Liquid Tank Heating via Recessed Element and Conductive Plastic

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Solution Overview

Problem

The challenge is to effectively heat a urea solution in a liquid tank for a motor vehicle without damaging the heating element and ensuring efficient heat transfer, given the geometry constraints and the corrosive nature of the urea solution.

Innovation Solution

A liquid tank design with an indentation on the outer shell to house a heating element, which is thermally connected to the tank shell via a thermally conductive plastic, allowing for effective heat transfer without direct contact with the urea solution, using a metallic heat-conducting element and electrical heating elements like PTC or resistance heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the heating element is inserted inside the liquid tank to heat the urea solution, then the heating effectiveness is improved, but the heating element is damaged by the urea solution

Engineering Contradiction:

Improveheating effectivenessVSAvoidheating element durability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent introduces a tank wall as an intermediary medium between the heating element and the urea solution. The heating element is positioned in a recess on the outer surface of the tank shell, heating the tank wall which then transfers heat to the urea solution through the tank wall material, preventing direct contact between the heating element and the corrosive urea solution

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The heating element is moved from the internal three-dimensional space of the tank to the external surface dimension. By positioning the heating element in a recess on the outer surface of the tank shell, the design changes the spatial arrangement from internal immersion to external surface mounting, allowing heat transfer through the tank wall rather than direct contact

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Loss of energy

If the heating element is positioned inside the liquid tank, then the heat transfer efficiency is improved, but the tank geometry and mounting options are limited

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidtank geometry constraints

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The tank wall serves as a thermal intermediary that enables heat transfer from the externally positioned heating element to the urea solution. This approach maintains effective heat transfer while eliminating the geometric constraints that would otherwise limit heating element placement within the tank interior

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of placing the heating element inside the tank as conventionally done, the patent inverts the arrangement by positioning the heating element on the outer surface of the tank shell in a recess, with heat transferring through the tank wall in the opposite direction of conventional internal heating

Inventive Principle:

Principle #13The other way round (Inversion)

3Power

If the heating element is placed inside the liquid tank, then the heating performance is improved, but the heating element is exposed to corrosive urea solution

Engineering Contradiction:

Improveheating performanceVSAvoidcorrosion damage

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The tank wall material acts as a protective intermediary barrier between the heating element and the corrosive urea solution. This intermediate layer maintains the heating performance by conducting heat effectively while simultaneously protecting the heating element from chemical corrosion and contamination

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the potential harm of urea solution exposure to the heating element into a benefit by using the tank wall as a protective barrier. The tank wall, which must already be chemically resistant to contain the urea solution, now also serves as a protective layer for the heating element, eliminating the need for additional corrosion protection measures

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 ensures effective heating of the urea solution, prevents damage to the heating element, and maintains efficient heat transfer by using a thermally conductive plastic and metallic heat-conducting elements, ensuring the urea solution remains unfrozen at low temperatures.

Implementation Method 1

a heating element which is arranged in the recess and which is designed to heat the liquid tank shell

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the radiator is thermally connected to a curved wall of the indentation in order to effectively heat the curved wall

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the heating element comprises a thermally conductive plastic to provide a thermally conductive connection between the heating element and the liquid tank shell

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3375997B1Liquid tank with a heating body

Publication Date: 2019.10.02 VERITAS AG

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AI summary

The present invention relates to a liquid tank (100) for holding liquid in a motor vehicle, comprising a liquid tank shell (101), wherein a recess (123) is formed in the liquid tank shell (101), which is accessible from an outer area (122) of the liquid tank shell (101); and a heating element (135) which is arranged in the recess (123) and which is configured to heat the liquid tank shell (101).