Hybrid Vehicle Cooling System with Multi-Circuit Temperature Control

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Solution Overview

Problem

Hybrid vehicles require efficient cooling systems that can manage varying operating temperatures for combustion engines, electrical machines, energy storage, and cab spaces with a minimal number of components, as existing systems are inefficient in handling different temperature demands.

Innovation Solution

A multi-circuit cooling system with distinct coolants and a common refrigeration circuit for indirect cooling of the electrical energy storage and cab space, utilizing a second coolant to cool the electrical machine and refrigerant condenser, and a third coolant for the cab space, allowing for individual temperature control of components and reduced component count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If separate cooling systems are used for combustion engine, electrical machine, and cab space, then each component can be cooled to its optimal temperature, but the number of components and system complexity increases

Engineering Contradiction:
Improveoptimal operating temperatureVSAvoidnumber of cooling components
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines multiple cooling functions into a single integrated cooling system that serves the combustion engine, electrical machine, and cab space simultaneously. The system uses one coolant circulation loop with a radiator that can cool all three components by directing coolant flow to different heat exchangers connected to the same circulation system, thereby reducing the number of separate cooling components while maintaining optimal temperature control for each component.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling system is designed with multi-functionality to perform diverse cooling tasks using a single system. The coolant circulation system can simultaneously or selectively cool the combustion engine through its jacket, the electrical machine through a dedicated heat exchanger, and the cab space through the radiator, making one system universal for multiple cooling purposes.

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

2Device complexity

If a common refrigeration circuit is used for electrical energy storage and cab space cooling, then the number of components is reduced, but temperature control precision for different components may be compromised

Engineering Contradiction:
Improvenumber of refrigeration componentsVSAvoidtemperature control precision
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The cooling system is segmented into multiple independent cooling circuits, each with its own coolant circulation loop and control mechanisms. The first circuit cools the combustion engine, the second circuit cools the electrical machine, and the third circuit (refrigeration system) cools the electrical energy storage and cab space. This segmentation allows each circuit to be optimized for its specific temperature requirements while maintaining overall system efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each cooling circuit is designed with local quality characteristics tailored to the specific thermal requirements of the components it serves. The combustion engine cooling circuit operates at higher temperatures, the electrical machine cooling circuit maintains moderate temperatures, and the refrigeration circuit provides low-temperature cooling for the electrical energy storage and cab space, ensuring each component receives cooling appropriate to its optimal operating conditions.

Inventive Principle:
Principle #3Local quality

3Temperature

If multiple independent cooling circuits are used for different components, then individual temperature optimization is achieved, but system complexity and component count increase

Engineering Contradiction:
Improveindividual temperature optimizationVSAvoidnumber of coolant circuits
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The patent merges three separate cooling circuits into a single integrated cooling system that uses one coolant circulation loop to serve all cooling needs. The system includes a pump that circulates coolant through multiple heat exchangers connected in parallel or series, allowing the same coolant to cool the combustion engine, electrical machine, and cab space sequentially or simultaneously, thereby reducing the quantity of coolant and number of circuits while maintaining individual temperature optimization through controlled flow distribution.

Inventive Principle:
Principle #5Merging (Combining)

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

The system achieves efficient cooling of hybrid vehicle components by using separate coolants and a shared refrigeration circuit, optimizing temperature control and reducing the number of components needed, thereby enhancing operational efficiency and flexibility.

Implementation Method 1

The third coolant can be cooled by a refrigeration circuit to a lower temperature than the temperature of the ambient air

Methodology Applied
Scientific EffectRefrigeration cycle: Heat Exchanger

Implementation Method 2

The refrigerant in the refrigerant circuit is cooled by the second coolant in the second circuit in a condenser

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

the refrigerant is cooled in the condenser (15) to a temperature at which it condenses... The refrigerant is directed from the condenser (15) to an evaporator (25) where it cools the third coolant in the third circuit (20)

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3482053B1A cooling system for a hybrid vehicle
Publication Date: 2020.12.23 SCANIA CV AB
  • EP3482053B1 patent drawingFigure 1
  • EP3482053B1 patent drawingFigure 2
  • EP3482053B1 patent drawingFigure 3

AI summary

The present invention relates to a cooling system for a hybrid vehicle (1) powered by a combustion engine (2) and an electrical machine (3). The cooling system comprises a first circuit (4) with a first circulating coolant which is cooled in a first radiator (7) before it cools the combustion engine (2), a second circuit (11) with a second circulating coolant which is cooled in a second radiator (19) to a lower temperature than the first coolant before it cools the electrical machine (3), and a refrigerant circuit (16), The cooling system comprises a third circuit (20) with a third circulating coolant cooled by refrigerant in a chiller (25) of the refrigerant circuit (16) to a lower temperature than the second coolant before it cools an electrical energy storage (18) and a cab space (33) in the vehicle (1).