CN102734827A - Grate-fired furnace air chamber structure capable of transversely uniformly distributing air - Google Patents

Abstract

An air chamber structure for uniform horizontal air distribution of a floor-burning furnace, including two lower partitions installed inside the air chamber of the floor-burning furnace, the height of the first lower partition is H1=b+(0.50~0.65)x, and the separation layer The distance of the air inlet of the furnace air chamber is S1=(0.25~0.30)L; the height of the second lower partition is H2=b+(0.8~1.0)x, and the distance from the first lower partition is S2=(0.30~ 0.35) L, where the distance between the bottom of the air chamber of the b-layer furnace and the lower part of the air inlet, x is the height of the air inlet, and L is the length of the air chamber of the layer burner. The feature of the present invention is: Aiming at the uniform horizontal air distribution of the layer combustion furnace, a set of air chamber structure design parameters with good flow equalization effect is proposed, which ensures the good air distribution uniformity of the air chamber and controls the resistance in a small range It creates conditions for improving the operating efficiency of the layer combustion furnace and reducing heat loss.

Description

An air chamber structure with uniform horizontal air distribution for a layer-burning furnace

technical field

The invention belongs to the air distribution device in the technical field of power engineering, and in particular relates to an air chamber structure for improving the uniform horizontal air distribution of an air-inlet layer combustion furnace.

Background technique

my country's industrial boilers are widely used. According to the data from the National Bureau of Statistics and the Bureau of Special Equipment, by the end of 2010, the total number of boilers in the country exceeded 600,000, and more than half of them were fired furnaces. The design efficiency of industrial boilers in my country is generally only 1% to 3% lower than that of developed countries, but the operating efficiency is more than 10% lower. The main reasons for the low operating efficiency and large heat loss of the floor-burning furnace are the unreasonable air distribution and poor adaptability of the floor-burning furnace. The existing layer-fired furnace generally has the problem of uneven horizontal air distribution, which increases the heat loss of chemical and mechanical incomplete combustion, and the problem is even more serious when the layer-fired furnace is operated under non-rated conditions. The typical performance of the uneven air distribution of the layer-fired furnace is that the burner is easy to appear in the strong ventilation area of the grate, and the combustion is incomplete in the weak ventilation area, and the carbon content of the slag is high. In the 1970s and 1980s, domestic researchers conducted experiments and theoretical studies on the problem of horizontal uniformity of air distribution in bed-burning furnaces. They mainly adopted the measures of double-side air intake and the installation of flow equalization baffles, but they did not completely solve this problem, especially for the improvement of single-side air-inlet layer burners. There is no complete set of methods to For design and modification.

In order to make the structure simple, many single-side air-intake layer-burning furnaces, especially small-scale layer-burning furnaces, do not have a flow-balancing partition in the air chamber. For the air chamber of the single-layer combustion furnace without a flow equalizing partition, there is obvious backflow in the air chamber, and the flow is complicated. The side burns incompletely. Due to the high speed and high dynamic pressure at the inlet of the air chamber, the airflow blocked by the grate cannot be completely rushed out, part of the gas passes through the grate, and the rest is entrained by the jet flow at the air inlet and is drawn into the mainstream, forming a large backflow. However, for the single-side air-inlet layer combustion chamber equipped with an equalizer plate, most of the upper part of the air chamber is equipped with partitions, and there is a recirculation zone in front of each partition, which may also form on the grate. Local high-speed areas are very unfavorable for maintaining the stability of coal seams.

Contents of the invention

The purpose of the present invention is to provide an air chamber structure that can increase the ventilation rate of the grate at the entrance without excessive velocity peaks and can achieve a relatively uniform air distribution effect. .

In order to achieve the above object, the main solution of the present invention is: for the air chamber of the single-side air-intake layer combustion furnace, it includes two lower partitions installed inside the interior of the layer combustion furnace air chamber, and the height of the first lower partition is H1=b+ (0.50~0.65)x, the distance from the air inlet of the layered furnace air chamber is S1=(0.25~0.30)L; the height of the second lower partition is H2=b+(0.8~1.0)x, the distance from the first lower partition The distance between the plates is S2=(0.30~0.35)L, where the distance between the bottom of the b-layer furnace air chamber and the lower part of the air inlet, x is the height of the air inlet, and L is the length of the layer burner air chamber;

The air chamber of the double-sided air-intake layer-burning furnace includes a central lower partition installed in the center of the inner center of the layer-burning furnace air chamber, and a symmetrical arrangement of the first lower partition and the second lower partition located on both sides of the central lower partition. Composed of side partitions, the height of the first lower partition is H1=b+(0.50~0.65)x, and the distance from the air inlet of the air chamber is S1=(0.25~0.30)L/2; the second lower partition The height of the plate is H2=b+(0.8~1.0)x, and the distance from the first lower partition is S2=(0.30~0.35)L/2, where b is the distance between the bottom of the air chamber and the lower part of the air inlet, and x is the air inlet The height, L is the length of the air chamber;

The height H3 of the central lower partition is greater than the height of the second lower partition H2.

The ratio of the area of the rectangular part to the trapezoidal part of the outer cross-section of the air chamber of the layer-burning furnace is 1:1.2~1.5.

The ratio of the cross-section of the air inlet of the layer-burning furnace air chamber to the area of the outdoor cross-section of the layer-burning furnace air chamber is 0.3-0.7:1.

The structure of the lower baffle air chamber proposed by the present invention is similar to the form of the equal pressure air chamber. Although the lower baffle makes the air flow in the lower part of the air chamber roll very complicated, the air flow in the upper part of the air chamber is distributed more evenly, so that there will be no excessive airflow. The peak speed can achieve a relatively uniform air distribution effect.

Description of drawings

Fig. 1 is a schematic view of the side structure of the air chamber of the single-side air-inlet layer combustion furnace of the present invention;

Fig. 2 is a schematic diagram of the side structure of the air chamber of the double-side air-inlet layer combustion furnace of the present invention;

Fig. 3 is a schematic view of the front structure of the air chamber of the layer-burning furnace of the present invention.

Detailed ways

The structural principle of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Embodiment 1, referring to Figures 1 and 3, for the air chamber of the single-side air-inlet layer combustion furnace, the present invention installs two lower partitions in the air chamber, and the height of the first lower partition 1 is H1=b+(0.50~0.65 )x, the distance from the air inlet of the layered furnace air chamber is S1=(0.25~0.30)L; the height of the second lower partition 2 is H2=b+(0.8~1.0)x, the distance from the first lower partition 1 The distance is S2=(0.30~0.35)L, where the distance between the bottom of the b-layer furnace air chamber and the lower part of the air inlet, x is the height of the air inlet, and L is the length of the layer burner air chamber; after such a lower partition is arranged, The air chamber becomes close to the form of the equal-pressure air chamber. Although the lower partition makes the flow of the lower airflow complicated, the airflow distribution in the upper part of the air chamber is relatively uniform.

Embodiment 2, referring to Fig. 2, for the air chamber of the double-sided air-intake layer combustion furnace, the present invention installs five lower baffles in the air chamber, that is, a central lower partition 3 is installed in the center of the inner layer of the air chamber of the layer combustion furnace, located at The central lower partition 3 is symmetrically arranged with a side partition combination composed of a first lower partition 1 and a second lower partition 2, and the height of the first lower partition 1 is H1=b+(0.50~0.65) x, the distance from the air inlet of the air chamber is S1=(0.25~0.30)L/2; the height of the second lower partition 2 is H2=b+(0.8~1.0)x, and the distance from the first lower partition 1 is S2=(0.30~0.35)L/2, where b is the distance between the bottom of the air chamber and the lower part of the air inlet, x is the height of the air inlet, and L is the length of the air chamber; the height H3 of the central lower partition 3 is greater than the second lower partition The height of the plate H2.

The air chamber of the double-side air-inlet layer is the same as the air chamber of the single-side air-inlet layer, and the air chamber has become a form close to the equal-pressure air chamber, which also solves the problem of the uniformity of the horizontal air distribution of the grate.

Claims (3)

1. the horizontal even air compartment structure of air distribution of a grate furnace; It is characterized in that: comprise for single admission grate furnace air compartment being installed in two inner lower clapboards of grate furnace air compartment; The height of first lower clapboard (1) is H1=b+ (0.50 ~ 0.65) x, and the distance of absciss layer burner air compartment air inlet is S1=(0.25 ~ 0.30) L; The height of second lower clapboard (2) is H2=b+ (0.8 ~ 1.0) x, is S2=(0.30 ~ 0.35) L from the distance of first lower clapboard (1), the distance of b grate furnace air compartment bottom and air inlet bottom wherein, and x is the height of air inlet, L is a grate furnace air compartment length;

Comprise the center lower clapboard (3) that is installed in grate furnace air compartment inside center for bilateral air supplying layer burner air compartment; And the symmetrically arranged side dividing plate combination of forming by first lower clapboard (1) and second lower clapboard (2) that is positioned at center lower clapboard (3) both sides; The height of said first lower clapboard (1) is H1=b+ (0.50 ~ 0.65) x, and the distance that leaves the air compartment air inlet is S1=(0.25 ~ 0.30) L/2; The height of second lower clapboard (2) is H2=b+ (0.8 ~ 1.0) x, is S2=(0.30 ~ 0.35) L/2 from the distance of first lower clapboard (1), the distance of b air compartment bottom and air inlet bottom wherein, and x is the height of air inlet, L is an air compartment length;

The height H 3 of described center lower clapboard (3) is greater than the height of the second lower clapboard H2.

2. the air compartment structure of the laterally even air distribution of grate furnace according to claim 1 is characterized in that: the outer cross section rectangle part (4) of described grate furnace air compartment is 1:1.2 ~ 1.5 with the ratio of trapezoidal portions (5) area.

3. the air compartment structure of the laterally even air distribution of grate furnace according to claim 1 is characterized in that: described grate furnace air compartment air inlet cross section is 0.3 ~ 0.7:1 with the ratio of the area in the outer cross section of grate furnace air compartment.

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