Heat transfer element of fusiform air preheater

Abstract

The utility model belongs to the technical field of boiler air preheaters and flue gas heaters, and discloses a fusiform air preheater heat transfer element. According to the technical scheme, the corrugated plate is used for increasing the heat exchange area, the corrugated plate is formed by pressing steel plates, the supporting plate is correspondingly stacked and assembled, and the corrugated plate is of a corrugated structure in the axial direction of the waists forming main corrugations of the corrugated plate. When high-temperature flue gas enters the corrugated flue gas channel to heat the heat transfer element or air enters the corrugated flue gas channel in the opposite direction to achieve heat exchange of the heat transfer element, due to the fact that the corrugated plates and the supporting plates form the corresponding wavy structures, turbulent flue gas can be formed in the channel when the flue gas passes through the corrugated flue gas channel, and the flue gas can be rapidly guided by the wavy flue gas channel; and the flue gas is in a laminar flow shape at the contact points of the corrugated plates and the supporting plates, so that adhesion of accumulated dust on corners formed by the corrugated plates and the supporting plates can be effectively avoided, the anti-blocking capability and the heat exchange efficiency of the heat transfer element are effectively improved, and the service life of the air preheater is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of boiler air preheaters and flue gas heaters, and relates to a heat transfer element of an air preheater used in the flue gas exhaust process of a thermal power plant. Background Art

[0002] The rotary air preheater is a large-scale equipment for flue gas heat recovery in thermal power plants. The heat transfer element is the core component of the rotary air preheater for heat exchange. The structure of the heat transfer element of the rotary air preheater is as follows: Figure 1 and Figure 2 As shown, a corrugated plate 1 and a support plate 2 are stacked and assembled to increase the heat exchange area. The corrugated plates 1 and 2 are made of 0.6-12mm thick steel plates pressed into various waveforms. Several groups of heat transfer elements are stacked together to form an element box, which is placed in the compartment of the air preheater. The high-temperature flue gas sent out from the flue enters the heat transfer element along the direction of arrow F1 to heat the heat transfer element, or the air enters the heat transfer element in the opposite direction to achieve heat exchange of the heat transfer element. The heat transfer element of this structure has the following defects during use: First, no matter how the corrugated shape of the corrugated plate constituting the heat transfer element is designed, a sharp dead corner 3 is formed at the corrugated connection between the corrugated plate 1 and the support plate 2. From the perspective of fluid mechanics, the smoke in these dead corners flows slowly or not at all, which directly affects the heat exchange efficiency. At the same time, it is easier to accumulate dirt and cause serious dust accumulation and corrosion, resulting in the collapse and damage of the heat exchange element formed by the corrugated plate and the support plate supporting each other. In order to eliminate the defects of the above-mentioned dead corner 3 causing serious dust accumulation and corrosion, the following method is currently used. Figure 3 As shown, a structure in which oblique triangular corrugations 4 with different angles are arranged on the surface of the corrugated plate 1, but when smoke passes through the surface of this composite element, the viscous friction and smoke flow resistance are very large. Utility Model Content

[0003] The utility model aims to provide a shuttle-shaped air preheater heat transfer element which can reduce the smoke flow resistance, reduce the viscous friction of smoke on the heat exchange element and overcome the ash blocking phenomenon.

[0004] The technical solution to achieve the above-mentioned purpose of the utility model is:

[0005] A shuttle-shaped air preheater heat transfer element, which is composed of a group of elements assembled by stacking and assembling corrugated plates pressed from steel plates and supporting plates corresponding to each other for increasing the heat exchange area, and is characterized by:

[0006] The structure of the corrugated plate is that the waist of the main corrugation is axially corrugated.

[0007] In the structure of the shuttle-shaped air preheater heat transfer element,

[0008] ——The corrugation structure of the main corrugation corresponding to the axial direction of the corrugation waist is a forward corrugation;

[0009] ——The corrugation structure of the main corrugation corresponding to the corrugation waist axis is a counter-corrugation;

[0010] ——The axial direction of the corrugated plate is corrugated.

[0011] The shuttle-shaped air preheater heat transfer element provided by the utility model has the following advantages compared with the prior art: firstly, since the waist of the main corrugation constituting the corrugated plate structure of the air preheater heat transfer element is a corrugated structure, a group of heat transfer elements are formed by correspondingly stacking with the support plate, and a forward wave-shaped structure or a corresponding wave-shaped structure with varying width is formed at the smoke inlet of the heat transfer element, so that turbulent smoke is formed in its channel when the smoke passes through, which can effectively avoid dust accumulation and adhesion on the edges and corners formed by the corrugated plate and the support plate, and can effectively improve its anti-blocking ability, increase the heat exchange area, and improve the heat exchange efficiency of the heat transfer element; secondly, since the corrugated plate constituting the air preheater heat transfer element is corrugated in the axial and longitudinal directions, not only its surface area is increased, but also the strength of the element is further increased, and its anti-fragmentation and anti-deformation performance and life are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the end structure of the heat transfer element of the prior art air preheater;

[0013] Figure 2 It is a structural schematic diagram of a heat transfer element of an air preheater in the prior art;

[0014] Figure 3 A schematic diagram of the structure of a second type of corrugated plate constituting a heat transfer element of an air preheater in the prior art;

[0015] Figure 4 This is a schematic diagram of the end structure of the shuttle-shaped air preheater heat transfer element provided by the utility model;

[0016] Figure 5 for Figure 4 A schematic diagram of the top surface structure of the heat transfer element shown;

[0017] Figure 6 for Figure 4 A schematic diagram of a second top surface structure of the heat transfer element shown;

[0018] Figure 7 It is a schematic diagram of the side structure of the shuttle-shaped air preheater heat transfer element. DETAILED DESCRIPTION

[0019] The structure and operating principle of a shuttle-shaped air preheater heat transfer element provided by the utility model are further described in detail below in conjunction with the accompanying drawings:

[0020] like Figure 4 , 5 As shown, the structure of a shuttle-shaped air preheater heat transfer element provided by the utility model comprises a group of heat transfer elements composed of a corrugated plate 1 (corrugated in the X-axis direction) pressed from steel plates and a support plate 2, which are stacked and assembled correspondingly to each other, for increasing the heat exchange area. The structure of the corrugated plate is that the waist 6 constituting the main corrugation 5 is a corrugated structure in the Z-axis direction (the flue gas flow direction) F.

[0021] That is, when high-temperature flue gas enters from the direction of arrow F to heat the heat transfer element, or air enters from the opposite direction to achieve heat exchange of the heat transfer element, the flue gas can not only pass through the heat transfer element, but also pass through the heat transfer element. Figure 4 Turbulent smoke is formed in the end channel shown in the figure, and the smoke will be quickly guided by the wavy smoke channel; at the contact point between the corrugated plate 1 and the support plate 2, the smoke is in a laminar flow state, which can effectively avoid the corners formed by the corrugated plate 1 and the support plate 2. product The adhesion of ash effectively improves the anti-blocking ability and heat exchange efficiency of the heat transfer element;

[0022] In the structure constituting the above shuttle-shaped air preheater heat transfer element:

[0023] The shape of the corrugated structure 6 in the Z-axis direction of the corresponding wave waist constituting the above-mentioned main corrugation can be not only as follows Figure 6 It is a forward corrugated shape, that is, the width d of adjacent corrugated structures 6 does not change; it can also be as follows Figure 5 The opposite corrugations shown, that is, the width d of the adjacent corrugated structures 6 is a variable width structure; when the smoke passes through Figure 5 When the heat transfer element with the adjacent corrugated structure 6 having a variable width exchanges heat, the flue gas in the axial direction presents a stronger turbulence, and the flue gas flow rate increases, making it less likely for the heat transfer element to accumulate dust 4.

[0024] ——When the Y-axis direction of the corrugated plate 1 is corrugated, Figure 7 As shown in the figure, the flue gas channel formed by the combination with the support plate 2 is a flue gas channel in which the main corrugation 5 is corrugated in the three directions of the X-axis, Z-axis and Y-axis. When high-speed flue gas enters it, extremely complex turbulent and laminar flow forms will be formed. The flue gas will be quickly guided by the wavy channel, thereby improving the dust accumulation resistance of the heat transfer element surface formed by the corrugated plate 1 and the support plate 2, effectively reducing the smoke flow resistance, reducing the viscosity friction of the smoke on the heat exchange element, and improving the overall heat exchange efficiency of the air preheater.

Claims

1. A shuttle-shaped air preheater heat transfer element, which is composed of a group of elements assembled by stacking and assembling corrugated plates pressed from steel plates and supporting plates corresponding to each other for increasing the heat exchange area, and is characterized by: The structure of the corrugated plate is that the waist of the main corrugation is axially corrugated.

2. The shuttle-shaped air preheater heat transfer element according to claim 1, characterized in that: The corrugation structure corresponding to the axial direction of the waist of the main corrugation is a forward corrugation.

3. The shuttle-shaped air preheater heat transfer element according to claim 1, characterized in that: The corrugated structure of the main corrugation corresponding to the axial direction of the corrugation waist is a counter-corrugated shape.

4. The shuttle-shaped air preheater heat transfer element according to claim 1, characterized in that: The corrugated plate is axially corrugated.

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