Dielectric Fluid Spray Cooling for Battery Thermal Management
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Solution Overview
Problem
Existing battery pack cooling/heating systems for electric vehicles suffer from uneven cooling, high thermal resistance, and excessive use of dielectric liquid, leading to increased cost and weight.
Innovation Solution
A device using a dielectric fluid circuit with spray nozzles to directly contact the battery cells, minimizing the quantity of dielectric fluid required by spraying it onto the cell surfaces in the form of a film, jets, or droplets, and recycling it through a closed circuit with a heat exchanger for efficient heat recovery and temperature regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If batteries are immersed in dielectric liquid for cooling, then homogeneous cooling is achieved, but the quantity of dielectric liquid increases, leading to increased weight and cost
Solution Approach 1:
The patent segments the cooling approach by transitioning from complete immersion to targeted spraying. Spray nozzles are positioned between battery cells to deliver dielectric liquid only to specific hot spots on cell surfaces, rather than immersing all cells in liquid. This segmentation reduces the total quantity of dielectric liquid required while maintaining effective cooling where needed most.
Solution Approach 2:
The patent introduces a spatial dimension to the cooling system by using spray nozzles positioned in the gaps between cells. The dielectric liquid is delivered in a directed spray pattern (film, jets, or droplets) that covers the cell surfaces in the spaces between cells, utilizing the three-dimensional arrangement of cells to achieve homogeneous cooling without requiring liquid to surround all cells completely.
2Temperature
If heat exchangers with circulating coolant are used, then temperature regulation is achieved, but thermal resistance increases due to material thickness between coolant and cells
Solution Approach 1:
The patent extracts the dielectric liquid from the traditional heat exchanger configuration and applies it directly to the battery cell surfaces through spray nozzles. By removing the intermediate solid heat exchanger materials (cold plates, heat sinks) and using direct liquid-surface contact via spraying, the system eliminates the thermal resistance introduced by thick solid materials while maintaining temperature regulation capability.
Solution Approach 2:
The dielectric liquid serves as an intermediary medium that bridges the thermal gap between battery cells and the cooling system. Instead of relying on solid heat exchanger materials with inherent thermal resistance, the patent uses the sprayable dielectric liquid as a mobile intermediary that directly contacts cell surfaces, transfers heat efficiently, and can be circulated through the system to maintain temperature regulation.
3Temperature
If spray nozzles are positioned between battery cells, then direct contact cooling is achieved, but device complexity increases
Solution Approach 1:
The dielectric liquid performs multiple functions within the system: it serves as the cooling medium delivered by spray nozzles, acts as an electrical insulator between cells, and can be circulated through heat exchangers for temperature regulation. This multi-functionality reduces the need for separate specialized components, thereby limiting the increase in device complexity despite the addition of spray positioning infrastructure.
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 homogeneous cooling, reduces the amount of dielectric fluid needed, thus lowering the weight and cost of the battery pack, while maintaining efficient temperature control within a desired range.
Implementation Method 1
the direct contact established between the liquid and the cells
Implementation Method 2
fluid circulation or under static conditions with phase change
Implementation Method 3
under static conditions with phase change
Implementation Method 4
the fluid being intended to vaporize at least partially on the surface of the cells
Implementation Method 5
a heat exchanger for efficient heat recovery and temperature regulation
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A device for regulating the temperature of a battery comprising at least one energy storage cell, said device comprising a dielectric fluid circuit, said circuit comprising means for spraying the surface of said cell with said dielectric fluid.