Modeling Fluid Flows and Heat Transfer in Industrial Processes Using Gothic Software

摘要

Energy conservation measures in manufacturing plants and commercial facilities often involve modifications to convective processes. Examples of equipment used to carry out these processes include heating, ventilating, and air-conditioning equipment, refrigeration equipment, dust collection systems, drying and curing ovens, kilns, and melting cupolas. Because requirements and operating conditions change over time, there is often a need to modify existing equipment. The potential for energy savings may be very large, but engineers and plant managers are still reluctant to take action because it is not easy to predict the overall effects of proposed changes in such complex systems. Computer assisted analyses are needed in many cases. GOTHIC is a general purpose thermal hydraulics code originally developed for design, licensing, safety, and operating analyses of nuclear power plant containments and other confinement buildings. It is a state-of-the-art program that solves conservation equations for mass, momentum, and energy for multi-component, multi-phase flows. The code is user-friendly, and is capable of modeling systems with many components. This work employs GOTHIC to evaluate proposed changes to a forced convection system for cooling urethane foam logs. The logs, which are about 30 ft′ in cross section by 200 ft in length, form when liquid chemicals react on an enclosed conveyor. The exothermic reaction continues for a few hours after the log is formed. As many as 24 logs are stored in racks at one time and cooled by refrigerated air. A ventilation system removes fumes from the storage area. The system is inefficient and costly to operate because the cooling airflow pattern is not optimized, and because cool air is removed by the ventilation system. The GOTHIC code makes it possible to easily and quickly predict flows and air temperatures in the complex geometry, transient temperatures within the logs, and to optimize the cooling system.