Pulsating heat pipe case study

The European Space Agency partnered with the European design engineering team of Eaton, for its INWIP project: innovative wickless heat pipe systems. The purpose of the project was to study the behaviour of a wickless pulsating heat pipe system in micro-gravity conditions. The extreme conditions and complexity of the technology.

The project was divided into two parts:

REXUS: A pulsating heat pipe system surrounded by metal foam and inserted into a metal box filled with paraffin wax. The heat, carried by the vapour bullets, flows into the metal foam, melting the paraffin wax.

ISS: A pulsating heat pipe system connected to 8 Peltier cells. The heat carried by the vapour bullets warms one side of the Peltier cells and a liquid cold plate cools the other side.

In cooperation with the University of Pisa, Eaton designed and manufactured the prototypes for both parts of the project.

ROCKET REXUS 22: In March 2017, the prototype was launched from the Esrange Space Center in Kiruna, North Sweden, aboard the rocket Rexus 22, to be tested in zero gravity. The rocket followed a parabolic trajectory up to an altitude of 90 km and fell to the ground.

ISS ZERO-GRAVITY PARABOLIC FLIGHT: The cooling system will be installed on a plane which will run along 32 parabolas on a future test flight. In correspondence to the peak of each parabola, the force of gravity will be balanced by vertical traction, creating a transient state of 22 seconds of micro-gravity. During this time, we will be able to monitor the behaviour of the pulsating heat pipe.

A goal of this research is to properly prepare for systematic experimentation on the Thermal Platform 1 (TP1) aboard the International Space Station and to investigate the performances of cooling systems with ordinary and innovative working fluids.