JP2007155216A - Two-layer type combustor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-layer type combustor of a premixed combustion type suiting one side heating, and capable of sufficiently preheating premixed gas. <P>SOLUTION: The two-layer type combustor 10 has a premix chamber 12 provided with a passage introducing the premixed gas from an exterior to a center part, a combustion chamber 14 provided with a passage exhausting exhaust gas from a center part to an exterior, a heat transfer bulkhead interposed between the premix chamber 12 and the combustion chamber 14, an ignition means 18 provided in a substantially center part for carrying out ignition in a combustion chamber 14 side, and extinction holes 20 arranged in a periphery of the ignition means 18, and communicating the premix chamber 12 with the combustion chamber 14. It is favorable that both passages are spirally formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a two-layer combustor, and more particularly to a two-layer combustor suitable as an alternative to an electric heater.

  Conventionally, electric heaters have been widely used as heating devices for home and business use. Generally, this type of electric heater loses much of the energy of fossil fuel during power generation / transmission, so it is said that the energy utilization efficiency for fossil fuel is about 40%.

  In recent years, further energy saving has been promoted from the viewpoint of suppressing the load on the global environment, and attempts have been actively made to make effective use of energy for heating devices.

  Under such circumstances, a combustor called a micro combustor has been proposed as an alternative to an electric heater. Since this micro combustor can directly use the heat of combustion of fossil fuel, the power generation process that loses about 60% of energy can be omitted. Therefore, it is expected as a technology that can achieve significant energy saving.

  For example, in Non-Patent Document 1 and Patent Document 1, after the premixed gas is fed from the inlet of a spiral tube in which the flow paths of the premixed gas and the exhaust gas are alternately arranged and burned at the center thereof A micro combustor having a structure in which premixed gas is preheated by exhaust heat in the process of releasing high-temperature exhaust gas to the outside is disclosed.

  Moreover, in patent document 2, the combustion part which arrange | positioned the oxidizing gas flow path and the exhaust gas flow path alternately in the shape of a spiral across the heat transfer wall, and the combustion part and the heat transfer plate were arranged in parallel. A micro combustor having a fuel preheating chamber and a supply hole for supplying fuel in the fuel preheating chamber to an oxidizing gas flow path is disclosed.

“Strategic development of energy use rationalization technology Leading research and development of effective energy utilization basic technology R & D of microcombustors for heat sources” 2003-2004 results report Trustee Tohoku University Trustee Ishikawajima-Harima Heavy Industries Co., Ltd., search bar Code number 100005086, [online], New Energy and Industrial Technology Development Organization, results report database, [searched on November 8, 2005], Internet <URL: http: //www.nedo.go. jp / database / index.html> JP-A-2005-76973 JP 2005-76974 A

  However, the conventionally known micro combustors have room for improvement in the following points.

  That is, the micro combustors described in Non-Patent Document 1 and Patent Document 1 have a double-sided heating structure in which the upper and lower surfaces are heated. Therefore, for example, when the micro combustor is applied to a single-sided heating device such as a stove, there is a problem that ineffective heating occurs and heating efficiency is impaired.

  As described in Non-Patent Document 1, when a conventional micro combustor is ignited from room temperature, it requires a continuous spark of about 7.5 minutes from the start of ignition to the start of self-sustained combustion, and it takes time to start up. Take it.

  This is presumably because the time for heat exchange between the premixed gas and the exhaust gas is relatively short, and the preheating of the premixed gas is not yet sufficient.

  On the other hand, the micro combustor described in Patent Document 2 is a diffusion combustion type micro combustor that supplies fuel gas and oxidant gas separately and mixes them by diffusion inside the main body. Therefore, Patent Document 2 does not specifically mention the configuration of the premixed combustion type microcombustor that supplies the premixed gas.

  Even if this technology is applied to a premixed combustion type micro combustor, it is difficult to apply the technology as it is because of the following problems.

  That is, in the micro combustor described in Patent Document 2, the heat generated in the combustion section is transmitted to the fuel preheating chamber provided in parallel with the combustion section.

  However, in general, the volume ratio of fuel to air is approximately 1/10 in terms of an equivalent ratio, so it can be said that the volume of gas (fuel) that receives heat in the fuel preheating chamber is extremely small.

  For this reason, it is considered that heat generated in the combustion section cannot be sufficiently recovered in the fuel preheating chamber, and a considerable amount of heat is released from the lower surface or the like.

  Further, in the micro combustor of Patent Document 2, some fuel is sucked into the combustion part from a hole relatively far from the fuel supply port, and some fuel is sucked into the combustion part from a hole relatively close to the fuel supply port.

  For this reason, it is unlikely that the gas supplied into the fuel preheating chamber can be sufficiently preheated.

  Therefore, the problem to be solved by the present invention is to provide a premixed combustion type two-layer combustor suitable for single-sided heating and capable of sufficiently preheating a premixed gas.

  In order to solve the above problems, a two-layer combustor according to the present invention includes a premixing chamber having a flow path for introducing a premixed gas from the outside to the center, and a flow for exhausting exhaust gas from the center to the outside. A combustion chamber provided with a passage, a heat transfer partition partitioning between the premixing chamber and the combustion chamber, an ignition means which is provided substantially at the center and ignites on the combustion chamber side, and The gist of the invention is to have a flame extinguishing hole that is disposed around and communicates with the premixing chamber and the combustion chamber.

  At this time, the flow path of the premixing chamber and / or the flow path of the combustion chamber may be formed in a spiral shape.

  Moreover, the part of the inner wall surface of the premixing chamber excluding the heat transfer partition and / or the outer wall surface of the premixing chamber may be covered with a ceramic layer.

  Further, it is preferable that a ceramic body is fitted into a heat transfer partition around the ignition means, and the flame extinguishing hole is formed in the ceramic body.

  In addition, a cylindrical body may be provided upright on the periphery of the flame extinguishing hole on the combustion chamber side and / or the premixing chamber side.

  On the other hand, the gist of the stove according to the present invention is that the above-described two-layer combustor according to the present invention is incorporated.

  In the two-layer combustor, the premixed gas blown out from the flame extinguishing hole is ignited by the ignition means at the center of the combustion chamber, and combustion starts.

  The object to be heated can be heated by heat conduction or radiant heat from the surface opposite to the heat transfer partition in the combustion chamber. Moreover, the exhaust gas by combustion is discharged | emitted from the center part outside along the flow path formed in the combustion chamber.

  On the other hand, in the premixing chamber, the heat of the combustion chamber transmitted through the heat transfer partition is recovered, and the premixed gas in the premixing chamber is preheated. Here, the premixed gas is introduced into the central portion from the outside along the flow path formed in the premixing chamber. Therefore, the premixed gas is in contact with the heat from the combustion chamber for a relatively long time until reaching the center. Therefore, the premixed gas is sufficiently preheated before being blown out from the flame extinguishing hole in the center. In the two-layer combustor, since the gas that receives heat from the combustion chamber is a premixed gas, the heat can be effectively recovered.

  Thus, the two-layer combustor is suitable for single-sided heating because the surface on the opposite side of the heat transfer partition in the combustion chamber is the heating surface. Therefore, for example, it can be suitably used for a single-sided heating device such as a stove. On the other hand, the premixed gas can be sufficiently preheated in the premixing chambers arranged in parallel via the heat transfer partition. Therefore, heat exchange efficiency can be improved as compared with the conventional case. Also, the combustibility is improved and the start-up time can be shortened.

  In addition, since the flame extinguishing holes are arranged around the ignition means, the dispersibility of the premixed gas in the combustion chamber is also improved. Further, even when the premixed gas is preheated to a high temperature, the premixing chamber and the combustion chamber are communicated with each other through the flame extinguishing hole, so that it is possible to prevent a backfire phenomenon that the flame enters the premixing chamber side. .

  At this time, when the flow path of the premixing chamber is formed in a spiral shape, the time during which the heat from the combustion chamber is in contact with the premixed gas can be lengthened. Therefore, there is an advantage that it becomes easier to preheat the premixed gas. On the other hand, when the flow path of the combustion chamber is formed in a spiral shape, it is possible to lengthen the time during which exhaust gas having heat is discharged. Therefore, there is an advantage that the heat of the exhaust gas can be more easily transmitted to the premixing chamber side.

  In the above two-layer combustor, when the inner wall of the premixing chamber except the heat transfer partition and / or the outer wall surface of the premixing chamber is covered with a ceramic layer, Since the heat insulation performance in the mixing chamber is improved, the heat transmitted to the premixing chamber is hardly released to the outside. Therefore, it is more suitable for single-sided heating, and the heat exchange efficiency can be further improved.

  Further, in the above two-layer combustor, when a ceramic body is fitted into the heat transfer partition around the ignition means, and the above-mentioned flame extinguishing hole is formed in the ceramic body, the heat resistance around the flame extinguishing hole is improved.

  Therefore, due to the high heat in the combustion chamber, relatively small flame extinguishing holes are not easily oxidized or deformed, and durability is improved.

  Further, in the above-described two-layer combustor, when a cylindrical body is erected on the periphery of the flame extinguishing hole on the combustion chamber side and / or the premixing chamber side, the extinguishing diameter of the extinguishing hole can be increased. Therefore, there is an advantage that the pressure loss at the time of blowing the premixed gas can be reduced.

  On the other hand, the stove is excellent in heating efficiency and the like because the two-layer combustor is incorporated therein.

  Hereinafter, a two-layer combustor according to an embodiment (hereinafter, also referred to as “the present two-layer combustor”) will be described. Here, the case where both flow paths of the premixing chamber and the combustion chamber are formed in a spiral shape is shown as an example of a preferred embodiment.

  FIG. 1 is a perspective view schematically showing the appearance of the present two-layer combustor. FIG. 2 is a front view of the two-layer combustor. 3 is a cross-sectional view taken along the line AA in FIG. 4 is a cross-sectional view taken along the line BB in FIG. 5 is a cross-sectional view taken along the line CC in FIG.

  The present two-layer combustor 10 can be a small combustor having an outer shape of, for example, several tens of centimeters to several centimeters, and is formed in a sealed structure mainly from a metal material such as stainless steel. As shown in FIGS. 1 to 5, the two-layer combustor 10 includes a premixing chamber 12, a combustion chamber 14, a heat transfer partition 16, an ignition means 18, and a flame extinguishing hole 20 as its basic configuration. Have. Hereinafter, these configurations will be described in detail.

  The premixing chamber 12 is formed in a substantially cylindrical shape, and has a sealed space surrounded by the bottom plate 22, the outer peripheral wall 24, and the heat transfer partition 16. A premixed gas inlet 26 for introducing the premixed gas F from the tangential direction is provided on the outer peripheral wall 24 of the premixed chamber 12.

  Inside the premixing chamber 12, a spiral flow path 28 is formed as a passage for the premixed gas F. The spiral flow path 28 is formed by a space surrounded by the spiral wall 30 or the outer peripheral wall 24, the bottom plate 22, and the heat transfer partition 16.

  With the above configuration, the mixing ratio and flow rate of the fuel and the oxidant gas (air, oxygen, etc.) are adjusted, and the premixed gas F introduced from the premixed gas introduction port 26 passes along the spiral flow path 28. Guided from outside to the center of the vortex. In addition, the kind of fuel is not specifically limited, Various combustible fuels, such as city gas, methane, and propane, can be used.

  On the other hand, the combustion chamber 14 is formed in a substantially cylindrical shape, similar to the premixing chamber 12, and has a sealed space surrounded by the top plate 32, the outer peripheral wall 34, and the heat transfer partition 16. Yes. The outer peripheral wall 34 of the combustion chamber 14 is provided with an exhaust gas discharge port 36 for discharging the exhaust gas E in the tangential direction.

  Inside the combustion chamber 14, a spiral channel 38 that is a passage for the exhaust gas E is formed. The spiral flow path 38 is formed by a space surrounded by the spiral wall 40 or the outer peripheral wall 34, the top plate 32, and the heat transfer partition 16.

  With the above configuration, the exhaust gas E generated by the combustion is discharged outside from the vortex center along the spiral channel 38.

  In addition, the spiral walls 30 and 40 in the premixing chamber 12 and the combustion chamber 14 are preferably made of a material having excellent heat conductivity, and the plate thickness is preferably set as thin as possible. Further, the intervals between the spiral walls 30 and 40 in the premixing chamber 12 and the combustion chamber 14 may be the same or different from each other.

  Here, in the present two-layer combustor 10, one side of the premixing chamber 12 and one side of the combustion chamber 14 are in contact via a heat transfer partition 16. That is, the micro combustors described in Non-Patent Document 1 and Patent Document 1 have a single-layer structure, whereas the two-layer combustor 10 has a heat transfer partition 16 on one side of the premixing chamber 12. It has a two-layer structure in which combustion chambers 14 are arranged in parallel. At this time, the premixing chamber 12 and the combustion chamber 14 are disposed so that the central portions of the spiral flow paths 28 and 38 substantially coincide.

  In the two-layer combustor 10, the heat transfer partition 16 transmits heat generated in the combustion chamber 14 to the premixing chamber 12 side, and serves to partition the premixing chamber 12 and the combustion chamber 14. is doing.

  In the present two-layer combustor 10, an ignition means 18 is provided at substantially the center of both spiral flow paths 28 and 38.

  Specific examples of the ignition means 18 include an igniter and a ceramic heater, but are not particularly limited.

  At this time, the ignition means 18 is arranged so that the ignition point 42 is on the combustion chamber 14 side. 1 to 5 exemplify a case where the ignition means 18 is inserted from the premixing chamber 12 side toward the combustion chamber 14 side and the ignition point 42 is disposed in the combustion chamber 14.

  In the two-layer combustor 10, a plurality of flame extinguishing holes 20 are arranged around the ignition means 18. The flame extinguishing hole 20 communicates the premixing chamber 12 and the combustion chamber 14 and has a role of allowing the premixed gas F introduced into the premixing chamber 12 to flow into the combustion chamber 14.

  Specifically, the flame extinguishing hole 20 is formed in the heat transfer partition 16 between the spiral wall 40 positioned around the center of the vortex and the ignition means 18. Therefore, in the present two-layer combustor 10, the space surrounded by the vortex wall 40 at the center of the vortex becomes the combustion space.

  In FIG. 3, for example, a case where 40 flame extinguishing holes 20 are arranged in a staggered manner so as to surround the ignition means 18 is illustrated. Further, the number of the flame extinguishing holes 20 is not particularly limited, and can be variously adjusted according to the type of fuel used.

  Here, in the present two-layer combustor 10, the flame extinguishing hole 20 means a hole having a diameter equal to or smaller than the extinguishing diameter. If the diameter of the hole communicating with the premixing chamber 12 and the combustion chamber 14 is equal to or less than the extinguishing diameter, it is possible to prevent the flame generated in the combustion chamber 14 from backfired to the premixing chamber 12 side.

  The specific flame extinguishing diameter can be determined in consideration of the type of fuel, the blowing speed of the premixed gas, the assumed temperature of the premixed gas, and the like.

  Next, the effect of the present two-layer combustor having the above-described configuration will be described.

  In the two-layer combustor 10, when the premixed gas F blown from the flame extinguishing hole 20 is ignited by the ignition means 18 in the center of the combustion chamber 12, flame is formed and combustion starts.

  Once the flame is formed, it begins to heat up from the center and eventually reaches a steady state at a constant temperature. Then, an object to be heated (not shown) can be heated by heat conduction or radiant heat from the top plate 32 of the combustion chamber 14.

  Further, the exhaust gas E due to combustion flows from the central portion toward the outside along the spiral flow path 38 formed in the combustion chamber 14, and is discharged from the exhaust gas discharge port 36.

  On the other hand, in the premixing chamber 12, the heat of the combustion chamber 14 transmitted through the heat transfer partition 16 is recovered, and the premixed gas F in the premixing chamber 12 is preheated. Here, the premixed gas F introduced from the premixed gas introduction port 26 is introduced into the central portion from the outside along the spiral flow path 28.

  Therefore, the premixed gas F is relatively preheated before being blown out from the flame extinguishing hole 20 because the premixed gas F is in contact with the heat from the combustion chamber 14 for a relatively long time. Further, in the present two-layer combustor 10, since the gas that receives heat from the combustion chamber 14 is the premixed gas F, heat is effectively recovered compared to the case where the gas that receives heat is a single fuel. be able to.

  Thus, the two-layer combustor 10 is suitable for single-sided heating because the top plate 32 in the combustion chamber 14 serves as a heating surface. Therefore, for example, it can be suitably used for a single-sided heating device such as a stove. In addition, the premixed gas F is sufficiently preheated in the premixing chamber 12 arranged in parallel via the heat transfer partition 16. Therefore, compared with the conventional case, heat exchange efficiency can be improved, and start-up time can be shortened by improving combustibility.

  Further, since the flame extinguishing holes 20 are disposed around the ignition means 18, the dispersibility of the premixed gas F into the combustion chamber 14 is also improved. In the present two-layer combustor 10, since the flame extinguishing holes 20 are arranged in a staggered manner, it is easy to disperse the premixed gas F and improve the combustibility.

  Even if the premixed gas F is preheated to a high temperature, the premixing chamber 12 and the combustion chamber 14 communicate with each other through the flame extinguishing hole 20, so that the flame enters the premixing chamber 12 side. Can prevent fire phenomenon.

  Thus, the present two-layer combustor 10 is suitable for single-sided heating, and can sufficiently preheat the premixed gas F. Therefore, for example, if one or more of them are incorporated into a single-sided heating device such as a stove as required, a stove having excellent heating efficiency and the like can be obtained.

  Although the two-layer combustor according to the embodiment has been described above, the above embodiment is not intended to limit the present invention, and various modifications and improvements can be made.

  For example, in the above-described embodiment, the case where the heat transfer partition wall 16 is interposed between the premixing chamber 12 and the combustion chamber 14 has been described, but the present invention is not limited to this.

  The heat transfer partition 16 can be substituted by, for example, a top plate provided in the premixing chamber 12 and / or a bottom plate provided in the combustion chamber 14.

  For example, in the above-described embodiment, the case where the top plate 32 of the combustion chamber 14 is configured as a part of the two-layer combustor 10 has been described, but the present invention is not limited to this.

  The top plate 32 of the combustion chamber 14 can be replaced by, for example, the object to be heated itself or a part of the container (pan bottom, iron plate, etc.) in which it is placed if the inside of the combustion chamber 14 can be made airtight. .

  In addition, for example, as shown in FIGS. 6 and 7, the two-layer combustor 10 includes a portion of the inner wall surface of the premixing chamber 12 excluding the heat transfer partition 16 or an outer wall surface of the premixing chamber 12 ( The outer peripheral wall 24 and the bottom plate 22), or both wall surfaces thereof may be covered with the ceramic layer 44.

  Specific examples of the material of the ceramic layer 44 include cordierite and silicon carbide.

  In such a configuration, the heat insulation performance in the premixing chamber 12 is improved, so that the heat transmitted to the premixing chamber 12 is hardly released to the outside. Therefore, it is more suitable for single-sided heating, and the heat exchange efficiency can be further improved.

  Moreover, in the said embodiment, although illustrated about the case where the flame-extinguishing hole 20 was formed in the metal heat-transfer partition 16, other than this, a ceramic body (not shown) is provided in the heat-transfer partition 16 around the ignition means 18 at least. The flame-extinguishing hole 20 may be formed in the ceramic body.

  In the case of such a configuration, the heat resistance around the flame extinguishing hole 20 is improved. Therefore, the relatively small flame extinguishing hole 20 is not easily oxidized or deformed by the high heat in the combustion chamber 14, and compared with the case where the flame extinguishing hole 20 is formed in the metal heat transfer partition 16. And there are advantages such as improved durability.

  Further, for example, in the two-layer combustor 10, as shown in FIG. 8, a cylindrical body 46 may be erected on the periphery of the flame extinguishing hole 20 on the combustion chamber 14 side. Further, a cylindrical body (not shown) may be erected on the periphery of the flame extinguishing hole 20 on the premixing chamber 12 side.

  In such a configuration, heat is absorbed by the cylindrical body 46 and it becomes difficult to maintain the amount of heat necessary for combustion, so that the extinguishing diameter of the extinguishing hole 20 can be formed large. Therefore, it is possible to reduce the pressure loss when the premixed gas F is blown out.

  In the above embodiment, the case where the flow path of the premixing chamber and the flow path of the combustion chamber of the two-layer combustor according to the present invention are both formed in a circular spiral shape has been described. Alternatively, a polygonal spiral shape such as a quadrangular shape or a hexagonal shape may be used.

  In the above embodiment, the spiral flow path 28 of the premixed gas F and the spiral flow path 38 of the exhaust gas E are illustrated as being formed in a spiral shape in the same direction. It may be formed in a spiral shape.

  Moreover, in the said embodiment, although illustrated about the case where the flow path of the premixing chamber which the two-layered combustor which concerns on this invention has, and the flow path of the combustion chamber were formed in the shape of a spiral, in addition to that, these flow paths Either one or both of them may be formed radially.

  Further, in the above embodiment, the premixed gas F introduced from the premixed gas inlet 26 is guided from the outside to the vortex center through one spiral channel 28. The premixed gas introduced from the mixed gas introduction port may be guided from the outside to the center through a plurality of rows of flow paths.

  Similarly, in the above embodiment, the exhaust gas E exhausted from the exhaust gas exhaust port 36 is guided from the center of the vortex to the outside through one spiral channel 28. The exhaust gas discharged from the discharge port 36 may be guided from the central portion to the outside through a plurality of rows of flow paths.

  Hereinafter, a two-layer combustor according to the present invention will be described with reference to examples.

  First, a two-layer combustor having the shape shown in FIGS. 1 to 5 was manufactured using stainless steel (SUS430). At this time, the diameter of the two-layer combustor is about 120 mm, the thickness of both spiral walls is 2 mm, the width of both flow paths is 4 mm, the diameter of the combustion space surrounded by the spiral wall at the center of the vortex is about 23 mm, and the diameter of the quenching hole Was 0.8 mm. An igniter was used as the ignition means, and 13A was used as the fuel gas.

  Next, an outline of the combustion test apparatus for the two-layer combustor produced will be described. That is, as shown in FIG. 9, the produced two-layer combustor 10 is covered with a ceramic fiber heat insulating material 50, and a premixed gas introduction pipe 52 (made of polytetrafluoroethylene) is connected to the premixed gas introduction port 26. At the same time, an exhaust gas discharge pipe 54 (made of polytetrafluoroethylene) was connected to the exhaust gas discharge port 36.

  In the present embodiment, the fuel (maximum 20 L / min) and air (maximum 200 L / min) supplied from the fuel source 56 and the air source 58 are adjusted by the flow meters 60 and 62 and have a predetermined air ratio. The mixed gas F is used. The premixed gas F is regulated by the pressure gauge 64 and supplied to the premixed gas inlet 26 with a predetermined input amount.

  Next, in order to confirm the combustion state, as shown in FIG. 10, a total of five K-type thermocouples 66 (thermocouple interval 25 mm) are sandwiched between the center portion and both sides of the top plate 32 of the two-layer combustor 10. The surface temperature at the measurement positions 1 to 5 can be measured.

  Next, a combustion test was performed according to the following procedure. That is, first, the flow rates of fuel and air are set by each flow meter. Then, the igniter discharge of the two-layer combustor is started, and immediately after that, the gas and air flow meter valves are opened. As a result, a premixed gas having a predetermined air ratio is supplied to the two-layer combustor with a predetermined input amount. When ignition and combustion start in the combustion chamber, the surface temperature of the top plate rises.

  By the above combustion test, the surface temperature characteristics about 5 minutes after the start of ignition and the temperature rise characteristics about 5 minutes after the start of ignition were determined for the produced two-layer combustor. The exhaust gas temperature was also measured. The input amount of the premixed gas was 2 Kw, 3 Kw, 4 Kw, and 5 Kw. Further, the air ratio was varied between about 1 and 1.3 for each input amount.

  11 to 14 show the relationship between each measurement position and the surface temperature for each input amount. FIG. 15 shows the relationship (temperature rise characteristic) between the elapsed time from the start of ignition and the surface temperature at each measurement position when the input amount is 3 Kw and the air ratio is 1.21.

  According to FIGS. 11 to 14, the surface temperature curve is an upwardly convex curve for any input amount. And it turns out that the surface temperature of the measurement position 3, ie, the center part vicinity is high, and the surface temperature becomes low as it leaves | separates from a center part. Moreover, it turns out that the temperature of center part is 500 degreeC or more (about 5 minutes from the start of combustion) on the conditions of practical air ratio about 1.1.

  Moreover, according to FIG. 15, it turns out that ignition and combustion have arisen in the elapsed time of 0 second vicinity, and starting time is shorter than before. This seems to be because the present two-layer combustor can sufficiently preheat the premixed gas, so that the combustibility is improved.

  From the above results, according to the present invention, it was confirmed that a premixed combustion type two-layer combustor that is suitable for single-sided heating and can sufficiently preheat the premixed gas can be obtained.

It is the perspective view which showed typically the external appearance of the two-layered combustor which concerns on this embodiment. It is a front view of the 2 layer type combustor concerning this embodiment. It is AA sectional drawing in FIG. It is BB sectional drawing in FIG. It is CC sectional drawing in FIG. It is sectional drawing which showed typically an example of the state which provided the ceramic layer in the inner wall face of the premixing chamber. It is sectional drawing which showed typically an example of the state which provided the ceramic layer in the outer wall surface of the premixing chamber. It is sectional drawing which showed typically an example of the state which stood the cylindrical body in the flame-extinguishing hole periphery by the side of a combustion chamber. It is the figure which showed the outline of the combustion test apparatus of a two-layer type combustor typically. It is the figure which showed typically the measurement position of surface temperature. It is the figure which showed the relationship between each measurement position and surface temperature in input amount 2Kw. It is the figure which showed the relationship between each measurement position and surface temperature in input amount 3Kw. It is the figure which showed the relationship between each measurement position and surface temperature in input amount 4Kw. It is the figure which showed the relationship between each measurement position and surface temperature in input amount 5Kw. It is the figure which showed the relationship (temperature rising characteristic) of the elapsed time from the ignition start and the surface temperature of each measurement position in input amount 3Kw and air ratio 1.21.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Two-layered combustor 12 Premixing chamber 14 Combustion chamber 16 Heat transfer partition 18 Ignition means 20 Flame extinguishing hole 22 Bottom plate 24 Outer peripheral wall (premixing chamber side)
26 Premixed gas inlet 28 Spiral channel (premixing chamber side)
30 Spiral wall (premixing chamber side)
32 Top plate 34 Outer wall (combustion chamber side)
36 Exhaust gas outlet 38 Spiral channel (combustion chamber side)
40 Spiral wall (combustion chamber side)
42 Ignition point 44 Ceramic layer 46 Cylindrical body F Premixed gas E Exhaust gas

Claims (6)

A premixing chamber having a flow path for introducing premixed gas from the outside into the center;
A combustion chamber having a flow path for discharging exhaust gas from the center to the outside;
A heat transfer partition partitioning the premixing chamber and the combustion chamber;
Ignition means provided substantially in the center and igniting on the combustion chamber side;
A two-layer combustor, which is disposed around the ignition means and has a flame extinguishing hole communicating the premixing chamber and the combustion chamber.   2. The two-layer combustor according to claim 1, wherein the flow path of the premixing chamber and / or the flow path of the combustion chamber is formed in a spiral shape.   The portion of the inner wall surface of the premixing chamber excluding the heat transfer partition and / or the outer wall surface of the premixing chamber is covered with a ceramic layer. The two-layer combustor as described.   4. The two-layer combustor according to claim 1, wherein a ceramic body is fitted into a heat transfer partition around the ignition means, and the flame extinguishing hole is formed in the ceramic body.   The two-layer combustor according to any one of claims 1 to 4, wherein a cylindrical body is erected on the periphery of the flame extinguishing hole on the combustion chamber side and / or on the premixing chamber side.   A stove in which the two-layer combustor according to any one of claims 1 to 5 is incorporated.

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