Combustor Cylinder Cooling Paths to Prevent Hot Gas Backflow
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Solution Overview
Problem
The combustor cylinder in gas turbines is prone to damage due to backflow of high-temperature combustion gas into cooling flow paths, caused by dynamic pressure loss and subsequent static pressure rise when the gas collides with the air supply pipe, leading to potential burning of the barrel.
Innovation Solution
The combustor cylinder design includes a barrel with separate cooling flow paths and an air supply pipe, featuring impingement circumvention flow paths that avoid forming outlets within the static pressure rise region, along with a burner configuration that swirls fuel and air to manage collision angles, preventing backflow and enhancing cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling flow path outlets are formed in the edge of the insertion opening to cool the barrel, then cooling efficiency is improved, but combustion gas may flow back into the cooling flow path causing the barrel to be burnt
Solution Approach 1:
The patent applies local quality by differentiating the functions of different cooling flow paths. Opening circumference flow paths are specifically designed to cool the insertion opening edge by having their outlets positioned away from the static pressure rise region, while other cooling flow paths can have outlets in the static pressure rise region to maximize cooling effect. This localized functional differentiation resolves the contradiction between cooling efficiency and preventing gas backflow.
Solution Approach 2:
The cooling flow paths are segmented into different types based on their outlet positions relative to the static pressure rise region. By dividing the cooling system into opening circumference flow paths (with outlets outside the static pressure rise region) and other cooling flow paths (with outlets inside the static pressure rise region), the patent enables each segment to serve its specific function optimally, preventing backflow while maintaining cooling efficiency.
2Productivity
If air supply pipe protrudes into the combustion space to supply secondary air, then combustion efficiency is improved, but static pressure rise causes combustion gas to flow back into cooling flow paths
Solution Approach 1:
The patent applies local quality by positioning the air supply pipe's insertion depth and the cooling flow path outlets at different locations. The air supply pipe protrudes into the combustion space to supply secondary air effectively, while the cooling flow path outlets are strategically positioned to avoid the static pressure rise region caused by gas collision with the air supply pipe, thus preventing backflow while maintaining combustion efficiency.
Solution Approach 2:
The opening circumference flow paths act as an intermediary system that bridges the need for air supply and the need to prevent backflow. By creating a dedicated cooling flow path configuration that circumvents the static pressure rise region, the patent mediates between the air supply function and the backflow prevention requirement.
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 improves the durability of the combustor cylinder by effectively preventing combustion gas backflow and maintaining structural integrity, thus enhancing the overall performance and longevity of the gas turbine system.
Implementation Method 1
a plurality of cooling flow paths through which a cooling medium flows extending between the inner peripheral surface and the outer peripheral surface in a direction along the inner peripheral surface
Implementation Method 2
When the combustion gas collides with the air supply pipe, while a dynamic pressure thereof is lowered, a static pressure thereof rises
Data Source
AI summary
A cylinder for combustion comprises a barrel having a cylindrical shape, and an air supply pipe. An insertion opening and a plurality of cooling flow paths are formed in the barrel. Collision region flow paths of the plurality of cooling flow paths each have a collision region circumvention flow path part intersecting with a collision gas axis extending in the direction of the flow of combustion gas moving toward a pipe center axis of the air supply pipe. The collision region circumvention flow path parts have an upstream-side direction component from the collision gas axis along the edge of the insertion opening, and have a downstream-side direction component from the collision gas axis along the edge of the insertion opening. No exit is formed in a portion of the collision region circumvention flow path parts within the range of specified angles about the pipe center axis.