Overview
The aim of this work was to develop an innovative TEC for avionic application with maturity level TRL5, low power consumption and high efficiency and a combination of thermoelectric materials and energy harvesting techniques. The work will be based on the experience gained in previous works of the research team, concerning marine (ECOMARINE) and avionic (RENERGISE) environments and it will investigate advanced TE materials with ZT >>1, in multistage module configurations to cope with the harsh avionic environment and novel active control schemes to achieve high COP values.
Funding
Results
Executive Summary:
The aim of this project was to develop an innovative Thermoelectric Cooler (TEC) for avionic applications. The TEC prototype should reach a Technology Readiness Level of 5 (TRL5) and demonstrate low power consumption and high efficiency, while making use of a combination of thermoelectric materials and energy harvesting techniques. The work was based on the experience gained in previous works of the research team, concerning marine (ECOMARINE) and avionic (RENERGISE) environments and investigated advanced thermoelectric materials with high merit figures, in multistage module configurations to cope with the harsh avionic environment and novel active control schemes to achieve high performance (COP) values.
The consortium delivered a thermoelectric cooling (TEC) device at Technology Readiness Level 5 (a prototype validated in a relevant environment), using mainly commercial off the shelf (COTS) thermoelectric elements. The experimental procedure has evaluated an innovative double modulation frequency active PWM control method as a tool for the achievement of high thermoelectric cooling capabilities under harsh aeronautic conditions. Thanks to this method the TEC system manufactured meets the project requirements, proving that Thermoelectric Cooling is a promising technique for the aircraft industry.
In addition, the experimental process has shown that sophisticated control loops are necessary for a successful TEC system design under such harsh environmental conditions; meanwhile, TEC operation has to be active even under moderate temperature conditions, otherwise their cooling capability may be restricted in case of fast temperature rise (e.g. under the sudden raise of the consumption of the electronic equipment). Hence, a lot of research has to be made focusing on the control loop design and the incorporation of fuzzy / expert systems architecture.
Finally, the experimental procedure has been completed successfully, providing valuable data for further research and evaluating the effectiveness of the proposed control method. Although the outcomes for the average temperature values are generally in line with the corresponding simulation results, there are notable deviations between minimum / maximum temperature values. The main reason for this is the distribution of heat sources which was considered uniformly in the simulation model. In addition, there are some differences on the materials and the modification of the various system components between the simulation design and the experimental development. However, these differences can be justified by the research nature of the THERMICOOL project and consequently the fact that some system data were not fully determined during the simulation process.
Last but not least, the time consuming nature of the thermal experiments didn’t allow the complete validation of the last Case under study, however the initial laboratory tests indicate that its operation concept is correct making her a very promising technique for further study and development. In conclusion, the experimental procedure of THERMICOOL project has been successfully fulfilled, coming up with a novel active cooling method that meets the project requirements. In addition, enhanced control algorithms for multi-stage TEC schemes have been invented, calling for further research and development actions.