一、What is a low nitrogen boiler?

Low-nitrogen boilers generally refer to gas-fired boilers with nitrogen oxide emissions below 80mg/m3.

• Ultra-high efficiency (up to 108%);
• Ultra-low emission of harmful substances (NOX is less than 8ppm/18mg/m3);
• Ultra-low footprint (1.6m2/tonnage);
• Ultra-intelligent control (Siemens controller);
• Ultra-low exhaust gas temperature (as low as 35℃);
• Ultra-quiet operation (45 dB);
• Ultra-safety protection (11 layers of protection);
• Super exquisite appearance (cool white appearance);
• Super user-friendly control panel (LCD);
• Long service life (40 years);
• Ultra-low gas pressure (1.7~2.1kpa);
• Ultra-high ratio adjustment range: 1:7 (15~100%);
• Universal load bearing wheel (easy to transport and fix).

二、How low nitrogen boilers work

Low-nitrogen boilers are upgraded on the basis of ordinary boilers. Compared with traditional boilers, low-nitrogen boilers mainly use various combustion optimization control technologies to reduce combustion temperature, thereby reducing NOx emissions, and easily achieve NOx emissions less than 80mg/m3, Even some low nitrogen boiler NOx emissions can be as low as 30mg/m3.

The low nitrogen combustion technology mainly controls the combustion temperature and reduces the generation of thermal nitrogen oxides.

三、What kinds of low nitrogen boilers are there?

1、Flue gas recirculation low nitrogen boiler

The flue gas recirculation low-nitrogen boiler is a pressure head that uses combustion-supporting air to suck part of the combustion flue gas back into the burner, where it is mixed with air for combustion. Due to the recirculation of the flue gas, the heat capacity of the combustion flue gas is large, so that the combustion temperature is controlled at 1000 degrees, thereby reducing the formation of nitrogen oxides.

2、Fully premixed low nitrogen boiler

The fully premixed low-nitrogen boiler adopts the fully premixed technology, which can achieve an ideal mixing ratio by adjusting the gas and combustion air, and achieve complete combustion of the fuel. And the low-nitrogen boiler burner can form a uniformly mixed gas mixture before the gas and combustion-supporting air enter the furnace, and then burn stably, reducing the emission of nitrogen oxides.

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Advantages: uniform radiator heat transfer, improved heat transfer intensity; optimal combustion speed, temperature and safety; increased radiation area; adjustable unit radiation intensity; Recovery of latent heat of vaporization.

四、Retrofit of Low Nitrogen Boiler

01）Boiler Low Nitrogen Retrofit

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Boiler low-nitrogen transformation is flue gas recirculation technology, which is a technology to reduce nitrogen oxides by reintroducing part of the boiler exhaust smoke into the furnace and mixing it with natural gas and air for combustion. Using the flue gas recirculation technology, the combustion temperature in the core area of the boiler is reduced, and the excess air coefficient remains unchanged. Under the condition that the boiler efficiency is not reduced, the formation of nitrogen oxides is inhibited, and the purpose of reducing nitrogen oxide emissions is achieved.

In order to ensure the complete combustion of the fuel, it is usually necessary to supply a certain proportion of excess air in addition to the theoretical air volume required for combustion. On the premise of ensuring the thermal efficiency of combustion, a smaller excess air coefficient is selected to minimize the oxygen concentration in the flue gas. , will be able to effectively inhibit the formation of NOx.

In fact, the low-nitrogen transformation of boilers is flue gas recirculation technology, which is a technology to reduce nitrogen oxides by reintroducing part of the boiler exhaust smoke into the furnace and mixing it with natural gas and air for combustion. Using the flue gas recirculation technology, the combustion temperature in the core area of the boiler is reduced, and the excess air coefficient remains unchanged. Under the condition that the boiler efficiency is not reduced, the formation of nitrogen oxides is suppressed, and the purpose of reducing nitrogen oxide emissions is achieved.

When the boiler is running at high load, the air volume of the blower is usually increased to increase the furnace temperature. At this time, the excess air coefficient is often large, the furnace temperature is high, and the amount of NOx generated is large. The low-nitrogen boiler runs smoothly under high load conditions, and at the same time controls the furnace temperature, which can effectively suppress the generation of NOx.

NOx nitrogen oxides are generated due to the oxidation of N2 in the combustion air under the action of high temperature. The low-nitrogen transformation can effectively control the combustion temperature below 1000 degrees. concentration is greatly reduced.

02）Low-nitrogen Retrofit of Gas Boiler

1）Boiler main body renovation

For low-nitrogen transformation of general large-scale traditional steel furnaces, it is usually necessary to transform the furnace and heating area, so that the gas boiler burns more fully, and the nitrogen oxide content in the flue gas is further reduced, and finally the purpose of low-nitrogen gas transformation is achieved.

2）Burner Retrofit

Generally speaking, the low nitrogen retrofit method for gas boilers is burner retrofit. We choose to replace the low-nitrogen burner to make the burner more energy-saving, environmentally friendly and efficient, thereby reducing the content of ammonia oxides in the boiler exhaust. Low-nitrogen burners are divided into ordinary and ultra-low nitrogen. The NOx content of ordinary burners is between 80mg/m3 and 150mg/m3, while the NOx content of ultra-low NOx burners is lower than 30mg/m3.

The low-ammonia transformation of gas-fired boilers is mainly carried out in the above two ways. Burner low nitrogen retrofit, usually suitable for small gas boilers. If the large gas boiler is to be retrofitted with low nitrogen, the furnace and the burner need to be carried out at the same time, so that the main boiler and the burner can be matched and operated efficiently.