随着我国环保标准的进一步提高，不能满足国家环保标准排放的火力发电机组相继进行了低氮或脱硝改造。机组在进行低氮燃烧器和脱硝系统改造后，在实际运行中NOx的排放量均能满足2011版《火力发电厂污染物排放标准》要求，脱硝系统运行基本正常。
With the further improvement of China's environmental protection standards, coal-fired power units that cannot meet the national environmental protection standards have successively carried out low-nitrogen or denitrification transformation. In low nitrogen burner and denitration system after modification, in the actual operation of NOx emissions can meet the 2011 edition "coal-fired power plant emissions standard" requirement, denitration system running normally.

1、低氮燃烧及脱硝技术
1. Low-nitrogen combustion and denitrification technology

低氮燃烧机组主要是针对NOx的两种主要生成机理，在降低燃烧温度的同时，降低着火区域的氧气浓度。以抑制炉氮氧化物的生成。通过采用炉内低NOx燃烧技术，能将NOx排放浓度降低30%～60%。目前普遍采用的低氮燃烧技术主要是通过低氮燃烧器改造，来实现炉内低氧、分级配分的燃烧特性，降低NOx的减排。
The low nitrogen combustion unit is mainly aimed at two main generating mechanisms of NOx, which reduce the oxygen concentration in the ignition area while reducing the combustion temperature. To inhibit the formation of furnace nitrogen oxides. By using the low NOx combustion technology in the furnace, the NOx emission concentration can be reduced by 30% ~ 60%. Currently, the commonly used low-nitrogen combustion technology is mainly through the transformation of low-nitrogen burner to realize the combustion characteristics of low-oxygen and graded blending in the furnace and reduce the emission reduction of NOx.

由于炉内低氮燃烧技术的局限性,使得NOx的排放不能很好的满足环保要求，为进一步降低NOx的排放，必须对燃烧后的烟气进行脱硝处理。目前通行的烟气脱硝工艺大致可分为干法、半干法和湿法3类。其中干法SCR脱硝工艺以其脱硝装置结构简单、运行方便、可靠性高、脱硝效率高、一次投资相对较低等诸多优点，在我国得到了广泛的商业应用。
Due to the limitation of the low-nitrogen combustion technology in the furnace, the emission of NOx cannot meet the requirements of environmental protection. In order to further reduce the emission of NOx, it is necessary to denitrify the smoke after combustion. The current flue gas denitrification process can be divided into dry, semi-dry and wet processes. Including dry SCR denitration technology with its denitration device has simple structure, convenient operation and high reliability, high denitration efficiency, a lot of advantages, an investment is relatively low in our country has been widely commercial application.

SCR脱硝反应器按照相对于除尘器的安装位置，可分为高含尘和低含尘两类。但由于低含尘需要安装蒸汽加热器和烟气换热器(GGH)，系统复杂，投资大，故一般选择高含尘工艺。SCR装置主要由脱硝反应剂制备系统和反应器本体组成。
The SCR denitrification reactor can be divided into high dust content and low dust content according to the installation position of relative dust collector. However, because the low dust content requires the installation of steam heater and gas heat exchanger (GGH), the system is complex and the investment is large, so the high dust content technology is generally chosen. The SCR device is mainly composed of the preparation system of denitrification reaction agent and the reactor body.

通过向反应器内喷入脱硝反应剂NH3，将NOx还原为氮气和水蒸气。制氨一般有尿素、液氨、氨水等3种方法。目前主要采用尿素和液氨两种制氨方法。脱硝催化剂其材料一般以TiO2为载体，并掺入V2O5和WO3等活性成分。催化剂的活性温度范围从300℃～420℃[3]不等。催化剂有蜂窝式和板式两种。
The NOx was reduced to nitrogen and water vapor by spraying the denitrification reagent NH3 into the reactor. Ammonia production generally has urea, liquid ammonia, ammonia water and other three methods. At present, urea and liquid ammonia are mainly used to make ammonia. The denitrification catalyst is usually supported by TiO2 and mixed with V2O5 and WO3. The activity of the catalyst temperature range from 300 ℃ to 420 ℃ range [3]. There are two kinds of catalyst, honeycomb and plate.

机组之前未采用低氮燃烧方式，且无脱硝装置。此类机组在氮氧化物减排改造中，改造幅度大，低氮燃烧器改造以及加装脱硝装置。上述几种进行脱硝改造的机组，同时进行了空预器、除尘器以及引风机的改造。

No low nitrogen combustion method and no denitrification device have been used before. In the modification of nitrogen oxide reduction, the modification range is large, the modification of low nitrogen burner and the addition of denitrification device. The above mentioned denitrification units have been modified with air preheater, dust collector and fan.