Maintain Gas Turbine Combustion Liner Performance With Thermal Spray Coatings
What does your typical industrial gas turbine do? This type of gas turbine occasionally provide electric power as base-load units but frequently provide electric power as peaking units. Fuel-burning takes place in a combustion basket or combustion liner. What that means for the components involved is severe service environment exposure. It is constantly present. To be of help, we may use thermal spray coatings for gas turbines.
What kind of severe exposure are we talking about here? Most times, the following must be tolerated:
- Induced by either air or fuel used in combustion… erosion.
- From elements in the fuel… corrosion.
- Temperatures that are extremely high.
- Thermal cycling repeatedly.
Applying Gas Turbine Coatings
To maintain component performance, thermal spray coating technology is used for most modern gas turbines. Ordinarily, the turbine manufacturer specifies the coatings for combustion liners. Typically consisting of a metallic layer, the gas paths are coated with a thermal barrier coating referred to as the “bond coat”. MCrAIY is the material used. It is an alloy of metals such as cobalt or nickel (or a combination), and aluminum, chromium, and yttrium. At high temperatures, this layer is very stable. In the combustion process, the component (its base alloy) is protected from hot gases produced because the layer is high temperature stable.
Additional Layers of a Gas Turbine
Once the application of the bond is finished, directly on top, a layer of ceramic is applied. Various forms of zirconium oxide are used to make up the ceramic topcoat usually employed. Applied using the plasma spray process, this two-layer system protects the metal of the combustion liner. Thermal cycle fatigue, erosion, and hot gas corrosion are guarded against. To protect wear areas of the liners, wear resistant coatings are frequently used in addition to the thermal barrier. One of a series of high temperature wear resistant designed alloys, or chrome carbide nickel chrome, are used for these coatings.
Power and Energy Industry Coating and Spraying Services
With the aim of furthering functionality, and to prevent power outage incidences, the development of specific coating solutions is provided. Reduce unnecessary equipment replacement costs, and more, by assuring that your power generators, gas turbines, and other equipment operates optimally for longer periods of time. For the energy and power industry, the following are coatings services frequently used…
For gas turbines:
- HVOF masking
- Plasma spray
In the application of TBCs (thermal barrier coatings) an important role is portrayed by plasma spray coatings and HVOF coatings. Frequently applied to hot zones, these TBC’s are used in the components of industrial gas turbines. Also applied to target areas are wear resistant and corrosion resistant coatings.
Power generation applications:
- Abradable coatings
- Dielectric coatings
- Various coatings within the range between the two
For equipment used in power generation, so that it can operate at its best efficiency and be well protected, the above-stated coatings are used. A variety of applications make good use of these coatings including the following:
- Industrial gas turbines
- Solid oxide fuel cells
- Solar energy generation… and more
A&A Coatings – Relied On By Power, Gas, and Energy Industries
At A&A Coatings, we have coated thousands of buckets and combustion liners – both repair components and OEM components. We have an extensive history of delivering superior field performance through the development of proven industrial solutions. Our high level of technical excellence supports our efforts.
Major industrial gas turbine manufacturers are already using our services. Contact us today if you’d like to know more.
