Effects of Radiation on Temperature Measurement in a Fire Environment
Effects of Radiation on Temperature Measurement in a Fire Environment
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DOI：
10.1177/073490419701500602
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发表时间：
1997-11
影响因子：
1.9
通讯作者：
Mingchun Luo
中科院分区：
文献类型：
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作者：
Mingchun Luo
热电偶已广泛用于研究和工业中的温度测量。对于建筑火灾实验而言，热电偶已经并将成为获取火灾环境温度场、从而量化建筑火灾强度的主要仪器。已经发现辐射误差显着影响使用热电偶测量的温度。然而，这个问题在建筑火灾研究领域尚未得到认真研究。设计了吸入式高温计并将其应用于全尺寸实验建筑火灾设施的一系列火灾实验中，以避免辐射对测量温度的影响。结果发现，在明火阶段，裸热电偶的读数可能比吸入高温计获得的气体温度高出 100°C 以上，在闪络阶段则高出 200°C 以上。对于从丙烷气燃烧器火灾获得的稳态火灾环境，天花板附近的热上层的辐射误差可以忽略不计。然而，由于辐射误差，热电偶明显高估了地面附近较冷的较低层中的气体温度超过 80°C。计算流体力学模型CESARE-CFD火灾模型预测的温度与下层辐射校正后的实测温度吻合较好，上层略有偏差。
Thermocouples have been widely used to measure temperature in research and industry. For the purpose of building fire experiments, the thermocouple has been and will be a major instrument to obtain the temperature field of the fire environment, and hence to quantify the intensity of building fire. It has been found that the radiation error significantly affects the measured temperature using thermocouples. However, this issue has not been carefully investigated in the area of building fire research. A suction pyrometer was designed and applied to a series of fire experiments in a full-scale experimental building-fire facility to avoid the effect of radiation on the measured temperature. It was found that the reading from a bare thermocouple could be more than 100°C higher than the gas temperature obtained from the suction pyrometer during the flaming fire stage and more than 200°C higher during the flashover stage. For a steady-state fire environment obtained from a propane gas burner fire, the radiation error was negligible in the hot upper level near the ceiling. However, the thermocouple significantly overestimated the gas temperature by more than 80°C in the cool lower level near the floor because of the radiation error. The temperature predicted by the computational fluid dynamics model, CESARE-CFD fire model, was in good agreement with the measured temperature after the radiation correction in the lower level and deviated slightly in the upper level.