Mathematical Modelling of the Thermal Accumulation in Hot Water Solar   Systems
  Mathematical modelling and defining useful recommendations for construction and regimes of exploitation for hot water solar installation with thermal stratification is the main purpose of this work. A special experimental solar module for hot water was build and equipped with sufficient measure apparatus. The main concept of investigation is to optimise the stratified regime of thermal accumulation and constructive parameters of heat exchange equipment (heat serpentine in tank). Accumulation and heat exchange processes were investigated by theoretical end experimental means. Special mathematical model was composed to simulate the energy transfer in stratified tank. Computer program was developed to solve mathematical equations for thermal accumulation and energy exchange. Extensive numerical and experimental tests were carried out. A good correspondence between theoretical and experimental data was arrived. Keywords: Mathematical modelling, accumulation 
Stanko Vl. Shtrakov, Anton Stoilov