Chalk up another substantial cost savings for a Northwest Indiana industry, thanks to assistance provided by Purdue University Calumet mechanical engineering students through the university’s Center for Innovation through Visualization and Simulation (CIVS).
NIPSCO officials project an annual savings of some $1.9 million at the company’s Bailly Generating Station in Chesterton after efficiency of the Unit 8 boiler was improved, restoring its maximum operating capacity.
The problem surfaced last year when NIPSCO engineers discovered that the Bailly boiler exhaust air ducts, through which exhaust gas from coal combustion is discharged to pollution control units, were operating at just 85 to 90 percent of maximum capacity. The reduced operating capacity diminishes overall energy production—and revenue.
“After completing the installation of pollution control equipment on our smaller Unit 7, we found that we could no longer get full flow or load through the larger Unit 8,” Bailly Station Engineering Supervisor Tim Wright said. “We experienced what’s considered a derate of roughly 20 megawatts out of the 320 net megawatts of capacity.”
So NIPSCO Bailly partnered with Purdue Calumet to help troubleshoot the problem. The university employed computational fluid dynamics and virtual reality visualization technologies within the university’s CIVS facility. CIVS is a research center that combines advanced simulation and 3-D visualization technologies to provide innovative, timely and cost-effective solutions for real world problems.
Using CIVS technology, Purdue Calumet students, faculty and staff worked with NIPSCO engineers to study and analyze the flue gas ducts of Bailly boilers 7 and 8. Flow restrictions were identified, and an optimized design of the exhaust duct using multiple turning vanes was generated and installed.
Subsequently, plant officials have observed significant flow efficiency improvement from the Unit 8 boiler and claim it is now operating at full capacity.
“The CFD (computational fluid dynamics) study initially conducted by the students showed recirculation in the duct downstream of the ‘Y’ where the output of the two units are combined,” Wright said. “Further CFD study resulted in an optimized arrangement of turning vanes, thereby improving flow in the ducts. When the vanes were installed, the derate went away. Using rather rough estimates, the result is an estimated $1.9 million in annual savings if the unit continues to operate in this manner.”
CIVS Director and Purdue Calumet Professor of Mechanical Engineering Chenn Zhou called the outcome “a win-win situation and an excellent example of the unique ability of CIVS to partner with industry to solve real world problems. The close interaction with industrial partners also creates great experiential learning opportunities for our students.”