Research And Application Of Advanced Control And Optimization For Small-scale Ammonia Synthesis Plant

As the major important industry and the one of large energy consumption in the field of chemical engineering industry, the research on the advanced control and optimization of the production of synthetic ammonia will be the focus in the future years. But in China, especially in the field of small-scale nitrogen fertilizer, although the desire for production optimization is increasingly stronger, nothing effective for this is done because of its complicated conditions and special flows. This dissertation is just focusing on this topic. Based on the actual production process, we combine the optimization theory and the real situation in process industry. Through the study and exploration on "Advanced Control and Optimization for the Small-Scale Ammonia Synthesis Plant", the on-line operating optimization was completed successfully for the first time. And it is the solid foundation of the future work in this field.Because of the special working conditions and the characters of the equipments, the synthetic ammonia production in small-scale plants has the following problems: "Difference of the raw material and the equipments"," Miscellaneity of the influencing factors"," Time-variation for the production system","Frequent fault of the equipment". For these problems we have taken the investigation on the advanced control and optimization in this field. The results show that the overseas advanced technologies can not be applied to domestic system because of the above reasons. And the most domestic research about this is based on simulation; it can't work stably and last longtime. In brief, we found that there are 5 problems as choke point in this field: 1.Lacking maneuverability; 2.Not working stably and for a long time; 3.Bad robust performance; 4.Low precision of the control of the key factor; 5.Problems of the communication.The major work is focusing on the above problems. By analyzing the complicacy of synthetic ammonia in details, we take a deeply study on the process flow and principle of the synthetic ammonia. At last the on-line optimization of the ammonia synthesis system is realized for the first time. The following is the major work and innovation:1. It is the first time to realize on-line optimization of ammonia synthesis in the field of domestic small-scale nitrogen fertilizer successfully. The actual results show...