An important issue in the design of systems using borehole heat exchangers is to find costeffective methods to construct the borehole heat exchanger so that heat can be injected or extracted from the ground without excessive temperature differences between the heat carrier fluid and the surrounding ground. This paper presents an overview of experiences and current activities in this field.

at many circumstances, in heat exchange processes several exchangers were used with different cost laws due to their pressure ratings, materials of construction and exchange3r types. in such circumstances traditional methods of pinch technology can not be led to minimum total annual cost may cause some other disadvantages like more complexity or higher maintenance. in this research work a new a...

the paper studies optimization of shell-and-tube heat exchangers using the particle swarm optimization technique. a total cost function is formulated based on initial and annual operating costs of the heat exchangers. six variables – shell inside diameter, tube diameter, baffle spacing, baffle cut, number of tube passes and tube layouts (triangular or square) – are considered as the design para...

OBJECTIVE During invasive mechanical ventilation, inspired gases must be humidified. We previously showed that high ambient temperature greatly impaired the hygrometric performance of heated wire-heated humidifiers. The aim of this bench and clinical study was to assess the humidification performance of passive and active heat and moisture exchangers (HMEs) and the impact of ambient temperature...

Abstract: In this paper a simplified two-dimensional computational model for studying the entropy generation characteristics of thermoacoustic heat exchangers with plane fins is presented. The model integrates the equations of the standard linear thermoacoustic theory into an energy balance-based numerical calculus scheme. Relevant computation results are the spatial distribution of the time-av...

Small minimum temperature approach, large surface area per volume, high heat transfer efficiency and possibility of handling several streams of multi-stream plate-fin heat exchangers lead to more heat recovery and smaller heat exchanger size. Therefore, plate-fin heat exchangers have been applied extensively in sub-ambient processes. However, one major difficulty in optimising the design of pla...

In this paper the effect of site conditions, which are Altitude, Temperature and Relative Humidity and also Heat Dissipation Capacity are investigated on the optimized design of natural draft dry cooling towers with specific kind of heat exchangers, known as Forgo T60 type. A genetic algorithm program has been developed for optimized design of these cooling towers. Objective function includes b...

Heat and moisture exchangers (HMEs) have been increasingly used for humidification during mechanical ventilation in pediatric patients [1]. However, efficacy of HMEs in the pediatric population has not yet been fully evaluated and there is limited information in the literature regarding the effects of ventilator settings and endotracheal tube (ETT) leakage on the humidification performance of H...