DEARSUN

DEARSUN – A Solar Heating System using High Temperature Thermal Storage (FP7), 2008 – ongoing

Development of a Direct Solar Heating System Capable of Covering a Full Year Thermal Load Using High Temperature Thermal Storage.

The main objective of the DEARSUN project is to design, develop, build and test a new concept of solar heating system, using high temperature thermal storage of up to 105°C, able to supply the full year thermal load (space heating plus domestic hot water production) of a building without, to a large extend, any auxiliary heat source. One of the pilar concepts of the DEARSUN system is to work with a fluid that can support high temperatures (around 150°C) without vaporizing. As a consequence, the termal storage system has to withstand these high temperatures and should not be affected (corrosion) by the selected fluid for the application.

A prototype of storage tank has been designed and manufactured. Several initial conceptual designs were modelled and different material possibilities for the vessel walls and insulation layers were compared. The final design for the prototype manufacturing was selected taking into consideration the heat transfer fluid, the maximum working temperature, and the maximum working pressure. FEM simulations were performed in order to define the best insulation strategy that could withstand the high temperature levels met in the system. Four tanks were built during this first year, using a combination of arc welding and laser welding.