JP2009216301A - Burner for reforming fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a burner for reforming fuel can perform stable combustion by finely cutting liquid fuel from a nozzle for spraying fuel. <P>SOLUTION: This burner for reforming fuel by supplying heat for reforming reaction to a reformer, includes a heater 2, and applies a premixing method for vaporizing the liquid fuel and premixing the same with the primary air. The burner is provided with a vaporizing chamber 6 receiving the primary air, and the spray of liquid fuel from the nozzle 4 for spraying fuel, and producing the premixed air-fuel mixture including a vaporized gas, a vaporizing/mixing chamber 7 for promoting vaporization and mixing of the premixed air-fuel from the vaporizing chamber 6, and a jetting section 8 communicating the vaporizing chamber 6 with the vaporizing/mixing chamber 7, and jetting the premixed air-fuel toward an inner sidewall of the vaporizing/mixing chamber 7. An orifice section 15 is disposed at an inflow port of the vaporizing chamber 6, and a distal end section 13 of the nozzle 4 is disposed near the orifice section 15, thus the liquid fuel sprayed from the nozzle 4 can be finely cut, vaporization of the liquid fuel is promoted, and the combustion can be stably performed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel reforming burner used in a fuel cell system or the like.

Conventionally, in this type of fuel reforming burner, liquid fuel and combustion air are vaporized by colliding with a vaporization wall in the vaporization chamber, and then supplied to the burner part while mixing through the gas mixture passage. It was to burn completely. (For example, refer to Patent Document 1.)
JP 2005-180812 A

  By the way, in this conventional apparatus, if the inner diameter of the nozzle for spraying the liquid fuel is small, the liquid fuel can be finely miniaturized, but the pressure loss in the flow path of the liquid fuel becomes large, and the apparatus side for supplying the liquid fuel Has a problem that it is necessary to select one having a large capacity, resulting in high costs. On the contrary, if the inner diameter of the nozzle is large, the liquid fuel sprayed from the nozzle is not finely refined, and stable combustion cannot be obtained.

  The present invention solves the above-described conventional problems, and even when the inner diameter of a nozzle for spraying liquid fuel is large, the fuel reforming can be performed finely and the stable combustion can be obtained. The purpose is to provide a burner.

  In order to solve the above-mentioned problems, the present invention is particularly configured in claim 1 in a fuel reforming burner for supplying heat for reforming reaction to a reformer. The burner is provided with a heater and vaporizes liquid fuel. A premixing system for premixing with primary air, and generating a premixed gas containing vaporized gas upon receiving the primary air and liquid fuel spray from a fuel spray nozzle; A vaporization and mixing chamber that promotes vaporization and mixing of the premixed gas, and the vaporized chamber and the vaporized and mixed chamber communicate with each other, and the premixed gas generated in the vaporized chamber is ejected toward the inner wall of the vaporized and mixed chamber. An ejection part is provided, an orifice part is provided at the inlet of the vaporization chamber, and a tip part of the nozzle is disposed in the vicinity of the orifice part.

  According to a second aspect of the present invention, the orifice portion includes a throttle portion that is tapered toward the vaporization chamber side, and a communication portion that communicates the throttle portion with the vaporization chamber. It shall be arrange | positioned at the said aperture_diaphragm | restriction part.

  According to a third aspect of the present invention, the tip of the nozzle is cut at an acute angle from the front and back to the tip, and windbreak walls are formed on both sides, and the windbreak is cut at an acute angle toward the tip. In addition, the nozzle is arranged so that the axial direction of the ejection portion and the linear direction formed by connecting the tips of the windbreak walls substantially coincide.

  According to the first aspect of the present invention, the orifice portion is provided at the inlet of the vaporizing chamber, and the tip portion of the nozzle is disposed in the vicinity of the orifice portion, so that the liquid fuel sprayed from the nozzle is finely refined. Therefore, vaporization of the liquid fuel is promoted, and stable combustion can be obtained.

  According to the second aspect of the present invention, the orifice part is composed of a throttle part and a communication part that are tapered toward the vaporization chamber side, and the tip part of the nozzle is arranged in the throttle part, thereby combusting primary air. Can be smoothly flown to the vaporizing chamber without being obstructed by the tip of the nozzle and without increasing the pressure loss of the path through which the primary air flows, and the liquid fuel sprayed from the nozzle can be finely atomized. And stable combustion can be obtained.

  According to the third aspect of the present invention, since the tip of the nozzle is cut at an acute angle toward the tip of the nozzle, there is no wraparound of the combustion air to the tip of the nozzle, and the combustion air is not burned even during small thermal power combustion. As the burner can be used in fuel cells, it can be ejected vigorously along the tip of the nozzle cut at an acute angle and burns well without pulsating combustion even during small thermal combustion. Is extremely easy to use. Furthermore, by arranging the nozzle so that the axial direction of the jet part and the line direction formed by connecting the tips of the windbreak walls substantially coincide with each other, the blowing force of the primary air toward the jet part directly acts on the liquid fuel. The liquid fuel is not sent to the vaporization chamber as oil droplets having a large particle size, but the vaporization of the liquid fuel is promoted and stable combustion can be obtained.

Next, an embodiment of the fuel reforming burner of the present invention will be described with reference to the drawings.
Reference numeral 1 denotes a bottomed cylindrical aluminum die-cast vaporizer with a U-shaped heater 2 embedded therein, which is attached downward to an upper portion of a cylindrical body 3 containing a reformer (not shown). In the side wall of the carburetor 1, a small volume of vaporization in which a nozzle 4 for fuel spraying and a primary air supply passage 5 for combustion communicate with the upper part in the upper side near the heater 2. A premixed gas containing vaporized gas is generated by receiving the primary air and the spray of liquid fuel from the fuel spray nozzle 4 in the vaporizing chamber 6, and the premixed gas from the vaporizing chamber 6 is generated. A large-volume vaporizing and mixing chamber 7 that promotes vaporization and mixing is provided on the side of the vaporizing chamber 6, and the vaporizing chamber 6 and the vaporizing and mixing chamber 7 are communicated with each other through an ejection portion 8.

  Further, the ejection portion 8 is formed in a substantially perpendicular direction toward the inner wall of the vaporizing and mixing chamber 7, and the vaporized gas vaporized in the vaporizing chamber 6 and the liquid fuel that has not been vaporized in the vaporizing and mixing chamber 7 together with the primary air. Ejected toward the inner wall, where vaporization is promoted once again, and completely vaporized gas and primary air are mixed in this vaporization mixing chamber 7, and this mixed gas is two-stage flame at the lower end of the vaporization mixing chamber 7. It burns in the 1st flame hole part 10 in which the hole 9 was formed, and the auxiliary | assistant combustion part 11 combusted at the time of starting or lack of heat quantity with this vaporizer 1 and the 1st flame hole part 10 comprises.

  The fuel spray nozzle 4 is formed by narrowing the distal end side of an oil feeding pipe 12 made of a stainless steel pipe having an outer diameter of 3.2 mm so as to have an inner diameter of 0.7 mm. 13 is cut at an acute angle of 30 degrees from the front and the back toward the tip, and a triangular windbreak wall 14 is formed on both sides, and the tip of the windbreak wall 14 is further inclined at an angle of 30 degrees toward the tip of the nozzle 4. In order to prevent the combustion air from flowing into the tip portion 13 of the nozzle 4 at the time of small thermal combustion, the generation of oil droplets is prevented, and the pulsation combustion is prevented to widen the combustion width. It can be done.

  The inlet of the vaporizing chamber 6 is provided with an orifice portion 15 for narrowing a flow path through which the primary air from the primary air supply path 5 and the liquid fuel sprayed from the nozzle 4 pass. The throttle portion 16 is tapered toward the chamber 6 side, and a communication portion 17 that communicates the throttle portion 16 with the vaporizing chamber 6. The tip end portion 13 of the nozzle 4 is disposed in the vicinity of the orifice portion 15. ing. Here, the tip part 13 of the nozzle 4 is arranged in the throttle part 16 that forms the orifice part 15, so that the primary air for combustion from the primary air supply path 5 is obstructed by the tip part 13 of the nozzle 4. And smoothly sent to the vaporizing chamber 6 without increasing the pressure loss of the path through which the primary air flows, and the fineness of the liquid fuel sprayed from the nozzle 4 is good even when the inner diameter of the nozzle 4 is large And stable combustion can be obtained.

  Further, as shown in FIG. 6, the tip portion 13 of the fuel spray nozzle 4 is arranged so that the axial direction A of the ejection portion 8 and the line direction B formed by connecting the tips of the windbreak walls 14 substantially coincide. Is arranged. Here, as shown in FIG. 7, when the nozzle 4 is arranged so that the axial direction A of the ejection portion 8 and the linear direction B formed by connecting the tips of the windbreak walls 14 are substantially orthogonal, the flow flows toward the ejection portion 8. The primary air to be applied directly acts on the liquid fuel from the large open cut surface of the tip end portion 13 of the nozzle 4 as shown in the front view of FIG. 5, and the liquid fuel remains as an oil droplet having a large particle diameter. Therefore, a red flame is generated due to excessive fuel with respect to the primary air, and stable combustion cannot be obtained. However, since the nozzle 4 is arranged as shown in FIG. 6 described above, the air blowing force of the primary air toward the ejection portion 8 is suppressed by the windbreak wall 14 and acts directly on the liquid fuel so that the liquid fuel has a particle size. The fine liquid fuel is sent to the vaporizing chamber 6 without being sent to the vaporizing chamber 6 in the form of large oil droplets, whereby vaporization is promoted and stable combustion can be obtained.

  Reference numeral 18 denotes an off-gas combustion section that burns a reformed gas from the reformer at the start-up and a combustible off-gas containing hydrogen discharged from a fuel cell stack (not shown) at the time of power generation. An off-gas supply pipe 19 penetrating through a side wall facing the first gas passage, and an off-gas flame hole 20 formed on an inclined surface substantially extending from the inclined surface of the first flame hole portion 10 in communication with the off-gas supply pipe 19. The two flame holes 21 are configured.

  Reference numeral 22 denotes a secondary air supply passage formed through the other wall of the carburetor 1, and the secondary air flowing in from the outer periphery of the carburetor 1 is guided by the guide plate 23 to the first flame hole portion 10 and the first air supply passage 22. 2 It guides to the flame hole part 21 and carries out secondary combustion.

  Reference numeral 24 denotes a temperature sensor that is attached to the bottom of the carburetor 1 and detects the temperature of the carburetor 1, and 25 is an ignition electrode that is attached to a position facing the secondary air supply path 22.

Next, the operation of this embodiment will be described.
At the start of the fuel cell system, when the temperature sensor 24 detects that the heater 2 is energized and the vaporizer 1 is heated and reaches a predetermined temperature suitable for vaporization of the liquid fuel, the liquid fuel from the nozzle 4 is detected. The primary air supplied from the primary air supply path 5 is sprayed into the vaporizing chamber 6 together.

  At this time, it is cut at an acute angle of 30 degrees from the front and the back toward the tip, and a triangular windbreak wall 14 is formed on both sides, and the tip of the windbreak wall 14 is further moved to the tip of the nozzle 4 by 30 degrees. By arranging the tip portion 13 of the nozzle 4 having a shape cut at an acute angle in the throttle portion 16 forming the orifice portion 15, the angle of the cut surface of the tip portion 13 of the nozzle 4 and the inclined surface of the throttle portion 16. The primary air for combustion from the primary air supply passage 5 is not obstructed by the tip 13 of the nozzle 4 and does not increase the pressure loss in the path through which the primary air flows. While being smoothly sent to the vaporization chamber 6 side, the liquid fuel sprayed from the nozzle 4 can be finely refined.

  Furthermore, as shown in FIG. 6, the nozzle 4 is arranged so that the axial direction A of the ejection portion 8 and the linear direction B formed by connecting the tips of the windbreak walls 14 substantially coincide with each other. The blowing force of the primary air that is directed to the air acts directly on the liquid fuel from the cut surface of the tip end portion 13 of the nozzle 4 as shown in the front view of FIG. 5 so that the liquid fuel is vaporized as oil droplets having a large particle diameter. Without being sent to the chamber 6, the refined liquid fuel is sent to the vaporizing chamber 6 to promote vaporization.

  Here, the primary air and the liquid fuel that have reached the vaporization chamber 6 are partly vaporized gas, but some of the primary fuel and the vaporized gas are not vaporized and remain as liquid fuel. In the mixed state, it is ejected from the ejection part 8 toward the inner wall of the vaporization mixing chamber 7.

  Further, the liquid fuel that is not sufficiently vaporized in the vaporizing chamber 6 is partially vaporized with the primary air from the primary air supply path 5 to generate a gas whose volume is increased, and the ejection wall 8 to the inner wall of the vaporized mixing chamber 7. The liquid fuel is jetted toward the gas and vaporized while diffusing by colliding with the inner wall. Finally, all of the supplied liquid fuel becomes vaporized gas, and the first flame is well mixed with the primary air in the vaporized mixing chamber 7. After flowing to the hole 10, ejected from the flame hole 9 and ignited by the ignition electrode 25, the secondary air is also supplied from the secondary air supply path 22, and the auxiliary combustion unit 11 first starts combustion. The combustion heat of the auxiliary combustion unit 11 is all supplied to the reformer as heat for reforming.

  Therefore, the liquid fuel can be vaporized surely by making the liquid fuel vaporized in two places, and the liquid fuel can be surely vaporized, clearing the dimensional and shape restrictions as a burner and preventing vaporization defects. Therefore, stable combustion can be always obtained.

  Further, since the ejection portion 8 is formed in a substantially right angle direction toward the inner wall of the vaporization mixing chamber 7, there is no resistance, the ejection is smooth, the ejection power does not decrease, and a better liquid. Fuel vaporization can be obtained.

  Next, the reformed gas from the reformer at the start of the fuel cell system or the combustible off gas containing hydrogen discharged from the fuel cell stack at the time of power generation is supplied from the off gas supply pipe 19 to the second flame hole portion 21. The off-gas combustion unit 18 starts diffusion combustion with the secondary air ignited by the flame of the auxiliary combustion unit 11 and supplied as combustion air by being ejected from the off-gas flame hole 20. Since the flame holes 20 of the two flame holes 21 are also formed on the inclined surface on the extension line of the first flame hole 10, the combustion of off-gas is concentrated at the center as well as the prevention of lift combustion, and the auxiliary combustion part 11. During combustion, reliable ignition can be performed without using the ignition electrode 25.

  When the off-gas combustion unit 18 starts to burn, the amount of heat supplied to the reformer increases, and the reforming catalyst (not shown) reaches a predetermined temperature to temporarily stop the combustion of the auxiliary combustion unit 11. In addition, when the amount of power used increases and the amount of off-gas decreases and the temperature of the reforming catalyst decreases, the auxiliary combustion section 11 is burned again. The combustion of the combustion part 11 is controlled.

  At the time of start-up, the heater 2 is energized to heat the vaporizer 1, but if combustion is started, a part of this combustion heat is heated back to heat the vaporizer 1, so that the heater is heated. The energization to 2 is stopped.

1 is a cross-sectional view of a fuel reforming burner according to the present invention on the primary air supply path side and off-gas supply pipe side. Sectional drawing by the side of the secondary air supply path. FIG. Bottom view The front and side view of the nozzle. Explanatory drawing of a good arrangement example of the nozzle. Explanatory drawing of a bad arrangement example of the nozzle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vaporizer 2 Heater 4 Nozzle 6 Vaporization chamber 7 Vaporization mixing chamber 8 Ejection part 13 Nozzle tip part 14 Windbreak wall 15 Orifice part 16 Restriction part 17 Communication part

Claims (3)

  In a fuel reforming burner for supplying heat for reforming reaction to a reformer, the burner is equipped with a heater and vaporizes liquid fuel and premixes with primary air. A vaporization chamber for generating a premixed gas containing a vaporized gas in response to the spraying of liquid fuel from the nozzles, a vaporization mixing chamber for promoting vaporization and mixing of the premixed gas from the vaporization chamber, and the vaporization chamber; Providing a jetting portion that communicates with the vaporizing and mixing chamber and jets the premixed gas generated in the vaporizing chamber toward the inner wall of the vaporizing and mixing chamber, and further provides an orifice at the inlet of the vaporizing chamber; A fuel reforming burner characterized in that the tip of the nozzle is disposed in the vicinity of the orifice.   The orifice portion includes a throttle portion that is tapered toward the vaporization chamber side, and a communication portion that communicates the throttle portion and the vaporization chamber, and the tip portion of the nozzle is disposed in the throttle portion. 2. The fuel reformer burner according to claim 1, wherein the burner is a fuel reformer.   The nozzle tip is cut at an acute angle from the front and back to the tip to form a windbreak wall on both sides, the windbreak wall is cut at an acute angle toward the tip, and the jetting portion The fuel reforming burner according to claim 1 or 2, wherein the nozzle is arranged so that an axial direction of the nozzle and a linear direction formed by connecting tips of the windbreak walls substantially coincide with each other.

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