Thrust Piston Balances Steam Turbine Axial Force
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Solution Overview
Problem
Steam turbine plants with an odd number of turbines face challenges in thrust force balancing, requiring large and costly thrust bearings, which are inefficient and only needed part-time, especially when one turbine is activated based on load requirements.
Innovation Solution
A thrust piston is configured to counteract the thrust force of a single-flow low-pressure turbine using high-pressure steam, with a cylindrical shape and seals to direct steam from the high-pressure turbine to a cavity adjacent to the single-flow low-pressure turbine, allowing for efficient balancing without the need for oversized thrust bearings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a large thrust bearing is used to balance the thrust force of a single-flow low-pressure turbine, then thrust balancing is achieved, but the cost and size of the thrust bearing increase significantly
Solution Approach 1:
A thrust piston is introduced as an intermediary component between the high-pressure turbine and the single-flow low-pressure turbine. This thrust piston receives high-pressure steam from the high-pressure turbine and converts it into axial thrust force to counterbalance the thrust force generated by the single-flow low-pressure turbine, thereby avoiding the need for a large thrust bearing
Solution Approach 2:
The invention utilizes pneumatic pressure from high-pressure steam to generate the counterbalancing thrust force. The high-pressure steam is directed into a cavity behind the thrust piston, creating pressure that pushes the piston to generate the required axial force to balance the turbine thrust, replacing the need for a mechanically complex thrust bearing
2Adaptability or versatility
If turbines are paired to balance thrust forces, then thrust balancing is achieved, but the system cannot accommodate an odd number of turbines for flexible load management
Solution Approach 1:
The thrust piston acts as a mediator that enables the single-flow low-pressure turbine to be operated independently without requiring a paired turbine for thrust balancing. This intermediary mechanism allows the system to accommodate an odd number of turbines while maintaining thrust balance and load management flexibility
3Reliability
If a thrust bearing is sized for peak load conditions, then thrust balancing is achieved during peak load, but the thrust bearing is oversized and only needed part-time
Solution Approach 1:
The thrust balancing system is made dynamic through the thrust piston that can actively respond to changing load conditions. The high-pressure steam supply to the thrust piston can be modulated to provide the exact amount of counterbalancing force needed at any given moment, rather than relying on a statically oversized thrust bearing
Solution Approach 2:
The high-pressure steam system serves multiple functions: it drives the high-pressure turbine for power generation and simultaneously provides the pressure needed to operate the thrust piston for thrust balancing. This multi-functionality eliminates the need for a dedicated oversized thrust bearing that would only be needed part-time
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 solution allows for cost-effective and efficient thrust balancing, reducing the size and maintenance needs of thrust bearings, while providing flexibility in load management by engaging and disengaging the single-flow low-pressure turbine as needed.
Implementation Method 1
high-pressure steam is supplied to a cavity behind the thrust piston
Data Source
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AI summary
A steam turbine power plant that includes a first steam turbine, the steam turbine power plant including: a thrust piston 128 operably connected to the first steam turbine via a shaft 102; and means for applying a supply of pressurized steam against the thrust piston 128 such that the thrust piston 128 applies a desired thrust force to the shaft 102. The desired thrust force may comprise a thrust force that partially balances a thrust force the first steam turbine applies to the shaft 102 during operation.