强制内循环煤直接液化反应器流动性能的冷模与热模试验

Cold Model and Process Development Unit Pilot-Plant Tests of Coal Direct Liquefaction in Forced Inner Recycling Reactor

采用玻璃珠-水-空气三相体系在煤直接液化强制内循环浆态床反应器中进行冷模试验,考察了强制内循环反应器内的固含率、气含率、压降、流速分布和湍动强度的分布情况。结果表明:反应器内固含率要高于进料中的固体含量;床层轴向压降保持不变,但受固相含量影响;气含率随床层增高而增加;同一截面上湍流脉动能量径向分布较均匀,而随气体表观速率和浆液表观速率增加,脉动能量增加;反应器内多相流在分布板区强烈混合引起的压力脉动沿轴向向上逐渐衰减;靠近反应器壁的有些区域存在回流现象。测定了工艺开发单元(PDU)中试装置反应器内的液体密度分布,并计算了其气含率。结果表明,冷模试验与PDU中试中的气含率在床层中的变化趋势相同,且反应器具有较好的操作稳定性。

The solid holdup, gas holdup, pressure drop, distribution of slurry velocity and turbulence intensity in the forced inner recycling reactor were investigated through the cold model test using glass bead-water-air system. The results showed that the solid holdup in the reactor was higher than that in feed, the pressure drop remained unchanged along the axial bed but was influenced by the content of solid in feed; gas holdup increased with the increase of bed height; on the same cross section, the radial distribution of momentum of turbulence was uniform, and with the increase of superficial velocity of gas and slurry, the momentum of turbulence increased; the pressure fluctuation caused by the strong mixing gradually weakened along the axial bed; there was backflow in some region close to the wall of the reactor. The distribution of liquid density and gas holdup in the process development unit （PDU） were obtained, which indicated that the changing trend of gas holdup in the bed obtained from cold model test were similar and the reactor exhibited good operational stability.