JP2015510577A - High temperature FGR ultra-low NOx combustion system using Coanda effect - Google Patents

Abstract

A high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect is provided. The present invention relates to a high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect. More specifically, the combustion gas generated in the combustion chamber is circulated, and mixed with the air flow and then re-entered into the combustion chamber in the form of a mixed gas. By doing so, the combustion target substance or air stream is heated to the ignition temperature of the incineration object within a short time, and at the same time, the oxygen concentration is diluted to reduce NOx and carbon monoxide and Although the CO2 emission is reduced, the structure of the Coanda nozzle and the air supply unit using the Coanda effect is used so that the high-temperature combustion gas is attracted secondarily around the Coanda nozzle and By having a structure in which air is secondarily attracted on the side, a sufficient amount of high-temperature combustion gas intake for mixing air flow and high-temperature combustion gas can be achieved. At the same time, as the structure of the combustion chamber to allow existing contrast a small production, large cost savings in such footprint, including the manufacturing costs related to hot FGR ultra-low NOx combustion apparatus Coanda effect having an effect. [Selection] Figure 6

Description

  The present invention relates to a high-temperature FGR ultra-low NOx combustion apparatus having a structure capable of attracting and mixing air and high-temperature combustion gas twice each and using the Coanda effect capable of simultaneously reducing NOx and CO.

  In general, in the case of an existing burner using air as an oxidant, when the temperature is measured along the central axis of the burner as shown in FIG. 1, the temperature is approximately 2000K as shown in the drawing as “heat spot”. There is a high temperature region that is reached. Since nitrogen oxides (NOx) are intensively generated very quickly (in the milli second range) in this high temperature zone, lowering this high temperature region is a very important method for realizing low NOx combustion.

  Recently, in order to increase energy efficiency, a method of recovering the heat of the combustion gas by using a heat exchanger and preheating the air is used. In this case, the maximum temperature of the flame (Peak temperature) further increases. As a result, the NOx generation rate is further increased. Therefore, there is a need for a technique that prevents the maximum temperature of the flame zone from increasing even when air is preheated.

  As shown in FIG. 2, when the oxygen concentration is high at 7% in a burner using an existing combustion system, the maximum temperature of the flame is greatly increased when the air is preheated at 1200K and when the air is preheated at 1600K. It can be seen that this greatly increases the production of NOx.

  However, when the oxygen concentration is low, even if the air is preheated at 1600K, the maximum temperature of the flame is greatly reduced, and at the same time, the temperature of the downstream portion where the temperature is low rises, and the temperature generally tends to be leveled. Show. Ultralow NOx combustion can be implemented using such a method.

  In order to reduce the oxygen concentration in this way, a method is used in which the combustion gas after the fuel is burned is returned and mixed into the air stream. However, when the combustion gas after being cooled is recirculated as illustrated in FIG. 3, the region where the flame is stabilized is greatly narrowed, and if the amount of the recirculated combustion gas is increased, Becomes unstable or disappears. Therefore, if the combustion gas is recirculated while maintaining a high temperature state, a very stable flame region labeled MILD mode in FIG. 3 appears.

  That is, the combustion air is heated above the ignition temperature of the fuel, the combustion gas is recirculated, mixed and diluted, thereby reducing the oxygen concentration and simultaneously maintaining the high temperature, thereby stabilizing the flame. The combustion method to be maintained is MILD combustion (Moderate and Intense Low Oxygen Dilution).

  Such MILD combustion method is called various names, but in Japan, where development has been advanced, a heat exchanger is used to recirculate the combustion gas and increase the temperature of the air as shown in FIG. Use. However, in order to raise the temperature of the air above the ignition temperature of the fuel, generally 1000 ° C. or more, it is impossible with a general heat exchanger, and as shown in FIG. Must be used. The heat storage regenerative heat exchanger uses a method in which high-temperature combustion gas passes through the ceramic heat-storage material, heats it at a high temperature, and then flows air again from the heat-storage material side to obtain a high temperature. In order to make the air flow alternately, a 4-way switching valve that can withstand high temperatures is used. (Since this method of heating air at a high temperature is used, in Japan, this is called high temperature air combustion (HiTAC)). Therefore, there is a problem that the apparatus becomes complicated and the price is high. It was.

  In addition, when looking at the method of attracting high temperature combustion gas from the low pollution combustion equipment to reduce carbon monoxide (CO) and nitrogen oxide (NOx) at the same time to the air classification, it has been combined with the air nozzle so far A Venturi type mixing tube was used.

However, in the above method, the center of the air nozzle part and the venturi mixing pipe should be combined in a straight line, and if the length of the venturi mixing pipe is not secured to a certain level or more, a negative pressure for attracting high temperature combustion gas is generated. In some cases, the wall thickness of the combustion chamber is increased. If the wall of the combustion chamber becomes thicker, the width of the entire combustion chamber will be further increased along with the passage and width through which the high-temperature combustion gas flows, which will increase the installation area, which will increase the cost. was there.

Korean Published Patent No. 10-2009-0127046 Japanese Patent No. 2655555

  The present invention has been devised to solve the above-mentioned problems, and the object of the present invention is to provide a high-temperature combustion gas without a separate heat exchanger for heating air at a high temperature as in the existing technology. By having a structure that recirculates the gas, heat and inactive combustion gas are recirculated at the same time, thereby diluting the air flow and simultaneously heating the air flow at a high temperature, thereby realizing MILD combustion. The present invention is to provide a high-temperature FGR ultra-low NOx combustion apparatus that uses the Coanda effect.

  In addition, because of the Coanda effect that flows along a curved surface, the present invention can form a Coanda nozzle and an air supply unit so that a sufficient amount of high-temperature combustion gas for mixing with air can be sucked, but the combustion chamber An object of the present invention is to provide a high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect so that the wall thickness can also be reduced to reduce the installation area and the manufacturing cost.

  In addition, an auxiliary induction mixing hole is formed at the outer periphery of the nozzle of the Coanda effect for mixing high temperature combustion gas and air, and the outside air is supplied twice by the induced high temperature combustion gas, and the discharged mixed gas The object of the present invention is to provide a high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect in which high-temperature combustion gas is additionally attracted and mixed.

As a means for solving the above-mentioned problems, the present invention has a combustion chamber 10 in which a large number of air injection holes 11 are formed at the outer peripheral edge, and a combustion target substance is combusted inside the outer peripheral edge of the combustion chamber 10. A housing 20 that forms a gas flow passage 21 with the combustion chamber 10 so that the high-temperature combustion gas combusted in the combustion chamber 10 flows; The auxiliary inductive mixing hole 43 is formed between the air injection hole 11 and the air injection hole 11 so that the high temperature combustion gas is attracted to the inside by the air injected into the air injection hole 11 and the high temperature combustion is performed. And a Coanda nozzle 40 for allowing the gas to be mixed with air and re-entered in the combustion chamber 10; and an air supply unit 50 for injecting air into the Coanda nozzle 40. .

  As described above, the present invention has the effect of attracting a sufficient amount of high-temperature combustion gas to the air flow without securing the lengths of the air nozzle and the venturi mixing tube that have been used in the combustion apparatus so far.

  Also, unlike the present invention, the present invention has a Coanda nozzle and an air supply part structure communicating with the Coanda nozzle, so that the wall of the combustion chamber can be reduced by 30% or more compared to the existing, and the manufacturing cost, installation cost, installation There is an effect that the area can be reduced.

  In addition, the present invention can attract a relatively large amount of combustion gas as compared with the venturi mixing tube used in the existing combustion apparatus, so that it is easy to reduce the concentration through dilution of oxygen and maintain the air flow at a high temperature. effective.

  In addition, the present invention has an effect that the intake amount of the induced combustion gas can be easily adjusted through the supplied air flow velocity.

  In addition to the NOx reduction effect, the present invention has the effect of increasing the flame stabilization and CO reduction effects.

  In addition, even if the amount of primary air supplied into the Coanda nozzle is reduced in the present invention, secondary air is attracted together, so that air necessary for combustion can be applied, and a blower for supplying primary air can be used. There is an effect that the capacity can be selected small.

  Further, according to the present invention, the secondary high-temperature combustion gas is additionally attracted and mixed around the Coanda nozzle, so that the temperature of the mixed gas can be further increased, and the flame stabilization and CO reduction effects can be enhanced. At the same time, the oxygen concentration in the air can be further diluted, the maximum temperature of the flame can be further lowered, and the NOx reduction effect can be maximized.

  In addition, by adjusting the amount of air supplied primarily and the amount of air supplied additionally to the secondary, the most efficient combustion condition can be created.

The conceptual diagram of one Example which showed the basic concept of ultra-low NOxMIL combustion. Graph showing the oxygen concentration and temperature distribution at the highest temperature on the burner center line. The graph of one Example which showed the appearance area of ultra-low NOx MLD combustion. The conceptual diagram of one Example which showed the recirculation structure of the heat and combustion gas for the implementation of MILD combustion conventionally used. The block diagram which showed the high temperature air system low NOx combustion apparatus using the thermal storage regeneration type | mold high temperature heat exchanger used conventionally. The front sectional view of one example showing the structure of the Coanda nozzle and air supply part concerning the present invention. 1 is a cross-sectional view of a first embodiment to which a high temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to the present invention is applied. Sectional drawing of the 2nd Example to which the high temperature FGR ultra-low NOx combustion apparatus using the Coanda effect based on this invention was applied. Sectional drawing of 3rd 1st Example to which the high temperature FGR ultra-low NOx combustion apparatus using the Coanda effect based on this invention was applied. Sectional drawing of 3rd 1st Example to which the high temperature FGR ultra-low NOx combustion apparatus using the Coanda effect based on this invention was applied. 4 is a cross-sectional view of a fourth embodiment where a high temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to the present invention is applied. FIG.

DESCRIPTION OF SYMBOLS 10: Combustion chamber 11: Air injection hole 12: Fuel supply part 13: Burner 20: Housing 21: Gas flow path 22: Chimney 23: Ram pusher 30: Detour pipe 40: Coanda nozzle 41: Fluid furnace 42: Protrusion part 43: Auxiliary attracting and mixing hall 50: Air supply part 51: First control valve 52: Air head 60: Discharge part 61: Discharge line 62: Observation window 70: Auxiliary air supply part 71: Second control valve

  Before describing various embodiments of the present invention in detail, it is not intended that the application be limited by the details of the arrangement and arrangement of components set forth in the following detailed description or illustrated in the drawings. I understand. The present invention may be embodied and implemented in other embodiments and may be carried out in various ways. Also, the orientation of the device or element (eg, “front”, “back”, “up”, “down”, “top”, “bottom”) ”,“ Left ”,“ right ”,“ lateral ”), etc., the expressions and terminology used herein are merely for the purpose of simplifying the description of the invention. Used, does not indicate or imply that the associated device or element simply has a specific orientation.

In order to achieve the above object, the present invention has the following features.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and claims should not be construed to be limited to ordinary or lexicographic meanings, and the inventor will describe his invention in the best possible manner. Therefore, based on the principle that the concept of terms can be appropriately defined, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

  Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention. It should be understood that there are various equivalents and variations that can be substituted at the time of this application.

To this end, if an embodiment of the present invention is examined,
In the first embodiment, a plurality of air injection holes 11 are formed in the outer peripheral edge, and a combustion chamber 10 in which a combustion target substance is combusted; spaced apart from the outer peripheral edge of the combustion chamber 10; A housing 20 that forms a gas flow passage 21 with the combustion chamber 10 so that the combusted high-temperature combustion gas flows; the air injection hole 11 is separated from the inner peripheral edge of the air injection hole 11. The auxiliary induction mixing hole 43 is formed between the air injection hole 11 and the high-temperature combustion gas is attracted to the inside by the air injected into the inside, and the high-temperature combustion gas is mixed with the air. The Coanda nozzle 40 is made to re-flow at 10; and the air supply section 50 for injecting air into the Coanda nozzle 40.

  In the second embodiment, a large number of air injection holes 11 are formed in the outer peripheral edge, and a combustion chamber 10 in which a combustion target substance is combusted; spaced apart from the outer peripheral edge of the combustion chamber 10, A housing 20 that forms a gas flow passage 21 therebetween; a bypass pipe 30 that communicates the gas flow passage 21 and the discharge part 60 of the combustion chamber 10; an internal space in the bypass pipe 30 that is separated from the inner periphery of the bypass pipe 30. The auxiliary induction mixing hole 43 is formed between the bypass pipe 30 and the high temperature combustion gas is attracted to the inside by the air injected into the inside, and the high temperature combustion gas is mixed with the air. The Coanda nozzle 40 is configured to be re-flowed in the air; and an air supply unit 50 for injecting air into the Coanda nozzle 40.

  Also, a combustion chamber 10 in which a combustion target substance is combusted; spaced from the outer peripheral edge of the combustion chamber 10 and between the combustion chambers 10 so that the high-temperature combustion gas combusted in the combustion chamber 10 flows. A gas flow passage 21 is formed in the gas flow passage 21 so as to be separated from the inner periphery of the gas flow passage 21, and an auxiliary induction mixing hole 43 is formed between the gas flow passage 21 and the housing 20. A Coanda nozzle 40 that causes air injected into the interior to attract combustion gas therein, and allows the mixed gas of the high-temperature combustion gas and air to reflow into the combustion chamber 10; And an air supply unit 50 for injecting air.

  In addition, the Coanda nozzle 40 is formed with a perforated flow furnace 41 having a gentle slope in the length direction, and the flow furnace 41 is provided with a protruding portion 42 having a reduced diameter. Features.

  Further, the air supply unit 50 injects air from the projecting portion 42 side of the fluidized furnace 41 toward the discharge direction of the mixed gas, so that the injected air flows along the wall surface of the fluidized furnace 41. The hot combustion gas is attracted and sucked in the injection direction.

Further, when the mixed gas is discharged from the Coanda nozzle 40, the auxiliary attracting and mixing hole 43 is further attracted and mixed with the high temperature combustion gas through the auxiliary attracting and mixing hole 43 through the discharge of the mixed gas. It is characterized by that.

  The air injection hole 11 forms a preset angle with the inner wall of the combustion chamber 10.

  In addition, a large number of the Coanda nozzles 40 are installed in the bypass pipe 30, and air and high-temperature combustion gas are mixed in advance from the bypass pipe 30 and then supplied to the combustion chamber 10 in a mixed gas form. It is characterized by that.

  Further, the air supply unit 50 is provided with a first control valve 51 for each air supply unit 50 so that the flow rate and the opening / closing amount of the injected or injected air are individually controlled. It is characterized in that the intake amount of the high-temperature combustion gas that is inhaled by air is adjusted.

  Further, the high temperature combustion gas is installed on the Coanda nozzle 40 on the side where the high temperature combustion gas is introduced, and when the high temperature combustion gas is attracted by the air supply unit 50, the outside air outside the air supply unit 50 is further attracted. A plurality of auxiliary air supply units 70;

  The plurality of auxiliary air supply units 70 are each provided with a second control valve 71 so that the flow rate and opening / closing amount of the injected or injected air are individually controlled, thereby being guided by the air. The intake amount of the high-temperature combustion gas to be sucked is adjusted.

Hereinafter, a high temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to a preferred embodiment of the present invention will be described in detail with reference to FIGS.
As illustrated, a low pollution combustion apparatus using a high temperature FGR (Fluid Gas Recirculation) to which the Coanda effect air supply unit according to the present invention is applied includes a Coanda nozzle 40 and an air supply unit 50, It has a combustion apparatus 100, a combustion apparatus 200, a combustion apparatus 300, and a combustion apparatus 400 according to four embodiments having a Coanda effect for high-temperature combustion gas suction.

  First, prior to describing the four embodiments, the description of the Coanda nozzle 40 and the air supply unit 50 will be given priority.

  The Coanda nozzle 40 has a tubular shape in which the fluidized furnace 41 is perforated and formed in the inner length direction, and the interior is vacant. Furthermore, the fluidized furnace 41 has a Coanda effect in a direction in which an air flow through an air supply unit 50 to be described later or a high-temperature combustion gas (exhaust gas) discharged from the combustion chamber 10 is sucked. In other words, the diameter of the fluidized furnace 41 in the Coanda nozzle 40 gradually increases from one side to the other side (direction in which the air flow moves).

  More specifically, the fluidized furnace 41 has a configuration in which the diameter is abruptly narrowed from one side to the other side of the fluidized furnace 41, and the diameter gradually increases with a gentle inclination in the length direction. . The portion where the diameter is the narrowest in the fluidized furnace 41 can be said to be the protruding portion 42.

  The air supply unit 50 supplies air to the inside of the Coanda nozzle 40 described above, and the supplied air can move in one direction of the Coanda nozzle 40, so that the air supply unit 50 can be used as a Coanda nozzle. After being installed in the 40-thick portion, air is supplied into the fluidized furnace 41 by making one end communicate with the fluidized furnace 41 of the Coanda nozzle 40.

  At this time, one end of the air supply unit 50 communicates from the side of the projecting portion 42 projecting inward so that the diameter of the fluidized furnace 41 in the Coanda nozzle 40 is minimized. The air flow is communicated from the side in the direction in which the air flow should flow (ex: a direction having a gentle inclination and a gradually increasing diameter (a direction from one side of the fluidized furnace 41 to the other side)).

  That is, when the air supply unit 50 injects air, the air is supplied from the projecting portion 42 side of the fluidized furnace 41 toward the other side surface of the fluidized furnace 41, and the airflow thus supplied is the Coanda effect. Thus, the fluidity is made to flow in one direction in close contact with the fluidized furnace 41 having the gentle inclination.

  The above-mentioned “Coanda effect” means that the airflow is close to the wall surface, and the jetted airflow adheres to the surface and has a tendency to flow, and the Coanda nozzle 40 is formed as shown in FIG. Then, since the classification of the supplied air flows along the curved surface of the flow furnace 41 of the Coanda nozzle 40, a negative pressure is formed, and this is caused by the Coanda nozzle 40 from one side of the Coanda nozzle 40. High-temperature combustion gas flowing in a direction different from the air flow can be attracted to the Coanda nozzle 40 side. In other words, when the above-described Coanda nozzle 40 and the air supply unit 50 are applied, the amount of high-temperature combustion gas attracted can be increased five times or more compared to the amount of injected air. If it is used for combustion, the temperature of air can be effectively heated in a short time, and at the same time, the inert gas and carbon dioxide components in the combustion gas can be mixed to dilute the air and reduce the oxygen concentration. It eliminates the hot flame zone, makes the flame temperature uniform, greatly reduces NOx generation, and at the same time stabilizes the flame by the air flow heated above the ignition temperature of the fuel. Will be reduced.

  Further, the air supply unit 50 is naturally proportional to the number of Coanda nozzles 40 used, and the first control valve 51 is individually installed for each air supply unit 50 to perform injection or The flow rate and opening / closing amount of the injected air can be individually controlled, but such control eventually has the effect of adjusting the intake amount (supply amount) of the high-temperature combustion gas that is flow-inspired by the injected air. It is to have.

  In the unlikely event that the first control valve 51 is not installed for each of the air supply units 50 and the inflow amount of air is controlled in one place, the air flow in which the inflow amount is controlled in this way is used. If the air supply unit 50 is divided and supplied, if the air flow rate through the air supply unit 50 and the Coanda nozzle 40 is not constant or the speed decreases, one side of the Coanda nozzle 40 It is difficult to suck into the Coanda nozzle 40 the combustion gas flowing in a direction different from the air inflow direction from the air, and even if the combustion gas is sucked, the combustion of the sucked chimney 22 (pipe from which the combustion gas is discharged) Due to the gas discharge flow rate, there arises a problem that the chimney 22 is scraped again. On the other hand, the 1st control valve 51 is individually installed for every air supply part 50 so that the above problems may not occur.

  Hereinafter, four examples of the combustion apparatus 100 (shown in FIG. 7) and the combustion apparatus 200 (shown in FIG. 8) to which the Coanda effect is applied via the Coanda nozzle 40 and the air supply unit 50 having the above-described structure. The combustion apparatus 300 (illustrated in FIGS. 9 and 10) and the combustion apparatus 400 (illustrated in FIG. 11) will be described.

The first embodiment, as illustrated in FIG.
FIG. 7 shows a MILD combustion furnace capable of burning all of gas, liquid, and solid fuel. A high-temperature combustion gas flows outside the combustion chamber 10 and is arranged in a tangential direction of the combustion chamber 10. The structure is such that a high-temperature combustion gas mixture attracted by air and an air flow is supplied to the inside of the combustion chamber 10 while being swirled through the Coanda nozzle 40.

  The combustion chamber 10 is formed with a fuel supply part 12 into which a combustion target substance is introduced on one side, and the combustion target substance introduced therein is heated from the inside by a burner 13 or the like and burned. A large number of air injection holes 11 are formed around the outer peripheral edge of the chamber 10 in the longitudinal direction. Such a large number of the air injection holes 11 serve to communicate the inside of the combustion chamber 10 with a gas flow passage 21 described later.

Further, the air injection holes 11 of the combustion chamber 10 may have different diameters of the perforations according to various embodiments of the user. The diameter may gradually become smaller or larger toward the vertical direction, and may be formed at a preset angle (predetermined angle) with the inner wall of the combustion chamber 10. The injection hole 11 can also be formed in the tangential direction of the inner wall of the combustion chamber 10.
(Furthermore, if the same amount of air is supplied over the entire length of the combustion chamber 10, combustion may occur at one time from one side of the combustion chamber 10, so combustion from a location close to the fuel supply unit 12 occurs. The chamber 10 increases the size of the air injection holes 11 one after another in the length direction, or adjusts the amount of air supplied through each air injection hole 11 (through the first control valves 51 described above). ) To adjust the combustion speed in the combustion chamber 10.)

  A housing 20 made of a refractory material is installed outside the combustion chamber 10, and the housing 20 is installed at a predetermined interval on the outer periphery of the combustion chamber 10, so A gas flow passage 21 is formed between the outer peripheral edge and the inner peripheral edge of the housing 20.

  Further, on the other side of the housing 20, an observation window 62 that allows the inside of the combustion chamber 10 to be confirmed from the outside, and combustion residues (Ash, C) generated inside the combustion chamber 10 are discharged. A discharge portion 60 in which a discharge line 61 is formed may be further provided, and the inside of the discharge portion 60 is configured to communicate with the combustion chamber 10 and the housing 20.

  As a result, the high-temperature combustion gas generated in the combustion chamber 10 flows from the other side of the combustion chamber 10 to the gas flow passage 21 through the discharge portion 60 and then communicates with the gas flow passage 21. It is structured to be discharged to the outside through a chimney 22 (chimney) of the housing 20.

In the first embodiment, the Coanda nozzle 40 and the air supply unit 50 described above are respectively installed in a large number of air injection holes 11 formed on the outer peripheral edge of the housing 20.

  At this time, the size of the Coanda nozzle 40 provided in the air injection hole 11 is relatively smaller than the size of the air injection hole 11, and the Coanda nozzle 40 is longer than the air injection hole 11. The inner peripheral edge of the air injection hole 11 and the outer peripheral edge of the Coanda nozzle 40 are separated so as not to contact each other.

  That is, the Coanda nozzle 40 is not completely sandwiched in correspondence with the air injection hole 11, but is provided in the air injection hole 11 so as to be spaced apart from the air injection hole 11. An auxiliary attracting and mixing hole 43 is formed around 40 (between the inner peripheral edge of the air injection hole 11 and the outer peripheral edge of the Coanda nozzle 40).

  As a result, the high-temperature combustion gas discharged after being combusted from the combustion chamber 10 flows into the gas flow passage 21, and the high-temperature combustion gas flown in the gas flow passage 21 enters the air injection holes 11. By the air injected and supplied toward the combustion chamber 10 in the Coanda nozzle 40 provided, the air is attracted and sucked into each Coanda nozzle 40 in each air injection hole 11 and mixed with the air. It is to be re-entered into the combustion chamber 10 in a mixed gas form.

  Further, when the air and the high-temperature combustion gas are mixed and discharged to the other side of the Coanda nozzle 40 as described above, the discharge of such a mixed gas causes the high temperature also through the auxiliary induction mixing hole 43 around the Coanda nozzle 40. Combustion gas is introduced, and the Coanda nozzle 40 is further mixed with the mixed gas discharged inside. In other words, the air injected into the Coanda nozzle 40 is called primary air, and the high-temperature combustion gas that is attracted and mixed while the primary air moves to the other side of the Coanda nozzle 40 is the primary combustion gas. When the primary mixing classification (primary mixed gas) is such that the primary air and the primary combustion gas are mixed and mixed in the Coanda nozzle 40 in this way, the primary mixing classification (mixed gas) is the Coanda nozzle 40. When discharged from the other side, the high temperature combustion gas (secondary combustion gas) is secondarily generated through the auxiliary induction mixing hole 43 around the Coanda nozzle 40 by the mixed gas discharge force of the Coanda nozzle 40 discharged. It will be further attracted and mixed to form a secondary mix classification, further diluting the oxygen concentration in the air and at the same time being heated at high temperatures and used for combustion To reduce NOx and CO at the same time, it is possible to stabilize the flame. In other words, since the secondary high-temperature combustion gas is further attracted around the Coanda nozzle 40, the temperature of the mixed gas (mixed classification) can be further increased, and the flame stabilization and the CO reduction effect can be enhanced. it can.

  Further, an auxiliary air supply unit 70 is further provided on one side of the Coanda nozzle 40 (the side on which the mixed gas is discharged is the other side). When air (primary air) is supplied into the Coanda nozzle 40, high-temperature combustion gas is attracted and sucked from one side of the Coanda nozzle 40 in the primary air injection direction. At the same time, high-temperature combustion gas is sucked into and attracted to the inside of the Coanda nozzle 40, and external air (outside air) passes through the auxiliary air supply unit 70 installed on one side of the Coanda nozzle 40. It is designed to be attracted by being sucked inside. (For this reason, it is natural that one side of the auxiliary air supply unit 70 communicates with the outside of the combustion chamber 10.) Further, such a side installed on one side of many Coanda nozzles 40, respectively. Since the second control valve 71 is also individually installed in the auxiliary air supply unit 70, the amount of secondary air attracted is adjusted, and the efficient combustion conditions are adjusted together with the first control valve 51. . That is, in the case of the primary air through the air supply unit 50, if the air is supplied using a separate air blower, the auxiliary air (secondary air) is supplied to the auxiliary induction mixing hole 43 only by supplying the air supply unit 50. (Subsequent air) can be further attracted, even if the amount of air supply through the air supply unit 50 is small, the auxiliary air through the auxiliary induction mixing hole 43 during the air supply of the air supply unit Since the air necessary for combustion may be applied by attracting air, the blower (ex) used in the air supply unit 50 for supplying primary air is more than the case where only the air supply unit 50 is formed. : The effect of being able to be selected with a small capacity.

Therefore, fuel is supplied into the combustion chamber 10 preheated above the ignition temperature of the fuel by such a combustion apparatus of the present invention, and high-temperature combustion gas is recirculated and mixed into the classification of air (oxidant). By burning, if a high-temperature portion concentrated in the flame zone does not occur without a separate heat exchanger for preheating air at a high temperature, the air is dispersed at an even temperature over the entire surface of the combustion chamber 10. By achieving MILD combustion, it has the effect of minimizing the generation of CO and NOx, at the same time increasing the thermal efficiency and reducing the CO2 emissions, and at the same time, unlike the past, the Coanda nozzle 40, the auxiliary attracting mixing hole 43, Through the configuration of the air supply unit 50, a sufficient amount of high-temperature combustion gas for mixing can be sucked into the combustion chamber 10, and the wall thickness of the combustion chamber 10 and the size of the entire combustion apparatus are significantly reduced. It has the effect of it is. This also applies to the second to fourth embodiments described later.

The second embodiment, as illustrated in FIG.
Although the configuration and configuration are the same as those of the first embodiment described above, the chimney 22 is formed in the upper stage of the discharge part 60 of the combustion chamber 10, and the chimney 22 and the gas flow passage 21 are communicated with each other via the bypass pipe 30. It is a structure to let you.

That is, in the second embodiment, the discharge portion 60 is connected to the combustion chamber 10 but not to the gas flow passage 21, and the gas flow passage 21 formed between the housing 20 and the combustion chamber 10 is used. Is further provided with a bypass pipe 30 that communicates with the discharge section 60 of the combustion chamber 10 (more specifically, the chimney 22 of the discharge section 60).

Further, in the bypass pipe 30 (more specifically, one side of the bypass pipe 30 (a portion where the bypass pipe 30 and the chimney 22 are connected)), the above-described Coanda nozzle 40 is provided inside. As in the embodiment, the outer peripheral edge of the Coanda nozzle 40 provided in the inner pipe is separated from the inner peripheral edge of the bypass pipe 30 without contacting the inner peripheral edge, and the Coanda in the bypass pipe 30 is provided. An auxiliary attracting and mixing hole 43 is formed around the nozzle 40, and an auxiliary air supply unit 70 is further installed on one side of the Coanda nozzle 40.

  Accordingly, the high-temperature combustion gas burned and discharged in the combustion chamber 10 is discharged to the outside through the discharge portion 60 and the chimney 22, and is discharged to the Coanda nozzle 40 installed in the bypass pipe 30 during the discharge. When air is injected or supplied into the bypass pipe 30, the supplied air (primary air) causes the high-temperature combustion gas (primary combustion gas) discharged from the chimney 22 to enter the bypass pipe 30. Inhaled by inhalation. Also, at the moment when the primary air attracts the primary combustion gas and is mixed and discharged, the secondary air is attracted via the auxiliary air supply unit 70 and mixed with the primary mixture classification (mixed gas). However, when discharged into the combustion chamber 10, high-temperature combustion gas (secondary combustion gas) is further attracted and sucked through the auxiliary induction mixing hole 43 and mixed, and discharged into the combustion chamber 10 in the secondary mixing classification. Is Rukoto.

  In contrast, in the second embodiment, air is supplied to the combustion chamber 10 as in the first and third embodiments described later, and at the same time, the high-temperature combustion gas is not mixed. After the air and the high-temperature combustion gas are mixed in advance to form a mixed gas, the mixed gas in the mixed state passes through the gas flow passage 21 and passes through the air injection hole 11 on the outer peripheral edge of the combustion chamber 10. And being supplied to the inside of the combustion chamber 10.

  Also in the second embodiment, a large number of Coanda nozzles 40 can be installed. However, a Coanda nozzle 40 is installed for each bypass pipe 30 that connects the chimney 22 and the gas flow passage 21 to each other, or Of course, a number of Coanda nozzles 40 are installed in the detour pipe 30 in the width direction.

A third embodiment, as illustrated in FIGS. 9 and 10,
By applying the first embodiment in the form of a waste incinerator, as in the first embodiment, the combustion chamber 10 in which the fuel supply unit 12 is formed and the outer peripheral edge of the combustion chamber 10 are spaced apart from each other. And a discharge portion 60 provided in communication with the combustion chamber 10 and the housing 20.

  That is, a combustion gas flow passage is formed in a side portion of the combustion chamber 10, and a high-temperature combustion gas (high-temperature exhaust gas) attracted by an air flow by a large number of Coanda nozzles 40 formed on the side wall of the incinerator. Are injected into the combustion chamber (ex: incinerator) to form MILD combustion.

Explaining this in detail,
When a material to be combusted (or incinerated) is provided via the fuel supply unit 12 formed at one end of the housing 20, the provided combustible material is supplied to the combustion chamber 10 via the ram pusher 23. Is pushed and supplied to the inside of the combustion chamber 10 and burned by a burner 13 or the like installed inside the combustion chamber 10.

  Thereafter, the residue is discharged at the lower stage of the discharge section 60, and the high-temperature combustion gas generated by combustion in the combustion chamber 10 passes through the discharge section 60, and in the gas flow passage 21 formed between the combustion chamber 10 and the housing 20 It will flow.

  In the third embodiment, as in the first embodiment, each of the air injection holes 11 formed with a large number of perforations in the longitudinal direction on the outer peripheral edge of the combustion chamber 10 is provided. By installing the Coanda nozzle 40 so that the auxiliary attracting and mixing hole 43 is formed in the periphery without being in contact with the inner peripheral edge, and further installing the auxiliary air supply unit 70 on one side of the Coanda nozzle 40, Due to the air injected in the combustion chamber 10, the auxiliary air supply unit 70 also attracts and flows air into the Coanda nozzle 40, and the high-temperature combustion gas flowing in the gas flow passage 21 enters the Coanda nozzle 40. The air injected from the combustion chamber 10 is attracted and sucked into the Coanda nozzle 40, and the air and the high-temperature combustion gas are mixed in the Coanda nozzle 40 to form a primary mixing gas. The form of flows into the combustion chamber 10 in the form. Further, a mixed gas (primary mixing classification) in which high-temperature exhaust gas and air are mixed through the Coanda nozzle 40 is discharged, and high-temperature combustion is also performed through the auxiliary induction mixing hole 43 around the Coanda nozzle 40. The gas is further attracted and sucked to be mixed and discharged into the secondary mixed classification (mixed gas in which high-temperature combustion gas is further mixed with the primary mixed gas).

  Further, in the case of the third embodiment, a chimney 22 installed in the housing 20 is formed in the discharge portion 60 as in the second embodiment according to the user's embodiment. After the gas flow passage 21 is changed to a structure further including a bypass pipe 30 that communicates with the chimney 22, a single or a large number of Coanda nozzles 40 are provided in the bypass pipe 30, so that air and high temperature are preliminarily provided. These combustion gases can be mixed and supplied inside the combustion chamber 10.

The fourth embodiment, as illustrated in FIG.
The high-temperature combustion gas generated in the combustion chamber 10 is re-attracted in the combustion chamber 10 by the Coanda nozzle 40 and mixed with air to burn the fuel, so that the Coanda nozzle 40 and the air supply are burned in the form of a burner. In this embodiment, the portion 50 is provided on one side of the gas flow passage 21.

Explaining this in detail,
Only one side of the combustion chamber 10 (ex: burner chamber) that is open at both ends and open inside is opened, but the combustion chamber 10 is separated from the outer peripheral edge so as to surround the combustion chamber 10. A housing 20 that forms a gas flow passage 21 between the chamber 10 and the chamber 10 is provided.

  In such a fourth embodiment, fuel is supplied at one of the parts of the separation between the combustion chamber 10 and the housing 20 through the fuel supply pipe, and the fuel is supplied to the part thus supplied with fuel. A burner 13 is installed. In addition, in the combustion chamber 10, the fuel supplied through the fuel supply unit 12, the air supplied through the gas flow passage 21 described above, the combustion flame through the burner 13, and high-temperature combustion It is to discharge gas.

  On the other hand, in the fourth embodiment, among the gas flow passages 21 formed at the outer peripheral edge of the combustion chamber 10 and the housing 20, the gas flow passage 21 on one side where the combustion flame is generated is locally single or A large number of Coanda nozzles 40 and air supply units 50 are installed.

  The Coanda nozzle 40 is installed in such a manner that the auxiliary attracting and mixing hole 43 is formed on the outer peripheral edge of the Coanda nozzle 40 as in the first, second, and third embodiments. That is, it is provided in the gas flow passage 21 so that the outer peripheral edge of the Coanda nozzle 40 is not in contact with the inner peripheral edge of the gas flow passage 21. An auxiliary air supply unit 70 is further installed on the side.

  In addition, when high-temperature combustion gas is discharged together with the combustion flame in the combustion unit, when the air supply unit 50 supplies air from the inside of the Coanda nozzle 40 toward the fuel supply pipe side, the supplied air assists. Additional air is further attracted and sucked into the Coanda nozzle 40 through the air supply unit 70, and as described above, the high-temperature combustion gas is supplied by the air supplied through the air supply unit 50 and the auxiliary air supply unit 70. Is attracted to the gas flow passage 21, and when air and high-temperature combustion gas are mixed in the gas flow passage 21, they are supplied to the fuel supply unit 12 side in the form of mixed gas. When the gas is supplied, additional high-temperature combustion gas is further sucked and mixed through the auxiliary attracting and mixing hole 43 and discharged.

  In the case of the air supply unit 50 described above, it is a matter of course that a separate air supply device (ex: air compression tank, air pump, air head 52, etc.) for supplying air must be installed. In the case of the fourth embodiment, a spark plug for ignition is further provided.

As described above, the present invention has been described with reference to limited embodiments and drawings. However, the present invention is not limited thereto, and the technical idea of the present invention can be determined by those who have ordinary knowledge in the technical field to which the present invention belongs. It goes without saying that various modifications and changes can be made within the equivalent scope of the claims set forth below.

Claims (11)

A combustion chamber 10 in which a large number of air injection holes 11 are formed at the outer peripheral edge, and a combustion target substance is combusted therein;
A housing 20 that is spaced apart from the outer periphery of the combustion chamber 10 and that forms a gas flow passage 21 between the combustion chamber 10 and the high-temperature combustion gas combusted in the combustion chamber 10;
The auxiliary injection / mixing hole 43 is formed between the air injection hole 11 and the air injection hole 11 so as to be separated from the inner peripheral edge of the air injection hole 11. A Coanda nozzle 40 that attracts hot combustion gases therein so that the hot combustion gases are mixed with air and re-entered in the combustion chamber 10;
An air supply unit 50 for injecting air into the Coanda nozzle 40;
A high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect characterized by comprising: A plurality of air injection holes 11 are formed in the outer peripheral edge, and a combustion chamber 10 in which a combustion target substance is combusted;
A housing 20 spaced apart from the outer periphery of the combustion chamber 10 and forming a gas flow passage 21 between the combustion chamber 10;
A bypass pipe 30 for communicating the gas flow passage 21 and the discharge part 60 of the combustion chamber 10;
An auxiliary induction mixing hole 43 is formed in the bypass pipe 30 so as to be separated from the inner peripheral edge of the bypass pipe 30, and a high-temperature combustion gas is formed by air injected into the bypass pipe 30. A Coanda nozzle 40 that causes the hot combustion gas to be mixed with air and re-entered in the combustion chamber 10;
An air supply unit 50 for injecting air into the Coanda nozzle 40;
A high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect characterized by comprising: A combustion chamber 10 in which a combustion target substance is burned;
A housing 20 that is spaced apart from the outer periphery of the combustion chamber 10 and that forms a gas flow passage 21 between the combustion chamber 10 and the high-temperature combustion gas combusted in the combustion chamber 10;
The gas flow passage 21 is provided in the form separated from the inner peripheral edge of the gas flow passage 21 so that an auxiliary induction mixing hole 43 is formed between the gas flow passage 21 and air injected into the gas flow passage 21. A Coanda nozzle 40 that attracts combustion gas to the inside and allows the mixed gas of the high-temperature combustion gas and air to re-flow into the combustion chamber 10;
An air supply unit 50 for injecting air into the Coanda nozzle 40;
A high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect characterized by comprising: The Coanda nozzle 40 is
4. A fluidized furnace 41 having a gentle slope in the lengthwise direction is formed in the inside, and the fluidized furnace 41 is provided with a projecting portion 42 having a narrow diameter. A high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to any one of the above. The air supply unit 50 includes:
By injecting air from the projecting portion 42 side in the fluidized furnace 41 toward the discharge direction of the mixed gas, the injected air flows along the wall surface of the fluidized furnace 41 and attracts high-temperature combustion gas in the injection direction. The high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to any one of claims 1 to 3, wherein the inhalation is performed. The auxiliary attraction mixing hole 43 is
When the mixed gas is discharged from the Coanda nozzle 40, the high temperature combustion gas is further attracted and mixed through the auxiliary induction mixing hole 43 through the discharge of the mixed gas. A high temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to any one of claims 1 to 3. The air injection hole 11 is
The high temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to any one of claims 1 to 3, wherein a preset angle is formed with an inner wall of the combustion chamber (10). The Coanda nozzle 40 is
3. A plurality of the detour pipes 30 are installed, and air and high-temperature combustion gas are mixed in advance in the detour pipe 30 and then supplied to the combustion chamber 10 in a mixed gas form. High-temperature FGR ultra-low NOx combustion system using the Coanda effect. The air supply unit 50 includes:
The first control valve 51 is installed for each air supply unit 50, and the flow rate and the opening / closing amount of the injected or injected air are individually controlled, so that the high-temperature combustion gas that is induced and sucked by the air The high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to any one of claims 1 to 3, wherein an intake amount of the gas is adjusted. A number of auxiliary units are installed on the Coanda nozzle 40 on the side where the high temperature combustion gas flows, and when the high temperature combustion gas is attracted by the air supply unit 50, the outside air other than the air supply unit 50 is further attracted. An air supply unit 70;
The high temperature FGR ultra low NOx combustion apparatus using the Coanda effect according to any one of claims 1 to 3, further comprising: The multiple auxiliary air supply units 70 include
The second control valve 71 is installed, and the flow rate and opening / closing amount of the injected or injected air are individually controlled, thereby adjusting the intake amount of the high-temperature combustion gas that is inhaled by the air. The high-temperature FGR ultra-low NOx combustion apparatus using the Coanda effect according to claim 10.

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