NIPSCO challenge provides ‘reality’ learning moment for students

By Erika Rose, a freelance writer

About the time Purdue University Calumet introduced its Center for Innovation through Visualization and Simulation (CIVS), an operational issue happened to arise at Northern Indiana Public Service Company’s (NIPSCO) Bailly Generating Station.

The issue presented challenges that plant engineers felt required the assistance of a resource not readily available to them: computational fluid dynamics (CFD). CFD is a relatively new and notably more cost- and time-effective method of analyzing problems with fluid flows.

According to Kurt Sangster, manager of maintenance and engineering at NIPSCO’s Bailly Generating Station, physical flow modeling would have been expensive to undertake, and the plant does not have the capability to run CFD simulations.  But Purdue Calumet’s new Center for Innovation through Visualization and Simulation does.

“We have two generating units at the facility that are coal-fired boilers,” Sangster explained. “The gas exits the boilers and comes together in a common duct. It flows together and goes through a pollution control device where the pollutant sulfur dioxide is removed. Right before the two come together, they were experiencing some back pressure problems. We weren’t getting all the flow out of the units that we could gas-wise, because they were just not interacting as they were originally designed.”

When NIPSCO engineers asked Zhou and her team of faculty and student engineering researchers to develop a solution to bring both units up to full load, the PUC team went to work in the CIVS facility, a virtual reality laboratory of sorts.  Using physical measurements of the equipment provided by NIPSCO, the students created a computer model. Their resulting simulations showed two gas flows coming together. While one flowed perfectly the other offered a chaotic and disruptive flow. Further simulation showed insufficient exhaust at the output duct, a potentially serious problem that otherwise likely would not have been detected.

Taking CFD a step further, the Purdue Calumet team brought NIPSCO engineers into the CIVS to interact inside a virtual boiler unit to create a picture from the numbers the simulation had created.  Before CFD, plant engineers would use a physical model constructed about 1/12 to 1/20 of the size of the real equipment to address such issues.  “You would actually run air through the model and drop in particles to see how it operated,” Sangster said, “but that only shows you how flows work in normal air. CFD, on the other hand, takes into account all those other factors that a normal physical model cannot, such as temperatures and factors that impact the air flow. Additionally, CFD allows you to adjust any particular aspect by programming it; you can get a different look each time. It’s simply more time consuming to conduct the same simple test on a physical model.”

Applying CFD within the Center for Innovation through Visualization and Simulation, the student team proposed installing turning veins – that is, large pieces of steel in the ductwork to ensure the flow is straight and does not come back on itself.

The modification recently was installed.