LNG装置部分负荷下动态特性的仿真研究

Simulation of the dynamic performance of LNG plant under partial load

天然气MRC液化装置的动态运行特性对其设计和操作运行有指导意义。MRC系统的动态特性主要取决于循环工况和离心机组运行工况的匹配。采用HYSYS软件建立了液化工艺模型,采用相似准则和工作特性曲线对离心机组的运行工况进行模拟计算。其中特性曲线采用描点并插值查表法进行计算。对部分负荷下液化单元的动态特性进行了仿真研究。在同样转速下只改变冷剂流量对负荷的调节余地较小,因此应通过调节压缩机转速调节负荷。模拟结果还表明每一给定转速下均对应一冷剂流量使液化能力最大,对应另一冷剂流量使单位液化产品的能耗最低。将不同转速下的最高效率点连在一起,即可得到装置负荷调节时的运行工况曲线。

The dynamic performance of a small - scale MRC plant is important for its design and operations. A simulation model of LNG plant which consists of HYSYS cycle model and centrifugal compressor model was established. The dynamic performance of MRC plant under partial load was studied. The. refrigerant flux hardly affected the load and the load should be adjusted by the compressor speed. The results also show that a refrigerant flux corresponding to maximum load and another refrigerant flux corresponding to high energy efficient under a certain compressor speed. A curve through all the high efficient spot is the optimal load -adjustment curve.