CFD Calculations and PIV Measurements on Tank-in-Tank Heat Store
Abstract
Theoretical and experimental investigations of a tank-in-tank heat storage for a solar combisystem have been carried out. The investigated combistore is designed for PIV measurement studies. The theoretical investigations are carried out by means of the Computational Fluid Dynamics CFD code Fluent 6.1 . The tank-in-tank heat storage is a tank where the domestic hot-water (DHW) tank is placed in the space heating storage tank. The space heating storage tank is heated by the solar heat by circulating water through the outer tank. Heat is transferred from the space heating storage tank to the DHW tank through the tank wall of the DHW tank. A model of the heat storage tank used for experimental studies has been built up in the CFD program. The fluid motion and the thermal conditions for the heat store have been investigated during different operation conditions. It has been analyzed how the thermal stratification in the space-heating storage and DHW tank during periods with hot water consumption is influenced by hot water draw-off.