TAPS Combustor Airflow Split and CMC Liners
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Solution Overview
Problem
Traditional twin annular premixed swirler (TAPS) combustors in gas turbine engines face limitations due to a relatively low airflow split between the pilot swirler and main mixer, which restricts fuel injection and increases combustion dynamics, especially at high power operating conditions.
Innovation Solution
The combustor system features a higher pilot swirler airflow (greater than 14% of total airflow) and a lower main mixer airflow (less than 50% of total airflow), with a fuel nozzle design that allows a higher fuel ratio to the pilot fuel injector at high power conditions, utilizing ceramic matrix composite (CMC) materials for the liners to reduce cooling airflow needs and enhance temperature capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional TAPS combustors use low airflow in pilot swirler and high airflow in main mixer, then fuel injection is limited to pilot stage, but combustion dynamics increase at high power operating conditions
Solution Approach 1:
The patent changes the airflow distribution parameters by increasing pilot swirler airflow to greater than 14% of total airflow and decreasing main mixer airflow to less than 50% of total airflow. This parameter reversal enables fuel injection in both stages while reducing combustion dynamics at high power operating conditions.
Solution Approach 2:
The patent implements variable airflow split between pilot swirler and main mixer based on operating conditions. The system dynamically adjusts the airflow distribution to optimize combustion performance across different power levels, transitioning from pilot-stage dominated injection at low power to balanced multi-stage injection at high power.
2Temperature
If CMC materials are used for liners, then temperature capability increases and cooling airflow is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent employs ceramic matrix composite (CMC) materials for the inner and outer liners of the combustor. These CMC materials provide superior temperature capability, allowing the combustor to operate at higher temperatures with reduced cooling airflow requirements, thereby improving overall combustion efficiency.
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 configuration reduces combustion dynamics, improves fuel-air mixing, and decreases NOx emissions, enabling higher power operation with improved durability of combustor components and reduced smoke emissions, while maintaining high combustion efficiency.
Implementation Method 1
fuel is burned to input heat to the engine cycle. Typical combustors incorporate one or more fuel injectors whose function is to introduce liquid fuel into an air flow stream so that it can atomize and burn.
Implementation Method 2
The fuel nozzle includes a pilot swirler. The combustor system further comprises a main mixer attached to the outlet end of the fuel nozzle.
Implementation Method 3
improves fuel-air mixing
Implementation Method 4
fuel is burned to input heat to the engine cycle
Implementation Method 5
fuel is burned to input heat to the engine cycle
Implementation Method 6
Components fabricated from CMC materials have a higher temperature capability compared with typical components, e.g., metal components
Data Source
AI summary
Combustor systems are provided. For example, a combustor system comprises a combustor having forward and aft ends and including annular inner and outer liners that each extend generally along an axial direction and define a combustion chamber therebetween. The combustor system also comprises a fuel nozzle having an outlet defined in an outlet end of the fuel nozzle and including a pilot swirler. The outlet is positioned at the forward end of the combustor to direct a fuel-air mixture into the combustion chamber. The combustor system further comprises a main mixer attached to the outlet end of the fuel nozzle and extending about the outlet. A total combustor airflow through the combustor comprises a pilot swirler airflow that is greater than about 14% of the total combustor airflow and a main mixer airflow that is less than about 50% of the total combustor airflow.