Exhaust Sensor Cleaning via Fluid Blast

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Solution Overview

Problem

Soot deposition on exhaust gas sensors, such as lambda sensors, leads to inaccurate measurements, affecting air/fuel ratios and increasing fuel consumption and emissions, as existing cleaning methods are not effectively adapted for internal combustion engines.

Innovation Solution

An arrangement and method involving a fluid outlet in the exhaust gas system to direct a high-pressure, short-duration fluid blast onto the sensor, using an air/liquid mixture to mechanically remove soot and oxidize it, ensuring effective cleaning of the sensor surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sensor is heated to high temperature to remove soot deposits, then the sensor surface is cleaned, but this solution is not adapted for internal combustion engines and requires additional energy consumption

Engineering Contradiction:
Improvesensor cleaning effectivenessVSAvoidenergy consumption for heating
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent uses a fluid outlet to direct a blast of fluid (air or liquid) onto the sensor surface to mechanically remove soot deposits. This pneumatic/hydraulic approach replaces thermal heating with fluid dynamics, eliminating the need for additional energy-consuming heating elements while effectively cleaning the sensor in internal combustion engine environments.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The invention replaces the thermal field (heating system) with a mechanical field (fluid blast system). By using high-velocity fluid flow to physically remove soot particles from the sensor surface, the system substitutes a mechanical cleaning mechanism for the previously proposed thermal cleaning method, making it suitable for internal combustion engines where high energy consumption is undesirable.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a fluid outlet is used to direct a blast of fluid on the sensor, then soot is removed effectively, but the device complexity increases

Engineering Contradiction:
Improvesensor cleaning effectivenessVSAvoidexhaust gas system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fluid outlet is integrated into the existing exhaust gas system, allowing the exhaust system to serve dual functions: exhaust gas flow and sensor cleaning. By utilizing the existing fluid pathways and pressure in the exhaust system, the invention avoids adding completely separate cleaning hardware, thereby reducing overall device complexity while maintaining cleaning effectiveness.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The exhaust gas system itself provides the cleaning function through its inherent fluid flow. The high-velocity exhaust gases or dedicated fluid supply already present in the system are directed onto the sensor surface, allowing the system to clean itself without requiring external cleaning equipment. This self-service approach minimizes additional device complexity.

Inventive Principle:
Principle #25Self-service

3Reliability

If the vehicle is driven at high speeds for longer time intervals, then soot deposition is reduced, but this is not always possible depending on driving conditions

Engineering Contradiction:
Improvesensor cleanlinessVSAvoidadaptability to different driving conditions
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

Instead of relying on continuous high-speed driving to prevent soot deposition, the invention implements periodic cleaning action through the fluid outlet. The system can periodically direct fluid blasts onto the sensor surface regardless of current driving conditions, ensuring consistent sensor cleanliness whether the vehicle is driven at high speed, low speed, or idle. This periodic active cleaning compensates for varying driving conditions.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The fluid outlet system can be activated to clean the sensor before soot accumulation becomes problematic, or at optimal moments during operation. By performing cleaning actions proactively rather than reactively, the system maintains sensor reliability across all driving conditions without requiring specific high-speed driving patterns.

Inventive Principle:
Principle #10Preliminary 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

This approach allows for accurate sensor readings by removing soot deposits, maintaining optimal air/fuel ratios, reducing emissions, and preventing catalytic converter damage, while being cost-effective and adaptable to various driving conditions.

Implementation Method 1

the fluid outlet is adapted to direct a blast of fluid on the exhaust gas sensor

Methodology Applied
Scientific EffectImpact force: Impact Force

Implementation Method 2

using an air/liquid mixture to mechanically remove soot and oxidize it

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3546715B1Device and method for cleaning a sensor in an exhaust system and a vehicle comprising such a device
Publication Date: 2022.02.23 VOLVO CAR CORP
  • EP3546715B1 patent drawingFigure 1~2
  • EP3546715B1 patent drawingFigure 3
  • EP3546715B1 patent drawingFigure 4

AI summary

An arrangement adapted for removing soot from an exhaust gas sensor in an exhaust gas system of a vehicle comprising a combustion engine, where the arrangement comprises a fluid outlet arranged in an exhaust gas conduit, and where the fluid outlet is adapted to impinge a blast of fluid on the exhaust gas sensor. The advantage of the invention is that an exhaust gas sensor can easily be cleaned in order to ensure a correct reading from the sensor.