Thermomagnetic Generator Using Segmented Materials for Broad Temperature Conversion

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Solution Overview

Problem

Current thermomagnetic generators struggle to efficiently convert thermal energy into electrical energy at temperatures close to room temperature without intermediate mechanical work, limiting their application in utilizing waste heat from industrial processes and solar energy.

Innovation Solution

A thermoelectric generator utilizing a series of at least three different metal-based thermomagnetic materials with varying magnetocaloric effects, selected from specific compounds and Heusler alloys, is designed to operate within the -20 °C to 200 °C range, exploiting an increased temperature range for energy conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If traditional thermomagnetic generators use single-material designs, then the device complexity is low, but the temperature range for efficient energy conversion is limited

Engineering Contradiction:
Improvetemperature rangeVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The generator is divided into multiple chambers, each containing a different thermomagnetic material optimized for specific temperature ranges. This segmentation allows each material to operate at its optimal temperature while collectively covering a broad temperature spectrum from cryogenic to high-temperature applications.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite material structures where multiple thermomagnetic materials with different Curie temperatures are combined within a single device architecture. This composite approach enables the system to harvest thermal energy across diverse temperature conditions by leveraging the complementary properties of each material.

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If rapid quenching is applied to reduce thermal hysteresis, then the energy conversion efficiency improves, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvethermal hysteresisVSAvoidmanufacturing precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent utilizes rapid quenching to dramatically change the cooling rate parameter during material fabrication. This parameter change suppresses thermal hysteresis by creating a non-equilibrium microstructure that reduces the temperature difference between heating and cooling cycles, thereby improving energy conversion efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The manufacturing process incorporates periodic heating and rapid quenching cycles to repeatedly refine the material microstructure. This periodic thermal treatment progressively reduces thermal hysteresis while establishing a stable, low-hysteresis microstructure in the final product.

Inventive Principle:
Principle #19Periodic action

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 enables efficient conversion of waste heat and solar energy into electrical energy across a broad temperature range, particularly effective between 20 °C to 150 °C, with high energy yields and reduced thermal hysteresis through rapid quenching and optimized material composition.

Implementation Method 1

The materials used in thermomagnetic generators are based on the magnetocaloric effect (MCE). In a material that exhibits a magnetocaloric effect, the alignment of randomly oriented magnetic moments by an external magnetic field results in heating of the material.

Methodology Applied
Scientific EffectMagnetocaloric effect: Magnetocaloric Effect

Implementation Method 2

When an electrical conductor is exposed to a varying magnetic field, the changes in the magnetic field result in the induction of an electric current in the conductor.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2272111B1Thermomagnetic generator
Publication Date: 2015.01.28 TECH FOUND STW

AI summary

The invention relates to a thermomagnetic generator which converts thermal energy to electrical energy without intermediate conversion to mechanical work and which works at temperatures in the range of -20°C to 200°C. Said thermomagnetic generator comprises a thermomagnetic material which is e.g. selected from (1) compounds of general formula (I): (AyBy-1)2+dCwDxEz (I), wherein A represents Mn or Co; B represents Fe, Cr or Ni; C, D, E represent elements C, D, E at least two of which are different, have a not insignificant concentration and are selected from P, B, Se, Ge, Ga, Si, Sn, N, As and Sb, at least one of C, D and E representing Ge or Si; d is a number in the range of -0.1 to 0.1; w, x, y, z are numbers in the range of 0 to 1, w + x + z = 1.