CFD investigation of flow in tangential fired boiler

• Main Author: Premjit Singh A / l Hardeep Singh
• Published: 2023
• Subjects: Tangential fired boiler; Computational Fluid Dynamics; Burner tilt angle; Residual swirl imbalance; Temperature deviation

In this study, an actual design of a power plant’s subcritical boiler of TNB Janamanjung Power Facility of 700MW was used to investigate the effects of burner tilt angle on the swirl formation of air in the boiler which then causes temperature deviation on the upper part of the boiler. The study only includes investigation independent of combustion taking place in the boiler. CFD simulations have been carried out to study the effects of burner tilt angle to the swirl flow formation. The results obtained are used to compare between the burner tilt angle and the symmetrical air flow in the boiler. To achieve this, a full boiler design is modelled in ANSYS FLUENT 19.2 software. The model investigated is considered turbulent therefore realizable k-Epsilon was enabled in the settings. Boundary conditions of air and fuel inlet are set at constant while the vertical tilt angle of the burner is manipulated throughout the project to investigate its impact on the flow field of air in the boiler. The entire simulations were done in this software to assist with the investigation. The goal is to determine the root cause of flow field deviation in the upper furnace of a tangential fired boiler without combustion taking place. As a result, the figures and graphs obtained are used to justify the occurrence of swirl flow behavior in the boiler. The data obtained were compared and contrasted to understand the flow field deviation and the best possible angle needed to achieve the minimum deviation of air flow in the boiler. It is found that different vertical angles of burner inlet firing can cause a major change in the boiler’s fluid flow patterns at the upper furnace.