In the domain of aeronautical security, one of the main energy contributors is the anti-icing system. Several zones must be protected against icing and one of these is the engine air intake. Two technologies are used nowadays for this function: the first one uses directly hot air coming from the engine to be brought on the back of the surface to be protected and the second one uses electric heaters on the same surface. Both are costly in terms of fuel consumption. PIPS project proposes a new technology in this domain. We propose to transport energy, which is currently not used, from hot air in the engine zone to the protected surface by the means of a two-phase system. This passive but highly efficient heat exchanger, utilizes the phase-changes of a thermal fluid and a capillary pump to bring the heat from one zone to another in a closed metallic loop.
The PIPS project addresses the specific aeronautical challenge relative to the improvement and optimization of nacelle/engine integration to save weight and fuel consumption thanks to high technology devices leading to significant CO2 savings.
The ultimate goal of this project is to replace the today ice protection systems mounted on the surfaces of engine intakes by a two-phase passive thermal system with the following main benefits:
• Reduction of fuel consumption and raise of the engine effectiveness using a highly efficient thermal system for the extraction of heat from the engine to the protected surface (high heat transfer capacity compared to the two-phase system mass);
• Decrease of mass and ease of thermal icing protection integration by removing the today electro-thermal and pneumatic usual device used to collect power from the engine;
• Increase of reliability of a critical function such as anti-icing by reducing active control and operations;
• Lower impact on environment and operating cost reduction by using a passive thermal system which is maintenance free.
At two-phase system level, the main innovation was the development of a novel system, derived from a space technology, to the specific aeronautical requirements. Materials, architecture and functioning are novel and are under patent application.
TRL6 was reached for the two-phase product to enable the European aeronautical communities to propose more efficient aircrafts with less environmental impacts.
Icing wind tunnel tests has proved the concept and the efficiency of the technology under relevant condition at full scale (icing and low temperature high speed wind) on most parts of the zone to be protected. Nevertheless, some parts were not properly de-iced due to bad distribution of heat on the zones to protect. Slight design modifications of the condenser are proposed to eventually achieve higher TRL levels.
The most relevant characteristics assessed and managed through this project were:
• The severe and highly variable thermal and mechanical environment around the engine and its nacelle and
• The specific geometry of the protected surface.
This project will so contribute to the strengthening of the competitiveness of the European industry by introducing two-phase heat management systems contributing to the reduction of CO2 emissions and airplane noise, toward an eco-conception and an eco-utilization point of view.
