The occurrence of boiler tube burst seriously affects the safety of the boiler and the economy of the unit operation. Very likely to cause injury to operators, the following Shandong Gas Boiler Factory will summarize the causes of the boiler tube burst, I hope you pay more attention to it, to help you all! 

（1）锅炉运行中操作不当，炉管受热或冷却不均匀，产生较大的应力。

(1) The operation of the boiler is improper, and the heating or cooling of the furnace tube is not uniform, resulting in greater stress.

1)冷炉进水时，水温或上水速度不符合规定；启动时，升温升压或升负荷速度过快；停炉时冷却过快。

1) When the cooling furnace feeds water, the water temperature or feeding speed does not conform to the regulations; when starting, the speed of temperature and pressure rise or load increase is too fast; when stopping the furnace, the cooling rate is too fast.

2)机组在启停或变工况运行时，工作压力周期性变化导致机械应力周期性变化；同时，高温蒸汽管道和部件由于温度交变产生热应力，两者共同作用造成承压部件发生疲劳破坏。

2) The cyclical change of working pressure leads to the cyclical change of mechanical stress during start-up, shut-down or off-design operation of units; meanwhile, the thermal stress of high-temperature steam pipes and components due to temperature alternation causes the fatigue damage of pressure components.

（2）运行中汽温超限，使管子过热，蠕变速度加快

(2) In operation, the steam temperature exceeds the limit, which makes the pipe overheated and the creep speed accelerated.

1)超温与过热。

1) Overheating and overheating.

过热可分为长期过热和短期过热两大类，长期过热爆管是指金属在应力和超温温度的长期作用下导致爆破，其温度水平要比短期过热的水平低很多，通常不超过钢的临界点温度。

Overheating can be divided into two categories: long-term overheating and short-term overheating. Long-term overheating tube explosion refers to metal explosion under long-term stress and overheating temperature. Its temperature level is much lower than that of short-term overheating, and usually does not exceed the critical temperature of steel.

超温是指金属超过额定温度运行。超温分为长期超温和短期超温，长期超温和短期超温是一个相对概念，没有严格时间限定。超温是指运行而言，过热是针对爆管而言。

Overtemperature refers to the operation of metals above rated temperature. Overtemperature can be divided into long-term overtemperature and short-term overtemperature. Long-term overtemperature and short-term overtemperature are relative concepts without strict time limit. Overheating refers to operation, and overheating refers to explosion.

短期过热爆管是指，在短期内由于管子温度升高在应力作用下爆破，其温度水平较高，通常超过钢的临界点温度，会导致金属组织变化发生相变。

Short-term superheated tube blasting refers to the high temperature level of tube blasting under stress in a short time due to the increase of tube temperature, which usually exceeds the critical point temperature of steel, leading to the transformation of metal structure.

2)热偏差

2) thermal deviation

影响热偏差的主要因素是热应力不均和水力不均。

The main factors affecting thermal deviation are uneven thermal stress and hydraulic pressure.

3)传热恶化

3) Deterioration of heat transfer

类传热恶化也称作膜太沸腾，是指管外热负荷过大，因管壁形成汽膜导致的沸腾传热恶化。

The first type of heat transfer deterioration, also known as membrane boiling, refers to the deterioration of boiling heat transfer caused by the excessive heat load outside the tube and the formation of vapor film on the tube wall.

类传热恶化所对应的临界热负荷非常大，大型电站锅炉一般不会发生。

The critical heat load corresponding to the deterioration of the first type of heat transfer is very large, and large utility boilers generally do not occur.

第二类传热恶化即管内环状流动的水膜被撕破或者“蒸干”。发生第二类传热恶化的热负荷低于类传热恶化的热负荷值。直流炉因加热、蒸发、过热三阶段无明显分界点，工质含汽率x 由0逐渐上升到1，发生第二类传热恶化不可避免。

The second type of heat transfer deterioration is that the annular flow of water film in the tube is torn or "steamed dry". The heat load of type II heat transfer deterioration is lower than that of type I heat transfer deterioration. Because there is no obvious boundary point in three stages of heating, evaporation and overheating, the vapor content x of working medium gradually rises from 0 to 1, and the second type of heat transfer deterioration is inevitable.

直流锅炉蒸发受热面的沸腾传热恶化现象主要与工质的质量流速、工作压力、含汽率和管外热负荷有关。

The deterioration of boiling heat transfer on evaporative heating surface of once-through boiler is mainly related to mass flow rate, working pressure, vapor content and heat load outside the tube.

（3）受热面磨损

(3) Wear of heating surface

受热面磨损是由含灰气流对受热面冲刷撞击造成的。受热面磨损的速度与气流速度的三次方成正比，与飞灰浓度成正比，与管子的排列方式、管子的耐磨性能有关，同时，飞灰硬度、形状、直径大小也是影响受热面磨损速度的因素。

The wear of the heating surface is caused by the erosion and impact of the ash-containing air flow on the heating surface. The wear rate of heating surface is directly proportional to the cubic power of air velocity and fly ash concentration. It is related to the arrangement of pipes and the wear resistance of pipes. At the same time, the hardness, shape and diameter of fly ash are also factors affecting the wear rate of heating surface.

受热面磨损是省煤器爆管的主要原因。

Wear of heating surface is the main cause of tube burst of economizer.

（4）受热面腐蚀。

(4) Corrosion of heating surface.

1)炉管内高温氧化腐蚀。受热面管子中铁离子在一定的温度下氧化，随着受热面壁温度升高，氧化速度不断加快；当温度高于580℃时，炉管金属内壁氧化皮层由FeO、Fe2O3、Fe3O4三种氧化物组成，靠近金属的氧化物FeO构成氧化层的主要部分。

1) High temperature oxidation corrosion in furnace tube. The oxidation rate of iron ions in heating surface tubes is accelerated with the increase of heating surface temperature at a certain temperature. When the temperature is higher than 580 C, the oxide layer of inner metal wall of furnace tubes is composed of three oxides: FeO, Fe2O3 and Fe3O4, and the oxide FeO near the metal is the main part of the oxide layer.

2)炉管内结垢、腐蚀。给水品质不良，炉水品质差，引起炉管管内结垢，结垢后易产生垢下腐蚀。同时，结垢使传热热阻增大，管壁温度上升，强度减弱，发生爆管。

2) Scaling and corrosion in furnace tubes. The poor quality of feed water and the poor quality of furnace water cause scaling in the furnace tube, and corrosion under scaling easily occurs after scaling. At the same time, scaling increases heat transfer resistance, increases wall temperature, weakens strength and bursts occur.

3)受热面的高温黏结灰和高温腐蚀。在高温烟气环境中，飞灰沉积在受热面管子表面，烟气和飞灰中的有害成分（复合硫酸盐）会与管子金属发生化学反应，使管壁减薄、强度降低，称为高温腐蚀。

3) High temperature bonding ash and high temperature corrosion of heating surface. In high temperature flue gas environment, fly ash deposits on the surface of heating surface pipes. The harmful components (compound sulfate) in flue gas and fly ash will react with the metallic elements of pipes, making the pipe wall thinner and the strength lower, which is called high temperature corrosion.

4)制造、安装、检修质量不良。如管材或管子钢号错误、管子焊口质量不合格、弯头处管壁严重减薄。

4) The quality of manufacture, installation and overhaul is poor. If the pipe or pipe steel number is wrong, the quality of the pipe weld is not qualified, and the pipe wall at the elbow is seriously thinned.

这就是今天给大家介绍的纯干货的内容了，相信今天的内容能给打击带来一定的帮助，如果您对文章的内容还有不明白的地方，欢迎大家点击我们的网站留言讨论：山东燃气锅炉 http://www.jnlzsb.com

This is the content of the pure dry goods introduced to you today. I believe that today's content can bring some help to the crackdown. If you still don't understand the content of this article, you are welcome to click on our official website to discuss: Shandong Gas Boiler http://www.jnlzsb.com.