What can be done to remove sulfidation deposits on turbine blades?
HP and IP blades require a nitric acid bath to remove sulfidation deposits, followed in special cases by a ferric chloride etch and abrasive blast to recondition the etched area.
What is the condition for increasing the chances of corrosion blades of turbine?
Explanation: The condition for increasing the chances of corrosion of blades of turbine is an increase in the pressure difference between which the Rankine cycle operates.
What failure is most likely to occur in a gas turbine blade operating at a temperature of 950 C?
High temperature hot corrosion is also known as Type I corrosion, which occurs in the approximate temperature range of 825°C to 950°C (Meher-Homji).
What are the causes of serious damage of turbine blade?
Generally, damage in wind blades can arise due to manufacturing defects, precipitation and debris, water ingress, variable loading due to wind, operational errors, lightning strikes, and fire. Early detection and mitigation techniques are required to avoid or reduce damage in costly wind turbine blades.
What is sulfidation corrosion?
Sulfidation Corrosion is a main source for causing leaks in piping and pressure vessels in the crude oil industry. Sulfidation Corrosion can lead to unplanned outages, large property losses and even injuries due to the naturally occurring sulfur compounds found in crude oil.
How do you prevent hot corrosion?
Diffusion coatings are achieved by enriching the surface of an alloy with either aluminum, chromium or silicon. Overlay coatings are corrosion-resistant alloys that are designed for high temperature protection. Thermal barrier coatings are used to insulate the substrate from the heat of the gas flow.
How does the superheating temperature of a Rankine cycle affect the efficiency?
Superheating the steam will increase the net work output and the efficiency of the cycle. It also decreases the moisture contents of the steam at the turbine exit.
What is the actual turbine inlet temperature in Rankine cycle?
What is the actual turbine inlet temperature in Rankine cycle? Explanation: The TIT(Turbine Inlet Temperature) is of the range 500-570C.
What is turbine blade failure?
Failures of gas-turbine blades can be due to creep damage, high-temperature corrosion, high-temperature oxidation, fatigue, erosion, and foreign object damage [1–15]. Obviously, in most cases the failure is due to the interrelation of more than one failure mechanism [2].
Which type of corrosion that is mainly responsible for failure of jet engine blades?
Several pits were found on the edges of the blades and chloride was detected in these pits. They were responsible for the crevice type corrosion. The failure mode was intergranular type.
Which type of corrosion is mainly responsible for failure of jet engine blades?
What causes sulfidation?
Generally sulfidation reactions occur on metals and alloys. Sulfur from airborne salts in some environments, and fuels in most cases, chemically react at high temperatures, with the oxides on the turbine blades, causing deterioration of the base alloy metal of the blades.
How does sulfidation occur in a turbine engine?
Every turbine engine uses fuel contaminated with sulfur, that when burned at high temperatures, emits varying amounts of sodium sulfate gas. Sulfidation is accelerated by the presense of catalysts.
What should the temperature be for sulfidation corrosion?
Sulfidation corrosion typically is of concern in sour oil services starting at temperatures in the 500F (260C) range. Up to that point, carbon steels are often acceptable, except in the most highly sour environments. In this case, “sour” means hydrogen sulfide (or other active sulfur compounds) containing oils.
What kind of corrosion occurs in a turbine?
But there is one form of corrosion that exists in the blistering environment of a turbine engine hot section, and it is called sulfidation (or sulphidation in some texts). The galvanic corrosion that eats away aircraft structures exists at normal temperatures and is an electro-chemical process.
Which is the most common high temperature corrosion?
High temperature sulfidation is probably the most common high temperature corrosion nemesis in the refining industry, since there are very few “sweet” refineries still in operation. Sulfidation corrosion typically is of concern in sour oil services starting at temperatures in the 500F…