Heat Transfer Element Dielectric Coating Thermal Expansion
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Solution Overview
Problem
Conventional electric machines face challenges in efficiently dissipating heat from stator windings, leading to potential crack propagation in dielectric coatings and reduced reliability due to mismatched thermal expansion rates between materials.
Innovation Solution
A heat transfer element with a thermally conductive body and dielectric coating is applied in an expanded state, allowing the coating to compress and then expand with the body, reducing the likelihood of cracking and enhancing thermal conductivity for improved heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dielectric coating is applied on a heat transfer element body, then electrical insulation is improved, but crack propagation occurs due to mismatched thermal expansion rates
Solution Approach 1:
The patent applies the dielectric coating to the heat transfer element body when the body is in an expanded state (at elevated temperature). This parameter change in the body's dimensional state during coating application ensures that the coating is applied at the correct dimensional reference point, accounting for thermal expansion. As a result, when the body contracts to its normal operating temperature, the coating remains in a compressed state rather than being put under tensile stress, preventing crack propagation and maintaining both electrical insulation and coating integrity.
2Temperature
If the heat transfer element body expands due to heat application, then heat dissipation capability is improved, but the dielectric coating may crack due to expansion stress
Solution Approach 1:
The patent performs the coating application action in advance, specifically when the heat transfer element body is in its expanded state at elevated temperature. This preliminary action of coating at the expanded state ensures that the coating is applied when the body dimensions are at their maximum. Consequently, when the body subsequently contracts during normal operation, the coating is placed in compression rather than tension, eliminating the risk of crack propagation during thermal cycling while maintaining reliable heat dissipation capability.
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 provides superior thermal and electrical operation, enabling higher power generation and reduced maintenance needs by minimizing crack formation and electrical shorts, thus extending the operating life and reducing costs.
Implementation Method 1
The subsequent expansion of the body in response to an application of heat results in the expansion of the dielectric coating to move it from a compressed state to an uncompressed state
Implementation Method 2
a body defining a face for contacting the end turns to transfer heat via conduction from the windings
Data Source
AI summary
An electric machine, such as a generator, providing for the generation of electricity and includes a rotor generating a magnetic field and a stator having stator windings. The interaction of the magnetic field with the stator windings generates current in the windings. The generator may provide the generated current to a power output of the generator, where it may be further transmitted to an electrical load to power the load.