尿素合成塔风险分析

RISK ANALYSIS OF UREA REACTOR

综述了尿素合成塔的主要失效形式及其原因,建立了尿素合成塔失效的故障树.对所搜集到的资料进行统计得到各基本事件的发生概率,人员伤亡、设备修理和更换成本、生产损失等失效后果以经济损失表述,概率与后果相乘得到风险值.结果表明:衬里泄漏的风险最大,其次是层板应力腐蚀.为了降低风险,建议保持检漏孔通畅并定期检查,一旦发现泄漏立即停车;不用蒸汽检漏,如果确实要用蒸汽检漏,应保证蒸汽质量.

The main failure modes and causes for urea reactors were summarized. A Fault tree for urea reactors was developed. Based on the collected statistics of occurred failures, the probability of each basic event was estimated. The relevant casualties, cost for equipment repair and replacement, as well as production loss due to the failures were expressed in monetary values. The probability and consequence are combined to produce an estimation of risk. The results show that the lining leakage is the most severe risk and the SCC of layer shells risk is the second. The following steps were recommended to decrease the risk： keep weep holes always open and inspect for leaks periodically. Urea reactors should be shut down immediately when a leakage is detected. Don＇t use vapor to detect the leakage of urea reactor vessel,in case it sould be used, the vapor quality should be ensured.