The intensity of boiler wall thickness should be strengthened

Steam stimulation is a mature technology that is commonly used to improve the development of heavy oil. Its main equipment is a wet steam generator. The macro-inspection, chemical composition analysis and metallographic analysis of the furnace tubes damaged by injection of steam generators (also called steam injection boilers) for oil injection in oil fields were analyzed, and the causes of scale formation were analyzed. The tubes of wet steam generators were examined at work. Scale and corrosion mechanisms under conditions. The results of the inspection and analysis show that the boiler is in a state of strong overheating for a short period of time, which is the direct cause of the damage of the boiler tube. The influence of fouling and water quality is one of the reasons for the occurrence of tube burst.

Assume that the steam pressure at the outlet of the boiler is 14MPa, and its corresponding temperature is 337°C. According to the boiler manual and related heat transfer manual, the temperature of the outer wall of the furnace tube is TWB1=337+23.94=360.94°C, which is lower than the allowable operating temperature of the material; When the tube fouling ≥ 1mm, the outer tube wall temperature TWB2 = 337 + 263.93 = 600.93 °C, which is 240 °C higher than the wall temperature without scaling, and the local temperature far exceeds the temperature that the tube can withstand. The boiler pressure at this time far exceeds the allowable stress of the pipe and inevitably a pipe explosion accident will occur.

The monitoring of boiler wall thickness should be strengthened, and problems such as fouling and corrosion of furnace tubes must be discovered in a timely manner. At the same time, the dynamic alarm technology of boilers should be actively studied to effectively prevent the occurrence of overheating problems. In addition, the chlorine ion content in boiler feed water should be strictly controlled according to the standard. .