Advances in New and Renewable Energy >
Numerical Simulation of Ash Deposition on Wall of Fourth-Stage Superheater Pipes
Received date: 2017-02-18
Revised date: 2017-04-11
Online published: 2017-06-30
For the fourth stage superheater at the outlet of a 12 MW biomass-fired power plant, an ash particle deposition model considering the condensation of gaseous alkali metal salts and rebound/stick of ash particles was developed by considering of the inertial force, Brownian force and thermophoretic force. The effects of tube arrangement and KCl content in ash particles on ash deposition characteristics were investigated based on a mathematical model. Results showed that the ash deposited mass on tube surface for each row was sharply increased with the KCl content increased; as the KCl content increased from 15% to 25%, and the deposited mass on the windward side of the first row increased from 4.82 × 10−7 kg/m2 to 4.03 × 10−6 kg/m2. The deposits on tube wall of each row were increased when the longitudinal pitch varied from 1.5D to 2.5D. The formation of irregular depositing characteristic around the tube was mainly attributed to the scouring position variation for upstream flue gas to downstream of the tube bundle, and the generation and shedding position of vortex.
Key words： superheater; ash particle; deposition; condensation; salt vapor
WANG Yi-bin1 , TAN Hou-zhang1 , LIU He-xin1 , XU Wei-gang1 , CAO Rui-jie2 . Numerical Simulation of Ash Deposition on Wall of Fourth-Stage Superheater Pipes[J]. Advances in New and Renewable Energy, 2017 , 5(3) : 163 -169 . DOI: 10.3969/j.issn.2095-560X.2017.03.001
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