Abstract

The power generation industry is facing unprecedented challenges.  High fuel costs and increased penetration of renewable power have resulted in greater demand for high efficiency and operational flexibility.  Imperatives to reduce carbon footprint place an even higher premium on efficiency.  Power producers are seeking highly efficient, reliable, and operationally flexible solutions that provide long-term profitability in a volatile environment.  New generation must also be cost-effective to ensure affordability for both domestic and industrial consumers. 

Gas turbine combined cycle power plants meet these requirements by providing reliable, dispatchable generation with a low cost of electricity, reduced environmental impact, and broad operational flexibility.  Start times for large, industrial gas turbine combined cycles are less than 30 minutes from turning gear to full load, with ramp rates from 60 to 88 MW/minute.   

GE introduced the 7/9HA industrial gas turbine product portfolio in 2014 in response to these demands.  These air-cooled, H-class gas turbines (7/9HA) are engineered to achieve greater than 63% net combined cycle efficiency while delivering operational flexibility through deep, emission-compliant turndown and high ramp rates.  The largest of these gas turbines, the 9HA.02, is designed to exceed 64% combined cycle efficiency (net, ISO) in a 1x1, single-shaft (SS) configuration.

Full-Speed, Full-Load testing of the 9HA.02 was completed in fourth quarter of 2019.  This full-production, test unit achieved full load on both gaseous and liquid fuel.  Detailed operational, life-cycle and performance data were collected and have been analyzed by the engineering team.  Both output and efficiency exceed initial engineering predictions.  Operability was very good across the load range with rotor dynamics, aeromechanic blade response and combustion dynamics below engineering specifications.  Multiple fuel transfers were performed from gas-to-liquid and liquid-to-gas.  Grid code testing verified unit capability to meet or exceed the most stringent regulatory requirements.   

As of December 2019, a total of 42 7/9HA power plants have achieved COD (Commercial Operation Date) while accumulating over 500,000 hours of operation.  These plants operate across a variety of demand profiles including base load and load following (intermediate) service.  These plants have proven themselves robust to multiple grid disturbances with capability to operate through both off-frequency and low-voltage conditions.  Fleet leaders for both the 7HA and 9HA have exceeded 20,000 hours of operation, with multiple units over 8,000 hours.  Fleet reliability for the 7/9HA gas turbines as monitored by GE’s reliability team is in excess of 99.0%.

This paper will address four topics relating to the HA platform:  1) gas turbine product technology, 2) gas turbine validation, 3) integrated power plant commissioning and operating experience, and 4) lessons learned and fleet reliability.