SOFC APU systems development 1
Original Language Title: SOFC APU System Entwicklung 1
During the operation of heavy goods vehicles (HGVs) the energy consumption of vehicle and load unit components, such as heating and cooling, on-board electronics or cargo conditioning, contribute significantly to the truck's energy consumption. These consumers are frequently served by auxiliary power units (APUs) in order to remain independent of the vehicle’s power train.
The ASyS1 project has 4 main goals:
- Presentation of a self-sufficient SOFC (solid oxide fuel cell) APU (Auxiliary Power Unit) system with 2-3 kW power generation, using metal-supported SOFC technology and anode recirculation with a hot gas blower.
- Analysis and modeling of common defects to develop faster testing methods.
- Concepts for electric, thermal and mechanic integration into the vehicle
- Identify optimized operating processes, in particular for deposit removal within the system
The ASysI project led to significant technical progress towards competitive SOFC APU systems. For the first time a fully stand-alone prototype system has been built up and successfully tested for a hundreds of hours. The ASysI development efforts have been awarded with the Styrian Innovation Prize "Fast Forward Award 2012" and was finalist in the National Austrian Prize for Innovation 2013.
At the beginning of the project, requirements and specifications for the APU system were simulated by a stationary system simulation. The APU system has been designed to fulfill all requirements from the truck industry.
Using the AVL reliability development tool Load Matrix, all relevant failure mechanisms were identified and analyzed. Furthermore a test program to validate the system towards reliability / durability has been elaborated. Essential knowledge regarding the cell reliability and a proprietary “regeneration procedure” was developed based on SOFC single cell tests at the Institute of Thermal Engineering (IWT). Together with the US truck industry, a vehicle integration concept was designed and a controller was developed for fully automatic SOFC APU system operation.
First APU prototype systems were developed and built up with FE simulation support from the Institute of Lightweight Design (ILB). The main achievement was a completely stand-alone APU system operated with diesel fuel and 2kW of output power at around 30% efficiency. The packaging concept of the SOFC APU gen I was designed for the installation of two SOFC stacks, which will increase the power output in future to 4 kW. In all system tests well over 1,000 operating hours were achieved. Finally a long-term system vibration test was successfully performed at ILB based on real world bad road and normal highway vibration profiles.
AVL List GmbH
Graz University of Technology, Institute for Lightweight Design
Dr. Thomas Thurner
Graz University of Technology, Institute of Thermal Engineering
Univ.-Prof. Dr.-Ing. Jürgen Karl