Gas Turbine Fuel Flow Bias Correction for Humidity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engines face performance and durability issues due to varying combustion dynamics caused by unchecked air humidity fluctuations, leading to premature wear and emissions problems.
Innovation Solution
A system and method that adjusts fuel-flow splits in gas turbine engines by determining evaporation cooler and relative humidity corrections, using look-up tables and sensors to set bias values for fuel circuits, maintaining combustion dynamics and emissions performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel-flow splits are adjusted to compensate for elevated inlet air humidity, then combustion dynamics and emissions are maintained, but device complexity increases due to additional sensors and control logic
Solution Approach 1:
The control system continuously monitors inlet air humidity using a humidity sensor and adjusts fuel-flow splits in real-time based on the measured humidity levels. This closed-loop feedback mechanism maintains stable combustion dynamics by compensating for humidity variations without requiring manual intervention or complex mechanical modifications.
Solution Approach 2:
The patent replaces complex mechanical adjustment mechanisms with an electronic control system that uses sensor data and automated calculations to adjust fuel-flow splits. This substitution of mechanical systems with electronic control reduces moving parts while achieving the same combustion stability objective.
2Object-generated harmful factors
If humidity correction is implemented for all operating conditions, then emissions performance is maintained, but loss of time occurs due to additional measurement and calculation steps
Solution Approach 1:
The control system pre-calculates bias values for different humidity conditions and stores them in lookup tables. When humidity changes are detected, the system can quickly retrieve and apply the appropriate bias value without performing complex real-time calculations, thereby maintaining emissions performance while minimizing response time delay.
3Object-generated harmful factors
If multiple fuel circuits are used to minimize NOx emissions and combustion dynamics, then emissions are reduced, but device complexity increases due to multiple fuel circuits and fuel-flow split management
Solution Approach 1:
The patent adjusts the fuel-flow split parameters across multiple fuel circuits based on inlet air humidity conditions. By changing the distribution parameters of fuel flow among the circuits rather than modifying the physical circuit structure, the system maintains low NOx emissions while managing complexity through software-based parameter adjustment rather than hardware complexity.
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 enhances the reliability and durability of gas turbine engine components, reduces maintenance, and stabilizes emissions by dynamically adjusting fuel flow based on inlet air conditions.
Implementation Method 1
determining whether an evaporation cooler is actively importing water content into the air entering an inlet of a compressor
Implementation Method 2
determining whether the relative humidity is greater than a predefined threshold (e.g., average humidity of a dry day at 60%)
Data Source
AI summary
Methods for controlling a gas turbine engine are provided, where a compressor inlet temperature, ambient temperature, and relative humidity are measured. Utilizing these measurements, it is first determined whether an evaporation cooler is actively importing water content into inlet air entering the compressor. This determination is based on whether the inlet air is substantially cooler than the ambient temperature. If so, an EC correction factor is added to an inlet air temperature value (CTIM) and set as an air temperature parameter (INLETIM). Second, it is determined whether the relative humidity is greater than a predefined threshold. If so, a relative humidity (RH) correction factor is added to CTIM and set as the INLETIM. Next, the INLETIM and TTRF are located in a look-up table, and a bias value corresponding to these inputs is identified. The fuel-flow for a fuel circuit is adjusted according to the identified bias value.