Impact of solar energy application on improving the energy performance of continuous-flow heat pump grain dryers

<ns0:p>Grain drying is an essential stage of post-harvest processing. Utilizing renewable energy sources, particularly heat pumps combined with solar energy, is one of the methods for improving the process's energy efficiency. Brief information is provided on the use of heat pumps in combination with various approaches to solar energy utilization. A detailed schematic diagram of a continuous-flow grain dryer is considered, which involves the sequential use of two drying agent heating systems: a solar air heater and a heat pump. Within the scope of this article, an analytical model for determining the energy efficiency of this schematic solution is presented along with the calculation results. Recommendations are provided for the optimal use of the heat pump in combination with the solar heater in continuous-flow dryers with drying agent recirculation. The research findings will be useful for further scientific research and for developers of modern grain drying systems.</ns0:p>