Device and method for testing ignition risk of dust in curved-surface heat dissipation fins

Abstract

The invention discloses a device for testing the ignition risk of dust in a curved-surface heat dissipation fin, and the device comprises a horizontally disposed pedestal which is provided with a detachable curved-surface heat dissipation fin testing assembly. The curved-surface heat dissipation fin test assembly comprises a curved-surface powder carrying table, a heating device laid on the upper surface of the curved-surface powder carrying table and heat dissipation fins arranged on the heating device in parallel. The invention further discloses a method for testing the ignition risk of the dust in the curved-surface heat dissipation fins, dust layers with different dust heights are stacked in the curved-surface heat dissipation fin testing assemblies with different fin distances, and the corresponding lowest ignition temperature is obtained through testing. According to the method, the blank of an existing method for testing the ignition risk of the layered accumulated dust in the curved-surface heat dissipation fin is effectively filled, and targeted testing can be carried out according to the actual working condition characteristics that the heated surface of the dust in the curved-surface heat dissipation fin is larger, and the heating time is longer.

Description

Technical Field

[0001] This invention belongs to the field of industrial dust explosion protection technology, and particularly relates to a testing device for the fire hazard of dust inside curved heat sink fins, and a testing method for the fire hazard of dust inside curved heat sink fins. Background Technology

[0002] In combustible powder process industries, the ignition of accumulated dust is a common ignition source for dust explosions. To assess the ignition risk of combustible dust accumulation on hot surfaces, a complete set of minimum ignition temperature testing standards for dust layers has been promulgated both domestically and internationally, such as GB / T 16430, "Method for Determination of Minimum Ignition Temperature of Dust Layers." Based on these standards, corresponding minimum ignition temperature testing devices for dust layers have also emerged.

[0003] However, in actual industrial production, combustible dust not only accumulates on the ideal flat heat sink as required by standards, but also commonly accumulates within curved heat sink fins. Existing research indicates that compared to the single-sided heating of flat plates, combustible dust accumulated within curved heat sink fins has a larger heated surface area. Because the dust is difficult to clean, it is heated for a longer period. Furthermore, in actual operating conditions, curved heat sink fins of varying specifications exist. When the width and height of the curved heat sink fins change, the risk of dust accumulation, ignition, and subsequent explosion may be even higher.

[0004] However, there are currently no relevant testing standards for testing and evaluating the fire risk of dust accumulation inside curved heat sink fins, nor are there any testing devices based on these standards. Existing dust layer fire sensitivity testing standards are all for testing the dust fire sensitivity under the action of planar hot surfaces.

[0005] Therefore, there is an urgent need to design a new testing device and method for the ignition sensitivity of dust accumulated inside curved heat sink fins. It should meet the requirements for testing the ignition sensitivity of dust accumulated under the heating condition of curved heat sink fins, so as to improve the existing evaluation index system for the ignition sensitivity of combustible dust and fill the gap in the existing standards for testing the ignition sensitivity of combustible dust. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a testing device for the fire hazard of dust inside curved heat sink fins, and also provides a testing method for the fire hazard of dust inside curved heat sink fins. This effectively satisfies the fire hazard testing requirements for layered dust accumulation inside curved heat sink fins, effectively improves the existing evaluation index system for the fire hazard of combustible dust inside curved heat sink fins, and fills the gap in existing testing methods for the fire hazard of layered dust accumulation inside curved heat sink fins.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A testing device for the fire hazard of dust inside curved heat sink fins includes a base, which is placed horizontally. A detachable curved heat sink fin testing assembly is installed on the base. The curved heat sink fin testing assembly includes a curved powder carrier platform placed on the base. The two sides of the curved powder carrier platform are located on the same horizontal plane. A heating device is laid on the upper surface of the curved powder carrier platform. Multiple heat sink fins are installed on the heating device. The heat sink fins are arranged in parallel with equal spacing. Dust from the dust layer to be tested falls into the gaps between the heat sink fins. A temperature testing device is inserted into the dust layer and connected to an external computer. The heating device is electrically connected to the temperature heating generator in sequence through the first wire and the conductive connector.

[0008] As mentioned above, both the base and the curved powder-carrying platform are made of insulating materials; the scraper is made of metal.

[0009] The testing device for the fire hazard of dust inside curved heat sink fins, as described above, also includes a high-speed camera and an infrared thermal imager, with the image acquisition lenses of the high-speed camera and the infrared thermal imager aimed at the dust layer.

[0010] A method for testing the fire hazard of dust inside curved heat sink fins, utilizing any of the aforementioned testing devices for the fire hazard of dust inside curved heat sink fins, includes the following steps: Step 1: Place the base horizontally; Step 2: Under the test conditions of dust layer accumulation of different heights in curved heat sink fin test components with different fin spacing, the following operations were performed respectively: Step 2.1: Install the curved heat sink test assembly on the base so that both sides of the curved powder carrier stage are at the same horizontal height, and the heat sink fins are always perpendicular to the horizontal plane. Step 2.2: The heating device is connected to the temperature heating generator in sequence through the first wire and the conductive connector; the temperature testing device is connected to an external computer through the second wire. Step 2.3: Start the temperature heating generator and temperature testing device; Step 2.4: Pour the dust to be tested into the curved heat sink test component and test the lowest ignition temperature of the corresponding dust layer; Step 2.5: Stop the temperature heating generator and temperature testing device.

[0011] As described above, step 2.4 specifically includes the following steps: Step 2.4.1: Control the temperature generator to make the temperature of the heating device equal to the preset initial temperature; Step 2.4.2: Slowly pour the dust to be tested into the curved powder carrier stage so that the dust falls into the gap between the heat sink fins. Use a scraper to smooth the upper surface of the dust layer, and then clean up the dust scattered around the curved powder carrier stage. Step 2.4.3: Maintain a constant temperature for the heating device and continuously monitor the state of the dust layer in real time. a) When a dust layer is observed to be on fire: If it is the first round of observation, or if it is not the first round of observation and the dust layer also caught fire in the previous round of observation, then lower the temperature of the temperature generator, remove the dust layer on the curved powder carrier stage, replace the dust to be tested at room temperature, and return to step 2.4.2. If this is not the first round of observation and the dust layer did not ignite in the previous round of observation, then the control temperature of the temperature heating generator is the minimum ignition temperature at this time; b) If no dust layer ignition is observed within 30 minutes or longer, and the control temperature displayed by the temperature generator does not reach 400°C: If it is the first round of observation, or if it is not the first round of observation and the dust layer did not ignite in the previous round of observation, then increase the control temperature of the temperature generator to raise the temperature of the heating device, remove the dust layer in the curved powder carrier stage, replace the dust to be tested at room temperature, and return to step 2.4.2. If it is not the first round of observation and the dust layer was on fire in the previous round of observation, then the control temperature of the heating generator corresponding to the temperature in the previous round of observation is the minimum ignition temperature; c) When the temperature control temperature of the temperature heating generator reaches 400℃ and the dust layer does not ignite for 30 minutes or longer, it indicates that the dust layer is not easy to ignite under the test conditions.

[0012] If any of the following conditions are observed, it can be determined that the dust layer is on fire as described above: The dust layer was observed to be burning with or without flame using a high-speed camera and an infrared thermal imager. The temperature of the dust layer was observed by the temperature testing device to be 250°C higher than the control temperature of the temperature heating generator. The temperature of the dust layer was observed to reach 450℃ using a temperature testing device.

[0013] As described above, in step 2.4, steps 2.4.1 to 2.4.3 are repeated at least three times. The average value of the lowest ignition temperature obtained from the repeated tests is taken as the final lowest ignition temperature under the corresponding test conditions.

[0014] As described in step 2.4.3 above, the difference between the controlled temperature of the temperature heating generator and the temperature before and after the temperature increases or decreases is less than 10℃.

[0015] The dust height of the dust layer described above under different test conditions was controlled in the following manner: For each test condition, the fin height of the heat dissipation fins in the selected curved heat dissipation fin test assembly is equal to the required dust height. In step 2.4.2, the scraper flattens the upper surface of the dust layer and makes the dust height of the dust layer flush with the fin height of the heat dissipation fins.

[0016] The dust height of the dust layer described above under different test conditions was controlled in the following manner: In the curved heat dissipation fin test assembly, the fin height of the heat dissipation fins is higher than the dust height required under all test conditions. The corresponding scraper includes a comb-shaped brush, and the width of the teeth corresponds to the fin spacing under the corresponding test conditions. In step 2.4.2, the scraper flattens the upper surface of the dust layer and makes the dust height of the dust layer equal to the dust height required under the corresponding test conditions.

[0017] Compared with the prior art, the present invention has the following advantages: This invention effectively fills the gap in existing testing methods for the fire hazard of layered dust accumulation within curved heat sink fins, and overcomes the limitation of existing dust layer fire sensitivity testing standards that only address dust testing under planar hot surfaces. It also improves the evaluation index system for the fire sensitivity of combustible dust. It effectively meets the testing needs for the fire hazard of layered dust accumulation under curved heat sink fin heating conditions, and can conduct targeted tests based on the actual operating conditions, such as the larger heated surface area and longer heating time of dust within curved heat sink fins. Simultaneously, the temperature generator can precisely control the temperature at the bottom of the heat sink fins, and in conjunction with the temperature testing device, it can accurately monitor the dust layer temperature, providing reliable data for assessing fire hazard. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a testing device for the fire hazard of dust inside curved heat sink fins according to the present invention; Figure 1 In the middle, 1—base, 2—curved powder carrier, 3—heat dissipation fins, 4—heating device, 5—temperature heating generator, 6—scraper, 7—temperature testing device, 8—conductive connector, 9—first wire, 10—scale, 11—dust layer, 12—second wire. Detailed Implementation

[0019] To facilitate understanding and implementation of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to embodiments. The embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] Example 1: like Figure 1 As shown, a testing device for the fire hazard of dust inside curved heat sink fins is used to obtain the lowest ignition temperature of the dust layer. The specific structure is as follows: The device includes a base 1, a curved powder carrier platform 2, heat dissipation fins 3, a heating device 4, and a temperature generator 5. A detachable curved powder carrier platform test assembly is set on the horizontally placed base 1. The curved powder carrier platform test assembly includes the curved powder carrier platform 2 placed on the base 1, as well as the heating device 4 and the heat dissipation fins 3. The curved powder carrier platform 2 is always in a horizontal state (i.e., both sides of the curved powder carrier platform 2 are located on the same horizontal plane). The heating device 4 is laid on the upper surface of the curved powder carrier platform 2, and multiple heat dissipation fins 3 are set on the heating device 4. In this embodiment, the heating device 4 is directly used as the hot surface, and the temperature of the heating device 4 is used as the hot surface temperature, so that the hot surface temperature obtained by the present invention is more accurate than that of the prior art (which sets the heating device below the curved powder carrier platform 2). In this embodiment, to study the influence of the spacing between the heat dissipation fins 3 (denoted as fin spacing) and the height of the accumulated dust on dust ignition, a test assembly containing curved heat dissipation fins of different specifications (such as heat dissipation fins 3 with different fin heights and fin spacings) can be selected. The heat dissipation fins 3 are arranged in parallel with equal spacing, so that the dust of the dust layer 11 to be tested falls into the gaps between the heat dissipation fins 3. The dust on the heat dissipation fins 3 is scraped flat by the scraper 6, so that the surface of the dust layer 11 is at the same level. A temperature testing device 7 is inserted into the dust layer 11 laid on the curved dust carrier platform 2. The temperature testing device 7 is connected to an external computer through the second wire 12, and the temperature of the dust layer 11 is tested by the temperature testing device 7. The heating device 4 is electrically connected to the temperature heating generator 5 through the first wire 9 and the conductive connector 8 in sequence. The temperature of the heating device 4 located at the bottom of the heat dissipation fins 3 is controlled by the temperature heating generator 5.

[0021] The fin height is equal to the height difference between the top horizontal plane of the heat dissipation fin 3 installed on the heating device 4 and the lowest horizontal plane of the upper surface of the heating device 4 (i.e., the minimum value of the bottom horizontal plane height of all heat dissipation fins 3).

[0022] By selecting curved heat dissipation fin test components with different fin heights and fin spacings, the actual working conditions of heat dissipation fins of different specifications are simulated, which meets the testing requirements for the risk of dust accumulation and fire under different gaps and heights, and provides a reliable variable adjustment method for studying the influence of fin structure on dust fire risk.

[0023] The base 1, the curved powder carrier platform 2, and the heat dissipation fins 3 are all made of insulating materials; the scraper 6 is made of metal materials to prevent the dust layer 11 from being ignited by static electricity generated by friction or by human static electricity during the preparation process.

[0024] Furthermore, to prevent high-voltage electric shock, both the first conductor 9 and the second conductor 12 are covered with high-voltage insulating protective sleeves.

[0025] Furthermore, in order to better record the ignition process and temperature distribution of the dust layer 11 inside the heat dissipation fins 3, the test device for the ignition hazard of dust inside the curved heat dissipation fins is also equipped with a high-speed camera and an infrared thermal imager, with the image acquisition lenses of the high-speed camera and the infrared thermal imager aimed at the dust layer 11.

[0026] In this embodiment, the output temperature of the temperature heating generator 5 is 0 to 400°C.

[0027] The temperature testing device 7 includes a K-type thermocouple, with temperature measuring points arranged in the middle of the dust layer 11. The thermocouple accuracy is ±1℃, and the data sampling frequency is not less than 10Hz. The data is transmitted to the computer in real time through a data acquisition instrument.

[0028] Example 2 A method for testing the fire hazard of dust inside curved heat sink fins, using the testing device for the fire hazard of dust inside curved heat sink fins described in Example 1, includes the following steps: Step 1: Place base 1 horizontally; Step 2: Under the test conditions of dust layers 11 with different heights of dust accumulation in the curved heat dissipation fin test assembly with different fin spacing, the following operations are performed respectively to obtain the corresponding minimum ignition temperature: Step 2.1: Install the curved heat dissipation fin test assembly on the base 1, so that the curved powder carrier platform 2 is always in a horizontal state, that is, the two sides of the curved powder carrier platform 2 are at the same horizontal height, and the heat dissipation fins 3 are always perpendicular to the horizontal plane. Step 2.2: The heating device 4 is connected to the temperature heating generator 5 in sequence through the first wire 9 and the conductive connector 8; the temperature testing device 7 is connected to an external computer through the second wire 12. Step 2.3: Start the temperature heating generator 5 and the temperature testing device 7; Step 2.4: Pour the dust to be tested into the curved heat sink test component and test the lowest ignition temperature of the corresponding dust layer 11; Step 2.5: Stop the temperature heating generator 5 and the temperature testing device 7, so that the temperature of the heating device 4 and the dust layer 11 on the heating device 4 is reduced to room temperature.

[0029] The dust height is the height difference between the highest horizontal level of the dust layer 11 accumulated on the heating device 4 and the lowest horizontal level of the dust layer 11.

[0030] For each test condition, step 2.4 specifically includes the following steps: Step 2.4.1: Control the temperature heating generator 5 to make the temperature of the heating device 4 equal to the preset initial temperature. In this embodiment, the preset initial temperature is 400℃. Step 2.4.2: Slowly pour the dust to be tested into the curved powder carrier stage 2 so that the dust falls into the gaps between the heat dissipation fins 3. Use the scraper 6 to smooth the upper surface of the dust layer 11, and then clean up the dust scattered around the curved powder carrier stage 2 to complete the preparation of the dust layer. In this embodiment, the dust is filled into the curved powder carrier stage 2 within 2 minutes to improve the accuracy of the experiment. Step 2.4.3: Keep the temperature of the heating device 4 constant, and continuously observe the state of the dust layer 11 in real time through the temperature testing device 7, high-speed camera and infrared thermal imager; a) When dust layer 11 is observed to be on fire: If it is the first round of observation, or if it is not the first round of observation and the dust layer 11 also caught fire in the previous round of observation, then reduce the temperature of the temperature generator 5, remove the dust layer 11 on the curved powder carrier stage 2, replace the dust to be tested at room temperature, and return to step 2.4.2. If it is not the first round of observation and the dust layer 11 did not ignite in the previous round of observation, then the control temperature of the temperature generator 5 (which is equal to the temperature of the heating device 4, i.e. the hot surface temperature) is the minimum ignition temperature. b) If no fire is observed in the dust layer 11 within 30 minutes or longer (including two situations: 1. the dust self-heats, 2. the dust temperature rises but does not exceed the control temperature of the temperature generator 5), and the control temperature displayed by the temperature generator 5 does not reach 400°C: If it is the first round of observation, or if it is not the first round of observation and the dust layer 11 did not ignite in the previous round of observation, then increase the control temperature of the temperature generator 5 to raise the temperature of the heating device 4 (i.e., the hot surface temperature), remove the dust layer 11 in the curved powder carrier stage 2, replace the dust to be tested at room temperature, and return to step 2.4.2. If it is not the first round of observation and the dust layer 11 was on fire in the previous round of observation, then the control temperature of the heating generator 5 corresponding to the temperature in the previous round of observation is the minimum ignition temperature; c) When the controlled temperature of the temperature heating generator 5 reaches 400℃ (i.e., the hot surface temperature is equal to 400℃), and the dust layer 11 does not ignite for 30 minutes or longer, it indicates that the dust layer 11 is not easy to ignite under the test conditions; step 2.5 can be selected.

[0031] The highest unignited temperature should be lower than the lowest ignition temperature, and the difference should not exceed 10℃. Therefore, in step 2.4.3, when adjusting (raising or lowering) the control temperature of the temperature generator 5, the difference between the control temperature of the temperature generator 5 before and after the increase or decrease should be less than 10℃.

[0032] Among them, the dust layer 11 is determined to be on fire if the following situation is observed by the temperature testing device 7, high-speed camera and infrared thermal imager: The dust layer 11 was observed to be burning with or without flame using a high-speed camera and an infrared thermal imager. The temperature of the dust layer 11 was observed by the temperature testing device 7 to be 250°C higher than the control temperature (equal to the hot surface temperature) of the temperature heating generator 5. The temperature of the dust layer 11 was observed to reach 450°C using the temperature testing device (7).

[0033] Among them, the following phenomenon was observed through the temperature testing device 7, which determined that the dust was self-heating: the temperature of the dust layer 11 slowly rose and exceeded the hot surface temperature, and then gradually dropped to a stable value below the hot surface temperature.

[0034] The dust height of dust layer 11 under different test conditions is controlled in the following way: For each test condition, the fin height of the heat dissipation fin 3 in the selected curved heat dissipation fin test assembly is equal to the required dust height. In step 2.4.2, the scraper 6 scrapes the upper surface of the dust layer 11 flat and makes the dust height of the dust layer 11 flush with the fin height of the heat dissipation fin 3. As another possible implementation, in the curved heat sink fin test assembly, the fin height of the heat sink fin 3 is higher than the dust height required under all test conditions. The corresponding scraper 6 includes a comb-shaped brush, and the width of the teeth corresponds to the fin spacing under the corresponding test conditions. In step 2.4.2, the scraper 6 flattens the upper surface of the dust layer 11 and makes the dust height of the dust layer 11 equal to the dust height required under the corresponding test conditions. In order to accurately control the thickness of the dust layer 11, a scale 10 is provided on the outer surface of the heat sink fin 3 (i.e., the surface of the heat sink fin 3 that is not directly opposite other heat sink fins 3). The dust height can be displayed intuitively through the scale 10, ensuring accurate control of structural parameters during the test. In this embodiment, the smallest scale unit of the scale 10 is set to 0.5cm.

[0035] Furthermore, for each curved heat dissipation fin test assembly of each fin specification, steps 2.4.1 to 2.4.3 are repeated at least three times. The average of the lowest ignition temperature obtained from the repeated tests is taken as the final lowest ignition temperature under the corresponding test conditions to ensure the accuracy of the experiment.

[0036] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A testing device for the fire hazard of dust inside curved heat sink fins, comprising a base (1), characterized in that, The base (1) is placed horizontally, and a detachable curved heat dissipation fin test assembly is provided on the base (1). The curved heat dissipation fin test assembly includes a curved powder carrier platform (2) placed on the base (1). The two sides of the curved powder carrier platform (2) are located on the same horizontal plane. A heating device (4) is laid on the upper surface of the curved powder carrier platform (2). Multiple heat dissipation fins (3) are provided on the heating device (4). The heat dissipation fins (3) are arranged in parallel with equal spacing. Dust from the dust layer (11) to be tested falls into the gap between the heat dissipation fins (3), and a temperature testing device (7) is inserted into the dust layer (11). The temperature testing device (7) is connected to an external computer. The heating device (4) is electrically connected to the temperature heating generator (5) in sequence through the first wire (9) and the conductive connector (8).

2. The testing device for the fire hazard of dust inside curved heat dissipation fins according to claim 1, characterized in that, The base (1) and the curved powder carrier (2) are both made of insulating material; the scraper (6) is made of metal material.

3. The testing device for the fire hazard of dust inside curved heat dissipation fins according to claim 1, characterized in that, It also includes a high-speed camera and an infrared thermal imager, with the image acquisition lenses of the high-speed camera and the infrared thermal imager aimed at the dust layer (11).

4. A method for testing the fire hazard of dust inside curved heat sink fins, utilizing any one of the testing devices for the fire hazard of dust inside curved heat sink fins as described in claims 1-3, characterized in that... Includes the following steps: Step 1: Place the base (1) horizontally; Step 2: Under the test conditions of dust layers (11) of different heights accumulated in the curved heat dissipation fin test assembly with different fin spacing, the following operations were performed respectively: Step 2.1: Install the curved heat sink test assembly on the base (1) so that the two sides of the curved powder carrier stage (2) are at the same horizontal height, and the heat sink (3) is always perpendicular to the horizontal plane. Step 2.2: The heating device (4) is connected to the temperature heating generator (5) in sequence through the first wire (9) and the conductive connector (8); the temperature testing device (7) is connected to the external computer through the second wire (12); Step 2.3: Start the temperature heating generator (5) and the temperature testing device (7); Step 2.4: Pour the dust to be tested into the curved heat sink test assembly and test the lowest ignition temperature of the corresponding dust layer (11); Step 2.5: Stop the temperature heating generator (5) and the temperature testing device (7).

5. The test method for the fire hazard of dust inside curved heat dissipation fins according to claim 4, characterized in that, Step 2.4 specifically includes the following steps: Step 2.4.1: Control the temperature of the heating generator (5) to make the temperature of the heating device (4) equal to the preset initial temperature; Step 2.4.2: Slowly pour the dust to be tested into the curved powder carrier platform (2) so that the dust falls into the gap between the heat dissipation fins (3). Use the scraper (6) to scrape the upper surface of the dust layer (11) flat, and then clean up the dust scattered around the curved powder carrier platform (2). Step 2.4.3: Maintain a constant temperature for the heating device (4) and continuously observe the state of the dust layer (11) in real time. a) When the dust layer (11) is observed to be on fire: If it is the first round of observation, or if it is not the first round of observation and the dust layer (11) of the previous round of observation also caught fire, then lower the temperature of the temperature heating generator (5), remove the dust layer (11) on the curved powder carrier stage (2), replace the dust to be tested at room temperature, and return to step 2.4.2; If it is not the first round of observation and the dust layer (11) did not ignite in the previous round of observation, then the control temperature of the temperature heating generator (5) is the minimum ignition temperature at this time; b) If no dust layer (11) is observed to ignite within 30 minutes or longer, and the control temperature displayed by the temperature generator (5) does not reach 400°C: If it is the first round of observation, or if it is not the first round of observation and the dust layer (11) in the previous round of observation does not ignite, then increase the control temperature of the temperature generator (5) to raise the temperature of the heating device (4), remove the dust layer (11) in the curved powder carrier stage (2), replace the dust to be tested at room temperature, and return to step 2.4.2; If it is not the first round of observation and the dust layer (11) was on fire in the previous round of observation, then the control temperature of the heating generator (5) corresponding to the temperature in the previous round of observation is the lowest ignition temperature; c) When the temperature of the temperature generator (5) reaches 400°C and the dust layer (11) does not ignite for 30 minutes or longer, it indicates that the dust layer (11) is not easy to ignite under the test conditions.

6. The test method for the fire hazard of dust inside curved heat dissipation fins according to claim 5, characterized in that, The dust layer (11) is considered to be on fire if any of the following conditions are observed: The dust layer (11) was observed to be either burning with flame or without flame using a high-speed camera and an infrared thermal imager. The temperature of the dust layer (11) was observed by the temperature testing device (7) to be 250°C higher than the control temperature of the temperature heating generator (5); The temperature of the dust layer (11) was observed to reach 450°C using the temperature testing device (7).

7. The test method for the fire hazard of dust inside curved heat dissipation fins according to claim 5, characterized in that, In step 2.4, steps 2.4.1 to 2.4.3 are repeated at least three times, and the average value of the lowest ignition temperature obtained from the repeated tests is taken as the final lowest ignition temperature under the corresponding test conditions.

8. The test method for the fire hazard of dust inside curved heat dissipation fins according to claim 5, characterized in that, In step 2.4.3, the temperature difference between the temperature of the temperature generator (5) before and after the temperature increases or decreases is less than 10℃.

9. The test method for the fire hazard of dust inside curved heat dissipation fins according to claim 5, characterized in that, The dust height of the dust layer (11) under different test conditions was controlled in the following manner: For each test condition, the fin height of the heat dissipation fin (3) in the selected curved heat dissipation fin test assembly is equal to the required dust height. In step 2.4.2, the scraper (6) scrapes the upper surface of the dust layer (11) flat and makes the dust height of the dust layer (11) flush with the fin height of the heat dissipation fin (3).

10. The test method for the fire hazard of dust inside curved heat dissipation fins according to claim 5, characterized in that, The dust height of the dust layer (11) under different test conditions was controlled in the following manner: In the curved heat dissipation fin test assembly, the fin height of the heat dissipation fin (3) is higher than the dust height required under all test conditions. The corresponding scraper (6) includes a comb-shaped brush with the width of the teeth corresponding to the fin spacing under the corresponding test conditions. In step 2.4.2, the scraper (6) flattens the upper surface of the dust layer (11) and makes the dust height of the dust layer (11) equal to the dust height required under the corresponding test conditions.

Images