Ash discharging device for increasing bed temperature of circulating fluidized bed boiler

Abstract

The utility model discloses an ash discharging device for increasing the bed temperature of a circulating fluidized bed boiler, and relates to the technical field of metallurgical equipment. The device comprises a circulating fluidized bed boiler combustion system, two accident ash discharging pipes of the circulating fluidized bed boiler combustion system are respectively connected with an ash discharging branch pipe, the two ash discharging branch pipes are respectively provided with a first metal expansion joint and an electric valve, and the two ash discharging branch pipes are connected with an ash discharging header pipe after being intersected. And the ash discharging header pipe is connected with a slag falling pipe of a circulating fluidized bed boiler combustion system. Under the condition that operation parameters of the boiler are not changed, the ash discharging header pipe is additionally arranged, the circulating ash amount is adjusted, the combustion efficiency of the boiler is improved, the proportion of fuel which is not completely combusted is reduced, the combustion efficiency and the heat efficiency can be improved, emission of harmful gas is reduced, the combustion process can be stabilized, and the service life of the boiler is prolonged. And the operation stability and safety of the boiler are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of metallurgical equipment, in particular to an ash discharging device for improving the bed temperature of a circulating fluidized bed boiler. Background Art

[0002] As an efficient and environmentally friendly coal combustion device, the circulating fluidized bed boiler has a high ash content and a large amount of circulating ash in the furnace after co-firing solid waste, resulting in incomplete combustion of the fuel in the furnace, affecting the thermal efficiency of the circulating fluidized bed boiler, causing the bed temperature of the circulating fluidized bed boiler to fail to reach the design value, being difficult to carry load, and affecting the operation economy and safety. Summary of the Utility Model

[0003] Aiming at the above technical problems, the utility model provides an ash discharging device for solving the problem that the large amount of circulating ash after co-firing solid waste in the existing circulating fluidized bed boiler affects the bed temperature of the circulating fluidized bed boiler.

[0004] In order to achieve the above purpose, the technical solution of the utility model is specifically as follows:

[0005] An ash discharging device for improving the bed temperature of a circulating fluidized bed boiler, including a circulating fluidized bed boiler combustion system. One ash discharging branch pipe is respectively connected to two accident ash discharging pipes of the circulating fluidized bed boiler combustion system. A first metal expansion joint and an electric valve are respectively arranged on the two ash discharging branch pipes. After the two ash discharging branch pipes converge, they are connected to an ash discharging main pipe, and the ash discharging main pipe is connected to the slag dropping pipe of the circulating fluidized bed boiler combustion system.

[0006] A second metal expansion joint is arranged on the ash discharging main pipe.

[0007] An insertion type expansion joint is arranged at the outlet end of the ash discharging main pipe.

[0008] A blowing pipe is arranged inside the inlet end of the ash discharging main pipe, and the blowing pipe is connected to an air source.

[0009] A main valve is arranged on the ash discharging main pipe.

[0010] It further includes a hanger, and the ash discharging main pipe is installed on the hanger.

[0011] The circulating fluidized bed boiler combustion system consists of a circulating fluidized bed boiler and a cyclone separator. There are two cyclone separators, which are installed on the upper side wall of the circulating fluidized bed boiler. Return legs are respectively arranged at the bottoms of the two cyclone separators. Accident ash discharging pipes are installed on the return legs, and accident ash discharging valves are installed on the accident ash discharging pipes. The outlet ends of the return legs are connected to the furnace bottom of the circulating fluidized bed boiler. The outlet end of the circulating fluidized bed boiler is connected to a slag cooler through a slag dropping pipe.

[0012] Compared with the prior art, the beneficial effects of the utility model are as follows: Without changing the operation parameters of the boiler, by adding a main ash discharge pipe, adjusting the circulating ash volume not only improves the combustion efficiency of the boiler, but also reduces the proportion of unburned fuel. It can not only improve the combustion efficiency and thermal efficiency, reduce harmful gas emissions, but also stabilize the combustion process, extend the service life of the boiler, and improve the stability and safety of boiler operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the utility model;

[0014] In the figure:

[0015] 1. Combustion system of circulating fluidized bed boiler; 101. Circulating fluidized bed boiler; 102. Cyclone separator; 103. Return feeder; 104. Emergency ash discharge pipe; 105. Emergency ash discharge valve; 106. Slag dropping pipe; 107. Cooler; 2. Ash discharge branch pipe; 3. First metal expansion joint; 4. Electric valve; 5. Main ash discharge pipe; 6. Second metal expansion joint; 7. Inserted expansion joint; 8. Air blowing pipe; 9. Main valve; 10. Hanger. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] To make the objectives, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the utility model. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the utility model.

[0017] An ash discharge device for increasing the bed temperature of a circulating fluidized bed boiler includes a combustion system 1 of a circulating fluidized bed boiler. One ash discharge branch pipe 2 is respectively connected to two emergency ash discharge pipes 104 of the combustion system 1 of the circulating fluidized bed boiler. A first metal expansion joint 3 and an electric valve 4 are respectively provided on the two ash discharge branch pipes 2. After the two ash discharge branch pipes 2 converge, they are connected to a main ash discharge pipe 5. The main ash discharge pipe 5 is connected to the slag dropping pipe 106 of the combustion system 1 of the circulating fluidized bed boiler. Without changing the operation parameters of the boiler, by adding the main ash discharge pipe 5, adjusting the circulating ash volume not only improves the combustion efficiency of the boiler, but also reduces the proportion of unburned fuel. It can not only improve the combustion efficiency and thermal efficiency, reduce harmful gas emissions, but also stabilize the combustion process, extend the service life of the boiler, and improve the stability and safety of boiler operation.

[0018] A second metal expansion joint 6 is provided on the main ash discharge pipe 5. By using metal expansion joints, on the one hand, it compensates for the additional stress caused by temperature difference and mechanical vibration during the ash discharge process; on the other hand, it utilizes the effective telescopic deformation of the bellows to compensate for and absorb the axial, transverse and angular thermal deformation of the ash discharge pipe.

[0019] An insertion type expansion joint 7 is provided at the outlet end of the ash discharge main pipe 5. By adopting the insertion type expansion joint 7, first, the compensation capacity is improved; second, the installation and disassembly of the pipeline are convenient; third, it is resistant to high temperature and has a long service life.

[0020] A blowing pipe 8 is arranged inside the inlet end of the ash discharge main pipe 5. The blowing pipe 8 is connected to a wind source, and a path of auxiliary blowing air is introduced from the main pipe of the fluidized bed fan into the ash discharge main pipe 5. The gas pushes the cold ash in the ash discharge pipe into the cold slag machine 107 for continuous slag discharge, preventing ash blockage in the ash discharge pipeline.

[0021] A main valve 9 is provided on the ash discharge main pipe 5, which can control the total ash discharge amount in real time according to the actual situation on site by opening and closing the valve.

[0022] It further includes a hanger 10, and the ash discharge main pipe 5 is installed on the hanger 10 to improve the stability of the operation of the ash discharge main pipe 5.

[0023] The combustion system 1 of the circulating fluidized bed boiler consists of a circulating fluidized bed boiler 101 and a cyclone separator 102. There are two cyclone separators 102, and the two cyclone separators 102 are installed on the upper side wall of the circulating fluidized bed boiler 101. Dense-phase return devices 103 are respectively provided at the bottoms of the two cyclone separators 102. An emergency ash discharge pipe 104 is provided at the bottom of the dense-phase return device 103, and an emergency ash discharge valve 105 is installed on the emergency ash discharge pipe 104. The outlet end of the dense-phase return device 103 is connected to the furnace bottom of the circulating fluidized bed boiler 101, and the outlet end of the circulating fluidized bed boiler 101 is connected to a cold slag machine 107 through a slag dropping pipe 106.

[0024] Embodiment

[0025] Most of the fine ash entering the cyclone separator 102 is collected by the cyclone separator 102 and sent back to the furnace chamber of the circulating fluidized bed boiler 101 for circulating combustion through the dense-phase return device 103 and the material circulation system. A small part of the fine particles enters the tail flue to become fly ash. The flue gas carries the material and enters the high-temperature cyclone separator 102 through the suspension section. When the flue gas passes through the high-temperature cyclone separator 102, the material carried by it is separated and returned to the furnace chamber by the dense-phase return device 103 for circulating re-combustion, resulting in a large amount of circulating ash in the furnace chamber, making the fuel in the furnace chamber unable to be completely burned out, affecting the thermal efficiency of the circulating fluidized bed boiler 101. The emergency ash discharge valve 105 connected to the dense-phase return device 103 through the ash discharge branch pipe 2 controls the ash discharge amount of the dense-phase return device 103. The two ash discharge branch pipes 2 converge into the ash discharge main pipe 5, and the ash discharge main pipe 5 then discharges the circulating ash into the cold slag machine 107. Without changing the operating parameters of the boiler, by adding the ash discharge main pipe 5 and adjusting the circulating ash amount, not only the combustion efficiency of the boiler is improved, but also the proportion of unburned fuel is reduced. It can not only improve the combustion efficiency and thermal efficiency, reduce harmful gas emissions, but also stabilize the combustion process, extend the boiler life, and improve the stability and safety of the boiler operation.

[0026] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A ash discharge device for increasing the bed temperature of a circulating fluidized bed boiler, comprising a circulating fluidized bed boiler combustion system (1), characterized in that: Two emergency ash discharge pipes (104) of a circulating fluidized bed boiler combustion system (1) are respectively connected to an ash discharge branch pipe (2), and the two ash discharge branch pipes (2) are respectively provided with a first metal expansion joint (3) and an electric valve (4). The two ash discharge branch pipes (2) are connected to an ash discharge main pipe (5) after the two ash discharge branch pipes (2) intersect, and the ash discharge main pipe (5) is connected to a slag discharge pipe (106) of the circulating fluidized bed boiler combustion system (1). The invention also includes a hanger (10), and the ash discharge main pipe (5) is installed on the hanger (10).

2. The ash placing device for increasing the bed temperature of a circulating fluidized bed boiler according to claim 1, characterized in that: The ash discharge main pipe (5) is provided with a second metal expansion joint (6).

3. The ash placing device for increasing the bed temperature of a circulating fluidized bed boiler according to claim 2, characterized in that: An insert-type expansion joint (7) is provided at the outlet end of the ash discharge main pipe (5).

4. The ash placing device for increasing the bed temperature of a circulating fluidized bed boiler according to claim 3 is characterized in that: An air blowing pipe (8) is provided at the inlet end of the ash discharge main pipe (5), and the air blowing pipe (8) is connected to an air source.

5. The ash discharge device for increasing the bed temperature of a circulating fluidized bed boiler according to claim 4, characterized in that: The ash discharge main pipe (5) is provided with a main valve (9).

6. The ash discharge device for increasing the bed temperature of a circulating fluidized bed boiler according to claim 5, characterized in that: The circulating fluidized bed boiler combustion system (1) comprises a circulating fluidized bed boiler (101) and a cyclone separator (102). Two cyclone separators (102) are provided. The two cyclone separators (102) are installed on the upper side wall of the circulating fluidized bed boiler (101). Returners (103) are provided at the bottom of the two cyclone separators (102). An emergency ash discharge pipe (104) is provided at the bottom of the returner (103). An emergency ash discharge valve (105) is installed on the emergency ash discharge pipe (104). The outlet end of the returner (103) is connected to the furnace bottom of the circulating fluidized bed boiler (101). The outlet end of the circulating fluidized bed boiler (101) is connected to a slag cooler (107) via a slag drop pipe (106).

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