UL9540A Heat Spread Test Device

The core of the UL9540A heat spread test device is to simulate various extreme situations that energy storage batteries may encounter in actual applications, especially thermal runaway scenarios. Thermal runaway refers to the phenomenon that the temperature inside the battery rises sharply due to factors such as short circuit, overcharge, over discharge, external high temperature, etc., which in turn causes the chemical reaction inside the battery to get out of control. The UL9540A test system is based on the theory that pure combustion calories are proportional to the amount of oxygen burned. Every 1KG of oxygen burned will produce 13.1 MJ/kg of gas. During the test, the system will measure key indicators such as gas heat emission, ignition time, oxygen consumption rate, CO and CO2 generation rate, and gas flow.

System composition

The UL9540A heat spread test device consists of several key parts, including test device, smoke exhaust duct, wind speed control system, smoke sampling and pretreatment system, gas analysis system, smoke density collection system, gas control system and data acquisition computer analysis system. Each part plays a vital role to ensure the accuracy and reliability of the test results.

Test device: used to place the energy storage battery samples to be tested, which can simulate the working conditions of the battery in actual applications.

Smoke exhaust duct: responsible for discharging the smoke generated by combustion out of the test area to avoid harm to the test environment and personnel.

Wind speed control system: used to adjust the wind speed in the test area to ensure the consistency of test conditions.

Smoke sampling and pretreatment system: collect smoke samples from the smoke exhaust duct and pretreat them to remove impurities and moisture for subsequent gas analysis.

Gas analysis system: use advanced gas analyzers to measure the concentration and content of gases such as oxygen, CO, CO2, etc. in the smoke.

Smoke density collection system: used to measure the density of smoke and evaluate the intensity of the combustion process.

Gas control system: responsible for controlling the gas supply during the combustion process to ensure the accuracy and safety of the test.

Data acquisition computer analysis system: through professional software, real-time data collection and analysis of the test process, generate a detailed test report.

Test process

The test process of the UL9540A test system is rigorous and complex, mainly including the following steps:

1. Sample preparation: Select representative energy storage battery samples to ensure that their status meets the test requirements. The samples need to meet the actual use conditions of the battery energy storage system and be assembled and connected according to certain specifications.

2. Pretreatment: Pre-treat the samples according to the test standards, such as charging and discharging, to ensure that they are in a stable state before testing.

3. Thermal runaway trigger: trigger battery thermal runaway by external heat source or internal short circuit. This step is the key to the test, and the triggering conditions need to be precisely controlled to ensure the accuracy and repeatability of the test.

4. Combustion heat release measurement: Use professional combustion heat release measurement equipment to monitor and record data such as heat release rate and flame spread speed during battery combustion in real time. These data are important indicators for evaluating battery safety performance.

5. Toxic gas analysis: Collect and analyze the types and concentrations of toxic gases generated during the combustion process, and evaluate their potential hazards to the environment and human body.

6. Result evaluation: Based on the test data, evaluate the safety performance of the energy storage battery under thermal runaway conditions to determine whether it meets the requirements of the UL9540A standard. The evaluation results will be used to guide the design and improvement of the battery energy storage system.

The UL9540A test not only focuses on the safety performance of the battery cell level, but also covers the tests at the module level, cabinet level, and installation level. The battery cell level test heats the battery cell in a constant volume combustion bomb and triggers thermal runaway. The gas composition of the thermal runaway is analyzed by gas chromatography, and then the explosion limit, explosion pressure, and burning rate test of the thermal runaway gas are carried out. The module level test heats the battery cell in the module and triggers thermal runaway, resulting in heat spread to other battery cells. The gas released by the module after thermal runaway is comprehensively analyzed through a variety of precise gas analysis instruments. Cabinet-level testing focuses on the behavior of cells inside modules installed in a battery cluster under thermal runaway conditions. Installation-level testing is used to evaluate the effectiveness of sprinkler and fire protection systems installed in accordance with code requirements.