1. The anatomy of the counter-current heat exchanger of skipjack tuna is described and the pattern of blood flow is analysed. 2. The pattern of blood flow is from the dorsal aorta, through the exchanger to segmental arteries to the tissues, from the tissues to segmental veins and back through the exchanger to the post-cardinal vein. 3. The vessels in the exchanger are about the same size as sys...

The objective of this paper is to evaluate and optimize the performance of 1 kW integrated heat exchanger module for new generations of air cooled heat exchangers. The first objective is to minimize the ratio of the header frontal area to the entire heat exchanger frontal which will help to reduce the header size. The second objective is to minimize the pressure drop for the entire heat exchang...

In industrial environments, the heat exchanger is a necessary component to any strategy of energy conversion. Much of thermal energy used in industrial processes passes at least one times by a heat exchanger, and methods systems recovering thermal energy. This survey paper tries to presents in a systemic way an sample control of a heat exchanger by comparison between three controllers LQR (line...

one way to increase the heat transfer is to use perforated twisted tapes with different hole diameters, which largely improve heat transfer with an increase in the heat transfer area at the constant volume and more mixed flow. in the previous studies, the effect of nanofluids with perforated twisted tapes is less studied. in this work, the performance of water / iron oxide nanofluid in a double...

Temperature of fluid stream through tube is a key variable in shell and tube heat exchanger. However, this variable is not easy to measure straightly. Therefore, a state observer is designed to estimate the tube temperature variable for direct control of shell and tube heat exchanger. A dynamical state space model is used to describe the heat exchanger process. Kalman filter based observer is d...

Abstract—Liquid spray heat exchanger is the critical equipment of temperature regulating system by gaseous nitrogen which realizes the environment temperature in the range of -180 °C~+180 °C. Liquid nitrogen is atomized into smaller liquid drops through liquid nitrogen sprayer and then contacts with gaseous nitrogen to be cooled. By adjusting the pressure of liquid nitrogen and gaseous nitrogen...

In this paper, a rigorous MILP formulation for grass-root design of heat exchanger networks is developed. The methodology does not rely on traditional supertargeting followed by network design steps typical of the Pinch Design Method, nor is a non-linear model based on superstructures, but rather gives cost-optimal solutions in one step. Unlike most models, it considers splitting, non-isotherma...

A Sequential Framework for Heat Exchanger Network Synthesis (HENS) is presented. The network generation and optimization phase of the framework, one of its core subproblems, is presented with details as to the source of the non-convexities in the model. Physical insight based automated starting value generators are developed to ensure that the base NLP formulation solves to a ‘good’ local optim...

0017-9310/$ see front matter 2010 Elsevier Ltd. A doi:10.1016/j.ijheatmasstransfer.2010.09.029 ⇑ Corresponding author. Tel.: +1 765 494 5705; fax E-mail address: [email protected] (I. Mud This study explores the use of a high-pressure metal hydride (HPMH), Ti1.1CrMn, to store hydrogen at high pressures (up to 310 bar) and temperatures below 60 C, conditions that are suitable for automobile...

The design of heat exchanger networks (HEN) is a well-studied problem in process synthesis and an ideal test base to benchmark methods and techniques in the field. Despite a significant number of relevant publications, networks are still designed under assumptions of fixed operating conditions. Significant variations in supply and demand, alongside a need for efficient management in energy mark...