Beretta Wall-Hung Boiler Maintenance Information; What Are the Factors That Cause Changes in Steam Pressure?
There are two aspects to the factors that cause changes in boiler steam pressure.
(1) External Factors
External factors refer to the increase or decrease of external load and the load during accidents. This is reflected in the change in the amount of steam required by the turbine. When the fuel supply and air volume supplied to the boiler are fixed (stable combustion conditions), then the amount of steam produced is fixed, and the amount of steam supplied to the turbine is also fixed. At this time, the evaporation rate is in balance with the external load. When the evaporation rate of the boiler exactly meets the steam requirement of the turbine, the steam pressure can be maintained stably. When the external load increases, the amount of steam required by the turbine must increase, but the fuel and air supply to the boiler has not changed, at this point the pressure must drop. When the evaporation rate of the boiler is greater than the amount of steam required by the turbine, the steam pressure will rise.
(2) Internal Factors
Internal factors refer to changes in steam pressure caused by variations in the combustion conditions of the boiler when the external load remains unchanged. The stability of steam pressure depends on the stability of the boiler's combustion conditions. When combustion is unstable or poorly coordinated, the thermal intensity in the furnace will change, causing changes in the heat absorption of the evaporative heating surface, which will result in an increase or decrease in the amount of steam produced after heating, thus causing changes in steam pressure. There are many factors that affect unstable combustion and poor coordination, such as changes in coal type, changes in the amount of pulverized coal fed into the furnace, changes in pulverized coal fineness, and improper coordination of air and coal powder, as well as improper ratios of air volume and air velocity, all of which can cause fluctuations in furnace temperature and lead to changes in steam pressure. Faults in the coal feeding, fuel oil, and pulverizing systems can also cause changes in steam pressure.
Whether it is external or internal factors, changes in steam pressure are reflected in the steam flow. Therefore, during the operation of the boiler, the reasons for the changes in steam pressure can be judged based on the changes in steam pressure and steam flow to determine whether they are caused by external factors or internal factors. When the direction of change in steam pressure is opposite to that of steam flow, it belongs to external factors; when the direction of change in steam pressure is the same as that of steam flow, it belongs to internal factors.
Source: Beijing Beretta Wall-Hung Boiler Repair Phone http://blog.sina.com.cn/beileitabigualu.