Skip to main content
European Commission logo
English English
CORDIS - EU research results
CORDIS
CORDIS Web 30th anniversary CORDIS Web 30th anniversary
Content archived on 2024-05-30

Thermoelectric cooling using innovative multistage active control modules

Final Report Summary - THERMICOOL (Thermoelectric cooling using innovative multistage active control modules)

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.

Project Context and Objectives:
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.

Project Results:
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.

Potential Impact:
Overview
The results of the project contribute to the vision of the all-electric aircraft (AEA) and the reduction of carbon and other undesirable emissions through improved overall systems energy efficiency by exploitation of new electrical system technologies. The adoption of AEA in the future aircraft both in civil and military sectors will result in tremendous benefits such as:
• Removal of hydraulic systems, which are costly, labour-intensive, and susceptible to leakage and contamination problems, improves the aircraft reliability, vulnerability, and reduces complexity, redundancy, weight, installation and running cost
• Deployment of electrical starting for the aero-engine through the engine starter/generator scheme eliminates the engine tower shaft and gears, power take-off shaft, accessory gearboxes and reduces engine starting power especially in the cold conditions and aircraft front area
• Utilization of the Advanced Magnetic Bearing (AMB) system, which could be integrated into the internal starter/generator for both the main engine and auxiliary power units, allows for oil-free, gear-free engine area
• In AEA, using a fan shaft generator that allowing emergency power extraction under windmill conditions removes the conventional inefficient single-shot ram air turbine, which increases the aircraft’s reliability, and survivability under engine-failure conditions
• Replacement of the engine-bleed system by electric motor-driven pumps reduces the complexity and the installation cost, and improves the efficiency
In general, adopting AEA will revolutionise the aerospace industry completely, and significant improvements in terms of aircraft-empty weight, re-configurability, fuel consumption, overall cost, maintainability, supportability, and system reliability will be achieved. On the other hand, the AEA requires more demand on the aircraft electric power system in areas of power generation and handling, reliability, and fault tolerance. These entails innovations in power generation, processing, distribution and management systems
Within the transport sector, air transport has the fewest options for the shift to greener technologies. Globally, aviation currently accounts for around just 2% of man-made CO2 emissions, compared with 16% from other forms of transport and over 30% from electricity and heat supply. Future emissions levels from each sector will depend on the relative rates of growth and the scale of technological improvements. The prediction is that net aviation emissions will continue to increase if radical technological improvements beyond that anticipated today are not forthcoming. Within the indirect results of the THERMICOOL project are:
• New technologies, which radically improve the environmental impact of air transport;
• Increase of the competitiveness of European industry, contributing to the Lisbon Strategy objectives;
• Enabling the aviation world to make greener products.
Trends in aircraft industry
Aeronautics is one of the EU’s key high-tech sectors on the global market:
• it provides more than 500 000 jobs and generated a turnover of close to EUR 140 billion, in 2013;
• the EU is a world leader in the production of civil aircraft, including helicopters, aircraft engines, parts and components;
• the EU has a trade surplus for aerospace products, which are exported all over the world.

The industry is highly concentrated, both geographically (in particular EU countries) and in terms of the few large enterprises involved. Employment in the aerospace sector is particularly significant in the United Kingdom, France, Germany, Italy, Spain, Poland and Sweden. Productivity is considerable and despite high employment costs, the sector is quite profitable. A sizeable share of value added is spent on research and development (R&D), which is reflected in an increasing number of patent applications.
The characteristics of the industry have so far re-shaped vertical relations (the production pyramid). In the civil aviation markets, Boeing and Airbus (EADS) now concentrate on product and system integration and the management of the supply chain as a core competency (as well as customer relations). They have started to shift system integration to first-tier suppliers. They are also forcing their suppliers to take more responsibility for the development and design process (and asking to share non-recurring costs) and the associated programme and currency risks. At the same time, they offer long-term relations, with stable and reliable relationships, and run electronic links with suppliers. On the other hand, the technological level is so high that there is no single technology that will drive future developments. In contrast, new aircraft will probably be more influenced by innovations between the various systems and by manufacturing technologies. The substantial costs associated with new developments will therefore lead to a further widening of the collaboration network already found in the sector. Finally, there is a shift from cost reductions to securing quality and endorsing the various strategic chances offered by specialised firms all over the world, along with the potential market access offered by these firms. In a nutshell, the suppliers need to reduce costs, improve the technological level, and guarantee a higher quality and service level to the customer. These changes are particularly challenging for SMEs, which have been operating in the sector for some time. These factors are pushing the suppliers towards the creation of supply networks, which incorporate various skills and competencies to meet customers’ requirements. Within these networks the leader firm will directly communicate with lower-tier suppliers, creating a new channel of interaction. The model will change from a linear model to a more “unstructured”, network-like model.
Competitiveness of the participants
It is evident that the key and innovative technologies developed within THERMICOOL will offer ITC, and MILTECH know-how, skills, competitive advantages and a set of pre-commercial prototypes, which will most likely evolve into marketable and profitable products for the aerospace industry.
Contribution to community social objectives
The public benefits that the THERMICOOL project will offer are summarized as follows:
• Eliminating the use of toxic fluids in hydraulic systems may result in improving of quality of life of people using these products in terms of health and safety.
• Improving of working conditions for engineers and all other personnel involved in aircraft manufacturing and industry.
• Positive environmental impact, as the main goal is the effective reduction of emissions.
THERMICOOL will enable new business opportunities in continuous evolving industrial sectors like aerospace and automotive, which will improve employment prospects and the level of skills in Europe.
Impact on Participants: ITC
ITC S.A. is a leading research and development company for innovative turn-key solutions and cost-effective products. The company was established in 1994 and specialises in the leading edge areas of Industrial Automation, Embedded Systems, Energy Harvesting/Recovery and Environmental Modelling. ITC’s technical excellence and professional expertise achieve the optimal solutions for its customers. Firmly established in a highly competitive global market, challenging projects have successfully been completed with major international industries including ALCATEL-LUCENT, MOTOROLA, ARAMCO, QATAR CAA, and SOLINET GmbH. ITC is active in the energy domain by developing control electronics and software for on-board applications such as:
• Industrial Power Factor Correction and Energy Recovery
• Development of thermoelectric generators for marine applications
• Design and development VHDL blocks and embedded SW for industrial applications
• Design and development of a customisable PV configuration and modelling software
ITC will use the knowledge gained within THERMICOOL in the design and implementation of advanced software and hardware solutions in the aeronautical domain towards extending the market opportunities both in the standalone exploitation line of its subsystems and through the alliance with major partners in the aeronautics industry for future products. Furthermore, the expertise and actual products developed will be exploited in the other business areas in which ITC is active, such as energy recovery applications.
Impact on Participants: MILTECH
MILTECH HELLAS S.A. is a private modern, dynamic electronics industry in the area of high technology avionics, thermal imaging, telecommunication products & accessories, aircraft harnesses and other special purpose electronics applications. Among its selection of products MILTECH designs, manufactures and installs 32KW, 400Hz Power Converter for the Sort Range Air Defense System CROTALE /NG/GR, 25KW Static Power Converter MLT-NSFC-25/400 for the Combat Navy Ships of the Hellenic Navy and other demanding electronic products.
Giving great emphasis to the quality of the final product MILTECH has developed a "Quality Assurance System" according to EN ISO 9001:2000 certified by CERTO and EN9100 certified by MIRTEC & CERTO for aerospace supplies. Its customers include Dassault Aviation Hellenic Aerospace Industry, INTRACOM, SELEX, AERMACHI in Italy, THALES (TAS, TR6, TES), EUROCOPTER, MBDA in France, STN-ATLAS, KMW, REINMETAL in Germany, ROCKWELL COLLINS, B.A.E. and M.D.S. in the United States.
MILTECH already exploits the technologies developed within Clean Sky project RENERGISE and demonstrated at the ‘Copper Bird’ facilities. The THERMICOOL project, is evidently within the core priorities for the future MILTECH product line and will offer the company know-how, skills, competitive advantages and a set of commercial prototypes, which will most likely evolve into marketable and profitable products for the aerospace industry.
Impact on Participants: DUTH
As an academic institution, all the work done targets in the know-how acquisition in the scientific areas mentioned above. A several number of people work or have worked in DUTH for various projects as permanent research associates, Ph.D. researchers or electrical engineering graduates working on their diploma project. Many of these projects were funded from third party research institutes, from the European Union, from state scientific organizations and the local or foreign industry. Besides all the acquired knowledge through the years, DUTH's work resulted in more than 1,000 diploma thesis completed already, in over a 200 MSc and Ph.D. diplomas and in a large number of publications (more than 2,500) in world-wide distinguished scientific journals and conferences.

Publications
A paper entitled “Thermoelectric cooling for avionics applications using active control modules”, was submitted for publication in the IEEE Access Journal (via the Openair Project support scheme).

List of Websites:
http://itcnet.gr/en/clean-sky-thermicool-ga-no-632436/

Professor Michael Loupis
ITC sa
25 Alketou str
GR-11633 Athens, Greece
Tel. +302107560322
email: mloupis@itcnet.gr
final1-thermicool-publishable-summary.pdf