When the steam pressure is too high, the safety valve will not operate in case of failure, and the pressure will be overpressured. In severe cases, a blasting accident may occur. Overpressure can cause excessive mechanical stress on the pressure-bearing components, which will threaten the safe operation of the equipment. The blast will force the steam boiler to be shut down. Portable Cable Reel,Garden Water Hose Reel,Retractable Garden Hose Reel,Wall Mounted Garden Hose Reel NINGBO QIKAI ENVIRONMENTAL TECHNOLOGY CO.,LTD , https://www.water-hose-reel.com
When the safety valve is actuated, a large amount of steam is discharged to cause economic loss. If the safety valve is operated too many times, the high-pressure steam impacts the valve flap to wear the joint surface, which is easy to close after the seat is returned, and the leakage loss is increased. Sometimes the safety valve does not return to the seat and stops the furnace.
When the air pressure is lowered, the steam is reduced in the work of the steam turbine, for example, the steam consumption is increased and the fuel consumption is increased. The data shows that when the steam pressure is reduced by 5% compared to the rated value, the steam consumption of the turbine will increase by 1%. For a direct-steam boiler equipped with a double-sided water-cooled wall, when the steam pressure is lowered too much, the double-sided water-cooled wall outlet working fluid may vaporize, which affects the hydrodynamic stability of the membrane water wall. The range of normal steam pressure fluctuations is ± (0.1~0.2) MPa for high-pressure boilers and ultra-high pressure boilers.
Effect on steam temperature: When the steam pressure rises, the temperature of the superheated steam also rises. This is because when the vapor pressure rises, the saturation temperature increases, and it takes more heat to change from water to steam (the water wall metal also absorbs more heat). Under the condition that the fuel quantity is not changed, the evaporation amount of the boiler is instantaneously reduced (because some steam in the boiler water is condensed), that is, the amount of steam passing through the superheater is reduced, and the attraction amount of the steam is increased, resulting in an increase in the temperature of the superheated steam.
Effect on water level: When the steam pressure is reduced, some of the furnace water evaporates due to the decrease of the saturation temperature, causing the volume of the furnace water to expand, so the water level should rise. Conversely, when the vapor pressure rises, some of the steam in the furnace water will condense due to the increase of the saturation temperature, causing the volume of the furnace water to shrink, so the water level will decrease. If the change in vapor pressure is caused by a load change, the above-described change in water level is a temporary phenomenon, and then it is changed in the opposite direction. If the judgment is wrong, improper adjustment is easy to occur.