Wyniki wyszukiwania - BazTech

1

Comparing the efficiency of evacuated tube and flat-plate solar collectors in real installation conditions

Jurczak Marlena Anna, Skotnicka-Siepsiak Aldona

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

|

2020

|

Vol. 9 Nr 2

31--38

EN

The subject of the work is an analysis of two types of solar collectors: flat-plate and evacuated tube collectors in the same, natural working conditions during the period from 1st May 2017 to 30th September 2017. The scope of work includes a descriptive presentation of a measuring setup, located on the roof of the building of the Construction University of Warmia and Mazury in Olsztyn, and also the research methodology, as well as an analysis of the results and conclusions obtained. The measurements allow a comparison of the efficiency of the flat-plate and evacuated tube collectors by calculating heat yields, based on the following variants: average hourly irradiation, outdoor air temperature, temperature of the medium supplying the collectors and temperature of the returning medium. An analysis of the heat yield was made in relations to the individual absorber surface, to determine which of the tested collectors showed higher efficiency under real operating conditions during the spring-summer period.

2

Analiza wpływu właściwości termofizycznych absorberów na sprawność cieplną płaskich cieczowych kolektorów słonecznych

Błażejewski A., Kamiński K., Krzyżyński T.

TTS Technika Transportu Szynowego

|

2013

|

R. 20, nr 10

1995--2004, CD

PL

W artykule przedstawiono wyniki porównania efektywności cieplnej płaskich kolektorów słonecznych wyposażonych w absorbery wykonane z miedzi oraz aluminium. Zaprezentowano wyniki analizy CFD rozkładu temperatury na powierzchni miedzianych i aluminiowych absorberów i omówiono wpływ współczynnika przewodzenia ciepła absorbera na efektywność cieplną płaskich kolektorów słonecznych.

EN

Paper presents the comparison of thermal efficiency of solar collectors witch copper and aluminum absorbers. CFD results of temperature distribution on copper and aluminum absorber surface have been shown in order to explain the influence of thermal conductivity coefficient on solar collector efficiency.

3

Simulation of the influence of design and meteorological factors on the efficiency of a solar plate collector

Dobriański J.

Archives of Thermodynamics

|

2009

|

Vol. 30, no. 3

45-74

EN

A mathematical model of heat transfer between the components of a solar collector and the surroundings is proposed. The model consists of the equations of heat balance for glass-covers, absorber and the rear side of a collector, as well as the heat transfer from the absorber to the heat carrying medium inside the collector. The heat balance equations take into consideration solar radiation, conduction, convection and infrared radiation between the components of the collector and its surroundings. Heat flow is calculated for solar collectors with two-glass and single-glass covers and the case where there is no cover. The subject of the investigation was to analyse the influence of different design characteristics (physical properties of materials, thickness of particular elements, distances between them) and parameters of surroundings on the efficiency of the collector. The optimal values of thickness of insulation and distances between the glass covers and the absorber, as well as other parameters were specified. The best conditions for using a collector with a double glass cover, with one glass cover and without any transparent cover were analysed. A solar collector performs better with a two-glass cover than with only a single-glass cover if the collector does not have a selective coating or if the temperature of the heat-carrier is high enough. This difference in performance, however, is not significant.