废热水闪蒸汽系统改造

Transformation of Waste Heat Water Flash Steam System

中国石化长城能源化工(宁夏)有限公司聚乙烯醇运行部回收三塔废热水闪蒸汽流量波动频繁,对聚合二塔造成干扰,严重影响聚合二塔正常操作,因此闪蒸系统无法正常投入使用,蒸汽被放空,造成能源浪费。其原因主要是回收三塔中温波动频繁,于是采取了闪蒸汽至聚合二塔再沸器流量自动控制,稳定了闪蒸汽流量,并对回收三塔废热水槽压力实行压力补偿调节,稳定了闪蒸汽压力,实现了废热水闪蒸汽系统的稳定运行,每年可节约0.4 MPa蒸汽20 119.8吨,约107万元。

In the polyvinyl alcohol （PVA） unit of Sinopec Great Wall Energy ＆ Chemical （Ningxia） Co. Ltd., the unstable waste-hot-water flash steam flow in the third recycling column interfered with the second polymerization column, seriously affecting its normal operation. Therefore the flash system was idled and the steam was vented, resulting in energy waste. The unstable temperature in the third recycling column was identified as the main cause. Hence automatic control of flash steam flow to the second polymerization column reboiler was used to stabilize the flash steam flow, and the waste water flume pressure was adjusted and compensated to stabilize the flash steam pressure, which has realized stable operation of the waste-hot-water flash steam system, saving 20. lk tons of 0.4 MPa steam, or about 1.07 million yuan.