PTC Heating Element End-Face Contacts for High Heat Density

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Solution Overview

Problem

Existing electrical heating devices for motor vehicles are space-consuming, complex, and inefficient in heat dissipation, particularly for PTC elements used in electromobility, where high heat density and efficient thermal extraction are required.

Innovation Solution

An electrical heating device design featuring a housing with inlet and outlet openings for fluid circulation, where PTC elements are thermally coupled to a circulation chamber and electrically conductively contacted on end faces with metal strips, allowing direct exposure of heat-emitting surfaces for improved heat dissipation without contact plates, enabling a compact and efficient arrangement of multiple PTC elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If contact plates are used on both main side faces of the PTC element, then electrical contact is achieved, but the device becomes bulky and heat dissipation is impaired

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidstructural complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent removes the contact plates from the main side faces of the PTC element, extracting the unnecessary component that was impeding heat dissipation. Electrical contact is instead achieved through the end faces of the PTC element, allowing the main side faces to be fully exposed for thermal exchange with the circulating fluid.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the dimension of electrical contact from the main side faces (where contact plates were located) to the end faces of the PTC element. This dimensional shift allows the main side faces to be dedicated entirely to heat dissipation while electrical contact is maintained through the end faces.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Power

If PTC elements are arranged closely together, then heat density increases, but manufacturing and assembly become more difficult

Engineering Contradiction:

Improveheat densityVSAvoidassembly ease

Core Design Contradiction:

PowerVSEase of manufacture

Solution Approach 1:

The patent segments the PTC heating element into modular units with standardized end-face contact interfaces. Each PTC element can be independently manufactured and then assembled in close proximity within the housing, with the end-face contact structure enabling simple connection without requiring complex alignment or additional components.

Inventive Principle:

Principle #1Segmentation

3Length of moving object

If contact plates are used for electrical contact, then electrical connection is reliable, but the device thickness increases

Engineering Contradiction:

Improvedevice thicknessVSAvoidelectrical contact reliability

Core Design Contradiction:

Length of moving objectVSReliability

Solution Approach 1:

Instead of contacting the PTC element through its large main side faces as in conventional designs, the patent inverts the contact approach by making electrical contact through the small end faces of the PTC element. This inversion dramatically reduces the device thickness while maintaining reliable electrical connection through the end-face contact structure.

Inventive Principle:

Principle #13The other way round (Inversion)

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 design achieves high heat density and efficient heat dissipation by exposing a large surface area of PTC elements directly to the fluid, reducing the device's thickness and enhancing thermal extraction, thus improving the operational efficiency of PTC heating elements in motor vehicles.

Implementation Method 1

PTC heating element with heat-emitting surfaces that are thermally coupled to a PTC element

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the heat-emitting surfaces of a PTC heating element are exposed. These surfaces are thermally coupled to a PTC element

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

The fluid is passed through a circulation chamber in which the heat-emitting surfaces of a PTC heating element are exposed

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentEP3334245B1Electric heating device and PTC heating element of an electric heating device

Publication Date: 2019.10.30 EBERSPACHER CATEM GMBH & CO KG

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AI summary

The present invention relates to an electrical heating device with a housing (2) which forms inlet and outlet openings (10, 12) for the fluid to be heated and a circulation chamber (14) in which a heat-emitting surface of a PTC heating element (40) is exposed which is thermally conductively coupled to a PTC element (120) which is electrically conductively contacted with electrical conductor tracks (128) to different polarities, and a PTC element of such an electrical heating device. According to the invention, a high heat density and a high degree of efficiency are achieved in that the conductor tracks (128) are electrically conductively contacted on the end faces (126) of the PTC element (120).