Optimum number and arrangement of evacuated-tube solar collectors under various operating conditions

2019 ◽  
Vol 199 ◽  
pp. 112032 ◽  
Author(s):  
Amr Kotb ◽  
Mahmoud B. Elsheniti ◽  
Osama A. Elsamni
Keyword(s):  
Operating Conditions ◽  
Optimum Number ◽  
Solar Collectors ◽  
Evacuated Tube

scholarly journals MEASUREMENT OF THE EFFICIENCY OF EVACUATED TUBE SOLAR COLLECTORS UNDER VARIOUS OPERATING CONDITIONS

2012 ◽  
Vol 7 (3) ◽  
pp. 114-130 ◽  
Author(s):  
S. E. Zubriski ◽  
K. J. Dick
Keyword(s):  
Environmental Conditions ◽  
Operating Conditions ◽  
Hot Water ◽  
Heat Transfer Fluid ◽  
Operating Efficiency ◽  
Space Heating ◽  
Solar Collectors ◽  
Auxiliary Equipment ◽  
Evacuated Tubes ◽  
Evacuated Tube

The operating efficiency of evacuated tubes themselves under varying environmental conditions and installation scenarios, independent of water and space heating auxiliary equipment, are not readily available values. Further, Manitoba specific data has not been established. The purpose of this research program was to measure the efficiency of evacuated tube solar collectors under various operating conditions including: the angle of inclination towards the incident solar radiation, heat transfer fluid flow rate, glazing installation, and number of evacuated tubes. The operating conditions and configurations were chosen to represent realistic or probable installation scenarios and environmental conditions. Furthermore, the research aimed to identify the suitability of evacuated tube solar collectors to each of the scenarios. These design values are of use for appropriate sizing of water or space heating systems, system configuration and optimization, and calculation of return on investment. The scope of the research project was limited to the efficiency of various configurations of a 32-tube panel, not the entire solar domestic hot water or space heating system. Thus, factors such as heat loss in the tubing, solar storage tank, and heat exchanger efficiency were not investigated. The findings indicated that efficiency varied by approximately 5% between the different collector configurations, as observed from the overlay graph of results. When the efficiency of a collector is considered within a system it is proposed that effectiveness may be a better measure of overall performance.

scholarly journals Assessment of the annual performance of solar collectors by means of the utilizability method

2020 ◽  
Vol 207 ◽  
pp. 02007
Author(s):  
Merima Zlateva
Keyword(s):  
Heat Transfer ◽  
Critical Value ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Solar Collectors ◽  
Different Temperatures ◽  
Evacuated Tube ◽  
Inclined Surface

This report presents some results from a comparative analysis of the long-term efficiency of flat-plate and evacuated tube solar collectors under different operating conditions. The analysis involves calculation of the daily utilizibility factor, which is defined as the fraction of total monthly solar radiation over an inclined surface that exceeds the critical value. The monthly values of the critical radiation and the daily utilizability factor for the solar collectors are determined under different climatic conditions and different temperatures of the heat transfer fluid. The obtained results are used to compare the annual performance of the solar collectors.

Evacuated Tube Heat Pipe Solar Collectors Applied to Recirculation Loop in a Federal Building: SSA Philadelphia

Solar Energy ◽  
2004 ◽  
Author(s):  
Andy Walker ◽  
Fariborz Mahjouri ◽  
Robert Stiteler
Keyword(s):  
Solar Energy ◽  
Heat Pipe ◽  
Heat Loss ◽  
Heating System ◽  
Hot Water ◽  
Solar Array ◽  
Solar Collectors ◽  
Water Heating ◽  
Evacuated Tube ◽  
Recirculation Loop

This paper describes design, simulation, construction and measured initial performance of a solar water heating system (360 Evacuated Heat-Pipe Collector tubes, 54 m2 gross area, 36 m2 net absorber area) installed at the top of the hot water recirculation loop in the Social Security Mid-Atlantic Center in Philadelphia. Water returning to the hot water storage tank is heated by the solar array when solar energy is available. This new approach, as opposed to the more conventional approach of preheating incoming water, is made possible by the thermal diode effect of heat pipes and low heat loss from evacuated tube solar collectors. The simplicity of this approach and its low installation costs makes the deployment of solar energy in existing commercial buildings more attractive, especially where the roof is far removed from the water heating system, which is often in the basement. Initial observed performance of the system is reported. Hourly simulation estimates annual energy delivery of 111 GJ/year of solar heat and that the annual efficiency (based on the 54 m2 gross area) of the solar collectors is 41%, and that of the entire system including parasitic pump power, heat loss due to freeze protection, and heat loss from connecting piping is 34%. Annual average collector efficiency based on a net aperture area of 36 m2 is 61.5% according to the hourly simulation.

scholarly journals Economic Feasibility of Flat Plate vs Evacuated Tube Solar Collectors in a Combisystem

2016 ◽  
Vol 91 ◽  
pp. 477-485 ◽  
Author(s):  
Mario Nájera-Trejo ◽  
Ignacio R. Martin-Domínguez ◽  
Jorge A. Escobedo-Bretado
Keyword(s):  
Flat Plate ◽  
Economic Feasibility ◽  
Solar Collectors ◽  
Evacuated Tube

Recent developments in design of evacuated tube solar collectors integrated with thermal energy storage: A review

2021 ◽  
Author(s):  
Muneesh Sethi ◽  
R.K. Tripathi ◽  
Birajashis Pattnaik ◽  
Sushil Kumar ◽  
Rohit Khargotra ◽  
...  
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Collectors ◽  
Recent Developments ◽  
Evacuated Tube

scholarly journals Design and Thermo-Economic Comparisons of an Absorption Air Conditioning System Based on Parabolic Trough and Evacuated Tube Solar Collectors

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3198 ◽  
Author(s):  
Adil Al-Falahi ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Air Conditioning ◽  
Thermal Power ◽  
Lithium Bromide ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Parabolic Trough ◽  
Solar Absorption ◽  
Pumping System ◽  
Economic Analyses ◽  
Evacuated Tube

Solar absorption cycles for air conditioning systems have recently attracted much attention. They have some important advantages that aid in reducing greenhouse gas emissions. In this work, design and thermo-economic analyses are presented in order to compare between two different collector types (parabolic trough and evacuated tube) by water–lithium bromide absorption systems, and to select the best operating conditions. Generally, the system consists of three major parts. The first part is the solar field for thermal power conversion. The second part is the intermediate cycle, which contains a flashing tank and pumping system. The third part is the water lithium bromide absorption chiller. A case study for a sports arena with 700–800 kW total cooling load is also presented. Results reveal that a parabolic trough collector combined with H2O–LiBr (PTC/H2O–LiBr) gives lower design aspects and minimum rates of hourly costs (USD 5.2/h), while ETC/H2O–LiBr configuration give USD 5.6/h. The H2O–LiBr thermo-economic product cost is USD 0.14/GJ. The cycle coefficient of performance COP was in the range of 0.5 to 0.9.

Optimal tilt-angles of all-glass evacuated tube solar collectors

Energy ◽  
2009 ◽  
Vol 34 (9) ◽  
pp. 1387-1395 ◽  
Author(s):  
Runsheng Tang ◽  
Wenfeng Gao ◽  
Yamei Yu ◽  
Hua Chen
Keyword(s):  
Solar Collectors ◽  
Evacuated Tube
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