gas turbine's operate at very high temperatures. so a thermal barrier coating is necessary to protect the gas turbine components. TBC's have low thermal conductivity. they also protect against oxidation and hot corrosion.
Thermal coatings are highly advanced material systems applied to metallic surfaces, such as gas turbine or aero-engine parts, operating at elevated temperatures.
The product of zirconium and nitrogen is zirconium nitride. Zirconium nitride is a hard ceramic material with high melting point and good chemical stability, often used in cutting tools, coatings, and as a thermal barrier coating in gas turbine engines.
Materials used for thermal barrier coatings typically include ceramics such as zirconia, yttria-stabilized zirconia, and other rare earth oxides. These coatings are applied onto metallic components to provide thermal insulation and protection from high temperatures in various industrial applications such as gas turbines and aerospace components.
The gas (working fluid) having flown through the turbine does some work on the turbine, converting its thermal energy into mechanical work produced by the turbine and coming out as an expanding gas with lower temperature and pressure.
Inefficiencies in the compressor of a gas turbine cycle increase the back-work ratio and decrease the thermal efficiency of the gas turbine cycle, since they increase the compressor work.
by increasing the turbine inlet gas temperature
A modern combined cycle gas turbine/ steam turbine power plant can reach almost 60% efficiency.
1.Turbine output is increased for same compressor work. 2.As more heat is supplied,thermal efficiency decreases.
an increase in relative humidity will increase the Gas turbine output. and thermal efficiency. when the ambient tempeature is high at that time also if RH is high it will have a slight positive impact on GT output & Efficiency.
gas turbine generator
The prime mover in a thermal system is the component that generates mechanical energy from heat. This can be a steam turbine, gas turbine, or combustion engine, depending on the specific system. The prime mover converts the thermal energy into rotational motion to produce electricity or drive machinery.
In Cogeneration Plant : The generated steam in boiler is used for both power generation & process heating, thereby reducing the condenstion losses compared to thermal power plant. In combined cycle first is gas turbine , rather than wasting the flue gas from gas turbine, we are sending it into boiler and again generating steam for running steam turbine. Both the ways we are increasing the thermal efficiency of the plant