U-Type Battery Pack Cooling Structure for Electric Bicycles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing U-type battery packs for electric vehicles experience significant temperature deviations among cells, leading to uneven cell lifespan and the need for entire pack replacement when some cells fail, due to inefficient heat dissipation.
Innovation Solution
A U-type battery pack cooling structure where the coolant is introduced and discharged in opposite directions, with a specific ratio of entrance and exit flow rates and areas, optimized by the equation 1.65 × exit_flow_rate / entrance_flow_rate = C × exit_area / entrance_area, where C ranges from 0.8 to 1.2, to minimize temperature deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a U-type cooling channel structure is used with coolant flowing in opposite directions, then heat dissipation is improved, but temperature deviation among cells increases
Solution Approach 1:
The patent applies parameter changes by optimizing the flow rate ratio (C value between 0.8-1.2) and the area ratio of cooling channel entrances/exits to control coolant distribution. This resolves the contradiction by adjusting physical parameters to achieve both effective heat dissipation and uniform temperature distribution across cells.
Solution Approach 2:
The patent implements local quality by creating non-uniform coolant flow distribution through strategically designed slit configurations and flow rate control at different locations. This ensures that cells in different positions receive appropriate cooling, maintaining temperature uniformity while preserving the heat dissipation benefits of the U-type structure.
2Duration of action of stationary object
If cooling channels are provided to remove heat from cells, then cell lifespan is extended, but temperature deviation among cells increases
Solution Approach 1:
The patent uses parameter changes by controlling the flow rate ratio (C=0.8-1.2) and area ratios of cooling channels to optimize coolant distribution. This resolves the contradiction by adjusting these parameters to extend cell lifespan through effective cooling while maintaining uniform temperature across all cells.
Solution Approach 2:
The patent implements feedback control by using temperature sensors to monitor cell temperatures and adjusting coolant flow rates accordingly. This ensures that all cells remain within optimal temperature ranges, extending lifespan while preventing temperature deviation that would reduce reliability.
3Temperature
If coolant flow rate is increased to improve cooling, then heat dissipation is enhanced, but temperature deviation among cells increases
Solution Approach 1:
The patent applies parameter changes by optimizing the flow rate ratio (C value between 0.8-1.2) rather than simply increasing absolute flow rate. This resolves the contradiction by controlling the distribution characteristics of coolant flow, achieving effective cooling while maintaining uniform temperature across cells.
Solution Approach 2:
The patent implements local quality by controlling coolant flow distribution to different cell regions through slit configurations and flow rate management. This ensures that cells receive cooling proportional to their thermal needs, maintaining temperature uniformity while achieving effective heat dissipation.
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 achieves a temperature deviation of no more than 5 degrees among cells, ensuring uniform cell performance and extending the battery pack's lifespan by maintaining consistent operation within a stable temperature range.
Implementation Method 1
the coolant introduced through the side 32 subsequently passes through the slits 34, spaces between the cells 20, and the slits 44, and is then discharged out through the side 42. In this procedure, the coolant absorbs heat from the cells 20, thereby cooling the cells 20.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A battery pack for an electric vehicle has a cooling structure in which a coolant introduced through a first cooling channel cools cells and is then discharged through a second cooling channel. The cooling structure has a U-type structure in which the coolant is introduced and discharged in opposite directions. An entrance of the first cooling channel and an exit of the second cooling channel satisfy an equation in relation to an entrance flow rate and an exit flow rate. Since the temperature deviation among cells is set very small, the life of a battery pack may be elongated. Also, since a ratio of an exit area to an entrance area of a cooling channel may be quantitatively calculated according to an equation, it becomes very easy to design a battery pack.