Daily question (December 22)
Thread Content
For steam drum boilers, why does the superheated steam temperature decrease when the feed water temperature increases?
The feed water temperature of the boiler drops, 1. Regardless of the load: The heat required for heating and evaporation of the working fluid increases, the furnace temperature decreases, the ignition point of pulverized coal is delayed, and the flame center moves upward. When the amount of fuel remains unchanged, the evaporation capacity of the boiler decreases, causing the superheated steam temperature to increase. 2. The load remains unchanged: If you want to maintain the evaporation capacity, you must increase the fuel, so the smoke exhaust volume will increase, the convection heat absorption will increase, so the steam temperature will increase.
Regardless of the load, the heat required for heating and evaporation of the working fluid decreases. When the fuel remains unchanged, the evaporation capacity of the boiler increases. This causes the superheated steam temperature to decrease.
If the load of the boiler remains unchanged and the feed water temperature increases, fuel consumption will inevitably be reduced and the furnace temperature will drop! The amount of smoke will also be reduced accordingly! As the temperature and pressure decrease, the amount of flue gas decreases, and the heat absorbed by the superheater decreases, which will inevitably lead to a decrease in temperature. If the load increases, the amount of steam that needs to be heated also increases, and the relative temperature also decreases!
For steam drum boilers, why does the superheated steam temperature decrease when the feed water temperature increases? answer: For steam drum boilers, the feed water temperature increases, which reduces the heat absorption of the feed water in the water-cooled wall. When the amount of fuel remains unchanged, the steam production of the boiler increases, and the relative heat absorption of the steam will decrease, resulting in a decrease in steam temperature. ； If the evaporation capacity of the boiler is kept unchanged, the amount of fuel must be reduced accordingly, which will weaken the combustion, reduce the amount of flue gas, and also reduce the steam temperature.
The feed water temperature of the boiler rises, 1. Regardless of the load: The heat required for heating and evaporation of the working fluid decreases. When the amount of fuel remains unchanged, the evaporation volume of the boiler increases, causing the superheated steam temperature to decrease. 2. The load remains unchanged: If the evaporation rate is to be maintained, the fuel must be reduced, which not only reduces the temperature of the entire furnace, but also reduces the temperature of the furnace outlet smoke. The amount and flow rate of flue gas flowing through the superheater and reheater are reduced, the boiler heat load is reduced, the tube wall temperature is reduced, and the superheated steam temperature naturally decreases.
As the feed water temperature rises, while keeping the evaporation volume constant, the combustion intensity of the furnace must be reduced, resulting in a decrease in the amount of flue gas at the tail. If the steam volume remains unchanged, the steam temperature will decrease!
answer: For steam drum boilers, the feed water temperature increases, which reduces the heat absorption of the feed water in the water-cooled wall. When the amount of fuel remains unchanged, the steam production of the boiler increases, and the relative heat absorption of the steam will decrease, resulting in a decrease in steam temperature. ； If the evaporation capacity of the boiler is kept unchanged, the amount of fuel must be reduced accordingly, which will weaken the combustion, reduce the amount of flue gas, and also reduce the steam temperature.
For steam drum boilers, the feed water temperature increases, which reduces the heat absorption of the feed water in the water-cooled wall. When the amount of fuel remains unchanged, the steam production of the boiler increases, and the relative heat absorption of the steam will decrease, resulting in a decrease in steam temperature. ； If the evaporation capacity of the boiler is kept unchanged, the amount of fuel must be reduced accordingly, which will weaken the combustion, reduce the amount of flue gas, and also reduce the steam temperature.
1. For steam drum boilers, the temperature of the feed water increases, which reduces the heat absorption of the feed water in the water-cooled wall. When the amount of fuel remains unchanged, the steam production of the boiler increases, and the relative heat absorption of the steam will decrease, resulting in a decrease in steam temperature. ； 2. If the evaporation capacity of the boiler is kept unchanged, the amount of fuel must be reduced accordingly, which will weaken the combustion, reduce the amount of flue gas, and also reduce the steam temperature.
As the feed water temperature of the boiler increases, the heat required for heating and evaporation of the working medium decreases. The furnace temperature increases, and the evaporation capacity of the boiler increases, causing the superheated steam temperature to decrease.