Energy analysis of a combined solar wood drying system

This work proposes a hybrid solar dryer model combining a heat pump and a concentrated photovoltaic thermal using air as a cooling fluid for the solar cells. The proposed system will be able to simultaneously produce electricity and heat necessary to conduct the wood drying operations. Mathematical models are developed, verified and validated for the various components constituting the combined system. The discrepancy between measurement and theoretical results did not exceed 8%. The results showed that the combined system can reduce the drying time up to 18%, compared to the drying method using the heat pump alone. Effect of drying parameters on system performance was analyzed. The results demonstrated that the overall efficiency of the concentrated photovoltaic thermal system ranged from 34 and 52%. Compressor operating hours increased as mass flow rate increased. The electricity saving and the moisture extraction rate improved by 57 and 39% by increasing the regenerator efficiency from 25 to 75%, respectively. The proposed system could significantly reduce the power consumption of hybrid solar dryers and can compete effectively with solar models described in the literature.