Electric Machine Sealing with Leak Detection Conduits
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Solution Overview
Problem
Electric machines cooled with inflammable fluids, such as hydrogen, face safety risks due to potential leaks near the connection circuit, leading to non-scheduled stops when leaks occur, as existing sealing methods are inadequate for real-time detection and maintenance.
Innovation Solution
The implementation of three sealing assemblies in series along the exit path of the cooling fluid, with conduits to detect leaks and determine which assembly has failed, allowing for continued safe operation and reduced downtime by identifying and isolating the source of leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two gaskets are arranged in series between the shaft and the connection circuit, then sealing tightness is improved, but the complexity of detecting and measuring leakage increases
Solution Approach 1:
The patent divides the sealing system into three separate sealing assemblies arranged in series along the exit path of the cooling fluid. Each sealing assembly can be independently tested through dedicated detection conduits, allowing localized identification of leakage sources without requiring system-wide shutdown or complex diagnostic procedures.
Solution Approach 2:
The patent introduces detection conduits as intermediary elements that connect to specific zones between sealing assemblies. These conduits enable direct sampling and analysis of cooling fluid leakage at defined locations, simplifying the detection process by providing accessible measurement points without requiring disassembly of the connection circuit.
2Reliability
If a leak occurs while the electric generator is running, then the machine must be stopped for replacement of damaged components, but this causes long non-scheduled stops and energy production loss
Solution Approach 1:
The patent implements preliminary detection capabilities through detection conduits that continuously monitor for cooling fluid leakage before it becomes a critical safety issue. By detecting leaks early and identifying their specific location, the system allows for planned maintenance scheduling rather than emergency shutdowns, enabling proactive replacement of sealing components during scheduled outages.
Solution Approach 2:
The segmented sealing assembly design with independent detection conduits enables localized fault identification. When a leak is detected, the system can pinpoint which specific sealing assembly has failed, allowing maintenance teams to replace only the affected component rather than the entire connection circuit, thereby reducing maintenance time and complexity.
3Difficulty of detecting and measuring
If three sealing assemblies are arranged in series with detection conduits, then the ability to detect and locate leaks is improved, but the device complexity increases
Solution Approach 1:
The patent segments both the sealing function and detection function into modular units. Three sealing assemblies are distributed along the cooling fluid exit path, each with its own detection conduit connection point. This segmentation transforms a complex monolithic sealing system into manageable modular units that can be independently installed, tested, and maintained.
Solution Approach 2:
The detection conduits serve multiple functions: they provide leakage detection, locate the source of leaks, and enable pressure testing of individual sealing assemblies. This multi-functionality reduces the need for separate diagnostic equipment and procedures, offsetting the increased complexity of having three sealing assemblies with dedicated detection access.
Data Source
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AI summary
An electric machine cooled with an inflammable cooling fluid has a rotor (2) rotatable about an axis (A1) and stator casing (3) arranged, in part, about the rotor (2) and suitable to define a space (9) occupied by the cooling fluid; the rotor (2) has a shaft (4); at least one excitation electric winding (5) arranged in the space (9); a connecting circuit (6) extending, at least in part, into the shaft (4) in an electrically insulated manner from the shaft (4) and suitable to connect the excitation electric winding (5) with the outside of the stator casing (3); a plurality of holes (14, 15, 16, 17, 18) suitable to define a housing for the connecting circuit (6) and at least a possible exit path for the inflammable cooling fluid; and a first, a second, and a third sealing assembly (26, 27, 28) arranged in series along said path between the connecting circuit (6) and the shaft (4) and a first and a second conduits (22, 41) suitable to connect with the outside respectively a path zone between the second and the third sealing assemblies (27, 28) and a path zone between the first and the second sealing assemblies (26, 27).