Micro Evaporators

The use of micro evaporation for cooling electronic components on small satellites is very promising because of its great potential on heat transferring capacity and its low mass flow. Due to the size reduction, the energy density increases in a lot of applications in space industry. On top of this, the thermal specifications on micro devices are often more tight than in macroscopic applications. Therefore, a proper design is essential for devices to be capable of dealing with associated high heat fluxes. Using evaporation high heat fluxes can be obtained. However, a good understanding of the heat transfer and evaporation on micro scales is necessary since some physical phenomena become more (or less) important. The PhD research performed at TNO TPD (in collaboration with the Delft university of technology) leads to insight on the behaviour of two phase liquid- gas flow in micro channels. The knowledge on both the heat transfer and the two phase flow patterns can be used to formulate relationships which can be used to design micro fluidic systems. Since gravity plays a minor role on micro scales these engineering tools will be appropriate for designing space systems as well.