Honeycomb Structure with Induction Heating for Exhaust Purification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing exhaust gas purifying devices face challenges in efficiently removing carbon fine particles while minimizing pressure loss, especially when condensed water is present, and previous heating methods can lead to electric short circuits or inefficient energy use.

Innovation Solution

A honeycomb structure with alternating cells, where one set is open on the inflow side and the other on the outflow side, both containing magnetic substances, and a coil wiring spirally surrounding the outer circumference for induction heating, allowing localized heating and reducing pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If induction heating by inserting a metal wire into non-conductive honeycomb cells is used to burn out carbon fine particles, then carbon fine particles can be removed even when condensed water is generated, but some cells cannot be used as gas flow paths and filtration area is decreased

Engineering Contradiction:

Improvecarbon fine particle removal capabilityVSAvoidfiltration area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The honeycomb structure is divided into two types of cells: cells with magnetic substance plugs for induction heating and cells without magnetic substance plugs for gas flow. This segmentation allows the heating function to be localized to specific cells while maintaining other cells as functional flow paths, thus preserving filtration area while enabling carbon fine particle removal.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Magnetic substances are locally inserted into specific cells (alternating cells) rather than all cells. This local quality approach enables induction heating to occur in designated cells while other cells maintain their original filtration function, resolving the contradiction between heating capability and filtration area.

Inventive Principle:

Principle #3Local quality

2Temperature

If electric current is passed through conductive honeycomb structure to heat it by Joule heat, then carbon fine particles can be burned out, but electric short circuit occurs if condensed water is generated

Engineering Contradiction:

Improvehoneycomb structure temperatureVSAvoidelectric short circuit prevention

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

A magnetic substance acts as an intermediary between the external coil and the honeycomb structure. The magnetic substance converts electromagnetic energy from the coil into heat through hysteresis loss, eliminating the need to pass electric current through the honeycomb structure itself. This intermediary approach enables heating while preventing electric short circuits caused by condensed water.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If filter is placed at underfloor position to ensure mounting space, then design freedom is improved, but exhaust gas temperature is decreased and carbon fine particles accumulate

Engineering Contradiction:

Improvemounting flexibilityVSAvoidexhaust gas temperature

Core Design Contradiction:

Ease of operationVSTemperature

Solution Approach 1:

The natural thermal convection system is replaced with an active induction heating system. Instead of relying on exhaust gas temperature to burn out carbon fine particles, an external coil provides electromagnetic induction heating to directly heat the honeycomb structure. This substitution allows the filter to be installed at the underfloor position while maintaining the temperature needed for carbon fine particle combustion.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 configuration effectively burns out and removes carbon fine particles with reduced pressure loss and energy input, improving energy efficiency and preventing electric short circuits.

Implementation Method 1

a coil wiring that spirally surrounds an outer circumference of the honeycomb structure

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

one or both of the plugged portions of the cells A and the plugged portions of the cells B include a magnetic substance

Methodology Applied

Scientific EffectEddy currents: Eddy Currents

Implementation Method 3

burns out and remove carbon fine particles by electric heating

Methodology Applied

Scientific EffectInduction heating: Induction Heating

Data Source

PatentUS11369952B2Honeycomb structure and exhaust gas purifying device

Publication Date: 2022.06.28 NGK INSULATORS LTD

AI summary

A pillar shaped honeycomb structure includes: a porous partition wall that defines a plurality of cells, the cells forming flow paths for a fluid, the cells extending from an inflow end face to an outflow end face; and an outer peripheral wall located at the outermost circumference. The cells include: a plurality of cells A wherein a side of the inflow end face is opened and the outflow end face has a plugged portion; and a plurality of cells B wherein a side of the outflow end face is opened and the inflow end face has a plugged portion, the cells B being arranged alternately with the cells A. One or both of the plugged portion of the cells A and the plugged portions of the cells B contain a magnetic substance and glass.