聚丙烯环形反应器模拟与分析——(Ⅱ)动态特性和操作稳定性

MODELING AND ANALYSIS OF POLYPROPLENE LOOP REACTOR(Ⅱ)DYNAMIC BEHAVIOR AND OPERATING STABILITY

建立了聚丙烯环形反应器动态数学模型,通过模拟计算,研究了工艺参数扰动时聚丙烯环形反应器的动态响应规律、反应器结构参数对动态特性的影响,并对冷却水流量和冷却水入口温度进行了动态操作稳定性分析。

A mathematical model has been established to describe the dynamic behavior of polyproplene loop reactor,and the model has been examined by the steady state model.The responses to the dis= turbances of the cooling water flow,the inlet temperature of reacting mixture,the temperature of cooling water,and the catalyst concentration were studied.The answers of the reacting temperature and the temperature of the outlet cooling water to the disturbances are almost simultaneous,and the answer of the solid ratio is slower than them.The response speed is dependent on the disturbances which can be classified into two sorts,the energy disturbance and the quality disturbance.When the reactor is operated under the oscillation of the catalyst concentration,the yield of the polyproplene is higher than that operated in a steady state. The reactor construction parameters have great influence on the dynamic properties.There are two kinds of response curves,one kind is monotonous,the other kind is fluctuated.Two inequali- ties have been given to show the relations between the construction parameters and the kind of the response curve.As an example,when the operating state is disturbed by a leap of the cooling water flow,the response curve will be monotonous if S(the jacket area)is small or fluctuated if S is large. The flow and the temperature of the cooling water are two important variables of the polyprop- lone loop reactor,and the reactor's dynamic stability under the disturbances of these two variables was analyzed.The dynamic stable regions in two parmeter planes were given,and any pulse distur- bance in the regions cannot change the operating state of the reactor.