Battery Pack Venting Mesh and Expansion Chamber for Fire-Safe Cooling
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Solution Overview
Problem
Existing power supply devices fail to efficiently combine both external fire prevention and improved cooling performance.
Innovation Solution
A power supply device that incorporates a battery block including a discharge valve that opens in response to an abnormality to discharge a jet substance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a cooling path with a filter or baffle plate is used to reduce the temperature of discharged gas to prevent external fire, then external fire prevention is improved, but cooling performance of the battery block deteriorates
Solution Approach 1:
The case is divided into multiple air holes (plurality of air holes) instead of using a single filter or baffle plate. Each air hole has a small opening size (≤4mm) to prevent external fire, while the collective total opening area of all air holes is made larger than the cross-sectional area of the guide clearance to ensure sufficient cooling airflow to the battery block.
Solution Approach 2:
Different regions of the case have different functions: the mesh portion with air holes provides fire prevention, while the expansion chamber provides cooling. The air holes are strategically positioned to allow cooling air to reach the battery block surface while the discharge valve position directs jet substance away from these holes.
2Object-affected harmful factors
If the opening size of air holes is reduced to prevent external fire, then external fire prevention is improved, but cooling airflow quantity deteriorates
Solution Approach 1:
The total opening area requirement is segmented across multiple air holes. Each individual air hole has a small opening size (≤4mm) to prevent external fire, but the plurality of air holes collectively provides a total opening area larger than the guide clearance cross-sectional area, ensuring sufficient total airflow quantity for cooling.
3Object-affected harmful factors
If a long cooling path is used to maintain jet substance temperature at 350°C or lower, then external fire prevention is improved, but device complexity increases
Solution Approach 1:
The harmful high-temperature jet substance is extracted and directed away from the cooling path through the discharge valve. The discharge valve opens in response to abnormality to discharge the jet substance, preventing it from entering the cooling path and eliminating the need for a long, complex cooling path.
Solution Approach 2:
The high-temperature jet substance that could cause external fire is converted into a beneficial cooling effect. The jet substance is directed to impinge on the battery block surface, providing localized cooling where it is most needed, while the air holes provide additional cooling airflow.
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
A power supply device that incorporates a battery block including a discharge valve that opens in response to an abnormality to discharge a jet substance.
Implementation Method 1
allows the jet substance discharged to the guide clearance and expanding adiabatically to flow into the expansion chamber
Implementation Method 2
allows the cooling air flowing into the expansion chamber through the plurality of air holes to be blown to a surface of the battery block
Data Source
Figure 1
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AI summary
To safely discharge a jet substance from battery cells to prevent an external fire and have improved cooling performance, a power supply device includes a battery block 10 including multiple battery cells 1 and a case 2 housing the battery block 10. The case 2 includes a mesh portion 40 having air holes 41 with an opening size (a) less than or equal to 4 mm through which cooling air to cool an internal component is drawn in, an expansion chamber 53 between an inner surface of the case 2 including the mesh portion 40 and the battery block 10, and a guide clearance 51 between the inner surface of the case 2 and the battery block 10. The air holes 41 have a total opening area larger than a cross-sectional area of the guide clearance 51. The power supply device allows the jet substance discharged to the guide clearance 51 and expanding adiabatically to flow into the expansion chamber 53 to be discharged outside the case 2 through the air holes 41, and allows the cooling air flowing into the expansion chamber 53 through the air holes 41 to be blown to a surface of the battery block 10.