To improve the efficiency and environmental performance of fossil fuel–based energy production, researchers at the National Energy Technology Laboratory (NETL) have developed high-speed imaging systems—comprising both video and accompanying software—that allow researchers to see and analyze particle motion in great detail, deep inside fast-moving flow fields.
Fossil fuel energy systems are filled with particles of coal, ash, or catalyst smaller than a grain of salt. Blizzards of these particles are carried through the systems at high velocities by air or other gases. Following the paths of individual particles as they zip through a system is nearly impossible. The air field’s harsh, opaque nature makes seeing particles and measuring the flow fields difficult. Catching these particles on high-speed video allows researchers to track the particles’ movements, which helps inform the development of more effective energy systems.
An example is NETL’s use of a high-speed imaging system to develop a multiphase flow challenge problem for the computational fluid dynamics modeling community. This was done as part of the laboratory’s efforts to improve gasification technologies, which break coal down into its basic chemical constituents to generate power, chemicals, hydrogen, and transportation fuels, while facilitating the capture of CO2 for sequestration or enhanced oil recovery. Research teams from five different countries submitted results to help benchmark current state-of-the-art modeling techniques. The challenge problem enabled the research community to compare multiphase models with a common set of validation data produced by NETL. The knowledge gained will help accelerate the development of accurate computational models of multiphase flows.
The benefits of NETL’s imaging systems extend far beyond energy production. Because of their versatility, these systems have been used by doctors to track blood flow and improve outcomes for cardiac patients and by engineers to seal the Deepwater Horizon oil spill.
Faced with clotting problems in artificial hearts, cardiac transplant surgeons at Presbyterian Hospital in Pittsburgh, Pa., and Baxter Healthcare (Deerfield, Ill.) turned to NETL for help. Baxter’s left ventricular assist device (LVAD) was developing areas of stagnant flow that caused blood clots, which could eventually dislodge and cause strokes, and they couldn’t figure out why.
NETL researchers modified their high-speed video and software to see and measure blood flowing through the artificial heart. Blood cells flow much like particles do in energy systems. The video made it easier to track tiny, individual particles within flowing blood, allowing researchers to determine the cause of stagnation in the artificial organ. The data allowed bioengineers to successfully modify the LVAD to stop the production of blood clots. The data was also used to improve the design of other cardiac devices, such as the Nimbus AxiPump and the Hattler Intravenous Membrane Oxygenator. The collaboration among NETL, Baxter, and Presbyterian Hospital led to an R&D 100 Award in 1992 when the editors of R&D magazine deemed NETL’s "Fluorescent Image Tracking Velocimetry System" one of the 100 most technologically significant products introduced into the marketplace over the past year.
Because many natural systems have similar patterns of movement, NETL’s high-speed video technique was modified in 2010 for yet another purpose: to determine how much oil was leaking from the Deepwater Horizon disaster. Using video of the leak taken by small submarines, an NETL-led group of engineers and scientists produced the first accurate government estimate of the oil leak rate from the well. This estimate helped to improve the level of response, and it was used by engineers to design a system to permanently cap the well. For this effort, the Director of the U.S. Geological Survey presented the team with an award for Exemplary Service to the Nation.
This storm of successes for NETL’s high-speed imaging technology shows no sign of stopping. NETL’s future plans include using the technology for visualization of carbon-capture processes using amines to help reduce carbon emissions and mitigate climate change.
This month, NETL and many other of the Energy Department’s national labs are showcasing their contributions to "The Science of the Very Fast and Very Small." For more information, please visit the Energy Department’s national lab webpage.