More power or longer intervals?

Power Crystal increases turbine heat resistance and power output

GE’s new Power Crystal technology is based on the advanced properties of single-crystal materials. With single-crystal materials, all grain boundaries are eliminated from the structure, and the controlled orientation results in a substantial increase in the melting point of the alloy. This creates a corresponding increase in the resistance of the final manufactured product to extreme heat, as well as greater creep and fatigue strength compared with equiaxed or Directionally Solidified (DS) structures.

Single-crystal technology has been proven by GE Aviation in a wide range of jet engine applications for more than 15 years – with its most famous and successful engines, such as the CFM and CF6, relying on the outstanding properties of single-crystal alloys.

In 2007, GE’s Oil & Gas business applied the technology to create the Power Crystal upgrade kit for our Frame 5 C and D gas turbines. The upgrade enables a higher firing temperature without additional cooling or significant impact on NOx emissions.

Power Crystal turbines can deliver 4-6% more power, and the firing temperature can be raised by at least 40°F. In climates where the ambient temperature changes dramatically between seasons or even from day to night, this allows operators to offset the performance dips caused by an increase in ambient temperature.

Thanks to the Extendor technology embedded in Power Crystal units with either standard or LHE combustors, the mean time between maintenance can be increased to 24,000 equivalent running hours – enabling the traditional 12,000-hour combustion inspections to be skipped. The baseline maintenance plan for a Power Crystal unit calls for a Liner and Transition Piece Inspection at 24,000 hours and a Major Inspection at 48,000 hours. If, however, the firing temperature is not increased, the major inspection can be postponed to 72,000 hours. In a typical LNG application, this can translate into 10 days of extra production over a full maintenance cycle – equivalent to about $20 million in additional revenue.

The Power Crystal kit includes:

• 1st stage buckets of single crystal material
• 1st stage nozzles with new cooling pattern
• New material for 1st stage shroud
• Modified 1st stage nozzle support
• ExtendorTM embedded in the combustion kit