Use of genetic algorithms for the optimal design of shell-and-tube heat exchangers

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Design of shell-and-tube heat exchangers using multiobjective optimization

This paper presents a procedure for minimizing the cost of a shell-and-tube heat exchanger based on genetic algorithms (GA). The global cost includes the operating cost (pumping power) and the initial cost expressed in terms of annuities. Eleven design variables associated with shell-and-tube heat exchanger geometries are considered: tube pitch, tube layout patterns, number of tube passes, baffle spacing at the centre, baffle spacing at the inlet and outlet, baffle cut, tube-to-baffle diametrical clearance, shell-to-baffle diametrical clearance, tube bundle outer diameter, shell diameter, and tube outer diameter. Evaluations of the heat exchangers performances are based on an adapted version of the Bell–Delaware method. Pressure drops constraints are included in the procedure. Reliability and maintenance due to fouling are taken into account by restraining the coefficient of increase of surface into a given interval. Two case studies are presented. Results show that the procedure can properly and rapidly identify the optimal design for a specified heat transfer process. Copyright © 2006 John Wiley & Sons, Ltd.

Minimizing shell-and-tube heat exchanger cost with genetic algorithms and considering maintenance

Separation systems mainly involve interfacial mass and heat transfer as well as mixing. Distillation is a major separation system by means of heat supplied from a higher temperature level at the reboiler and rejected in the condenser at a lower temperature level. Therefore, it resembles a heat engine producing a separation work with a rather low efficiency. Lost work (energy) in separation systems is due to irreversible processes of heat, mass transfer, and mixing, and is directly related to entropy production according to the Gouy‐Stodola principle. In many separation systems of absorption, desorption, extraction, and membrane separation, the major irreversibility is the mass transfer process. In the last 30 years or so, thermodynamic analysis had become popular in evaluating the efficiency of separation systems. Thermodynamic analysis emphasizes the use of the second law of thermodynamics beside the first law, and may be applied through (i) the pinch analysis, (ii) the exergy analysis, and (iii...

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Thermodynamic Analysis of Separation Systems

This paper presents a model for estimating the total cost of shell-and-tube heat exchangers (HEs) with condensation in tubes or in the shell, as well as a designing strategy for minimizing this cost. The optimization process is based on a genetic algorithm. The global cost includes the energy cost (i.e. pumping power) and the initial purchase cost of the exchanger. The choice of the best exchanger is based on its annualized total cost. Eleven design variables are optimized. Ten are associated with the HE geometry: tube pitch, tube layout patterns, baffle spacing at the center, baffle spacing at the inlet and outlet, baffle cut, tube-to-baffle diametrical clearance, shell-to-baffle diametrical clearance, tube bundle outer diameter, shell diameter, and tube outer diameter. The last design variable indicates whether the condensing fluid should flow in the tubes or in the shell. Two case studies are presented and the results obtained show that the procedure can rapidly identify the best design for a given heat transfer process between two fluids, one of which is condensing. Copyright © 2008 John Wiley & Sons, Ltd.

Optimal geometry and flow arrangement for minimizing the cost of shell‐and‐tube condensers

An area targeting algorithm for the synthesis of heat exchanger networks

A simple, rapid, and robust algorithm for the design of segmentally baffled shell and tube heat exchangers is presented. The algorithm ensures full use of the maximum allowable pressure drops given typically as design specifications, with no geometric restrictions on the equipment. The core of the algorithm is provided by two compact formulations that relate the pressure drop for each side of the exchanger with the film heat transfer coefficient and the exchanger area. The compact formula for the tube side includes the effects of tube ends while the one for the shell side is based on the Bell-Delaware method. The parameters of the compact formulas are used as search variables in the design algorithm. Two examples are presented that show how the algorithm compares to other reported design methods and how the search for realistic solutions is aided by this method.

Medardo Serna

Papers

An area targeting algorithm for the synthesis of heat exchanger networks

An Efficient Method for the Design of Shell and Tube Heat Exchangers