Study And Application Of The Key-control Technique To The Domestic Large Coal-gas Compressor

For the needs of the development of the cyclic economy, making use of the mixed coke oven gas and blast furnace gas, saveing energy sources, reduceing the coal gas put the pollution of the environment that spread brings, Jinan Iron and Steel Group General Company set up the Gas-steam Combined Cycle Unit generated electricity, to have the economic benefit concurrently with social performance. The coal gas compressor satisfied the burnable coal gas source that pressure temperature request for the gas Turbine is an important link for generating electricity craft process.Since Oct.2004, 8 sets of compressors have already successfully come into use.The interlock protection system and the loop control function are already used. The anti-surge automatic control and the pressure control does not work very well when the flow is low. Because of the great variety of the work condition, the mistake action occurrs in many times. Output pressure is unstable, the reflux is great, so it is not economic, the oil gas shift not successful, because coal gas contains much dust and tars.The coal-gas compressor has to maintain frequently, therefore the whole set of machine has to shutdown, the productivity reduced . According to this situation, the paper seeks a suitable control method to solve the practical problem with various control theory.In this paper, the writer analyzes the control process of coal-gas compressor , finding out the basic problem of the normal production, proceeding various ways and thinkings to get through the problem, doing the reasonable and excellent turning to improve the system.Surge phenomenon is in the instability flow condition when the centrifugal compressor works in little flow and it is very harmful to industrial production. It makes centrifugal compressors performance worse so it must be strictly prohibit against this kind of phenomenon, In this paper by analysis various affects about the stability circulates of the compressors system, establish the anti-surge automatic control mathematics model that be applicable to this machine set. For the characteristics of the machine set, used for the little flow situation, the stabilize district more narrow and cause surge very easily, test the little flow area of the compressor, according to test result proceed conjunction with the expect function line, Looking for the actual anti-surge control line. Based on these methods, perfectly designed and developed the anti-surge automatic control systerm, guaranteeing the safety running and reducing the mistake action to the best, reducing the energy depletion.The coal gas compressor exit pressure contain very multifarious variety,it is difficult to express its characteristic with accurate mathematics model, adjustment of inlet guide vanes can hardly throw in the auto, Make use of the split control and the decoupling control etc various controls method combination, pass the independence development DCS control system application software, obtained the good result with the economic performance in satisfied technique.