Fuel Gas Nozzle Vortex Mixing for Microturbine Combustion
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Solution Overview
Problem
Conventional fuel gas nozzles in microturbines suffer from poor air-fuel mixing homogeneity, leading to larger flame sizes and limited microturbine size reduction, as well as an inability to adjust air-fuel ratios for different fuel types, resulting in inefficient combustion and increased complexity.
Innovation Solution
A fuel gas nozzle design featuring a first and second chamber, a pilot and main fuel gas pipe, an intake pipe with a non-intersecting centerline to induce a vortex flow, and a distributor with inclined blades to enhance mixing, along with a flow control valve to adjust air-fuel ratios, ensuring complete mixing and efficient combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If air flows into the mixing chamber through intake openings along a single direction, then the structure is simple, but the homogeneity in mixing of air and fuel gas deteriorates
Solution Approach 1:
The patent employs asymmetric guiding plates with different angles arranged at different positions around the mixing chamber. These guiding plates are not uniformly distributed but positioned strategically to create multiple vortex flows from different directions, transforming the simple single-direction flow into a complex multi-directional vortex pattern that enhances mixing homogeneity while maintaining structural simplicity.
2Reliability
If the combustion chamber size is determined by flame length to prevent burnout, then safety is ensured, but the microturbine size cannot be reduced
Solution Approach 1:
The patent implements preliminary mixing action before the fuel-gas-air mixture enters the combustion chamber. By using guiding plates to pre-create vortex flows and achieve homogeneous mixing in the mixing chamber, the combustion process becomes more efficient and compact. This preliminary preparation allows for a shorter flame length and smaller combustion chamber while maintaining safe operation, thereby reducing the overall microturbine size.
3Ease of manufacture
If a fixed size opening is used for air intake, then manufacturing is simple, but the air-fuel ratio cannot be adjusted for different fuel types
Solution Approach 1:
The patent replaces the fixed-size opening with adjustable flow control valves that can dynamically regulate the air intake quantity. These valves allow the system to adapt to different fuel types (methane, propane, biogas, wood gas) by adjusting the air-fuel ratio according to each fuel's specific combustion requirements, transforming a static manufacturing-simple design into a dynamic, versatile system.
4Device complexity
If guiding plates are placed at the leeward side, then air intake is simplified, but the vortex flow field induction deteriorates
Solution Approach 1:
The patent transitions from simple planar guiding plates to three-dimensional spiral guiding plates that extend along the axial direction of the mixing chamber. This dimensional enhancement creates stronger vortex flows by introducing rotational motion in addition to the radial inward flow, thereby improving vortex flow field quality while maintaining the simplicity of the air intake structure through the leeward-side 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
The design achieves improved air-fuel mixing, reducing flame length and microturbine size, allowing for adjustable air-fuel ratios for various fuels, enhancing combustion efficiency and enabling smaller, more versatile microturbine designs suitable for green energy applications.
Implementation Method 1
A centerline of the intake pipe is not intersected with a centerline of the second chamber, so as to induce a vortex flow field of the air flowing into the mixing zone for mixing the air and the second fuel gas
Implementation Method 2
the distributor includes a plurality of inclined blades to induce a vortex flow field of the second fuel gas flowing into the mixing zone opposite to the vortex flow field of the air flowing into the mixing zone
Data Source
AI summary
A fuel gas nozzle used in a microturbine includes a first chamber, a second chamber connected to the first chamber, a pilot fuel gas pipe, a main fuel gas pipe and an intake pipe. An intake zone and a mixing zone are respectively formed in the first chamber and the second chamber and are communicated with each other. The pilot fuel gas pipe is for introducing a first fuel gas into a downstream of the second chamber. The main fuel gas pipe is for introducing a second fuel gas into the mixing zone via the intake zone. The intake pipe is for introducing an air into the mixing zone. A centerline of the intake pipe is not intersected with a centerline of the second chamber, so as to induce a vortex flow field of the air flowing into the mixing zone for mixing the air and the second fuel gas.