Vehicle Engine Cooling Circuit Segmentation for Oil Heating

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Solution Overview

Problem

Existing cooling circuits for vehicle engines are ineffective in reducing fuel consumption and pollutant emissions during cold operation, as they fail to quickly reduce mechanical losses by friction and lower coolant temperatures.

Innovation Solution

A controlled thermostatic valve system that manages the cooling liquid circulation and a bypass circuit for lubricating oil, using solenoid valves to regulate oil flow through a turbocharger, allowing increased oil circulation at lower temperatures to accelerate lubricating oil heating and maintaining low coolant temperatures for reduced emissions and fuel consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the cooling liquid circulation is rapidly increased to lower coolant temperature for reducing emissions, then pollutant emissions are reduced, but the lubricating oil temperature cannot be quickly raised and mechanical losses by friction remain high

Engineering Contradiction:
Improvepollutant emissionsVSAvoidlubricating oil temperature
Core Design Contradiction:
Object-generated harmful factorsVSTemperature

Solution Approach 1:

The cooling circuit is segmented into multiple independent pathways: a first circuit for coolant circulation through the radiator, a second circuit for lubricating oil heating through the turbocharger, and a third circuit for coolant circulation through the heater. This segmentation allows each circuit to be optimized independently, enabling the oil to be heated rapidly while the coolant temperature is controlled separately for emission reduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The turbocharger body serves as an intermediary heat transfer component. It receives hot exhaust gases that heat the lubricating oil as it passes through the turbocharger bearings and housing. This intermediary mechanism enables rapid oil temperature increase without directly heating the oil through a separate heater, solving the contradiction between rapid oil heating and coolant temperature control.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If the cooling liquid circulation is restricted to maintain low coolant temperature, then emissions are reduced, but the overall system efficiency decreases due to inability to rapidly warm up lubricating oil

Engineering Contradiction:
ImproveemissionsVSAvoidsystem efficiency
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The system employs dynamic control of circulation pumps and valves to adjust flow rates based on operating conditions. The first circulation pump can operate independently from the second circulation pump, allowing the coolant flow through the radiator to be optimized for emission reduction while the oil circulation through the turbocharger is optimized for rapid heating, thereby maintaining high system efficiency without compromising emission control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the temperature parameters of different circuits independently. The coolant temperature is maintained at lower levels for emission reduction, while the lubricating oil temperature is rapidly increased through the turbocharger heating mechanism. This parameter differentiation allows the system to achieve both low emissions and high efficiency simultaneously.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a single cooling circuit is used for both coolant and lubricating oil, then device complexity is reduced, but the ability to independently control temperatures for emissions and friction reduction is lost

Engineering Contradiction:
Improvecircuit configurationVSAvoidemissions and mechanical losses
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The cooling circuit is segmented into multiple independent pathways: a first circuit for coolant circulation through the radiator, a second circuit for lubricating oil heating through the turbocharger, and a third circuit for coolant circulation through the heater. This segmentation allows each circuit to be optimized independently, enabling the oil to be heated rapidly while the coolant temperature is controlled separately for emission reduction.

Inventive Principle:
Principle #1Segmentation

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 solution accelerates the rise in temperature of the lubricating oil while maintaining low coolant temperatures, reducing engine emissions and fuel consumption, particularly NOx emissions, and ensuring passenger compartment comfort.

Implementation Method 1

passing through the turbocharger 13 to accelerate the rise in temperature of the lubricating oil

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

a liquid/oil exchanger 11 for cooling the lubricating oil under pressure circulating in the engine 1

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

under the action of a circulation pump 2 operating in a closed circuit

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 4

a thermostatic valve comprising an inlet receiving coolant coming from the engine and a coolant outlet connected to a cooling radiator

Methodology Applied
Scientific EffectThermostatic control:

Data Source

PatentEP1892389B1Device making it possible to control a circuit for circulation of a coolant liquid and a circuit for circulation of lubrication oil of a heat engine of a vehicle
Publication Date: 2009.02.11 PEUGEOT CITROEN AUTOMOBILES SA
  • EP1892389B1 patent drawingFigure 1~2
  • EP1892389B1 patent drawingFigure 3~4
  • EP1892389B1 patent drawingFigure 5

AI summary

The device has an oil/liquid exchanger (11) with a bypass line (23) connected to lubrication oil inlet and outlet of the exchanger. Flow of oil through the line is controlled by solenoid valves (24, 26) driven based on a temperature of a coolant e.g. water, at an inlet (4) of a thermostat (3). The valves occupy a position to stop lubrication oil circulation through the exchanger and to circulate the oil in the line at a temperature value. The valves take another position to stop the oil circulation in the line and to allow circulation of the oil in the exchanger at another temperature value.