Power Plants Technologies
Power Plants Technologies
Open Cycle Power Plants
Both heavy duty and aero – derivative gas turbines ensure good efficiency, low pollutants emissions, high availability, moderate maintenance cost and a good weight/power ratio.
Gas turbines can be fed either with traditional fuels, such as natural gas or liquid fuel oil, or with renewable fuels like vegetal liquids, syn – gas, gas resulting from processes.
Reciprocating engines fuelled with traditional fuels, both liquid and gaseous, allow the realization of power plants that reach a high electric efficiency. It is also possible to feed these engines with renewable fuels such as palm oil.
Simple Cycle Power Plants
In a simple cycle power plant, a power generator, such as a gas turbine or a reciprocating engine, is employed for the production of electricity. The residual thermal energy that is contained in power generator exhaust is conveyed to a heat recovery boiler to be transferred to a selected thermal carrier vector or medium, like saturated or superheated steam, hot or superheated water, diathermic oil.
Combined Cycle Power Plants
In a combined cycle power plant the heat recovery boiler downstream the power generator (i.e. gas turbine or reciprocating engines) is employed as a steam generator to feed a steam turbine. There are different typologies of steam turbines:
- Backpressure steam turbine
The pressure of the steam at the turbine exhaust is higher than the atmospheric pressure, so the steam can directly feed the factory thermal users.
- Condensing steam turbine
The pressure of the steam at the turbine exhaust is lower than the atmospheric pressure and the steam is conveyed to a condenser (air-cooled or water- cooled type). The condensate is pumped to the deaerator first, then to the steam generator, so that the thermal cycle can be closed.
- Steam turbine with bleeds/extraction
Both backpressure and condensing steam turbines can be provided with bleeds or an extraction realized along the turbine stages, at suitable pressure in order to feed the factory specific thermal users.
Steam Power Plants (Hirn cycle) based on traditional fuels, renewable sources, process resulting gas
In these power plants a steam generator is fed by fuels such as natural gas, solid biomass (vegetal remains, agricultural by – products, waste), process resulting gas and produces steam to be conveyed to a condensing steam turbine (with or without bleeds) for electricity production.
The gasification (sub – stoichiometric combustion) of organic materials is a process that allows obtaining a gaseous fuel (syn – gas) to feed a reciprocating engine for power and possibly thermal production. We employ fuel made of pellets as starting material for the gasification process.