合成氨/尿素装置低品位蒸汽及冷凝液综合利用

Comprehensive Utilization of Low-grade Steam and Condensate of Ammonia/Urea Plant

以某合成氨、尿素工厂为例,分析了9.9 MPa、5.1 MPa、2.5 MPa、1.3 MPa不同等级蒸汽系统的平衡;对0.35 MPa低压蒸汽进行回收利用,主要分为3个方面:低压旋膜除氧器所用蒸汽压力全部改为0.35 MPa、硫酸钠蒸发结晶系统采用0.35 MPa低压蒸汽作热源、将部分循环水泵的驱动方式由电机驱动改为汽轮机驱动;介绍了不同压力等级的透平冷凝液、2.5 MPa和1.3 MPa蒸汽冷凝液、低压冷凝液的综合利用。通过优化改造,实现了能量的梯级利用。

Taking an ammonia plant as an example, the steam systems of 9.9 MPa, 5.1 MPa, 2.5 MPa and 1.3 MPa were analyzed. The 0.35 MPa steam system was recovered and utilized, mainly divided into 3 aspects： changing the steam pressure of the low-pressure rotary membrane deaerator to 0.35 MPa, using 0.35 MPa low-pressure steam as heat source for the sodium sulfate evaporation crystallization system and driving the turbine with saturated steam. Furthermore, condensate could be divided into： turbine condensate, 2.5 MPa and 1.3 MPa steam condensate, and low-pressure condensate. The comprehensive utilization of condensate system with different pressure levels was introduced. Through the optimization, the cascade utilization of energy had been realized.