Gas Turbine Plenum Pressure Control for Emission Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Gas turbine assemblies in power plants face challenges in reliably controlling pollutant emissions, particularly NOx and CO, at transient loads below the Minimum Environmental Load (MEL), where existing methods are not stable and efficient.

Innovation Solution

A method for operating a gas turbine assembly that controls the combustor based on plenum air pressure, regulating fuel supply and burner operation to maintain pollutant emissions within legal limits, by calculating CO emissions and switching off parameters using pressure measurements, temperature, and burner status.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the gas turbine assembly is operated at transient loads between minimum load and base load, then the power output adapts to network demand, but pollutant emissions are not controlled reliably and stably

Engineering Contradiction:
Improvepower output adaptationVSAvoidemission control stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The control system continuously measures plenum pressure and uses this feedback to dynamically adjust fuel supply and burner operation. This closed-loop control ensures that emissions remain stable and reliable across varying load conditions by constantly adapting to changes in plenum pressure that correlate with fuel mass flow rate

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention changes the control parameter from traditional flow-based measurements to plenum pressure measurement. This parameter change provides a more reliable and stable indication of fuel mass flow rate, enabling consistent emission control across the entire operating range from minimum to base load

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If burners are switched off to manage emissions at partial loads, then fuel consumption decreases, but emission control becomes unreliable

Engineering Contradiction:
Improvefuel consumptionVSAvoidemission control stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

Instead of static on/off burner control, the system dynamically adjusts the number of active burners and their individual fuel supply based on real-time plenum pressure measurements. This dynamic control maintains emission stability across varying loads by continuously optimizing burner operation rather than using fixed switching thresholds

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses plenum pressure as a continuous control parameter to determine burner operation, replacing discrete on/off control logic. This parameter-based approach ensures smooth transitions and reliable emission control by adjusting burner fuel supply proportionally to plenum pressure changes

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach ensures stable and reliable control of pollutant emissions at all load operations, improving reliability and stability by correlating plenum pressure with fuel mass flow, effectively keeping CO emissions under limits and ensuring compliance with environmental regulations.

Implementation Method 1

controlling the combustor assembly on the basis of at least one parameter indicative of the pressure of the air measured in the plenum

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 2

a plurality of rotating blades compressing the passing air. The compressed air leaving the compressor flows into a plenum

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

Inside the combustor, the compressed air is mixed with at least one fuel and combusted. The resulting hot gas leaves the combustor and expands in the turbine

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

In the turbine the hot gas expansion moves rotating blades connected to a rotor, performing work

Methodology Applied
Scientific EffectHot gas expansion:

Data Source

PatentEP3845813B1Method for operating a gas turbine assembly and gas turbine assembly
Publication Date: 2024.04.03 ANSALDO ENERGIA SWITZERLAND AG
  • EP3845813B1 patent drawingFigure 1
  • EP3845813B1 patent drawingFigure 2
  • EP3845813B1 patent drawingFigure 3

AI summary

A gas turbine assembly (1) extends along a longitudinal axis (A) and comprises a compressor (2), a combustor assembly (4) and at least one gas turbine (5); the compressor (2) comprising an inlet (9) supplied with air and an outlet (10) through which the air compressed by the compressor (2) flows; the outlet (10) of the compressor (2) coming out into a plenum (3), which is in fluidic communication with the combustor assembly (4); the combustor assembly (4) comprising at least one combustor (15) coupled to the gas turbine (5) and provided with a plurality of burners (18); the gas turbine assembly (1) being provided with a control device (8) configured to control the combustor assembly (4) on the basis of at least one parameter (Ppl) indicative of the pressure of the air measured in the plenum (3).