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...

The effect of the volume flow rate of the heat transfer fluid (air) on the thermal parameters of the solar air collector with a single air pass without using fins under the absorbing plate have been investigated experimentally and theoretically. We use a new design of solar air collector which aims to optimize these parameters in the region cited above. Our solar air collector was realized at t...

In this paper, a multi-objective optimization method is implemented by using of genetic algorithm techniques in order to determine optimum configuration of solar chimney power plant. The objective function which is simultaneously considered in the analysis is output power of the plant. Output power of the system is maximized. Design parameters of the considered plant include collector radius (R...

This paper deals with the performance of a heat pipe solar collector. The solar collector consisted of an interconnected heat pipe so as to reduce the production cost by using an interconnected heat pipe because all the heat pipes can be evacuated, sealed and tested at once. Performance of a prototype of the heat pipe solar collector was experimentally examined, and the results were compared wi...

Solar chimney power plants are plants based on solar thermal power including three parts of collector, chimney and turbine, which is able to produce electrical energy. One of the effective parameters in increasing the power production is the collector angles versus horizon. In the present study, a numerical analysis of a solar chimney power plant for different angles of the collector (divergent...

This paper reports the thermal performance of a new cylindrical solar collector based on an experimental investigation with this difference that instead of the collector tube with absorbent coating, coil into a spiral copper tube is placed in the center of the collector. The spiral shape of the tube, heat transfer without disruption or increase the heat transfer area, is increasing. In this cas...

Solar cookers are aimed at reducing pollution and desertification in the developing world. However, they are often disregarded as they do not give users the ability to cook after daylight hours. The Wilson solar cooker is a solar cooker designed to address this problem by converting solar energy and storing that energy as heat in the form of molten salt (lithium nitrate). This thesis involved r...

This study compares environmental and economic impacts of using nanofluids to enhance solar collector efficiency as compared to conventional solar collectors for domestic hotwater systems. Results show that for the current cost of nanoparticles the nanofluid based solar collector has a slightly longer payback period but at the end of its useful life has the same economic savings as a convention...

nowadays two important discussions in academic parties all over the world are energy crisis and environment crisis. one of the strategies to deal with these crisises is using clean, renewable and domestic energy sources. one of the best renewable energies that can be used in different scales is solar energy. in iran which is considered among the greatest countries that receive huge amount of so...