Excerpt from article published in the Union Gas, Gasworks Publication
By Neil Macfadyen, Strategic Industrial Markets Project Manager
A quick and economical way to solve industrial problems is Computational Fluid Dynamics (CFD), which has become widely accepted in many industries. In CFD modeling, a three-dimensional (3D) computer ‘model’ of process equipment, such as a boiler or furnace, is built from digital drawings of the plant, and the process is simulated using fundamental equations for fluid flow, combustion and heat transfer. CFD, with the addition of three-dimensional virtual reality (VR), brings process understanding to a much higher level. Once the CFD model run has been completed, the engineer can step inside the process and really ‘see’ what is going on. At Purdue University Calumet (Hammond, IN), a new facility is combining CFD and other simulation technologies with VR, providing companies with faster and more cost-effective solutions to a myriad of problems.
The Center for Innovation through Visualization and Simulation (CIVS) was established in 2009. In the fall of 2011, it opened its new facility that includes several state-of-the-art laboratories. The 70-seat, Immersive Theater features a large-scale 3D VR system called the Flex, which uses an optical tracking system and four projection screens to allow users to interact with virtual environments. For example, an engineer optimizing burner flame length in a model of a furnace could have the impression that they are inside the furnace, looking at the burner, and could reach out and ‘sample’ the temperature and combustion gas composition at a point. The Visualization Lab combines a two-screen immersive projection system, high-end workstations, and specialized graphics software for the development of virtual reality and other 3D visualization projects.
CIVS research provides practical information and data that can be used in many industries, including manufacturing, energy, healthcare, construction and transportation, to name a few. Over 150 students have worked on more than 124 CIVS projects, resulting in savings of over $30 million for companies.
Optimizing blast furnace operations
CFD simulation is a powerful technology for improving the operation of blast furnaces in the areas of energy efficiency, productivity, campaign life and fuel utilization. Over the past six years, Union Gas, as a member of a blast furnace consortium at Purdue Calumet, has collaborated with its integrated steel customers to maximize the benefits of co-injection of natural gas and pulverized coal into blast furnaces using CFD. Collaborations of this type led to the establishment of CIVS.
The blast furnace consortium was funded by the U.S. Department of Energy through the American Iron & Steel Institute (AISI). The partners were three major steel companies and Union Gas. The natural gas injection project was part of this consortium, which developed a three-dimensional model of the entire blast furnace.
The blast furnace model consists of two parts. The first part looks at the region near the bottom of the furnace where the preheated oxygen-enriched blast air and the injected fuels enter the furnace through copper nozzles located around the lower part of the furnace. The upper half of the overall model, called the shaft simulator, can be operated separately, but can also be connected to the output of the first model.
The shaft simulator models the flow of hot gases up through the furnace shaft, as well as the preheating of the ore, coke and fluxes that are being charged at the top of the furnace, otherwise known as the burden. Depending on the gas flow patterns and temperatures, the model calculates the impact on iron reduction in the shaft and ensures that all energy is accounted for in the model.
“The creation of the shaft simulator has been an enormous challenge, but I believe the key components that have been developed are already shedding new light on what affects blast furnace fuel rate,” says Neil Macfadyen, Strategic Industrial Markets Project Manager at Union Gas.
The blast furnace model—which predicts velocity, temperature, pressure, combustion reaction, particle trajectories, volatile matter evolution from the particles and the particles’ ensuing burnout—helped U.S. Steel Canada determine why its fuel-injection system failed frequently. To identify simulation results, advanced VR visualization technology was developed.
The CIVS technology generated detailed gas flow-stream data that previously had been difficult to measure because of the extreme operational conditions. That data revealed a 10 per cent increase in the coal devolatilization rate. This project on the pulverized coal injection in a blast furnace made “a real paradigm change in operating philosophy with the former Stelco management team in 2007 and with this process change realized a coke savings of 15 lbs/NT hot metal that resulted in a yearly potential cost avoidance of $8.5 million at full production using today’s spot market price for purchased coke,” according to John D’Alessio, Manager, Blast Furnace Engineering & Technology, U. S. Steel Canada.
The blast furnace consortium work was recently completed and included the creation of a virtual blast furnace for training. Says Macfadyen, “As a training tool for operating blast furnaces, 3D visualization is very powerful and will remove some of the rules of thumb that have dominated blast furnace practice for decades.”
The consortium research resulted in over $20 million in savings and avoided costs for its members; developed guidelines for design, optimization, and troubleshooting; and created CFD and VR software packages. A video of the blast furnace simulations can be viewed on the website.
Solving more problems
ArcelorMittal, another steel manufacturer, came to Purdue Calumet to help solve a number of industrial problems. These included: optimizing blast furnace fuel utilization and campaign life; increasing energy efficiency of the billet reheat furnace; and improving uniformity of strip heating.
“In each case CFD simulation allowed us to gain valuable insight into the complex heat transfer and fluid flow phenomenon that occur in these processes, leading to significant process improvements,” says Richard Sussman, ArcelorMittal’s General Manager for Global R&D East Chicago. “The Center’s new 3D visualization capabilities now bring process understanding and speed of solutions to an even higher level.”
ArcelorMittal also discovered that process development time could be shrunk in half or more by using such technologies. “CIVS has changed the way processes are developed,” says Sussman. “You can eliminate physical models and development steps.”
Advanced simulation and 3D VR can also help avoid costly mistakes. Lazar Anode Technologies LLC, a manufacturer of anodes for aluminum smelting, took advantage of CIVS’ three-dimensional technologies to model a furnace Lazar was building for manufacturing carbon anodes. Results showed a redesign was required so construction was halted until the design was finalized. “We learned that the thermal flows were different than what was previously believed,” says Michael Snyder, Project Manager for Lazar Anode.
Education for the Real World
With its emphasis on practical applications, CIVS is also playing a major role in developing the future workforce. Students gain real world experience and thus graduates are in high demand. Says Chenn Q. Zhou, Director of CIVS, “The virtual worlds being created at the Center will propel our student’s knowledge and understanding of their coursework, thus allowing practical application of their studies.”