Vehicle Cooling Circuit Deaeration Without Coolant Mixing

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Solution Overview

Problem

Existing cooling systems for vehicles with multiple cooling circuits face challenges in maintaining different temperature levels and preventing air bubble accumulation, which can damage pumps, while requiring costly and space-consuming deaeration lines.

Innovation Solution

A cooling system with separate deaeration devices for each circuit, connected to a common expansion tank via static lines, allowing air bubbles to migrate upwards without mixing coolant, thus maintaining temperature differences and eliminating the need for additional deaeration lines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate deaeration lines are used for each cooling circuit, then air bubbles can be effectively removed from the coolant, but the system becomes more complex and requires additional components and space

Engineering Contradiction:
Improveair bubble removal efficiencyVSAvoidnumber of deaeration lines
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the deaeration functions of multiple cooling circuits into a single common deaeration chamber. Instead of having separate deaeration lines for each cooling circuit, the invention merges them so that air bubbles from different circuits accumulate together in one chamber, simplifying the overall system architecture while maintaining effective deaeration

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common deaeration chamber serves multiple cooling circuits simultaneously, making it a multi-functional component. This universal deaeration solution handles air removal for both the first and second cooling circuits through a single device, reducing the total number of components needed

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

2Reliability

If coolant flows continuously from the first cooling circuit to the expansion tank for deaeration, then air bubbles are removed effectively, but the temperature difference between cooling circuits is compromised

Engineering Contradiction:
Improvedeaeration effectivenessVSAvoidtemperature difference between circuits
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention segments the deaeration process by providing separate deaeration chambers or deaeration paths for each cooling circuit within the common deaeration device. This allows air bubbles to be removed from each circuit independently while maintaining the thermal characteristics of each circuit, preventing temperature mixing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The common deaeration chamber acts as an intermediary that receives air bubbles from multiple cooling circuits without requiring coolant flow mixing. Air bubbles are extracted as a separate phase while the liquid coolant remains in its respective circuit, maintaining temperature differences through phase separation

Inventive Principle:
Principle #24Intermediary (Mediator)

3Volume of stationary object

If a dual chamber expansion tank is used for both cooling circuits, then space is saved and installation costs are reduced, but air bubble accumulation can damage pumps

Engineering Contradiction:
Improveexpansion tank spaceVSAvoidair bubble accumulation
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the air bubbles from the coolant stream in the common deaeration chamber before the coolant returns to the cooling circuits. By separating and removing the air phase independently, the system prevents air bubble accumulation in the expansion tank and potential damage to pumps while maintaining the compact dual-chamber expansion tank design

Inventive Principle:
Principle #2Taking out (Extraction)

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 efficient deaeration of coolant, prolongs pump longevity, and reduces installation costs by eliminating the need for separate deaeration lines, while maintaining optimal temperature levels in each circuit.

Implementation Method 1

a deaeration device, located at a lower position than the expansion tank and connected to said expansion chamber via a static line, in order to allow air bubbles separated from the coolant in the deaeration device to migrate upwards in the static line towards the expansion chamber

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

The resulting total volume increase of the coolant in the cooling circuit depends on the original coolant volume and the temperature increase. In order to prevent the pressure from increasing too much in the cooling circuit, the cooling circuit is provided with an expansion tank which can accommodate the surplus coolant volume generated in connection with the expansion of the coolant

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4153848B1Cooling system and vehicle comprising such a cooling system
Publication Date: 2025.12.10 SCANIA CV AB
  • EP4153848B1 patent drawingFigure 1~2
  • EP4153848B1 patent drawingFigure 3
  • EP4153848B1 patent drawingFigure 4

AI summary

A cooling system comprising: - a first cooling circuit (10) with a first coolant pump (12); - a second cooling circuit (20) with a second coolant pump (22); - an expansion tank (30) provided with an expansion chamber (31) for accumulation of coolant, wherein this expansion chamber is connected to the second cooling circuit (20) in order to allow the expansion chamber to receive coolant from the second cooling circuit; and - a deaeration device (40) arranged in the first cooling circuit for separation of air bubbles from the coolant circulating therein. The deaeration device (40) is located at a lower position than the expansion tank (30) and connected to said expansion chamber (31) via a static line (5) in order to allow air bubbles separated from the coolant in the deaeration device to migrate upwards in the static line towards the expansion chamber.