低浓度煤层气深冷分离数值模拟研究

Numerical Simulation Study on Cryogenic Separation of Low-concentration Coal-bed Methane

通过数值模拟对低浓度煤层气深冷液化用的精馏塔进行了研究。结果表明:根据数值模拟得到的数据设计的精馏塔在中试装置运行情况良好,模拟结果可信;回流比增加,塔板数减少,但塔的能耗增加,应综合考虑整体经济性,选择适当的回流比;进料位置对精馏塔的能耗也有影响,存在一个最佳的进料位置;对于浓度为35%的低浓度煤层气深冷液化装置,精馏塔的实际回流比取1.513,装置塔板效率取0.7,实际塔板数为32;最佳进料位置为从第9块塔板上进料。

Numerical simulation was carried out on the rectifying column used in the low-concentration coal-bed methane cryogenic liquefaction device. The results indicated that the rectifying column which was designed according to the data obtained by numerical simulation operated well in the pilot device, the simulated results were credible; the reflux ratio increased, the number of the column plates was reduced, but the energy consumption of the rectifying column increased, so proper reflux ratio should be selected by the overall economy; the feed position also had influence on the energy consumption of the rectifying column, and there was an optimum feed position; for the cryogenic liquefaction device of the coal-bed methane in low concentration of 35%, the actual reflux ratio of the rectifying column was 1. 513, the efficiency of the column plates in the device was 0. 7, the actual number of plates was 32;and the optimal feed position was the 9th plate.