Fatigue Life Evaluation Of Flue Gas Turbine Blades

Catalytic cracking unit (FCCU) is one of main equipment for producing gasoline from heavy oil. It yield large high temperature (above 600°C) regeneration gas in the process of production. Generally, it will Waste the gas energy when making the gas go into the atmosphere after column washer. Flue gas turbine is primary equipment for energy recovery as heavy oil catalytic cracking unit (FCCU). It will generate electricity by exchanging the heat to mechanical energy. Currently, it is the most effective to recover energy in our country. It will bring huge economic loss of the whole system, if the flue gas turbine breakdown. The blade is important part for flue gas turbine, it works in high temperature and high speed, at the same time, it is also washing out by the catalyzer granule. So the flue gas turbine breakdown by the harsh environment in generally. The breakage of blade is for fatigue fracture, this is because the fatigue life of local is reduced by catalyst washed, then damage occurred affect by alternating load and creep. It is important for the whole equipment to exactly predict the fatigue life of blade, and have large economic and social benefits.This paper studied about the first and the second stage rotating blades of flue gas turbine. Making use of local stress and strain to calculated the fatigue life of blade by the effective of the work condition and catalyst washed. Details are as follows:The first, maked use of finite element analysis about three-dimensional elasticity-plasticity to the two level blades by ANSYS WorkBanch(AWE) , and used the result to calculate the models of blades, then analyzes the dangerous by resonance failure;The second, simulates the dents size of blades'key points, it was generated by the catalyzer granules impact from each angle;The last, used the result of finite element analysis about three-dimensional elasticity-plasticity to calculated the fatigue life of blades, getting distributed of the fatigue life. And considered the influence of the catalyzer granules impacting generated stress concentration factor, given the fatigue and creep total damage life of each danger points. After that, found out the least value as the flue gas turbine'life prediction. It was provides reference for the safe operation of the equipment.