Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C99/00—Subject-matter not provided for in other groups of this subclass
  • F23C99/001—Applying electric means or magnetism to combustion
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C99/00—Subject-matter not provided for in other groups of this subclass
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23Q—IGNITION; EXTINGUISHING-DEVICES
  • F23Q5/00—Make-and-break ignition, i.e. with spark generated between electrodes by breaking contact therebetween
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C2700/00—Special arrangements for combustion apparatus using fluent fuel
  • F23C2700/06—Combustion apparatus using pulverized fuel
  • F23C2700/063—Arrangements for igniting, flame-guiding, air supply in
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
  • F23C2900/00—Special features of, or arrangements for combustion apparatus using fluid fuels or solid fuels suspended in air; Combustion processes therefor
  • F23C2900/99005—Combustion techniques using plasma gas

Definitions

• the invention relates to energy and can be used in thermal power plants, boiler houses, etc. to optimize and control the combustion process and ensure the ignition of boilers and stabilize the combustion of fuel, for example, coal dust, during its flaring without the use of additional highly reactive fuel.
• N ° RU2059926Cl (IPC F23D 1/00, F23Q 13/00; published on 05/10/1996), which is a fuel flaring device, is known.
• This device contains a channel for supplying fuel mixture, a secondary air channel with a swirl installed in it, a plasma torch igniter with rod electrodes.
• This device is characterized in that the plasmatron-igniter with rod electrodes is installed in the feed mixture, the electrodes are made of graphite and placed along the entire length of the feed mixture, and the plasmatron-igniter is equipped with double-flow nozzles and installed with the possibility of longitudinal movement between the rod electrodes, the plasma torch nozzles are oriented at the ends of the electrodes.
• This device comprises a housing, rod electrodes connected to a source of high-frequency alternating current, for generating an electric arc, a channel for supplying fuel mixture and a secondary air channel, according to the invention, the housing is divided into an ignition chamber and a cooling chamber, wherein the secondary air passage is installed in the cooling chamber with installed in it with rod electrodes.
• the disadvantage of this device is the limited thermal power of the initiated flare and the impossibility of organizing the optimal process of burning the entire volume of fuel, since the design of the known device is focused only on the creation of the initiating flare.
• the supply of secondary air to the ignition chamber also limits the volume of flammable pulverized coal due to the need to increase air volumes and, as a consequence, the values of the flow rate of the mixture are unacceptable, in terms of flame separation.
• the disadvantages of this device include the low reliability of ignition of low-reactive fuels (lean, ballasted and watered fuels, such as coal water). This is primarily due to the subsequent ignition of the main torch from the received torch. When burning fuel with a high degree of slag formation, slagging of the surfaces of the ignition chamber can occur, which requires constant maintenance. This leads to a decrease in the reliability of the ignition system.
• the objective of the claimed invention is to provide a device and method that would be able to provide stable ignition and efficient combustion of the entire amount of pulverized coal supplied to the burners of the boiler, with reduced requirements for combustible fuel (ballasted, lean, waterlogged coal), and temperature fuel and air supplied to the burner, which ensures that the boiler starts up from a cold state with cold components and with minimal electrical energy consumption without the use of a high reaction nnogo fuel. That ensures the reliability of the boilers and the safety of the processes of kindling and fuel combustion.
• the technical result of the claimed invention is the possibility of flaring fuel, including low reaction, and increasing the efficiency of its combustion.
• the efficiency of fuel combustion is understood to mean the generation of thermal energy with its minimum losses (minimum excess air, that is, close to the stoichiometric value, as well as minimal chemical and mechanical underburning of the fuel).
• the fuel flaring device comprises an ignition chamber, an alternating current source, at least two rod electrodes connected to an alternating current source, a fuel mixture supply channel, a secondary air channel and a cooling chamber, between the chamber Ignition and cooling made passages for the installation of rod electrodes.
• the inventive device for flaring fuel is characterized in that at least one of the rod electrodes is connected, relative to the shell of the ignition chamber, a constant voltage source, and at the output of the ignition chamber a torch forming chamber is installed, to which a secondary air channel is connected. This device design allows the excitation of a diffuse electric discharge between the electrodes, which produces ionization and ignition of the fuel mixture.
• a highly ionized pre-flame zone of the torch is formed, which is the main condition for ensuring heterogeneous chemical reactions of oxidation of the fuel mixture, which makes it possible to efficiently burn low-reaction fuel, i.e., the oxidation reaction, which has a high chemical reaction rate.
• the presence of at least one rod electrode, connected to it, relative to the shell of the ignition chamber, with a constant voltage source, allows you to maintain a highly ionized state of the pre-flame zone of the torch and to ensure that the necessary conditions for the complete combustion of the fuel mixture during its flaring are fulfilled.
• the presence of a secondary air channel connected to the torch forming chamber ensures the formation and burning of the torch in the furnace by supplying secondary air to the torch forming chamber through the secondary air channel.
• the rod electrodes are mounted on heat and conductive racks, the other end of which is mounted on support plates placed in the cooling chamber in isolation relative to the conductive surfaces of the device. This allows, on the one hand, to reliably fix the rod electrodes, and on the other hand, to remove excess heat from the rod electrodes and base plates. This leads to an increase in the life of the rod electrodes, increasing the reliability of the device for efficient combustion of low-reaction fuel.
• the cooling chamber is provided with a channel for supplying sealing air, and the secondary air is supplied to the flare chamber.
• This allows you to remove heat from the rod electrodes by supplying sealing air to the cooling chamber, which leads to efficient heat removal from the electrodes of the device, which increases the reliability of the device for efficient burning of low reaction fuel.
• the supply of secondary air to the chamber of the formation of the torch ensures optimal formation of the torch and, as a result, the efficiency of burning low-reactive fuel using the inventive device for flaring fuel.
• the technical result is achieved using the method of burning pulverized coal, which consists in creating an electric arc discharge in the ignition zone, supplying the air-fuel mixture to the ignition zone, igniting the air-fuel mixture in the ignition zone, creating a diffuse electric discharge, acting on the diffuse electric discharge on the border zone of flame formation and carry out flaring of fuel, while setting the value of the electrostatic potential border zone of flame formation at a given level, providing the required parameters of fuel combustion during its flaring.
• FIG. 1 is a schematic diagram of a device for flaring fuel
• FIG. 2 is a schematic diagram of an ionization block
• the present invention is directed to a device and method that would be able to provide stable ignition and efficient burning of the entire amount of pulverized coal supplied to the burners of the boiler, with reduced requirements for combustible fuel (ballasted, lean, watered coals), and temperature the supplied fuel and air to the burner, which ensures the start-up of the boiler from a cold state with cold components and with minimal energy consumption without the use of highly reactive fuel.
• a fuel mixture is a mixture of air or an oxidizing gas, for example, oxygen, and fuel.
• the fuel used can be in any aggregate state (solid, liquid or gaseous), however, the necessary condition is the size of the particles or drops of fuel, if solid or liquid fuel is used as a component of the fuel mixture, respectively.
• the particle size for solid fuels should not exceed 60 microns.
• the droplet size should not exceed 10 microns.
• solid fuels that can be used as a component of air mixtures are coal, peat, wood waste, etc.
• liquid fuels that can be used as a component of air mixtures are petroleum products, coal-water fuels, etc.
• an alternating current source of any known design can be used, for example, a commercially available converter of the power source of a plasma generator IRBI943-5.4 UHL3.1V.
• a constant voltage source 5 a constant voltage source of any known design can be used, for example, a commercially available high voltage source, built according to the voltage multiplication scheme, IVNR-5/50.
• the ionization unit 2 contains an ignition chamber 6, a cooling chamber 7, rod electrodes 8 mounted on current and heat-conducting racks 9, supporting insulators 10 mounted outside the ignition chamber 6, which serve as a support for the plate 11 connected by fasteners 12 to insulators 10 and stand 9.
• the cooling chamber 7, which is hermetically sealed passages are made for the electric cable 13, passage 14 for introducing cooling air and passage 15 for racks 9.
• the feed channel of the fuel mixture 1 may be made of any known structural material, for example, steel.
• the ionization unit 2 can be made of any known conductive structural material, for example, steel.
• the rod electrodes 8, the racks 9 and the support plate 11, in turn, can be made of any known current-conducting and heat-conducting material, for example, copper or bronze.
• the chamber forming the torch 3 can be made of any known heat-resistant material. As an example, the torch forming chamber 3 can be made of heat-resistant alloy steel, for example, steel grade X20H35.
• the torch forming chamber 3 may have an internal high temperature thermal insulation coating made using any known refractory material, for example, material made on the basis of chamotte powder, refractory clay, etc., resistant to temperature in the temperature range, the upper limit of which reaches 1500 ° C - 1700 ° C.
• the ignition chamber 6 through the channel 1 for supplying the fuel mixture serves prepared aerosol mixture of fuel.
• AC voltage is applied to the rod electrodes 8 in the frequency range 1-30 kHz, the breakdown of the interelectrode space occurs, as a result of which the electrical circuit is closed.
• a diffuse electric discharge is excited, which produces ionization and ignition of the fuel mixture.
• a highly ionized pre-flame zone of the torch is formed, which is the main condition for ensuring heterogeneous chemical reactions of oxidation of the entire volume of the fuel mixture.
• the diffusion discharge acquires an equal electrostatic potential, which provides the required electrostatic potential of the pre-flame zone.
• a change in this potential a change in the intensity of the ionic wind takes the flame products of combustion into the ignition zone and supports the processes of fuel ignition along with chemical processes in the highly ionized regions of the diffuse discharge and the flame zone of the flame.
• the potential of the pre-flame zone of ignition decreases, while the concentration of charges in the pre-flame zone of the torch, the amount of ionic wind and, as a result, the intensity of the torch burning up to its extinction decrease.
• Ensuring the occurrence of heterogeneous chemical processes is the main condition for burning low-reactive fuels, including coal-water fuels.
• at least one rod electrode 8 is supplied with an electrostatic potential from a constant voltage source 5 relative to the conductive surface of the ignition chamber 6.
• the ignition chamber 6 can be made as part of the channel 1 for supplying the fuel mixture.
• the ignited aerosol mixture enters the torch formation chamber 3, where the main chemical processes take place.
• the formed torch containing highly activated components of the fuel and the oxidizing agent enters the furnace of the boiler, in which the complete combustion of the fuel is carried out.
• the range of variation of the electric potential is in the range from 0, 1 to 5 kV.
• the frequency of operation of the AC source 4 is selected from the conditions for ensuring a stable diffuse discharge and technical limitations associated with the technical implementation, is in the range of 3-50 kHz.
• the amplitude value of the current should be in the range of 0, 1 - 2 A, which ensures the durability of the rod electrodes 8 without replacing them.
• the claimed invention is technologically advanced and easy to use and manufacture.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)

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Citations (7)

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• 2019
  • 2019-05-15 EP EP19802532.2A patent/EP3627047B1/de active Active
  • 2019-05-15 RS RS20230966A patent/RS64712B1/sr unknown
  • 2019-05-15 WO PCT/RU2019/050061 patent/WO2019221640A1/ru active Application Filing

Patent Citations (7)

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