Rotor Winding Head Blocking Element for Low-Flow Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Turbo generators with radial cooling fluid bores in rotor caps face inefficiencies in convective cooling due to excessive volume flow, which reduces cooling effectiveness for both the rotor winding and stator active parts, creating a gas barrier that impedes air gap entry and increases delivery capacity requirements.

Innovation Solution

A blocking element with an inlet opening at a small radius and an outlet opening at a maximum radius, featuring a meandering channel guide to direct cooling fluid along heat-generating components, reduces volume flow and enhances convective cooling by guiding gas flow optimally through gas guide channels made of insulating materials like glass, plastic, or ceramic, positioned between conductors in the rotor winding head.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If radial cooling fluid bores are provided in the rotor cap to improve convective cooling of the rotor winding head, then heat dissipation ability is significantly improved, but the volume flow through the rotor cap increases excessively which reduces cooling effectiveness for the rotor active part and creates a gas barrier at the air gap entry

Engineering Contradiction:
Improveheat dissipation abilityVSAvoidvolume flow
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The rotor cap cooling system is segmented into two distinct functional zones: radial bores for convective cooling of the rotor winding head, and groove base channels for cooling the rotor active part. The blocking element further segments the flow path by introducing flow resistance in the radial direction while preserving groove base channel flow, enabling independent optimization of each cooling zone without mutual interference

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A blocking element is introduced as an intermediary component within the radial bores to regulate and direct the cooling fluid flow. This blocking element with its specific geometry and flow resistance characteristics acts as a mediator that reduces excessive volume flow in the radial direction while maintaining adequate flow for winding head cooling, thereby preventing the gas barrier effect at the air gap entry

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If the size of radial bores is reduced to throttle volume flow and reduce the gas barrier effect, then the cooling conditions for the rotor winding head deteriorate significantly

Engineering Contradiction:
Improvevolume flowVSAvoidcooling conditions
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

Different regions of the cooling system are assigned different flow characteristics: the radial bores are designed with blocking elements to provide localized flow resistance for winding head cooling, while the groove base channels maintain lower resistance for active part cooling. This local differentiation of flow quality allows each region to operate at optimal flow conditions without compromising the other

Inventive Principle:
Principle #3Local quality

3Temperature

If large volume flow is used to cool the rotor winding head effectively, then heat dissipation is improved, but the delivery capacity requirement of the rotor increases which reduces overall efficiency

Engineering Contradiction:
Improveheat dissipation abilityVSAvoiddelivery capacity
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The cooling system is divided into separate flow paths with dedicated blocking elements that segment the volume flow distribution. This segmentation enables the rotor winding head to receive adequate cooling flow without requiring excessive overall volume flow, thereby reducing the delivery capacity requirement and improving overall system efficiency

Inventive Principle:
Principle #1Segmentation

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 configuration significantly improves heat dissipation capacity by up to 2.5 times compared to traditional rotor pumping methods, reducing volume flow by 94% while maintaining effective cooling, thus enhancing the performance and efficiency of turbo generators.

Implementation Method 1

the element preferably has a channel guide which guides the cooling fluid specifically along the heat-generating bodies, for example in a meandering/meandering manner

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

Such an element increases the flow resistance, which results in a reduction in the volume flow

Methodology Applied
Scientific EffectFlow resistance: Drag

Data Source

PatentEP3830933B1Turbogenerator with blocking element for the rotor winding heads and rotor cap with radial ventilation bores.
Publication Date: 2023.09.13 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP3830933B1 patent drawingFigure 1~2

AI summary

The blocking element according to the invention for the rotor head winding of a turbogenerator has a form which is adapted to the contour of the adjacent conductor of the rotor head winding. A depression extending in the axial direction is made in the side of the blocking element facing the conductor, which depression forms a serpentine channel for a cooling fluid from an inlet port on the small radius to a discharge port on the highest radius, with the discharge port communicating with a ventilation bore of the rotor cap enclosing the rotor winding head. The effect of the invention is to provide an improved cooling effect with a reduced flow of cooling fluid and hence to increase the efficiency of the turbogenerator as a whole.