Discussion on the structural design and safety of bess container energy storage

2024-07-17

As global energy consumption continues to increase, energy prices continue to rise. At the same time, with the continuous introduction of environmental protection policies in various countries, the global demand for clean energy such as photovoltaic and wind power generation has surged.
However, photovoltaic or wind power generation is unstable and cannot be stored, and has high environmental requirements, while the power supply needs to be continuous, stable and reliable. The emergence of bess container energy storage has greatly improved the power supply stability of new energy power generation systems, making clean energy truly practical.

However, the lithium batteries used in bess containers are dangerous goods. The continuous fire incidents of bess containers energy storage in the past two years have brought huge economic losses to society and made people doubt the application of bess containers energy storage.

The structural safety and operational safety of bess container energy storage systems are key factors to ensure the stable operation of power systems and the safety of life and property of personnel.

In this article, we will discuss in detail the structural safety, operational design safety, battery pack, and battery cluster design safety of bess container energy storage containers.

1.Bess container Energy storage-structural safety design

Material selection:

Select suitable building materials, considering their durability, corrosion resistance and mechanical strength.

Modular design:

Modular design is adopted to divide the energy storage system into multiple independent modules, each module contains a certain number of batteries and corresponding management units. This design facilitates the expansion and maintenance of the system, and also improves the reliability and safety of the bess container system.

Battery module-structural safety:

All design schemes adopt flame-retardant material schemes. Voltage collection points are arranged on each battery cell, and temperature collection points are reasonably allocated to jointly realize real-time and reliable monitoring of the operating status of the battery system.

Battery cluster-structural safety:

Protective insulation materials are added at the bottom support position of the battery cluster level to enhance insulation and protection characteristics. Additional cooling ducts are configured to achieve efficient temperature control and improve system safety performance. Temperature collection points are arranged at the connection copper bar position to judge the connection status in real time based on the temperature rise.

System level - structural safety:

The pressure relief port of the gas fire extinguishing system protection area refers to the device that automatically starts to release pressure when the pressure value in the protection area reaches the specified value when the fire extinguishing agent is sprayed in the gas fire extinguishing system. It is referred to as the pressure relief port, also known as the automatic pressure relief device, and is an essential equipment for the gas fire extinguishing system. Due to the good diffusion performance of the gas fire extinguishing agent, if the enclosure structure is incomplete, the fire extinguishing agent will flow out from the opening, resulting in the fire extinguishing concentration not being guaranteed, affecting the fire extinguishing effect. However, the increase in concentration will lead to an increase in the air pressure in the fire extinguishing area, and the enclosure structure is at risk of being damaged. The pressure relief device consists of a window body and a window leaf, which is mainly installed on the exterior wall of the building. It is usually closed. When a fire occurs, the fire extinguishing system releases the fire extinguishing agent and the air pressure in the fire extinguishing area increases. The pressure difference between the inside and outside of the window leaf of the pressure relief device is formed. When it reaches a certain value, the window leaf is pushed open, thereby maintaining a certain fire extinguishing concentration in the fire extinguishing area and protecting the enclosure structure from damage. According to the requirements of the specification, different building spaces require pressure relief devices with different pressure relief areas. The pressure relief area can be calculated based on the compressive strength of the fire extinguishing area enclosure structure and the injection rate of the fire extinguishing agent and a specific coefficient.

Mechanical analysis:

Perform detailed mechanical calculations and simulations to ensure that the structure can withstand the expected loads, including static loads and dynamic loads (such as wind loads, snow loads, etc.).

Fire protection performance:

Use fire-proof materials and designs that meet the standards to improve the fire protection performance of bess container the system.

Fire protection system design:

Implement graded fire warning and fire extinguishing strategies, including automatic power off and start-up of fire extinguishing systems.

Thermal management control:

Control the temperature in the bess container through air conditioning, thermal management design, insulation layer and other measures to ensure the normal operation of the battery pack and supporting electrical equipment.

Bess container system installation layout:

Meet the fire protection distance or firewall requirements specified in local standards to ensure the safety of the installation layout

Earthquake-resistant design:

For bess container systems located in seismic zones, earthquake-resistant design needs to be considered to ensure that the structure remains stable during an earthquake.

Thermal expansion and contraction:

Consider the thermal expansion coefficient of the material, and leave enough space in the design to cope with the thermal expansion and contraction caused by temperature changes.

Anti-corrosion measures:

Take appropriate anti-corrosion measures, such as coating, cathodic protection, etc., to extend the service life of the structure.

bess container has anti-corrosion measures

2. Key points of operational safety design

Electrical design:

Ensure that the design of the electrical system complies with safety regulations, including insulation, short-circuit protection, overload protection, etc.

Control system:

Design an efficient control system to ensure that the bess container system can be safely started, stopped and isolated under abnormal conditions.

Cooling system:

Design an effective cooling system to prevent equipment overheating and ensure safe operation.

Multi-level monitoring:

The battery system is equipped with a multi-level battery management system to collect various parameters such as battery voltage and temperature in real time for real-time monitoring and judgment.

xcessive temperature: The battery temperature is higher than the threshold point.
Excessive temperature rise: Rapid temperature rise occurs within a unit time (seconds).
Excessive temperature difference: A large temperature difference occurs inside the system.
Voltage fluctuation: Rapid changes in voltage and temperature acquisition.
Abnormal current: Abnormal current characteristics.
Monitoring alarm, power limit protection, shutdown, thermal runaway alarm, etc.

bess container has multiple levels of monitoring

Emergency plan:

Develop a complete emergency response plan and recovery strategy to deal with emergencies. Through multiple composite fire detection systems, early warning, timely intervention of the fire extinguishing system, effectively avoiding heat spread.

bess container fire extinguishing system

Passive protection:

Efficient ambient temperature control: Active temperature control management system design, timely export of heat emitted by the battery, to ensure that the battery works in a suitable temperature range.
Perfect structural design: Design reasonable layout plan and safety protection spacing
Perfect electrical design and selection: Ensure safe operation of the battery, once a short circuit occurs, it can quickly fuse and disconnect the circuit in time to reduce the risk of thermal runaway
Active protection: Use gas fire extinguishing system, full flooding fire extinguishing method, to ensure that when the battery catches fire, the fire extinguishing agent can quickly fill the entire protection area through the pipe network system, flood the fire point, and improve the pertinence and reliability of the fire extinguishing system. The design plan has an explosion-proof pressure relief design to ensure bess container safety.

Only by ensuring the safety and stability of the bess container system can the energy storage system truly bring value to customers. HT INFINITEPOWER adopts a unique three-level architecture management system, cloud platform security monitoring, module-level temperature control system, whole machine temperature control system, and fire detection system to ensure the safe and stable operation of the energy storage system.