1. The authors wish to acknowledge Eskom, DST, NRF and THRIP for their
financial support.
Presented at the 38th IEEE Photovoltaic Specialist Conference , 03-08 June
2012, Austin, Texas
Evaluation of an empirical model for a flat plate solar collector
Nothando Ndlovu, Michael Simon and Stephen L Tangwe
Institute of Technology, University of Fort Hare, Private Bag x1314, Alice 5700, SOUTH AFRICA
INTRODUCTION
• To propose and evaluate a simple, easy to apply black box multi linear regression
(MLR) model that can predict the outlet temperature of a solar collector.
EXPERIMENT
MEASURED AND MODELLED COLLECTOR OUTLET TEMPERATUTRE FOR
MODEL IDENTIFICATION
DISCUSSIONS AND KEY
CONCLUSION
MEASURED AND MODELLED COLLECTOR OUTLET TEMPERATURE FOR
MODLE VALIDATION
• Mathematical modelling has been widely used to
determine performance of solar thermal collectors.
• Designers and researchers are interested in
performance prediction of collectors for optimization
purposes.
• Physically based models and black-box models are the
two main categories in mathematical models.
• However, physically based models are generally
complex and time consuming to perform.
MODEL
• For parameter estimation data was collected on four
days 23-26/11/2014
• At the beginning of the experiment, the storage tank
was filled with cold water.
• The collector was left to heat up during the day and
the model variables measured in ten minute
intervals.
• This was repeated for all the days of data collection.
Validation data was collected the following month on
19/12/2014.
CollectorsTa and RH sensor
OBJECTIVE
SET UP RESULTS
IDENTIFIED MLR MODEL
Fig 2: Measured versus predicted output from MLR
output
Fig 3: Comparison of measured and modelled
temperature
Fig 4: Solar radiation and ambient temperature
19/12/2014
Fig 5: Comparison of measured and
modelled temperature 19/12/2014
Fig 1: Solar collectors on roof of Solar Watt house
• The modelled system consists of 2 x 2𝑚2
Flat plate
collectors installed in parallel on a North facing roof in
Alice, South Africa. The storage tank capacity was
200litres installed inside the roof.