Selective SCR Urea Heating with Segmented Resistive Elements

Solution Overview

Problem

Existing SCR systems for reducing nitrogen oxides in vehicle emissions face inefficiencies in heating urea solutions during cold weather, leading to increased electric consumption and premature degradation of resistive elements, as all heating elements are activated simultaneously, including those not in contact with urea.

Innovation Solution

The use of at least two separate resistive heating elements, where one is activated upon starting the system in freezing conditions for components always in contact with urea, and the other only when actually submerged in urea, with independent activation controlled by temperature sensors and an electronic control unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If all resistive heating elements are activated simultaneously in freezing conditions, then the SCR system components are heated to prevent freezing, but electric consumption increases and resistive elements degrade prematurely

Engineering Contradiction:

Improveprevention of urea freezingVSAvoidelectric consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The heating system is divided into multiple independent resistive heating elements, each associated with specific SCR system components. Instead of activating all heating elements simultaneously, the system segments the heating function and activates only the necessary elements based on real-time detection of urea presence and freezing conditions, thereby reducing overall electric consumption while maintaining reliable freeze protection.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system applies heating locally and selectively to specific components based on their actual need. Temperature sensors and urea detection devices identify which components are in freezing conditions and contain urea, then activate heating elements only at those specific locations, rather than uniformly heating all components throughout the system.

Inventive Principle:

Principle #3Local quality

2Reliability

If all resistive heating elements are activated simultaneously, then components are heated to prevent freezing, but resistive elements undergo premature degradation

Engineering Contradiction:

Improveprevention of urea freezingVSAvoidlifespan of resistive elements

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The heating system is divided into multiple independent resistive heating elements, each associated with specific SCR system components. Instead of activating all heating elements simultaneously, the system segments the heating function and activates only the necessary elements based on real-time detection of urea presence and freezing conditions, thereby reducing overall electric consumption while maintaining reliable freeze protection.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system applies heating only when and where it is actually needed, rather than continuously or excessively heating all components. By using temperature sensors and urea detection devices to identify specific components in freezing conditions, the system activates heating elements partially and selectively, avoiding unnecessary heat exposure that would accelerate degradation of resistive elements.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If heating elements are activated when components do not contain urea, then components are heated, but power is consumed needlessly and resistive elements degrade

Engineering Contradiction:

Improveheating of urea-containing componentsVSAvoidunnecessary power consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The system incorporates urea detection devices and temperature sensors that provide real-time feedback about the presence of urea and thermal conditions in various components. This feedback mechanism allows the control unit to make informed decisions about heating element activation, ensuring that heating is applied only when both urea is present and freezing conditions exist, thereby eliminating unnecessary power consumption.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system applies heating locally and selectively to specific components based on their actual need. Temperature sensors and urea detection devices identify which components are in freezing conditions and contain urea, then activate heating elements only at those specific locations, rather than uniformly heating all components throughout the system.

Inventive Principle:

Principle #3Local quality

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 reduces unnecessary power consumption and extends the lifespan of resistive elements by selectively heating only the components in contact with urea, optimizing energy use and preventing premature degradation.

Implementation Method 1

heating devices that involve either specific heating elements... it is known to put resistive heating elements inside the tank containing the urea solution

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS8448426B2Method for heating an SCR system using resistive heating elements

Publication Date: 2013.05.28 PLASTIC OMNIUM ADVANCED INNOVATION & RES SA

AI summary

Method for heating a urea SCR system using at least two resistive heating elements (R1, R2), one of which (R1) is intended for heating one or some (part(s) of) component(s) always in contact with a substantial amount of urea and the other (R2) is intended for heating one or some (part(s) of) component(s) which are sometimes not in contact with a substantial amount of urea, and according to which, when starting the system in freezing conditions, the resistive element R1 is activated but the resistive element R2 is activated only when its component is actually in contact with a substantial amount of urea.