Coal powder boiler with burning grate and its ash hopper structure and arrangement method
By adding a vertical water-cooled wall and a combustion chamber structure to the cold ash hopper of the power plant boiler, the problem of some coal types not being able to be completely burned was solved, effective grate support and secondary combustion of unburned pulverized coal were achieved, boiler efficiency was improved and the problem of inconsistent expansion was solved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN BOILER CO LTD
- Filing Date
- 2022-08-04
- Publication Date
- 2026-06-02
AI Technical Summary
In existing power plant boilers, some types of coal cannot be completely burned at the cold ash hopper, resulting in a complex design of the water-cooled wall of the cold ash hopper. Furthermore, unburned coal powder falls directly into the slag pit, reducing the heat entering the furnace and affecting boiler efficiency.
A vertical water-cooled wall is added below the water-cooled wall after the cold ash hopper is closed to form a combustion chamber. A grate is installed and a frame structure is designed to support the grate. A central tube screen is set in the combustion chamber to prevent unburned coal powder from falling into the slag pit. T-shaped welded parts are used to connect the grate and the ash hopper to solve the problem of inconsistent expansion.
It effectively improves boiler efficiency, prevents unburned pulverized coal from falling directly into the slag pit, ensures synchronous expansion of the grate and ash hopper, avoids heat loss, improves combustion efficiency, and saves costs.
Smart Images
Figure CN115289493B_ABST
Abstract
Description
Technical fields:
[0002] This invention relates to the field of power plant boiler technology, specifically to a cold ash hopper structure and arrangement method for a pulverized coal boiler with a burnout grate. Background technology:
[0004] Most existing power plant boilers are pulverized coal boilers. After the pulverized coal is burned out, it falls directly into the cold ash hopper and slag pit. However, some types of coal cannot be burned out and require a burnout grate to be installed at the cold ash hopper. The water-cooled wall of the cold ash hopper requires a special design structure to cooperate with the grate. At present, there is an urgent need for a structural arrangement that can enable the pulverized coal to burn out in order to improve the efficiency of the boiler. Summary of the Invention:
[0006] The purpose of this invention is to provide a structure and arrangement method for a cold ash hopper in a pulverized coal boiler with a burnout grate. This structure and method involves adding a vertical water-cooled wall, namely the burnout chamber water-cooled wall, below the water-cooled wall after the cold ash hopper is closed, to form a space for installing the grate. The lower header of the water-cooled wall is designed in the form of a frame to support the grate and hang the ash hopper below. A central tube screen of the burnout chamber is designed above the slag pit to prevent unburned pulverized coal from falling directly into the slag pit, which would reduce the heat entering the furnace and effectively improve boiler efficiency.
[0007] The above objectives are achieved through the following technical solutions:
[0008] A cold ash hopper structure for a pulverized coal boiler with a burnout grate comprises: a burnout chamber water-cooled wall, wherein the burnout chamber water-cooled wall is formed by adding a section of vertical water-cooled wall below the spiral water-cooled wall after the cold ash hopper is closed, creating a space for installing the grate; a grate beam is installed below the grate; the grate is connected to the lower header of the water-cooled wall via a support beam; the lower header of the water-cooled wall is a frame structure, and its bottom is connected to the ash hopper via a T-shaped pre-welded component; the grate is symmetrically arranged on both sides of the furnace centerline, with a slag well installed in the middle; a burnout chamber central tube screen is installed above the slag well; two burnout chamber central tube screen inlet headers are installed at the bottom of the burnout chamber central tube screen, and a burnout chamber central tube screen outlet header is installed at the top.
[0009] A structure and arrangement method for a cold ash hopper in a pulverized coal boiler with a burnout grate, the method comprising the following steps:
[0010] Firstly, a vertical water-cooled wall, namely the combustion chamber water-cooled wall, is added below the spiral water-cooled wall after the cold ash hopper is closed, forming a space for installing the grate. The grate is symmetrically arranged on both sides of the furnace centerline. The lower header of the water-cooled wall is designed as a frame to support the grate and hang the ash hopper below. Each lower header of the water-cooled wall in the furnace depth direction has a support beam above it, which is connected to the grate beam above it to provide support. The load of the grate is applied to the lower header of the water-cooled wall. The reciprocating motion of the grate is driven by a push-pull rod passing through the water-cooled wall and a motor. A side sealing pipe is provided between the grate and the water-cooled wall.
[0011] A T-shaped pre-welded part is welded below the lower header of each water-cooled wall in the furnace depth direction. The ash hopper below the grate is welded onto the pre-welded part. The grate, the ash hopper and the water-cooled wall expand together.
[0012] A central tube screen for the combustion chamber is arranged above the slag pit. Two inlet headers are installed at the bottom of the screen, and an outlet header is installed at the top on the center line of the furnace. The central tube screen for the combustion chamber is used to prevent unburned coal powder from falling directly into the slag pit. All unburned fuel falls onto the grate for secondary combustion, which avoids a reduction in the heat entering the furnace and improves boiler efficiency.
[0013] Beneficial effects:
[0014] 1. This invention relates to a cold ash hopper structure and its arrangement method for a pulverized coal boiler with a burnout grate. Specifically, a vertical water-cooled wall, namely the burnout chamber water-cooled wall, is added below the water-cooled wall after the cold ash hopper is closed. This creates space for installing the grate, which also supports the grate and suspends the ash hopper below. The central tube screen of the burnout chamber prevents unburned pulverized coal from falling directly into the slag pit, thus reducing the heat entering the boiler and effectively improving the boiler's efficiency.
[0015] 2. In this invention, a T-shaped pre-welded part is welded below the lower header of each water-cooled wall in the furnace depth direction, and the ash hopper below the grate is welded to the pre-welded part. This arrangement allows the grate, ash hopper and water-cooled wall to expand together, thus solving both the load-bearing problem of the grate and ash hopper and the problem of inconsistent expansion when hung separately.
[0016] 3. The present invention arranges and designs a central tube screen structure for the combustion chamber above the slag pit to prevent unburned coal powder from falling directly into the slag pit. All unburned fuel falls onto the grate for secondary combustion, avoiding a reduction in the heat entering the furnace and effectively improving boiler efficiency. Attached image description:
[0018] Appendix Figure 1 This is a schematic diagram of the structure of the present invention.
[0019] Appendix Figure 2 It is attached Figure 1 Top view.
[0020] Appendix Figure 3 It is attached Figure 1 The left view in the image.
[0021] Among them: 1. Water-cooled wall of combustion chamber, 2. Grate, 3. Central tube screen of combustion chamber, 4. Outlet header of central tube screen of combustion chamber, 5. Inlet header of central tube screen of combustion chamber, 6. Lower header of water-cooled wall, 7. Slag well, 8. T-shaped pre-welded parts, 9. Ash hopper, 10. Support beam, 11. Grate beam. Detailed implementation method:
[0023] Example 1:
[0024] A cold ash hopper structure for a pulverized coal boiler with a burnout grate comprises: a burnout chamber water-cooled wall 1, wherein the burnout chamber water-cooled wall is formed by adding a section of vertical water-cooled wall below the spiral water-cooled wall after the cold ash hopper is closed, forming a space for installing the grate 2; a grate beam 11 is installed below the grate; the grate is connected to the lower header 6 of the water-cooled wall via a support beam 10; the lower header of the water-cooled wall is a frame structure, and its bottom is connected to the ash hopper 9 via a T-shaped pre-welded part 8; the grate is symmetrically arranged on both sides of the furnace centerline, with a slag well 7 installed in the middle; a burnout chamber central tube screen 3 is installed above the slag well; two burnout chamber central tube screen inlet headers 5 are installed at the bottom of the burnout chamber central tube screen; and a burnout chamber central tube screen outlet header 4 is installed at the top.
[0025] The structure of the central tube screen in the combustion chamber is set as a triangle, with the two outlet headers at the bottom being larger than the slag well opening. This allows unburned fuel to fall onto the grate for secondary combustion, preventing a reduction in the heat entering the furnace, improving boiler efficiency, and saving costs.
[0026] Example 2:
[0027] According to the structure and arrangement method of the cold ash hopper of the pulverized coal boiler with a burnout grate described in Examples 1-3, the method includes the following steps:
[0028] Firstly, a vertical water-cooled wall, namely the combustion chamber water-cooled wall, is added below the spiral water-cooled wall after the cold ash hopper is closed, forming a space for installing the grate. The grate is symmetrically arranged on both sides of the furnace centerline. The lower header of the water-cooled wall is designed as a frame to support the grate and hang the ash hopper below. Each lower header of the water-cooled wall in the furnace width direction has a support beam above it, which is connected to the grate beam above it for support. The load of the grate is applied to the lower header of the water-cooled wall. The reciprocating motion of the grate is driven by a push-pull rod and a motor passing through the water-cooled wall. A side sealing pipe is provided between the grate and the water-cooled wall.
[0029] A T-shaped pre-welded part is welded below the lower header of each water-cooled wall in the furnace depth direction. The ash hopper below the grate is welded onto the pre-welded part. The grate, the ash hopper and the water-cooled wall expand together.
[0030] A central tube screen for the combustion chamber is arranged above the slag pit. Two inlet headers are installed at the bottom of the screen, and an outlet header is installed at the top on the symmetrical center line of the boiler. The central tube screen for the combustion chamber is used to prevent unburned coal powder from falling directly into the slag pit. All unburned fuel falls onto the grate for secondary combustion, avoiding a reduction in the heat entering the furnace and improving boiler efficiency.
[0031] To address the aforementioned issue of installing burnout grates in the cold ash hopper of pulverized coal boilers, this application proposes a water-cooled wall structure for the cold ash hopper that provides space for grate installation and supports the grate, thereby completely resolving the problem of existing pulverized coal boilers requiring the installation of burnout grates for certain coal types that cannot be completely burned.
Claims
1. A method for arranging the cold ash hopper structure of a pulverized coal boiler with a burnout grate, characterized in that: The method includes the following steps: First, a vertical water-cooled wall, namely the combustion chamber water-cooled wall, is added below the spiral water-cooled wall after the cold ash hopper is closed, forming a space for installing the grate. The grate is symmetrically arranged on both sides of the furnace centerline. The lower header of the water-cooled wall is designed as a frame to support the grate and hang the ash hopper below. Each lower header of the water-cooled wall in the furnace depth direction has a support beam above it, which is connected to the grate beam above it for support. The load of the grate is applied to the lower header of the water-cooled wall. The reciprocating motion of the grate is driven by a push-pull rod passing through the water-cooled wall and a motor. A side sealing pipe is provided between the grate and the water-cooled wall. A T-shaped pre-welded part is welded below each lower header of the water-cooled wall in the furnace depth direction. The ash hopper below the grate is welded to the pre-welded part. The grate, the ash hopper, and the water-cooled wall expand together. A central tube screen for the combustion chamber is arranged above the slag pit. Two inlet headers are installed at the bottom of the screen, and an outlet header is installed at the top on the center line of the furnace. The central tube screen for the combustion chamber is used to prevent unburned coal powder from falling directly into the slag pit. All unburned fuel falls onto the grate for secondary combustion, which avoids a reduction in the heat entering the furnace and improves boiler efficiency. A cold ash hopper structure for a pulverized coal boiler with a burnout grate includes: a water-cooled wall for the burnout chamber, wherein the water-cooled wall for the burnout chamber is formed by adding a section of vertical water-cooled wall below the spiral water-cooled wall after the cold ash hopper is closed, creating a space for installing the grate; a grate beam is installed below the grate; the grate is connected to the lower header of the water-cooled wall via a support beam; the lower header of the water-cooled wall is a frame structure, and its bottom is connected to the ash hopper via a T-shaped pre-welded component; the grate is symmetrically arranged on both sides of the furnace centerline, with a slag well installed in the middle; a central tube screen for the burnout chamber is installed above the slag well; two inlet headers for the central tube screen for the burnout chamber are installed at the bottom of the central tube screen for the burnout chamber, and an outlet header for the central tube screen for the burnout chamber is installed at the top of the central tube screen for the burnout chamber.