Pressure Vent Assembly for Thermal Runaway Gas Equalization
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Solution Overview
Problem
Existing pressure relief assemblies are unable to accommodate high pressures and temperatures associated with thermal runaway events in sealed casings containing chemical reactors, such as batteries or fuel cells, which can lead to damage and structural failure.
Innovation Solution
A pressure accommodating assembly with a gas-permeable membrane and a pressure relief valve that allows gases to flow from a high-pressure side to a low-pressure side, maintaining structural integrity at temperatures up to 500°C and withstanding significant pressure differentials, featuring a semi-permeable membrane and a robust valve configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing pressure relief assemblies are used, then the structure is simple and easy to manufacture, but they cannot accommodate high pressures and temperatures during thermal runaway events
Solution Approach 1:
The pressure relief assembly is divided into distinct functional segments: a gas permeable membrane for pressure equalization, a pressure relief valve for emergency relief, and a body structure. This segmentation allows each component to be optimized for its specific function while working together to handle high pressure and temperature conditions.
Solution Approach 2:
The assembly uses a gas permeable membrane made from materials that maintain integrity at high temperatures while allowing gas passage. The combination of different materials (membrane, valve components, body) creates a composite structure that can withstand thermal runaway conditions better than single-material designs.
2Reliability
If a gas permeable membrane is added to allow gas flow, then pressure equalization is improved, but the assembly complexity increases
Solution Approach 1:
The gas permeable membrane serves multiple functions: it allows pressure equalization during normal operation, prevents liquid ingress, and maintains structural integrity during thermal events. The pressure relief valve similarly provides both sealed containment and emergency pressure relief functions, reducing the need for additional specialized components.
Solution Approach 2:
The gas permeable membrane is implemented as a thin film structure that is flexible enough to respond to pressure differentials while maintaining its selective permeability properties. This thin-film approach allows gas passage while blocking liquids, achieving pressure equalization without requiring complex mechanical structures.
3Reliability
If the pressure relief valve is biased to closed position to block gas flow, then containment is improved, but the ability to respond to pressure differentials requires additional mechanism complexity
Solution Approach 1:
The pressure relief valve uses a biasing mechanism (such as a spring) that automatically maintains the valve in the closed position during normal operation, providing sealed containment without active control. When pressure differential exceeds the biasing force, the valve automatically opens to relieve pressure, and then automatically closes when pressure equalizes, requiring no external control systems.
Solution Approach 2:
The valve design allows the biasing force to be adjusted to match expected operating pressure differentials. By changing the spring constant or pre-compression of the biasing mechanism, the valve can be tuned to open at specific pressure thresholds, providing adaptive response to different thermal runaway scenarios without changing the basic mechanism.
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 assembly effectively manages pressure differentials and high temperatures, maintaining structural integrity and operational functionality during thermal runaway events, allowing gases to permeate and equalize pressure while preventing liquid ingress and withstanding extreme conditions.
Implementation Method 1
a gas permeable membrane coupled to the body and configured to allow gases to permeate therethrough to thereby move from the first side to the second side
Implementation Method 2
the pressure relief valve is biased to a closed position to generally block a flow of gases therethrough and is configured to move to an open position when there is a predetermined pressure differential thereacross
Data Source
AI summary
A system including a pressure accommodating assembly having a body with a first side and a second side. The assembly further includes a gas permeable membrane coupled to the body and configured to allow gases to permeate therethrough to thereby move from the first side to the second side. The assembly also includes a pressure relief valve coupled to the body, wherein the pressure relief valve is biased to a closed position to generally block a flow of gases therethrough and is configured to move to an open position when there is a predetermined pressure differential thereacross to allow gases to flow therethrough to move from the first side to the second side. The pressure accommodating assembly is configured to maintain its structural integrity after being exposed to a temperature of about 500° C.