المجلة الدولية للعلوم والتقنية

The solar water heater system is an integrated system that utilizes solar radiation to heat water. The use of solar heaters has become necessary for solar efficient energy consumption. In this study, the second law of thermodynamics was used as principle for mathematical modeling and analysis of a solar collector as the main component of a solar water heater System. The modeling and simulations were managed using MATIAB software. The results of this study were compared to available references, and a good agreement was observed. The conclusions revealed the discrepancies between the analysis based on the principle of energy conservation and the quantitative analysis of exergy quality and efficiency. The efficiency of the thermal energy (quantity) for The collector was calculated to be 46% while the efficiency of its quality was 3.8%. This confirms that when designing solar water heaters, it is important to prioritize improving the quality of the thermal energy alongside it's quantity, while considering the cost. Conducting an economic quality study is recommended. The modeling and simulation program achieved high credibility, enabling a parametric study to be conducted to examine .The influence of changing parameters such as inlet temperature and radiation intensity on the efficiency. Keywords: Flat plate solar collector – Exergy - Efficiency- Matlab - Steady state.