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 
  • F23C3/00—Combustion apparatus characterised by the shape of the combustion chamber
• • 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 
  • F23C6/00—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion
  • F23C6/04—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection
  • F23C6/045—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection with staged combustion in a single enclosure
• • 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 
  • F23C9/00—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber
  • F23C9/08—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber for reducing temperature in combustion chamber, e.g. for protecting walls of combustion chamber
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
  • F23L7/00—Supplying non-combustible liquids or gases, other than air, to the fire, e.g. oxygen, steam
  • F23L7/007—Supplying oxygen or oxygen-enriched air
• • 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 
  • F23C2202/00—Fluegas recirculation
  • F23C2202/20—Premixing fluegas with fuel
• • 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
  • F23C2900/03009—Elongated tube-shaped combustion chambers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E20/00—Combustion technologies with mitigation potential
  • Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Definitions

• CO 2 greenhouse gas
• Post-combustion capture ie the direct capture of CO 2 present in combustion fumes in air. This capture requires the addition of a dedicated CO 2 separation unit.
• Pre-combustion capture that is to say the prior capture of CO 2 on the feed after a first step of conversion to synthesis gas. This conversion generates a gas rich in H 2 which, once released from its carbon compounds, does not release CO 2 during its combustion.
• Oxy-combustion capture Oxygen is substituted for air for the combustion stages. Thus, at the output of the combustion equipment, high-CO 2 fumes are available which can then be sequestered directly without having to be treated in a CO 2 separation unit. On the other hand, a dedicated oxygen production unit is required.
• this latter oxy-combustion technique which concerns the present invention. Indeed this technique has many advantages: a decrease in the amount of nitrogen oxide (NOx) formed (in the case of pure O 2 , and absence of nitrogen compounds in the feed), a decrease in amount of fumes generated at iso power, a decrease in heat losses (corresponding to the "useless” heating of nitrogen through the combustion cycle), the concentration of possible pollutants such as nitrogen oxide and the oxide of As sulfur (NOx and SOx) is higher, separation is easier, most components are compressible and the heat of condensation can be used to advantage in the overall process scheme.
• NOx nitrogen oxide
• SOx oxide of As sulfur
• the patent application WO 2004/065848 relates to a device based on an oval geometry which, although promoting loop recirculation of fumes to dilute the reagents, does not allow a very good homogenization of the combustion.
• the exchange is made with tubes passing through the chamber which can disturb the recirculation.
• US Patent 7318317 discloses a turbine burner for loop recirculation of combustion gases to homogenize combustion. In this device the gases circulate only on a loop, which does not allow a homogeneous recirculation.
• the present invention therefore aims to overcome one or more of the disadvantages of the prior art by providing a specific and original arrangement to overcome the constraints specific to oxy-combustion.
• the combustion chamber therefore has a geometry allowing a natural recirculation of fumes adapted to the constraints of oxy-combustion.
• the injection is done at different points to ensure the recirculation and dilution of the reagents, which allows to obtain a distributed combustion over the entire volume of the chamber without using dedicated burners.
• the present invention provides a combustion chamber comprising an enclosure having at least one fuel injection means, at least one oxidant injection means and at least one combustion flue extraction means, wherein enclosure in the form of a tube of any section curved on itself and closed and the fuel injection means and oxidizer are disposed on the enclosure so as to be offset by an angle ⁇ , formed by each of the positions of injecting the oxidant and the fuel with the center of the enclosure, between 10 ° and 90 ° and in which the oxidant injection means is an oxidant oxidant injection means which is a gas with a concentration of oxygen greater than 90%.
• the enclosure in the form of a tube curved on itself to form a closed circle.
• the chamber in the form of a tube bent on itself so as to form an oval.
• the section of the tube is circular, oval or polygonal.
• the section of the tube is triangular.
• the fuel injection pipe forms an angle of inclination ⁇ formed by the longitudinal axis of the pipe and the straight line passing through the fuel injection point and tangent to the trajectory. the circulation of gases after the injection point, said angle ⁇ being between 5 ° and 80 °.
• the fuel injection means are formed by at least two grazing tubes arranged in opposition to the enclosure, a first pipe allowing injection from above the enclosure and a second tubing for injection from below the enclosure.
• the oxidant injection means are formed by at least one injection nozzle disposed in the radial plane of the enclosure on the outside of the enclosure.
• the oxidant injection pipe forms an angle of inclination ⁇ formed by the longitudinal axis of the pipe and the straight line passing through the fuel injection point and tangent to the trajectory. the flow of gas after the injection point, said angle ⁇ being between 5 ° and 80 °.
• the oxidant injection means are formed by at least two grainy tubes, arranged in opposition to the chamber, a first tube allowing injection from above the chamber and a second tubing for injection from below the enclosure.
• the oxidant injection pipes form an angle of inclination ⁇ ', defined with respect to the longitudinal axis of the pipe and the radial plane of the enclosure, between 5 ° and 80 th .
• the withdrawal means forms an angle Y defined with respect to the longitudinal axis of the withdrawal means and the radius of the circle formed by the chamber, and directed in the direction of circulation of the fumes. .
• the angle y is between 20 ° and 85 °.
• the tube has a section whose size is between 100 mm and 2000 mm.
• FIG. 1 is a schematic representation of a cross-section of a variant of the device according to the invention
• FIG. 2 is a schematic representation of a profile view of a variant of the device according to the invention
• FIG. 3 is a schematic representation of a longitudinal section of the variant of FIG. 2 of the device according to FIG. invention
• Figure 4 is a schematic representation of a side view of a second variant according to the invention.
• the combustion chamber comprises a housing (1) which has the shape of a tube bent on itself to form a closed circle or a closed oval.
• a tube is understood to mean an element of elongated, hollow shape, of any cross section.
• the section of the tube may be in particular circular (9), oval (FIGS. 2 and 3) or polygonal and preferably triangular (9 ! )
• the dimension d of the section of the tube (for example diameter or side) forming the enclosure is between 100 mm and 2000 mm.
• the walls of the combustion chamber are formed of specific alloy such as Haynes 230 ⁇ , Kanthal APM ⁇ or MA956 ⁇ or alloy HR120 ⁇ or any other material of the same type. Externally, these walls may be covered with materials for cooling the reactor from the outside. In this way, the outlet temperature of the chamber is adjusted and the walls are protected from hot spots generated in the chamber. In the case where the chamber would not be cooled using a dedicated device, an internal refractoring of the chamber is also possible.
• the materials used for refractoring are, for example, ceramics or refractory cements or any other material of the same type.
• the combustion chamber comprises fuel injection means (2) and oxidant injection means.
• the fuel injection means is a nozzle, and this nozzle is preferably provided with an internal ensuring the mixing of the fuel with an atomizing fluid.
• the injector is a high-speed injector making it possible to reach speeds preferably greater than 100 m / s, for example a commercial RegeMAT® injector used by WS.
• the present invention is of course not limited to these two types of fuels and also includes the use of solid fuels.
• the injector may consist of a rod in which said fuel is transported by a fluid, such as for example steam.
• the combustion chamber comprises oxidant oxidant injection means (3) which, in the context of the invention, is a gas with a very high concentration of oxygen, usually greater than 90%, or pure oxygen. .
• oxidant injection means may be an injector, preferably tubular and refractory material.
• the injection of oxidant can be assisted by any means, such as by recycled fumes, which has the advantage of accelerating the injection speed of the oxidant, limiting concentration heterogeneities due to oxygen injection. It can also be envisaged to assist the injection of oxidant with water vapor which reduces the formation of unburned solids, such as soot for example.
• the injection of the oxidant is done with a strong impulse which allows to maintain a fast flow of fumes.
• injection means are similar to tubings, that is to say circular, oval or polygonal shaped ducts, in the following description.
• One of the characteristics of the device according to the invention is that the injection and the withdrawals are done so as to limit the appearance of hot spots.
• fuel and oxidant are injected in a disjoint manner (without premixing) on the outer axis of the chamber and the angle of incidence of the tubing for injection is optimized so as to avoid any hot gas impact against the walls.
• an injection nozzle is disposed on the outside of the circle formed by the chamber, that is to say in the radial plane (P) of the enclosure.
• the angle ⁇ characterizes the inclination of the tubing and is preferably defined as the angle formed by the longitudinal axis (20) of the tubing and the straight line (21) passing through the injection point and tangent to the axis median circular (A) of the trajectory of the circulation (4) of the gases after the injection point.
• the injection means are thus formed by a system of pairs of tubings (2 ', 2 ") grazing and in opposition with respect to the radial plane (P), as illustrated in FIGS. , 3 and 4. These pipes are arranged to allow an injection from above and below the chamber, considering the section of the tube.
• the angle ⁇ 1 of these pipes is defined relative to the longitudinal axis tubing (20 ', 20 ") and the radial plane (P) of the enclosure (1).
• angles ⁇ and ⁇ ' are constrained by the construction limits and by the angle of the spray (8).
• the angle ⁇ corresponds to the inclination required to compensate for the drive and keep an injection centered in the enclosure, it is between 5 ° and 80 °, and preferably between 15 ° and 50 °.
• the angle ⁇ 1 is between 5 ° and 80 °.
• the number of tubes used is thus adjusted to increase flexibility on the flow rates without drastically changing the flow rates per nozzle.
• the number of tubings is between 1 and 15, and preferably between 2 and 10. This device also improves the fuel distribution, which improves the quality of combustion and avoid the formation of hot spots.
• the tubing (3) used is disposed on the outside of the circle formed by the chamber (1), that is to say in the radial plane of the chamber and inclined at an angle ⁇ to ensure a resulting circulation after mixing which is in the axis of the enclosure.
• This angle characterizes the inclination of the tubing and is defined as the angle formed by the longitudinal axis (30) of the tubular and the line (31) passing through the injection point and tangent to the median circular axis ( A) the trajectory of the circulation (4) of the gases after the injection point. It is between 5 and 80 ° and preferably between 15 ° and 45 °.
• an injection with 2 opposite tubes can be used. These pipes are arranged to allow injection from above and below the enclosure.
• the tubes each form an angle ⁇ '(not shown) defined with respect to the longitudinal axis of the tubing and the radial plane of the enclosure (1). This angle must be minimal to maximize the induced drive, it is between 5 ° and 80 °
• the angle ⁇ formed by each of the injection positions of the oxidant and the fuel with the center of the enclosure that is to say the angle formed by the straight lines (22, 32) passing through the points of injection of the oxidant and fuel and the center (C) of the enclosure, must be between 10 and 150 ° and preferably between 15 ° and 90 °.
• the richness defined as the quotient of the ratio of fuel / fuel flow rates in operation and the ratio Combustible / Oxidant to stoichiometry is between 0.5 and 3.
• the combustion chamber also comprises means (5) for withdrawing combustion fumes.
• This withdrawal means is disposed at a location that does not disturb the circulation of the recirculation gases (4).
• the withdrawal means (5) is thus disposed inside the circle formed by the enclosure (1), so as to perform a grazing withdrawal.
• the longitudinal axis (51) of the withdrawal pipe forms an angle Y with the radius (r) of the circle formed at the exit point of the withdrawal means.
• This extraction pipe is directed in the flue gas flow direction and the angle Y is advantageously between 20 ° and 85 °. In this way, the withdrawal is done in the extension of the circulation (4) fumes.
• the withdrawal pipe has a diameter S of between 10 mm and 250 mm.
• the oxidant is then injected with a strong impulse. This pulse helps maintain the rapid flow of fumes and additional mixing. The combustion continues throughout the course of the loop.
• Some of these fumes are extracted in an area that does not disturb the flow of fumes.
• the temperature and the composition of the fumes are substantially homogeneous throughout the enclosure. This temperature is included, in nominal operation, between 600 and 2000 ° C and preferably between 800 and 1500 0 C so as to limit the formation of NOx related to possible parasitic air inlet or to the nitrogen of the oxidizer.
• the high rate of injection of Air / O 2 of between 20 m / s and 500 m / s, and preferably between 100 m / s and 250 m / s, maintains a strong entrainment of the gases present in the combustion chamber. This strong recirculation favors the mixing and dilution of the species present so as to set up a combustion distributed as evenly as possible in the volume of the chamber.
• This provides a device that prevents the formation of hot spots and provides a combustion volume on the entire combustion chamber.
• the temperature never exceeds 2000 ° C. and the hot zones are located in the center of the chamber. torus.
• the joint effects of cooling the walls from the outside, the absence of direct impacts of hot gas and the homogeneity of the combustion make it possible to obtain wall temperatures of less than 1000 ° C.
• This arrangement (geometry of the chamber, disjoint injections, central withdrawal) promotes the recirculation of combustion fumes and a homogeneous combustion over the entire volume of the chamber.
• preheating due to the recirculation of hot fumes can extend the flexibility of operations and cover for example a wide range of wealth.
• the high surface area to volume ratio facilitates the possible cooling of the chamber and thus the control of the combustion quality via the control of the average temperature of the chamber.

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

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• 2008
  • 2008-08-13 FR FR0804606A patent/FR2935040B1/fr not_active Expired - Fee Related
• 2009
  • 2009-07-16 WO PCT/FR2009/000875 patent/WO2010018315A1/fr active Application Filing
  • 2009-07-16 EP EP09784274A patent/EP2310740A1/de not_active Withdrawn
  • 2009-07-16 CN CN200980131675.7A patent/CN102119298B/zh not_active Expired - Fee Related
  • 2009-07-16 US US13/058,676 patent/US20110185954A1/en not_active Abandoned
  • 2009-07-16 JP JP2011522534A patent/JP5530441B2/ja not_active Expired - Fee Related

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