Flexible aeroderivative power generation solutions
February 2017, Electrical Power & Protection
The importance of renewable power generation technologies such as wind, solar and tidal cannot be questioned. But what happens when there is no wind or sun and there are low tides? According to Siemens’ VP for power and gas sales in sub-Saharan Africa Andreas Pistauer, aeroderivative gas turbine technology is a flexible, economical and efficient alternative around-the-clock generation option, be it for peaking, or base load operation.
Efficient technology from the aeronautical industry
Siemens aero gas turbines are derived from turbojet/turbofan technologies, designed for civil and military aircraft, and are relatively new to the African power generation sector, which is accustomed to industrial gas turbines. Overall, Siemens aero gas turbines have a simple cycle efficiency that is typically 1-3% better than traditional industrial gas turbines.
The technology is a multi-spool design, where each spool rotates at its own optimal rpm for maximum efficiency across its operating range. Siemens aero gas turbines boast exceptionally high cycle capability, and can be started up in less than 10 minutes with no lockout timers after a shutdown (be it a normal or emergency shutdown). Electrical start-up is 500 kW, the equivalent of a small site backup generator.
These features bring the power closer to the operator, who is then able to respond instantaneously and follow load requirements with no impact to the equipment’s maintenance cycle, and no increase to its maintenance costs.
How is a jet engine converted into a gas turbine?
The Siemens fleet of Rolls-Royce aeroderivative products can be used as an example. The Aero Trent 800, which has more than 24-million flying hours in civil aviation applications, can be converted into the power plant specific Industrial Trent gas turbine, by simply replacing the fan with a two stage low-pressure compressor with matched flow capacity.
The Industrial Trent features three shafts (HP, IP, LP) that rotate independently and is environmentally friendly, as it is available in dry low emissions and wet low emissions cycle operation. Flexible maintenance solutions are available to ensure maximum return on investment.
Another important aspect of aero gas turbine technology is reliability and endurance under stress. The Industrial Trent requires no engine overhaul, as hollow shafts eliminate rotor bow and high nickel casings eliminate stress.
Titanium usage also reduces weight, thereby allowing for a higher power density. Operational expenditure is further reduced thanks to anti-friction bearings that require less lubrication. The ball bearing design is also lightweight with low oil flow and consumption.
Siemens aero gas turbines are therefore a low risk economic solution ideally suited to peak, mid-merit and base load applications, which can be used in open cycle, cogeneration and combined cycle power plants, with the key emphasis on having a power plant which offers greater operational flexibility.
For more information contact Jennifer Naidoo, Siemens Southern Africa, +27 (0)11 652 2795, email@example.com, www.siemens.co.za