Method for optimizing orifice size of flash evaporation system in alumina dissolving process

Abstract

The invention provides a method for optimizing an orifice size of a flash evaporation system in the alumina dissolving process. A fluid mechanics module of the orifice size when the flash evaporationsystem is in a stable state is established; an optimization model which takes system heat recycling amount maximization as an optimization object and takes a flash evaporation system orifice size model and process indexes as constraints is established; and the optimization model is solved by adopting an adaptive state transition algorithm to obtain an optimal value of the orifice size of each flash evaporator, and the model is verified by adopting actual production data, wherein a transformation factor can be adaptively regulated in each time of iteration process according to a set iteration termination condition, and meanwhile, for to-be-identified parameters which are difficult to measure, identification is carried out according to a least square error function. According to the invention, the orifice size of the flash evaporation system in the alumina dissolving process further accords with the actual environment, so that temperature and pressure distribution of the flash evaporation system is more reasonable, and a heat recycling amount is improved by 0.75% to 1.45%.

Description

technical field [0001] The invention relates to the field of alumina production, in particular to a method for optimizing the orifice size of a flash evaporation system in an alumina dissolution process. Background technique [0002] In the production of alumina by Bayer process, high-pressure dissolution is one of the main energy-consuming processes. This process mainly includes three steps: slurry heating, high-temperature and high-pressure dissolution, and flash evaporation with temperature reduction and pressure reduction. In order to achieve the temperature conditions for dissolution, a large amount of new steam needs to be consumed in the heating process of the slurry, while flash steam is the heat recovery link in the entire dissolution process, and the secondary steam generated by it is used as a preheating heat source in the heating process, which can Effectively reduce the consumption of new steam, so the flash system is of great significance to the energy saving a...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the current actual production, when the feed quantity index changes, the orifice size is set by the workers based on experience, which has a large blindness, and it is easy to make the pressure distribution between the flash evaporators at all levels unreasonable, and it is easy to make the flash evaporator Unsmooth material passing, steam carrying material, resulting in waste of resources and other problems, the invention provides a method for optimizing the orifice size of the flash evaporation system in the alumina dissolution process, including:

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