Measuring Element for Urea Liquid Identification via Boiling Point

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Solution Overview

Problem

Existing methods for detecting the concentration and quality of aqueous urea solutions in DENOX systems are inadequate, as they rely on pH and electrical conductivity, which are insufficient for accurate identification, leading to potential system failure or damage due to incorrect filling or aging processes.

Innovation Solution

A measuring element that provokes a phase transition of the liquid, such as boiling or freezing, and correlates the resulting material properties to determine the liquid's properties accurately, allowing for the detection of urea concentration and other parameters, and is integrated into the reservoir's filler neck to prevent incorrect filling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If pH and electrical conductivity are used to detect liquid concentration, then the detection method is simple, but the measurement precision is insufficient for accurate liquid identification

Engineering Contradiction:
Improvedetection method simplicityVSAvoidliquid identification accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent changes the detection parameter from pH and electrical conductivity to boiling point temperature. By heating the liquid to its boiling point and measuring the temperature, the system achieves accurate identification of the liquid type (water, urea solution, fuel, etc.) since each liquid has a distinct boiling point, resolving the contradiction between simple detection and accurate measurement.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes the phase transition from liquid to gas (boiling) as the detection mechanism. By observing the temperature at which the liquid transitions to vapor phase, the system can precisely identify the liquid type. This phase transition approach provides both operational simplicity and high measurement precision, effectively resolving the technical contradiction.

Inventive Principle:
Principle #36Phase transitions

2Measurement precision

If the liquid in the reservoir is heated to boiling temperature for analysis, then accurate material property determination is achieved, but energy consumption increases

Engineering Contradiction:
Improvematerial property determination accuracyVSAvoidenergy consumption for heating
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the liquid sampling process by extracting only a small amount of liquid from the reservoir for analysis rather than heating the entire reservoir contents. This is achieved by introducing the liquid to be analyzed into a separate analysis chamber or using a probe that contacts a small sample, thereby reducing energy consumption while maintaining accurate boiling point measurement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by heating only a small portion of the liquid (a sample) to boiling temperature rather than heating the entire volume in the reservoir. This partial heating approach achieves sufficient measurement precision for liquid identification while significantly reducing the energy required compared to heating the complete liquid volume.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If a measuring element is integrated into the filler neck, then prevention of incorrect filling is achieved, but device complexity increases

Engineering Contradiction:
Improveprevention of system damageVSAvoidmeasuring element integration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements preliminary action by incorporating the measuring element directly into the filler neck, enabling detection of the liquid type immediately upon filling. This allows the system to verify the correctness of the filled liquid before it enters the reservoir, preventing incorrect filling and potential system damage. The integrated design performs the measurement function in advance, simplifying the overall system architecture.

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 method provides a reliable and accurate means to identify the correct liquid in the reservoir, preventing system damage by determining the material properties through phase transitions, ensuring the correct filling and operation of DENOX systems.

Implementation Method 1

the liquid or the derivative of the liquid is heated up to a boiling temperature of the liquid or a boiling or decomposition temperature of the derivative

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the measuring element determines both a pressure and a temperature of the liquid or a derivative of the liquid

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 3

the measuring element determines both a pressure and a temperature of the liquid or a derivative of the liquid

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 4

Aqueous urea solution is subject to an aging process, during which part of the urea breaks down into ammonia and carbon dioxide

Methodology Applied
Scientific EffectDecomposition: Decomposition (biological)

Data Source

PatentEP2893164B1Measurement element and method for differentiating various kinds of liquids
Publication Date: 2019.09.11 ROBERT BOSCH GMBH
  • EP2893164B1 patent drawingFigure 1~2
  • EP2893164B1 patent drawingFigure 3~4

AI summary

The invention relates to a measurement element (50) and a method for differentiating various kinds of liquids (12), in particular for measuring a concentration of an aqueous urea solution, wherein a phase transition of a liquid (12) or a derivative of the liquid (12) is caused and the liquid (12) or the derivative of the liquid (12) is recognised on the basis of substance properties that correlate to the phase transition of the liquid (12) or of the derivative of the liquid (12).