The availability and properties of materials of construction are a limiting factor in practically every direction of development in the technology for the power sector. In the case of sCO2 cycles, the demands on materials are high, primarily due to high pressures and temperatures, which create a highly corrosive environment.
The existing infrastructure, or the infrastructure currently under-construction, at the Řež research centre can be used to test materials in an environment that corresponds to the real world operation of sCO2 cycles. The autoclave used for corrosion tests operates at up 850 °C and 25 MPa and can be operated at relatively low cost with a high number of test samples of different materials. Material tests can also be performed using the SUSEN sCO2 loop, where in addition to supercritical parameters (up to 550 °C and 25 MPa), high flow rates can also be achieved.
The competitive advantage of Řež Research Centre is not only that it is possible to use unique equipment to test under supercritical conditions, but also the availability of modern infrastructure that allows an evaluation of the properties of materials. This includes, for example, optical or electron microscopes for evaluating the structure of samples post exposure in the test system and a range of equipment for mechanical tests. An extensive test campaign was carried out as part of the sCO2-FLEX project, where more than 80 samples of different materials were tested under conditions that corresponding to supercritical CO2 cycles. In addition to high temperatures and high pressures, some of the samples were also exposed to high sCO2 flow rates (above 100 m/s) in order to simulate the conditions that might exist on the blades of rotating machines.
