Permeable Gas Conduit Reactor for Uniform High-Temperature Heating

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Solution Overview

Problem

Current gas heating reactors face challenges in efficiently heating gases at high temperatures and pressures using exothermic gas-solid reactions, particularly in Brayton cycles and chemical looping combustion processes, due to issues like hot spots, solid entrainment, and inefficient heat transfer, which limits energy conversion efficiency and increases costs.

Innovation Solution

A reactor design featuring gas conduits with permeable walls and orifices that separate solids from gases, allowing controlled diffusion of reactive gases to slow down reaction rates and distribute heat evenly, using materials like carbonaceous fuels, metals, or calcium oxide, and additional high thermal conductivity materials to enhance heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If solid fuels are burned at high pressure to heat compressed gas flow, then energy conversion efficiency is improved, but hot spots and temperature profiles cause ash softening, melting, and fouling

Engineering Contradiction:
Improveenergy conversion efficiencyVSAvoidtemperature profile uniformity
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The reactor divides the gas flow into multiple parallel streams through numerous conduits distributed throughout the solid fuel bed. Each conduit independently heats the gas portion passing through it, segmenting the overall heating process into many small, distributed units rather than one large集中 heating zone, thereby preventing hot spots

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reactor introduces an intermediary structure (the conduit system with permeable walls) between the solid fuel and the gas flow. This intermediary enables controlled heat and mass transfer while preventing direct contact between solids and gas, moderating the intensity of the exothermic reaction and distributing heat more uniformly

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If solid fuels are directly contacted with compressed gas flow, then heat transfer efficiency is improved, but solid particles entrain in the flue gas stream requiring costly cleanup equipment

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidsolid particle entrainment
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The conduit walls act as an intermediary barrier that allows heat and mass transfer between the solid fuel and gas flow while physically preventing solid particle entrainment. The permeable walls with orifices enable controlled interaction without direct contact

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The conduit walls are made of porous materials with controlled porosity (0.1 to 0.5) and orifices (1 to 3 mm length) that allow selective passage of gas molecules while blocking solid particles. This porous structure enables heat and mass transfer while maintaining particle separation

Inventive Principle:
Principle #31Porous materials

3Object-affected harmful factors

If externally fired heaters are used to avoid direct contact between combustion gases and turbine blades, then solid fuel applications become feasible, but relatively large heat transfer area and thicker heat transfer walls are required

Engineering Contradiction:
Improvesolid particle protectionVSAvoidreactor volume
Core Design Contradiction:
Object-affected harmful factorsVSVolume of stationary object

Solution Approach 1:

The reactor transitions from conventional external firing where heat transfers through thick walls to a configuration where gas flows through conduits embedded within the fuel bed. This dimensional reorganization allows heat transfer to occur through the conduit walls from all directions, dramatically increasing the effective heat transfer area per unit volume

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The reactor nests the gas conduits within the solid fuel bed, creating a hierarchical structure where conduits are embedded in the porous matrix of burning solids. This nested arrangement allows the working fluid to be surrounded by the heat source from multiple directions, intensifying heat transfer

Inventive Principle:
Principle #7Nested doll (Nesting)

4Power

If gas-solid reactions proceed at high rates to generate sufficient heat, then power output is improved, but strong temperature profiles and hot spots are generated causing ash softening or melting

Engineering Contradiction:
Improvepower outputVSAvoidash stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The reactor segments the high-rate gas-solid reactions into many parallel reactions occurring simultaneously in numerous conduits throughout the fuel bed. This distribution of reaction zones prevents the concentration of thermal energy in single locations, maintaining high overall power output while avoiding localized hot spots that would compromise ash stability

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 design prevents solid contamination, reduces hot spots, and achieves stable, efficient heat transfer, enabling high-energy conversion efficiencies while minimizing reactor volume and pressure drops, making it suitable for intermittent power generation and energy storage applications.

Implementation Method 1

the active gas component, forced to diffuse from the gas conducts through the orifices of the gas conduct wall

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

the heat source to heat up the gas is generated by the exothermic reaction of the solids with one active component of the gas

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Implementation Method 3

the heat generated by the reaction of the gas with the solids to be more evenly distributed through the reactor

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3801866B1Use of a reactor for heating a gas
Publication Date: 2022.10.26 CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS (CSIC)
  • EP3801866B1 patent drawingFigure 1
  • EP3801866B1 patent drawingFigure 2
  • EP3801866B1 patent drawingFigure 3

AI summary

This invention discloses a reactor and methods for heating of a gas as it reacts with a solid. The reactor contains gas conducts that are empty of solids and that cross through a region packed with solids. The wall of the gas conducts has orifices to make it permeable but not selective to gases, while effectively separating the solids from the gas. In the reactor, the heat source to heat up the gas is generated by the exothermic reaction of the solids with one active component of the gas. The region packed with the reacting solids is at temperatures ranging from 500°C to 1500°C, to promote the heat transfer towards the gas and the high reactivity of the solids with the active components of the gas, that is forced to diffuse from the conduct through the orifices of the conduct wall.