Energy Saving Optimizing And Control Of Multi-effect Evaporation Separation Process

In the chemical industry, the energy consumption per unit of output in our country is much higher than in developed countries, the main reason is that the energy consumption of the separation process is far higher than the developed countries. The operation of evaporation, which is energy intensive together with the secondary steam production, is the separation process, so since the energy crisis in the1970s, it is the top priority that is the research on the energy optimizing and effective control of the operation of evaporation.In this paper, the evaporation system is simulated based on the Aspen Plus software. Results the influence of flow rate, temperature, pressures of the evaporating performance, under the condition of the constant other parameters, the change rules on the influence of the operation parameters changes are simulated. At the same time, it sets up three system models of three effect evaporation with different structure, and contrast the energy consumption of each configuration in the different working conditions, this paper concluded that multiple entry preheated systems can be energy-efficient than the evaporation system in general about9.3%, and the single entry preheated could save12%. In order to meet the technological requirements of the consistence of accomplished liquid, the paper obtain the best value of volume fraction through the simulation model with different concentrations, then each effect temperature and pressure parameter has been optimized, finally each parameter is worked out when the energy consumption is minima, the results provides some references for the evaporation system designed in practical production.Based on the dynamics simulation, in the industry background of seawater desalination multi-effect evaporation process, a sensitivity analysis the effects of various operating variables on three effect evaporation separation processes were made in this paper, and the main control parameters are definite, through these parameters, it could realize that the indirect control of product quality parameters of the concentrated brine concentration and the water production are controlled. Through the simulation research of the control effect and the interference, it is proved that the control structure and control strategy meet the requirement of technology control, and it has the good function of anti-interference, the indirect control of the quality index on evaporation of the separation process concentration under the controlled the evaporated pot TBT, pressure and liquid level is accurate and effective.