Among the many trends affecting the larger electric utility industry is the change in generating plant fuel sources. For years now, coal has been losing ground to natural gas, and the trend seems irreversible. Part of the change is reflected in new plant construction as combined-cycle gas turbine (CCGT) plants are replacing many old coal plants. New CCGT plants are more environmentally friendly and far easier to build close to customers, without all the rail and barge unloading, and those ugly coal piles.
CCGT plants can be very complex, with a lot of equipment on a small footprint, and keeping them running efficiently takes some doing. In an article in the February, 2018 issue of Power, Juan Panama published an article, How to Increase Power Plant Asset Reliability Using Modern Digital Technology. He points out how much equipment is necessary to get the high efficiency these plants count on.
Most CCGT units 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. This leaves many places where reliability and efficiency can be gained or lost, so improvements can have a large impact, with modern digital technology often employed to realize benefits.
These plants have some of the same equipment as their coal-burning counterparts and then some. Without careful control and optimization, the efficiency gains made in the gas turbines can be lost in the steam sections. Operators have many areas to watch over.
A plant looking to improve performance and profitability should examine three key areas: reliability, availability and heat rate. With a few basic digital technologies and applications, a CCGT can improve in all three of these areas, boosting output while reducing costs to produce greater profitability. Some areas to focus on include pumps, cooling towers, boiler drums, steam leaks and tube fouling.
There are technologies designed to make this kind of monitoring possible and practical. A new generation of WirelessHART instruments, combined with supporting software platforms like Plantweb Insight, provide the means to realize maximum efficiency and reliability from these new facilities without huge implementation costs.
Using self-powered transmitters communicating via WirelessHART is a simple way to implement a solution. Applications are available to turn the data from these acoustic transmitters into actionable information. These apps are some of the newest innovations in digital technology, using pre-built analytics with embedded domain expertise to diagnose the health of plant assets. The resulting information and insights can be accessed and visualized on a web-user interface. Dashboards and charts make navigation and interpretation of information simple, so minimal training is required. The apps include features to ensure security, including role-based access.
Juan discusses the group of applications critical to CCGT operation in greater detail, including how monitoring can improve performance in multiple ways, so the full article is well worth a careful read. Tools like Plantweb Insight combined with the new generation of wireless sensors can improve operations on all these fronts.
Analytics can find the cause-and-effect relationships driving plant performance by watching key performance indicators and answering critical questions capable of moving the needle in the right direction. This connectivity, data collection and analysis provide fulfillment of the digital plant’s promise, allowing managers and operators to view actionable information in real-time from any part of the operation.
You can find more information like this, and meet with other people looking at the same kinds of situations in the Emerson Exchange365 community. It’s a place where you can communicate and exchange information with experts and peers in all sorts of industries around the world. Look for the WirelessHART and IIoT Groups and other specialty areas for suggestions and answers.