an investigation on the thermal performance of the soil as geothermal heat energy storage medium has been conducted. the thermal characteristics of the soil storage and the heat transfer from a heat exchanger in the soil, surrounding and bottom surface will be discussed. this investigation forms a contribution to a project to realize such storage to be charged from a solar heating system. this ...

The design or scale-up of heat transfer systems in fluidized beds require estimation of the effective heat transfer coefficient on heat transfer surfaces in contact with the fluidized medium. In this study, the effects of operational parameters on bed-to-wall heat transfer in CFBs is investigated such as solids volume fraction, particle diameter, suspension density, superficial velocity and sol...

The potential of nanofluids for the improvement of heat transfer coefficient in various heat exchangeequipment has been considered and studied as a major application during recent decades. In this research,heat transfer coefficient of ZnO, TiO2 and ZnO/TiO2 nanofluids in a shell and tube heat exchanger has beenstudied experimentally. ZnO nanoparticle was synthesized through pre...

The single-phase flow and thermal performance of a double pipe heat exchanger are examined by experimental methods. The working fluid is water at atmospheric pressure. Temperature measurements at the inlet and outlet of the two streams and also at an intermediate point half way between the inlet and outlet is made, using copper-constantan thermocouple wires. Mass flow rates for each stream are ...

This paper presents the fabrication and application of a micro-scale hybrid wicking structure in a flat polymer-based heat pipe heat spreader, which improves the heat transfer performance under high adverse acceleration. The hybrid wicking structure which enhances evaporation and condensation heat transfer under adverse acceleration consists of 100 μm high, 200 μm wide square electroplated copp...

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...

natural convection heat transfer from a tube bundle in the indirect water bath heaters is investigated. a computer-code is used for the solution of the governing equations of mass, momentum and energy transfer based on the simple-c algorithm. simulations are carried out for the gas pressure station heater of kermanshah city with various tube bundle arrangements. in order to validate the numeric...

The success of innovative fouling mitigation techniques such as ion implantation depends upon early stage of scale formation on heat transfer surface. This is because the first crystalline nuclei that appear on the surface during the initial period dictate how fouling would develop in latter stages. In this study, the initial period of deposition of calcium sulphate on heat transfer surfaces ha...

Performance enhancement of the two-phase flow boiling heat transfer process in microchannels through implementation of surface micro- and nanostructures has gained substantial interest in recent years. However, the reported results range widely from a decline to improvements in performance depending on the test conditions and fluid properties, without a consensus on the physical mechanisms resp...

an analytical study was performed to study effects of thermo-diffusion and chemical reactions on a three-dimensional mhd mixed convective flow of dissipative fluid along an infinite vertical porous plate with transverse sinusoidal suction velocity. the parabolic partial differential equations governing the fluid flow, heat transfer, and mass transfer were solved using perturbation technique and...