CERAMIC
COMPOSITE – SCI & TECH
News:
Efficient passive
radiative cooling materials developed
What's
in the news?
●
Researchers conceived a composite of ceramic zirconium carbide and
tungsten, to create robust heat exchangers for conversion of solar heat to
electricity.
●
By creating plates of the ceramic-metal
composite, they were able to get better performance at higher temperatures.
Key
takeaways:
How
does it work?
●
Concentrated solar power plants convert solar energy into electricity by
using mirrors or lenses to concentrate a lot of light onto a small area,
which generates heat that is transferred to a molten salt.
●
Heat from the molten salt is then
transferred to a “working” fluid, supercritical carbon dioxide, that expands
and works to spin a turbine for generating electricity.
●
To make solar-powered electricity cheaper,
the turbine engine would need to generate even more electricity for the same
amount of heat, which means the engine needs to run hotter.
●
The problem is that heat exchangers, which
transfer heat from the hot molten salt to the working fluid, are currently made
of stainless steel or nickel-based alloys that get too soft at the desired
higher temperatures and at the elevated pressure of supercritical carbon
dioxide.
●
Researchers conceived a composite of ceramic zirconium carbide and
the metal tungsten for more robust heat exchangers.
●
They created plates of the ceramic-metal
composite.
●
The plates host customisable channels for
tailoring the exchange of heat.
●
Mechanical tests and corrosion tests
showed that the composite material could be tailored to successfully withstand
the higher temperature, high-pressure supercritical carbon dioxide needed for
generating electricity more efficiently than today’s heat exchangers.