氟利昂预冷双氮膨胀液化工艺动态仿真与验证

为了研究带预冷的双氮膨胀液化工艺的动态特性,在小型撬装液化实验装置基础上建立相应的工艺动态模型,对电磁阀的流量系数进行微调,以适应蒸发器热负荷的变化;对压缩机控制与启动、预冷机组能量调节、LNG节流控制等实验工况进行仿真,并与实验结果进行对比。结果表明:氮气压缩机的控制与启动与实验测试结果一致,验证了压缩机控制动态模型的准确性;预冷机组能量调节受电磁阀流量系数的影响。 LNG节流阀串级控制有效克服了温度响应的滞后,提高了控制质量。动态仿真可优化天然气液化工艺设计,指导设备的操作和运行,提高装置的安全性。
A dynamic simulation model based on a small-scale natural gas liquefaction facility was established in order to study the dynamic characteristics of the natural gas liquefaction process with dual nitrogen expanders and pre-cooling. Different processes involved in the liquefaction were simulated and compared with experimental results, including the compressor starting and control, the energy regulation of the pre-cooling system and LNG throttle control. The results show that the simulation results of the compressor starting and control process were consistent with the experimental results, verifying the effectiveness of the dynamic model. The performance of the pre-cooling system for energy regulation can be affected by the flow coefficient of the electromagnetic valve, which needs to be adjusted to adapt to the thermal load of the evaporator. The delay of temperature response can be effectively reduced by LNG throttle cascade control, which can increase the control quality. The results show that, through the dynamic simulation, the design of the natural gas liquefaction process can be optimized, and the operation of the equipment can be well supervised for improved safety control