Optimization of solar heating and water heating combi-systems applied in buildings

The project will be carried out by Beijing Solar Energy Research Institute Co. Ltd, China and Department of Civil Engineering, Technical University of Denmark. The Chinese partner will focus investigations on flat plate solar collectors and the Danish partner will focus on evacuated tubular solar collectors. The thermal performance of the different collectors will be compared both for Danish and Chinese climate. The Chinese partner will focus on traditional designed heat stores without a high degree of thermal stratification. The Danish partner will focus on highly stratified heat stores with built in inlet stratification devices. It will be elucidated how much the thermal performance will be improved for solar combi systems with advanced stratified heat storages instead of normal heat storages with limited thermal stratification both with Danish and Chinese weather data. Laboratory tests of solar combi systems, development of TRNSYS simulation models for solar combi systems and validation of the simulation models will be carried out. Solar combi systems will be developed based on TRNSYS calculations both for Danish and Chinese weather data and one family houses. The long term thermal performance of solar combi systems installed in demonstration houses in China and in Denmark will be measured