Extraction Steam Turbine Grid Valve for Part-Load Steam Bypass
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Solution Overview
Problem
Current extraction valve designs for steam turbines in process industries suffer from low efficiency during part-load operations, leading to suboptimal thermal performance and higher specific steam consumption.
Innovation Solution
A modified grid valve design with a rotatable disk and stationary disk, featuring inner and outer circular pockets that create bypass openings to guide steam efficiently, reducing energy losses and improving flow guidance through the turbine stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional extraction valve designs are used, then the turbine can operate at part-load, but thermal efficiency deteriorates and specific steam consumption increases
Solution Approach 1:
The grid valve is divided into two separate disks (rotatable disk and stationary disk) with distinct functional zones. The rotatable disk controls inner circular pockets for RK bypass, while the stationary disk controls outer circular pockets for Inner bypass. This segmentation allows independent control of different steam flow paths, enabling optimized part-load operation without compromising thermal efficiency.
2Ease of operation
If conventional grid valve design is used, then steam flow can be controlled, but steam energy losses increase due to poor flow guidance
Solution Approach 1:
Different regions of the grid valve are designed with specialized flow guidance characteristics. The inner circular pockets in the rotatable disk provide optimized guidance for steam entering rotor blades, while the outer circular pockets in the stationary disk provide optimized guidance for steam bypassing the blade group. Each region's geometry is tailored to its specific flow control function, minimizing energy losses locally and globally.
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 new design enhances thermal efficiency and reduces specific steam consumption by optimizing steam energy utilization at part loads, offering a more economical and efficient solution compared to existing solutions.
Implementation Method 1
the rotatable disk and the stationary disk have several pockets which are distribute on an inner circular and which can be brought, by rotating the rotatable disk, to overlap and builds first openings which guide the steam into rotor blades
Implementation Method 2
the flow going through GBC passages bypassing blade group which is next to pockets is called Inner bypass
Data Source
Figure 1~2
Figure 3
Figure 4a~4c
AI summary
The invention regards to Extraction steam turbine (1), comprising a grid valve (2) for controlling a steam throughput, wherein the grid valve (2) is mounted behind an extraction zone (3) which is located between a high-pressure stage (4) and a low-pressure stage (5), wherein the high-pressure stage (4) is fixed at a first guide blade carriers (6) and the low-pressure stage (5) is fixed at a second guide blade carriers (7) wherein the grid valve (2) consists of a rotatable disk (8) and a stationary disk (9) and is fixed at the second guide blade carrier (7) wherein the rotatable disk (8) and the stationary disk (9) have several inner pockets (10) which are distribute on an inner circular (11) and which can be brought, by rotating the rotatable disk (8), to overlap and builds first openings (12) which guide the steam into rotor blades (13) which are next downstream the grid valve (2) The rotatable disk (8) and the stationary disk (9) have several outer pockets (14) which are distribute on an outer circular (15) and which can be brought, by rotating the rotatable disk (8), to overlap and builds second openings (16) which guide the steam through third openings (17) which are create with the same patter as the pockets (14) in the grid valve (2), on the outer circular (15,) whereby the third openings (17) are part of an cannel (18) in the second guide blade carrier (7), bypassing the rotor blades (13) which are next downstream the grid valve (2).