CN111686954A

CN111686954A - Conical nozzle of pneumatic soot blowing system of coal-fired boiler and soot blowing method

Info

Publication number: CN111686954A
Application number: CN202010741695.4A
Authority: CN
Inventors: 孙少鹏; 李凯; 王贵华; 宁玉琴
Original assignee: Hangzhou Huadian Energy Engineering Co ltd
Current assignee: Hangzhou Huadian Energy Engineering Co ltd
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2020-09-22

Abstract

The invention discloses a conical nozzle of a pneumatic soot blowing system of a coal-fired boiler and a soot blowing method, which are mainly used for carrying out pneumatic soot blowing at the position with serious soot accumulation in the horizontal and tail flues of the coal-fired boiler of a thermal power plant and can effectively solve the problem of soot accumulation in the horizontal and tail flues of the coal-fired boiler. The nozzle includes conical air chamber, and conical air chamber's bottom is equipped with sunken formula welding mouth, and conical air chamber's lower part evenly is equipped with four spouts down all around, and conical air chamber's upper portion evenly is equipped with two spouts all around, goes up spout and spout staggered arrangement down. During the use, weld compressed air or steam medium through pipeline and formula of sinking welding mouth, during the medium flowed into conical air chamber, spout the spout blowout on four lower spouts and two from conical air chamber respectively, the medium to the outer wall tangent line 90 degrees contained angle directions with conical air chamber flat blow the direct injection, blow up the deposition fluidization in the flue, upper and lower double-deck flat jet current that blows has strengthened the disturbance to the deposition, effectively solves the flue deposition and piles up the problem.

Description

Conical nozzle of pneumatic soot blowing system of coal-fired boiler and soot blowing method

Technical Field

The invention relates to a conical nozzle of a pneumatic soot blowing system of a coal-fired boiler and a soot blowing method, which are mainly used for carrying out pneumatic soot blowing at the position with serious soot accumulation in the horizontal and tail flues of the coal-fired boiler of a thermal power plant and can effectively solve the problem of soot accumulation in the horizontal and tail flues of the coal-fired boiler.

Background

When a coal-fired boiler of a large-scale thermal power plant operates, a large amount of dust can be generated in horizontal and tail flues generally, and if the dust in the flues can not be taken away by flue gas in time, the situation that the dust is more and more serious can be caused, and the operation safety of the coal-fired boiler is damaged.

When a coal-fired boiler of a large-scale thermal power plant operates, ash is easily accumulated in horizontal and tail flues, the horizontal flue cannot be carried away by smoke due to the fact that smoke flows to form a negative pressure backflow area in a certain area, smoke turbulence and flowing dead angle areas exist in the tail flues, particularly at reducing positions, elbows and the like, and the smoke cannot be carried away by the smoke to form a large amount of ash. A large amount of dust in the flue firstly influences a flue gas flow field in the flue, so that the flue gas flow is uneven, and the local heat exchanger is scoured and worn; a large amount of deposited ash is accumulated on the surface of the heat exchanger, and the heat exchange of the heat exchanger is influenced; a large amount of dust is accumulated in the tail flue, so that flue collapse accidents can be caused, and the safe operation of the boiler is seriously influenced.

The conventional soot blowers on coal-fired boilers of thermal power plants respectively have advantages and disadvantages, such as steam soot blowers, sound wave soot blowers, gas pulse soot blowers and the like. The steam soot blowing effect is good, but soot blowing dead angles exist, and blowing damage is caused to a heat exchange surface; the acoustic soot blowing effect is limited; the pulse soot blower generates huge sound energy and a large amount of high-temperature and high-speed gas instantly, so that the soot is splashed and taken away along with the flue gas, but the heat exchange surface is oscillated, impacted and washed in a shock wave mode, and the three common soot blowers can not effectively remove the soot in horizontal, elbow and dead-angle flues.

At present, a pneumatic soot blowing system using steam or compressed air as a medium is demonstrated and applied to a coal-fired boiler, and the pneumatic soot blowing mode can effectively perform pneumatic soot blowing on an area where soot is easy to accumulate in a flue at fixed points and at fixed time, so that the accumulated soot is blown upwards and taken away by flue gas. The Chinese patent application with the publication number of CN107143867A discloses a soot blowing system and a soot blowing method for a horizontal flue of a boiler, wherein the system comprises a compressed air main pipe and a plurality of soot blowing units, and each soot blowing unit comprises a compressed air branch pipe, a manual gate valve, an electromagnetic valve, a pressure gauge, a plurality of blast caps and a plurality of abrasion-proof tiles. The nozzle is used as a key part, has a single structure, has dead corners in a soot blowing area, and has the problem of limited soot blowing effect.

In conclusion, the pneumatic soot blowing system can effectively solve the problem of soot deposition at dead corners of horizontal and tail flues of the coal-fired boiler. However, the nozzle is used as a key part, plays an important role in the pneumatic soot blowing effect, and has important significance in pertinently applying nozzles in different forms according to the characteristics of different flue soot deposits.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides the conical nozzle which is reasonable in design, simple in structure, lower in cost and safe in work, adopts the conical nozzle with double-layer nozzles to improve the soot blowing effect of the pneumatic soot blowing system and is used for improving the soot blowing capacity of the pneumatic soot blowing system of the horizontal and tail flues of the coal-fired boiler of the thermal power plant.

The technical scheme adopted by the invention for solving the problems is as follows: the utility model provides a coal fired boiler strength soot blowing system conical nozzle which characterized in that: the device comprises a conical air chamber, wherein a sunken welding port is formed in the bottom end of the conical air chamber and used for connecting a compressed air or steam medium pipeline, four lower nozzles are uniformly arranged on the periphery of the lower portion of the conical air chamber, two upper nozzles are uniformly arranged on the periphery of the upper portion of the conical air chamber, and the upper nozzles and the lower nozzles are arranged in a staggered mode.

Furthermore, the jet flow directions of all the lower nozzles and the upper nozzles form 90-degree included angles with the tangential direction of the outer wall of the conical air chamber.

The soot blowing method of the conical nozzle of the pneumatic soot blowing system of the coal-fired boiler is characterized in that: the method comprises the following steps of welding compressed air or steam medium with a sunken welding port through a pipeline, enabling the medium to flow into a conical air chamber and be sprayed out from four lower nozzles and two upper nozzles of the conical air chamber respectively, blowing the medium to a direction perpendicular to the 90-degree included angle of the tangent line of the outer wall of the conical air chamber, blowing deposited dust in a flue to be fluidized, and enhancing the disturbance of the deposited dust through upper and lower double-layer horizontal blowing jet flows to effectively solve the problem of deposited dust accumulation in the flue.

Furthermore, the conical nozzles can be arranged in a plurality of groups in the ash deposition area of the flue according to the ash removal area.

Furthermore, the installation direction of the conical nozzle is that the central line of the conical air chamber is vertical to the wall surface or the heat exchange surface of the flue.

Furthermore, the mounting height of the conical nozzle is flexibly adjusted according to the height of accumulated dust in the flue, and the maximum mounting height is 500mm away from the wall surface or the heat exchange surface of the flue.

Compared with the prior art, the invention has the following advantages and effects:

1. the conical nozzle can effectively solve the problem of dust deposition at dead corners of the flue of the coal-fired boiler aiming at the characteristics of dust deposition of different flues.

2. The conical nozzle has the advantages of reasonable design, simple structure, lower cost, safe work, convenient use and wide market prospect.

3. The conical nozzle is designed to improve the soot blowing effect of the pneumatic soot blowing system by adopting upper and lower double-layer direct injection, and improve the capacity of the soot blowing system.

4. The medium sprayed by the upper and lower six nozzles of the conical nozzle forms a flat-blowing direct-injection compressed air or steam jet flow field to blow and fluidize the deposited dust in the flue, and the flat-blowing direct-injection jet flow enhances the disturbance of the deposited dust and effectively solves the problem of the deposited dust accumulation in the flue.

Drawings

FIG. 1 is a schematic view of a conical nozzle according to an embodiment of the present invention.

In the figure: conical air chamber 1, sunken welding mouth 2, lower spout 3, last spout 4.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.

Examples are given.

Referring to fig. 1, in this embodiment, a conical nozzle of a coal-fired boiler pneumatic soot blowing system includes a conical air chamber 1, a sunk welding port 2 is arranged at the bottom end of the conical air chamber 1 and used for connecting a compressed air or steam medium pipeline, four lower nozzles 3 are uniformly arranged around the lower portion of the conical air chamber 1, two upper nozzles 4 are uniformly arranged around the upper portion of the conical air chamber 1, and the upper nozzles 4 and the lower nozzles 3 are arranged in a staggered manner.

In this embodiment, the jet flow directions of all the lower nozzles 3 and the upper nozzles 4 form an included angle of 90 degrees with the tangential direction of the outer wall of the conical air chamber 1.

In this embodiment, the conical nozzles can be arranged in multiple groups in the soot deposition area of the flue according to the soot cleaning area.

In this embodiment, the installation direction of the conical nozzle is that the central line of the conical air chamber 1 is perpendicular to the wall surface or the heat exchange surface of the flue.

In the embodiment, the mounting height of the conical nozzle is flexibly adjusted according to the height of accumulated dust in the flue, and the mounting maximum height is 500mm away from the wall surface or the heat exchange surface of the flue.

The soot blowing method comprises the following steps: the coal-fired boiler pneumatic soot blowing system conical nozzle is arranged in the areas where soot is easily accumulated in the horizontal and tail flues of the coal-fired boiler, soot is blown by using compressed air or steam as a medium, the compressed air or the steam medium is welded with the sunken welding port 2 through a pipeline, the medium flows into the conical air chamber 1 and is respectively sprayed out from four lower nozzles 3 and two upper nozzles 4 of the conical air chamber 1, the medium is blown straight and directly projected in the direction of 90-degree included angles of the outer wall tangent line of the conical air chamber 1, the soot in the flues is blown and fluidized, the disturbance to the soot is enhanced by upper and lower double-layer flat blowing jet flows, and the problem of accumulation of the soot in the flues is effectively solved.

In the embodiment, the soot blowing medium adopted by the conical nozzle is compressed air or steam with the pressure of 0.8-1MPa, and the usage and pressure of the compressed air or steam are ensured.

In the embodiment, the conical nozzle adopts an intermittent soot blowing mode, each blowing time is 3 minutes, and each blowing time is 5 minutes.

Those not described in detail in this specification are well within the skill of the art.

Although the present invention has been described with reference to the above embodiments, it should be understood that the scope of the present invention is not limited thereto, and that various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. The utility model provides a coal fired boiler strength soot blowing system conical nozzle which characterized in that: including conical air chamber (1), the bottom of conical air chamber (1) is equipped with sunken formula welding joint (2) for connect compressed air or steam medium pipeline, the lower part of conical air chamber (1) evenly is equipped with four spouts (3) down all around, the upper portion of conical air chamber (1) evenly is equipped with spout (4) on two all around, go up spout (4) and spout (3) staggered arrangement down.

2. The conical nozzle of the coal-fired boiler pneumatic soot blowing system of claim 1, characterized in that: the jet flow directions of all the lower nozzles (3) and the upper nozzles (4) form 90-degree included angles with the tangential direction of the outer wall of the conical air chamber (1).

3. The conical nozzle of the coal-fired boiler pneumatic soot blowing system of claim 1, characterized in that: when the device is installed, the central line of the conical air chamber (1) is vertical to the wall surface or the heat exchange surface of the flue.

4. The soot blowing method of the conical nozzle of the pneumatic soot blowing system of the coal-fired boiler according to any one of claims 1 to 3, characterized in that: the method comprises the following steps of welding compressed air or steam medium with a sunken welding port (2) through a pipeline, enabling the medium to flow into a conical air chamber (1), and respectively spraying out from four lower nozzles (3) and two upper nozzles (4) of the conical air chamber (1), enabling the medium to be blown straight at an included angle of 90 degrees with the tangent line of the outer wall of the conical air chamber (1), blowing ash in a flue to be fluidized, enhancing the disturbance of the ash through upper and lower double-layer blowing jet flow, and effectively solving the problem of ash accumulation in the flue.