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Abstract
Subject to temperature disturbance, exchangers in heat exchanger network will interact. It is necessary to evaluate the degree of temperature fluctuation in the network. There is inherently linear relationship between output and inlet temperatures of heat exchanger network. Based on this, the concept of temperature-change sensitivity coefficient was put forward. Quantitative influence of temperature fluctuation in the network was carried out in order to examine transmission character of temperature fluctuation in the system. And the information was obtained for improving the design quality of heat exchanger network. Favorable results were obtained by the introduced method compared with the experimental results. These results will assist engineers to distinguish primary and secondary influencing factors, which can be used in observing and controlling influencing factors accurately.
Keywords
Heat exchanger network, temperature-change sensitivity coefficient, experiment
Date received: 29 March 2015; accepted: 16 July 2015
Academic Editor: Hongwei Wu
(ProQuest: ... denotes formulae omitted.)
Introduction
Heat exchanger network (HEN) synthesis is a means of utilizing the heat available in a process.1 As an integrated process design method, the pinch technology proposed by Linnhoff and Townsend2 has formed the backbone of other methods. Umeda3 has divided the process synthesis into five stages: development, planning, basic design, detailed design, and improvement. The complex problem is how to ensure each stage synthesis is optimum. In order to overcome the above difficulties, predecessors have put forward lots of synthesis methods. Challand et al.4 presented some computer programs based on dual temperature approach method. And these programs help in establishing energy conservation targets. In this method, heat recovery approach temperature (HRAT) is at the pinch point. At the same time, exchanger minimum approach temperature (EMAT) is introduced as a decision variable, and heat transfer through pinch point is allowed. The pseudopinch design method (PPDM) was introduced by Wood et al.,5 which was based on the principle of thermodynamics. This method increased freedom of streams matching comparing with pinch method. Suaysompol and Wood6 presented the flexible pinch design method (FPDM), which used a heuristic procedure. In this method, fixed energy designs could be achieved with relatively simple networks. Based on the above method, a computer-aided design package for HENs was introduced.7 Huang et al.8 proposed a mixed-integer nonlinear programming (MINLP) formulation and a solution...