CN216281352U

CN216281352U - Pulverized coal fired boiler device and pulverized coal fired boiler system utilizing low-calorific-value fuel gas

Info

Publication number: CN216281352U
Application number: CN202121787374.4U
Authority: CN
Inventors: 李丽; 付广旭; 钟晓燕; 刘朋; 李涛; 蔺龙; 郝文浩
Original assignee: Shaanxi Future Energy Chemical Co ltd
Current assignee: Shaanxi Future Energy Chemical Co ltd
Priority date: 2021-08-02
Filing date: 2021-08-02
Publication date: 2022-04-12
Anticipated expiration: 2031-08-02

Abstract

The utility model relates to the technical field of industrial boiler combustion, and particularly provides a pulverized coal boiler device and a pulverized coal boiler furnace ignition system utilizing low-calorific-value fuel gas. The pulverized coal boiler device comprises a pulverized coal boiler hearth, boiler ignition layer burners are arranged on four corners in the pulverized coal boiler hearth, and the boiler ignition layer burners are supplied with combustion gas by a combustion gas header pipe. The problem of in the prior art adopt low calorific value gas to light the in-process of burning furnace, because the gas power is not enough there is local flame-out phenomenon is solved.

Description

Pulverized coal fired boiler device and pulverized coal fired boiler system utilizing low-calorific-value fuel gas

Technical Field

The utility model relates to the technical field of industrial boiler combustion, and particularly provides a pulverized coal boiler device and a pulverized coal boiler furnace ignition system utilizing low-calorific-value fuel gas.

Background

The statements herein merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The by-product low-calorific-value fuel gas can be produced in the coal chemical production process, the traditional furnace ignition mode is diesel oil furnace ignition, when smoke containing oil smoke passes through the denitration catalyst, the surface of the catalyst is easy to be blocked, the service life of the catalyst is reduced, the denitration rate of the catalyst is reduced, and when the smoke flows through the bag-type dust remover, the oil smoke causes the bag pasting phenomenon of a filter bag, particularly the filter bag which is not sprayed and used after replacement. In addition, the boiler ignition diesel oil is outsourcing diesel oil, the fuel gas is a byproduct of a synthesis system, the diesel oil is used for ignition, the economic cost is increased, and the fuel gas is not reasonably and fully utilized.

Therefore, the prior art provides a device for igniting a combustion furnace by using fuel gas, but the inventor finds that when the fuel gas is adopted for ignition, the fuel gas is usually low-calorific-value fuel gas, the power of the fuel gas is insufficient, so that the heat after ignition cannot be distributed in the whole combustion furnace, and the local flameout phenomenon is caused.

SUMMERY OF THE UTILITY MODEL

The problem of local flameout phenomenon exists because of insufficient gas power in the process of igniting the combustion furnace by adopting low-calorific-value gas in the prior art is solved.

In one or some embodiments of the present invention, a pulverized coal fired boiler device is provided, which includes a pulverized coal fired boiler furnace, wherein boiler ignition layer burners are disposed at four corners of the pulverized coal fired boiler furnace, and the boiler ignition layer burners are supplied with combustion gas by a combustion gas header pipe.

In one or more embodiments of the present invention, a pulverized coal boiler system using low calorific value fuel gas is provided, which includes the above pulverized coal boiler apparatus, and further includes a synthesis process system, wherein the synthesis process system provides fuel gas for a fuel gas main pipe.

One or some of the above technical solutions have the following advantages or beneficial effects:

1) the utility model carries out boiler ignition through fuel gas, reduces the influence on the catalyst and the filter bag, saves the using amount of ignition diesel oil and reduces the production cost. The uncontrollable safety accident of the tail flue caused by insufficient combustion in the diesel ignition process is eliminated, and the economic benefit and the environmental protection benefit are obvious. The utility model carries out boiler ignition through fuel gas, avoids fire caused by diesel oil liquid drops entering a slag well water seal due to poor diesel oil nozzle atomization effect, reduces the probability of oil smoke in the flue gas entering an ammonia desulphurization device, avoids the phenomenon that the slurry of a desulphurization tower abnormally generates foam, improves the operation condition of a desulphurization system and prolongs the operation period of the desulphurization system.

2) The pulverized coal fired boiler furnace is designed into a four-corner burner structure, and the four-corner burner has the main advantages that four-corner flames are mutually supported, air mixing is convenient to control, and the burning adaptability is strong.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the utility model and, together with the description, serve to explain the utility model and not to limit the utility model.

FIG. 1 is a schematic diagram of a pulverized coal boiler plant in accordance with an embodiment of the present invention.

In the figure: 1. a fuel gas main; 2. a self-supporting regulator valve; 3. an air intake manual valve; 4. an intake valve; 5. a pneumatic quick-closing valve; 6. a flame arrestor; 7. a metal hose; 8. a boiler ignition layer burner; 9. a nitrogen purge valve; 10. a pulverized coal fired boiler hearth.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

In one or some embodiments of the present invention, a pulverized coal fired boiler device is provided, which includes a pulverized coal fired boiler furnace 10, boiler ignition layer burners 8 are disposed at four corners of the pulverized coal fired boiler furnace 10, and the boiler ignition layer burners 8 are supplied with combustion gas from a combustion gas header pipe 1.

The inventor analyzes that the four-corner burner mainly has the following advantages:

1) because most of the furnace chamber volume can be transversely swept by the rotating flame in the furnace, the furnace flame fullness of the four-corner tangential firing boiler is good;

2) compared with a cyclone burner, the rotary flame in the tangential firing boiler with four corners is beneficial to later-stage air-powder mixing, so that the burnout rate of the pulverized coal is high;

3) the temperature field in the furnace is distributed reasonably because the rotary flame is full of the whole hearth, and is not easy to generate local high temperature:

4) compare cyclone burner, the combustor arrangement mode of four corners tangential firing boiler is comparatively nimble, and fuel accommodation is wide, and distance and the export angle between each spout all can be adjusted.

5) Compared with a cyclone burner, the four-corner tangential firing boiler has strong capability of adapting to fuel change and load change. Because the coal quality of domestic power plants is variable and often participates in peak regulation, the four-corner tangential firing boiler can adapt to the change of fuel and load by adjusting the air quantity and the coal quantity of each nozzle.

In summary, the four-corner combustion furnace has the main advantages that the four-corner flames are mutually supported, the air mixing is convenient to control, and the combustion adaptability is strong, so that the four-corner combustion furnace is adopted as the pulverized coal boiler furnace 10, low-calorific-value gas is ignited from the boiler ignition layer combustor 8, the distribution of the furnace temperature field is reasonable because the rotary flames fill the whole furnace, and the local flameout phenomenon is avoided.

Preferably, the fuel gas main 1 is divided into four fuel gas branches, and each fuel gas branch corresponds to one boiler ignition layer burner 8. And each gas branch is provided with a valve for controlling the pressure and other parameters of the gas branch.

Preferably, a nitrogen gas pipe is further included, which supplies nitrogen gas to the boiler ignition layer burner 8. The nitrogen is doped with the combustion gas, so that the nitrogen plays a role in protection, and explosion caused by local uneven distribution of the combustion gas is avoided.

The nitrogen gas can be mixed with the combustion gas at the feed inlet of the boiler ignition layer burner 8 or before the fuel gas main 1, but preferably, the nitrogen gas pipeline corresponds to four nitrogen gas branches, and each nitrogen gas branch corresponds to one fuel gas branch. Four nitrogen gas branch roads, every nitrogen gas branch road corresponds a gas branch road can the maximum misce bene.

Preferably, the nitrogen pipeline comprises a nitrogen purge valve 9 for controlling the nitrogen to purge the fuel gas branch.

Preferably, a pneumatic quick-closing valve 5 is arranged on the gas branch.

Preferably, a flame arrester 6 is arranged on the gas branch. Flame arrestors are safety devices used to prevent the spread of flames of flammable gases and flammable liquid vapors. The device for preventing the passage of a propagating flame (deflagration or detonation), which is generally installed in a conduit for transporting combustible gases, or in a ventilated tank, consists of a flame-retardant core, a flame-retardant casing and accessories. Flame arrestors are also commonly used in pipelines for the transport of flammable gases. If flammable gases are ignited, the gas flame will propagate throughout the piping network. Therefore, the flame arrester is arranged on the gas branch, so that the gas can be prevented from being ignited and exploded in an emergency.

Preferably, an air inlet manual valve 5 and a self-supporting adjusting valve 2 are arranged between the contact points of the fuel gas main pipe 1 and each fuel branch, and the pressure of the fuel gas is controlled and adjusted to be stable.

In one or some embodiments of the utility model, a pulverized coal boiler system for igniting fuel gas with low calorific value is provided, which comprises the pulverized coal boiler device and a synthesis process system, wherein the synthesis process system is used for providing fuel gas for a fuel gas main pipe 1.

A large amount of low-heating-value fuel gas is usually generated in the synthesis process, the generated low-heating-value fuel gas is used for ignition, and meanwhile, the utilization of the low-heating-value fuel gas is realized.

Preferably, a coal feeder is further included to supply pulverized coal to the furnace 10 of the pulverized coal boiler.

In one or some embodiments of the present invention, there is provided a method of igniting a pulverized coal fired boiler apparatus, comprising the steps of:

taking pulverized coal fired boiler No. 1 corner as an example, ignition fuel gas is led to each corner of the boiler through a fuel gas main pipe 1, when the pressure of the fuel gas is adjusted to 50kPa by the self-supporting adjusting valve 2, the air inlet manual valve 3 and the air inlet valve 4 are opened, the high-energy ignition gun of the boiler ignition layer burner 8 is started firstly, then a pneumatic quick-closing valve 5 of a fuel gas pipeline is opened, the fuel gas passes through a flame arrester 6 and a metal hose 7, and the ignition is successful under the ignition energy of the ignition gun, the fire detection signal arranged in the boiler ignition layer burner 8 sends out a normal fire detection intensity signal after detecting the brightness of the fire source, the ignition is successful, when the fire detection signal is not available or the fire detection intensity is insufficient, an ignition failure signal is sent, the pneumatic quick-closing valve 5 is closed rapidly, the nitrogen purging valve 9 is opened for purging, the steps are repeated until all four corners of the boiler are successfully ignited, and the temperature rise condition of the hearth is monitored.

When the temperature of the hearth reaches a certain temperature and does not rise any more, adjusting the self-supporting adjusting valve 2 to increase the fuel gas pressure to 60kPa, continuing to heat the hearth, correspondingly adjusting the combustion air distribution of the boiler and the negative pressure of the hearth, starting the coal mill for warm grinding when the primary air temperature of the inlet of the coal mill is increased to 90 ℃ by the flue gas, starting the coal feeder for feeding coal when the primary air temperature of the inlet of the coal mill reaches 120 ℃, operating the coal feeder at the lowest load, and operating the coal mill according to the normal point furnace sequence after normal powder discharge.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, therefore, the present invention is not limited by the appended claims.

Claims

1. A pulverized coal boiler device is characterized by comprising a pulverized coal boiler hearth (10), boiler ignition layer burners (8) are arranged on four corners in the pulverized coal boiler hearth (10), the boiler ignition layer burners (8) supply combustion gas through a fuel gas main pipe (1), and an air inlet manual valve (5) and a self-supporting regulating valve (2) are arranged between the fuel gas main pipe (1) and contact points of fuel branches; the pulverized coal boiler device further comprises a nitrogen pipeline, the nitrogen pipeline supplies nitrogen to the boiler ignition layer burner (8), the nitrogen pipeline corresponds to four nitrogen branches, and each nitrogen branch corresponds to one fuel gas branch.

2. Pulverized coal fired boiler plant according to claim 1 characterized in that the fuel gas main (1) is divided into four gas branches, each gas branch corresponding to a boiler ignition layer burner (8).

3. Pulverized coal fired boiler plant according to claim 1 characterized in that the nitrogen line comprises a nitrogen purge valve (9) controlling the nitrogen purge to the gas branch.

4. Pulverized coal fired boiler plant as claimed in claim 2, characterized in that the gas branch is provided with a pneumatic quick-closing valve.

5. Pulverized coal fired boiler plant as claimed in claim 1, characterized in that flame arrestors (6) are provided in the gas branch.

6. A pulverized coal boiler system for igniting fuel gas with low calorific value, characterized in that it comprises the pulverized coal boiler device of any one of claims 1 to 5, and a synthesis process system, said synthesis process providing fuel gas for the fuel gas main (1).

7. The pulverized coal boiler system using low calorific value fuel gas as claimed in claim 6, further comprising a coal feeder for supplying pulverized coal to the furnace chamber (10) of the pulverized coal boiler.