Case example: Concept selection tool for evaluation of thermal insulation concepts Pauli Salminen Department of Engineering Design and Production
Thermal insulation is important for Solid Oxide Fuel Cell systems working at ~800 °C
Stack module
BoP module
• Experimental unit: Size is comparable to passenger car
Thermal insulation is thought to be simple and boring design task… … but it affects to other subsystems and properties in the test unit! – – – –
System layout Support of components Actuators Instrumentation
And finally it has a great effect on total electrical efficiency of the system!
Four insulation concepts were created
Selection tool systematically analyzes concepts and provides documentation Initial Data
Requirement prioritization
Weightings
Scorings 2
RESULTS+ANALYSIS
24 requirements were chosen for evaluation process • Quantative requirements: – Insulation efficiency – Low insulation surface area – …
• Subjective evaluation of requirements : – Component layout freedom – Serviceability of components – … Evaluation chart
Three things are critical for results: 1. Selecting requirements
• Group work • Requirements should be given as a positive manner
Three things are critical for results 2. Prioritization matrix and Weightings
Binary evaluation matrix (Paired comparison) +Easy to make +Simple -Binary evaluation is rough -Does not provide much information Analytical Hierarchy Process (AHP) would provide benefits
Three things are critical for results: 3. Evaluation (scoring)
• Group work • Scale! • Statistical tools?
RANK
Analysis of results is shown in charts
• Visual charts are better than numbers
Conclusions • Concept selection tool supports radical innovations which could otherwise be judged as silly or naive • This tool gives satisfactory results, but could be improved by implementing techniques like Analytical Hierarchy Process
Thank you!