Abstract
Boiler tube leaks are one aspect that is commonly affecting the production of megawatts produced in power stations. Specifically thermal mechanical fatigue failure has been a very stressful and repetitive failure mechanism within many fossils power stations. This failure mechanism is usually caused and affected by the type of material used on the tubes. Understanding the various temperatures used in different tubes and components is highly significant. This assist by giving a much better focus on installing using the correct material on the tube for the required component.
This research study found that the method by which the boiler was turned on and off each time was the primary cause of the mechanism failure. This is crucial because, once the boiler is operating, it must not accelerate its lightening rate too quickly as this could put the boiler's material under unnecessarily high strain from sudden, uneven temperature increases. It was discovered that in order to lower the lightening up rate, multiple start/stop sequences must be executed during unit light up. In addition, boilers are classified based on the maximum operating temperature and pressure for which they are designed. Classifications, in ascending order, are subcritical, supercritical, ultra-supercritical, and to advanced ultra-supercritical. At each higher operating point comes greater efficiency, as well as greater chance of experiencing TMF failure. The research study investigated the correct mechanism solution for one of the failure mechanisms, (Thermal Mechanical Fatigue) inside the boiler. It was found that Thermal Mechanical Fatigue failure mechanism is one of the failures that occurs from occurrence of high temperature, imbalance of boiler feeding to the tubes. It was also observed that operators running the boiler from the control room can impact in occurrence of Thermal Mechanical Fatigue failures, Creep failure and Soot Blowing failures. This is because preventing this failures requires operators who are highly trained and are reminded to appreciate their responsibilities. It was concluded and recommended that operators should go to trainings every 2 months. This would assist and help them to be reminded of their critical role towards providing efficient boiler performance.
KEYWORDS: Tube leaks, Thermal Mechanical Fatigue Failure, Boilers, Thermal Temperatures, Thermal Stresses, and Fossil Power Station.