Design And Realization Of ASU Control System

Oxygen, nitrogen and argon play an important role in iron and steel production. A mass of oxygen is needed in blast furnace running, and as the protect gas of steel production, nitrogen is always associated with the steel quality. At the same time, argon is usually used in some special metal production.Oxygen, nitrogen and argon are usually produced by air separated unit (ASU). With the steps of Baosteel's construction and development, the ASUs are becoming gradually one big system, which brings forth to Baosteel Oxygen-Plant more and more critical system requirements on ASUs control.Baosteel branch company (Baosteel for short) has the biggest group of Air-Separation-Units (ASU) in Asia, including 3 sets of big ones above 60kNm3 oxygen an hour. The outputs of these units add up to 300kNm3/h oxygen, 358kNm3/h nitrogen and 10kNm3/h argon. According to Baosteel's stratagem, the existing units still can not meet the need of development. Another 60kNm3/h oxygen unit is thus becoming necessary. This project discusses the design and its fulfil of the ASU control system according to the Baosteel's new unit.Firstly, based on the discussion of the ASU process diagram and control system, the system structure and its hardwares are introduced in this paper.Secondly, according to the theory of compressor surge, anti-surge control technique is discussed, the anti-surge control system of air compressor is designed and fulfilled.Thirdly, based on the introduction of the Oxygen compressor's control system and its connections and interlock logics to DCS, the system design and its fulfil are stated.Fourthly, the control configuration, monitor displays configuration, historic data-base sampling and category configuration technique are demonstrated in detail.Fifthly, the technology involved ASU safety and pipe net steady operation is also introduced in this paper from the system point of view.In the design of this article, anti surge control technology is researched primarily, and is applied in air compressor, oxygen compressor and nitrogen compressor successfully. And the speedy reaction about the pivotal part of oxygen compressor control is realized. At the same time, the friendly interface is realized. The design meet the require of ASU finally.