Exhaust Casing Guiding Rib Merging for Steam Turbines
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Solution Overview
Problem
Conventional exhaust systems for low-pressure steam turbines experience significant pressure losses and reduced efficiency due to the formation of vortices caused by numerous collisions of steam with guiding ribs and reinforcement elements within the inner space of the exhaust casing, leading to decreased performance.
Innovation Solution
The configuration of a guiding rib and reinforcement elements within the exhaust casing is optimized to reduce the number of elements in the inner space, with the guiding rib serving as both a guide and a reinforcement element, positioned to minimize steam collisions and pressure losses, and eliminating the need for separate fastening ribs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If separate fastening ribs and reinforcement elements are used to connect casing blocks and provide structural reinforcement, then the structural strength and reliability of the exhaust casing is improved, but the number of elements in the inner space increases, causing more steam collisions and pressure losses
Solution Approach 1:
The patent combines the fastening rib and reinforcement element into a single integrated component. The fastening rib is designed with reinforcement structures that provide both structural support and connection functionality, eliminating the need for separate reinforcement elements. This merging reduces the number of components in the inner space, thereby reducing steam collisions and pressure losses while maintaining structural strength.
Solution Approach 2:
The fastening rib is designed to perform multiple functions simultaneously: it connects the casing blocks together, provides structural reinforcement to withstand vacuum pressures, and guides steam flow. By making the fastening rib multi-functional, the patent eliminates the need for separate dedicated reinforcement elements, thus reducing energy losses from steam collisions.
2Reliability
If multiple separate elements (guiding ribs, fastening ribs, reinforcement elements) are positioned within the inner space, then the structural integrity and guiding function are improved, but the steam flow efficiency deteriorates due to increased collisions and vortex formation
Solution Approach 1:
The patent merges the guiding rib and fastening rib into a single integrated component. The guiding rib is designed with fastening structures that allow it to perform both steam flow guidance and structural connection functions. This reduces the total number of elements in the inner space, minimizing steam collisions and vortex formation while maintaining structural integrity and guiding effectiveness.
Solution Approach 2:
The guiding rib is designed to perform multiple functions: it guides the steam flow to prevent backflow, provides structural connection between casing blocks, and offers reinforcement. By making the guiding rib multi-functional, the patent eliminates separate fastening ribs and reduces overall element count, thereby improving steam flow efficiency while maintaining reliability.
3Ease of operation
If conventional separate guiding blocks and reinforcement elements are used, then the structural support and flow guidance functions are achieved, but the device complexity increases and steam collisions increase leading to higher pressure losses
Solution Approach 1:
The patent combines the guiding block and reinforcement element into a single integrated guiding rib structure. This unified component provides both flow guidance and structural support functions that were previously performed by separate elements. The reduction in element count simplifies the device complexity while maintaining ease of operation for steam flow guidance.
Data Source
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AI summary
The present invention relates to the exhaust casing (10) for a low pressure steam turbine system comprising an upper wall (11) and a side wall (12), an inner surface (13) and an outer surface (14), a plurality of casing reinforcement elements (15), and a guiding rib (17), wherein the guiding rib (17) is attached to the inner surface (13) of the upper wall (11) of the exhaust casing (10) and extending radially inwards, and wherein each of the casing reinforcement elements (15) is fastened to the guiding rib (17). The guiding rib serves as a guide for a steam moving in the substantially vertically upward direction to be turned in 180 degrees in order to flow downwards to the outlet of the exhaust system. The guiding rib further serves as a fastening element for fastening the reinforcement elements to the upper wall of the exhaust casing and may also serve as a connecting element between casing blocks. The steam flow efficiency is improved with this configuration, because it reduces the number of elements within the inner space of the exhaust casing. Thus, collisions of the steam passing through the system with said elements are reduced as well. Consequently, turbulent velocities of the steam are balanced and pressure losses caused by the collisions are reduced. As a result, the efficiency of the exhaust system and the overall performance of the turbine are improved.