Overview
The proposed project was part of the Cleansky activities for the “More electric” aircrafts.
Such aircrafts require more power electronics integration and so “traditional” cooling systems (natural or forced convection, liquid loops) may reach their maximal performances because of the too high thermal dissipation density of these components. A need of heat spreading was clearly identified by the users.
In this way, two-phase fluid capillary pumped heat transfer systems appear as more efficient alternative solutions thanks to their high heat transport capacity and their passive pumping capacity.
Several passive cooling systems can be considered for these applications such as vapour chambers, heat pipes and high temperature loop heat pipes. Such systems have background on space systems and environments; however, the demonstration of their functioning in avionic application, by modelling and experimental tests, is required before being equipped on an airplane.
The EHP proposal addressed the development, design, manufacturing and demonstration in a relevant environment - TRL6 (technology Readiness Level) - of a two-phase passive cooling system to be used on aeronautical applications.
The size of equipment to be cooled is close to an A4 format.
One hundred of watts are dissipated over several localised areas with a heat flux density around 30W/cm².
The equipment was located in a harsh environment characterized by an ambient temperature of
160°C and a low heat exchange coefficient. Despite these conditions, the equipment maximal temperature should not exceed 200°C.
The EHP activities consisted in the following points:
- Bibliographic review
- Technology selection
- Fluid selection
- Cooling system sizing / modelling
- Prototype construction
- Experimental validation
Funding
Results
Executive Summary:
The proposed project was part of the Cleansky activities for the “More electric” aircrafts. Such aircrafts require more power electronics integration and so “traditional” cooling systems (natural or forced convection, liquid loops) may reach their maximal performances because of the too high thermal dissipation density of these components.
A need of heat spreading was clearly identified by the users.
In this way, two-phase fluid capillary pumped heat transfer systems appear as more efficient alternative solutions thanks to their high heat transport capacity and their passive pumping capacity.
Several passive cooling systems can be considered for these applications such as vapour chambers, heat pipes, high temperature loop heat pipes. Such systems have background on space systems and environments; however, the demonstration of their functioning in avionic application, by modelling and experimental tests, is required before being equipped on an airplane.
The developed technology in the HTCS program corresponds to a thermal system for aeronautical applications based on two-phase heat spreading, meaning that the heat is evacuated thanks to vaporization and condensation of a fluid contained in the thermal device. This device is passive so that no electrical input is necessary to make it function, its activation is only due to the heat dissipation. Effective spreading of the heat offers an elegant and performant way to reduce electronic equipment temperatures or increase their waste heat power
The integration of such a two-phase thermal device in an aircraft allows significantly reducing the maximal temperature at equipment using a light and passive thermal device. This leads to an increase of equipment’s reliability combined with a fuel consumption reduction.
This project has been performed in collaboration with Labinal Power System as topic manager.