2024-09-04
The primary role of carbon monoxide (CO) sensors in containerized lithium-ion battery energy storage systems is to effectively detect and provide early warnings in the initial stages of a battery fire, allowing for the implementation of appropriate fire suppression measures to prevent the fire from escalating.
As the global energy crisis intensifies, the development of the renewable energy industry has become an inevitable trend. Energy storage, as an emerging industry in the renewable energy sector, has already seen the establishment of storage stations in certain regions. These stations play a significant role in enhancing the power grid's capacity to integrate distributed energy sources, stabilizing voltage levels at the grid's endpoints, and serving as backup power sources during grid faults or maintenance. Additionally, energy storage stations hold substantial economic value in the power consumption phase of smart grid construction, with their safety and stability being critical to the overall economic performance of the system.
Containerized lithium-ion battery energy storage systems, as a new type of energy storage equipment, offer high power density, high energy density, long lifespan, high reliability, and strong environmental adaptability. They have broad application prospects on the power generation side, the grid side, and the user side. In recent years, 100-megawatt-scale lithium-ion battery energy storage stations have been constructed and commissioned in regions such as Jiangsu, Henan, Hunan, Qinghai, and Fujian. These stations have played a crucial role in smoothing out fluctuations in renewable energy generation, enhancing the capacity to export clean energy, grid peak shaving, frequency regulation, and providing ancillary services. Large-capacity containerized lithium-ion battery energy storage systems are becoming a trend for future development.
These systems use standard containers to house lithium-ion batteries, battery management systems, monitoring systems, air conditioning systems, fire protection systems, and distribution systems, resulting in highly integrated, large-capacity, and mobile energy storage devices. However, due to the low flash point, high chemical reactivity, and flammability of the electrolytic solvent in lithium-ion batteries, even with protective measures incorporated into the container design, it is still challenging to completely prevent thermal runaway within the energy storage battery caused by overcharging, over-discharging, short circuits, or mechanical damage, which could lead to explosions, fires, and other chain reactions. When one group of lithium-ion batteries experiences thermal runaway, it generates intense thermal shock that affects surrounding batteries, causing thermal runaway to spread. This process produces large amounts of flammable alkane gases, potentially resulting in severe fires or even explosions. In recent years, safety incidents at electrochemical energy storage stations have occurred frequently, leading to property damage and casualties. The safety issues of lithium-ion battery energy storage systems have become a significant factor limiting the rapid development of the industry, drawing increasing attention from all sectors of society.
Moreover, containerized lithium-ion battery energy storage systems feature a large number of battery cells in parallel clusters. Once a single lithium-ion battery cell undergoes thermal runaway, the high combustion temperature and rapid burning speed make fire suppression extremely difficult. The combustion characteristics vary significantly across different lithium-ion battery chemistries, and they produce large amounts of toxic and hazardous smoke, with a potential risk of explosion during the burning process. Once a fire occurs, the resulting intense combustion could lead to a complete fire or explosion of the entire energy storage system, posing enormous challenges to firefighting and rescue efforts.
When the battery safety valve opens, large amounts of gases and smoke are released, with the volume fraction of CO potentially increasing rapidly from 2.4×10^-6 to 190×10^-6. Additionally, gases such as CO2, CH4, and volatile organic compounds (VOCs) also see significant increases when the safety valve opens. Therefore, by utilizing relevant gas sensors, along with smoke detectors, fire detectors, and temperature sensors, and setting appropriate alarm thresholds based on the thermal runaway characteristics of the station’s batteries, multiple characteristic parameters can be coupled. When the parameters from different sensors reach the set thresholds, an alarm is triggered, enabling early detection and warning of lithium-ion battery fires, and allowing for corresponding control measures to prevent further escalation.
Furthermore, it is essential to select appropriate sensors and detectors based on their range and sensitivity and to establish redundant systems to ensure accurate response of the early fire detection and warning devices at the station.
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