纤维增强塑料排烟内筒高温条件下的性能研究

PERFORMANCE OF FIBER REINFORCED PLASTIC EXHAUST INNER TUBE UNDER HIGH TEMPERATURE CONDITIONS

纤维增强塑料(FRP)排烟内筒被广泛应用于新建燃煤电厂中。本文根据燃煤电厂实际温度工况设计实验,研究了FRP排烟内筒分别在90℃、135℃、180℃高温条件下作用30 d、60 d、90 d后的外观、质量、含胶量、力学性能的变化。并通过对比乙烯基酯树脂在不同温度条件下的力学性能和扫描电子显微镜(SEM)对FRP排烟内筒试样截面的分析结果,着重讨论了FRP排烟内筒高温下的力学性能随时间的变化趋势和原因。研究表明:随着温度的升高,FRP排烟内筒颜色依次加深,180℃高温条件下60 d后试样几乎炭化,呈黑色;高温条件下质量和含胶量的变化是树脂基体的质量变化引起的,最终导致质量和含胶量随着周期变长和温度的升高而减小;力学性能随着时间的变化趋势和乙烯基酯树脂相似,随着时间增加呈现先上升后下降的趋势,在玻璃化转变温度Tg左右的135℃温度下60 d后,力学性能最好。在远高于玻璃化转变温度Tg的180℃温度下,材料力学性能后期下降明显,但作用90 d后仍有80%左右的强度保留率。

Fiber reinforced plastic (FRP) exhaust inner tube is widely used in new coal-fired power plants. In this paper, according to the actual temperature condition design experiment of coal-fired power plant,the changes of appearance, quality, rubber content and mechanical properties of FRP exhaust inner tube in 90 ℃, 135 ℃, 180 ℃ under high temperature conditions were studied in this paper. By comparing the mechanical properties of vinyl ester resin under different temperature conditions and scanning electron microscope (SEM), the analysis results of the cross section of the FRP smoke inner barrel were studied, the change tendency and reason of mechanical properties of FRP smoke inner tube at elevated temperature are discussed emphatically. The results show that the color of the FRP exhaust inner tube is deepened with the increasing of temperature, and the sample is almost carbonized and black at 180 ℃, and the change of mass and rubber content is caused by the quality change of the resin matrix. The result is that the quality and the glue content decrease with the increase of the cycle length and the temperature, and the mechanical properties are similar with vinyl ester resin, and the trend of the increase in the first time is decreased. The mechanical properties of 60 d are best under 135 ℃, which is around the glass transition temperature ( T g). At a temperature of 180 ℃, which is much higher than that of the glass transition temperature, the mechanical properties of the material decreased significantly at the later stage, but it remained about 80% of the strength retention rate.