1. The primary air and powder nozzle of the pulverized coal fired boiler with the additive nozzle is characterized by comprising a pulverized coal airflow nozzle (2), a primary air and powder nozzle wall surface (1) is arranged in the circumferential direction of the pulverized coal airflow nozzle (2), at least one combustion-supporting air nozzle (6) with the additive nozzle is arranged between the primary air and powder nozzle wall surface (1) and the pulverized coal airflow nozzle (2) in a partition plate (8) division mode, and the additive nozzle (7) is arranged on the combustion-supporting air nozzle (6) of the additive nozzle.

2. The pulverized coal fired boiler primary air and pulverized coal burner with an additive nozzle as claimed in claim 1, characterized in that an upper combustion air nozzle (3), a side combustion air nozzle (4) and a lower combustion air nozzle (5) are further divided between the primary air and pulverized coal burner wall surface (1) and the pulverized coal gas stream nozzle (2) through a partition plate (8).

3. The primary air and pulverized coal nozzle of a pulverized coal fired boiler with an additive nozzle as claimed in claim 2, characterized in that the upper combustion air nozzle (3), the side combustion air nozzle (4) and the lower combustion air nozzle (5) exist simultaneously or one or more of them are removed.

4. The pulverized coal fired boiler primary air and pulverized coal injection port with an additive injection port as claimed in claim 2, characterized in that the combustion air injection port (6) with an additive injection port is capable of forming a larger circle of tangency in the furnace (14) than the pulverized coal gas flow injection port (2).

5. The pulverized coal fired boiler primary air and pulverized coal burner with an additive nozzle as claimed in claim 2, characterized in that the combustion-supporting air from the secondary air box (13) is injected into the furnace chamber (14) through the upper combustion-supporting air nozzle (3), the side combustion-supporting air nozzle (4), the lower combustion-supporting air nozzle (5) and the combustion-supporting air nozzle (6) with the additive nozzle, and the jet direction of the combustion-supporting air is the same as that of the pulverized coal airflow nozzle (2).

6. The pulverized coal fired boiler primary air and pulverized coal burner with the additive nozzle as claimed in claim 1, characterized in that the combustion air nozzle (6) of the additive nozzle is arranged on one side of the pulverized coal airflow nozzle (2) close to the boiler water-cooled wall (10).

7. The pulverized coal fired boiler primary air and powder injection port with an additive injection port as claimed in claim 1, wherein the pulverized coal fired boiler primary air and powder injection port is used for a boiler burner with a four-corner tangential firing mode.

8. The pulverized coal fired boiler primary air and powder injection port with an additive injection port as claimed in claim 1, wherein the pulverized coal fired boiler primary air and powder injection port is used for boilers with hexagonal tangential circle, octagonal tangential circle and double tetragonal tangential circle combustion modes.

Background

When the boiler is fired with coal easy to form slag, water-cooled wall slag formation is easy to occur, and the safe and economic operation of the boiler is seriously influenced.

The addition of the anti-slagging additive into the boiler is an effective way for preventing slagging of the water-cooled wall of the coal boiler which is easy to slag. The conventional additive adding mode is mainly a mode of premixing the coal fed into the furnace on a coal feeding belt, a large amount of additives cannot reach the wall surface of a water cooling wall and cannot play a slag bonding prevention role, so that the additives are wasted, the utilization rate of the additives is low, and the adding cost is too high to have large-scale industrial application value.

Disclosure of Invention

The invention provides a primary air-powder nozzle of a pulverized coal boiler with an additive nozzle, which aims to solve the problems of low additive utilization rate and high additive cost of the existing boiler anti-slagging additive adding mode, and can obviously reduce the additive usage amount and the additive adding cost.

The invention is realized by adopting the following technical scheme:

the pulverized coal boiler primary air-powder nozzle with the additive nozzle comprises a pulverized coal airflow nozzle, wherein a primary air-powder nozzle wall surface is arranged in the circumferential direction of the pulverized coal airflow nozzle, at least one combustion-supporting air nozzle with the additive nozzle is divided between the primary air-powder nozzle wall surface and the pulverized coal airflow nozzle through a partition plate, and the additive nozzle is arranged on the combustion-supporting air nozzle of the additive nozzle.

The invention is further improved in that an upper combustion-supporting air nozzle, a side combustion-supporting air nozzle and a lower combustion-supporting air nozzle are also divided between the wall surface of the primary air powder nozzle and the pulverized coal airflow nozzle through a partition plate.

The invention has the further improvement that the upper combustion-supporting air nozzle, the side combustion-supporting air nozzle and the lower combustion-supporting air nozzle exist at the same time or one or more of the upper combustion-supporting air nozzle, the side combustion-supporting air nozzle and the lower combustion-supporting air nozzle are removed.

The invention is further improved in that the combustion-supporting air nozzle with the additive nozzle can form a larger tangent circle in the hearth than the pulverized coal airflow nozzle.

The invention has the further improvement that the combustion-supporting air from the secondary air box is sprayed into the hearth by the upper combustion-supporting air nozzle, the side combustion-supporting air nozzle, the lower combustion-supporting air nozzle and the combustion-supporting air nozzle with the additive nozzle, and the jet direction of the combustion-supporting air is the same as that of the pulverized coal airflow nozzle.

The invention is further improved in that a combustion-supporting air nozzle of the additive nozzle is arranged on one side of the pulverized coal airflow nozzle close to the water-cooled wall of the boiler.

The invention has the further improvement that the primary air powder nozzle of the pulverized coal boiler is used for a boiler burner with four corner tangential firing modes.

The invention has the further improvement that the primary air powder nozzle of the pulverized coal boiler is used for boilers with combustion modes of hexagonal tangent circle, octagonal tangent circle and double four-corner tangent circle.

The invention has at least the following beneficial technical effects:

1. the side surface of the pulverized coal airflow nozzle is provided with the slag-bonding preventing additive nozzle, slag-bonding ash particles which are easy to be bonded after combustion are firstly reacted with the slag-bonding preventing additive before contacting with the water-cooled wall, and the water-cooled wall can be contacted after the slag-bonding property is reduced, so that the problem of slag bonding of the water-cooled wall of the boiler can be solved;

2. the additive is only added in the water-cooled wall area at the periphery of the hearth, and the additive is not used in a wider area which is not contacted with the water-cooled wall in the hearth, so that the use amount of the additive can be obviously reduced, and the use cost is greatly reduced.

In summary, the primary air powder nozzle of the boiler burner with the additive nozzle has the function of introducing pulverized coal airflow, and can also introduce the anti-slagging additive, the additive is mainly distributed on one side close to a water-cooled wall, and no additive exists in the positions, such as the center of a hearth and the like, where the additive is not needed, so that the use amount of the additive can be greatly reduced and the use cost can be reduced on the premise of achieving the same anti-slagging effect.

Drawings

FIG. 1 is a schematic diagram of a primary air-powder nozzle of a pulverized coal boiler with an additive nozzle according to the present invention.

Fig. 2 is a sectional view of a section B-B in the horizontal direction in fig. 1, and the outlet section of the additive nozzle 7 may be inside the combustion air nozzle 6 with the additive nozzle or protrude from the outlet section of the combustion air nozzle 6 with the additive nozzle, depending on the actual situation of the specific boiler.

Fig. 3 is a cross-sectional view of a section taken along the vertical direction a-a.

FIG. 4 is a schematic diagram of an embodiment of primary air and pulverized coal nozzles of a pulverized coal fired boiler with additive nozzles on a tangential firing boiler.

Description of reference numerals:

the device comprises a primary air and powder nozzle wall surface 1, a pulverized coal airflow nozzle 2, an upper combustion-supporting air nozzle 3, a side combustion-supporting air nozzle 4, a lower combustion-supporting air nozzle 5, a combustion-supporting air nozzle 6 with an additive nozzle, an additive nozzle 7, a partition plate 8, an additive inlet 9, a boiler water-cooling wall 10, a first tangent circle 11, a second tangent circle 12, a secondary air box 13 and a hearth 14.

Detailed Description

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1 to 3, the primary air nozzle of the pulverized coal boiler with the additive nozzle provided by the invention comprises a pulverized coal airflow nozzle 2, an upper combustion-supporting air nozzle 3, a side combustion-supporting air nozzle 4, a lower combustion-supporting air nozzle 5 and a combustion-supporting air nozzle 6 with the additive nozzle, wherein the combustion-supporting air nozzle is arranged around the pulverized coal nozzle, so that combustion air is supplemented, and the nozzles are cooled to avoid burning loss of the nozzles. The combustion-supporting air nozzle 6 with the additive nozzle is arranged in the combustion-supporting air nozzle on one side of the pulverized coal airflow nozzle close to the boiler water-cooling wall, the additive is sprayed and then mixed with the combustion-supporting air and further sprayed into the hearth 14, an additive airflow barrier is established between the pulverized coal airflow and the boiler water-cooling wall 10, easily-slagging ash particles after the pulverized coal airflow is combusted can react with the additive in the process of approaching the water-cooling wall and become ash particles which are not easily slagging, and even if the ash particles reach the water-cooling wall, serious slagging can not be formed.

The pulverized coal airflow is sprayed into the hearth through the pulverized coal airflow nozzle 2; the upper combustion-supporting air nozzle 3, the side combustion-supporting air nozzle 4, the lower combustion-supporting air nozzle 5 and the combustion-supporting air nozzle 6 with the additive nozzle around the pulverized coal airflow nozzle 2 are combustion-supporting air nozzles, and combustion-supporting air is introduced into the nozzles and is also used for cooling and protecting the primary air powder nozzle wall surface 1 and the partition plate 8 of the whole combustor. And 7 is an additive nozzle, the additive nozzle is positioned in a combustion-supporting air nozzle 6 with the additive nozzle on the side edge of the pulverized coal airflow nozzle 2, the additive airflow is mixed with combustion-supporting air in the combustion-supporting air nozzle 6 with the additive nozzle and then is sprayed into a hearth 14, and an additive inlet 9 is arranged on the additive nozzle 7.

As shown in fig. 4, the embodiment of the present invention will be described by taking a tangential firing boiler burner as an example, but the present invention is not limited to the tangential firing boiler, and can be applied to a boiler of a firing system such as a hexagonal tangential boiler, an octagonal tangential boiler, or a double tangential boiler.

The boiler burner uses the primary air powder nozzles of the invention, wherein one layer is arranged as shown in figure 4.

The pulverized coal airflow is sprayed into a hearth 14 through a pulverized coal airflow nozzle 2, and a smaller second tangent circle 12 is formed in the furnace.

The combustion-supporting air from the secondary air box 13 is sprayed into the hearth 14 by the upper combustion-supporting air nozzle 3, the side combustion-supporting air nozzle 4, the lower combustion-supporting air nozzle 5 and the combustion-supporting air nozzle 6 with the additive nozzle, and the jet flow direction of the combustion-supporting air is the same as that of the pulverized coal airflow nozzle 2.

The additive airflow enters a combustion-supporting air nozzle 6 with an additive nozzle from an additive nozzle 7, and is mixed with combustion-supporting air in the combustion-supporting air nozzle 6 with the additive nozzle and then sprayed into a hearth 14, and a first tangent circle 11 formed in the furnace is larger than a second tangent circle 12 because the combustion-supporting air nozzle 6 with the additive nozzle is arranged on one side closer to a water-cooled wall of the hearth. Therefore, the additive airflow is positioned between the pulverized coal airflow and the boiler water-cooled wall 10, and the ash particles after the pulverized coal airflow is combusted must firstly pass through the additive airflow when reaching the water-cooled wall, and are changed from easy-to-slag-bonding particles into difficult-to-slag-bonding particles after reacting with the additive, so that the easy-to-slag-bonding particles are prevented from being adhered to the water-cooled wall to form slag bonding.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.