干煤粉气化工艺煤粉流量调节阀数值模拟

Numerical simulation of regulating valve for pulverized coal in dry pulverized coal gasification process

高压粉煤流量调节阀是在煤气化工艺装置中用于调节氧-煤比的关键设备。利用计算颗粒流体动力学(CPFD)方法对带有稳流管的高压粉煤流量调节阀在100%和16%开度下的工况进行模拟,重点考察了沿程压力、沿程颗粒速度、沿程颗粒质量浓度等流动特性参数的变化。结果表明:气固两相流经过调节阀一定距离后达到稳定流动,稳定流动下100%和16%开度下颗粒平均速度分别为8,6.6 m/s,颗粒平均质量浓度分别为250,240 kg/m^3;基于阀门出口压力、颗粒速度和颗粒质量浓度分布特性的分析,建议稳流管段至少为500 mm以确保气固两相流动充分发展。研究结果对高压粉煤流量调节阀的设计和控制具有一定的参考价值。

Pressurized regulating valve for pulverized coal is a key equipment to regulate the ratio of oxygen to coal in the coal gasification process. A regulating valve for pulverized coal with flow-stabilizing pipe was simulated by using computational particle fluid dynamics(CPFD) method. The valve was operated at conditions of 100% and 16% openings, respectively. The flow parameters including pressure, particle velocity and particle mass concentration along the valve as well as its downstream pipe were emphatically investigated. The results show that gas-solid flow trends to be stable at the valve downstream with a certain distance, while the average particle velocities are 8 m/s and 6.6 m/s, and the average particle mass concentrations are 250 kg/m^3 and 240 kg/m^3, at valve openings of 100% and 16%, respectively. Based on the analysis of distributions of pressure, particle velocity and particle concentration along the valve as well as its downstream pipe, the distance to reach the stable flow has been obtained. It is suggested that the flow-stabilizing pipe of the valve should be not less than 500 mm to enable the gas-solid flow fully developed. The results can provide useful reference for the design and control of pressurized regulating valve for pulverized coal.