Fuel Spray Nozzle Jet Flow Atomization
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Solution Overview
Problem
Conventional fuel spray nozzles in gas turbine combustion systems face challenges in achieving uniform atomization of fuel droplets due to non-uniform air and fuel flow characteristics, leading to suboptimal combustion performance.
Innovation Solution
The fuel spray nozzle design includes a swirler with vanes that produce a jet flow and turbulent wake, with the liquid fuel being directed primarily to areas on the prefilming surface that receive the jet flow, rather than the wake, to achieve a more uniform droplet size distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional spray nozzles are used with standard swirler and fuel circuit configuration, then the system can deliver fuel to prefilmer surfaces, but the atomisation is non-uniform due to non-uniform air and fuel flow characteristics
Solution Approach 1:
The invention applies local quality by directing fuel to specific locations on the prefilmer surface corresponding to jet flow regions rather than wake regions. The fuel apertures are strategically positioned and angled to deliver fuel locally where jet flow occurs, creating non-uniform fuel distribution that compensates for non-uniform air flow, thereby achieving uniform droplet size distribution at the trailing edge.
Solution Approach 2:
The invention employs preliminary action by pre-positioning fuel apertures and deflectors to direct fuel toward jet flow areas before the air-fuel mixing occurs. The fuel is delivered in advance to specific locations on the prefilmer surface where it will be atomized by jet flow, ensuring optimal mixing conditions are established prior to atomization.
2Manufacturing precision
If fuel is distributed uniformly across the prefilmer surface, then the system is simple to operate, but the non-uniform wake regions cause non-uniform atomisation
Solution Approach 1:
The invention transitions from uniform fuel distribution to non-uniform local fuel distribution. Fuel is concentrated in jet flow regions through specifically positioned apertures and deflectors, creating local quality variations that compensate for air flow non-uniformity. This results in uniform atomization despite the non-uniform fuel distribution strategy.
3Manufacturing precision
If the swirler produces strong jet flow for good atomisation, then the wake regions become more turbulent and harmful to uniform atomisation
Solution Approach 1:
The invention converts the harmful effect of wake turbulence into a benefit by strategically positioning fuel apertures and deflectors to direct fuel away from wake regions and toward jet flow regions. The non-uniform fuel distribution pattern, combined with the swirler's jet-wake structure, ensures that fuel is atomized primarily in jet flow regions where atomization is more uniform, thereby converting the presence of wakes into an opportunity for optimized fuel placement.
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 design enhances the uniformity of droplet size distribution at the trailing edge of the prefilming surface, resulting in improved combustion performance by optimizing the fuel atomization process.
Implementation Method 1
the swirler produces a jet flow of gas from between adjacent vanes
Implementation Method 2
a turbulent flow of gas in the wake of each vane
Implementation Method 3
the air flow shears the film towards the trailing edge of the prefilmer surface causing the disintegration of the fuel film into fine droplets
Data Source
AI summary
A fuel spray nozzle, for atomising liquid fuel in gas, including: an gas passage; a liquid fuel passage; a swirler provided in the gas passage and including vanes such that, when gas passes through the gas passage, the swirler produces a jet flow of gas from between adjacent vanes and a turbulent flow of gas in the wake of each vane; a prefilming surface for receiving liquid fuel from the liquid fuel passage, and gas from the gas passage, wherein the prefilming surface includes areas that receive jet flow of gas from the gas passage, in use; wherein the fuel spray nozzle is configured to direct the liquid fuel passing through the liquid fuel passage to the areas on the prefilming surface that receive a jet flow of gas from the gas passage.