Fire resistance testing method and device

Abstract

The invention discloses a fire resistance testing method and device, and the method comprises the steps: carrying out the continuous heating of a horizontal liquid level of a certain mass of liquid material through open fire, recording the temperature of the liquid level of the liquid material or the change of the temperature of liquid adjacent to the liquid level along with the time until the liquid material is ignited, and carrying out the heating through the open fire until the time needed by the ignition of the liquid material, the fire resistance of the liquid material is represented according to the difference value between the liquid level temperature when the liquid material is ignited or the liquid temperature adjacent to the liquid level and the liquid level temperature when open fire heating is started or the liquid temperature adjacent to the liquid level, the method is simple and rapid, and testing is convenient.

Description

Technical Field

[0001] The invention relates to a fire resistance testing method and a device. Technical Background

[0002] In recent years, with the popularity of new energy pure electric vehicles and the increase in the number of electric vehicles, accidents of electric vehicle fires and spontaneous combustion have also occurred from time to time. If new energy vehicles are to continue to develop, the problems of safety and reliability must be solved. The current research on thermal management of power batteries includes the use of the large heat capacity of coolant and the ability to take away excess heat from the battery system through circulation to achieve the optimal operating temperature conditions of the battery pack, among which the fire resistance test of coolant is one of the key links. At present, the market basically has fire resistance test methods for solid materials, and there are no fire resistance test methods for liquid materials. Traditional fire resistance test methods require the modification of instruments to detect the fire resistance of coolants. For example, cone calorimeters require customized special containers to detect liquids. Not only are the equipment expensive, but the test time is long and the operation is complicated. At the same time, it is impossible to analyze the fire resistance of coolants under the state of simulating thermal runaway of new energy vehicle batteries. Summary of the invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to disclose a fire resistance testing method and device. The fire resistance testing method can simulate the fire resistance performance of liquid materials under the action of open flames in actual scenarios. The equipment cost is low, and the fire resistance of liquid materials such as coolants can be easily and quickly evaluated, providing data support for battery thermal runaway protection design.

[0004] The technical solution provided by the present invention is as follows:

[0005] A fire resistance test method includes continuously heating the horizontal liquid surface of a liquid material with an open flame, and recording the change of the liquid surface temperature T or the liquid temperature T adjacent to the liquid surface with time t until the liquid material is ignited, and using the time (tx) required from the start of open flame heating (t0) to the ignition of the liquid material (tm), and the difference (Tx) between the liquid surface temperature (Tm) or the liquid temperature adjacent to the liquid surface (Tm) when the liquid material is ignited and the liquid surface temperature (T0) or the liquid temperature adjacent to the liquid surface (T0) when the open flame heating is started to characterize the fire resistance of the liquid material, wherein tx = tm-t0, Tx = Tm-T0. In the test method, the larger the tx and Tx values, the better the fire resistance of the liquid material.

[0006] The liquid material includes a homogeneous liquid material that can flow by itself to form a uniform liquid surface. Specifically, its flash point > 100°C to ensure no obvious volatilization or premature spontaneous combustion during the open-flame heating process. At the same time, no chemical reaction or other changes occur during the open-flame heating process to cause a change in the properties of the liquid material, including but not limited to coolants for energy storage systems (such as battery systems for electric vehicles and energy storage battery systems), coolants for industrial electronic products (such as server rooms, transformers), and other liquid materials that require evaluation of fire resistance performance.

[0007] The method of open-flame heating adopts the prior art, including a spray gun, a gas lamp, etc. It is only necessary to keep the flame in continuous contact with the horizontal liquid surface of the liquid material and remain stable, simulating the heat-receiving and combustion process of liquid materials such as coolants in the open-flame state in practice.

[0008] The ignition of the liquid material described in the present invention means that a flame appears on the surface of the liquid material, which can be determined by observation or by means of photography or taking pictures to improve the accuracy.

[0009] The device for performing the fire resistance test using the fire resistance test method at least includes an upper-open container (2) for containing the liquid material (1), a heating device (3) for continuously heating the horizontal liquid surface of the liquid material (1), a temperature measuring device (4), and a timing device (5).

[0010] The liquid material (1) includes a homogeneous liquid material that can flow by itself to form a uniform liquid surface. Specifically, its flash point > 100°C to ensure no obvious volatilization or premature spontaneous combustion during the open-flame heating process. At the same time, no chemical reaction or other changes occur during the open-flame heating process to cause a change in the properties, including but not limited to coolants for energy storage systems (such as battery systems for electric vehicles and energy storage battery systems), coolants for industrial electronic products (such as server rooms, transformers), and other liquid materials that require evaluation of fire resistance performance.

[0011] The dosage of the liquid material (1) is adjusted according to the capacity of the upper-open container and the test requirements. The basic requirement is to actually observe the flame when the liquid material starts to burn (is ignited), that is, to facilitate observing and determining the time point when the liquid material starts to burn (is ignited). Excessive dosage of the liquid material results in a long heating time, causing waste of materials and energy, while too little dosage of the liquid material leads to too short a heating time and easily causes large test errors. In specific embodiments, an appropriate dosage of the liquid material can be selected according to the situation and kept consistent in multiple sample tests, so as to compare their fire resistance performance.

[0012] Preferably, the upper-open container (2) is cylindrical or cuboid-shaped. The upper-open setting allows for a wider liquid surface, facilitating the heating operation. The specific dimensions of the upper-open container (2) include that there is no special limitation on the depth, enabling the open-flame heating and combustion process to be in an open space and reducing test errors caused by air flow, etc.

[0013] The material of the upper-open container (2) is a common material, such as iron, copper, etc., or has a heat-insulating layer, without special restrictions. Preferably, a material with a low heat transfer rate is used to reduce heat loss and the resulting data fluctuations.

[0014] Preferably, the upper-open container (2) has a viewing window to facilitate observing and determining the time point when the liquid material starts to burn (is ignited), or recording the time point when the liquid material starts to burn (is ignited) by means of photography.

[0015] Preferably, the upper-open container (2) has a scale for measuring the depth of the liquid material (1) and a component for weighing the sum of the masses of the liquid material (1) and the upper-open container (2), so as to ensure the consistency of the mass during multiple tests of the liquid material sample, and adjust the position and angle of the flame-spraying component (3-1) in the heating device (3) to ensure the consistency of the position and angle during multiple tests.

[0016] Preferably, the upper-open container (2) has a discharge port with a valve, and its position is at the bottom or on the side wall near the bottom, so as to facilitate discharging the unburned liquid material (1) and cleaning the upper-open container (2).

[0017] The timing device (5) starts timing when the flame-spraying component (3-1) (such as a spray gun) of the heating device (3) starts to spray flame for heating, and stops heating the device (3) and ends timing until the liquid material (1) is ignited. The heating device (3) for continuously heating the horizontal liquid surface of the liquid material (1) can be an existing one, at least including a flame-spraying component (3-1) (such as a spray gun), a connecting component (3-2) (such as a hose), and a fuel storage component 3-3 (such as a high-pressure gas storage tank), which is a device capable of spraying a long-distance controllable flame, and the fuels used include high-pressure propane or natural gas. The flame sprayed by the flame-spraying component (3-1) should have good stability, including flame temperature, length, etc., to improve the accuracy of the fire resistance test results of the liquid material (1).

[0018] The angle at which the flame-spraying component (3-1) of the heating device (3) sprays the flame is preferably 60° with respect to the liquid surface of the liquid material (1). The position of the center of the nozzle orifice of the flame-spraying component (3-1) relative to the liquid surface of the liquid material (1) is required to ensure that the tip of the flame is in complete contact with the liquid surface of the liquid material (1), so as to simulate the fire resistance performance of the liquid material (1) under the actual open flame burning state. In actual operation, when testing different samples, for liquid material samples of the same mass, the relative height and position of the center of the nozzle orifice of the flame-spraying component (3-1) of the heating device (3) with respect to the liquid surface of the liquid material (1) should be kept consistent to ensure a consistent open flame heating state for the liquid material (1) and improve the accuracy and repeatability of the test.

[0019] Preferably, the position where the flame sprayed by the flame-spraying component (3-1) of the heating device (3) for continuously heating the horizontal liquid surface of the liquid material (1) is in complete contact with the liquid material (1) is the center of the liquid surface of the liquid material (1), or a contact surface centered on the center of the liquid surface of the liquid material (1). The size of the contact surface should meet the basic requirement that the flame does not overflow severely, and the contact surface should be kept consistent during multiple tests to improve the repeatability and comparability of the data.

[0020] The temperature measuring device (4) can be an existing one, used to measure the liquid surface temperature of the liquid material (1) or the liquid temperature near the liquid surface, including a thermistor temperature detector, a thermocouple temperature sensor, an infrared temperature detector, etc. For the infrared temperature detector, the temperature detection point is preferably at the liquid surface position outside the contact surface between the flame sprayed by the heating device (3) and the liquid material (1). For contact temperature detectors such as thermistor temperature detectors and thermocouple temperature sensors, the temperature detection point is at a position as close to the liquid surface as possible below the liquid surface. In specific embodiments, the liquid position close to the center point of the liquid surface can be selected as the temperature detection point according to the stability of the temperature test results, and the temperature detection point should be fixed to improve the accuracy and repeatability of the test results for multiple times and multiple samples.

[0021] Preferably, the temperature measuring device (4) is connected with a data recording and output device to facilitate accurate recording and output of the temperature of the liquid material (1) and the corresponding time during the test process.

[0022] Preferably, the timing device (5) can be connected to the temperature measuring device (4) or can be independent. Timing starts when the heating device (3) starts spraying the flame for heating and ends when the liquid material (1) is ignited.

[0023] Preferably, the device for performing the fire resistance test using the fire resistance test method of the present invention further includes a frame or a combustion chamber for fixing the upper open container (2), the flame spraying component (3-1) of the heating device (3), and the temperature measuring device (4). Preferably, the frame or the combustion chamber is semi-enclosed, and the process of the flame spraying component (3-1) in the heating device (3) releasing a flame to conduct open-flame burning on the liquid surface of the liquid material (1) should be in an open space to ensure the combustion conditions and that the controlled combustion conditions are the same.

[0024] In the frame or the combustion chamber, the fixing methods of the upper open container (2), the flame spraying component (3-1) of the heating device (3), and the temperature measuring device (4) are existing ones. For example, the upper open container (2) is fixed to the bottom of the frame or the combustion chamber by a detachable fixing method such as threaded connection. The flame spraying component (3-1) of the heating device (3) is fixed to a vertical fixing rod by a slidable component and can be moved up and down on the fixing rod manually or pneumatically, so as to adjust the position of the flame spraying component (3-1) and keep the position of the flame spraying component (3-1) relative to the liquid surface of the liquid material (1) unchanged. The temperature measuring device (4) is fixed to the top of the frame or the combustion chamber by means such as a buckle to keep the temperature measuring point unchanged, improving the accuracy and repeatability of the test.

[0025] Preferably, the device further includes a thermostat for adjusting the temperature of the liquid material (1) in the upper open container (2) to adjust and maintain the temperature of the liquid material (1) uniformly before the test starts, improving the comparability of multiple test data.

[0026] Preferably, the device for performing the fire resistance test using the fire resistance test method of the present invention is installed in a non-airtight but air-still space, maintaining the air temperature at 25°C.

[0027] The advantages of the present invention compared with the prior art are:

[0028] The test method and device of the present invention can simply and quickly test the fire resistance performance of liquid materials, and can be flexibly adjusted according to the characteristics of the materials, with good adaptability and a good application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the fire resistance test device of the present invention: 1 - liquid material, 2 - upper open container, 3 - portable flame gun, 4 - infrared thermometer, 5 - timer.

[0030] Figure 2 Schematic diagram of the temperature measuring point and the flame contact point in the fire resistance test device: 3-1 flame spraying component, 3-2 connecting piece, 3-3 fuel storage component, 1 - liquid material, 2 - upper open container, 4 - infrared thermometer, 7 - flame contact point, 8 - temperature measuring point. Detailed implementation manners

[0031] The following provides specific embodiments to further illustrate the present invention.

[0032] Embodiment

[0033] The fire resistance testing device of the present invention is as Figure 1 shown, including an upper-opening container 2 for containing a liquid material 1 (in a cylindrical shape, with the barrel wall and barrel bottom made of iron, an outer diameter of 16 cm, a height of 16 cm, and a wall thickness of 0.5 cm), wherein the mass of the liquid material 1 is 1 kg, a portable flame gun 3 for continuously heating the horizontal liquid surface of the liquid material 1 with an open flame (manufactured by Jinshilu, model 231 metal type, with a maximum flame temperature of 1300 °C, a flame length of 10 - 20 cm, and 3 gears, including a flame spraying part 3-1, a connecting part 3-2, and a fuel storage part 3-3), as well as an infrared thermometer 4 and a timer 5. The schematic diagrams of the temperature measurement points and the flame contact points in the device are as Figure 2 shown, wherein the angle between the flame sprayed by the flame spraying part 3-1 of the portable flame gun 3 and the horizontal liquid surface of the liquid material 1 is 60°, the vertical distance between the center of the nozzle opening of the flame spraying part 3-1 and the horizontal liquid surface of the liquid material 1 is 10 cm, the position 7 where the flame sprayed by the flame spraying part 3-1 contacts the horizontal liquid surface of the liquid material 1 is as Figure 2 shown, the distance between the temperature measurement point 8 of the infrared thermometer 4 and the center of the liquid surface is 5 cm, and the position of the temperature measurement point 8 is as Figure 2 shown.

[0034] The fire resistance performance testing process is as follows: Pour the liquid material 1 into the upper-opening container 2. After standing to form a stable liquid surface, turn on the 3rd gear switch of the portable flame gun 3 and ignite it, so that the flame spraying part 3-1 sprays out a flame to continuously heat the horizontal liquid surface of the liquid material 1 with an open flame. At the same time, start timing t0 and record the initial liquid surface temperature T. Until it is observed that the liquid material 1 is ignited, turn off the portable flame gun 3 to stop heating with an open flame, record the ignition time tm, and the temperature Tm at the time of ignition, and calculate tx = tm - t0, Tx = Tm - T0. Use the values of tx and Tx to characterize the fire resistance performance of the liquid material.

[0035] In the same space at 25 °C and without wind, use the said device and method to respectively conduct fire resistance tests on the 1# lithium-ion battery coolant (model AP-5, Shenzhen Anpin Organosilicon Materials Co., Ltd., liquid surface height of 5.96 cm) and the 2# lithium-ion battery coolant (model 8005, Fuchs, liquid surface height of 6.9 cm). Each sample is tested in parallel 6 times, and the data is shown in Table 1.

[0036] Table 1 Test data of the 1# lithium-ion battery coolant

[0037] 1 2 3 4 5 6 Mean value T0 / ℃ 11 11 11 11 11 10 11 Tm / °C 300 306 303 305 304 306 304 tx / s 374 378 371 372 379 366 373

[0038] Table 2 Test Data of Coolant for 2# Lithium-Ion Battery

[0039] 1 2 3 4 5 6 Mean value T0 / ℃ 11 11 11 10 11 10 11 Tm / °C 211 215 209 210 213 214 212 tx / s 237 231 234 229 232 233 233

[0040] It can be seen from the data in Table 1 and Table 2 that the test method of the present invention can quickly judge the fire resistance of liquid materials. Under the same test conditions, the higher the ignition temperature and the longer the ignition time, the better the fire resistance, and the test data has good repeatability.

[0041] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should all be regarded as belonging to the protection scope of the present invention.

Claims

1. A refractory test method includes continuously heating the horizontal liquid surface of a liquid material of a certain mass with an open flame, while recording the change of the liquid surface temperature T of the liquid material or the liquid temperature T adjacent to the liquid surface with time t until the liquid material is ignited. The refractory performance of the liquid material is characterized by the time tx required from the start of open flame heating to the ignition of the liquid material, and the difference Tx between the liquid surface temperature Tm or the liquid temperature Tm adjacent to the liquid surface when the liquid material is ignited and the liquid surface temperature T0 or the liquid temperature T0 adjacent to the liquid surface at the start of open flame heating, where Tx = Tm - T0.

2. The refractory test method according to claim 1, characterized in that, The liquid material is a homogeneous liquid material that can flow by itself to form a uniform liquid surface, with a flash point > 100 °C, and no chemical reactions or other changes occur during the open flame heating process that cause changes in the properties of the liquid material.

3. A device for refractory testing using the refractory test method according to claim 1, at least including an upper-opening container (2) for containing the liquid material 1, a heating device (3) for continuously heating the horizontal liquid surface of the liquid material (1) with an open flame, and a temperature measuring device (4) and a timing device (5).

4. The device according to claim 3, characterized in that, The upper-opening container (2) is cylindrical or cuboid-shaped.

5. The device according to claim 3, characterized in that, The upper-opening container (2) has a window for observing or recording the time point when the liquid material (1) is ignited by means of photography or taking pictures.

6. The device according to claim 3, characterized in that, The upper-opening container (2) is provided with a scale for measuring the depth of the liquid material (1).

7. The device according to claim 3, characterized in that, The device includes a component for weighing the sum of the mass of the liquid material (1) and the upper-opening container (2).

8. The device according to any one of claims 3-7, characterized in that The heating device (3) for continuously heating the horizontal liquid surface of the liquid material (1) at least includes a flame-spraying component (3-1), a connecting component (3-2), and a fuel storage component (3-3). The position of the center of the nozzle opening of the flame-spraying component (3-1) relative to the horizontal liquid surface of the liquid material (1) is basically required to make the top of the flame fully contact with the liquid surface of the liquid material (1).

9. The device according to any one of claims 3-7, characterized in that The temperature measuring device (4) is a thermistor temperature detector, a thermocouple temperature sensor, or an infrared temperature detector.

10. The device according to claim 8, characterized in that, The device also includes a frame or a combustion chamber for fixing the upper-opening container (2) and the flame-spraying component (3-1) in the heating device (3) to keep the position of the center of the nozzle opening of the flame-spraying component (3-1) relative to the liquid surface of the liquid material (1) unchanged.

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