Combustion Engine Cooling System with Dual-Temperature Valve Control

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Solution Overview

Problem

Conventional cooling systems for combustion engines and Waste Heat Recovery (WHR) systems face challenges in efficiently cooling the cylinder head and charge air, as they often require different coolant temperatures, leading to suboptimal thermal efficiency and increased fuel consumption.

Innovation Solution

A cooling system with a first valve device and a control unit that manages coolant flows to the cylinder block and cylinder head at different temperatures, allowing for independent temperature control and optimizing coolant distribution based on sensor data to achieve efficient cooling of both components and additional components like WHR systems and charge air coolers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a conventional cooling system directs coolant at a uniform temperature (80-90°C) to all parts of the combustion engine, then the cooling system is simple to operate, but the cylinder head achieves very high temperatures under heavy load due to receiving more heat energy from combustion processes than the cylinder block

Engineering Contradiction:
Improvecylinder head temperatureVSAvoidcooling system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The cooling system is segmented into two independent temperature control zones: one for the cylinder block and one for the cylinder head. Each zone has its own thermostat valve (first thermostat valve for block, second thermostat valve for head) that independently regulates coolant flow and temperature, allowing the cylinder head to be cooled to a lower optimal temperature while the block maintains higher temperature for friction reduction in bearings.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different temperature conditions are applied to different parts of the engine based on their specific thermal requirements. The cylinder head receives cooler coolant to manage its higher heat load from combustion, while the cylinder block receives warmer coolant to maintain optimal operating temperature for mechanical components. This local differentiation of thermal conditions optimizes overall engine performance.

Inventive Principle:
Principle #3Local quality

2Reliability

If the cooling system cools the working medium in the condenser of a WHR system to achieve high thermal efficiency, then the condensation temperature can be kept as low as possible, but the system cannot adapt to rapidly varying heat energy from exhaust gases

Engineering Contradiction:
ImproveWHR system thermal efficiencyVSAvoidcooling capacity adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The cooling system employs dynamic control through electronically controlled thermostat valves that can rapidly adjust their opening degree in response to varying thermal loads. The control unit continuously monitors temperature sensors and adjusts the coolant flow distribution dynamically, enabling the system to adapt to rapidly changing heat energy from exhaust gases while maintaining optimal condensation temperature for high WHR system efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates a feedback control mechanism where temperature sensors monitor the actual temperature conditions in the cylinder block, cylinder head, and condenser, and this information is fed back to the control unit. The control unit processes this feedback and adjusts the opening degree of the thermostat valves accordingly, ensuring the working medium in the condenser is cooled to the required condensation temperature while adapting to varying thermal loads from the engine.

Inventive Principle:
Principle #23Feedback

3Temperature

If coolant flow is directed entirely to the radiator to cool the cylinder head, then the cylinder head temperature decreases, but the cylinder block temperature also decreases which increases friction in bearings

Engineering Contradiction:
Improvecylinder head temperatureVSAvoidfriction in bearings
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The coolant flow is segmented into separate controllable paths for the cylinder block and cylinder head through the first and second thermostat valves. This segmentation allows independent temperature control where the cylinder head can be cooled more aggressively while the cylinder block maintains higher temperature, preventing increased friction in bearings while still achieving effective cylinder head cooling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different thermal conditions are applied locally to different engine components based on their specific requirements. The cylinder head receives cooler coolant to manage combustion heat, while the cylinder block receives warmer coolant to maintain optimal temperature for bearing operation. This local quality differentiation resolves the contradiction between cooling the head and preventing excessive friction in the block.

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 solution enables efficient cooling of the cylinder head to a lower temperature than the cylinder block, reducing fuel consumption, and maintains high thermal efficiency in WHR systems by adjusting coolant temperatures dynamically, thereby improving overall engine performance and thermal management.

Implementation Method 1

a radiator (7) for cooling of the coolant

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 2

A pump (5) circulates coolant in the cooling system

Methodology Applied
Scientific EffectPumping: Pump

Data Source

PatentEP3574195B1A cooling system for cooling of a combustion engine
Publication Date: 2023.10.11 SCANIA CV AB
  • EP3574195B1 patent drawingFigure 1
  • EP3574195B1 patent drawingFigure 2
  • EP3574195B1 patent drawingFigure 3

AI summary

The present invention relates to a cooling system for cooling of a combustion engine (2). The cooling system comprises a cylinder block inlet line (3a) configured to direct coolant to the cylinder block (3) of the combustion engine (2) and a cylinder block outlet line (3b) configured to receive coolant from the cylinder block (3) and a cylinder head inlet line (4a) configured to direct coolant at a second temperature (T2) to the cylinder head (4) of the combustion engine (2) and a cylinder head outlet line (4b) configured to receive coolant from the cylinder head (4). A first valve device (6) and a second (12) are configured to direct coolant at a first temperature (T) to the cylinder block (3) and coolant at a lower second temperature (T2) to the cylinder head (4)