Increasing Combined Cycle Gas Turbine Efficiency and Reliability

Emerson's Juan Panama


The electrical power generation mix continues to shift to increasing natural gas usage due to growing supplies from shale gas production. In a Power article, How to Increase Power Plant Asset Reliability Using Modern Digital Technology, Emerson’s Juan Panama describes how combined cycle gas turbine (CCGT) plants are using digital technologies to increase levels of reliability and efficiency.

He opens describing a typical CCGT unit that:

…use two gas turbines that feed their hot exhaust into a heat recovery steam generator (HRSG), powering a traditional steam turbine. As a result, all the equipment necessary to handle steam is required, such as boiler drums, condensers, pumps, and cooling towers.

Power: How to Increase Power Plant Asset Reliability Using Modern Digital TechnologyDigital technologies can help improve performance in three areas:

…reliability, availability, and heat rate… Some areas to focus on include pumps, cooling towers, boiler drums, steam leaks, and tube fouling.

Pumps, especially critical ones:

…will likely have continuous vibration monitoring to detect and predict bearing and seal failure, and other problems.

Analytics software:

…gathers data from these transmitters and provides analytics to detect problems at their earliest stages, such as increasing vibration noise from a motor bearing.

Similarly, fans on cooling towers can be instrumented with wireless vibration monitoring instruments to spot problems early and avoid unplanned shutdowns.

Boiler drums must maintain critical water levels.

Guided wave radar transmitters are available, and some include a digital technology specifically designed for drum level called dynamic vapor compensation. This technology reduces the level measurement error to less than 2%, even in dynamic conditions, while eliminating the maintenance problems related to traditional level measurement solutions.

Steam created drives the HRSG. Steam lost through leaky valves or steam traps wastes energy. Wireless acoustic monitoring devices can continuously monitor and identify leaks before excessive energy is lost.

Read the article for more on ways to identify tube HRSG tube fouling using wireless differential pressure transmitters and how analytics software uses the data collected to provide process experts the insights to maximize efficiency and reliability.

You can connect and interact with other wireless instrumentation and power industry experts in the Wireless and Power groups in the Emerson Exchange 365 community.

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