Varying Radius Nozzle Casing for Steam Turbine Flow Control
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Solution Overview
Problem
Current steam turbines experience flow losses and inefficiencies due to a non-adjustable bypass area between the nozzle casing and turbine casing, leading to suboptimal steam flow and reduced efficiency.
Innovation Solution
A nozzle casing component with a varying radius along its circumferential direction, featuring a flow deflecting surface and a radially inner surface, which creates a laminar bypass flow by varying the flow channel volume, preventing vortices and boundary layer separation, and allowing for improved steam flow distribution around the control wheel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a fixed small cavity is provided between the nozzle casing and turbine casing, then the structure is simple and easy to manufacture, but the steam flow is not optimized and flow losses occur
Solution Approach 1:
The nozzle casing is designed with an adjustable bypass area that can be modified depending on operating conditions. The bypass area between the nozzle casing and turbine casing can be adjusted to optimize steam flow under different load conditions, transforming a static structure into a dynamic one that adapts to varying operational requirements.
Solution Approach 2:
The invention changes the geometric parameters of the bypass area by providing adjustment elements that modify the gap between the nozzle casing and turbine casing. This allows the bypass area to be varied, optimizing steam flow characteristics and reducing flow losses under different operating conditions.
2Loss of energy
If the bypass area is increased to improve steam flow, then flow losses are reduced, but the structural stability and strength may be compromised
Solution Approach 1:
The adjustment mechanism is segmented into discrete elements that can be independently positioned. This segmentation allows for precise control of the bypass area while maintaining structural integrity, as the adjustment elements can be designed to distribute loads and maintain strength even when the bypass area is enlarged.
Solution Approach 2:
The dynamic adjustment capability allows the bypass area to be optimized for steam flow only when needed, while maintaining a smaller, structurally stronger configuration when flow optimization is less critical. This dynamic adaptation resolves the contradiction between flow efficiency and structural strength.
3Loss of energy
If the nozzle casing is designed with varying radius to optimize steam flow, then flow disturbances are reduced, but manufacturing complexity increases
Solution Approach 1:
The nozzle casing incorporates a varying radius design with curved surfaces that guide steam flow smoothly through the bypass area. This curvature eliminates sharp edges and corners that would cause flow disturbances, vortices, and boundary layer separation, thereby reducing energy losses while maintaining manufacturability through standard forming processes.
4Productivity
If the bypass area is made adjustable to optimize steam flow under different load conditions, then efficiency is improved, but device complexity and maintenance difficulty increase
Solution Approach 1:
The adjustment mechanism is divided into discrete, modular elements that can be independently accessed and maintained. This segmentation simplifies maintenance procedures, as individual adjustment elements can be inspected, adjusted, or replaced without disassembling the entire nozzle casing structure.
Solution Approach 2:
The adjustment mechanism is designed to be operable by the operator without requiring specialized tools or extensive technical knowledge. The self-service design allows operators to optimize the bypass area for different load conditions during routine operation, reducing the need for professional maintenance intervention.
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 enhances steam turbine efficiency by reducing flow disturbances, maintaining stability and strength, and allowing for easier manufacturing and maintenance, while optimizing steam flow through the bypass, even in low load conditions.
Implementation Method 1
The design enhances steam turbine efficiency by reducing flow disturbances, maintaining stability and strength, and allowing for easier manufacturing and maintenance, while optimizing steam flow through the bypass
Implementation Method 2
preventing vortices and boundary layer separation
Data Source
Figure 1
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Figure 4~5
AI summary
The present invention relates to a nozzle casing component (100) for a steam turbine (600), comprising a first section (110) extending along a circumferential direction (190) of the steam turbine (600), and a second section (120) extending along the circumferential direction (190) of the steam turbine (600). The first section (110) comprises a flow channel (111) and an outlet (112) configured such that a first inlet steam flow (653) flowing through the flow channel (111) is injectable through the outlet (112) into a flow path (140) of the steam turbine (600) upstream of a control wheel (791). The second section (120) comprises a flow deflecting surface (121) and a radius defined between the flow deflecting surface (121) and a rotation axis (180) of the steam turbine (600). The nozzle casing component (100) is arrangeable in a turbine casing (611) comprising a radially inner surface (623) and a further flow channel (629) is formable in-between the flow deflecting surface (121) and the radially inner surface (623). Furthermore, a second inlet steam flow (656) of the steam turbine (600) is guidable along the flow deflecting surface (121) such that the second inlet steam flow (656) enters the flow path (140) of the steam turbine (600) downstream of the control wheel (791). A length of the radius varies along the second section (120) in the circumferential direction (180) such that a volume of the further flow channel (629) varies depending on the variation of the length of the radius.