An important feature of heat exchanger network design is the energy-capital tradeoff. This tradeoff has been regarded as complex due to the number of structural network alternatives usually available, each being subject to continuous optimization. Current procedures tend to first identify minimum energy networks. The total cost (capital and energy) can then be improved by evolution and continuo...

The paper discusses optimal operation of a general heat exchanger network with given structure, heat exchanger areas and stream data including predefined disturbances. A method that combines the use of steady state optimization and decentralized feedback control is proposed. A general steady state model is developed, which is easily adapted to any heat exchanger network. Using this model period...

This work deals with membrane separation processes, their modelling and optimal control. A self-optimizing control is introduced, a method proposed by Johannes Jäschke (NTNU, Norway) to control heat exchanger network by controlling "Jäschke temperatures". This type of self-optimizing control is applied to control membrane processes, specifically membrane contactor network. This network consists...

A cDNA clone encoding a rabbit ileal villus cell Na+/H+ exchanger was isolated and its complete nucleotide sequence was determined. The cDNA is 4 kb long and contains 322 bp of 5'-untranslated region, 2451 bp of open reading frame and 1163 bp of 3'-untranslated area, with 70%, 91% and 40% identity to the human sequence, respectively. Amino acid sequence deduced from the longest open reading fra...

To evaluate the influence of the sodium/proton exchanger (Na+,H+ exchanger) on the constriction of rat resistance vessels and on the iliac artery, the isometric vasoconstrictions of renal resistance vessels and strips from iliac artery derived from Wistar-Kyoto rats were measured using a vessel myograph. The Na+,H+ exchanger was activated by intracellular acidification using propionic acid. Cyt...

This paper presents a flexible HEN (heat exchanger network) synthesis methodology for designing multiperiod with streams involving phase changes. The is based on an MINLP (mixed integer nonlinear programming) model, identification of critical points, and flexibility index analysis considering A nominal topology constructed in the first step. Then each process operating condition’s points are ca...

The main objective of this study is to predict air temperature and humidity at the outlet of a wire-on-tube type heat exchanger using neural networks. For this purpose, initially the heat exchanger was coupled to a refrigeration unit and placed in a wind tunnel. Afterwards, its performance was tested under various experimental conditions. We measured nine input parameters, namely, temperature a...