  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
