Investigation of gas‒solids flow hydrodynamics in a cold model of a dual fluidised bed gasifier using electrical capacitance tomography sensors--颗粒学报PARTICUOLOGY

Luo, Z., Lin, Y., Tu, Q., Yang, W., & Wang, H. (2020). Investigation of gas‒solids flow hydrodynamics in a cold model of a dual fluidised bed gasifier using electrical capacitance tomography sensors. Particuology, 51, 193-204. https://doi.org/10.1016/j.partic.2019.11.003

Investigation of gas‒solids flow hydrodynamics in a cold model of a dual fluidised bed gasifier using electrical capacitance tomography sensors

Zhan Luo ^{a b}, Yonglei Lin ^{a b}, Qiuya Tu ^a, Wuqiang Yang ^c, Haigang Wang ^{a b *}

a Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
b University of Chinese Academy of Sciences, Beijing 100049, China
c Department of Electrical and Electronic Engineering, University of Manchester, Manchester, M13 9PL, UK

10.1016/j.partic.2019.11.003

Volume 51, August 2020, Pages 193-204

Received 25 August 2019, Revised 17 November 2019, Accepted 21 November 2019, Available online 25 December 2019, Version of Record 11 April 2020.

E-mail: wanghaigang@iet.cn

Highlights

• DFBG with upper and lower U-valves was built for coal/biomass gasification.

• ECT was first used to investigate the gas‒solids flow in the DFBG.

• Defluidisation in the reactors was detected by ECT and pressure signals.

• UBFB was identified as a substantial influence on the balance of the DFBG.

Abstract

The flow characteristics of a dual fluidised bed gasifier (DFBG) are more complex than those of a single fluidised bed gasifier. For stable operation and appropriate control, a cold DFBG test facility with both an upper and a lower U-valve was built, and electrical capacitance tomography (ECT) sensors were installed with pressure transducers to investigate the effects of operating conditions on gas‒solids flow hydrodynamics. The operating parameters included gas velocities in the riser and in the bubbling fluidised bed, aeration velocity in the lower U-valve, bed material inventory, and particle size. This is the first time that ECT was applied in different flow zones of a dual fluidised bed gasifier system. The experimental results indicated that ECT in the recycle chamber could monitor the performance of the lower U-valve under different operating conditions for early detection of gas shortcut from the riser to the bubbling bed. Three main flow regimes in the riser and the differences between the reactors were identified by two sets of ECT sensors with pressure transducers. Finally, the effects of the operating conditions on the pressure drop in different parts of the DFBG was investigated.

Graphical abstract

Keywords

Dual fluidised bed gasifier; Hydrodynamics; Electrical capacitance tomography; Flow regime identification

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