CN201159452Y - Once-through Boiler Adaptive Ignition Burner - Google Patents

Abstract

The utility model discloses an adaptive ignition burner for a once-through boiler. The burner is located at the lower part of the furnace. The outlet of the coal mill is connected with a fine powder three-way valve, and the fine powder three-way valve communicates with the outer primary air duct and the inner primary air duct through the first fine powder pipe and the second fine powder pipe respectively; it is parallel to the main pulverizer There is an auxiliary coal mill, and the outlet of the auxiliary coal mill is connected with a three-way valve for ultrafine powder, which passes through the first ultrafine powder pipe and the second ultrafine powder pipe and the primary air auxiliary pipe respectively. It communicates with the primary wind supervisor. The utility model has a simple structure, realizes separate combustion of coarse and fine coal powder, greatly improves the stability of boiler ignition and low-load operation, saves fuel, reduces power generation costs, and also has the advantages of anti-coking and wide adaptability of coal types.

Description

Once-through Boiler Adaptive Ignition Burner

technical field

The utility model belongs to the technical field of ignition and combustion devices for thermal power generation, in particular to an adaptive ignition burner for once-through boilers used for ignition of boilers in thermal power plants.

Background technique

As a large consumer of fuel oil, thermal power plants consume a large amount of fuel oil for boiler ignition and stable combustion every year. According to the data from the Development and Reform Commission, the annual fuel consumption of my country's generator sets is as high as 7.6 million tons, equivalent to 41.8 billion yuan. my country is an oil-poor country. In 2004, the oil consumption was 317 million tons, the domestic production was 176 million tons, the net import was 151 million tons, and the foreign dependence reached 47.3%. Therefore, reducing the fuel consumption of power generation is of great significance for reducing the cost of power generation, improving the economic benefits of power generation enterprises and my country's energy security strategy.

In 2005, the country launched the "Medium and Long-term Special Plan for Energy Conservation", and put forward the goal of saving and replacing 38 million tons of oil during the "Eleventh Five-Year Plan" period. In order to reduce the cost of power generation and achieve the goal of saving fuel, it is the most urgent need for power plants to develop and install new fuel-saving boiler ignition and combustion technology. At present, the ignition and combustion devices of most coal-fired power plants in my country mainly include a main coal mill, a primary air duct, a burner and a furnace. The outlet of the outlet is connected to the burner, the burner is located at the lower part of the furnace, the burner is composed of an outer primary air pipe and an oil gun, wherein the oil gun is located on the main axis of the outer primary air pipe, and the nozzle of the oil gun is close to the outer The outlet of the primary air pipe; and a circle of bosses are arranged on the inner wall of the outlet section of the outer primary air pipe near the nozzle of the oil gun as a pulverized coal concentrator. At the initial stage of ignition, the oil gun sprays a large amount of fuel oil into the furnace, and after the oil is heated for a period of time, the pulverized coal is sprayed out through the primary air pipe and the outlet of the primary air pipe outside the burner, and the pulverized coal is burned outside the outlet. After the combustion is stable, turn off the oil circuit of the oil gun. However, the quality of coal fired in power stations in my country generally deviates and fluctuates greatly.

If the pulverized coal is too coarse, it will be difficult to achieve full combustion at the initial stage of ignition, and a large amount of fuel oil will be consumed, which will greatly increase the fuel consumption; Tube explosion on the heating surface affects the safe operation of the power plant.

Disadvantages of the existing once-through boiler combustion device: in the initial stage of ignition and low-load operation of the boiler in the power plant, the combustion is unstable and the fuel consumption is large; when the boiler is in stable operation, the heating surface in the burner and near the outlet is easy to coke.

Utility model content

Aiming at the problems existing in the prior art, the purpose of this utility model is to provide a method that can realize the separation and combustion of coarse and fine pulverized coal, which can not only save fuel at the initial stage of ignition and combustion and during low-load operation, but also prevent coking and reduce the Adaptive ignition burners for once-through boilers for thermal power generation.

In order to achieve the above object, the technical scheme of the utility model is as follows:

An adaptive ignition burner for a once-through boiler, including a main coal mill, a primary air main pipe, a burner and a furnace, wherein the burner is located at the lower part of the furnace. Composed of air duct and oil gun, the oil gun is located on the main axis of the inner primary air duct, and the nozzle of the oil gun is close to the outlet of the inner primary air duct; the inner primary air duct is located on the main axis of the outer primary air duct, and the inner primary air duct The outlet of the pipe is close to the outlet of the outer primary air pipe; the oil gun passes through the primary air secondary pipe and the primary air main pipe, and the oil pipe is connected to the tail of the oil gun;

The outlet of the main coal mill is connected with a fine powder three-way valve, and the fine powder three-way valve communicates with the primary air main pipe and the primary air auxiliary pipe through the first fine powder pipe and the second fine powder pipe respectively. The primary air main pipe communicates with the outer primary air pipe, and the primary air secondary pipe communicates with the inner primary air pipe; an auxiliary coal mill is arranged side by side with the main coal mill, and the outlet of the auxiliary coal mill is connected with an ultrafine powder A three-way valve, the ultrafine powder three-way valve communicates with the primary air secondary pipe and the primary air main pipe through the first ultrafine powder pipe and the second ultrafine powder pipe respectively.

According to the different operating conditions of the boiler, the switching of the fine powder three-way valve and the ultra-fine powder three-way valve is respectively controlled, and the specific operations are as follows:

When the boiler is ignited, operated at low load, and the coal quality is deviated, fine coal powder and ultra-fine coal powder pass through the first fine powder tube and the first ultra-fine powder tube respectively, and then pass through the outer primary air duct and the inner primary air duct of the burner respectively. The air pipe is sprayed into the furnace, which is helpful for ignition and stable combustion, effectively reducing the fuel consumption for ignition and stable combustion, and saving fuel; The ultra-fine powder pipe is sprayed into the furnace from the inner primary air pipe and the outer primary air pipe respectively, thereby delaying the ignition of pulverized coal and preventing coking of the heating surface in and around the burner.

The furnace is also connected with a secondary air pipe, and the outlet of the secondary air pipe is located above the burner.

Fans are installed at the inlets of the primary air main pipe, primary air secondary pipe and secondary air pipe to communicate with the atmosphere.

The secondary air pipe sends oxygen into the furnace to promote the full combustion of pulverized coal in the furnace.

A ring of bosses is arranged on the inner wall near the outlet of the inner primary air pipe near the nozzle of the oil gun.

As a pulverized coal concentrator, the boss separates the pulverized coal in the inner primary air duct from thick to thin, so that the concentrated pulverized coal burns in the central area of the outlet of the outer primary air duct, which is easy for the pulverized coal to ignite and burn stably.

Beneficial effects: the utility model has a simple structure, can realize the separation and combustion of coarse and fine coal powder, greatly improves the stability of boiler ignition and low-load operation, saves fuel at the initial stage of ignition and combustion and low-load operation, and prevents boilers from burning during stable operation. Coking, reducing the cost of thermal power generation, and having the characteristics of wide adaptability to coal types, etc., can realize fuel-saving ignition, stable combustion, and optimized combustion according to coal types and operating conditions, and can adapt to low-oil ignition and stable combustion.

Description of drawings

Fig. 1 is the system schematic diagram of the present utility model;

Figure 2 is a schematic diagram of the structure of the burner.

Detailed ways

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

As shown in Figures 1 and 2, a once-through boiler adaptive ignition burner consists of a main coal mill 1, an auxiliary coal mill 1', a primary air main pipe 2, a primary air auxiliary pipe 2', a burner 11, and a furnace 4 , the first fine powder tube 5, the second fine powder tube 5', the fine powder three-way valve 7, the ultra-fine powder three-way valve 8, the first ultra-fine powder tube 6, the second ultra-fine powder tube 6', the outer one Composed of air duct 12 and inner primary air duct 12', wherein the burner 11 is located at the lower part of the furnace 4, and the burner 11 is composed of the outer primary air duct 12, the inner primary air duct 12' and the oil gun 3, wherein the oil gun 3 is located on the main axis of the inner primary air duct 12', and the nozzle of the oil gun 3 is close to the outlet of the inner primary air duct 12'; the inner primary air duct 12' is located on the main axis of the outer primary air duct 12, and the inner primary The outlet of the air pipe 12' is close to the outlet of the outer primary air pipe 12; the oil gun 3 passes through the primary air secondary pipe 2' and the primary air main pipe 2, and the tail of the oil gun 3 is connected with an oil pipe 13;

A support is welded between the outer primary air pipe 12 and the internal primary air pipe 12', and a support is welded between the internal primary air pipe 12' and the oil gun 3.

The outlet of the main coal mill 1 is connected with a fine powder three-way valve 7, and the fine powder three-way valve 7 is connected to the primary air main pipe 2 and primary air through the first fine powder pipe 5 and the second fine powder pipe 5' respectively. The auxiliary air pipe 2' communicates, the primary air main pipe 2 communicates with the outer primary air pipe 12, and the primary air auxiliary pipe 2' communicates with the inner primary air pipe 12'; Coal mill 1', the outlet of the auxiliary coal mill 1' is connected with an ultrafine powder three-way valve 8, and the ultrafine powder three-way valve 8 passes through the first ultrafine powder pipe 6 and the second ultrafine powder pipe 6 respectively. ' communicates with primary air secondary pipe 2' and primary air main pipe 2.

According to the different operating conditions of the boiler, the switching of the fine powder three-way valve 7 and the ultrafine powder three-way valve 8 is respectively controlled, and the specific operations are as follows:

When the boiler is ignited and started, low load operation, and coal quality deviation, the fine coal powder and ultra-fine coal powder pass through the first fine powder pipe 5 and the first ultra-fine powder pipe 6 respectively, and then pass through the outer primary air pipe 12 of the burner respectively. 1. The inner primary air pipe 12' is sprayed into the furnace 4, which is helpful for ignition and stable combustion, effectively reducing the oil used for ignition and stable combustion, and saving fuel; The fine powder pipe 5' and the second superfine powder pipe 6' are sprayed into the furnace 4 from the inner primary air pipe 12' and the outer primary air pipe 12 respectively, so as to delay the ignition of coal powder and prevent coking of the heating surface in and around the burner .

The furnace 4 is also connected with a secondary air pipe 9 , and the outlet of the secondary air pipe 9 is located above the burner 11 .

The inlet of described primary air main pipe 2, primary air secondary pipe 2 ' and secondary air pipe 9 is equipped with blower fan and communicates with atmosphere.

The secondary air pipe 9 sends oxygen into the furnace 4 to promote the full combustion of pulverized coal in the furnace 4 .

A circle of bosses 10 are arranged on the inner wall near the outlet of the inner primary air pipe 12 ' of the nozzle of the oil gun 3 .

The boss 10, as a pulverized coal concentrator, separates the pulverized coal in the inner primary air duct 12' from thick and thin, so that the thick pulverized coal is concentrated in the central area of the outlet of the outer primary air duct 12 for combustion, which is easy for the pulverized coal to ignite and burn stably.

Its working principle is: when the boiler is ignited, operated at low load, and the coal quality deviates, by adjusting the fine powder three-way valve 7 and the ultrafine powder three-way valve 8, the main coal mill 1 and the auxiliary coal mill 1' are respectively Connected with the first fine powder pipe 5 and the first ultrafine powder pipe 6, the fine coal powder and ultrafine coal powder are sprayed into the furnace through the outer primary air pipe 12 and the inner primary air pipe 12' of the burner; after the combustion is stable, the The main coal mill 1 and the auxiliary coal mill 1' communicate with the second fine powder pipe 5' and the second ultrafine powder pipe 6' respectively, and the fine coal powder and ultrafine coal powder pass through the inner primary air pipe 12' of the burner , The outer primary air pipe 12 is sprayed into the furnace.

Claims (3)

1. An adaptive ignition burner for a once-through boiler, comprising a main coal mill (1), a primary air main pipe (2), a burner (11) and a furnace (4), wherein the burner (11) is located in the furnace ( 4), it is characterized in that: the burner (11) is composed of an outer primary air pipe (12), an inner primary air pipe (12') and an oil gun (3), wherein the oil gun (3) is located in the inner primary air pipe on the main axis in the pipe (12'), and the nozzle of the oil gun (3) is close to the outlet of the inner primary air duct (12'); the inner primary air duct (12') is located on the main shaft in the outer primary air duct (12) On the line, the outlet of the inner primary air pipe (12') is close to the outlet of the outer primary air pipe (12); the oil gun (3) passes through the primary air secondary pipe (2') and the primary air main pipe (2), The tail of the gun (3) is connected with an oil pipe (13); The outlet of the main coal mill (1) is connected with a fine powder three-way valve (7), and the fine powder three-way valve (7) passes through the first fine powder pipe (5) and the second fine powder pipe (5' respectively). ) communicates with the primary air main pipe (2) and the primary air secondary pipe (2 '), the primary air primary pipe (2) communicates with the outer primary air pipe (12), and the primary air secondary pipe (2 ') communicates with the primary air secondary pipe (2') The inner primary air duct (12') communicates; an auxiliary coal mill (1') is arranged side by side with the main coal mill (1), and the outlet of the auxiliary coal mill (1') is connected with a superfine powder tee Valve (8), the superfine powder three-way valve (8) passes through the first superfine powder pipe (6) and the second superfine powder pipe (6') and the secondary air pipe (2') and the primary air main pipe respectively. (2) Communicate. 2. The self-adaptive ignition burner for a once-through boiler according to claim 1, characterized in that: the furnace (4) is also connected with a secondary air pipe (9), and the outlet of the secondary air pipe (9) is located at the above the burner (11). 3. The once-through boiler self-adaptive ignition burner according to claim 1, characterized in that: a circle of bosses ( 10).

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