The thermal performance of a heat exchanger is important for the potential application in an integrated solar cell/module and thermoelectric generator (TEG) system. Usually, the thermal performance of a heat exchanger for TEGs is analysed by using 1D heat conduction theory which ignores the detailed phenomena associated with thermo-hydraulics. In this paper, thermal and momentum transports in t...

A numerical and experimental investigation of flow and heat transfer in a gas- liquid Thermosyphon Heat Exchanger "THE" with built in heat pipes and aluminum plate fins for moderate Reynolds numbers has been carried out. It's module is composed of 6 rows and 15 columns copper pipes with aluminum plate fins with dimensions of 130cm height, 47cm width and  20cm depth. The tubes have been fill...

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...

BACKGROUND During mechanical ventilation effective conditioning of inspired air is important. In this respect, conventional humidifiers do not perform optimally. By design, a counter-flow-type humidifier should improve humidification and heating, but may increase resistance. METHODS We investigated mechanical impedance and work of breathing (using pressure-flow characteristics and additional ...

In the present work, the performances of improved two-stage multi inter-cooler trans- critical carbon dioxide (CO2) refrigeration cycles with ejector and internal heat exchanger have been examined. In the new improved cycles, an internal heat exchanger is append to the cycles. Also, second inter-cooler in improved cycles, cooled with the refrigeration of the cycle, so that in first c...

Enhancement of heat transfers in counterflow plate heat exchanger due to presence of an intermediate auxiliary fluid flow is investigated. The intermediate auxiliary channel is supported by transverse conducting pins. The momentum and energy equations for the primary fluids are solved numerically and validated against a derived approximate analytical solution. A parametric study including the e...

Heat transfer coefficient and thermal efficiency of γ-Al2O3/water nanofluids flowing through a double tube heat exchanger were experimentally investigated. The nanoparticles were well dispersed in distilled water at 0.05–0.15 %vol. A large number of experiments were performed at different fluid flow rates under turbulent flow regime (18,000<Re<40,000) and various nanofluid...

This study numerically investigates a double pipe heat exchanger with triangle and rectangle rib. The simulation is performed using ANSYS package, considering turbulent flow k-e turbulence model. working fluid water in both tube annulus the arrangement counter flow. results show that, transfer of rib are higher than that normal DPHE as Reynolds number increasing transfer, coefficient transfers ...

An experimental study of heat transfer characteristics with and without insert was found using water –water system on 1-2 pass shell and tube heat exchanger. Experimental results such as exchanger effectiveness, overall heat transfer coefficient were calculated using with and without insert. There is improvement in overall heat coefficient, efficiency in using twisted tape. In all the process i...