The efficiency depends primarily on size (different manufacturtes have use similar designs). Bigger Gas Turbines tend to more effiecient. Additional factors such as waste heat recovery and heat exchangers can improve the system efficiency (but not the effiecency of the actual Gas Tubine).
Smaller gas turbines such as the Rolls Royce Avons have around 25% Thermal Efficiency while larger units such as the Rolls Royce Trent-50 have efficiencies of around 42%. A full list of Tubine Efficiencies for different manufacturers can be found at http://www.vibronurse.com/turbmath.HTML
Note that the above comment does not make the Avon a bad unit its simply the case that it is designed primarily for a high power to weight ratio. Some people will also quote very high figures for G.E Frame machines (+50%) but these numbers usually include co-gen (a steam turbine used to recover waste heat) and are therefor not just Gas Turbine Efficiency.
The full calculation for calculating Gas Turbine effieciency is avalaible at VibroNurse at the following page (http://www.vibronurse.com/turbmath.HTML) and program which does the calculation is available at http://www.vibronurse.com/gaseff.HTML. We use this program at our oil and gas platforms and it works well particlauarly as a condition monitoring tool.
A modern combined cycle gas turbine/ steam turbine power plant can reach almost 60% efficiency.
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
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.
1.Turbine output is increased for same compressor work. 2.As more heat is supplied,thermal efficiency decreases.
The efficiency of a Turbine, is roughly 40%.
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
Gas turbine manufacturers generally state the efficiency of their turbines using LHV. However, natural gas in the U.S. is bought and sold on an HHV basis, so be careful that you don't mix units. Otherwise, you will buy a gas turbine that is too small for your anticipated needs.
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.
www.muellerenvironmental.com/documents/GER3567H.pdf discusses many factors affecting gas turbine efficiency. It specifically addresses GE turbines, but the factors discussed are relevant to all gas turbine power generators.
A simple-cycle gas turbine used for power generation has a thermal efficiency of about 34 percent. Since 1 kwh is theoretically equivalent to 3,415 Btu, the simple-cycle gas turbine has a fuel connsumption of: 3,415 / 0.34 = about 10,000 Btu/kwh. Given the heating value (i.e, heat of combustion) of a fuel, we can easily calculate the simple-cycle gas turbine fuel usage. For example, natural gas has a net heating value of about 21,500 Btu/pound. Thus, the natural gas consumption in a simple-cycle gas turbine would be: 10,000 / 21,500 = 0.47 pounds/kwh = 0.21 kg/kwh. As another example, a typical diesel oil has a net heating value of 130,000 Btu/gallon. Thus, the diesel oil consumption in a simple-cycle gas turbine would be: 10,000 / 130,000 = 0.077 gallon/kwh. (The gallon used just above is the U.S. gallon rather than the Imperial gallon) A combined-cycle gas turbine will have a higher thermal efficiency and, hence, lower fuel consumptions.
The steam turbine will produce 400 J of output, and the steam engine 250 J. That's what the efficiency figure means.
A steam turbine extracts thermal energy for steam, hence it's use in a thermal power plant.
Thermal coatings are highly advanced material systems applied to metallic surfaces, such as gas turbine or aero-engine parts, operating at elevated temperatures.
gas turbine generator
A free turbine engine is a type of gas turbine engine, where the power turbine and the gas producer turbine are not connected by a solid shaft
The amount of energy transferred from the steam is a function of the temperature difference between the input and output of the turbine. Also, superheating the steam ensures that there are no water molecules that can damage the turbine blades.
Neither. Natural Gas is Chemical Energy. In a thermal power station, the gas will be burned, heating the water. This is now heat energy. The superheated water (steam) will be blasted through a turbine or similar device. This then becomes kinetic energy or mechanical energy. The turbine then turns a generator/alternator. This converts the kinetic energy to electrical energy.
by calculating the inlet steam enthalpy-outlet steam enthalpy we will know the total kcal consumed for output mw required kcal for 1 kwh=860 now campare this with your turbine kcal for 1kwh now you came to know how much is your turbine efficiency................................................................................
Thermal energy is just heat. To convert it to mechanical energy you need some sort of heat engine, like an internal combustion engine or a gas turbine.
steam turbine having more efficinency and using direct steam, wheras gas turbine using used gas .
Gas turbine works on bryton cycle where as steam turbine works Rankine cycle. Construction, operation of a gas turbine are entirely different to steam turbine. Gas turbine has a compressor to compress the combustion air, a combustion chamber to burn the fuel and a turbine section to extract the work for burning fuel. Steam turbine is just has a turbine section to extract the work from steam.
A gas turbine is one type of power plant. It produces power by burning gas to turn the turbine.