液氨储罐液体泄漏建模及分析

目的 为了分析液氨储罐纯液体泄漏后的事故影响,探究液氨纯液体泄漏量的计算.方法 针对液氨储罐(卧罐、球罐及立式罐)液体泄漏罐压变化及不同类型储罐结构特征导致液面面积变化的特点,利用范德瓦尔斯方程和流体力学方法,建立液氨储罐液体泄漏模型.利用模型对3种液氨储罐液体泄漏进行数值模拟,对比PHAST计算与模型模拟结果.结论 结果发现液面高度hv,s,h的下降呈现先减缓后增大的趋势,泄漏质量流率Qm-v,s,h的下降幅度及泄漏质量mv,s,h呈现先增加后减缓的趋势.泄漏初始时刻,Qm-v,s,h值最大,分别为0.555,0.553,0.552 kg/s;泄漏停止时,mv,s,h值最大,分别为11.245846,11.084621,7.730932 t.模型计算结果与PHAST模拟结果规律相似,Qm-v,s,h(max)的偏差较小,介于16.577％～16.667％;mv,s,h偏差差别较大,立式罐、球罐及卧罐泄漏液体质量偏差分别为4.565％,5.764％和17.630％.结论 根据各参数的变化规律可得,模型适于计算液氨储罐液体泄漏及风险分析.

Modeling and Analysis of Liquid Leakage in Liquid Ammonia Tank

In the transportation process of production line, the numerical conversion between the actual value and the fuzzy universe is ignored, which leads to the poor effect and low stability of the transportation speed of the production line in different periods, and affects the operation of the transportation equipment of the production line. Therefore, a time-sharing control model of the transportation speed of the production line based on PLC technology is proposed. According to the technical characteristics of PLC, the conveying speed of the production line was calculated, and the quantization factor and scale factor were controlled in different periods to realize the conversion between the actual value of the input instruction and the fuzzy universe. According to the actual demand of the factory for the conveying speed of the production line, the control model of the conveying speed of the production line in different periods is established, and the calculation process of the quantitative factor and the scale factor is substituted to control the conveying speed of the production line in different periods. The experimental results show that the control effect of the conveying speed, the convergence speed of the motor speed waveform and the stability of the model are completely consistent with the speed stage changes generated by the actual control instructions. The maximum convergence speed of the motor speed waveform can reach 1100 r/min, and the amplitude margin is maintained at 10 deg/dB. The time control model of the transportation speed of the production line in this study can control the transportation speed of the production line in time according to the instructions, and in the process of controlling the production line, it has faster response speed and higher stability. The conveying speed of the production line is controlled in different periods, which provides a reference for the intelligent production line.