Gas turbines work on a thermodynamic cycle termed Brayton cycle after George Brayton. This fundamental cycle now powers jet engines used in air crafts, helicopters and submarines and turbines used in power generation.
While Brayton implemented the theory in practical, workable designs, the idea was not new since John Barber, an Englishman, patented a design as far back as 1791.
Open Gas Turbine Cycle Engine: In which the exhaust gases are expelled into the atmosphere.
Closed Loop Brayton Cycle: This is also known as the ideal Brayton cycle that is achieved with a closed loop configuration in which, the exhaust gases are partly recycled through a heat-exchanger and is fed back to the compressor. This type of set up is common in power generation stations and pumping stations.
Reversed Brayton Cycle: This engine is driven in reverse through a network to expel the cool air. This principle works in air conditioners and air refrigeration cycle that works to remove heat and cool the atmosphere.
The main parts of gas turbines operating on the Brayton cycle comprise of:
The nozzle through which exhaust gases flow out and provide thrust to the aircraft.
The Brayton cycle works in four stages in a typical jet engine operating on this principle:
The combustion process is continuous in the brayton cycle, unlike the piston based Otto-cycle engines. In an open cycle Brayton process, air is taken in and expelled from the nozzle and expanded to ambient conditions. In a closed cycle the fluid or gas is recirculated in a loop through a heat exchanger and sent back to the compressor.
The challenges of the Brayton Cycle Engines:-
These Engines are high-grade equipments which are inspected regularly for maintenance requirement that is performed only by an authorized personnel. Some of the usual wear and tear are -