Double Flow Turbine Rotor Cooling via Annular Steam Path
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Solution Overview
Problem
In double-flow steam turbines, stagnant steam between the rotor and the tub section causes high temperatures due to windage heating, potentially shortening the rotor's lifespan and leading to turbine failure.
Innovation Solution
A steam turbine design with a tub section between two parallel flow turbine ends, where a difference in reaction stages between the generator and turbine ends creates a pressure differential, urging steam flow through an annulus to cool the rotor, reducing its temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam flows radially inwardly toward the tub section in a double-flow steam turbine, then the steam flow divides and turns axially to flow in opposing directions to enter each of the two parallel flow turbine ends, but steam flow becomes stagnant between the rotor and the tub section resulting in high temperature on the rotor due to windage heating
Solution Approach 1:
The invention introduces an intermediary cooling steam flow path through the annulus between the rotor and tub section. This intermediate flow acts as a mediator to remove heat from the rotor surface, preventing the harmful effect of windage heating while maintaining the primary steam flow path for power generation.
Solution Approach 2:
The invention extracts a portion of the steam flow and directs it through a dedicated cooling path (annulus) separate from the main power generation path. This extracted steam flow is specifically used for cooling the rotor, removing the harmful thermal effect without interfering with the primary function of the turbine.
2Reliability
If high temperature occurs on the rotor due to stagnant steam and windage heating, then the useful life of the rotor is shortened and failure of the steam turbine may occur, but no additional cooling components are added to the turbine
Solution Approach 1:
The invention makes the existing steam flow path serve multiple functions: the annulus between the rotor and tub section, which is already present in the turbine structure, is utilized for both structural support and steam cooling. This multi-functional approach extends rotor lifespan without adding separate cooling components, maintaining structural simplicity.
Solution Approach 2:
The turbine system uses its own steam flow to cool the rotor. The steam that would otherwise be wasted or require separate handling is redirected through the annulus to provide self-cooling for the rotor, eliminating the need for external cooling systems and reducing overall device complexity.
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 solution effectively reduces the rotor temperature by promoting steam flow through the annulus, thereby extending the rotor's lifespan and preventing potential failure.
Implementation Method 1
urging a steam flow through the annulus for reducing a temperature of the turbine rotor
Implementation Method 2
A difference between the first reaction and second reaction is capable of urging a steam flow through the annulus
Data Source
AI summary
A steam turbine includes a turbine rotor, a generator end having a generator end first stage with a first reaction, and a turbine end having a turbine end first stage with a second reaction not equal to the first reaction. The steam turbine includes a tub section disposed between the generator end and the turbine end, the turbine rotor and the tub section defining an annulus therebetween. A difference between the first reaction and second reaction is capable of urging a steam flow through the annulus for reducing a temperature of the turbine rotor. A method of cooling the turbine rotor is also disclosed.