VALIDATION OF DISCHARGE AND PRESSURE HEAD OF COMPUTER MODEL TO IMPROVE SOLAR WATER PUMPING SYSTEM UNDER EGYPTIAN CLIMATIC CONDITIONS

Abstract

Multi steps computer program, ISWPS was designed for improving solar pumping systems under Egyptian climatic conditions. Step-7 of the Model was specialized to compute flow rate and head for photovoltaic pumping system under variable intensive solar radiation and high ambient air temperature. This study was carried out to validate the flow rate and generated head with the experimental data at the same incident solar radiation and ambient air temperature. The validation investigated under static head of 0 and 1 m for both flow rate and generated head. The experimental set-up consists of a stand-alone solar module, a pumping unit comprised a motor and a centrifugal pump (DC-PV pump). The predicted flow rate and water head obtained from ISWPS were validated under the same operating conditions. Statistical Packages for Social Science (SPSS) were used to validate the model with the experimental data (i.e. paired samples statistics, correlations and T-test for paired differences with 99% confidence interval). The study revealed that, the computation model estimated the flow rate and the water head especially under intensive solar radiation with an average deviations between measured and predicted flow rates of -3.73 % and -0.63 % at static head of 0 m and 1 m, respectively along six months from July till December. Meanwhile, the average deviations between measured and predicted head for the same period were -7.78 % and 1.53 % at static head of 0 m and 1 m, respectively.