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Title: The reduction of emissions from coal fired boilers
Author: Jewell, E. H.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1994
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This thesis reports the results of numerical and experimental investigations into the flow in coal fired power station boilers with particular attention being paid to the reduction of NOx and SOx through the use of reburn and sorbent injection. Isothermal and combustion numerical models were created in the computation fluid software package FLUENT for both front fired and corner fired boilers. The isothermal models were created so that experimental and literature comparisons could be carried out to assess the quality of the flow predictions by numerical models and to identify key solution parameters. The combustion models were created so that modelling of the parameters controlling the effectiveness of reburn and sorbent injection, for NOx and SOx reduction respectively, could be investigated. An isothermal 1/20th scale model of Rugeley B front fired boiler was constructed in order to compare the measured and predicted flow at flow rates from 0.78 m3s-1 to 3 m3s-1. The velocity was measured using a single component back scatter laser Doppler anemometry system. The signal processing was carried out using photon correlation with custom written PC based software and atomised water was used as seeding. Further validation of the numerical models was sought through isothermal experimental simulations of the reburn and sorbent injection process through the addition of jet inlet to the experimental apparatus. The experimental observations showed that, while generally the agreement between the predicted and measured flow fields was good, the k-ε turbulence model has a considerable damping influence on the flow leading to a substantial over prediction of secondary flows which can produce discrepancies close to low velocity jets. The coal combustion model incorporated in FLUENT over predicts the char combustion rate with typical bituminous coal.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available