Automatic pressure stabilizing control device for steam of methanol distillation system and control method of control device

Abstract

The invention relates to an automatic pressure stabilizing control device for steam of a methanol distillation system and a control method of the control device. The device comprises a methanol distillation pipeline, a steam work pipeline and a microcomputer control system, wherein the methanol distillation pipeline comprises a crude methanol pipeline which is connected with an inlet in the upper part of a pre-distillation tower through a crude methanol feeding adjustment valve; the steam work pipeline comprises a middle-pressure steam pipeline and a low-pressure steam pipeline; the microcomputer control system comprises a model predictive controller; the model predictive controller is connected with a DCS (data communication system) master control clip. The control method comprises a control method for the pressure of a steam buffer tank, a control method for the liquid level of a reflux tank of a pre-distillation tower, a control method for the temperature at the bottom of the pre-distillation tower, a control method for the liquid level of the pre-distillation tower, a control method for the temperature at the top of an atmospheric tower, a control method for the temperature at the bottom of the atmospheric tower, a control method for the temperature at the top of the pressurizing tower and the temperature at the bottom of the pressurizing tower, a control method for the reflux ratio of the atmospheric tower, and a control method for the reflux ratio of the pressurizing tower. The device and the method have the advantages of timely adjusting a device load and reducing the steam consumption.

Description

technical field [0001] The invention belongs to the technical field of steam automatic pressure stabilization, and in particular relates to a steam automatic pressure stabilization control device for a methanol rectification system and a control method thereof. Background technique [0002] In nitrogen fertilization systems, it is common to use excess heat from the system for by-product production. The methanol rectification system uses the low-quality steam from the thermal power plant to carry out the rectification process. However, due to the use of waste heat in the system, the low-pressure steam has insufficient heat value, and a certain amount of medium-pressure steam needs to be distributed. But only using medium-pressure steam is a great waste of low-pressure steam. At the same time, during the use of steam, the two streams of steam will affect the rectification device due to load fluctuations in the upper section, resulting in sharp changes in the temperature of ea...

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Problems solved by technology

The methanol rectification system uses the low-quality steam from the thermal power plant to carry out the rectification process. However, due to the use of waste heat in the system, the low-pressure steam has insufficient calorific value, and a certain amount of medium-pressure steam needs to be distributed.

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