Globally optimal synthesis of heat exchanger networks. Part III: Non‐isothermal mixing in minimal and non‐minimal networks

Abstract

In this work, the enumeration algorithms presented in Parts I and II for the globally optimal synthesis of minimal and non‐minimal heat exchanger networks are extended to consider non‐isothermal mixing. New mathematical models, including non‐isothermal mixing constraints, are proposed to target the bounds of energy consumption and the binding exchanger minimum approximation temperature. These models are solved using the algorithms, which involve solving systems of equations instead of mathematical programming. Three global optimization strategies are proposed to optimize each enumerated structure, involving the use of a global solver directly, or the use of a Golden Search based on energy consumption and a flowrate optimization model considering non‐isothermal mixing. The flowrate optimization model is reformulated as a convex problem, which is solved by using nonlinear programming or a mathematical programming‐free methodology, that is, solving Karush–Kuhn–Tucker equations. A new Global Optimum Search Algorithm is developed and examples are tested comparing different optimization strategies.

A Tabu-Matching Heuristic Algorithm Based on Temperature Feasibility for Efficient Synthesis of Heat Exchanger Networks

“…Comparing the proposed methodology to the original NSM-RWCE algorithm, it is found that the former leads to an annual savings of USD 5430. Moreover, it outperforms the literature findings [45] by 0.80%. C7 spanning one temperature interval are assigned three nodes thereon, the streams H4, H5, C2, and C4 spanning two temperature intervals are posted with six nodes, and nine nodes are given to the stream C1 spanning three temperature level intervals, as shown in Figure 14.…”

“…Comparing the proposed methodology to the original NSM-RWCE algorithm, it is found that the former leads to an annual savings of USD 5430. Moreover, it outperforms the literature findings [45] by 0.80%.…”

“…Caballero et al [44] proposed a sequential approach combining the TransHEN and the HENDesign model, obtaining a TAC of USD 1,414,831/yr. Chang et al [45] developed a global optimum search algorithm with a TAC of USD 1,407,203/yr.…”

Globally optimal simultaneous heat exchanger network synthesis and basic heat exchanger design

“…We show in this article that some problems require considering multiple shell arrangements due to temperature cross when more than one pass is considered. This article proposes a new approach focusing on the network enumeration procedure proposed by Chang et al, [42][43][44] which is used together with the Set Trimming approach used by Lemos et al 45 for the design of HEXs. The design model guarantees global optimality and is coupled to the synthesis procedure in a way that also renders global optimality.…”

Global optimization of the design of intensified shell and tube heat exchanger using tube inserts

“…[1] Therefore, it is of great importance to design the optimal STHE to enhance heat transfer performance, [2,3] decrease device sizes, [4,5] and lower economic costs. [6][7][8] Over the past few decades, significant efforts have been devoted with broad applications to industrial practice, bringing considerable energy saving, [9] economic profit, [10][11][12] and environmental benefits. [13,14] Early attempts to design STHE from the typical book [15] and classical textbook [16] used an effective trialand-error procedure.…”