Combustor Liner Shaft Fuel Injection for Compact Altitude Relight
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Solution Overview
Problem
Small gas turbine engines face challenges with combustor designs that limit altitude relight capabilities, reverse flow designs that decrease energy recovery, and fuel injection systems that require larger packages and separate pumps, along with ignitor positioning that results in undesirably long combustors.
Innovation Solution
A gas turbine engine design featuring a toroidal recirculation zone, rapid quench zone, and lean combustion zone with integrated ignitor, utilizing a shaft to transmit energy and pump fuel, and a shaft cooling air pump for enhanced cooling and compact packaging, allowing for additive manufacturing construction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional fuel injection systems with separate pumps are used, then fuel can be delivered to the combustor, but the engine package size increases and complexity increases
Solution Approach 1:
The patent combines the fuel pump function directly into the combustor assembly, eliminating the need for a separate fuel pump component. The combustor is designed with integrated fuel injection capability, merging two previously separate functions (combustion and fuel pumping) into a single integrated unit, thereby reducing overall package size and system complexity
Solution Approach 2:
The combustor assembly is designed to perform multiple functions: it serves as both the combustion chamber and the fuel pumping mechanism. The integrated design allows the same component structure to handle both air-fuel mixing and fuel pressurization, making the system more versatile and reducing the number of dedicated components needed
2Length of stationary object
If reverse flow combustor design is used, then combustor length can be reduced, but energy recovery decreases
Solution Approach 1:
The patent employs a toroidal (doughnut-shaped) recirculation zone within the combustor, utilizing curved flow paths to maintain compact dimensions. The toroidal geometry allows the combustion gases to recirculate in a curved manner, achieving short combustor length while preserving energy through the curved flow pattern that maintains thermal energy within the compact volume
3Reliability
If ignitor is positioned at the end of the combustor, then ignition can be achieved, but combustor length increases
Solution Approach 1:
The ignitor is nested within the toroidal recirculation zone rather than being positioned at the combustor exit. This nested arrangement allows the ignitor to be housed inside the existing combustion flow structure, achieving reliable ignition within the recirculating hot zone while avoiding the need to extend the combustor length to accommodate a separate ignitor housing
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
The design achieves improved operability, flame stability, and compact size with high altitude relight capability, enhanced durability, and efficient energy recovery through supercharged cooling and integrated fuel injection.
Implementation Method 1
The shaft, which connects the turbine to the compressor through an annulus formed by the combustor surrounding the shaft, is configured to transmit rotational energy from the turbine to the compressor to power the compressor
Implementation Method 2
A shaft cooling air pump is configured to further compress and accelerate the second portion of the compressed air before the second portion of the compressed air enters the combustor as fuel injector air and combustor secondary inlet air
Implementation Method 3
a cooling air flow path configured to direct a second portion of the compressed air around an outer combustor liner to cool the combustor liner
Implementation Method 4
The rapid quench zone, which includes an array of quench tubes, is configured to receive and quench with quench air combustion products from the rich combustion zone
Implementation Method 5
The combustor includes a toroidal recirculation zone configured to receive and combust fuel in a rich combustion zone
Implementation Method 6
The lean combustion zone is configured to complete combustion of the fuel and to generate hot combustor exhaust gas
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A gas turbine engine (100a) includes a compressor (102), a combustor (104) positioned fluidically and physically downstream of the compressor (102), a turbine (108) positioned downstream of the combustor (104), and a shaft (110) mechanically connecting the turbine (108) and the compressor (102). The combustor (104) is fluidically connected to the compressor (102) to receive a first portion of the compressed air (130) as combustor primary inlet air (130a). The combustor (104) includes a toroidal recirculation zone configured to receive and combust fuel in a rich combustion zone (104a), an ignitor (118) positioned to ignite an air/fuel mixture in the rich combustion zone (104a), a rapid quench zone (104b) downstream of the toroidal recirculation zone, a lean combustion zone (104c) downstream of the rapid quench zone (104b), and a cooling air flow path (124) configured to direct a second portion (130b) of the compressed air (130) around an outer combustor liner (140).