XRD analysis conclusions may be drawn as follows:
1. There are many a crust or safety deposit attached to the outer wall of a pipe at the side of which do not undergo to erosion.
2. A kind of a compound found on crust could have come from some fly ash.
Mechanic and Thermal Analysis.
From internal condition of pipe operational can be seen high burden work experienced by those pipes both in thermal and pressure from internal side of pipe. The outer side of pipe also get heat from flue gas derived from furnace.
In addition to internal and external pipe there that other instrument which pipe work on this namely soot blower. Placement soot blower is on either side that dealt and work alternately per each side, where both sides named side A and B (side see picture 2.14).
Soot blower side A and B side of the information, having long range unequal. So if run simultaneously likely to conflict, because one side overlapping against the other side. This effect risk deflection soot blower due to hot temperature high on regional operation also different. It is risky because could cause process cleaning is not work well.
Simulation support.
Based on mechanical and thermal analysis have been described previously, it will be simulated some cases variations in thinning of the walls to the investigated its effects on strength of the pipe during boiler operation as presented in Table 2.8 with thickly thinning of assumes that occur across the surface of the pipe.
Based on the operating conditions, the pipe of secondary super-heater (SSH) is located at the crossing of very hot gas that is on top of the combustion chamber and the heat radiation is received directly from the combustion chamber. Thermal-structural simulation was performed to determine the influence of high temperature (either due to radiation from gas combustion as well as results from the temperature of the steam itself), and high pressure steam in the pipe of voltage distribution pipeline that occur for a wide variety of wall thickness.
Data input simulation.
Geometry for modeling, material properties, boundary conditions, and used for the purposes of computer simulation presented in table 2.1-2.3 on Boiler Tube Research (super-heater) part 1.
Simulation result.
Simulation result of the maximum von Mises strength is presented in Table 2.9 and Figure 2.15. Based on this table, the conclusion that if the thinning of the wall thickness occurs up to 30%, the increase in von Mises strength until 58%. This means that if the thermal load and pressure caused by the heat from the fluid in pipes and thermal loads by the burning gas from outside the pipe occurs continuously, then the power of the pipeline to withstand the loads will also be getting down.
Pipe also a very vulnerable experiencing plastic deformation caused by depletion wall toward to maximum von mises strength to melt strength minimum material required.
Based on tables 2.10, depletion walls of 30 % will cause a decrease in the power to withstand plastic deformation 12 %. If linked with cases occurring on pipe 2, then, if any solid particles ( e.g. fly ash ) or other fluid that impacted pipe outside like when soot blower operated, then pipe will be very easily got plastic deformation, afterward subjected to wear, an abrasive and finally there are parts material a pipe gradually crushed and missing due to erosion. Pipe will be evermore thin and faster fail.
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