Research On The Thermal Deviation Of The Two Kinds Of Supercritical Boilers

The article is focus on the research of two supercritical boiler furnacethermal deviation analysis. A numerical modeling was built on a four-walltangentially fired boiler. The reasons for the formation of the flue gas sideheat deviation in this furnace boiler was studied, so the optimized designprinciple of the thermal deviation between the screen in the boiler wasachieved. By adjusting screen flow deviation, the flue gas side thermaldeviation and flow deviation was able to match, finally the purpose ofscreen thermal deviation balance was achieved. The principle wasappropriate for opposed wall boiler. On the basis of the principle, the hightemperature superheater and reheater of the four-wall tangentially firedboiler were analyzed in this paper, and so were the low temperature reheaterand high temperature reheater of the opposed wall boiler, two relevantoptimized design programs were proposed. By contrasting the degree thatthe flow deviation curve and the flue gas side heat deviation curve matches，the results were studied，the most optimized design program was achieved,the purpose is to make superheater and reheater tubing heated evenly,andalso reduces the possibility of pipe over-temperature. The specificconclusions are as follows:1、In this paper, the fluent software was used to make hot numericalsimulation for BMCR conditions in the four-wall tangentially firedboiler,the characteristics of the flue gas speed and temperature in the furnacewere achieved. The result can explain the reason for the existence of the fluegas side heat deviation in the four-wall tangentially fired boiler,while theresult of opposed wall boiler was compared with reference. Finally, aconlusion was achieved: the reason for the existence of the flue gas side heat deviation is caused by the unique combustion mode of different furnace, andthe characteristics of the deviation is inherent.2、According to the reason for the existence of the flue gas side heatdeviation, the boiler thermal deviation optimization principle was proposed,high temperature superheater and reheater of four-wall tangentially firedboiler were also optimized designed, two optimization programs of addingthrottling circle and change the inner diameter of the collection box wereproposed.3、Acorrding to the boiler thermal deviation optimization principle,thelow temperature reheater and the high temperature reheater of opposed wallboiler were optimized designed, two optimization programs of reducing theheating surface of the low temperature reheater and adding throttle lap wereproposed.