Analysis of Tube Failure in Economizer and Super Heater Tube in Thermal Power Station

Boiler tube failure continues to be the leading cause for forced outages in fossil fired boiler. The tube failure may be a simple problem, unless it causes damage to the power plant and affects safety of the human being. The problem due to tube failure is realized only when the cost due to failure estimated. The main objective of our project is to reduce the number of tube failures occurring in boiler accessories at thermal power station by analyzing the reason behind the tube failure and provide suitable remedies for it. Tube failures in boiler accessories occur due to various reasons and major reasons for failure among the various reasons are flue gas erosion, long term overheating and steam erosion. The major failure reasons are taken from the tube failure. Major causes for failure can be controlled by using following remedies such as optimization of flue gas velocity, using tube material with better creep strength and by providing coating along the wall of the tube. The optimization of flue gas velocity is done by computational fluid dynamics software (ANSYS fluent), the boiler tube material is chosen based on the cost, creep strength and corrosion resistance, the coating for boiler tube is chosen based on operating conditions and coating feasibility. Apart from the above, providing protection shield over tubes and griddling bands. The above remedies if implemented in the power plants can reduce the tube failure to a major extent. This paper deals with the Economizer tube and Super heater tube failure analysis in the Thermal Power Station, remedial measures to prevent tube failures and the benefits after implementing such remedial action.