The Control Optimization Research In Oxygen Making Production

There is large gap between the research on our process comprehensive technology and foreign advanced technology that mainly represented by the short on technology depth, application base research, related field technology borrowing, systematic level, integrated ability, product level and industry ability and so on. In oxygen making industry, there are no problem that can effect the production quota because of the hardware, since large oxygenerator unit is inward or the main compression system is inward. Contrast to the foreign advanced technology, there is large distance on main production quota still. Take Jinan Gas Company Limited for example, the process of its six oxygenerator belong to international advanced process technology, but its stability on production technology ,product quality and its energy cost lag behind the international technology for a rather large gap. The reason is many-sided which include control level and operator's disposition etc. but the main fact is the gap on control level that cause the low intelligent level, high mishandling and normal production's departure from optimization. In short, it is very important actual mean that optimize the oxygen-maiking's control.Control optimization include some preliminary research on air compressor 's anti-surge + pressure(flow) control, molecular sieve switching, upper tower liquid nitrogen valve control, automatic oxygen compressor, automatic load changing. These control system are main system that can affect the production pointer and the equipment's operational reliability. The main content of this topic is to provide improved method through the analysis on frequent used domestic control strategy.Oxygen-making demand high gas flow stability, not the material air that coming into tower or the product gas, if the flow or the pressure fluctuate out some range, the work condition will disorder and the quota will fall down, the energy cost will go up. So, one principle of the oxygen-making control optimization is to stabilize the air pressure and flow. The control optimization about air compressor and molecular sieve switching go surround this principle. There are many facts that can affect upper tower liquid nitrogen valve's control and it's difficult to divide focus, so air separation plant doesn't use automatic control in our country. We use combined control to realize automation through profound theory analysis and explore on the key effect fact and amplitude limit of valve's action.Oxygen compressor full automaticity and automatic load changing belong to system engineering and they realize full automaticity by deep research on process and considering the safety and economic of the production and borrow ideas from foreign related control idea by the mean time.The control system use Japanese HENGHE CS3000 DCS control system and it has the character of reliable hardware and convenient program configuration and easy to realize its control idea.