Single-Casing Steam Turbine Double-Flow Exhaust Design
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Solution Overview
Problem
High-power steam turbines with single-casing configurations face challenges in maintaining blade strength due to increased blade length, making it difficult to implement single-casing and single-flow exhaust designs effectively, especially in high-output applications.
Innovation Solution
A steam turbine facility with a rotor shaft, radial bearings, and blade rows arranged to accommodate high-pressure, intermediate-pressure, and low-pressure turbines within a single casing, implementing a double-flow exhaust type and using a branched channel to distribute steam flow between low-pressure turbine blade rows, which reduces the need for connecting pipes and bearings, simplifies configuration, and maintains blade strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-casing configuration is adopted to simplify the steam turbine structure and reduce installation space, then device complexity and installation space are reduced, but blade length increases making it difficult to ensure blade strength
Solution Approach 1:
The low-pressure turbine is divided into two separate flow paths (first low-pressure turbine and second low-pressure turbine) that process steam in parallel. This segmentation allows each blade row to handle a portion of the total steam flow, preventing excessive blade length while maintaining the single-casing compact structure.
Solution Approach 2:
The patent transitions from a single-flow axial arrangement to a double-flow configuration where steam is split into two parallel paths. This dimensional change in flow arrangement allows the turbine to accommodate high-power requirements without increasing individual blade length excessively, resolving the strength issue while maintaining structural simplicity.
2Device complexity
If a single-flow exhaust type low-pressure turbine is used in a single-casing configuration, then device complexity is reduced, but blade length must be increased to handle high volume flow rate, making it difficult to ensure blade strength
Solution Approach 1:
The low-pressure turbine stage is segmented into two parallel flow paths with separate blade rows (first low-pressure turbine blade row and second low-pressure turbine blade row). Each blade row handles approximately half the steam volume flow rate, allowing shorter blade lengths that can maintain structural strength while still achieving high total power output.
Solution Approach 2:
The patent changes from a single-dimensional sequential flow to a two-dimensional parallel flow arrangement. By splitting the steam flow into two concurrent paths that pass through different blade rows, the system handles high volume flow rates without requiring excessively long blades, thus maintaining blade strength.
3Strength
If separate casings are used for high-pressure/intermediate-pressure turbine and low-pressure turbine, then blade strength can be maintained with shorter blades, but device complexity and installation space increase due to connecting pipes and additional bearings
Solution Approach 1:
The patent merges the high-pressure turbine, intermediate-pressure turbine, and low-pressure turbines into a single integrated casing. The double-flow low-pressure turbine configuration allows all components to be housed together without requiring external connecting pipes or additional bearings between casings, simplifying the overall structure while maintaining blade strength through the segmented flow paths.
Solution Approach 2:
While merging all turbine stages into one casing, the patent segments the low-pressure steam flow into two parallel paths internally. This internal segmentation allows the low-pressure blades to remain relatively short and strong, while the external single-casing structure eliminates the need for connecting pipes and inter-casing bearings.
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 configuration allows for high-output steam turbines with reduced facility costs by simplifying the setup, maintaining blade strength, and improving efficiency by balancing steam flow and reducing heat dissipation.
Implementation Method 1
a high-pressure turbine blade row 22, an intermediate-pressure turbine blade row 24, and a pair of low-pressure turbine blade rows 26A, 26B disposed on a rotor shaft 28
Data Source
AI summary
A steam turbine facility includes a rotor shaft, a pair of radial bearings for rotatably supporting the rotor shaft, a pair of low-pressure turbine blade rows disposed on the rotor shaft in a bearing span of the pair of radial bearings, and a high-pressure turbine blade row and an intermediate-pressure turbine blade row disposed on the rotor shaft in the bearing span and positioned between the pair of low-pressure turbine blade rows.