UL 9540A Test Method For Evaluating Thermal Runaway Fire Propagation In Battery

Introductions
Applies to the total amount of heat released by a single 21700 lithium battery during combustion; individual cells are 48mm in diameter and 80mm in height. 21700-5500mAh 3.6V/4.2V 19.8Wh.

Principle

It is designed on the basis of the oxygen consumption calculated from the oxygen concentration in the gas stream of the combustion products and the rate of heat release during the combustion products. The device can accurately measure the heat release rate during the combustion of a single 21700 lithium battery.

Application
Electrical & electronic product
Components and accessories of household appliances

Standards

1. Refer to UL9540A "Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems to evaluate the test method of thermal runaway fire propagation in battery energy storage systems" standard design;
2. Refer to GB/T16172-2007, ISO5660-1:2002 "Test Method for Heat Release Rate of Building Materials" standard.

Features

1.The control part adopts embedded industrial computer control, the signal collection and processing adopts 16-bit high-precision board card, the accuracy level can reach one per cent, stable performance, good repeatability.
2.Computer control interface: the use of high-grade equipment and instrumentation professional development software (Labview), rigorous interface, high degree of automation, all the cumbersome procedures and operations have been integrated into the computer, the response speed is very fast, easy to operate, user-friendly interface, foolproof operation.
3.Operating software: Windows xp interface, Labview style, perfect security mechanisms. Computer output data for combustion heat release rate, total heat release, smoke concentration. Real-time display of heat flow - time curve, total heat release rate - time curve, smoke production during the test.
4.We have many research institutes and scientific research units to co-operate with, such as: Sichuan Fire Research Institute of the Ministry of Emergency Management, State Grid Electric Power Research Institute and so on.

Technical parameters

1.Box structure: test and control box by the combination of analytical cabinets, analytical cabinets and experimental operation cabinets can be integrated design. The upper part of the test platform is installed with a tempered glass observation window as a protective screen, and the bottom of the observation window is empty as a pressure relief port to prevent gas explosion.

2.Sample trigger source:
①external heating trigger:
②Composition: constant pressure source + electric heating composition;
③constant pressure source: power 0~5kW continuously adjustable;
④electric heating plate: 5kw electric heating plate heating;
⑤Specification of electric heating plate: length 150mm, width 100mm.
⑥Explosion-proof frame 10mm steel plate, specification 200mm*200mm;
⑦ontrol mode: control the electric heater through a constant pressure source to achieve the sample external heating triggered thermal runaway.
⑧Heating trigger device installation position: the heating surface of the heating device will be in direct contact with the surface of the battery monomer.

3.Lithium battery overcharge trigger:
①Overcharge voltage: 0~10V adjustable;
②Overcharge voltage: 30A;.
③Over-charging power: 300VA.
④Explosion-proof frame: 10mm steel plate, specification 200mm*200mm;

4.Collection, measurement and control system:
①Composition: by the collection cover, smoke pipe, smoke exhaust fan, throttle orifice plate and differential pressure air velocity measurement device, thermocouple flue gas temperature measurement device, smoke temperature signal to the main control programme to participate in the experimental results of the data calculation, smoke exhaust device is located at the top of the cabinet.
②Axial fan: wind speed adjustable, in the standard temperature and pressure conditions, the exhaust system can make the exhaust volume (g / s): 0 ~ 50, precision (g / s): less than 0.1.
③Collecting hood: a conical body, smoke collection mouth for 450mm × 450mm, on a 150mm × 150mm square, a total height of 350mm, the bottom of the smoke collection hood and the distance from the surface of the specimen for (210 ± 50) mm
④Orifice plate flowmeter: the use of high-precision digital output, the output of 0-10v voltage signal through the I/0 plate speed module transformation, directly from the computer to control its flow.
⑤Throttling orifice plate: in the smoke collection hood and the inlet pipe is equipped with an inner diameter of (57 ± 3) mm throttle orifice plate, in order to homogenise the components of the gas flow;
⑥The gas is collected using a ring sampler, fitted in the collection hood (685±15) mm inside the fan intake duct. The ring sampler has 12 small holes with a diameter of (2.2±0.1) mm; to homogenise the gas stream components, the holes are in the opposite direction to the gas stream to avoid soot deposition.
⑦Measurement of airflow temperature; measured by an armoured thermoelectric leak with an external diameter of 1.5mm. Installed in the upstream of the orifice plate flowmeter (100 ± 5) mm, the exhaust pipe axis position.
⑧Exhaust pipe: made of stainless steel, pipe diameter of 114mm, length of about: 1500mm, equipped with fans, flow meters, sensors and so on. Ensure that the equipment has a good ventilation system, after the completion of the test, the combustion products can be discharged from the combustion chamber to the atmosphere. Ventilation performance is adjusted according to the test requirements, and the airflow rate should be limited to a certain range to ensure the accuracy of the test results.

Collection, measurement systems

5.Sample gas collection and pre-treatment device:
①The sample gas collection and pretreatment device consists of a ring sampler, filtration system, suction pump, condenser and other components;
②Ring sampler ring sampler installed in the exhaust pipe and concentric with the pipe, with a homogenising airflow device;
③Three-stage filtration, with high temperature resistance, acid and alkali corrosion and oxidation resistance, a filter precision of not less than 0.45 ~ 50um;
④Filter cartridge installation using easy to install and dismantle structure; secondary filtration device with drainage function of the air protection filter, reliable separation of solids contained in the gas, filtration accuracy of not less than 0.2um-20um; tertiary filtration device for filtering water in the sample gas after cooling. The filter cylinder is easy to disassemble and replace the filter medium;
⑤Adopting vacuum pump to extract sample gas, the vacuum pump has low noise and small vibration, the pumping flow rate is 36L/min, and the maximum outlet pressure is 7KG;
⑥Equipped with compression refrigeration condenser: dew point temperature of 0 ~ 5 ℃;
⑦Equipped with imported German KNF diaphragm pump, flow rate of 33 L/min, vacuum: 700 mmHg, pressure: 2.5 bar;
⑧Sample gas pipeline equipped with self-cleaning system, after the completion of the experiment can be set to reverse blowing clean sample gas pipeline.

6.Calibration of the burner and its gas supply system:
①Equipped with brass tubes, etc. as the calibration burner, the burner adopts the fibre filling and filter device to expand the combustible gas and burn evenly.
②Calibration burner gas supply system for regulators, pressure gauges, MFC, etc., to determine can provide a stable source of gas for combustion. MFC range of 10L/min, accuracy of ± 1% F.S., linear ± 0.5% F.S., response time ≤ 2sec.
③The calibration burner can be suspended and mounted under the radiation cone by means of a clip type fixture, which requires easy operation and accurate positioning.
④In order to calibrate the response of the whole test system, a brass tube with a square opening and a square cross-section is used as the calibration burner. The burner: a hole with an area of (500±100)mm² is cut into the metal in the shape of a garden, the opening is covered with a wire mesh in order to diffuse the gas, and the tube is filled with ceramic fibres in order to increase the homogeneity of the gas flow.

①Oxygen (O2) analyser: Germany (Siemens) SIEMENS, paramagnetic type.

a.Measuring range: (0-25)%.

b.Signal output: 4-20mA;

c.Resolution 100×10-6

d.Relative humidity: <90% (no condensation)

e.Linearity deviation: <±0.1% O2;

f.Zero drift: ≤0.5%/month;

g.Range drift: ≤0.5%/month

h.Internal signal processing time less than 1S;

j.Response time: T90 <5 seconds

k.Repeatability: <±0.02% O2;

l.Local display: LCD liquid crystal display (with backlight)

m.Analogue output: 4～20mA 750Ω

n.Ambient temperature: 5 ℃ ~ +45 ℃; power supply: 220VAC ± 10%, 50 ~ 60Hz.

o.The noise drift of the analyser within 30min is not more than 0.01%; the resolution of the data acquisition output is better than 0.01%6;

7.Carbon dioxide (CO2) analyser: origin is Germany AGM Sensors non-discriminating infrared (NDIR) sensor module:

1) Measurement principle: non-discriminating infrared NDIR, dual-wavelength, single beam.

2)Measuring range:0-10%;

3)Response time: ≤6s.

4)Accuracy: full scale ±2% FS

5) Stability: full scale ±2% FS ( more than 12 months)

6) Repeatability: ±0.2% (at zero point), 1% (at sample gas)

7)Minimum detection value: <1% FS of full scale

8)Linearity Error: <2%FS of full scale

9)Status/fault control: two-colour LED display

10)Status/fault output: +5V HCMOS on 34-Pin connector

11) Analogue output: 4～20mA 750Ω

12)Ambient temperature:5℃～＋45℃

(13) Power supply: 220VAC ± 10%, 50 ~ 60Hz 5000W

(14) 30min analyzer noise drift are not more than 100 × 10-6

8.arbon monoxide CO analyser: origin of Germany AGM Sensors non-discriminating infrared (NDIR) sensor module: (optional)

1) Measuring range: 0～1%;

2) Response time: ﹤6s

3) Repeatability: 0.1 ppm

4) Zero drift: ≤2%/week

5) Range drift: ≤2%/week

6) Linear deviation: ＜±1%

9.Analyser into the gas flow rate of 3.5L/min, the gas circuit is equipped with a flowmeter to prevent overload on the analyser damage; flowmeter range of 0.5 ~ 5L/min; equipped with a diversion device dispersed to empty the excess gas.

10.The calibration interface is reserved for calibrating the gas analyser gas sensors.

11.Smoke density measurement system:

smoke density measurement system is located in the exhaust pipe near the end of the exhaust fan, by the light source launching device, correction mechanism, temperature measurement device, etc., measurement process due to the accumulation of smoke dust, the light transmittance should not be reduced by more than 5%.

13.Light source:

the light source emitting device is a helium-neon laser, which can produce a red light source with spectral wavelength of 632.8 nm and random polarisation for smoke concentration testing; the linearity of the controller at the receiving end of the light source is ≥99.8%, and the instability is <0.1%;

The light source channel is designed with a calibration mechanism, which can correct 100% and 0% of the light source reception; a thermocouple is installed on one side of the light element to measure the temperature of the smoke, and provide signals to the main control program to participate in the calculation of experimental result data.

14.Lens:

Convex lens of 50mm diameter and 60mm focal length, so that the parallel beam through the smoke exhaust pipe is 30mm in diameter.

15.Photoelectric receiving element:

Japan Hamamatsu monocrystalline silicon photoelectric element is used to determine the smoke density through the change of the intensity of the light beam received, and the accuracy of the measurement of the light intensity shall not be less than ±5%.

16.The accuracy of the chromaticity standard function of the optical system detector shall not be less than ±5%, and the output linearity is within 5%;

17.Optical smoke density meter is installed in the position of uniform distribution of smoke in the exhaust pipe, the light beam can pass through the exhaust pipe vertically, the installation of the optical smoke density meter does not affect the speed measurement and sampling, the glass window of the optical smoke density meter is made of quart

18.Control system:
①Computer control interface mode: the use of computer + professional software control, guided operation, easy to operate safe and reliable, all the cumbersome procedures and operations have been integrated into the computer, the response speed is very fast, easy to operate, user-friendly interface, foolproof operation.
②The software adopts LabeView, a special development software for instruments and equipment, and data acquisition control card; it can view the test data in real time during the control test, and realise automatic data calculation, acquisition and processing, data saving and outputting of experimental reports and measurement results; it has the features of high intelligence, guided menu operation, simplicity and intuitive operation, which makes the test results more accurate.
③Built-in equipment pre-calibration and work calibration procedures, can be convenient for weighing equipment accuracy, radiation cone under different radiation illumination cone temperature, zero correction of the optical circuit, the analyser of each sensor accuracy calibration;
④Individual sensor calibration modes can be set up, including single or double point calibration of the oxygen analyser, carbon dioxide analyser, carbon monoxide analyser, differential micro-pressure transducer, smoke density measurement system, weighing device, mass flow control, to obtain the best linearity;
⑤C-parameter calibration: C-factor deviation of two calibrations is not more than 5%, and the equipment operates stably after calibration, which ensures the real and reliable measurement results.
⑥Status checking interface, which can obtain the working status of each sensor component of the instrument at a glance; it can record the working values of each sensor, including differential micro-pressure sensor, chimney temperature, oxygen analyser, carbon dioxide analyser, and carbon monoxide analyser; the report template is in EXCELL format, which can display the graphic and numerical value modes.
⑦can directly measure the material properties including heat release rate, ignition time, ignition heat, mass loss rate, smoke release rate, the effective heat of combustion, CO2, CO generation, etc.; test data output, can be saved and printed; with powerful features, especially can be compared with multiple curves, you can intuitively compare the difference between the combustion characteristics of the material.
⑧Acquisition system can collect and record oxygen concentration, temperature, heat release rate, orifice plate flowmeter, thermocouples, hot flue gas flow rate, specimen ignition time and extinguishing time, total oxygen consumption, mass loss rate, total heat release, carbon dioxide generation and carbon monoxide generation curves, all the process of quantitative curves and real-time data. It can be saved and printed.
⑨Ignition system: high-voltage spark generator with safety cut-off device, high-voltage automatic ignition, automatic positioning, the sample in the combustion platform by the igniter ignition, ignition speed is rapid, can ensure the accuracy of the test results.

Software Operate Page