Thermodynamically optimal method for separating multicomponent mixtures. Int Chem Eng 1965 5 555. 

In addition to this thermotropic mesomorphism, a lysotropic mesomorphism is observed [98]. The phase transition temperature, Tt, for the transition from the crystalline to the liquid crystalline state decreases as a function of water content. The decrease in Ttis due to destabilization of the crystal lattice in the head group region by water molecules. This, in turn, decreases the interaction between the fatty acid chains. When the water content reaches a certain level, the phospholipids assume a thermodynamically optimal arrangements whereby the fatty acids are directed to the... 

Petlyuk, F.B., Platonov, V.M. and Slavinski, D.M., "Thermodynamically Optimal Method for Separating Multi component Mixtures," International Chemical Engineering, Vol. 5, No. 3, pp 555-561, July 1965. 

Using the velocity and temperature gradients, we obtain the dimensionless entropy production for the empty bed (Figure 4.10). Comparison of Figures 4.9 and 4.10 indicates that outside the wall region, the distribution of the rate of entropy production is uniform in the packed bed, which is the thermodynamic optimality criterion. The profile of entropy production shows a typical S shape in the empty bed. 

The theory treating near-equilibrium phenomena is called the linear nonequilibrium thermodynamics. It is based on the local equilibrium assumption in the system and phenomenological equations that linearly relate forces and flows of the processes of interest. Application of classical thermodynamics to nonequilibrium systems is valid for systems not too far from equilibrium. This condition does not prove excessively restrictive as many systems and phenomena can be found within the vicinity of equilibrium. Therefore equations for property changes between equilibrium states, such as the Gibbs relationship, can be utilized to express the entropy generation in nonequilibrium systems in terms of variables that are used in the transport and rate processes. The second law analysis determines the thermodynamic optimality of a physical process by determining the rate of entropy generation due to the irreversible process in the system for a required task. 

The new assessment for the Si-C system was primarily based on experimental SiC solubility data in liquid solution given by Scace and Slack [34], Hall [35], Iguchi [36], Kleykamp and Schumacher [37], Oden and McCune [38], and Ottem [14], Solid solubility data given by Nozaki et al. [39], Bean [40], and Newman [41] were used to determine the properties of solid solution. The eutectic composition reported by Nozaki et al. [39] and Hall [35] and peritec-tic transformation temperature determined by Scace [34] and Kleykamp [37] were also used in the thermodynamic optimization. Thermodynamic description of the SiC compound was taken from an early assessment [42]. The... 

Calculations of the Si-C system were presented by Kaufinan (1979) [113] and Olesinski and Abbaschian (1984) [88]. Lim and Lukas (1996) [36] published a thermodynamically optimized dataset which was refined by Grobner (1996) [35]. This dataset is accepted by the present evaluators. The accompanying calculated phase diagram is shown in Fig. 3. SiC decomposes to graphite and carbon-rich liquid silicon at a temperature of 3095 K. 

A thermodynamic optimization of the system was performed by Domer (1982) [167]. This dataset was later refined by Lim and Lukas (1996) [36]. Due to additional crystallographic information concerning the extended homogeneity range of the boron carbide phase [152, 168] a further assessment was necessary [33, 34,169]. Data for the calculated invariant reactions are given in Table 13. Boron carbide of composition 16.4 at.% C melts congruently at 2731 K. 

Fig. 2.3.2-24 General separation scheme for splitting a four-component mixture (a) and development of a thermodynamically optimal separation scheme (a ) [Kaibel 1989a],...

The objective of a thermodynamic optimization is to minimize the inefficiencies, whereas the objective of a thermoeconomic optimization is to estimate the cost-optimal values of the thermodynamic inefficiencies. 

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