in this paper, overall heat transfer coefficient and friction factor of water based γ-al2o3 nanofluid in a double tube counter flow heat exchanger have been measured experimentally under turbulent flow condition. for better dispersion of γ-al2o3 nanoparticles in distilled water, magnetic stirrer and ultrasonic vibrator (with a power of 240 kw and frequency of 35 khz) were implemented. the stabi...

nanofluid is a new class of heat transfer fluids engineered by dispersing metallic or non-metallic nanoparticles with a typical size of less than 100 nm in the conventional heat transfer fluids.this article aims to investigate the overall and convection heat transfer coefficient and nusselt number of al2o3-water nanofluid flowing in a horizontal double pipe heat exchanger under turbulent flow (...

This article presents the results of the experimental runs of a prototype of R744 (CO2) refrigeration system operating in a both air conditioning and heat pump mode when heat rejection is done in supercritical region. The prototype system is sized for a compact car. Data presented are in the limited range of operation. Further optimization and extension of operating range is underway. Test faci...

In present work, comparison of three different tube bundles for particular heat exchanger is proposed. Three types are smooth, micro finned and corrugated tubes. Heat exchanger will be designed with smooth tube bundle and simulated. Micro fin and corrugation over tube is applied separately for same heat exchanger in feasible size and simulated for performance. Besides, comparison is done with h...

Heat exchangers are one of the most important devices of mechanical systems in modernsociety. Most industrial processes involve the transfer of heat and more often they requirethe heat transfer process to be controlled. A heat exchanger is the heat exchanged betweentwo media, one being cold and the other being hot. There are different types of heatexchanger, but the type which is widely used in...

This two-part study explores the development and thermal performance of a coiled-tube heat exchanger for hydrogen fuel cell storage systems utilizing High-Pressure Metal Hydride (HPMH). The primary purpose of this heat exchanger is to tackle the large amounts of heat released from the exothermic hydriding reaction that occurs when the hydrogen is charged into the storage vessel and is absorbed ...

The reduction of SO2 and PM for marine engines was investigated using the electrostatic precipitator (ESP) with the heat exchanger. The experiments were carried out to reduce SO2 due to condensation of water in the exhausted gas. The experimental system consists of the diesel engine, the heat exchanger and the ESP. The exhausted gas at 180 o C of the temperature is cooled to 20 o C, and generat...

in this paper, a new systematic design methodology has been developed for thes imultaneous energy and water minimization in multiple-contaminant systems that also feature maximum re-use of water. in addition to allowing re-use of water in multiple-contaminant systems, issues about heat losses and flowrate changes inside unit operations have also been incorporated in this new design method. to i...

In a cylindrical scraped heat exchanger crystallizer geometry the flow field influence on the local heat transfer distribution on an evenly cooled scraped heat exchanger surface has been studied by direct measurements of the heat exchanger surface temperature and the fluid velocity field inside the crystallizer. Liquid Crystal Thermometry revealed that the local heat transfer is higher in the m...