Engine Cooling Circuit Control Using Predictive Thermal Modeling

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Solution Overview

Problem

Existing cooling systems for internal combustion engines struggle to accurately determine the thermal state of specific engine areas, especially during zero coolant flow phases, leading to inadequate temperature regulation and potential damage to critical components.

Innovation Solution

A control system that uses a combination of temperature sensors and statistical models, such as moving average autoregressive models, to determine the characteristic temperature of specific engine zones, allowing for precise control of the cooling circuit and flow cut-off mechanisms to maintain optimal engine temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the temperature sensor is positioned outside the cylinder head, then the cooling system can operate with simpler sensor installation, but the temperature measurement becomes unrepresentative during zero coolant flow phases

Engineering Contradiction:
Improvesensor installation simplicityVSAvoidtemperature measurement representativeness
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent introduces a predictive model as an intermediary that processes coolant temperature measurements and engine operating parameters to estimate the true engine temperature. This mediator compensates for the unrepresentative sensor readings during zero flow phases, allowing external sensor placement while maintaining measurement accuracy through computational correction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the coolant flow is cut off during cold start, then the engine temperature rises rapidly reducing fuel consumption, but the temperature of critical areas may become excessive causing reliability issues

Engineering Contradiction:
Improveengine warm-up speedVSAvoidcritical component thermal safety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback control system that continuously monitors engine temperature, coolant flow rate, and operating parameters. Based on this feedback, the control means dynamically adjusts the coolant flow cutoff timing and duration, extending or reducing the zero-flow phase to maintain critical areas within safe temperature ranges while maximizing fuel efficiency benefits.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system dynamically adapts the cooling strategy based on real-time engine conditions. The zero-flow phase duration is not fixed but varies according to engine load, ambient temperature, and thermal state, allowing optimal balance between rapid warm-up and thermal protection under different operating scenarios.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If a predictive model is used to estimate engine thermal state, then temperature characterization improves, but the system requires multiple input parameters and computational processing

Engineering Contradiction:
Improveengine thermal state characterizationVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The predictive model serves multiple functions simultaneously: it estimates critical area temperature for safety monitoring, determines optimal zero-flow phase timing for fuel efficiency, and provides thermal state feedback for control adjustments. This multi-functionality justifies the computational complexity by delivering comprehensive thermal management benefits from a single integrated model.

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

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

Enables accurate temperature characterization of critical engine areas, ensuring reliable operation and reducing fuel consumption and pollutant emissions by efficiently managing the cooling process, even during startup and zero coolant flow conditions.

Implementation Method 1

A cooling branch passes through a radiator making it possible to lower the temperature of the heat transfer fluid contained in the cooling circuit

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

a cooling circuit containing two branches. A cooling branch passes through a radiator making it possible to lower the temperature of the heat transfer fluid

Methodology Applied
Scientific EffectConduction (thermal): Conduction (thermal)

Data Source

PatentEP2494161B1System and method for controlling the cooling circuit of an internal-combustion engine
Publication Date: 2016.08.17 RENAULT SA
  • EP2494161B1 patent drawingFigure 1
  • EP2494161B1 patent drawingFigure 2
  • EP2494161B1 patent drawingFigure 3

AI summary

The invention relates to a method, during cold starting, for controlling a cooling circuit containing a heat-transfer fluid for an internal-combustion engine (i) installed in an automobile, the cooling circuit being provided, downstream from the internal-combustion engine (i), with a means (5) for interrupting the flow suitable for creating a discontinuity in the flow of heat-transfer fluid, initially in the off position, characterised in that said method includes the following steps, which involve: determining a typical temperature for the thermal condition of a specific area of the internal-combustion engine by means of applying a model according to the temperature inside the internal-combustion engine; and switching the means (5) for interrupting the flow into the on position if the typical temperature for the thermal condition of the specific area of the internal-combustion engine is higher than a maximum temperature.