An analytical model for the heat exchanger network (HEN) has been proposed in this work to study dynamic performance of HEN design stage. The relies on Laplace transform obtain system outlet temperature function when facing operational changeover. Equipped with decomposition strategy and pathway analysis, can reach time domain an easy way free numerical difficulty concern caused by inverse proc...

debottlenecking of heat exchanger networks is a very important issue, when a plant is subject to process changes and/or increased throughput. in previous paper, a new targetting method was introduced, that allowed the designer to consider hydrodynamic constraints when debottlenecking a network. in this paper, a design procedure, which guarantees the consistency of the results of targetting stag...

We investigated whether highly purified preparations of basal (fetal-facing) membrane isolated from normal term human placentas possess Na(+)-H+ exchanger activity. Uptake of Na+ into basal membrane vesicles was stimulated many-fold by an outwardly directed H+ gradient. This H(+)-gradient-dependent uptake was inhibitable by amiloride and its analogues. Na+ uptake in these vesicles did not occur...

This paper describes the implementation of a meta-heuristic optimization approach, Tabu Search (TS), for Heat Exchanger Networks (HEN) synthesis and compares this approach to others presented in the literature. TS is a stochastic optimization approach that makes use of adaptive memory in the form of tabu lists. Both recency-based and frequency-based tabu lists are used to provide short-term and...

Heat exchanger networks present an interesting control problem due to coupling among process streams. In this work, the linear quadratic regulator (LQR), a feedback optimal control technique, is used to control stream temperatures on a laboratory scale heat exchanger network, through bypass manipulation, in a multivariable system. The LQR design was based on a mathematical model of the plant an...

This paper presents a new approach to heat exchanger network (HEN) design making extensive use of randomization techniques. It is exceedingly simple to implement and gives new insight into the hardness and the cost landscape underlying a given problem. At the same time, the results from our algorithm may be used as good initial solutions required by most non-linear optimization problem formulat...

Calcium ions play a critical role in neurotransmitter release. The cytosolic Ca2+ concentration ([Ca2+]cyt) at nerve terminals must therefore be carefully controlled. Several different mechanisms, including a plasmalemmal Na/Ca exchanger, are involved in regulating [Ca2+]cyt. We employed immunofluorescence microscopy with polyclonal antiserum raised against dog cardiac sarcolemmal Na/Ca exchang...

A shell and tube heat exchanger is a class of heat exchanger designs seen most common type of heat exchanger in oil refineries and other large chemical processes, and is suited for higher-pressure applications. As its name implies, this type of heat exchanger consists of a shell (a large pressure vessel) with a bundle of tubes inside it. One fluid runs through the tubes, and another fluid flows...

A new methodology is proposed to use comprehensive up-to-date commercial software tools for Heat Exchanger Network (HEN) reliability modelling and optimisation. The idea behind this proposal that apply the combination of specific HEN optimisation packages has several advantages over commonly used approach. There a variety features need be taken into account choose right tool. design significant...

The deterioration of the performance of a cross flow heat exchanger with condensation due to the longitudinal conduction was investigated. For a relatively small change of wall temperature along the flow directions which was shown to be common in many applications, the energy equations were solved numerically. An iterative method was used to solve the resulting equations of the finite differenc...