Corrosion Test And Research For Lay-up Of Supercritical Unit In Fossil Fuel Power Plant

The ultimate goal of this project is to help the supercritical thermal powerenterprise to obtain the optimal way of unit. With the adjustment of China’s powerindustry and the development of power structure,600MW level fossil fuel power unithas become the development direction of China’s thermal power and will soonbecome the main unit of the power grid, especially supercritical parameters units, dueto its lower operating cost and high efficiency, making this type of unit in the currentelectricity market more competitive. Corrosion protection during thermal equipmentoutage is very important work because corrosion during the outage much more seriousthan of during operation. At present, the most used and the best effect method ofsupercritical unit lay-up corrosion protection is octadecylamine film-formingammonia method. However, the present study about octadecylamine main stay in thestudy of subcritical unit, there is no relevant experiments specifically for supercriticalunit, there is no standard detail too. Mainly because there is a big drawback of thismethod, namely octadecylamine protective agent in the unit would pollution exchangeresin in condensate polishing system after restart the unit，make resin failure，whichwould affects water and steam quality, seriously will affect the normal operation ofthe unit. This drawback limits the widespread use of anti-corrosion technologyoctadecylamine in supercritical unit. This paper on the further study of influence andprevent methods of octadecylamine anti-corrosion to ion exchange resin through theoctadecylamine protection combined with the characteristics of supercritical unit inhigh temperature and high pressure experiment platform.First of all, this paper carried out water and steam system thermal equipment filmforming simulation test, find the best concentration of film forming, under theconcentration of further carried out octadecylamine film-forming and desorption testin the simulate actual situation, and analyze the desorption solution, trying to find outoctadecylamine migration form and exist state under the condition of hightemperature and high pressure form. Further tests which octadecylamine protectivefilm desorption contaminates ion exchange resin were carried out, studied pollutingimpact of desorption solution to ion exchange resin.This paper attempts to find a way through test prevent the ion exchange resinfrom octadecylamine protective membrane desorption liquid pollution.Tthis paper tried to carry out recovery test of resin contaminated with octadecylamine, the resultsshow that the resin polluted by octadecylamine almost no recovery ability. Throughstudy the pollution mechanism of ion exchange resin from desorption solution, triedto carry out octadecylamine desorption liquid adsorption experiment by using wasteresin, and further puts forward the pre-closure method to prevent mixed bed ionexchange resin in the condensate polishing system of pollution. Experiment showsthat the ion exchange device in condensate polishing system has series of packingwaste resin pre-closure device can effectively intercept polluting substances of mixedbed ion exchange resin in condensate polishing system, thereby has been preventingpollution of mixed bed ion exchange resin from desorption solution. The method byreusing the waste resin has solved the unit during lay-up octadecylamine corrosionprotection influence the condensate polishing system problem, has the characteristicsof convenient, efficient, cheap, opened up a new way about solving the pollution ofion exchange resin by octadecylamine protective film desorption solution, and for thewidespread use of octadecylamine film-forming protection creates the conditions. Incomplete optimization of octadecylamine anti-corrosion method, at the same timemade indirectly reduce fuel consumption and achieve maximum economic benefits.