The Simulation Of Flow Model & Material Balance In Reactor

Energy saving has been an important target in environmental harnessing engineering now. For biological treatment project to sewage, secondary biological treatment cell is the greatest consuming energy part. In order to resolve the problem about energy consuming in this cell more effectively, it should be researched across microbial kinetics and flow condition of reactor these are two dominating factors effect biological treatment effect and energy consuming. Through simulating the biochemical reactor, the research seeks a tool which can accurately simulate material balance in complicated biochemical reactor, involved in flow model and microbial kinetics, and set a base for energy saving. The clew of research in reactor simulation as follows:1 guiding by the systematic thought that a complicated system is constituted by many simple systems;2 using powerful professional mathematic software MATLAB, which can get numerical solution of reactor model more easily for simulation;3 using simulation tool Simulink attached to MATLAB. It supplies graphics interactive environment, can directly get module needed from module library by mouse dragging to quickly establish system model figure, not need to write any code, then modeling, simulate and analyze the dynamitic system. Therefore, using the Simulink makes the whole simulating process rather conveniently, intuitionistic and having strong portability, then can simulate many complicated system in the method of composing; 4 Considering that the reactor flow model and material balance model are not exactly same. The flow model is established in unstable and no reacting state, but the material balance model is completed in stable and reacting state, so two corresponding emulational module library should be established.So the research based on the establishment of flow model of simple reactors, then found the corresponding material balance model by introducing ASM1 that be put forward by IAWQ. Therefore the material balance model in complicated reactor system can be simulated by assembling modules across microbial kinetics and flow condition of reactor. In practice, firstly, appropriate assembled emulational flow model of reactor can be determined according to residence time distribution (RTD) curve. Next, the assembled emulational material balance model can also be determined by replacing flow model module with material balance module. By this means, the material balance in complicated reactor system can be proper determined.The established flow model library of reactor has included ideal flow model(CSTR and PFR),a nonideal flow model(axial diffusion model)that be used for simulating practice reactor and discussing the status when reactors in series and plus backflow. On above base, by introducing ASM1, the corresponding material balance model library can be established.In the end, the flow model in Modified Integrated Oxidation Ditch process (MIOD) had been simulated by assembling emulational flow models in flow model library of reactor, which had nitrogen and phosphorus removal function. The assembled emulational flow model had been estimated comparing with practical RTD curve. According to the assembled emulational flow model, the assembled emulational material balance model had been completed when taking COD as target, and estimated the result comparing practical value.