控制锅炉燃烧工况也是降低粉尘氮氧化物和二氧化硫排放的一种方法。当空气进入炉膛当中时降低过量空气的含氧量在一定程度上会起到限制区内氧浓度的上升。因而减少氧和硫，氧和氮气的氧化反应，从而减少二氧化硫和氮化物的生成速度。但是过度控制氧量，一氧化碳会增加，对锅炉燃烧有影响，从而影响锅炉效率。还是要适当控制氧量，氧量越低二氧化硫和氮氧化物的排放量就越少；床温也是影响二氧化硫和氮氧化物排放量的一个主要因素。每台炉的工况都不一样，我们运行的六#炉根据实践总结，氧量控制到百分之三到四，床温在850到950之间较科学，粉尘、氮氧化物、二氧化硫的排放比较低，而且不影响锅炉效率（一般情况下，床温保持在950左右是蕞佳状态）。总体来说在锅炉负荷稳定的情况下，控制锅炉工况对脱硫脱硝控制是有帮助的。如果锅炉负荷不稳定的情况下，氮化物和二氧化硫的排放量过多还是用氨水直投方法较快。
Controlling boiler combustion conditions is also a method to reduce the emission of dust nitrogen oxides and sulfur dioxide. When the air enters the furnace, reducing the oxygen content of excess air will increase the oxygen concentration in the restricted zone to a certain extent. Thus, the oxidation reaction of oxygen and sulfur, oxygen and nitrogen is reduced, so as to reduce the generation rate of sulfur dioxide and nitrides. However, if oxygen content is over controlled, carbon monoxide will increase, which will affect boiler combustion and boiler efficiency. The lower the oxygen content, the less sulfur dioxide and nitrogen oxide emissions; Bed temperature is also a major factor affecting SO2 and NOx emissions. The operating conditions of each boiler are different. According to the practice summary of the six \n\e boilers we operate, the oxygen content is controlled to 3-4%, the bed temperature is scientific between 850 and 950, the emission of dust, nitrogen oxide and sulfur dioxide is relatively low, and does not affect the boiler efficiency (generally, the bed temperature is kept at about 950). Generally speaking, under the condition of stable boiler load, controlling boiler working conditions is helpful for desulfurization and denitration control. If the boiler load is unstable and the emission of nitrogen compounds and sulfur dioxide is excessive, it is faster to use the method of direct ammonia injection.
脱硝入口氮氧化物变化大与燃烧调整煤质变化，氧量，一次风量，二次风量的控制有很大关系。脱硝平台设立在旋风分离器的入口处，脱硝反应区的入口到出口的距离很短。如果入口氮氧化物上升快时，我们进行喷氨时要缓i慢的投入，因为氨和氮氧化物反应是有一定时间的滞后，那么反应就不会很完全，出口氮氧化物相应的上升后就会快速下降，如果投入过多，就会造成没有完全反应的氨逃逸。氨逃逸危害是很大的，脱硝平台上氨水增加喷投，过量的氨水会与烟气中的三氧化硫反应生成硫酸氢氨，硫酸氢铵在烟气中温度低时会形成液态，与飞灰表面物质反应后将改变颗粒物的表面形状，蕞终形成粘状腐蚀物，粘附在空气预热器上和布袋上，造成空气预热器的堵塞和布袋糊带，并且增大引风机的电耗。有时候我们运行操作过程中引风机的调频开度会逐步加大，所以我们在运行操作中，要尽量避免氨逃逸的现象发生，氨水投放时尽量避免大增大减要精心调整。
The large change of NOx at the denitration inlet is closely related to the change of coal quality, oxygen content, primary air volume and secondary air volume control during combustion adjustment. The denitration platform is set at the inlet of the cyclone separator, and the distance from the inlet to the outlet of the denitration reaction zone is very short. If the nitrogen oxide at the inlet rises rapidly, we should input slowly when we inject ammonia. Because the reaction between ammonia and nitrogen oxide has a certain time lag, the reaction will not be complete, and the nitrogen oxide at the outlet will decline rapidly after the corresponding rise. If we input too much, ammonia without complete reaction will escape. The danger of ammonia escape is great. The ammonia injection on the denitration platform is increased. The excess ammonia will react with sulfur trioxide in the flue gas to generate ammonia bisulfate. When the temperature in the flue gas is low, the ammonium bisulfate will form a liquid. After reacting with the surface substances of fly ash, it will change the surface shape of particles, and eventually form sticky corrosive substances, which will adhere to the air preheater and the cloth bag, resulting in the blockage of the air preheater and the paste belt of the cloth bag, And increase the power consumption of induced draft fan. Sometimes, the frequency modulation opening of the induced draft fan will gradually increase during our operation, so we should try to avoid ammonia escape during our operation, and try to avoid large increase during ammonia injection, which should be carefully adjusted.
脱硝是使用还原方法(氨气)有选择性的与氮氧化物反应生成无害的氮气和水。从而达到除去氮氧化物的目的。氮氧化物是怎么生成的呢？他是烟气中的氮气和氧气发生化学反应后形成的一种混合气体，以一氧化氮、二氧化氮为主比较稳定，还有三氧化二氮、四氧化二氮、五氧化二氮，这些混合物统称为氮氧化物，也就是硝烟。而二氧化硫的生成是烟气中的硫和氧气发生化学反应，而生成了二氧化硫。在硫和氮气氧化时会相互竞争，因此锅炉中二氧化硫排放量升高，氮氧化物的排放量就会相应降低。
Denitration is the selective reaction with nitrogen oxides using reduction method (ammonia) to generate harmless nitrogen and water. So as to achieve the purpose of removing nitrogen oxides. How do nitrogen oxides form? It is a mixed gas formed after the chemical reaction between nitrogen and oxygen in the flue gas. It is mainly nitric oxide and nitrogen dioxide, which are relatively stable. There are also nitrogen trioxide, nitrogen tetroxide and nitrogen pentoxide. These mixtures are collectively referred to as nitrogen oxides, that is, nitrous smoke. The formation of sulfur dioxide is the chemical reaction between sulfur and oxygen in the flue gas, which produces sulfur dioxide. The oxidation of sulfur and nitrogen will compete with each other, so the emission of sulfur dioxide in the boiler will increase, and the emission of nitrogen oxides will decrease accordingly.
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2022-06-27
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