Dual-Circuit Redox Cycle Device Heat Recovery

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Solution Overview

Problem

Conventional redox cycle processes face challenges in efficiently recovering sensitive heat from redox materials due to high temperature gradients and the need for high-temperature gas separation, which complicates the recovery of thermal energy and increases energy losses.

Innovation Solution

A dual-circuit system is implemented, where a first circuit for the redox material and a second circuit for the purge gas are largely separated, with the purge gas functioning as a heat transfer medium to preheat and reduce the redox material, allowing for effective heat recovery and reduced oxygen partial pressure without mechanical shut-off devices, thus optimizing thermal energy usage and reducing re-oxidation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the purge gas flows through the main radiation receiver to reduce oxygen partial pressure, then the reduction efficiency is improved, but the thermal energy recovery becomes difficult and energy losses increase

Engineering Contradiction:
Improvereduction efficiencyVSAvoidthermal energy loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The system is divided into two separate circuits: a first circuit for the redox material flowing through the main radiation receiver, and a second circuit for the purge gas that bypasses the radiation receiver. This segmentation allows the purge gas to be heated indirectly through heat exchangers, enabling thermal energy recovery while maintaining effective oxygen partial pressure reduction in the redox material circuit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Heat exchangers serve as intermediary devices that transfer thermal energy from the heated redox material to the purge gas without direct mixing of the two flows. This intermediary mechanism enables efficient heat recovery while keeping the circuits separate, resolving the contradiction between reduction efficiency and energy loss.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If high temperature gradients are present in the redox material, then the reduction process is effective, but the sensible heat recovery becomes difficult and requires complex high-temperature gas separation

Engineering Contradiction:
Improvereduction effectivenessVSAvoidgas separation device complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The purge gas circuit is extracted and separated from the main radiation receiver, allowing thermal energy to be recovered through heat exchangers at lower temperatures. This extraction eliminates the need for complex high-temperature gas separation devices while maintaining effective reduction through controlled oxygen partial pressure.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If quartz glass windows are used in the main radiation receiver for cooling, then the structural integrity is maintained, but the device complexity and energy losses increase

Engineering Contradiction:
Improvestructural integrityVSAvoidcooling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The purge gas circuit is extracted to bypass the main radiation receiver, eliminating the need for quartz glass windows and their associated cooling systems. The purge gas is heated indirectly through heat exchangers, maintaining structural integrity without the complexity of high-temperature window cooling.

Inventive Principle:
Principle #2Taking out (Extraction)

4Strength

If the redox material is kept in a block structure, then the mechanical strength is maintained, but the sensible heat recovery efficiency decreases due to high temperature gradients

Engineering Contradiction:
Improvemechanical strengthVSAvoidsensible heat loss
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The system segments the heat transfer process into two separate circuits with distinct functions. The redox material can maintain its block structure for mechanical strength in the radiation receiver, while the separate purge gas circuit recovers thermal energy efficiently through heat exchangers, minimizing sensible heat loss.

Inventive Principle:
Principle #1Segmentation

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 approach enhances the efficiency of the redox cycle process by up to 27%, significantly improving upon the state of the art by effectively utilizing thermal energy and minimizing energy losses, while eliminating the need for quartz windows and mechanical pressure separation.

Implementation Method 1

a first circuit (1) for a first heat transfer medium (4) and a second circuit (2) for a purge gas (6) as a second heat transfer medium... The second heat transfer medium flows through the first heat transfer medium

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

heating an oxide material to carry out a reduction process... concentrated solar power must be varied cyclically

Methodology Applied
Scientific EffectSolar radiation absorption: Absorption (EM radiation)

Implementation Method 3

Redox cycles, driven by concentrated solar radiation, allow for the low-emission production of hydrogen

Methodology Applied
Scientific EffectConcentrated solar heating: Solar Energy

Implementation Method 4

supplying water vapor and/or carbon dioxide to the reduced oxide material, wherein the reduced oxide material is oxidized to oxide material and hydrogen and/or carbon monoxide is released

Methodology Applied
Scientific EffectOxidation reaction: Oxidation

Implementation Method 5

a metal oxide, the so-called redox material, is typically reduced at high temperatures and then oxidized again at lower temperatures

Methodology Applied
Scientific EffectRedox reaction: Redox Reactions

Data Source

PatentEP4421025A1Device and method for carrying out a redox cycle process
Publication Date: 2024.08.28 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V
  • EP4421025A1 patent drawingFigure 1
  • EP4421025A1 patent drawingFigure 2
  • EP4421025A1 patent drawing

AI summary

The invention relates to a device (100) and a method for carrying out a redox cycle with a first circuit (1) for a first heat transfer medium (4) and a second circuit (2) for a purge gas (6) as the second heat transfer medium. The first circuit (1) runs in the flow direction of the first heat transfer medium (4) through at least one first heat exchanger (20), a main radiation receiver (10), a second heat exchanger (30), and an oxidation reactor (40). The second circuit (2) runs between the first and second heat exchangers (20, 30) in a line that passes by the main radiation receiver (10) and leads in the flow direction of the second heat transfer medium from the second heat exchanger (30) to the first heat exchanger (20).The second circuit (2) is coupled to the first circuit (1) at the first heat exchanger (20) and/or at the second heat exchanger (30), wherein the first heat transfer medium (4) is circulated through by the second heat transfer medium.