Optimal Heat Exchange

It is now interesting to ask Can we obtain the same cooling with better effi-cieney The cooling capacity is unaltered if for the same flow F and initial temperature 7k,in the final temperature 7k,out is the same. As the molar entropy depends only on the temperature, this implies that the entropy flows in and out 

approximate value from the equipartition of forces. Reprinted with permission of Tapir Academic Publishers. 

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Gundersen, T. and Naess, L. (1988). The synthesis of cost optimal heat exchanger networks, an industrial review of the state of the art. Comput. Chem. Eng., 12(6), 503-530. 

Gunderson T and Naess L (1988) The Synthesis of Cost Optimal Heat Exchanger Networks An Industrial Review of the State of the Art, Comp Chem Eng, 12 503. 

For the purposes of planning you are asked to determine the optimal heat exchanger areas for the sequence of three exchangers as shown in Figure P8.41. 

Research on the synthesis of economically optimal heat exchanger networks (HENs) has been performed for over 15 years (Nishida et al., 1981). As a result of this research, two general conclusions have emerged (1) the optimum network generally features minimum or close to minimum utility consumption, and (2) the optimum network generally has a mini-... 

T. K. Pho and L. Lapidus. Topics in computer-aided design Part II. Synthesis of optimal heat exchanger networks by tree searching algorithms. AlChEJ., 19 1182,1973. 

Kobayashi, S., Umeda, T. and Ichikawa, A., "Synthesis of Optimal Heat Exchange Systems—An Approach by the Optimal Assignment Problem in Linear Programming," Chemical Engineering Science, Vol. 26, pp 1367-1380, 1971. 

Pho, T.K. and Lapidus, L., "Topics in Computer-Aided Design Part II. Synthesis of Optimal Heat Exchanger Networks by Tree Search Algorithms," AlChE Journal, Vol. 19, No. 6, pp 1182-1189, November 1973. 

Ponton, J.W. and Donaldson, R.A.B., "A Fast Method for the Synthesis of Optimal Heat Exchanger Networks," Chemical Engineering Science, Vol. 29, pp 2375-2377, 1974. 

Fax, D. H. and Mills, R. R., "Generalized Optimal Heat Exchanger Design", Trans. ASME. April 1957, p 653... 

A few other examples are examined here to illustrate the range of geometries that may exist in optimized heat exchangers for cryocoolers. These examples are for Joule-Thomson cryocoolers, which are easily miniaturized. Table 1 lists the operating conditions and important input parameters for all of... 

In the case of air-content as the unique influencing factor, the air-water two-phase flow exhibits a fine-bubble flowing pattern at air-content less than or equal to 10% a slug-shaped gas pattern at air-content between 10% and 40% and a misty pattern with massive fine water droplets at air-content equal to 80%. The output temperature of the tunnel increases with the increase of the air content, and reaches the maximum value. After the peak value, the temperature drops steeply between air content of 20 0% and turns to drop moderately between 40-80% air contents. The simulated results demonstrate that the water based media with the air content ranging from 10% to 40% has better heat-exchange effect than the flow with air content ranging from 40-80%. And the 20% air-contained water flow has the optimal heat exchanging effect. 

Flowsheet analysis and HEN synthesis problem. A material balance has been completed for a process to manufacture styrene and an ethylbenzene byproduct from reactions involving methanol and toluene. See Figure 10.61 for a block flow diagram of the process with the results of material balance calculations. You are to develop an optimal heat exchanger network for this process. Note that ... 

With the high demand for encapsulated materials in the global market, fluid-bed coaters have become more popular. They are used for encapsulating solid or porous particles with optimal heat exchange [105]. The Hquid coating is sprayed onto the particles and the rapid evaporation helps in the formation of an outer layer on the particles. The thickness and formulations of the coating can be obtained as desired. Different types of fluid-bed coaters include top spray, bottom spray, and tangential spray (Fig. 1.16). 

A system is autonomous if the Hamiltonian is no explicit function of z and t. In autonomous systems the Hamiltonian is constant, that is, independent of z and t. For the optimal heat exchange process (z dependent), and for the optimal... 

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