Gas Turbines - Combined Cycle

For more than half a century, GE has been an industry leader in combined cycle technology and today leads the industry in installations around the world. 

GE has developed advanced combined cycle technology that uses an integrated approach to improve the overall plant through systematic simplification with a focus on increasing efficiency and operational flexibility. GE’s latest combined cycle power plant is comprised of advanced air-cooled gas turbine technology, a water-cooled generator, an advanced steam turbine with double-flow side exhaust, and an innovative plant control system for accurate maintenance schedules and improved life-cycle costs.

How it works

Combined cycle power plants feature a gas turbine that generates electricity using natural gas as a fuel in addition to a steam turbine that generates electricity using the waste heat from the gas turbine as its fuel.

 

A gas turbine compresses air and mixes it with fuel. The fuel is burned and the hot air-fuel mixture is expanded through turbine blades, making them spin. The spinning turbine drives a generator which converts the spinning energy into electricity.

  • Fuel is burned in the gas turbine
  • The resulting energy in the gas turbine turns the generator drive shaft
  • Exhaust heat from the gas turbine is sent to a heat recovery steam generator (HRSG)
  • The HRSG turns the gas turbine exhaust heat into steam and feeds it to the steam turbine
  • The steam turbine delivers additional energy to the generator drive shaft
  • The generator converts the energy into electricity

 

 

Features & Benefits

Today’s combined cycle plants have moved from base load to cyclic duty operation to accommodate the increased demand of renewables on the grid.

GE’s combined cycle power plant solution provides the most operational flexibility, proven performance and highest reliability in order to produce more power, more efficiently, resulting in increased revenues for power generators. 

GE’s FlexEfficiency* 50 Combined Cycle Power Plant:

  1. Industry-Leading Start Capability.GE's plant offers start capability of 28 minutes for hot starts and start reliability of greater than 98%.

  2. Fast Ramp Rates. Plant improvements have resulted in a 51 MW per minute ramping capability and improved load adjustment capability.

  3. Improved Turndown. GE’s plant offers turndown of less than 40% of base load within emissions compliance.

  4. Fuel Flexibility. GE’s plants have both a distillate fuel back-up option and a modified wobbe index variation of +/- 10%.

* Trademark of the General Electric Company

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