Boiler Control Improving Efficiency of Boiler Systems

Abstract: This master thesis is written at the division of Industrial Electrical Engineering and Automation (IEA) Lund University, Faculty of Engineering, in cooperation with AB Regin in Landskrona. AB Regin wishes to determine whether their existing controller platforms can be used to implement a control system for boilers. The control system should be flexible in terms of boiler size, boiler fuel and boiler type. The main aspects associated with the combustion process are reviewed, and different types of fuel commonly used in boilers are investigated and compared. The most common boiler designs are described, and definitions used in boiler context are explained. To establish what techniques have been developed to improve boiler efficiency an empirical study is performed. The different techniques are discussed in detail, involving both control systems and design changes. Finally the measurement instruments involved in these improvement techniques are described. Case studies are performed to find out which techniques are used in practice to improve efficiency of boiler systems. To get a good idea of common techniques,the cases include establishments that use different fuels, and range from small scale to large scale. An effort is made to implement a boiler controller on the EXOcompact platform from AB Regin. A control algorithm is outlined and implemented for a fictional system. The system is then simulated using a demo kit from Regin. Some tests are performed to verify that the function of the control system is acceptable, and the results are discussed. Finally the overall thesis is discussed, and issues that should be addressed in future development are listed and explained.