Autonomous thermal switch

Time period: 2015-11-09 to 2016-07-09

Project leader: Hans-Olof Blom

Funder: Vinnova

Type of award: Project grant

Total fundning: 292 679 SEK

Purpose and goal: The goal for this project is to investigate the possibility to develop an autonomic thermal switch. The long-term goal is that APR Technology should be able to manufacture and sell this component that today are not found commercially available. Prototypes that fulfill the demands of isolation in OFF mode have been manufactured. The heat conduction in ON mode is not sufficient. However, it is close enough and it is judged that it will be possible to develop and manufacture a switch that will fulfill the demands. Expected results and effects: A number of prototypes have been manufactured and tested. The design is in general like a hockey puck with a cavity filled with paraffin. The cavity is covered with a membrane. When the switch gets warm the paraffin melts, expands and activates a thermal path through the structure. The isolation fulfills the demands but not the heat conduction. Further development of the component is therefore necessary. Approach and implementation: Several prototypes have been manufactured and tested. The results from the tests have been compared to simulations and calculations. The results from the comparisons have been used for the design of the next prototype. The result of this process is that the prototypes have become better and better. However, some improvements remain before the component will fulfill the demands.