Phase Change Material Heat Exchanger for Thermoelectric Generator Thermal Buffering

Solution Overview

Problem

Thermoelectric generators used in automotive exhaust lines face high temperatures, leading to thermal stresses and the need for expensive high-temperature-resistant materials, as well as complex bypass systems to manage temperature fluctuations.

Innovation Solution

A heat exchange device with a phase change material positioned in a bypass duct upstream of the thermoelectric module, which absorbs and releases heat during phase changes to stabilize exhaust gas temperatures, reducing thermal stresses and optimizing electric current generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If thermoelectric generators are positioned in the exhaust line to generate electrical energy from exhaust heat, then electrical energy generation is improved, but thermal stresses on the generator increase due to high temperature peaks

Engineering Contradiction:

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

A heat exchange device with phase change material is introduced as an intermediary between the exhaust line and thermoelectric generator. The phase change material absorbs excess heat during phase transition, acting as a thermal buffer that protects the thermoelectric generator from temperature peaks while maintaining effective heat utilization for electricity generation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention utilizes phase change material that undergoes phase transition (solid-liquid or liquid-gas) at a specific temperature range. During phase change, the material absorbs or releases latent heat, effectively stabilizing the temperature reaching the thermoelectric generator and reducing thermal stresses without compromising energy generation efficiency.

Inventive Principle:

Principle #36Phase transitions

2Reliability

If bypass ducts are provided to limit temperature rises in thermoelectric generators, then thermal stress resistance is improved, but device complexity increases

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The heat exchange device with phase change material is integrated into the existing exhaust line structure, merging the temperature control function with the exhaust flow path. This eliminates the need for separate complex bypass ducting systems while achieving the same thermal protection objective.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The phase change material provides automatic temperature regulation without requiring external control systems, valves, or complex bypass mechanisms. The material self-regulates temperature through its inherent phase change properties, simplifying the overall system design and reducing complexity.

Inventive Principle:

Principle #25Self-service

3Reliability

If materials resistant to high temperatures are used in thermoelectric generators, then thermal stress resistance is improved, but manufacturing cost increases

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The phase change material serves as a thermal intermediary that protects the thermoelectric generator from direct exposure to high-temperature exhaust gases. This allows the use of less expensive, lower-temperature-resistant materials in the generator construction while maintaining reliability through the protective thermal buffering effect.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 device effectively smooths temperature peaks and fluctuations, allowing for the use of less expensive materials and enhancing the efficiency of thermoelectric energy generation by stabilizing the temperature of exhaust gases before they reach the thermoelectric generator.

Implementation Method 1

a phase change material, said body being configured so that the phase-change material changes phase as a function of the temperature of said gases

Methodology Applied

Scientific EffectPhase change: Phase Change

Implementation Method 2

said material is capable of storing and/or releasing heat during its phase changes

Methodology Applied

Scientific EffectLatent heat: Latent Heat

Implementation Method 3

making it possible to generate an electric current in the presence of a temperature gradient between two of their opposite faces according to the phenomenon known as the effect Seebeck

Methodology Applied

Scientific EffectSeebeck effect: Seebeck Effect

Data Source

PatentEP2952706B1Heat-exchange device, exhaust line of a combustion engine and thermoelectric module including such a device

Publication Date: 2017.03.15

AI summary

The invention relates to a heat exchange device (30) characterized in that it comprises a body for positioning along a gas exhaust line (10) and a phase-change material (32), said body being configured so that the phase-change material (32) changes phase depending on the temperature of said gas. The invention also relates to an exhaust line (10) of a heat engine (40) comprising such a device (30) and a thermoelectric module (20) comprising such a device (30).