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M. Jakobi, B. Geringer, P. Hofmann:
"Chemical Heat Storage for Automotive Heating and Cooling Applications";
Talk: 3rd IAV Conference: Thermoelectrics goes Automotive, Berlin, Ellington Conference Center; 2012-11-21 - 2012-11-23; in: "Thermoelectrics Goes Automotive II (Thermoelectrics III)", expert Verlag, (2012), ISBN: 978-3-8169-3169-0; 57 - 73.

This article presents various investigations undertaken during the FVV project "Restwärmenutzung durch intelligente Speicher- und Verteilungssysteme (Utilization of Waste Heat by Intelligent Storage and Distribution Systems)", which took place from October 2009 to May 2012. In addition to a basic literature study, a heat storage test bench and a prototype heat storage system based upon the chemical storage principle were built up to make further investigations. Explicit information as well as detailed results are included in the final report.
The aim of this project is the storage of waste heat of internal combustion engines and utilization at the next cold start to minimize the warm-up period in order to reduce the fuel consumption of cars. A new and innovative heat storage system should help
to compensate various problems, such as low storage density, the need of thermal isolation of storage medium, losses at long parking duration and the difficult placement in the vehicle on the one hand as well as to improve different important criteria on the other. The literature study showed that reversible chemical reactions, which proceed under supply or release of thermal energy, are generally
able to store heat. Besides the loss-free storage over long periods and the higher energy density in general, this technology can also be used to climatize (aircondition) the car.
A specially developed heat storage test bench was built during the project and furthermore intensive investigations with different chemical reactions were carried out. Thereby, reaction characteristics and heat dissipation were analysed. An
important criterion is the course of the reactions at low temperatures down to -15 °C.
Subsequently, a prototype storage system was developed, which permits
investigations similar to vehicle applications. Thus, various measurements with different reaction parameters were performed as well as different steps for process optimization.
Research results demonstrate that the usage of waste heat by chemical reactions based on salt hydrates is generally possible in automotive applications. Additionally, it seems to be an interesting area for further investigations to increase the overall efficiency.