An improved dynamic test method for solar collectors

Publication: Research - peer-reviewJournal article – Annual report year: 2012

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An improved dynamic test method for solar collectors. / Kong, Weiqiang; Wang, Zhifeng; Fan, Jianhua; Bacher, Peder; Perers, Bengt; Chen, Ziqian; Furbo, Simon.

In: Solar Energy, Vol. 86, No. 6, 2012, p. 1838-1848.

Publication: Research - peer-reviewJournal article – Annual report year: 2012

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Author

Kong, Weiqiang; Wang, Zhifeng; Fan, Jianhua; Bacher, Peder; Perers, Bengt; Chen, Ziqian; Furbo, Simon / An improved dynamic test method for solar collectors.

In: Solar Energy, Vol. 86, No. 6, 2012, p. 1838-1848.

Publication: Research - peer-reviewJournal article – Annual report year: 2012

Bibtex

@article{8f8628970b8545fe8180099a2ffc3137,
title = "An improved dynamic test method for solar collectors",
publisher = "Pergamon",
author = "Weiqiang Kong and Zhifeng Wang and Jianhua Fan and Peder Bacher and Bengt Perers and Ziqian Chen and Simon Furbo",
year = "2012",
doi = "10.1016/j.solener.2012.03.002",
volume = "86",
number = "6",
pages = "1838--1848",
journal = "Solar Energy",
issn = "0038-092X",

}

RIS

TY - JOUR

T1 - An improved dynamic test method for solar collectors

A1 - Kong,Weiqiang

A1 - Wang,Zhifeng

A1 - Fan,Jianhua

A1 - Bacher,Peder

A1 - Perers,Bengt

A1 - Chen,Ziqian

A1 - Furbo,Simon

AU - Kong,Weiqiang

AU - Wang,Zhifeng

AU - Fan,Jianhua

AU - Bacher,Peder

AU - Perers,Bengt

AU - Chen,Ziqian

AU - Furbo,Simon

PB - Pergamon

PY - 2012

Y1 - 2012

N2 - A comprehensive improvement of the mathematical model for the so called transfer function method is presented in this study. This improved transfer function method can estimate the traditional solar collector parameters such as zero loss coefficient and heat loss coefficient. Two new collector parameters t and mfCf are obtained. t is a time scale parameter which can indicate the heat transfer ability of the solar collector. mfCf can be used to calculate the fluid volume content in the solar collector or to validate the regression process by comparing it to the physical fluid volume content if known. Experiments were carried out under dynamic test conditions and then test data were processed using multi-linear regression method to get collector parameters with statistic analysis. A comparison of the collector parameters obtained from the improved transfer function (ITF) method and the quasi-dynamic test (QDT) method is carried out. The results show that the improved transfer function method can accurately obtain reasonable collector parameters. The influence of different averaging time intervals is investigated. Based on the investigation it is recommended to use on line calculation if applicable for the second-order differential term with 6–9min as the best averaging time interval. The measured and predicted collector power output of the solar collector are compared during a test of 13days continuously both for the ITF method and the QDT method. The maximum and averaging error is 53.87W/m2 and 5.22W/m2 respectively of the ITF method while 64.13W/m2 and 6.22W/m2 of the QDT method. Scatter and relative error distribution of the measured power output versus the predicted power output is also plotted for the two methods. No matter in either error analysis or scatter distribution, the ITF method is more accurate than the QDT method in predicting the power output of a solar collector.In conclusion, all the results show that the improved transfer function method can accurately and robustly estimate solar collector parameters and predict solar collector thermal performance under dynamic test conditions.

AB - A comprehensive improvement of the mathematical model for the so called transfer function method is presented in this study. This improved transfer function method can estimate the traditional solar collector parameters such as zero loss coefficient and heat loss coefficient. Two new collector parameters t and mfCf are obtained. t is a time scale parameter which can indicate the heat transfer ability of the solar collector. mfCf can be used to calculate the fluid volume content in the solar collector or to validate the regression process by comparing it to the physical fluid volume content if known. Experiments were carried out under dynamic test conditions and then test data were processed using multi-linear regression method to get collector parameters with statistic analysis. A comparison of the collector parameters obtained from the improved transfer function (ITF) method and the quasi-dynamic test (QDT) method is carried out. The results show that the improved transfer function method can accurately obtain reasonable collector parameters. The influence of different averaging time intervals is investigated. Based on the investigation it is recommended to use on line calculation if applicable for the second-order differential term with 6–9min as the best averaging time interval. The measured and predicted collector power output of the solar collector are compared during a test of 13days continuously both for the ITF method and the QDT method. The maximum and averaging error is 53.87W/m2 and 5.22W/m2 respectively of the ITF method while 64.13W/m2 and 6.22W/m2 of the QDT method. Scatter and relative error distribution of the measured power output versus the predicted power output is also plotted for the two methods. No matter in either error analysis or scatter distribution, the ITF method is more accurate than the QDT method in predicting the power output of a solar collector.In conclusion, all the results show that the improved transfer function method can accurately and robustly estimate solar collector parameters and predict solar collector thermal performance under dynamic test conditions.

KW - Solar collector

KW - Dynamic mathematical model

KW - Dynamic test method

KW - Solar collector parameters

U2 - 10.1016/j.solener.2012.03.002

DO - 10.1016/j.solener.2012.03.002

JO - Solar Energy

JF - Solar Energy

SN - 0038-092X

IS - 6

VL - 86

SP - 1838

EP - 1848

ER -