Grid Valve Magnetic Repulsion for Steam Turbine Actuation
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Solution Overview
Problem
Conventional multi-stage steam turbines face inefficiencies due to the simultaneous passage of steam through all nozzles, leading to throttling effects and increased actuating forces required to operate the annular grid valve, which reduces steam delivery to downstream stages sequentially and increases mechanical demands.
Innovation Solution
The proposed grid valve design incorporates an annular stationary and rotatable plate with magnets on their surfaces, allowing for sequential steam passage through differently sized sets of holes, reducing the force required to rotate the valve and minimizing throttling effects by utilizing magnetic repulsion to counteract differential pressure forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If all stationary plate holes and rotatable plate holes overlap simultaneously to allow steam passage, then steam flow rate increases, but throttling effects occur and efficiency decreases
Solution Approach 1:
The grid valve divides the annular flow area into multiple discrete holes (stationary plate holes and rotatable plate holes) arranged in different circumferential positions. By rotating the rotatable plate, different combinations of holes can overlap to control steam flow distribution, enabling sequential delivery to different nozzle groups and reducing simultaneous throttling effects.
2Stability of the object's composition
If the annular grid valve is closed to hold steam at intermediate stage for extraction, then fixed pressure steam is obtained, but differential pressure force increases requiring larger actuating mechanism
Solution Approach 1:
The patent introduces a magnetic field generated by a magnet assembly to counteract the differential pressure force acting on the rotatable plate. The magnetic force provides an opposing force that balances the pressure differential, enabling the valve to maintain closed position for steam extraction without requiring a proportionally larger actuating mechanism.
Solution Approach 2:
The patent replaces part of the mechanical actuating system with a magnetic field-based force generation system. Instead of relying solely on mechanical actuators to overcome the full differential pressure force, a magnetic field is used to generate the necessary counteracting force, reducing the mechanical load on the actuating mechanism.
3Loss of energy
If sequential steam delivery through nozzle groups is implemented, then throttling effects are reduced, but complex hole arrangement and rotation control are required
Solution Approach 1:
The stationary plate holes and rotatable plate holes are arranged with different circumferential positions and patterns. This asymmetric arrangement allows selective overlapping of holes in different rotational positions, enabling sequential steam delivery to different nozzle groups. The asymmetric hole distribution creates different flow paths at different rotation angles, facilitating controlled sequential delivery.
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 enables sequential steam delivery to downstream stages, reducing throttling effects and lowering the actuating force needed, thereby enhancing the efficiency and mechanical simplicity of the steam turbine operation.
Implementation Method 1
a first magnet repels a second magnet
Data Source
AI summary
A grid valve may include an annular stationary plate having a first annular surface, and an annular rotatable plate disposed on the annular stationary plate and rotatable relative to the annular stationary plate. The annular rotatable plate may have a second annular surface, and each of the annular stationary plate and the annular rotatable plate may define a plurality of holes in the respective annular surfaces thereof. The grid valve may further include a first magnet disposed on the first annular surface and a second magnet disposed on the second annular surface such that the first magnet repels the second magnet.