Optimizing Combined Cycle Operations

by , , , | Sep 4, 2024 | Industrial Software, Power Generation | 0 comments

Emerson’s James Nyenhuis, Ranjit Rao, and Jonathan Gillam presented Consistent and Optimal Combined Cycle Operations at the 2024 Ovation Users Group Conference. Here is their presentation abstract.

The increase of renewable assets on the power grid are requiring combined cycle plants to cycle and move load more frequently. This abstract will discuss the process of analyzing the operation of a unit over time using the Ovation Process Analytics Studio. From that evaluation, the following areas of operation and control can be assessed with a look toward optimization.

  1. Advanced Bypass Control
  2. Advanced Drum Level Control
  3. Advanced Inlet Pressure Control
  4. Advanced Pump Protection
  5. Duct Burner Optimization
  6. Procedure Integration

Improvements with some or all of these areas of CC operation when combined with the consistency of startup and shutdown procedure integration can greatly enhance performance and reliability with an increase in unit flexibility.

James opened by sharing how the world we operate in is changing. As conventional assets transition towards supporting and absorbing the ebb and flow of renewable MWhs, there is an increased demand for current automation systems to manage the daily cycle dynamics better. Wholesale markets are increasingly giving price signals to incentivize increased unit rates of change. In competitive situations, improved operational dynamics can provide tangible revenue benefits.

A large percentage of North America’s combined cycle plants cycle frequently, taxing the generation assets. Predictive models can help estimate fuel usage for differing start types for these cycles to support efficient market engagement.

Using the model data, Ovation Analytics Studio can use real-time, historical, and other operating data to identify optimization opportunities given these intermittent operation modes. One example James shared was tracking cycling variability for hot CT/HRSG cycles, looking at the per-start variability of fuel usage.

In the Analytic Studio, with connectivity to the historian, a conditional extraction function pulls data from the flame on to release to dispatch for the gas turbine trains over a year to identify all the unit startups. The resulting query captures all the starts events including the durations.

After identifying these starts, we can examine individual points in the startup, such as fuel flow and drum pressure. Totalization calculations can be applied to provide integrated fuel use during the startup to determine its consistency per start type over time.

The consulting team’s general approach is to use the Ovation analytics tools to perform an operational analysis, apply advanced power applications to ensure the most robust and optimal control capabilities, and apply sequential automation to drive higher levels of automation and consistency.

Ranjit discussed advanced bypass control application as an example which provides better resilience and management of significant load rejections from the steam turbine. It supports an optimal response to significant load rejections in the process and increased reliability during bypass system blending and un-blending.

Steam turbine bypass control

The advanced bypass control application:

  • Better manages piping thermal conditions, reducing stress on critical bypass piping
  • Assesses bypass valve and attemperation sizing and actuation via historical data
  • Delivers a first principle-based energy balance driven attemperation control scheme
  • Model predictive bypass pre-positioning on plant upsets
  • Bypass system protection functions and leak mediation schemes
  • Bypass attemperator control based on optimal temperature & enthalpy control for protection of condenser and piping per HEI and EPRI recommendations

Other applications Ranjit highlighted included advanced drum level control, advanced inlet pressure control, advanced pump protection control, duct burner optimization, and procedural integration.

Here is a summary of Ovation Advanced Control applications for Combined Cycle and Coal-Fired power generation plants.

Ovation APC applications for Combined Cycle Power Generation Plants

Visit the Ovation Power Plant Optimization Software section on Emerson.com for more information on ways to drive overall performance improvements and more sustainable operations.

Popular Posts

Comments

Author

Featured Experts

Follow Us

We invite you to follow us on Facebook, LinkedIn, Twitter and YouTube to stay up to date on the latest news, events and innovations that will help you face and solve your toughest challenges.

Do you want to reuse or translate content?

Just post a link to the entry and send us a quick note so we can share your work. Thank you very much.

Our Global Community

Emerson Exchange 365

The opinions expressed here are the personal opinions of the authors. Content published here is not read or approved by Emerson before it is posted and does not necessarily represent the views and opinions of Emerson.

PHP Code Snippets Powered By : XYZScripts.com