Application of CFD simulation and VR visualization in industrial process
The petroleum refining and power industries involve many capital and energy intensive processes. Due to complex phenomena and the difficulties involved in taking direct measurements, the knowledge needed for process optimization can be most readily obtained through the development of high fidelity computational fluid dynamics (CFD) numerical simulations. CFD has become a powerful simulation technology used in industrial process design and optimization for productivity enhancement, energy efficiency optimization, environmental management, and quality assurance. With increasingly complex CFD capable of simulating and analyzing ever-larger amounts of data, interpolating and presenting the numerical data in a meaningful fashion is a key for effective communication between CFD experts and plant engineers. Traditionally, CFD experts frequently develop two-dimensional pictures and animate their results to help make the information easily digestible. Recently, virtual reality (VR) technology made it possible for people to analyze huge amounts of CFD data in a virtual environment. VR creates a computer-generated world in which people who are not analysis experts can see the results in a context that they can easily understand. Even people who are familiar with interpreting analysis results can gain insights that make it possible to understand the root causes of observed problems and plan design changes more rapidly than was previously possible. In the present study, several virtual engineering (VE) applications in the petroleum refining and power industries have been discussed. Although there are many sources of electrical power generation, more than 50% of total electricity output is produced by coal-fired power stations. High pressure steam produced through coal combustion turns multiple stage steam turbines connected to generators. Then, the exhaust gas generated by the combustion is discharged through air ducts and out to pollution control units before it's released to the atmosphere. The exhaust gas ducts at Bailey power station suffer from low efficiency, resulting in an inability of the plant to reach full load. This loss of capacity makes a significant impact on the overall energy production from the power station which can lead to a considerable loss of revenue. In this study, CFD has been employed to simulate the air duct operation. After visualizing the CFD results on the VR system, an optimized design of the air duct using turning vanes has been obtained from the CFD model. After the installation of the recommended turning vanes, all boilers are able to operate at designed capacity. ^ After that, the focus moves to the petroleum refining industry. The Gas-Oil Hydrotreater (GOHT) produces low-sulfur feed for downstream units. An oil and hydrogen mixture is delivered by a piping system to the hydrotreater furnace. Uneven splitting and/or phase separations of the original stream can cause uneven heating as well as high furnace tube metal temperature, which can lead to shorten tube life and may lead to tube rupture. In order to achieve better understanding of the current design, a three dimensional multiphase isothermal CFD model of a hydrotreater furnace inlet piping system has been developed to determine the oil and hydrogen flow region throughout the piping system and report the degree to which each flow split is uneven. The CFD model provides detailed velocity distributions and flow patterns together with the oil concentration and pressure drops at different location of the entire piping system. The degree of uneven splitting to all the outlets has also been evaluated quantitatively. The simulation results provide a thorough understanding of the operating performance, while the parametric studies offer insight into the optimization of the current piping design. ^ Lastly, a numerical simulation of a cooling tower basin used in refining industry has been developed. The formation of vortices at the suction area can deteriorate the pump efficiency thus diminishing the cooling tower capacity. To analyze the detailed flow characteristics in the suction bay areas in order to investigate the existing or potential vortex formation of the current design, two different CFD operating scenarios have been modeled, namely, all pumps active and one pump inactive based on the geometry of two cooling towers. In all projects, the VE environment has greatly enhanced the value of CFD simulations and allows engineers to gain much needed process insights in order to make sound engineering decisions.^
Chenn Qian Zhou, Purdue University.
Engineering, General|Engineering, Industrial