重介质选煤因入选粒度范围宽、分选效率高已成为煤炭分选应用最广泛的方法，重介质悬浮液密度、黏度和旋流器入料压力等过程参数的控制精度直接影响重介质旋流器的分选效果。目前选煤厂通常只对重介质悬浮液密度进行调节，悬浮液黏度不测不控，入料压力采取定值控制，影响产品质量稳定，因此对重介质旋流器选煤过程关键参数的多变量控制研究十分必要。

以石圪台、大柳塔和柠条塔选煤厂洗选工艺为基础，本文通过对重介质旋流器选煤工艺流程分析，将旋流器选煤多参量的控制分为两部分。悬浮液性质相关参数控制：通过清水阀、加介阀和分流阀开度变化下对各参量的影响分析，本文采用机理建模法，建立密度、液位和固体体积浓度的控制模型结构，并通过现场实际数据对传递函数模型进行辨识得到具体系统控制模型。对系统采取前馈补偿解耦控制和模型预测控制研究，对比两种仿真结果，模型预测控制在调节时间和最大动态偏差方面控制效果更好。入料压力控制：采取灰分-压力串级控制对产品灰分进行调节，仿真结果表明，利用变频混料泵控制旋流器入料压力具有快速性和较高控制精度的优点，有效弥补了悬浮液密度、悬浮液黏度控制过程中存在较大滞后、调控过程缓慢的不足，提高了产品质量的控制精度。

本文对重介质旋流器选煤多参量的控制研究，在仿真上实现了对重介质悬浮液密度、黏度和入料压力的有效控制及灰分的调节，对解决选煤厂自动化水平低、参数控制单一的问题，以及提高重介质选煤产品质量、末煤回收率、生产效率和经济效益具有一定的理论意义。

The dense medium cyclone has become the most widely used method for coal separation because of its wide particle size range and high separation efficiency. The control accuracy of the process parameters such as suspension the density, suspension viscosity and feed pressure of the dense medium suspension directly affects coal preparation effect. At present, coal preparation plants usually only adjust the density of dense medium suspension, the viscosity of the suspension is not measured and not controlled, and the feed pressure is controlled by a fixed value, which will affect the stability of product quality. Therefore, it is necessary to study the control of key parameters in the coal preparation process of the dense medium cyclone.

Based on the coal preparation process of Shigetai, Daliuta and Ningtiaota Coal Preparation Plants, this paper divided the control of multiple parameters of cyclone coal preparation into two parts through the analysis of coal preparation process of dense medium cyclone. Control of related parameters of suspension properties: through the analysis of the influence of various parameters on the opening of the clean water valve, mediator valve and diverter valve, this paper used mechanism modeling to establish the control model structure of density, liquid level and solid volume concentration. And the transfer function model was used for parameter identification to obtain the specific system control model. The feedforward compensation decoupling control and model predictive control were adopted for the system. Comparing the two experimental results, the model predictive control had better control effect in terms of adjustment time and maximum dynamic deviation. Feeding pressure control: this article adopted ash-pressure cascade control to adjust product ash. The simulation results show that the use of variable frequency mixing pump to control the feed pressure of the cyclone has the advantages of rapidity and high control accuracy, which effectively makes up for the shortcomings of large lag and slow control process in the control of suspension density and suspension viscosity, improve the control accuracy of product quality.

This paper studies the coordinated control of multiple parameters of coal preparation in dense medium cyclone, which effectively adjusts the suspension density, viscosity and feed pressure of dense medium suspension, and solves the problems of low automation level and single parameter control in coal preparation plants, and it is of great significance to improve the quality of dense medium coal preparation products, recovery rate of final coal, production efficiency and economic benefits.