Gas Turbine Burner Swirl Vane Design for Uniform Fuel Mixing
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Solution Overview
Problem
Conventional gas turbine combustion burners fail to thoroughly mix fuel and air to form a uniform concentration and uniformize flow velocity, leading to backfire issues.
Innovation Solution
A premixed combustion burner design featuring a fuel nozzle with swirl vanes on its outer peripheral surface, arranged to progressively curve and create a clearance between the vane and the burner tube, optimizing angles and aspect ratios to ensure uniform air flow and fuel concentration, with fuel injection holes positioned to prevent interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional combustors are used with swirlers in the inner tube, then the structure is simple, but the fuel and air cannot be thoroughly mixed to form uniform concentration
Solution Approach 1:
The patent applies local quality by providing swirl vanes only on the outer peripheral surface of the premixing fuel nozzle rather than throughout the entire inner tube. This localized approach creates effective swirl flow for mixing fuel and air at the critical mixing zone, achieving uniform fuel concentration without the complexity of full inner tube swirlers.
Solution Approach 2:
The invention transitions from the conventional two-dimensional swirler design (in the inner tube cross-section) to a three-dimensional arrangement by placing swirl vanes on the outer peripheral surface of the fuel nozzle. This dimensional change allows the swirl flow to wrap around the fuel injection zone, improving mixing efficiency and uniformity.
2Reliability
If conventional combustors are used, then the device structure is simple, but the flow velocity of fuel gas cannot be uniformized, leading to backfire
Solution Approach 1:
The patent places swirl vanes specifically on the outer peripheral surface of the fuel nozzle where the fuel injection occurs. This localized positioning creates a controlled swirl flow that uniformizes the fuel gas flow velocity at the point of combustion, preventing backfire without requiring complex modifications throughout the entire burner structure.
Solution Approach 2:
The swirl vanes are positioned on the fuel nozzle itself, performing the flow uniformization action before the fuel gas enters the combustion zone. This preliminary action ensures that the fuel and air are pre-mixed with uniform concentration and velocity, preventing backfire conditions from developing in the first place.
3Manufacturing precision
If swirl vanes are added to the fuel nozzle, then mixing performance improves, but the device complexity increases
Solution Approach 1:
The swirl vanes are provided only on the outer peripheral surface of the fuel nozzle, creating a localized mixing enhancement zone. This approach improves fuel-air mixing uniformity where it is most needed (at the injection point) without adding complexity to the entire fuel nozzle structure or requiring additional components throughout the combustor.
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 uniform fuel concentration and flow velocity, effectively preventing backfire while promoting efficient mixing of fuel and air through vortex flow, maintaining low pressure loss and assembly accuracy.
Implementation Method 1
swirl vanes which progressively curve from an upstream side toward a downstream side for swirling air flowing through the air passage from the upstream side toward the downstream side
Data Source
AI summary
A fuel nozzle 110 having a plurality of swirl vane 130 on an outer peripheral surface thereof is installed within a burner tube 120, with a clearance 121 being provided. Each swirl vane 130 progressively curves from an upstream side toward a downstream side (inclines along a circumferential direction) in order to swirl compressed air A flowing through an air passage 111 to form a swirl air flow a. Here, curvature of each swirl vane 130 is greater on its outer peripheral side than on its inner peripheral side. By suppressing occurrence of an air streamline heading from the inner peripheral side toward the outer peripheral side, therefore, flow velocity on the inner peripheral side and flow velocity on the outer peripheral side become equal, thus preventing flashback on the inner peripheral side.