CN201053675Y - Gas reburning burner - Google Patents

Abstract

The utility model relates to a gas reburning burner which comprises a casing, a gas joint and a flange. The utility model is characterized in that a venturi tube is arranged inside the casing, and consists of a tapered segment, a mixed segment and a diffuser; a gas chamber is formed between the casing and the venturi tube; a junction of the upstream of the mixed segment and the tapered segment of the venturi tube is provided with an air inlet ring; gas in the gas chamber enters into the venturi tube from the air inlet ring and mixes with high pressure steam. The utility model is simple in structure, firm, durable and has a long service life; the gas pressure application scope of the gas reburning burner can be wide caused by the negative pressure produced by the venturi tube, and the gas reburning burner can operate with gas of high pressure, medium pressure or low pressure; the high pressure steam carrier can guarantee that the reburning fuel is sufficiently and uniformly mixed with the flue gas from the upstream, and guarantee the effect that the NOX emission is reduced by reburning.

Description

gas reburn burner

technical field

The utility model relates to a gas burner, in particular to a burner for reburning in a furnace.

Background

At present, human beings are facing three major problems of resources, environment and population. In recent years, the environmental problems caused by energy are quite serious. Among them, nitrogen oxides are one of the main harmful substances that pollute the atmosphere. my country's energy is dominated by coal, and the air pollutants produced by coal combustion account for a large proportion of the total pollutant emissions, of which nitrogen oxides account for 67%.

Reburning technology belongs to low NOx combustion technology. Reburning Technology (ReburningTechology) is also known as fuel staged (zone) combustion technology in the furnace. That is to say, the furnace is divided into three zones: main combustion zone, reburning zone and burnout zone, and 80%-85% of the fuel is sent to the main combustion zone. The fuel in the combustion zone is called the main fuel, and there is excess air in the main combustion zone, which is an oxidizing atmosphere. The remaining 15%-20% of the fuel is sent to the reburning zone above the main combustion zone, and a strong reducing atmosphere is formed under the condition of α<1, so that the NOx generated in the main combustion zone is eliminated in the reburning zone. It is reduced to nitrogen molecules (N ₂ ), and the fuel sent to the reburning zone is called reburning fuel. In the reburning zone, not only the generated NOx is reduced, but also the formation of new NOx can be suppressed, so that the emission concentration of NOx can be further reduced. Finally, the combustion products enter the burnout zone and are sent to the overfired air (OFA) to achieve the ultimate goal of complete combustion. A small amount of NO will be regenerated during the burnout process, but in general, after using the reburning technology in the furnace, the final NOx emission of the pulverized coal furnace can be reduced by using a low NOx burner in the main combustion area. Another 50%-70% reduction in emissions. Therefore, using this technology, it is possible to control NOx emissions below 200mg/Nm3.

A large number of studies have shown that various hydrocarbon gaseous fuels such as natural gas are currently the most effective and widely used reburning fuels.

The existing reburning burner, due to the large furnace volume of large power plant boilers, and the small reburning fuel flow rate, cannot make the reburning fuel have enough momentum, forming a strong disturbance in the furnace, which is fully and evenly distributed in the reburning area to ensure that the reburning is reduced. NOx.

Contents of the invention

The utility model is to solve the technical problem of reburning the reburning burner to reduce NOx emissions, and provides a gas reburning burner, which can ensure that the reburning fuel and the flue gas from the upstream are fully and uniformly mixed, and the reburning can reduce NOx The effect of emissions.

In order to achieve the above purpose, the technical solution adopted by the utility model is: a gas reburning burner, including a shell, a gas joint, and a flange. Composed of , mixing section and diffuser section, a gas cavity is formed between the shell and the Venturi tube, and an inlet ring is provided at the joint between the upstream of the mixing section of the Venturi tube and the converging section, and the gas in the gas cavity It enters the Venturi tube from the intake ring and mixes with high-pressure water vapor.

The gas connection is arranged on the casing where the mixing section of the Venturi tube is located; the flange is arranged at the opening of the tapered section of the Venturi pipe and the front end of the casing.

The beneficial effects of the utility model are: the structure of the gas reburning burner is simple, firm, durable and long in life; the negative pressure generated by the Venturi tube makes the gas pressure of the gas reburning burner applicable to a wide range, and the supply of high, medium and low pressure gas can be operated ; The high-pressure water vapor carrier can ensure that the reburning fuel is fully and uniformly mixed with the flue gas from the upstream, so as to ensure the effect of reburning to reduce NOx emissions.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described further.

As shown in FIG. 1 , the gas reburning burner of the present invention includes a housing 1 , a gas connector 3 , a flange 4 , and a Venturi tube 2 .

The casing 1 surrounds the outside of the Venturi tube 2 , and the gas cavity 5 is between the casing 1 and the Venturi tube 2 . Venturi tube 2 is composed of tapered section 6 , mixing section 7 and diffuser section 8 . At the joint between the upstream of the mixing section 7 and the converging section 6, there is an intake ring 9, the gas enters the gas chamber 5 through the gas joint 3, and then enters the Venturi tube 2 from the intake ring 9 to mix with high-pressure water vapor.

The gas joint 3 is arranged on the casing 1 where the mixing section 7 of the Venturi tube 2 is located; the flange 4 is arranged at the opening of the tapered section 6 of the Venturi pipe 2 and the front end of the casing 1 .

The gas reburning burner is made of heat-resistant alloy steel. The gas reburning burner has a simple structure, firmness, durability, and long life; the negative pressure generated by the Venturi tube makes the gas reburning burner have a wide range of gas pressure, and it can operate with high, medium and low pressure gas.

The utility model uses high-pressure steam as a carrier, and the reburning fuel and steam are evenly mixed by the structure of the burner, and the momentum of high-pressure steam is used to generate strong disturbance in the boiler, which can ensure that the reburning fuel and the flue gas from the upstream are fully and uniformly Mixed to ensure the effect of reburning to reduce NOx emissions.

Claims (3)

1. gas reburning burner, comprise housing (1), gas joint (3), flange (4), it is characterized in that, described housing (1) is built-in with Venturi tube (2), Venturi tube (2) is made up of converging transition (6), mixer (7), diffuser (8), form combustion gas cavity (5) between housing (1) and the Venturi tube (2), mixer (7) upstream and converging transition (6) joint in Venturi tube (2) are provided with an air inlet ring (9), and the combustion gas in the combustion gas cavity (5) enters Venturi tube (2) from air inlet ring (9) and mixes with high-pressure steam.

2. gas reburning burner according to claim 1 is characterized in that, described gas joint (3) be arranged on Venturi tube (2) mixer (7) housing of living in (1) above,

3. gas reburning burner according to claim 1 is characterized in that, described flange (4) is arranged on converging transition (6) opening part and housing (1) front end of Venturi tube (2).

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