In the multi-effect evaporation process in Bayer process for alumina production

liquid level of each effect is an important parameter that influences other parameters and important for optimization of evaporator operation. But in the actual production

the liquid level is usually set empirically in a large rang

so that the process cannot run in optimal situation. This paper proposed a liquid level optimization method based on exergy analysis. By deeply analyzing the liquid level's effect on other evaporation parameters and using the actual running data

the relationships between liquid level and other parameters are obtained. Combining the material balance of the evaporator and the exergy analysis method

optimization model for energy consumption based on the maximum exergy efficiency is established. The optimization model is then solved by STA using two different constraint handling technology under a certain condition to get better solutions. Finally the optimal level under three different pickling cycle is calculated and evaporation liquid level curve for each effect is obtained.