Boiler operation accident case-1
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This post was last edited by the wise man at 2016-12-8 21:04. Jinzhou Power Plant No. 3 Boiler Safety Valve Calibration Boost and Real Jump Caused the Pipe Blasting Accident Outside the Boiler.: On July 9, 1999, during the thermal adjustment process of the safety door of Boiler No. 3, the straight pipe section from the economizer outlet header in the high-temperature section to the steam drum contact pipe exploded, causing five deaths and three serious burns. Accident cause analysis: The accident occurred due to the existence of longitudinal cracks on the outer wall side of the steel pipe in this section, resulting in the effective wall thickness of the steel pipe being only about 1.7mm. This resulted in an instantaneous overload fracture and explosion when the main steam pressure reached 16.66MPa during the setting process of the safety door of the No. 3 boiler. The actual working stress of the effective wall thickness of the steel pipe reached the tensile strength of the material.
Accident summary: 1. The safety valve of the boiler pressure vessel is calibrated by increasing the pressure and jumping, which will cause the steam pressure of the boiler pipe to be overpressured, resulting in a reduction in the life of the boiler pipe and easily causing the boiler and the pipes outside the furnace to explode, with serious consequences. ； 2. The safety valve of the boiler pressure vessel is calibrated by boosting the pressure and jumping, which will cause noise pollution. The safety valve will jump frequently, which will cause damage to the sealing surface. ； 3. Purely mechanical spring safety valves and disc spring safety valves can be calibrated and adjusted using the safety valve online constant pressure instrument. Calibration and adjustment can be performed during unit startup or load operation (generally at 60% to 80% rated pressure).
The accident summary did not mention the crack in the steel pipe?