CN201507924U - A double-sided ignition combination blunt body micro-oil ignition burner - Google Patents

Abstract

The utility model discloses a double-sided ignition combination blunt body micro-oil ignition burner. The pulverized coal concentrator formed by the variable diameter pipe formed by the throat of the primary air duct is indented through a section and communicates with the pulverized coal combustion chamber of the secondary pulverized coal. The chamber extends into the three-stage pulverized coal combustion chamber. The upper and lower sides of the third-stage pulverized coal combustion chamber connected to the second-stage pulverized coal combustion chamber have multiple secondary air inlets, and the upper and lower oil combustion chambers pass obliquely through the secondary pulverized coal combustion chamber. On the first-stage pulverized coal combustion chamber, the port of the secondary pulverized coal combustion chamber is equipped with a combination blunt body, and the secondary pulverized coal combustion chamber located in the third-stage pulverized coal combustion chamber is provided with a plurality of flow holes above and below. Double oil guns are arranged up and down to realize double-sided ignition of the pulverized coal entering the first-stage pulverized coal combustion chamber, enhance the turbulence and heat exchange between the pulverized coal airflow and the oil flame, rapidly heat the pulverized coal, and form a fire curtain to prolong the life of the coal. powder residence time; thereby enhancing the ignition process.

Description

A double-sided ignition combination blunt body micro-oil ignition burner

technical field

The utility model relates to a pulverized coal burner, in particular to a double-sided ignition combination blunt body micro-oil ignition burner.

Background technique

The micro-oil ignition and combustion-supporting technology can realize the boiler ignition with a small amount of oil when the boiler is cold-started, and use a small amount of oil to stabilize the boiler combustion when the boiler is shut down, low load and ultra-low load. This combustion technology is generally When used in high volatile coal, the fuel saving effect can generally reach more than 90%. But for anthracite and lean coal with low volatile content, it can only achieve about 60% fuel-saving effect, and its application is greatly limited. In the past, the micro-oil ignition burner generally adopted the method of arranging oil guns on one side, so the heating of the pulverized coal was heated on one side; this resulted in a long heating time and required a longer size of the entire pulverized coal burner. This is difficult for most power plants, so how to complete the ignition and combustion process of pulverized coal within a short distance is a problem that must be faced when using low-volatile coal. Solve this problem, can proceed from two aspects: the one, increase the contact cheek of flame and pulverized coal to the greatest extent, the 2nd, prolong the contact time of pulverized coal and flame, just prolong the residence time of pulverized coal in the burner. The utility model proposes a reasonable solution in these two aspects.

Contents of the invention

The purpose of the utility model is to provide a double-sided ignition combined blunt body micro-oil ignition burner, which adopts a square nozzle and can burn low-volatile coal types and has a good fuel-saving effect.

In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is:

It includes a rectangular cross-section primary air channel, a pulverized coal concentrator, a primary pulverized coal combustion chamber, a secondary pulverized coal combustion chamber and a tertiary pulverized coal combustion chamber, which are connected in sequence and whose central axes coincide. The pulverized coal concentrator formed by the variable diameter pipe forming the throat communicates with the secondary pulverized coal combustion chamber, the primary pulverized coal combustion chamber is installed in the secondary pulverized coal combustion chamber, and the secondary pulverized coal combustion chamber extends into the combustion chamber. The upper and lower sides of the third-stage pulverized coal combustion chamber connected to the second-stage pulverized coal combustion chamber have multiple secondary air inlets, and the upper and lower oil combustion chambers pass obliquely through the secondary pulverized coal combustion chamber. On the first-stage pulverized coal combustion chamber, the port of the second-stage pulverized coal combustion chamber is equipped with a combination blunt body, and the secondary pulverized coal combustion chamber located in the third-stage pulverized coal combustion chamber is provided with a plurality of flow holes above and below.

The combined blunt body is composed of three blunt bodies. The upper and lower blunt bodies are regular hexahedrons with a right-angled trapezoidal cross-section, which are symmetrically arranged at the outlet of the secondary pulverized coal combustion chamber. The middle blunt body is a regular tetrahedron with a triangular cross-section. body, its position is on the main axis of the burner, and the middle blunt body protrudes from the upper and lower blunt bodies.

The beneficial effect that the utility model has is:

The double oil guns are arranged up and down, which can realize double-sided ignition of the pulverized coal entering the first-level pulverized coal combustion chamber, which enhances the turbulence and heat exchange between the pulverized coal airflow and the oil flame, rapidly heats the pulverized coal, and forms a fire curtain. It can prolong the residence time of pulverized coal to a certain extent; thereby strengthening the ignition process.

The function of several circular holes on the wall of the secondary combustion chamber is to use the characteristic that the secondary air pressure is greater than the primary air pressure, so that part of the secondary air passes through the small holes and enters the secondary combustion chamber to form a jet, which prevents it from entering the secondary air. The action of the light pulverized coal airflow in the combustion chamber pushes it to the middle, which will greatly strengthen the mixing and heat transfer between it and the high-temperature airflow from the primary combustion chamber, and accelerate the ignition process of the light coal pulverized airflow. The secondary air can also supplement the air needed for combustion, and partially compensate for the impact on combustion caused by insufficient air volume in the primary air. The existence of the group and the blunt body further prolongs the residence time of the pulverized coal in the burner, and forms a strong mixing disturbance in the three-stage combustion chamber, and maintains a stable high-temperature recirculation zone behind the blunt body, thereby improving the ignition conditions and improving the ignition efficiency. stability. The micro-oil ignition pulverized coal burner provided by the utility model can be used not only as an ignition burner, but also as a main burner and a low-load stable combustion burner.

Description of drawings

Fig. 1 is a schematic diagram of the longitudinal section structure of the micro-oil ignition pulverized coal burner of the utility model.

Fig. 2 is a left sectional view of Fig. 1 .

Fig. 3 is a right sectional view of Fig. 1 .

In the figure: 1. Primary air channel, 2. Pulverized coal concentrator, 3. Oil combustion chamber, 4. Primary pulverized coal combustion chamber, 5. Secondary pulverized coal combustion chamber, 6. Combined blunt body, 7. Tertiary Pulverized coal combustion chamber, 5.1, flow hole, 6.1, lower blunt body, 6.2, middle blunt body, 6.3, upper blunt body, 7.1, secondary air inlet, 7.2, secondary air channel.

Detailed ways

Below in conjunction with accompanying drawing, the specific embodiment of the present utility model is described in further detail.

As shown in Figure 1 and Figure 2, the utility model includes a primary air channel 1 with a rectangular cross-section, a pulverized coal concentrator 2, a pulverized coal combustion chamber 4, and a pulverized coal combustion chamber 6, which are successively connected and whose central axes coincide. and the third-stage pulverized coal combustion chamber 7; the pulverized coal concentrator 2 formed by the variable-diameter pipe of the throat formed by the primary air duct 1 communicates with the secondary pulverized coal combustion chamber 5, and the primary pulverized coal combustion chamber 4 is installed In the secondary pulverized coal combustion chamber 5, the secondary pulverized coal combustion chamber 5 extends into the tertiary pulverized coal combustion chamber 7. The third-stage pulverized coal combustion chamber 7 connected to the secondary pulverized coal combustion chamber 5 has multiple secondary air inlets 7.1 on the upper and lower sides, and the upper and lower two oil combustion chambers 3 obliquely pass through the secondary pulverized coal combustion chamber. After the chamber 5 is installed on the first-level pulverized coal combustion chamber 4, the 5 ports of the secondary pulverized coal combustion chamber are installed with a combined blunt body 6, and the secondary pulverized coal combustion chamber 5 located in the third-level pulverized coal combustion chamber 7 is equipped with a Multiple flow holes 5.1.

The upper and lower sides of the first-stage combustion chamber are symmetrically equipped with a variable-section oil combustion chamber, and its axis line forms an obtuse angle with the main axis of the burner (positive direction at the exit).

The cross-sectional shape of the variable-section oil combustion chamber gradually changes from circular at the inlet to waist-circular at the outlet.

The secondary pulverized coal combustion chamber is an extension of the primary air passage, and on the upper and lower walls near the exit of the primary combustion chamber, several flow holes are opened at equal distances, so that the secondary combustion chamber and the secondary air passage connected.

The section width of the third-stage pulverized coal combustion chamber is equal to the section width of the secondary pulverized coal combustion chamber, and the section height is greater than the section height of the secondary combustion chamber; wind channel. On the upper and lower walls connecting the third-stage pulverized coal combustion chamber and the second-stage pulverized coal combustion chamber, several rectangular holes are respectively opened as secondary air inlets.

As shown in Figures 1 and 3, the combined blunt body 6 is composed of three blunt bodies, the upper and lower blunt bodies 6.1 and 6.3 are regular hexahedrons with a right-angled trapezoidal cross section, and are symmetrically arranged at the outlet of the secondary pulverized coal combustion chamber. , the middle blunt body 6.2 is a regular tetrahedron with a triangular cross-sectional shape, its position is on the main axis of the burner, and the middle blunt body 6.2 protrudes from the upper and lower blunt bodies.

Situation during actual work of the micro-oil ignition pulverized coal burner of the present utility model is as follows:

The primary air carries pulverized coal into the primary air channel 1, and when passing through the concentrator 2, the pulverized coal airflow is concentrated. According to the principle of inertia, when the flow section of the pulverized coal flow suddenly expands, the dense pulverized coal flow will maintain inertia and concentrate into the primary combustion chamber 4, while the light pulverized coal flow will deflect from the upper and lower ends of the primary and secondary combustion chambers. The gap in the middle of the chamber bypasses the oil combustion chamber and enters the secondary combustion chamber 6. The oil flame sprayed from the oil combustion chamber 3 will directly scour the dense pulverized coal flow on the upper and lower sides of the pulverized coal flow, forming a violent mass transfer and heat transfer process, so that the pulverized coal will heat up rapidly and burn; the high temperature product flows through the first stage At the outlet of the combustion chamber, it meets the mixture of the secondary air and the light pulverized coal flow passing through the flow hole 5.1, forming a violent mixing and disturbance process. Continuing to burn and release heat, on the other hand, will greatly shorten the ignition time of the light coal powder flow and accelerate the combustion process. The combustion products and unburned coal powder in the secondary combustion chamber will meet the group and the blunt body when they reach the outlet, and the airflow will pass through the upper and lower sides and the middle of the blunt body 6.1, 6.3, and the airflow passing through the middle will encounter the blunt body. 6.2 of the blunt body produces split flow. As a result, three stable high-temperature recirculation zones will be formed at the back of the blunt body and the blunt body, which will play a key role in strengthening the mixing and disturbance of the air flow and enhancing the heat transfer and mass transfer process. In addition, the blunt body The presence of solids will also prolong the residence time of the gas-powder mixture in the combustion chamber, which is conducive to the ignition and combustion of low-volatile coal types. Pass through the combined blunt body and enter the mixture of the third-stage combustion chamber 7, including combustion products and unburned coal powder, because the air volume in the primary air pulverized coal airflow is generally about 15% to 40% of the total air volume, so , in order to maximize the combustion and heat release of pulverized coal, the secondary air must be supplemented. The effect of the tertiary combustion chamber is exactly to pass into the secondary air to accelerate the combustion and burnout of pulverized coal. The secondary air enters the secondary air channel 7.2 from the inlet 7.1, and then enters the tertiary combustion chamber 7, where it meets the mixture diverted from the blunt bodies 6.1 and 6.3 at the entrance of the tertiary combustion chamber. Due to the difference in speed between the two and the blunt body The bias flow effect of 6.1 and 6.3 causes the airflow to generate violent mixing and disturbance again to complete the subsequent combustion process, and finally the high-temperature flue gas is sprayed into the furnace from the outlet of the third-stage combustion chamber.

Finally, it should also be noted that what is listed above is only a specific embodiment of the present invention. Apparently, the utility model is not limited to the above embodiments, and many variations are possible. All deformations that a person skilled in the art can derive or associate directly from the content disclosed in the utility model shall be considered as the protection scope of the utility model.

Claims (2)

1. A double-sided ignition combined blunt body micro-oil ignition burner, comprising a rectangular cross-section primary air passage (1), a pulverized coal concentrator (2), and a pulverized coal combustion chamber ( 4), the secondary pulverized coal combustion chamber (6) and the tertiary pulverized coal combustion chamber (7); the pulverized coal concentrator (2) composed of a variable-diameter pipeline at the throat formed by the primary air duct (1) Connected with the secondary pulverized coal combustion chamber (5), the primary pulverized coal combustion chamber (4) is installed in the secondary pulverized coal combustion chamber (5), and the secondary pulverized coal combustion chamber (5) extends into the tertiary pulverized coal combustion chamber In the combustion chamber (7); it is characterized in that: the upper and lower sides of the third-stage pulverized coal combustion chamber (7) connected with the secondary pulverized coal combustion chamber (5) have a plurality of secondary air inlets (7.1) separately, and the upper , The lower two oil combustion chambers (3) obliquely pass through the secondary pulverized coal combustion chamber (5) and are installed on the primary pulverized coal combustion chamber (4), and the ports of the secondary pulverized coal combustion chamber (5) are installed with blunt Body (6), located on the secondary pulverized coal combustion chamber (5) in the third-stage pulverized coal combustion chamber (7), has a plurality of flow holes (5.1) below. 2. A double-sided ignition combined blunt body micro-oil ignition burner according to claim 1, characterized in that: the combined blunt body (6) is composed of three blunt bodies, the upper and lower (6.1, 6.3 ) blunt body is a regular hexahedron with a right-angled trapezoidal cross-section, which is symmetrically arranged at the outlet of the secondary pulverized coal combustion chamber. The blunt body (6.2) protrudes from the upper and lower blunt bodies.

Images