gas turbine - a motor, wherein during continuous operation of the main body of the device (rotor) turns the internal energy of the gas (in other cases, steam or water) into mechanical work plan.This jet of the working substance affects fixed around the circumference of the rotor blades, causing them to move.As the gas flow is divided into axial turbine (gas moves parallel to the axis of the turbine) or radial (perpendicular motion relative to the same axis).There are both single and multiple mechanisms.
gas turbine blade can act on two ways.Firstly, it is an active process in which the gas is fed into the working area at high speeds.This gas flow tends to move in a straight line and standing in his path curved blade of detail rejects it, turning itself.Second, a process of reactive type, when the gas flow rate is low, however, the high pressures used.A jet type in almost pure form does not occur, ie. A. In their turbines present centrifugal force that acts on the blades, together with the reaction force.
Where the gas turbine is used today?The principle of operation of the device can be used for drive of electric generators, compressors and others. Widespread turbines of this type have received the transport (marine gas turbines).Compared with steam analogues they have a relatively small weight and size, they do not need improvement boiler of the condensing unit.
gas turbine rather quickly ready for use after the launch, develops full power for about 10 minutes, easy to operate, requires a small amount of water for cooling.Unlike internal combustion engines, it has no inertial effects on the crank mechanism.Gas turbine and a half times shorter than diesel engines, and more than half the weight.The device has the ability to run on poor quality fuel.The above qualities suggest the engines of this kind of particular interest to the hovercraft and hydrofoil.
gas turbine engine as the main component has a number of significant drawbacks.Among them, high note noise of less than diesel engines, efficiency, short term operation at high temperatures (if used gaseous medium has a temperature of about 1100 ° C, the time of use of the turbine may be an average of 750 hours).
gas turbine efficiency depends on which system is used.For example, devices used in energy with the initial gas temperature above 1300 degrees Celsius, with the degree of air compression in the compressor 23 no more and no less than 17 are autonomous operations with a factor of about 38.5%.Such turbines are not very widespread and used mainly for covering load peaks in the electrical system.Today, about 15 gas turbines with a capacity of up to 30 MW of thermal power stations operate in a number of Russia.In multistage units it achieved a much higher rate of efficiency (about 0.93) due to the high performance components.