With the expanding applications of lithium-ion battery energy storage systems (Battery Energy Storage Systems, BESS) across various industries, the risks of fires and explosions caused by thermal runaway have become critical safety issues that demand urgent solutions. Internationally, both the NFPA 68 explosion venting standard promoted by the U.S. National Fire Protection Association (NFPA) and the FM Data Sheet for lithium battery energy storage systems based on FM 5-33 highlight the inevitability of thermal runaway in Battery Energy Storage Systems. These standards require explosion venting measures to be incorporated into explosion-proof designs to mitigate the impact of internal gas deflagration on systems and surrounding facilities.

However, due to cost-saving measures in research and testing, Battery Energy Storage System manufacturers often cannot provide the test data required as input for NFPA 68 explosion venting area calculations. Additionally, current domestic regulations do not mandate thermal runaway explosion venting designs for Battery Energy Storage Systems, creating numerous challenges in data acquisition and standard selection. This article focuses on the FM 5-33 standard, exploring its practical challenges and feasible approaches in explosion venting area calculations while proposing corresponding solutions.

Explosion Venting Area Calculation Based on FM 5-33

Unlike the NFPA 68 method, which relies heavily on extensive test data, the FM 5-33 standard proposed by FM emphasizes practicality through the following strategies:

• Unified Parameter Method:
  When specific test data is unavailable, propane can be used as a representative gas for explosion venting area calculations. This approach provides a conservative yet safe design parameter.
• Cost Reduction:
  This method effectively reduces research and testing costs while demonstrating high practical feasibility in selecting vent panels and subsequent explosion-proof designs. It offers Battery Energy Storage System manufacturers a viable path to reduce risks while complying with standards.

Considerations for Explosion Venting Design

When designing explosion venting systems, the following factors must be comprehensively considered:

1. Venting Location:
   Vent openings should be placed as far as possible from areas with personnel activity and critical equipment to ensure that gases released during deflagration are smoothly discharged, preventing secondary damage to the surrounding environment and equipment.
2. Performance of Venting Devices:
   The performance of venting devices is crucial. Their response time and activation pressure must meet stable and reliable requirements to function effectively during emergencies.

Conclusion

To address the risks of thermal runaway and gas deflagration in Battery Energy Storage Systems, manufacturers must strike an optimal balance among gas parameters, structural design, standard compliance, and data availability. The loss-limiting structural design methods and propane parameter approach provided by FM 5-33 not only offer a high degree of safety but also provide an effective path for manufacturers looking to reduce research costs while quickly implementing explosion-proof designs.

The explosion venting area calculation services based on FM standards and ATEX-certified vent panels provided by Liansuo Building Technology represent an ideal solution for tackling thermal runaway challenges. These services help companies meet safety design requirements while effectively mitigating deflagration risks, thereby enhancing operational safety and overall regulatory compliance of Battery Energy Storage Systems.