基于火焰蔓延仪的典型换流变压器绝缘油燃烧特性试验研究

利用火焰蔓延仪开展了不同油层厚度和外加辐照强度对典型换流变压器KI50X型绝缘油的点燃时间、热释放速率、CO及烟气生成速率等燃烧特性影响的试验研究,并计算了绝缘油的火灾增长系数。结果表明:KI50X型绝缘油的点燃时间随着外加辐照强度的增大先迅速缩短,而后缓慢缩短,且随着油量的增加其点燃时间先增加后下降,随后保持在40 s左右;本试验中,当油层厚度为4.4 mm以上时,能够完整观察到池火5个典型的燃烧状态,并且绝缘油的热释放速率(HRR)的变化趋势能够与之对应;随着油量的增加,绝缘油燃烧效率先降低后保持不变;随着外加辐照强度的增加,绝缘油燃烧效率下降;就火灾增长系数而言,外加辐照强度的增加导致绝缘油的火灾危险性增大,而油量的增加并未导致其火灾危险性持续增加;峰值HRR在5 mL油量下不到400 kW/m^2,随着油量的快速增加,峰值HRR增速放缓,在50 mL油量时,峰值HRR不到900 kW/m^2,而随着辐照强度的增加,在辐射强度为5~10 kW时峰值HRR出现了显著增长,但随后峰值HRR在800 kW/m^2附近微弱波动。

Empirical Study on the Combustion Characteristics of Insulating Oil in Typical Converter Transformers Based on Fire Propagation Apparatus

This paper explores the effects of different oil surface thickness and irradiation intensity on the ignition time,heat release rate,CO and smoke generation rate of typical converter transformer insulating oil KI50 X by fire propagation apparatus(FPA),and calculates the fire growth factor.The results show that the ignition time of KI50 X insulating oil decreases with the increase of irradiation intensity,the ignition time increases first and decreases with the increase of oil content,and remains at about 40 s.In this experiment,when the oil thickness is above 4.4 mm,five typical combustion states of pool fireare can be fully observed,and the change trend of heat release rate of insulation oil can correspond to them.With the increase of oil content,combustion efficiency of insulation oil decreases first and then remains unchanged;with the increase of external irradiation intensity,combustion efficiency decreases.As far as the fire growth factor is concerned,the increase of external irradiation intensity leads to the increase of fire risk of insulating oil,while the increase of oil quantity does not lead to the continuous increase of fire risk.The peak HRR increases rapidly from less than 400 kW/m^2 at 5 mL oil volume,then slows down.At 50 mL oil volume,the peak HRR is less than 900 kW/m^2.With the increase of irradiation intensity,the peak HRR increases significantly from 5 kW to 10 kW,but then the peak HRR fluctuates slightly around 800 kW/m^2.