Maintaining the normal operation of the boiler is a professional and technical task. Considering that the overall quality of the stove personnel engaged in this work is different, there are some deviations in many knowledge perceptions. Based on years of professional experience, Fangkuai boiler technicians are responsible for steam pressure control during the operation of your popular boiler.

First, the boiler steam pressure allowable fluctuation value.
       The choice of boiler steam pressure depends mainly on the needs of the user. The steam pressure is low, the pressure-bearing components are safe and the energy consumption is also reduced, but the steam quality produced at the same time will be relatively poor and the heat is low. Humidity is difficult to meet the needs of some disinfection, sterilization, breeding, heating and power generation. The steam pressure has high energy consumption, and the corresponding steam equipment, piping and valves are also subjected to high pressure, and the maintenance requirements are also stricter. Heat loss and leakage losses during steam production and transportation will also increase. At the same time, the salt carried by the high-pressure steam increases with the increase of the vapor pressure. These salts may increase the possibility of scaling, overheating, air bubbles, blockage or even bursting of the heated surface of the water wall tube, the smoke pipe, the drum and the like. . The entry of steam salt into the steam turbine will reduce the flow area of ​​the turbine and reduce the internal efficiency, which will seriously affect the heat transfer efficiency.
       Therefore, the furnace personnel must install the specified working vapor pressure for operation, generally allowing the fluctuation of the steam pressure to be 0.05-0.15 MPa.

Second, the basic cause of changes in steam pressure.
       1. External disturbance: The change of steam pressure caused by external load change is called external disturbance, referred to as “external disturbance”. When the external load increases, the steam consumption of the unit increases, and the boiler has not been adjusted to adapt to the new working conditions. The evaporation of the boiler will be less than the external demand for steam, the material balance relationship will be broken, and the steam pressure will drop.
         2. Internal disturbance: due to changes in the working conditions of the boiler itself, the change in steam pressure is called internal disturbance, referred to as "internal disturbance". The amount of steam required by the outside world does not change during operation, and the steam in the evaporation zone is caused by changes in the combustion conditions of the boiler (such as unstable combustion or changes in fuel volume and air volume) and changes in operating conditions (such as heat transfer) in the boiler. The amount of change changes, and the material balance relationship between the boiler evaporation amount and the steam demand is destroyed, so that the steam pressure changes.

Third, the danger of boiler overpressure.
       1. Metal materials have their specific metal material yield strength at a certain temperature. Over-pressure operation will result in thermal fatigue of metal materials. Operation beyond the fatigue limit will result in a decrease in yield strength. Breaking the yield limit will lead to rapid creep. Change until it bursts.
       2. The strength of the metal material can be compensated for by increasing the wall thickness of the metal under certain conditions. The increase in wall thickness increases the temperature difference between the inner and outer walls, and the heat transfer rate decreases. The wall temperature difference will cause the thermal stress of the metal material to increase and aggregate.