High pressure boiler tube removal depth has a effect on the results unsaturated resin; chloride, unsaturated polyester resin, a high degree of stability, excellent oxidation resistance and high-temperature acid-oxidizing media such as wet chlorine, chlorine solutions outstanding resistance to media and heat resistance, higher in order under pressure to use, often regarded heating surface tube design is very thick.
In the low and medium pressure boiler tubes using the process, we also encountered many problems, according to indicators of qualified production, improved production methods, but its life issues than expected or to too few. Our dedicated technical staff summed up in recent years in low and medium pressure boiler pipe temperature corrosion research situation. By fired boiler with high sulfur anthracite occurs after severe high temperature corrosion. Analysis of water wall tubes at high temperature corrosion conditions, at a higher temperature reducing atmosphere chlorine sulfur corrosion and high temperature corrosion mechanisms of corrosion and corrosion main causes, combined with the use of low sulfur coal than Yangquan Datong bituminous coal actual situation, the combustion system transformation. High pressure boiler tube clear the depth does not exceed the nominal wall thickness of negative deviation, its cleanup at the actual wall thickness of not less than the minimum allowed. Prevent high-pressure boiler in the fire rapidly warming deformation slump, its measures are varied, the key is to take a different approach depending on the circumstances, such as adiabatic, refractory steel barrier direct flame burning, reduce the heat transfer rate delayed steel temperature, strength becomes weak time. But no matter what method, the principle is the same. Fire-resistant coating is a fire in recent years more advanced technical measures. Since impurities quality of high-pressure boiler, high level of harmful elements in steel products and the control of inclusions are very strict requirements, to try all kinds of impurity elements are required to control in a very low level, often in the production refining the production process used to protect its cleanliness. Boiler heating surface tubes in the operation of the cooling conditions deteriorate, dry, so that a sudden increase in wall temperature short term, the temperature reaches a critical point (Ac1) above, the tensile strength of high-pressure boiler tubes sharp decline in pipe stress exceeds the yield limit, resulting in shear fracture and burst pipes, burst pipes called this short overtemperature squib. Material adverse squib means misuse or use of the defective steel steel tubes caused early damage. In unit installation construction, since the presence of supercritical unit installation system complexity, many kinds of welding consumables, installation difficulty, high quality requirements characteristics.
First, high-pressure boiler pipe installation is difficult, especially in Supercritical no drum, increasing the starting system, heating pipe systems, rigid beam than conventional subcritical boilers large volume, quantity, and all with the heating surface welding, installation difficult. High-pressure boiler tubes often used in high temperature and pressure conditions, gas and water vapor at high temperature tube under the effect of oxidation and corrosion occurs.
