Straight-flow combustor for combustion of low-heating-value gas

Abstract

The utility model discloses a straight-flow burner for burning low-calorific-value gas, which comprises a gas channel, one end of the gas channel is connected and communicated with one end of a nozzle, and both the gas channel and the nozzle are arranged in an air chamber; the nozzle comprises a plurality of mutually separated nozzles, the nozzles are respectively connected with the inner cavity of the ventilation chamber and the inner cavity of the gas channel, and the inner cavity of the gas channel is not communicated with the inner cavity of the ventilation chamber. By optimizing the structure of the burner, including optimizing the geometrical shape of the outlet of the burner, the gas and the air are distributed in the same nozzle in a staggered and separated manner, so that the resistance of the burner is reduced, the gas speed and the air speed of the outlet of the burner are optimized, the contact area of the gas and the air is larger, and the gas and the air are mixed more fully.

Description

Technical Field

[0001] The utility model relates to a direct-flow burner for burning low calorific value gas, belonging to the technical field of burners. Background Art

[0002] With the rapid development of my country's steel industry, the output of blast furnace gas and low calorific value gas produced in the metallurgical process has greatly increased, and the calorific value of blast furnace gas or low calorific value gas has become lower and lower. The average calorific value of blast furnace gas in 1965 was about 4180kJ / m3, and the average calorific value of blast furnace gas in 2006 has dropped to 3135kJ / m3. In addition to the mixed burning method, that is, mixing with coke oven gas or converter gas to increase the calorific value, about 50% is used in the internal process of steel enterprises, and nearly half of the blast furnace gas cannot be effectively used and is released. The released blast furnace gas not only pollutes the environment, but also wastes energy.

[0003] With the development of my country's chemical industry, various VOCS gases need to be treated urgently. If they are discharged directly, they will pollute the environment. If they are used as fuel, their calorific value is too low. Therefore, sending them to the boiler for combustion treatment is a very suitable choice.

[0004] Although the patent number CN200810033093 discloses a burner and a combustion method for pure blast furnace gas or low calorific value gas, and proposes a swirl combustion method and a specific structure, it is not applicable to direct current burners such as the four-corner tangential combustion method. Summary of the invention

[0005] The technical problem to be solved by the utility model is: for direct current burners such as four-corner tangential combustion mode, how to effectively utilize blast furnace gas and avoid its dispersion.

[0006] In order to solve the above technical problems, the technical solution of the utility model is to provide a direct-flow burner for combustion of low calorific value gas, characterized in that it includes a gas channel, one end of the gas channel is connected and connected to one end of the nozzle, and the gas channel and the nozzle are both arranged in the wind chamber; the nozzle includes a plurality of nozzles separated from each other, the nozzles are respectively connected to the inner cavity of the ventilation chamber and the inner cavity of the gas channel, and the inner cavity of the gas channel is not connected to the inner cavity of the wind chamber.

[0007] Preferably, the nozzles connected to the inner cavity of the ventilation chamber and the nozzles connected to the inner cavity of the gas passage are arranged alternately and spaced apart.

[0008] Preferably, the inner cavity of the gas channel is isolated from the inner cavity of the wind chamber and is not pre-mixed.

[0009] Preferably, the nozzle is a direct-flow spraying structure.

[0010] Preferably, the nozzle and the combustion chamber are sealed and connected via a sealing plate.

[0011] A combustion method of a direct current burner for low calorific value gas combustion, characterized in that a direct current burner for low calorific value gas combustion is used, a four-corner tangential circle combustion method is adopted, a gas outlet velocity is 22-30m / s, and an air outlet velocity is 40-57m / s.

[0012] Preferably, the nozzle gas resistance is no higher than 1 kPa, and the air resistance is no higher than 1.2 kPa.

[0013] Preferably, an ignition device is arranged below the direct-flow burner, or an ignition device is arranged on the side of the direct-flow burner, or no ignition device is arranged.

[0014] Preferably, the calorific value of the low calorific value gas is less than 6280 KJ / Nm3.

[0015] Compared with the prior art, the utility model has at least one of the following beneficial effects:

[0016] The utility model has a simple structure and is applied to burners of four-corner tangential combustion technology. By optimizing the structure of the burner, including optimizing the geometric shape of the burner outlet, typical swirl structures such as swirl blades and central nozzles are eliminated, and at the same time optimized to a direct-flow type gas and air staggered arrangement. The gas (coal gas) and air are arranged in a staggered and separated manner in the same nozzle, which reduces the burner resistance, optimizes the outlet gas velocity and air velocity of the burner, makes the contact surface between the gas and the air larger, and makes the mixing more complete, and strengthens the gas combustion, so as to achieve a direct-flow type airflow structure suitable for the four-corner tangential combustion technology, and make the air distribution strategy of the four-corner tangential combustion combustion system more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a direct-flow burner for combustion of low calorific value gas;

[0018] Figure 2 A schematic diagram of the nozzle connected to the gas channel;

[0019] Figure 3 This is a partial diagram of the burner of a 1133t / h supercritical pressure once-through boiler in a steel plant;

[0020] Figure 4 This is a partial view of a burner in a power plant. DETAILED DESCRIPTION

[0021] In order to make the present invention more obvious and easy to understand, preferred embodiments are described in detail as follows in conjunction with the accompanying drawings.

[0022] The utility model provides a direct-flow burner for low calorific value gas combustion, which is used in power station boilers and has strong stable combustion and full combustion capabilities, such as Figure 1 , Figure 2 As shown, it is composed of a wind chamber 1, a gas channel 2, a nozzle 3, and a sealing plate 4. The gas channel 2 is connected to the nozzle 3, and the nozzle 3 is connected to the wind chamber 1 through the sealing plate 4. The coal gas A (i.e., gas) in the gas channel 2 and the air B in the wind chamber 1 are both ejected in a straight-flow manner through the nozzle 3 (the coal gas A and the air B are ejected through multiple nozzles of the nozzle 3 respectively, and each nozzle only corresponds to the wind chamber 1 or the gas channel 2), and each nozzle for ejecting coal gas A and each nozzle for ejecting air B are staggered and spaced from each other. The coal gas A (i.e., gas) in the gas channel 2 and the air B in the wind chamber 1 are isolated by the outer wall of the gas channel 2, and are not pre-mixed in the wind chamber 1. The sealing plate 4 seals the nozzle 3 and the wind chamber 1 to ensure that the wind in the wind chamber 1 is ejected only through the nozzle of the nozzle 3, and no peripheral wind is set.

[0023] A combustion method of a direct-flow burner for low calorific value gas combustion, adopting a four-corner tangential combustion method, with a gas A outlet velocity of 22-30m / s and an air B outlet velocity of 40-57m / s. The gas nozzle resistance does not exceed 1kpa, and the air nozzle resistance does not exceed 1.2kpa. An ignition device can be set below the direct-flow burner, or an ignition device can be set on the side of the direct-flow burner, or no ignition device can be set. The calorific value of the low calorific value gas should be less than 6280KJ / Nm3.

[0024] The 1133t / h supercritical pressure direct current boiler of a steel plant is designed to use bituminous coal as fuel, and can also burn 0-200,000 Nm3 / h blast furnace gas. The blast furnace gas burner adopts the "direct current burner and combustion method for low calorific value gas combustion" proposed in this utility model. The blast furnace gas burner is arranged below the pulverized coal burner, and an ignition device is arranged between the two layers of blast furnace gas burners. A partial diagram of the burner is shown in the figure below. Figure 3 shown.

[0025] A power plant was transformed to burn biomass, and adopted the "a direct-flow burner and combustion method for low calorific value gas combustion" proposed in the utility model, but no ignition device was set. Figure 4 shown.

Claims

1. A direct-flow burner for combustion of low calorific value gas, characterized in that: The invention comprises a gas channel (2), one end of the gas channel (2) is connected and communicated with one end of a nozzle (3), and the gas channel (2) and the nozzle (3) are both arranged in a wind chamber (1); the nozzle (3) comprises a plurality of nozzles separated from each other, and the plurality of nozzles are respectively connected to the inner cavity of the ventilation chamber (1) and the inner cavity of the gas channel (2), and the inner cavity of the gas channel (2) is not communicated with the inner cavity of the wind chamber (1).

2. A through-flow burner for combustion of low calorific value gas according to claim 1, characterized in that: The inner cavity of the gas channel (2) is isolated from the inner cavity of the wind chamber (1).

3. A direct-flow burner for combustion of low calorific value gas according to claim 1, characterized in that: The nozzles connected to the inner cavity of the air chamber (1) and the nozzles connected to the inner cavity of the gas channel (2) are arranged in a staggered manner.

4. A direct-flow burner for combustion of low calorific value gas as claimed in claim 1, characterized in that: The nozzle (3) is a direct-flow spraying structure.

5. A through-flow burner for combustion of low calorific value gas as claimed in claim 1, characterized in that: The nozzle (3) and the wind chamber (1) are sealed and connected via a sealing plate (4).

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