Auxiliary Boilers Can Reduce Cold-Start Times for CCGTs

Combined cycle gas turbines (CCGTs) play a critical role in providing power grids with additional electricity, supporting reliability and resilience during periods of high demand. Combined cycle power plants that harness energy from both combustion and steam turbines use less fuel overall, and can produce longer run times than traditional peaker plants that have long been used to produce electricity on demand.

Depending on the condition of a region`s electrical grid, CCGT plants may need to be operated for several hours each day, or just occasionally during a week, or perhaps even only a few times each year. However, regardless of their cycle frequency, these peaker plants must be able to quickly ramp up as they transition from "off" to "on" status.

One of the challenges for CCGT plants in that regard comes with starting steam turbines quickly after being offline. In a combined cycle power plant, a gas turbine initially generates electricity. The waste heat from the gas turbine is then captured via a heat recovery steam generator (HRSG), which produces pressurized steam that goes to the steam turbine, enabling the power plant to generate additional electric power.