| Author: | Chan, Hing-mou |
| Title: | The relationship between a coal firing power plant emission and its operating factors |
| Degree: | M.Sc. |
| Year: | 1999 |
| Subject: | Coal-fired power plants -- China -- Hong Kong Coal-fired power plants -- Fume control -- China -- Hong Kong Coal-fired power plants -- Environmental aspects -- China -- Hong Kong Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Civil and Structural Engineering |
| Pages: | xiv, 113, [37] leaves : ill. ; 31 cm |
| Language: | English |
| Abstract: | As coal is considered to be a relatively dirty fuel compared with natural gas or nuclear, the emissions and factors that affect the emission from a coal firing power plant are attracting more concern due to the ever tightening licence limits imposed by the government. Increasing the energy efficiency extends the capability of a coal firing power plant to meet economic and environmental requirements. The close relationship between environmental emission and energy efficiency indicates that emission reduction by means of better fuel utilization or efficiency improvement is worth studying. Due to the complexity of a modern power plant, there exists complex relationship between the plant emissions and its operating conditions. An integrated study of the correlation between emissions and various emission related factors throughout the "coal-to-electricity" chain was carried out. This study aimed at identifying the relationship between emissions and the prevailing operating conditions or external factors in a coal firing power plant. Whenever possible, methodology was developed to quantify the relationship between these emissions and operating factors for the power plant studied. The mathematical relationships developed for a typical coal firing power unit or the whole power plant can assist in the formulation of a model applicable in the prediction of emission variation due to variation in internal/external or controllable/uncontrollable factors. The scope of this study confined to air emissions (CO2, SO2, NOx, Particulate and Trace element) of a regional power plant. This study was divided into five parts. The first part related to the impact of the principle factors that govern the emissions from a regional power station-the local electricity demand and the current role of coal in power generation in Hong Kong. Analysis of global and local trend indicated that economic and technological reasons support the continuous using of coal for power generation. Identification of all the relevance source of emissions in a power station and the analysis of emission reduction due to implementation of more advanced emission control technologies was also included. In the second part, properties of coal burnt were correlated to the emissions. Dependence of emissions on coal moisture, sulphur, volatile matter, ash, nitrogen and carbon were investigated. The third and forth part investigated the impact of operating conditions and equipment performance on the plant emissions. It was found that factors like steam condition, although important to the energy efficiency of a steam power cycle, are making only minor contribution to plant emission. Operating factors in boiler side like excess air level, flue gas temperature and fuel air ratio are more influential to NOx, particulate and unburnt carbon emission. Among the emissions, particulate is the one most sensitive to operational factor's impact while NOx is most combustion environment dependent. The last part of this study investigated how those external factors which are out of the scope of control of the plant operators are affecting the emissions of the power station. Sea water temperature and system load both affect emission through the third (energy efficiency pathway). Growth in system load results in increase in load share on generating unit with better pollution control measure, thus making the particulate, NOx and SO2 emission variation more sensitive to the emission from old units. The complicated inter-relationships between operating factors of a coal firing power plant and its emission together with the continuous implementation of new technology necessitates the continuous investigation on more indicative parameters and their correlation with the emission. |
| Rights: | All rights reserved |
| Access: | restricted access |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| b14605016.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 7.13 MB | Adobe PDF | View/Open |
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