加热炉改烧煤焦油存在的问题

Problems of adopting coal tar in heater

针对新乡输油处卫辉站近两年加热炉改烧煤焦油代替原油燃料出现的加热炉效率低、烧嘴磨损、风盘结焦、受热面结垢等诸多问题,对煤焦油的燃烧特性进行分析,结果发现:与原油相比,煤焦油具有灰分和水分含量大、可燃成分含量低、热值低、闪点高等缺点,因此导致煤焦油点火困难,加热炉燃烧不稳定。对加热炉改烧煤焦油后的炉膛温度、排烟温度、热效率等参数以及各项热损失进行校核计算,结果表明:加热炉传热条件变差,排烟热损失、不完全燃烧热损失增大,大大降低了加热炉热效率。因此,严格控制煤焦油质量、开发煤焦油专用燃烧器和增大加热炉受热面成为解决问题的关键。

In recent years,Weihui Pump Station in Xinxiang Oil Transportation Company has changed crude oil to coal tar as heater’s fuel, however,some problems such as low thermal efficiency,burner abrasion,fan-coil coking and heating surface scaling have been found. Analysis results about the combustion characteristics of coal tar show that ash and water content are higher compared with crude oil,while the content of combustible component is lower. Moreover,low heat value and higher flash point of coal tar result in difficult ignition and unstable burning. Correction calculation on heater temperature,exhausting temperature,thermal efficiency,thermal loss and other parameters is carried out. The result shows that heat transfer conditions of heater turns worse, while thermal loss of flue exhausting and incomplete combustion are increased,so the thermal efficiency of heater is obviously declined. Thus,coal tar content controlling,special burner for coal tar and increasing heating surface are keys to solve these problems.