生物质电厂3种管材的耐腐蚀研究及爆管分析

Study of the Corrosion-resistant Performance of Tubes in a Superheater in a Biomass Power Plant and Analysis of the Tube-rupture-caused Corrosion

本文对生物质电厂过热器管主要材料15CrMo、T91、TP316进行了高温氧化动力学试验研究和高温腐蚀动力学研究,分析了其高温腐蚀动力学特点,并以此为基础对生物质电厂现场爆管案例进行测试分析。实验和测试分析表明:生物质电厂过热器材料爆管是由于强侵蚀性的碱金属氯化物直接腐蚀管外侧材料,并形成低熔点灰分加速材料的提前损坏,再加上高温蠕变、蒸汽品质短时期劣化等因素,最终导致过热器爆管断裂,并通过分析相关因素的影响的特点提出了针对性的材料保护方法。

A high temperature oxidation dynamics experimental study and a high temperature corrosion dynamics study were performed of the main materials of the tubes in a superheater in a biomass power plant,their features in high temperature corrosion were analyzed and on this basis,the cases of tube rupture at the site of the biomass power plant were tested and analyzed. It has been found that the rupture of tubes in the superheater in the biomass power plant is caused by the material at the outside of tubes directly corroded by strong corrosive alkali metal chloride,forming ashes having a low melting point to accelerate an advance damage to the material. In addition of the high temperature creep and a deterioration in the quality of steam in a short time period etc. factors,the rupture of tubes in the superheater results eventually. On the basis of the features of relevant influencing factors being analyzed,pertinent material protection methods were proposed.