The Controlling Research On Dew Point Corrosion At The Top System Of The Atmospheric Tower

Owing to the particularity of petrochemical industry, fire and explosion accidents are veryeasily happened. In most parts of the types of disasters and accidents, which are caused bycorrosion leakage. The atmospheric tower is not only the leading device of petrochemicalenterprises, but also it is one of the most serious devices in the refinery. It’s corrosion can bedivided into the high-temperature naphthenic acid corrosion and the low-temperature dewpoint corrosion. The part of the low-temperature corrosion are mainly concentrated in the topof the atmospheric tower and the condensate system. Corrosion of condensation system areconsiderably widespread and noticeably serious.The main corrosion effect factors of the low-temperature dew point corrosion in theatmospheric tower system are mainly about chloridion, temperature and pH value throughon-the-spot investigation. We could make the test solution according to the actual situation ofthe each factor. The test is designed by the orthogonal experiment method, and the each testincludes three effect factors, meanwhile each factors have two levels. In order to obtain thepolarization curves and the corrosion rate, we can use the electrochemical polarization in theexperimental study. According to the initial conditions and the boundary conditions throughon-the-spot investigation, the use of computational fluid dynamics software Fluent tonumerically simulate. According to the element model and the three-dimension object model,use the Hex/Wedge grid to divide the geometrical model into the mesh generation, standardk-epsilon calculation model is applied and the near wall region was modeled by using the wallfunction approach, and assuming that the fluid is in the steady flow. We can obtain thedistribution of the velocity field, the temperature field and the pressure field by simulation.In order to determine the tower system of dew point corrosion control methods, weshould think about the research of the corrosion testing and the numerical simulation research.For one thing, we could design the bypass pipe to replace the broken elbow-six. For anotherthing, we may set up the corrosion online monitoring devices which are installed the elbow-sixboth before and after. So that we can effectively slow down the corrosion rate of atmospherictower cooling system.