aspen dynamics的flow driven和 p driven？ 哈哈，看《aspen dynamics user guide》正好看到这儿了，下面是原话： flow driven simulations in an aspen plus steady-state simulation, the outlet stream pressures and flow rates of a block are determined from the inlet conditions to the block, and the specifications for the block. neither the outlet stream pressures or flow rates are affected by the pressure in the downstream blocks. this approach is called flow driven simulation. flow driven dynamic simulations work in the same way as in aspen plus simulations. for each model, fixed rules are used to determine outlet flow rates and pressures, given the inlet conditions to the block. in some cases, the outlet stream flow rates are determined by pressure or level controllers which are automatically added when the dynamic simulation is created. the rules used for each model are given in the aspen dynamics reference. the flow driven approach is well suited to a wide range of dynamic simulation applications. in effect, this approach makes the assumption of perfect flow control. this is often a good assumption, particularly when modeling liquid only systems. for liquids, the pressure/flow dynamics are very fast, and the assumption of perfect flow control is usually accurate. pressure driven simulations in some simulations, it is necessary to take into account the effect of downstream pressures on flow rates in streams. for example, consider two tanks containing vapor that are connected by a valve. the pressure in the two tanks determines the flow rate through the valve. if the pressure rises in the downstream tank then the flow between the tanks will decrease, as the pressure driving force is reduced. to account for the effect of downstream pressure, it is necessary to create a pressure driven simulation. in pressure driven simulations: • the pressures of all feeds and products to the flowsheet are fixed • feed flow rates are not fixed • all flow rates in the flowsheet are determined by the pressures and pressure/flow relationships around the flowsheet 正好有热心网友帮我们翻译好了，以下文字转自 http:///html/200912/1754110.html 流量驱动的模拟 在aspen plus的稳态模拟中，模块的出口物流压力与流量由模块的进料状况与模块参数决定，都不受下游模块的压力影响。这种方法叫做流量驱动的模拟。 流量驱动的动态模拟与aspen plus中一样。对于每个模型，给定了进料参数与模块参数有固定的规则来决定出口流率与压力。有些情况下，在动态模拟转化过程中，自动生成由压力和液位控制器决定的出口流率。对于每个模块的规则，可以参考aspen plus dynamics reference。 流量驱动的模拟可以进行大部分的动态模拟应用。实际上，这种方法假设了完美的流量控制。这种假设通常比较合适，尤其是模拟仅有液体的系统。对于液体， 压力/流量动力学非常快，完美流量控制的假设通常是准确的。 压力驱动的模拟 有些模拟中，有必要考虑下游压力对于流量的影响。 例如,考虑由一个阀连接的气体罐，两个罐中的压力决定了通过阀的流量。如果下游罐的压力增加，则流量减少，因为压差驱动力减少了。为了考虑下游压力的影响，有必要进行压力驱动的模拟 在压力驱动的模拟中： • 所有进料与产物的压力是固定的（fixed） • 进料流量是不固定的（not-fixed） • 流程中所有的流量都由压力、压力与流量的关系来决定 通常，一些被简化的模型不支持在压力驱动的动态模拟中进行，因为它们将导致流程中的流量的过度约束。查看更多
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