A comprehensive CFD combustion model for supercritical CFB boilers--颗粒学报PARTICUOLOGY

Xu, L., Cheng, L., Ji, J., Wang, Q., & Fang, M. (2019). A comprehensive CFD combustion model for supercritical CFB boilers. Particuology, 43, 29-37. https://doi.org/10.1016/j.partic.2017.11.012

A comprehensive CFD combustion model for supercritical CFB boilers

Linjie Xu, Leming Cheng ^*, Jieqiang Ji, Qinhui Wang, Mengxiang Fang

Institute for Thermal Power Engineering, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China

10.1016/j.partic.2017.11.012

Volume 43, April 2019, Pages 29-37

Received 15 May 2017, Revised 8 November 2017, Accepted 11 November 2017, Available online 19 May 2018, Version of Record 19 February 2019.

E-mail: lemingc@zju.edu.cn

Highlights

• A 3D numerical combustion model for large-scale supercritical CFB boilers was developed.

• The model consists of gas–solids hydrodynamics, coal combustion, and heat transfer in furnace.

• Thermohydraulics in tubes was considered to couple the heat transfer processes.

Abstract

A combustion model of a large-scale supercritical circulating fluidized bed (CFB) boiler was developed for comprehensive computational-fluid-dynamics analysis. The model incorporates gas–solid hydrodynamics, coal combustion, heat transfer on heat exchange surfaces in the furnace, and heat transfer between furnace and working medium in the heat transfer tubes. In simulating the dense and dilute phases in the furnace, the gas–solid hydrodynamics is based on the Euler–Euler model and energy-minimization multiscale drag model. Coal combustion entails evaporation, devolatilization, char combustion, gas homogeneous reaction, and pollutant emission. The coefficient of heat transfer between gas–solid and the waterwall is estimated using the cluster renewal model, and for radiation, the discrete ordinate model is used. Moreover, thermohydraulic processes in the membrane wall are also included in the heat transfer process. The model was successfully applied in simulations of a 350-MW supercritical CFB boiler. Detailed distributions of solids concentration, oxygen, heat flux, and working medium temperature in the boiler furnace are presented.

Graphical abstract

Keywords

Comprehensive combustion model; Computational fluid dynamic; Thermal-hydraulics; Supercritical circulating fluidized bed; Large-scale furnace

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