Plasma ignition system

Microwave Plasma Solid Fuel Ignition System MiPS-SFI has been successfully installed in the boiler-house of the thermal power station Soma Elektrik Üretim AŞ. (SEAS). 

In 2012, the power plant first started heating its boilers without oil by having been equipped with a plasma heating system and receiving several upgrades. Each of which was aimed at improving the various process operations of the units in order to increase fuel efficiency and reduce the cost of electricity production. 

Currently, the thermal power plant produces electricity using cheap low-grade high-ash coal from the Afşin-Elbistan field without spending any additional highly reactive fuels. Natural gas, oil or diesel, is not used to heat its boilers and stabilize the burning of coal torches. The coal used for electricity generation is more than three times less caloric than the project had envisaged. In fact, their caloric content does not exceed 1000 kcal/kg. 

An important aspect of the modernization of existing Thermal Power Plants and the installation of the MiPS-SFI System is the technical accessibility and minimization of the required reconstruction. Retrofitting of boilers with microwave burners hardly affects existing equipment. 

The MiPS-SFI System, operated by Soma Elektrik Retim AŞ. (SEAS) is composed of four burner units with PTC-5 microwave plasmotrons as well as a coal fuel preparation and supply system. 

A big technical advantage of our design is that the coal dust is fed directly into the plasmotron, which has made it possible to achieve high efficiency of fuel flow interaction with plasma. All the while the energy consumption for creating the plasma and maintaining the process in the boiler is not more than 0.15% of the heat output of the burner.

            Microwave Plasma Solid Fuel Ignition System MiPS-SFI description: 

1. Coal dust feeders supply fuel from an intermediate bunker to the inlet of the plasma coal burner of the boiler. Coal dust is supplied by transporting air.
2. PTC-5 microwave plasmotrons operate continuously. The coal dust passes directly through the plasma and is thermochemically treated. A combustible mixture is formed at the plasmotron outlet, the combustion of which is equivalent to the combustion of high-energy fuels (natural gas, fuel oil, diesel). A steady flame is formed into which the primary stream of coal fuel is fed through the second stage.
3. The hot air from the boiler through the air heaters is directed to the coal drying prior to grinding in the coal mills before being fed to the boilers for incineration.
4. There is a gradual increase in fuel delivery and boiler load until normal operation. At the same time, the plasma torch power is gradually being reduced to the level required to stabilize coal fuel combustion. Plasmotrons can be switched off completely and switched on again if necessary. It takes 3-5 minutes to start the plasmotron and to regulate its power level.
5. The whole process of oil-free boiler heating and coal fuel combustion stabilization is controlled by a digital control system with continuous analysis of boiler operation.

Applying the Microwave Plasma Solid Fuel Ignition System MiPS-SFI allowed to achieve:

• Reduction of boiler heating time from a cold state by 2-2.5 times;
• Conversion of the power station to cheap low-grade, high-ash coal instead of conventional coal. No additional high-energy natural fuels (oil, natural gas, diesel);
• Increase in the manoeuvrability of the equipment, which allows the boiler load to be reduced up to 30% of the rated power;
• Reduction of mechanical fuel nonburn, stabilization of equipment working regimes and, as a result, improvement of the power plant’s environmental performance.

Operation of the Microwave Plasma Solid Fuel Ignition System MiPS-SFI in the boilers of the power station has shown the possibility of ignition based on plasma technology for a wide range of classes of energy coal in boilers with direct coal dust injection through a microwave plasma burner. This leads to a significant reduction in the cost of electricity generation converting the power station to a much cheaper fuel and by avoiding the cost of purchasing and using oil and diesel fuel in the production cycle. 

Operation of our system has demonstrated that the process of oil-free coal combustion can significantly reduce the cost of electricity generation and increase the efficiency of carbon fuel use. At the same time, it will ensure excellent environmental performance through emission reductions and process optimization.