Abstract
The aim of the paper is Computational Fluid Dynamics (CFD) analysis of Wall Heat Transfer Coefficient (WHTC) of pressurized pipe as a part of super-heater of the OP210 boiler. The object of the investigation is convection from saturated steam to the wall of the pipe, which works under high pressure and high temperature. The analysis is an approach to obtain exact solutions of WHTC according to the third type boundary condition compared to direct results from CFD analysis. The paper consists of three-step approach typical for CFD analysis: (i) Pre-Processing, the most elaborated part of the analysis where knowledge about super-heaters, turbulence, velocity profile is important to 3D model, mesh and boundary condition definition. (ii) Simulation of steady state turbulent flow until convergence criteria are met. (iii) Post-Processing where different approaches to the WHTC are shown in comparison. Also, the investigation includes two different types of meshes (where a different number of inflation layers are used) and comparison between k-epsilon and Solid Shear Stress (SST) turbulence model.
Highlights
Super-heaters are significant accessories of steam boilers in terms of Rankine’s cycle efficiency [1, 2]
In order to examine the value of the wall heat transfer coefficient determined by the Computational Fluid Dynamics (CFD)-Post, the definition of the wall heat transfer coefficient (WHTC) according to the third type boundary condition should be referred to [5, 7, 15]:
The bulk temperature reflects the average temperature of moving fluid in a particular cross section
Summary
Super-heaters are significant accessories of steam boilers in terms of Rankine’s cycle efficiency [1, 2]. As high as possible parameters of steam should be used. Dehumidification of the vapour is very important due to the erosion of turbine blades [2]. In all of these cases, super-heaters are used. There are two different types of super-heaters dependent on the mode of heat transfer. Convection and radiant superheaters, where heat transfer is almost dependent on the parameters of the gas flow in the first case and highly dependent on the flue gas temperature in consequence of combustion in the second one. Dimensions are related to the operating pressure and total capacity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
