Fire extinguishing system of coal mill
Patent Information
- Application Number
- CN202421253738.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-03
- Publication Date
- 2025-02-21
- Estimated Expiration
- 2034-06-03
AI Technical Summary
Coal mills are prone to spontaneous combustion or explosion under abnormal working conditions such as starting, shutting down and coal cutting, resulting in safety hazards, and it is difficult to intervene in time and effectively in an existing fire extinguishing system.
A coal mill fire extinguishing system is designed, using carbon dioxide as explosion-proof and fire-extinguishing medium, detect fire through a fire detector and control the opening of the gas gate valve, and quickly inject carbon dioxide to extinguish the fire.
Timely intervention in the spontaneous combustion or detonation of coal mills has been achieved, avoiding the increase in grinding or accidents, improving safety and equipment reliability, and reducing operating costs.
Smart Images
Figure CN222514025U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of coal mills, and in particular, to a coal mill fire extinguishing system. Background Art
[0002] Coal mill is an important component of thermal power plant, and the safe operation of coal mill is of vital importance to thermal power plant. When burning lignite with high volatility, flammable and explosive, spontaneous combustion and even explosion are very likely to occur under abnormal conditions such as coal mill startup, shutdown and coal shortage, which brings safety hazards to coal mill equipment and personnel. Therefore, it is necessary to set up fire extinguishing steam to intervene and deal with the spontaneous combustion of coal powder in the coal mill. At present, coal mills in thermal power plants are generally equipped with steam as a means of fire extinguishing. The traditional coal mill fire extinguishing steam is taken from the auxiliary steam header and sprayed from the bottom of the coal mill. The electric door is used to control the input and shutdown of the fire extinguishing steam to extinguish the burning coal powder and prevent the accident from further expanding.
[0003] In the related technology, the coal mill fire extinguishing protection system mainly uses steam as the inerting medium, which is generally manually controlled by the operator and put into operation by the operator before starting and stopping the coal mill or after a spontaneous combustion or deflagration accident occurs. It is difficult to intervene in time and effectively with the fire extinguishing steam during operation. Usually, the spontaneous combustion or deflagration of the coal mill is judged by the coal mill outlet temperature and the roller bearing temperature. Since the coal mill outlet temperature often has a long response time, when the high roller bearing temperature alarm is sounded or the operator finds that the coal mill outlet temperature is abnormal, the spontaneous combustion or deflagration of the coal mill may have spread rapidly, making it difficult to intervene in time and effectively, resulting in mill jumping or equipment damage. After the coal mill is sprayed with water, the coal accumulated in the coal mill needs to be emptied to prevent the coal powder from being bonded with water and causing spontaneous combustion, and the stone coal from being watered. Utility Model Content
[0004] An object of the present disclosure is to provide a coal mill fire extinguishing system to at least partially solve the problems existing in the related art.
[0005] In order to achieve the above-mentioned objectives, the present disclosure provides a coal mill fire extinguishing system, comprising a coal mill, wherein the coal mill has a coal mill powder inlet pipe and a coal mill powder outlet pipe for connecting to a boiler, a fire detector is provided in the coal mill, the coal mill fire extinguishing system further comprises a carbon dioxide inlet pipe connected to the coal mill, a gas gate valve is provided in the carbon dioxide inlet pipe, and the coal mill fire extinguishing system further comprises a controller electrically connected to the fire detector and the gas gate valve.
[0006] Optionally, the coal mill fire extinguishing system further includes a hot air duct, which is connected to the coal mill.
[0007] Optionally, the coal mill fire extinguishing system further includes a cold air duct, which is connected to the coal mill.
[0008] Optionally, the carbon dioxide inlet pipe is connected to the hot air duct.
[0009] Optionally, a differential pressure flow meter is installed on the hot air duct, and the differential pressure flow meter is placed upstream of the connection between the carbon dioxide inlet pipe and the hot air duct.
[0010] Optionally, an oxygen content monitor is installed on the hot air duct, and the oxygen content monitor is placed at a position of the hot air duct close to the coal mill.
[0011] Optionally, the carbon dioxide inlet pipe is arranged to be inclined downward.
[0012] Optionally, a pebble coal discharge valve is connected to the bottom of the coal mill.
[0013] Optionally, the coal mill is also connected to a steam fire extinguishing pipeline, and a temperature and pressure reducing valve is provided on the steam fire extinguishing pipeline.
[0014] Optionally, a steam trap is provided on the steam fire extinguishing pipeline upstream of the temperature reduction and pressure reducing valve.
[0015] Through the above technical scheme, the fire detector detects the fire and sends a signal, which serves as the opening condition of the carbon dioxide gas gate valve, and quickly intervenes in the spontaneous combustion or deflagration of the coal mill, avoiding the coal mill jumping or effectively preventing the expansion of the accident. Carbon dioxide is used as the explosion-proof and fire-extinguishing medium of the coal mill. It has high purity and greater density than air, and has better explosion-proof and fire-extinguishing effects. It can more effectively prevent coal mill explosion accidents in coal-fired power plants and timely eliminate coal powder spontaneous combustion, fire and other accidents in the coal mill. In addition, the carbon dioxide gas fire extinguishing response time is short and the intervention is timely, which avoids the expansion of accidents due to improper human operation of fire extinguishing steam, and realizes the real-time and timeliness required for coal mill explosion prevention and fire extinguishing. Injecting a large amount of carbon dioxide can quickly reduce the oxygen content in the coal mill, leaving no water stains, avoiding the filling of fire extinguishing steam into the coal mill, and preventing excessive steam from causing water accumulation in the coal mill. The coal mill fire extinguishing system is flexible in setting, low in operating cost, improves the operating reliability of power plant equipment, is easy to manage, saves time and effort, and is more practical.
[0016] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:
[0018] Figure 1 It is a structural schematic diagram of a coal mill fire extinguishing system provided in an exemplary embodiment of the present disclosure.
[0019] Description of Reference Numerals
[0020] 1 Coal mill 11 Coal mill powder inlet pipe
[0021] 12 Coal mill powder outlet pipe 2 Fire detector
[0022] 3 Carbon dioxide intake pipe 31 Gas gate valve
[0023] 4 controller 5 hot air duct
[0024] 51 Differential pressure flow meter 52 Oxygen monitor
[0025] 6 Cold air duct 7 Stone coal discharge valve
[0026] 8 Steam fire extinguishing pipeline 81 temperature reduction and pressure relief valve
[0027] 9. Steam Trap DETAILED DESCRIPTION
[0028] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.
[0029] In the present disclosure, unless otherwise specified, the directional terms "upper", "lower", "top", and "bottom" used are defined based on the directions in which the relevant components are actually used. "Inside" and "outside" refer to the contours of the corresponding components themselves. In the present disclosure, when the following description refers to the drawings, unless otherwise specified, the same numbers in different drawings represent the same or similar elements.
[0030] Reference Figure 1 The present disclosure provides a coal mill fire extinguishing system, which may include a coal mill 1, the coal mill 1 having a coal mill powder inlet pipe 11 and a coal mill powder outlet pipe 12 for connecting to a boiler, a fire detector 2 is provided in the coal mill 1, the coal mill fire extinguishing system may also include a carbon dioxide inlet pipe 3 connected to the coal mill 1, a gas gate valve 31 is provided in the carbon dioxide inlet pipe 3, and the coal mill fire extinguishing system may also include a controller 4 electrically connected to the fire detector 2 and the gas gate valve 31. Specifically, when a fire occurs in the coal mill 1 or there are signs of fire, the fire detector 2 transmits the detected signal to the distributed control system, and the distributed control system controls the alarm in the control room to sound an alarm, and controls the controller 4 to send a signal to control the gas gate valve 31 to open and spray carbon dioxide gas. In an embodiment of the present disclosure, the carbon dioxide inlet pipe 3 is connected to the carbon capture system, so that the source of carbon dioxide is stable and the inventory is guaranteed, which can meet the working conditions of extinguishing multiple coal mills at the same time.
[0031] Through the above technical solution, the coal mill feeds coal powder into the mill through the mill powder inlet pipe for grinding, and feeds the coal powder into the boiler for combustion through the mill powder outlet pipe. When a fire breaks out in the mill, the fire detector in the mill detects the fire, alarms and transmits the fire signal to the controller, which sends a signal to the gas gate valve to control the gas gate valve to open, and the carbon dioxide gas is put into operation and enters the mill to extinguish the fire. The fire detector detects the fire and sends a signal as the opening condition of the carbon dioxide gas gate valve, which quickly intervenes in the spontaneous combustion or deflagration of the mill to avoid the mill jumping or effectively prevent the accident from expanding.
[0032] Carbon dioxide is used as the explosion-proof and fire-extinguishing medium for coal mills. It has high purity and greater density than air, and has better explosion-proof and fire-extinguishing effects. It can more effectively prevent coal-fired power plant coal mill explosion accidents and promptly eliminate coal powder spontaneous combustion and fire accidents in coal mills. In addition, the carbon dioxide gas fire extinguishing response time is short and the intervention is timely, which avoids the expansion of accidents due to improper human operation of fire extinguishing steam, and realizes the real-time and timeliness required for coal mill explosion prevention and fire extinguishing. Injecting a large amount of carbon dioxide can quickly reduce the oxygen content in the coal mill, leaving no water stains, avoid filling the coal mill with fire extinguishing steam, and prevent excessive steam from causing water accumulation in the coal mill. The coal mill fire extinguishing system is flexible in setting, low in operating cost, improves the operating reliability of power plant equipment, is easy to manage, saves time and effort, and is more practical.
[0033] As an exemplary embodiment of the present disclosure, refer to Figure 1 The coal mill fire extinguishing system may further include a hot air duct 5, which is connected to the coal mill 1. The hot air duct 5 blows hot air into the coal mill 1 to quickly send the combustibles in the coal mill into the furnace, so that the coal mill can be safely restarted after being emptied.
[0034] As an exemplary embodiment of the present disclosure, refer to Figure 1 The coal mill fire extinguishing system may further include a cold air duct 6, which is connected to the coal mill 1. The cold air duct 6 blows cold air into the coal mill 1 to neutralize the hot air and make the airflow reach a suitable temperature.
[0035] Further, refer to Figure 1 , the carbon dioxide inlet pipe 3 can be connected to the hot air pipe 5. The hot air input through the hot air pipe 5 can quickly pass the carbon dioxide in the carbon dioxide inlet pipe 3 into the coal mill 1, meeting the actual need for rapid commissioning of carbon dioxide to control deflagration, and the mixture of carbon dioxide and hot air can play a role in drying carbon dioxide without leaving water stains, thereby avoiding water accumulation in the coal mill 1.
[0036] In some embodiments, reference Figure 1A differential pressure flow meter 51 may be installed on the hot air duct 5, and the differential pressure flow meter 51 is placed upstream of the connection between the carbon dioxide inlet pipe 3 and the hot air duct 5. The differential pressure flow meter 51 is used to detect the air flow input into the hot air duct 5, so as to control the carbon dioxide flow sent into the coal mill 1.
[0037] In some embodiments, reference Figure 1 The hot air duct 5 may be equipped with an oxygen monitor 52, which is placed at a position of the hot air duct 5 close to the coal mill 1. The oxygen monitor 52 has an oxygen detection end, which extends into the hot air duct 5 and is used to detect the oxygen content inside the hot air duct 5, mainly detecting the oxygen content in the hot air and carbon dioxide mixed gas input into the coal mill 1, so as to accurately estimate the fire extinguishing properties of the mixed gas.
[0038] Among them, reference Figure 1 The carbon dioxide inlet pipe 3 can be arranged to tilt downward. Carbon dioxide has a higher density than air, and the carbon dioxide inlet pipe 3 tilted downward is conducive to faster filling of the fire extinguishing gas into the coal mill 1.
[0039] In some embodiments, reference Figure 1 The bottom of the coal mill 1 may be connected with a stone coal discharge valve 7. After the fire is extinguished, the stone coal discharge valve 7 is opened to discharge the residual ash produced after the combustion.
[0040] According to an exemplary embodiment of the present disclosure, Figure 1 The coal mill 1 can also be connected to a steam fire extinguishing pipeline 8, on which a temperature reducing and pressure reducing valve 81 is provided. When the coal mill catches fire, the steam fire extinguishing pipeline 8 can be manually put into operation as a backup protection of the carbon dioxide gas fire extinguishing system. Since the steam source parameters of the steam system do not match the fire steam parameters of the coal mill, the temperature reducing and pressure reducing valve 81 needs to be opened when the explosion-proof steam is put into operation.
[0041] Further, refer to Figure 1 A steam trap 9 may be provided on the steam extinguishing pipeline 8 upstream of the temperature reducing and pressure reducing valve 81. Before the steam enters the coal mill 1, it needs to be drained through the steam trap 9, and the condensed water is directly discharged into the ditch through the steam trap 9.
[0042] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.
[0043] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.
[0044] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.
Claims
1. A coal mill fire extinguishing system, characterized in that: The invention comprises a coal mill, wherein the coal mill has a coal mill powder inlet pipe and a coal mill powder outlet pipe connected to a boiler, a fire detector is arranged in the coal mill, the coal mill fire extinguishing system further comprises a carbon dioxide inlet pipe connected to the coal mill, a gas gate valve is arranged in the carbon dioxide inlet pipe, and the coal mill fire extinguishing system further comprises a controller electrically connected to the fire detector and the gas gate valve.
2. The coal mill fire extinguishing system according to claim 1, characterized in that: The coal mill fire extinguishing system further comprises a hot air duct, and the hot air duct is communicated with the coal mill.
3. The coal mill fire extinguishing system according to claim 2, characterized in that: The coal mill fire extinguishing system also includes a cold air duct, which is connected to the coal mill.
4. The coal mill fire extinguishing system according to claim 2, characterized in that: The carbon dioxide intake pipe is connected to the hot air duct.
5. The coal mill fire extinguishing system according to claim 4, characterized in that: A differential pressure flow meter is installed on the hot air duct, and the differential pressure flow meter is placed upstream of the connection between the carbon dioxide inlet pipe and the hot air duct.
6. The coal mill fire extinguishing system according to claim 2, characterized in that: An oxygen content monitor is installed on the hot air duct, and the oxygen content monitor is placed at a position of the hot air duct close to the coal mill.
7. The coal mill fire extinguishing system according to claim 1, characterized in that: The carbon dioxide intake pipe is arranged to be inclined downward.
8. The coal mill fire extinguishing system according to claim 1, characterized in that: The bottom of the coal mill is connected with a pebble coal discharge valve.
9. The coal mill fire extinguishing system according to claim 1, characterized in that: The coal mill is also connected to a steam fire extinguishing pipeline, and a temperature and pressure reducing valve is provided on the steam fire extinguishing pipeline.
10. The coal mill fire extinguishing system according to claim 9, characterized in that: A steam trap is provided on the steam fire extinguishing pipeline upstream of the temperature reduction and pressure reducing valve.