Tube Damage Mechanism and Analysis in Feed Water Heaters

Abstract

Steam power plants are responsible for the production of most electricity in the world. A small increase in the thermal efficiency of the plant means a large saving in fuel consumption. Therefore every effort is made to improve the efficiency of the cycle on which steam power plants operate. One of the major elements that increase the efficiency of the power plants is the feedwater heater. The study has been carried out to investigate the causes of tube failure of the high-pressure feedwater heaters in an electric power station. Specimens of the failed tubes were examined and photographs of the microstructure of the tube material were taken. Mechanical properties and the chemical composition of the tube material were also examined. A comparison between the failed tube and the new tube was made. The results of the laboratory test showed that the main reason for the tube failure is the OD (outside diameter) erosion. This effect is very clear, especially in desuperheating zone.