For the operation of industrial and economic facilities located at a considerable distance from centralized power lines, small-scale power generating installations are used. They can function on various types of fuel. The most widely used gas turbine power plants due to their high efficiency, the ability to generate thermal energy and a number of other features.
Operating principle
The basis of a gas turbine power plant (GTES) is a gas turbine engine - a power plant operating on the energy of combustion of gaseous fuels, mechanically coupled to electric generators and combined with them into a single system. The gas turbine unit is the most powerful internal combustion engine. Its specific power can be 6 kW / kg.
Unlike other types of power plants, in gas turbine engines, all processes occur in the flow of a constantly moving gas. Compressed air compressors with the fuel enters the combustion chamber. The mixture ignites with the release of a large number of high-pressure combustion products that press on the blades, rotate them, and with them the electric generators.
The capacity of a gas turbine power plant varies from 20 kilowatts to several hundred megawatts. As a fuel, any combustible material can be used that can be dispersed (finely ground) and presented in a gaseous form.
GTES advantages
An important advantage of gas turbine power plants is the possibility of the simultaneous use of two types of energy - electrical and thermal. Moreover, the amount of heat given to the consumer is two to three times more than the amount of electricity generated. Cogeneration (the process of generating two types of energy) becomes possible when a special recovery boiler is installed on the turbine exhaust.
Using gas turbine power plants, it is possible to create autonomous
energy complexes that can solve several problems simultaneously:
- Provide electricity to private and industrial facilities.
- Dispose of by-product gas during oil production.
- Heat technical rooms and residential buildings with secondary heat.
All this allows to significantly reduce the cost of providing the enterprise, to create optimal conditions for staff work and to concentrate material resources and capital on expanding production and solving other, more important tasks.
Features of gas turbine power plants
One of the main features of GTES is the ability to operate on almost any type of fuel. As previously noted, gas turbine power plants can use fuel that can be dispersed to operate. As such, gasoline, fuel oil, oil, natural gas, alcohol and even crushed coal can act.
In the design of the gas turbine power plant there are practically no moving elements. The only moving part that combines the generator rotor, turbine wheels and compress can be suspended using a gas-dynamic bearing. As a result of this, the wear of the working units will be minimized, which will significantly affect the durability of the installation.
At the same time, the period of interservice maintenance increases to 60 thousand hours of continuous operation or up to 7 years of operation. Gas turbine power plants cannot be used as backup energy sources, because at the time of start-up, parts wear out especially intensely. The number of installations starts is limited to 300 per year.
Mobile GTES
A special place in the industrial sector is occupied by mobile gas turbine units. Unlike conventional gas turbine power plants, they have smaller dimensions and weight, are equipped on a mobile platform and equipped with electronic control systems. As a rule, such complexes are used to restore the supply of electricity to the facility.
A mobile gas turbine power plant is deployed in paved areas providing a stable position. A fuel line is supplied to it, and a
transformer substation is installed in the immediate vicinity
. The deployment time depends on the type of installation, but usually does not exceed 8-12 hours.
The power of mobile units varies from 5 to 25 MW. At the same time, the efficiency of mobile gas turbine power plants begins to grow from 35%. Like stationary power plants, mobile complexes also emit thermal energy. But along with this they create less costs associated with the operation and commissioning.
Combined cycle power plants
A combined cycle plant can be called a modification of a gas turbine power plant. Like gas turbine plants in power plants, such generators use the energy of combustion of dispersed fuel. But passing through the turbine, gaseous products give only part of their energy and are released into the atmosphere in a heated state. Combined cycle plants use this heat.
The design of combined-cycle electric generators has a steam-powered installation, which is located in the end of the turbine. It contains water that boils from heated combustion products. A huge amount of steam is formed, which rotates the turbine and drives an additional generator.
Gas turbine and combined cycle power plants can be used in all industries, but the second type of generators is preferable, because their efficiency is more than 60%.
Scopes of GTES
The use of gas turbine installations is advisable for consumers remote from centralized power supply lines, as well as for seasonally functioning facilities. In this case, the cost of providing the enterprise with electricity will be lower than the cost of connecting to power lines.
It is advisable to use large-sized gas turbine power plants instead of thermal power plants if there is a cheap fuel source. This situation is typical of the oil and gas regions of the North. At the same time, it is possible to save on space heating.
Recently, a mobile gas turbine power plant has become widely used in urban areas due to the low level of noise, vibration and toxicity of exhaust gases. It is advisable to use it in cases where the connection to the city’s power grid is difficult or the cost of the latter is too high.