加热炉炉管节能改造和防护技术探讨

Discussion on Energy Efficiency Upgrades and Protective Technology for Heating Furnace Tubes

某油田拥有200多台火(管)筒式加热炉,由于腐蚀老化、负荷增大以及热洗周期缩短等原因,加热炉损坏和高能耗问题日益突出,每年耗气近9500×104m3,且现场多次发生加热炉着火事故。据统计,损坏的加热炉中,炉管烧损鼓包占53%,烟炉管、封头、烟箱、烟囱腐蚀减薄或穿孔占32%,由此判断炉管是加热炉的易损部件。加热炉炉管鼓包是因为结垢导致炉管上部局部过热以及环境温度变化过大,炉管和弯头等部位的腐蚀主要是因为溶解氧腐蚀、垢下腐蚀及硫酸露点腐蚀。根据加热炉损坏的原因,提出了通过使用FHC-D型红外线新型节能涂料、物理防垢设备、直燃式燃烧器辐射管、炉管高温和泄漏监测装置等防护措施,有效控制炉管损坏问题,并预防因炉管烧穿而引起的火灾事故;此外,在加热炉运行管理中,建议通过推广低温常温集输、加热炉交替使用、合理调整天然气和空气配比等方式,达到减缓结垢速度、保护炉管的目的。

An oilfield has more than 200 fired tube heaters.Due to a combination of factors such as corrosion, aging,higher working load and shortened thermal washing,these heaters have met with increasingly prominent problems including damage and high energy consumption.They use nearly 9500×10^4m3 of gas annually and many fire accidents have occured to these units.Statistics show that 53% of damaged heaters had burning-in- duced damages or swelling of tubes and 32% had corrosion-caused thinning or piercing of boiler tubes,end sockets,smoke chambers or chimneys.From these phenomena,technicians concluded that boiler tubes are dam- ageable parts of the heaters.Tube swelling of the heaters is due to the local overheat in the upper section of the tubes caused by scaling as well as dramatic ambient temperature changes.The corrosions of boiler tubes and bends are primarily due to dissolved oxygen corrosion,under-deposit corrosion and sulfuric acid dew point corrosion.This article proposes some preventive measures based on the factors causing damages of the heaters ,including using the new type of FHC-D infrared energy-saving coating,physical scaling preventing e- quipment,directly fired burner radiant tubes and tube temperature and leakage monitors,to effectively control damage of boiler tubes and prevent fires caused by boiler tubes burnt through.In addition,in regard to daily operation of heaters,the article suggests spreading the use of low-temperature,room-temperature contralized transmission system,using heaters on an alternate basis and properly adjusting the ratio of natural gas to air to retard scaling and protect boiler tubes.