Performance Analysis and Design Optimization of a Mini-Channel Evacuated-Tube Solar Collector

2008 ◽  
Author(s):  
Gerardo Diaz
Keyword(s):  
Solar Collector ◽  
Renewable Energy Sources ◽  
Geometrical Parameters ◽  
Thermal Systems ◽  
Round Tube ◽  
Selective Coating ◽  
Analysis And Design ◽  
Evacuated Tube Solar Collector ◽  
Performance Analysis And Design ◽  
Evacuated Tube

The utilization of renewable energy sources is receiving considerable attention as a non-resource-depleting approach that reduces the emissions of pollutants and green-house gases to the atmosphere. Solar thermal systems have the capability to provide heat in a sustainable way for a variety of applications due to the relatively large range of temperatures that different collector configurations can attain. Most evacuated-tube solar collectors currently found on the market consist of a u-shaped round tube, concentric round tubes in counter flow regime, or a heat-pipe. The external surface in these designs is welded to a thin absorber fin that is covered with a selective coating. This paper analyzes the performance of an evacuated-tube solar collector that contains a U-shaped mini-channel tube. Comparisons of performance with respect to standard u-shaped round-tube solar collector are made. The design of a mini-channel based solar collector without absorber fin is also analyzed and its performance optimized with respect to its geometrical parameters.

scholarly journals ANALISYS OF THERMAL EFFICIENCY OF A MODIFIED SOLAR COLLECTOR TYPE EVACUATED TUBE

2014 ◽  
Vol 13 (1) ◽  
pp. 03
Author(s):  
E. Avallone ◽  
A. I. Sato ◽  
V. L. Scalon ◽  
A. Padilha
Keyword(s):  
Solar Collector ◽  
Renewable Energy Sources ◽  
Experimental Tests ◽  
Clean Energy ◽  
Hot Water ◽  
Energy Sources ◽  
Transient Heat Flow ◽  
Important Approach ◽  
Experimental Problem ◽  
Evacuated Tube

The need of renewable energy sources due to climate change and thus the search for clean energy sources, justify the growing investment on new types of solar collectors. The research has contributed to this expansion in the scope of solar concentrator collectors, with the efficiency as the main goal. Many works have been developed in order to optimize the thermal stratification of the fluid inside the tubes and heat reservoirs, as well as mathematical modeling considering the problem as transient heat flow as boundary condition. In this work is studied experimentally, the heating of the water by solar collector modified from the conventional evacuated tube, focusing on efficiency. With the help of CFD software, a theoretical analysis is done to visualize the phenomenon, assuming the same boundary conditions and geometric experimental problem. An important approach concerns the physical separation of the flows of both cold and hot water inside the evacuated tube. The system performance was analyzed using experimental tests performed outdoors with sunlight.

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