Mesoscale high heat flux irradiation ignition test system and method

Abstract

The invention provides a mesoscale high-heat-flux irradiation ignition test system and method. The mesoscale high-heat-flux irradiation ignition test system comprises a high-heat-flux irradiation loading module, a test cabin module and a measurement and diagnosis module, the high heat flux irradiation loading module is used for simulating a dynamic high heat flux loading condition in a complex scene; the test cabin module is used for controlling environment parameters of a test; and the measurement and diagnosis module is used for recording images and data. Compared with high-heat-flux irradiation conditions at home and abroad, the method has larger light spots, and the influence of the size effect can be reduced; light intensity distribution is more uniform, and uniform irradiation in an actual working condition can be closer to; and the generated light intensity time waveform curve is closer to a complex dynamic high heat flux curve in an extreme scene.

Description

technical field [0001] The present invention relates to high heat flux (≥ 0.1MW / m 2 ) The field of radiation effect test research, specifically involving a mesoscale (5-10cm level) high heat flux irradiation ignition test system and its method; it is suitable for pyrolysis, ignition and combustion of combustibles under high heat flux irradiation conditions characteristics of the field of fire research. Background technique [0002] The optical radiation generated in extreme scenarios such as propellant fire, strong explosion, industrial explosion, arc discharge, meteorite impact, etc., can lead to the pyrolysis, ignition and combustion of surrounding combustibles, further triggering urban or forest fires. This test method is suitable for simulating the ignition effect of high heat flux irradiation in the above extreme scenarios, which can be used for fire assessment and protection, and is of great significance to the fields of national defense and industry. [0003] First,...

AI Technical Summary

Problems solved by technology

However, the average dispersion of wind speed and wind direction measured in the literature is as high as 34% and 23%, the ambient temperature range is 7-30°C, and the controllability of humidity conditions is also poor

As a result, in the test results of cellulose (Cellulose) materials, the dispersion of pyrolysis delay time and ignition delay time is as high as about 31% and 22% respectively; in addition, experiments cannot be carried out in non-sunny or windy weather

[0005] Finally, in the test and diagnosis methods, on the one hand, optical photography technology is one of the most important means. However, the radiation source in Document 1 is mainly in the visible light band, and the optical camera as an important phenomenon observation method is also based on the visible light band. Highly overlapped, and the intensity of radiated light is much greater than the optical signal intensity of observed objects such as flames, resulting in severe overexposure of the irradiated area or underexposure of the periphery of the irradiated area, and the recognition of the physical image recorded by the camera is not high

On the other hand, by measuring the mass change curve during the test, the converted critical mass flow is one of the important ignition criteria. However, the pyrolysis and ignition response in the high heat flux irradiation test is only about a few tenths of a second to a few seconds. Obtaining enough data points in such a short period of time requires the sampling rate of the balance system to be ≥ 5Hz, but there is no report on relevant testing techniques and methods

Document 1 also only measures the mass change of the sample before and after the test, and cannot obtain the results of critical mass flow, nor can it establish a new criterion for ignition of critical mass flow under high heat flux irradiation conditions

[0006] To sum up, in the existing test systems and methods, there are many differences between the characteristic parameters of irradiation loading and the real scene, the controllability of the test environment parameters is poor, the test results are not comprehensive enough, the physical image is not clear enough, etc. problem, resulting in a large dispersion coefficient of the test result data, which cannot reflect the radiation effect in the real scene

Images