Other technical advantages of boiler

Other technical advantages of boiler

 

1. Oxygen-enriched combustion of pulverized coal furnace, in order to control the combustion temperature in the furnace, a large amount of flue gas is required for recirculation (70-80%).

 

2. Because the circulating fluidized bed contains a large amount of solid particles in the recirculated flue gas, it can control the furnace temperature very effectively, thereby greatly reducing its manufacturing and operating costs; (in the 210MWeCFB oxygen-enriched combustion mode, the boiler island The volume is about half of that in air combustion mode).

 

3. Other technical advantages that can be combined into circulating fluidized bed;

 

4. It can effectively remove SOx at the same time;

How does the boiler reduce the emission of nitrogen oxides through the air volume

 

Oxygen-deficient combustion is followed by oxygen-enriched combustion.

 

It should be known that nitrogen oxides are generated at high temperatures. When the combustion temperature is greater than 800°C, the formation rate of nitrogen oxides is the highest, and when the combustion temperature is lower than 600°C, the formation of nitrogen oxides is minimal.

 

If a large amount of blowing is used to increase the excess air to reduce the combustion temperature, a large amount of heat energy will be taken away by the air. If oxygen-enriched air is used, that is, the technology of increasing the oxygen content to reduce the blowing volume and the energy consumption required for oxygen production It will be very high.

The production of nitrogen oxides in the boiler is mainly to control the temperature

 

As long as the furnace temperature is controlled below 850 degrees, it is guaranteed to meet the standard. It is also possible to spray urea or ammonia water to the high temperature zone to decompose.

The amount of boiler nitrogen and oxygen reacting at high temperatures mainly depends on the combustion temperature, nitrogen concentration and oxygen concentration

 

The higher the temperature and the greater the concentration, the more nitrogen oxides are produced. However, there is no theoretical formula or empirical formula for the specific calculation method, and it can only be controlled from the trend. Most boilers reduce the flame temperature in the combustion zone and reduce the air supply in the high-temperature zone, so that the combustion reaction in the high-temperature zone is in an oxygen-deficient state, resulting in incomplete combustion. The flue gas goes to the low-temperature zone and then burns with the secondary air to make other substances burn completely. , To achieve the goal of reducing nitrogen oxide emissions.

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