The Complete Guide to Gas Turbine

What is a Gas Turbine?

Gas turbines are engines in which the chemical energy of the fuel is converted into mechanical energy in terms of kinetic energy. The thermodynamic process employed in gas turbines is the Brayton cycle. There are two significant performance parameters: the pressure ratio and the firing temperature, which will be discussed further. Gas turbines present one of the cleanest means for electric power generation with fairly low carbon dioxide (CO2) and oxides of nitrogen (NOx) emissions. The available gas turbines cover a wide range of capacities. Gas turbines are well suited for Combined Heat and Power (CHP) and Combined Cooling, Heating, and Power applications because high-pressure steam can be produced from their high-temperature exhaust using Heat Recovery Steam Generators (HRSGs). Gas turbines have two main applications in modern industries, including "turbo generators" and "turbo compressors". Gas turbines offer flexibility in using a range of liquid and gaseous fuels.

What are Gas Turbine Parts?

Gas Turbines basically consist of three main sections:

1. The Compressor, which pulls air into the engine, pressurizes it, and feeds it to the combustion chamber.
2. The Combustion system, is made up of a ring of fuel injectors that perfuse a steady stream of fuel into combustion chambers in which the mixing process with the air happens.
3. The Turbine, is an intricate array of alternate stationary and rotating aerofoil-section blades.

As hot combustion gas expands through the turbine, it spins the rotating blades. The rotating blades perform a dual function: they drive the compressor to draw more pressurized air into the combustion section, and they turn a generator to produce electricity. The mentioned basic parts also consist of some components, including inlet nozzles, pipes that serve the transport of mass flow from the compressor to the turbine for cooling purposes, control systems, valves with the operation ramp defined by the control system, bearings, lubrication systems, and electric motors for power supply.

The Compressor pulls air into the engine, pressurizes it, and feeds it to the combustion chamber.

The Combustion system is made up of a ring of fuel injectors that perfuse a steady stream of fuel into combustion chambers in which the mixing process with the air happens.

The Turbine is an intricate array of alternate stationary and rotating aerofoil-section blades.

As hot combustion gas expands through the turbine, it spins the rotating blades. The rotating blades perform a dual function: they drive the compressor to draw more pressurized air into the combustion section, and they turn a generator to produce electricity. The mentioned basic parts also consist of some components, including inlet nozzles, pipes that serve the transport of mass flow from the compressor to the turbine for cooling purposes, control systems, valves with the operation ramp defined by the control system, bearings, lubrication systems, and electric motors for power supply.

What are Gas Turbine Types?

In a power generation gas turbine, air from the environment enters the inlet nozzle, and after passing through the inlet, air enters a multi-stage compressor, where its total pressure continuously grows to reach the design pressure ratio at the outlet of the compressor. The pressure increment is performed by supplying mechanical energy through the turbine. The working medium air leaves the compressor outlet at a relatively high total temperature and total pressure based on the compression pressure ratio. It then enters the combustion chamber, where fuel is supplemented. Within the combustion chamber, an intensive combustion process occurs, where the fuel's chemical energy is converted into thermal energy. The energy conversion process continues within the exit diffuser, where the kinetic energy of the exiting gas is partially converted into potential energy. Due to the power required to drive the compressor, energy conversion efficiency for a simple cycle gas turbine power plant is typically around 30 percent. Even the most efficient designs are limited to 40 percent. Achieving higher efficiency required a substantial increase in Turbine Inlet Temperature (TIT), requiring extensive cooling of the front turbine stages.

What is Gas Turbine Cycle?

In a power generation gas turbine, air from the environment enters the inlet nozzle, and after passing through the inlet, air enters a multi-stage compressor, where its total pressure continuously grows to reach the design pressure ratio at the outlet of the compressor. The pressure increment is performed by supplying mechanical energy through the turbine. The working medium air leaves the compressor outlet at a relatively high total temperature and total pressure based on the compression pressure ratio. It then enters the combustion chamber, where fuel is supplemented. Within the combustion chamber, an intensive combustion process occurs, where the fuel's chemical energy is converted into thermal energy. The energy conversion process continues within the exit diffuser, where the kinetic energy of the exiting gas is partially converted into potential energy. Due to the power required to drive the compressor, energy conversion efficiency for a simple cycle gas turbine power plant is typically around 30 percent. Even the most efficient designs are limited to 40 percent. Achieving higher efficiency required a substantial increase in Turbine Inlet Temperature (TIT), requiring extensive cooling of the front turbine stages.