膨胀型防火涂料对高压电力电缆引燃特性影响的实验研究

膨胀型防火涂料在电缆防火工程中有较广泛的应用,在使用过程中确保电缆涂料的效果与经济性具有重要意义。对喷涂不同厚度膨胀型高氯化聚乙烯防火涂料的高压电力电缆开展了在典型强度外加辐射热流条件的着火引燃实验,分析了电力电缆点燃时间、受热期间涂层对电缆外护套的保护与涂层受热后的形态变化。结果表明,电缆的着火行为与涂层厚度紧密相关。相比于未喷涂防火涂料的电缆,覆有膨胀型高氯化聚乙烯防火涂料的电缆在加热过程中明显膨胀,生成较软的泡沫状碳质层,且引燃时间较长,电缆起火后火势较弱。随着涂层厚度的增加,该涂料对电缆的阻燃和保护效果更为显著,研究结果表明,电缆表面喷涂1.0 mm厚度的防火涂料较为适宜。

Experimental study on the influence of intumescent fire-resistant coating on ignition characteristics of high voltage power cables

Expansive fire-resistant coating has been widely used in cable fire protection engineering. It is of great practical significance to ensure the effectiveness and economy of cable coating in the engineering application. The ignition experiment of high-voltage power cables coated with different thick coatings of intumescent HCPE fire-resistant coatings under the condition of typical external radiation heat flux was carried out. The ignition time, protective effect of coating on cable outer sheath during heating and the form change of coating were analyzed. The result shows that the ignition behavior of cable is strongly related to the coating thickness. Compared with the cable without fire-resistant coating, the cable with intumescent HCPE coating obviously swells during the heating and forms a carbon foam layer. In addition, the ignition time of cable with intumescent HCPE coating is longer, and the fire is weaker after the ignition. With the increase of coating thickness, the fire-resistant and protective effects of the coating on the cable are further improved. With consideration of the economy of application, the 1.0 mm thick coating on the cable surface is suggested.