Unit control system and method for energy recovery of purified terephthalic acid (PTA) device

Abstract

The invention relates to a unit control system for energy recovery of a purified terephthalic acid (PTA) device. A turbine, a speed reducer, a compressor and an expansion machine are sequentially connected. A first auxiliary system is connected with the turbine, and a second auxiliary system is connected with the compressor and the expansion machine. A control device is connected with the turbine, the compressor, the first auxiliary system and the second auxiliary system. A control method includes the steps that all valves in the first auxiliary system and the second auxiliary system are controlled to be in initial states; the turbine is started to drive the compressor unit to carry out the first time of warming, and the second time of warming is carried out after the rotating speed of the turbine reaches a first set value and is kept for set time; after the rotating speed of the turbine reaches a second set value and is kept for set time, the rotating speed exceeds a critical rotating speed value and then reaches a rated rotating speed; and anti-surge control is carried out in a rated rotating speed stage, all the valves of the second auxiliary system are controlled to be opened or closed, and the turbine is driven to keep the set rotating speed. By means of the control system and the control method, the optimal load regulation and switching are achieved, efficient gradient utilization of energy is achieved, and capacity balance of the whole control system is achieved.

Description

technical field [0001] The invention relates to an energy recovery control system and method for a PTA device in the chemical industry, specifically a computer control system applied to the control of three sets of PTA devices to ensure the control system and method for the entire energy recovery. Background technique [0002] PTA (Purified Terephthalic Acid) is the abbreviation of purified terephthalic acid. Appearance is white crystal or powder at normal temperature, non-toxic, tasteless, mainly used in the production of polyester (PET), polyester fibers can be obtained by spinning polyester fibers accounting for 70% of chemical synthetic fibers, PTA is the main raw material for the production of polyester fibers , Widely used in chemical fiber, light industry, electronics, construction and other fields. Not only are polyester materials used more and more in food packaging, but also in non-food packaging such as medicine and cosmetics, as well as in industries such as PBT...

AI Technical Summary

Problems solved by technology

The by-product steam generated by the oxidation reaction heat is recovered by the steam turbine. The existing control system cannot guarantee the maximum efficiency of the unit. When the unit is in normal operation, all the anti-surge valves of the control system are closed. In case of process fluctuations, etc., the anti-surge The vibration valve will open quickly

No, the anti-surge valve cannot be closed all the time, resulting in a part of energy loss

In addition, the control of the PTA control system is complex, requiring a large number of personnel to operate when driving, and the start-up time is long, and the response time of the control system is long, requiring a high configuration of the control system.

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