The U.S. Department of Energy awarded UCF mechanical and aerospace engineering assistant professor Subith Vasu $1.1 million to investigate using supercritical CO2 (sCO2), a fluid state of carbon dioxide, instead of steam in power plants.
Graduate researcher Owen Pryor, 25, said that there were nine projects in total and both Georgia Tech, the only other university awarded in the nation, wrote proposals on sCO2 although both universities are performing different projects.
Pryor said that supercritical steam is used in nuclear power plants but is being looked into being replaced since it is both corrosive and hard to compress. The theoretical idea is that with CO2 it would only take four stages to compress versus 55 it takes steam to compress.
“We use a shock wave to compress chemicals and then, in fuels for examples, if you do this right, their temperature and pressure high enough, then they start to break down and turn into different chemicals and basically you get ignition like fire and combustion. It’s all just chemical reactions so we use this to study chemical reactions,” explained 22-year-old graduate researcher, Joseph Lopez about how shock tubes work.
The shock waves sent through the tube are like a single piston stroke compressing the chemicals. With the information they collect from different chemical reactions, they record concentrations over time of different species. Pryor said the mechanism they are creating will simulate the chemical reactions that occur using two species and ignition delay times to validate the mechanism.
“The goal by the end of the project is to have a validated chemical kinetic mechanism that can be implemented in an open source CFD code. A chemical kinetic mechanism is a tool that allows people to simulate the reactions to help understand what is produced during combustion, temperatures and pressures,” Pryor explained. “The mechanism will then be added to a computer code to simulate the sCO2 combustor. Possible preliminary designs of combustors will be created.
Vasu said they aim to help industries develop technologies to use CO2 as a working fluid which can be stored underground and enable using less water which is scarce in certain areas of the nation. Florida is a leading state when it comes to power generation industry and many major gas turbine companies, including Mitsubishi and Siemens. The gas turbine companies work with UCF’s Center for Advanced Turbomachinery and Energy Research (CATER) which is headed by Prof. Jayanta Kapat from the Mechanical and Aerospace Engineering Department. Prof. Vasu is a core member of CATER.
The project will take three years to perform in continuation with other projects being performed in Vasu labs.
The $1.1 Million grant covers costs such as paying for graduate students working on the project but does not pay for permanent improvements such as new facilities or buildings.