Furnace wall structure of pulverized coal furnace

Abstract

The utility model relates to the technical field of pulverized coal furnaces, in particular to a boiler wall structure of a pulverized coal furnace, and aims to solve the technical problem that the heat efficiency and the operation stability of a boiler are affected due to the fact that water cooling wall tubes in a boiler wall structure in the prior art are uniformly distributed in the boiler wall at fixed intervals. A spiral pipe is wound between the metal furnace wall and the outer wall, the bottom wall of the outer wall is connected with a combustor, the combustor is communicated with a pulverized coal pipe, the screw pitch of the spiral pipe is gradually reduced from top to bottom, the liquid inlet end of the spiral pipe is located on the lower portion of the outer wall, and the liquid outlet end of the spiral pipe is located on the upper portion of the outer wall. Stress concentration at the pipeline connecting position is reduced, the possibility of leakage and damage is reduced, the number of turns of the water-cooling pipe in a high-temperature area is large, the heating area is large, heat can be fully absorbed, little heat can be absorbed in a low-temperature area, heat corresponding to the number of turns is reduced, and the heat efficiency and operation stability of the boiler are improved through variable screw pitches.

Description

Technical Field

[0001] This utility model relates to the field of pulverized coal furnace technology, specifically to a pulverized coal furnace wall structure. Background Technology

[0002] The development of pulverized coal boiler wall structures has gradually evolved with the continuous advancement of boiler technology and the increasing demands on boiler performance. Early pulverized coal boilers primarily used heavy-duty walls. These walls were constructed from materials such as red bricks and refractory bricks, resulting in a relatively simple structure. Their advantages included high strength and good refractory performance, but they also had significant disadvantages, such as heavy weight, requiring high-quality boiler foundations; large heat loss, affecting boiler thermal efficiency; and complex construction processes and long construction periods. With the improvement of boiler parameters and capacity, tube-type walls emerged. These walls use water-cooled wall tubes as the supporting structure, with refractory and insulation materials laid on the tube banks. Their advantages include light weight, reducing the load on the boiler frame; good sealing, effectively reducing air leakage; low heat loss, improving boiler thermal efficiency; and relatively simple construction, allowing for factory prefabrication and on-site assembly, shortening the installation cycle.

[0003] In existing furnace wall structures, the fixed gaps of the water-cooled wall tubes are evenly distributed within the furnace wall. This results in insufficient heat absorption by the water-cooled wall tubes, while other areas may experience excessive heat absorption, affecting the boiler's thermal efficiency and operational stability. Utility Model Content

[0004] This invention addresses the technical problem in existing furnace wall structures where the fixed gaps of water-cooled wall tubes are evenly distributed within the furnace wall, affecting the boiler's thermal efficiency and operational stability. Therefore, this invention provides a pulverized coal boiler furnace wall structure.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a pulverized coal furnace wall structure, comprising: an outer wall, a metal furnace wall inside the outer wall, a spiral tube wound between the metal furnace wall and the outer wall, a burner connected to the bottom wall of the outer wall, the burner being connected to a pulverized coal pipe, the pitch of the spiral tube gradually decreasing from top to bottom, the liquid inlet end of the spiral tube being located at the lower part of the outer wall, and the liquid outlet end of the spiral tube being located at the upper part of the outer wall.

[0006] Preferably, multiple spiral tubes are arranged vertically.

[0007] Preferably, a heat insulation layer is provided between the outer side of the spiral tube and the inner wall of the outer wall. The heat insulation layer consists of an inner heat insulation layer, a connecting column, and an outer heat insulation layer from the inside to the outside. There is a gap between the inner heat insulation layer and the outer heat insulation layer, which are connected by the connecting column. The inner heat insulation layer is in contact with the spiral tube, and the outer heat insulation layer is in contact with the inner wall of the outer wall.

[0008] Preferably, the metal furnace wall material is austenitic stainless steel, and the heat insulation layer material is heat-insulating ceramic.

[0009] Compared with the prior art, the beneficial effects of this utility model are:

[0010] Using spiral water-cooled tubes instead of traditional vertical water-cooled tubes, the spiral shape has a certain degree of flexibility, which can alleviate the thermal stress caused by temperature changes through its own deformation, reduce stress concentration at pipe joints, and reduce the possibility of leakage and damage. Moreover, since the pitch of the spiral tube gradually decreases from top to bottom, the temperature inside the furnace gradually decreases from bottom to top. In the high-temperature region, the water-cooled tube has more turns and a larger heating area, which can fully absorb heat, while in the low-temperature region, less heat can be absorbed, and the number of turns corresponds to a decrease in heat. The change in pitch improves the boiler's thermal efficiency and operational stability.

[0011] An insulation layer is added between the water-cooled pipes and the outer wall. The insulation layer consists of two layers of insulating ceramic with poor heat conduction efficiency and an air layer in the middle to prevent internal heat loss. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] Figure 2 This is an exploded view of the structure of this utility model.

[0014] In the diagram: 1. Outer wall; 2. Metal furnace wall; 3. Spiral pipe; 4. Burner; 5. Pulverized coal pipe; 6. Inner insulation layer; 7. Connecting column; 8. Outer insulation layer. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] The rotary connection mentioned in this device refers to the axial fixation of the bearing by mounting the bearing on the shaft, with a spring retaining ring groove provided on the shaft or shaft hole, and the rotation achieved by locking the elastic retaining ring in the retaining ring groove; the hinge connection refers to the connection method that allows movement through connecting parts such as hinges, pins, and short shafts.

[0017] The present invention will now be described in detail with reference to the accompanying drawings.

[0018] The following is in conjunction with the appendix Figure 1-2This embodiment describes a pulverized coal furnace wall structure, including: an outer wall 1, a metal furnace wall 2 inside the outer wall 1, a spiral tube 3 coiled between the metal furnace wall 2 and the outer wall 1, a burner 4 connected to the bottom wall of the outer wall 1, the burner 4 being connected to a pulverized coal pipe 5, the spiral tube 3 having a gradually decreasing pitch from top to bottom, the liquid inlet end of the spiral tube 3 being located at the lower part of the outer wall 1, and the liquid outlet end of the spiral tube 3 being located at the upper part of the outer wall 1.

[0019] Water is injected from the lower end of the spiral tube 3 and discharged from the upper end. Pulverized coal enters the lower part of the pulverized coal furnace through the pulverized coal pipe 5 and is ignited by the burner 4. Some of the heat is conducted to the spiral tube 3 through the metal furnace wall 2. Under the obstruction of the metal furnace wall 2, the smoke and dust will not fall directly onto the spiral tube 3, thus extending the life of the spiral tube 3. The spiral water-cooled spiral tube 3 is used instead of the traditional vertical water-cooled tube. The spiral shape has a certain degree of extensibility, which can alleviate the thermal stress caused by temperature changes through its own deformation, reduce the stress concentration at the pipe connection, and reduce the possibility of leakage and damage. Moreover, since the pitch of the spiral tube 3 gradually decreases from top to bottom, the temperature inside the furnace gradually decreases from bottom to top. In the high-temperature area, the spiral tube 3 has more turns and a larger heating area, which can fully absorb heat. In the low-temperature area, less heat can be absorbed, and the number of turns corresponds to a decrease in heat, making the heat absorption of the water-cooled wall system more uniform. The thermal efficiency and operational stability of the pulverized coal furnace are improved by varying the pitch.

[0020] Multiple spiral tubes are arranged vertically.

[0021] Multiple spiral tubes 3 are arranged vertically. Under the premise that the arrangement density of the spiral tubes 3 remains unchanged, the pitch of a single spiral tube 3 is increased, the water flow rate is faster, and the heat conduction effect is better.

[0022] A heat insulation layer is provided between the outside of the spiral tube 3 and the inner wall of the outer wall 1. The heat insulation layer consists of an inner heat insulation layer 6, a connecting column 7, and an outer heat insulation layer 8 from the inside to the outside. There is a gap between the inner heat insulation layer 6 and the outer heat insulation layer 8, which are connected by the connecting column 7. The inner heat insulation layer 6 is in contact with the spiral tube 3, and the outer heat insulation layer 8 is in contact with the inner wall of the outer wall 1.

[0023] The inner insulation layer 6 and the outer insulation layer 8 have low thermal conductivity, which can hinder heat transfer. The air layer formed by the gap in the middle is a poor conductor of heat, which can significantly reduce the rate of heat conduction from the furnace to the external environment, reduce heat loss, improve the thermal efficiency of the pulverized coal furnace, and reduce energy consumption.

[0024] The metal furnace wall 2 is made of austenitic stainless steel, and the insulation layer is made of heat-insulating ceramic.

[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pulverized coal furnace wall structure, characterized in that: include: The outer wall (1) is equipped with a metal furnace wall (2) inside the outer wall (1). A spiral tube (3) is coiled between the metal furnace wall (2) and the outer wall (1). A burner (4) is connected to the bottom wall of the outer wall (1). The burner (4) is connected to the pulverized coal pipe (5). The pitch of the spiral tube (3) gradually decreases from top to bottom. The liquid inlet end of the spiral tube (3) is located at the lower part of the outer wall (1), and the liquid outlet end of the spiral tube (3) is located at the upper part of the outer wall (1). A heat insulation layer is provided between the outside of the spiral tube (3) and the inner wall of the outer wall (1). The heat insulation layer is provided with an inner heat insulation layer (6), a connecting column (7), and an outer heat insulation layer (8) from the inside to the outside. There is a gap between the inner heat insulation layer (6) and the outer heat insulation layer (8) and they are connected by the connecting column (7). The inner heat insulation layer (6) is in contact with the spiral tube (3), and the outer heat insulation layer (8) is in contact with the inner wall of the outer wall (1).

2. The pulverized coal furnace wall structure according to claim 1, characterized in that: The spiral tube (3) has multiple vertically arranged sections.

3. The pulverized coal furnace wall structure according to claim 1, characterized in that: The metal furnace wall (2) is made of austenitic stainless steel, and the insulation layer is made of heat-insulating ceramic.

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