Gas Turbine Combustor Liner Openings for Wake Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of wakes behind dilution openings in gas turbine engine combustors leads to higher NOx emissions and reduced durability of the combustor liner due to localized high temperatures and inadequate lateral spread of dilution air.
Innovation Solution
Incorporation of primary and secondary wake suppression dilution openings, along with wake flow suppressors, to enhance the lateral spread of dilution air and suppress wake formation, thereby improving the quenching of combustion gases and reducing NOx emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If dilution openings are provided in the combustor liner to cool combustion gases, then the turbine section is protected from excessive heat, but wake formation behind the openings causes localized high temperatures and increased NOx emissions
Solution Approach 1:
The dilution openings are divided into two distinct types: primary dilution openings for main cooling function, and secondary wake suppression dilution openings positioned downstream to eliminate wake formation. This segmentation allows each opening type to perform its specific function without interfering with the other, solving the contradiction between cooling effectiveness and wake-induced NOx emissions
Solution Approach 2:
The secondary wake suppression dilution openings act as an intermediary element that addresses the harmful wake effect generated by the primary openings. By introducing additional dilution air through these secondary openings, the wake is suppressed and lateral mixing is enhanced, thereby reducing NOx emissions while maintaining the primary cooling function
2Reliability
If dilution openings are used to quench combustion gases, then turbine protection is achieved, but lateral spread of dilution air is inadequate leading to localized high temperatures
Solution Approach 1:
The secondary wake suppression dilution openings are positioned downstream of the primary openings and oriented to provide lateral flow of dilution air. This dimensional approach transforms the primarily axial flow from single openings into a three-dimensional mixing pattern, enhancing lateral spread and eliminating localized high temperature zones while maintaining turbine protection
3Temperature
If primary dilution openings are provided for cooling, then combustion gas temperature is reduced, but wake formation reduces mixing efficiency and increases emissions
Solution Approach 1:
The secondary wake suppression dilution openings are positioned downstream of the primary openings to preemptively address the wake formation issue. By placing these secondary openings in advance of where the wake would fully develop, the system prevents the harmful effects before they occur, maintaining high mixing efficiency throughout the combustion chamber
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 solution effectively reduces NOx emissions and enhances the durability of the combustor liner by ensuring better mixing and cooling of combustion gases, thus improving the overall performance of the gas turbine engine.
Implementation Method 1
respective ones of the plurality of secondary wake suppression dilution openings being arranged adjacent to respective ones of the primary dilution openings to provide the flow of the secondary dilution air to suppress the wake formed in the flow of the primary dilution air
Implementation Method 2
The dilution air acts to quench hot combustion gases within the combustion chamber before the hot combustion gases flow into a turbine section of the gas turbine engine
Data Source
AI summary
A combustor for a gas turbine includes an outer casing, an inner casing, and an outer liner and an inner liner defining a combustion chamber. At least one of the outer liner or the inner liner includes (a) a plurality of primary dilution openings extending therethrough to provide a flow of primary dilution air into the combustion chamber, and (b) a plurality of secondary wake suppression dilution openings extending therethrough to provide a flow of secondary dilution air into the combustion chamber, respective ones of the plurality of secondary wake suppression dilution openings being arranged adjacent to respective ones of the primary dilution openings to provide the flow of the secondary dilution air to suppress a wake formed in the flow of the primary dilution air at a downstream side of the primary dilution openings.