Methyl Paraffin Heat Transfer Fluids for Immersion Battery Cooling
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Solution Overview
Problem
Current heat transfer fluids used in electric vehicles are unsuitable for direct immersion with batteries and electric motors due to electrical conductivity, leading to potential shorting and failure, and lack a suitable combination of high flash point, low pour point, and effective cooling efficiency, limiting thermal management and vehicle performance.
Innovation Solution
Development of methyl paraffin-based heat transfer fluids derived from linear alpha olefin dimers, synthesized using metallocene catalysts, offering high flash points, low pour points, and efficient cooling properties, suitable for direct immersion or circulation with electric vehicle components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional heat transfer fluids (aqueous glycol solutions) are used for cooling electric vehicle components, then cooling efficiency is improved, but electrical conductivity causes shorting and failure when in contact with batteries or motors
Solution Approach 1:
The patent changes the fundamental parameter of electrical conductivity by replacing aqueous-based fluids with hydrocarbon-based fluids (isoparaffins, naphthenes, or aromatics). These alternative fluids have inherently low electrical conductivity, eliminating the shorting risk while maintaining acceptable heat transfer properties through careful selection of hydrocarbon types and ratios
Solution Approach 2:
The invention uses composite heat transfer fluids comprising multiple hydrocarbon components (isoparaffins, naphthenes, and/or aromatics) in specific ratios. This composite approach allows optimization of both thermal properties and electrical insulation characteristics, achieving a balance that neither single-component fluid could provide alone
2Object-affected harmful factors
If heat transfer fluids with high flash point are selected for safety, then fire risk is reduced, but cooling efficiency decreases
Solution Approach 1:
The patent optimizes the flash point parameter by selecting hydrocarbon components with inherently high flash points (aromatics >100°C, naphthenes >80°C, isoparaffins >60°C) and adjusting their ratios. Simultaneously, the thermal properties are optimized by selecting specific molecular weights and structures, achieving a balanced formulation that meets both safety and cooling requirements
Solution Approach 2:
The composite fluid formulation combines hydrocarbon types with different flash points and thermal properties. By carefully controlling the ratios (e.g., aromatics 10-50%, naphthenes 30-60%, isoparaffins 20-50%), the invention achieves a synergistic effect where the mixture maintains high flash point for safety while preserving adequate heat transfer efficiency for cooling
3Temperature
If conventional cooling strategies (phase change materials, heat dissipation fins, air cooling) are used, then cooling capability is limited, but vehicle performance is maintained
Solution Approach 1:
The invention employs hydraulic cooling using circulating liquid heat transfer fluids instead of air cooling or phase change materials. This liquid-based approach provides superior heat transfer coefficients and more effective thermal management, enabling better cooling capability without the weight penalty of heat dissipation fins or the performance limitations of air cooling
Solution Approach 2:
The patent optimizes multiple parameters of the heat transfer fluid including viscosity, specific heat capacity, thermal conductivity, and density by selecting specific hydrocarbon components and ratios. These parameter optimizations enable the fluid to achieve high cooling efficiency that directly supports improved vehicle performance through better thermal management of powertrain components
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 methyl paraffin-based fluids provide effective thermal management within the operating temperature range of electric vehicle batteries, preventing failure and enhancing vehicle performance, while being environmentally friendly and safe.
Implementation Method 1
effective cooling of the batteries of an electric vehicle through direct cooling fluid contact
Implementation Method 2
All batteries generate heat as they charge or discharge. The more rapid the rate of charge or discharge becomes, the greater the amount of heat generated per unit time
Data Source
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AI summary
Methyl paraffins formed by hydrogenating one or more LAO dimers comprising a vinylidene moiety or a trisubstituted olefin moiety may have advantageous heat transfer properties, particularly when incorporated within an electric vehicle. For example, methyl paraffins produced upon hydrogenating LAO dimers formed from one or more C6-C12 LAOs, particularly in the presence of a Hf metallocene catalyst system, may contain 12-24 carbon atoms, and collectively have a flash point of about 130°C or above, a pour point of about -42°C or lower, a thermal conductivity at 80°C of about 0.165W/M.K or higher, and a Mouromtseff number ranging from about 17.000 to about 27.000kg/(s22.m06.K) at 80°c: Heat transfer fluids comprising such methyl paraffins may be placed in contact with a heat-generating component, such as a battery and/or motor of an electric vehicle, or within a similar type of battery system, including immersive configurations for a battery.