Combustion Engineering at the University of the Witwatersrand
Measurement and instrumentation equipment installed on key components in the full combustion systems is quite limited and sometimes inaccurate in existing plants. Additionally, control devices have drawbacks and inaccuracies, which complicate control of the operation set points of components and sometimes control of total boiler behaviour. It is, therefore, difficult to monitor the combustion system online for early detection and diagnosis of abnormal situations that cause unreliable and inefficient operation.
Local environmental standards require implementation of NOx reduction technology in all existing and new-build plants. The low-NOx burner operation requires accurate coal and air flow measurements for optimal control due to its operational limits and the variations in coal quality and the need for load shifting of Eskom plant.
An urgent need exists to improve measurement and online monitoring of:
- coal mass flow and coal quality, especially ash and moisture content;
- milling plant performance to control fuel/air ratios, particle size, and mass flows;
- air streams to wind boxes, burners, and air heaters;
- heat transfer from flue gases to the air and water-steam circuit.
The SC strives to improve understanding of local coal impact and predicting of the effects on coal-fired power plant. Research is focused on current Eskom requirements to:
- improve and grow a repository of skills and knowledge of existing plant;
- create skills and tools to design, operate, and maintain plants;
- ensure that future plants are cleaner, available, reliable, efficient, and safe (CARES);
- achieve world-class output in combustion engineering-related technologies;
- retain a highly skilled engineer base in Eskom to create a healthy fleet for current and future power generation using state-of-the-art technology;
- host the combustion system design intellectual property purchased by Eskom;
- attract local manufacturers to build and supply burners for the local market;
- provide a continuously improved bouquet of experimental facilities in heat transfer, combustion technology, and thermodynamics.
To achieve its goals, the SC embarks on an applied research method ranging from fundamental research to pilot-scale and full-scale testing, which is then taken to implementation and further development, as outlined in the research flow chart.