Design And Simulation Of Catalytic Regeneration System For Marine SCR

With the continuous development of international shipping industry and ocean shipping, the exhaust emissions from marine engine fuel has become a major source of pollution in coastal areas especially the port, governments and international organizations have made the ship diesel engine NOx emission limits of related laws and regulations. The International Maritime Organization formulated the"MARPOL73/78 Convention" in Annex VI to the imminent implementation of the he third stage (Tier III standard)more stringent emission limits.In a lot of NOx control technology, Selective Catalytic Reduction (referred to as SCR) post-processing technology is recognized as the most effective to reduce marine diesel engine NOx emissions. Catalytic reactor is the core of the system of SCR system device, which provided a place to react catalytic reduction reaction on the surface of the catalyst. How to prolong the service life of catalyst used, to ensure its catalytic properties, and SCR system running cost and system running effect has a direct relationship. Based on marine diesel engine as the research object, research and design a kind of SCR catalysts structure, specific work content is as follows:(1)Through the analysed and introduced the principle of the SCR catalytic reaction, put forward reasonable design scheme of the catalytic reactor, this paper mainly consider reducing emissions of NOx and solid particles, and prolong the service life of catalyst effectively, prevent carbon which from exhaust smoke attached in catalyst and lead to "poisoning", choose ceramic materials as catalyst support material, using the ejector principle blow ceramic catalyst carrier;(2) Use the FLUENT simulation software, establish the model, The diameter of the mixing chamber, the diameter of nozzle, the distance from nozzle to the entrance of the ejector was analysed, and analysis to get the best ejector device structure. Combined the injector and the ceramic carrier material, use porous media model, to blow the whole process of the simulation analysis, design reasonable catalytic reactor unit finally;(3) Designed the overall structure of the reactor, put forward the reasonable reverse blowing scheme, to reduce the impact of the normal operation of the diesel engine in the reverse blowing process. Designed the control circuit of the reverse blowing, and further simulation of the circuit, and prove the feasibility of the control circuit, completed catalytic reactor design in SCR system.