Mohammad Ali AkhavanBehabadi

Center of Excellence in Design and Optimization of Energy Systems, School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran

[ 1 ] - Comparative study between dynamic transient and degree-hours methods to estimate heating and cooling loads of building’s wall

In this paper, dynamic transient method and conventional degree-hours method (static) have been compared to estimate heating and cooling loads of building’s wall. All main wall surfaces of various orientations, i.e.South, West, East, North, and horizontal are considered in the climate of Tehran, Iran. In this study, a conventional wall structure, which is comprisedconcrete as main wall material...

[ 2 ] - ارزیابی عملکرد نوارهای پیچیده شده درافزایش انتقال حرارت چگالشی و تأثیر آن برمیزان افت فشار

دراین تحقیق به بررسی افزایش انتقال حرارت توسط نوارهای پیچیده شده در داخل کندانسور و تأثیر همزمان آن بر میزان افت فشارچگالشی مبرد a134R- پرداخته می شود. هدف از این آزمایش رسیدن به بالاترین میزان انتقال حرارت در افت فشار بهینه می باشد. بدین منظور یک سیکل تبرید تراکمی بخار طراحی، ساخته و نصب شد. کندانسور تحت آزمایش یک مبدل حرارتی دو لوله ای بوده که قطر داخلی لوله میانی که مبرد R-134a در آن جریان د...

[ 3 ] - Experimental investigation on performance comparison of nanofluid-based direct absorption and flat plate solar collectors

In the present work, a prototype of a new type of solar collectors, which called Direct Absorption Solar Collector, was built and its thermal performance is experimentally compared with conventional flat plate solar collector under transient and steady state conditions. Different volume fractions of multi wall carbon nanotubes in water and ethylene glycol mixture (70%:30% in volume) were used a...

[ 4 ] - Direct Absorption Solar Collector using Carbon Nanotubes Nanofluid: An Experimental Investigation

In this study, the efficiency of direct absorption solar collector (DASC) using carbon nanotube nanofluid in the mixture of water and ethylene glycol as the base fluid was experimentally investigated and compared with the efficiency of the flat plate solar collector (FPSC). The results show that the maximum efficiency of the DASC using the base fluid and absorptive bottom surface is about 4.7% ...

[ 5 ] - Experimental investigation on performance comparison of nanofluid-based direct absorption and flat plate solar collectors

In the present work, a prototype of a new type of solar collectors, which called Direct Absorption Solar Collector, was built and its thermal performance is experimentally compared with conventional flat plate solar collector under transient and steady state conditions. Different volume fractions of multi wall carbon nanotubes in water and ethylene glycol mixture (70%:30% in volume) were used a...

[ 6 ] - Convective Heat Transfer of Oil Based Nanofluid Flow Inside a Circular Tube

Abstract   An empirical investigation was carried out to study convective heat transfer of nanofluid flow inside an inclined copper tube under uniform heat flux condition. Required data are acquired for laminar and hydrodynamically fully developed flow inside round tube. The stable CuO-base oil nanofluid with different nanoparticle weight fractions of 0.5%, 1% and 2% was produced by means of ul...

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