红压深冷装置丙烷-膨胀制冷机组优化运行

Optimized Operation of Propane+Expander Refrigeration Unit of Hongya Cryogenic Unit

红压深冷装置采用丙烷-膨胀制冷工艺。该工艺设备运行稳定、制冷效果好,但存在膨胀机易冻堵,丙烷机负荷大、功耗高等问题。为了提高制冷深度、增加轻烃回收率、降低能耗,对大庆油田红压深冷装置的丙烷机和膨胀机进行了优化。优化分为两个步骤,第一步是降低脱甲烷塔塔顶压力,第二步是降低丙烷机负荷、增加膨胀机负荷。实验表明,机组制冷量提高18.5%,每月节电3.4×10^(4) kWh,轻烃收率稳定在1.42~1.44 t/10^(4) m^(3),明显高于优化前的1.40 t/10^(4) m^(3)。实验达到了预期效果,机组最佳运行压力调整为:脱甲烷塔塔顶压力0.84 mPa,膨胀机出口温度-94℃。

Hongya natural gas cryogenic unit adopts propane+expander refrigeration process.The process is stable in operation and has a good cooling effect.However,there are some problems such as the expander is easy to freeze and block,the propane machine has a high load and high power con-sumption.In order to improve refrigeration depth,increase hydrocarbon recovery rate,reduce the en-ergy consumption,optimized operation for propane machine+expander in Hongya natural gas cryo-genic unit is carried out in Daqing Oilfield.The optimized operation is divided into two steps.The first step is to reduce the top pressure of demethanizer and the second step is to reduce the load of propane machine and increase expander load.The test shows that the refrigerating capacity of the unit is increased by 18.5%,saving 3.4×10^(4) kWh of electricity per month,the recovery rate of light hydrocarbon can be stable between 1.42~1.44 t/10^(4) m^(3),which is significantly higher than 1.40 t/10^(4) m^(3) before optimi-zation.The test achieves the expected result,and the best operating pressure of the unit is adjusted at 0.84 mPa top pressure of demethanizer and-94℃expander outlet temperature.