JP2002071108A - Combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent combustion device good in its combustion heat recovery efficiency and capable of preventing imperfect combustion and the thermal deformation of a heat receiving plate. SOLUTION: The combustion device comprises a fuel supply part 5 for supplying fuel liquid, a vaporizing part 3 for vaporizing the supplied liquid fuel, a fire port 2 having a combustion surface 21 for burning the liquid fuel vaporized in the vaporizing part 3, an air supply part 6 for supplying air to the vaporizing part 3 and the fire port 2 and an ignition part 7 for igniting the mixed gas of the vaporized fuel discharged from the burner holes 22 of the fire port 2 and the supplied air. The combustion surface 21 of the fire port 2 is formed in one plate having a plurality of burner holes 22 and has a protruding part 4 protruding to the side of the fire port 2 to recover heat upon combustion to the vaporizing part 3. On a plane of projection of the protruding part 4 to the fire port 2, at least one air holes 23 for jetting the air fed from the air supply part 6 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater mainly used for domestic hot water supply, heating, water heating for bath reheating and the like, or a liquid fuel such as kerosene used for a multifunction machine thereof. The present invention relates to a combustion device for vaporizing and burning.

[0002]

2. Description of the Related Art The present applicant has already proposed a combustion apparatus in Japanese Patent Application No. 11-298208 as prior art of the present application. In this prior combustion device, a plurality of vertical plate-shaped heat receiving plates are provided on the crater side (crater) side of the vaporizing part (vaporizer), and heat is recovered to the vaporizing part.

[0003]

However, the conventional combustion apparatus has the following problems. a. Since the heat receiving plate does not protrude significantly to the crater side, the amount of heat recovered during combustion is small and the vaporization temperature cannot be maintained by the temperature detection means.Therefore, it is necessary to energize the heater to maintain the temperature of the vaporization section, increasing power consumption. There was a problem of doing.

B. Further, when a heat receiving plate is provided above the flame hole, there is a problem that combustion of the combustion device is poorly performed because combustion of the flame hole is obstructed.

C. b. When the heat receiving plate is provided so as to avoid the upper part of the flame hole for the reason described above, there is a problem that the heat recovery amount is further reduced.

D. Further, since the heat receiving plate is a plate extending in the vertical direction, the distance from the flame hole is short at the bottom of the heat receiving plate, and b. In the case of, further combustion failure occurs, and c. Also in the case of (1), since only the lowermost part is close to the flame, there is a problem that a local temperature rise occurs and thermal deformation occurs.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a combustion apparatus capable of efficiently preventing heat recovery, defective combustion and thermal deformation of a heat receiving plate.

[0008]

A combustion apparatus according to the present invention comprises a fuel supply section for sending liquid fuel, a vaporization section for vaporizing the supplied liquid fuel, and a combustion surface for burning the liquid fuel vaporized by the vaporization section. A crater portion, a blast portion for sending air to the vaporization portion and the crater portion, and an ignition portion for igniting a mixture of vaporized fuel and air sent from a flame hole of the crater portion. In the combustion device, the combustion surface of the crater portion is a single flat plate having a plurality of flame holes, and has a protrusion protruding toward the crater portion and recovering heat during combustion to the vaporizing portion. In the projection plane to the crater part, to have an air hole to blow out the air sent from at least one or more of the blowing unit,
In addition, if added, the protrusion may protrude toward the crater side from a substantially central portion of the width of the vaporized portion, or the relationship between the height and the width in the cross-sectional shape of the protrusion protruding from the vaporized portion may be a height. Is smaller than the width, and the surface of the protrusion facing the crater has a concave groove from the tip of the protrusion to a position connected to the outside of the vaporization part of the protrusion. And

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a combustion apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of the combustion device, FIG. 2 is a plan view of FIG.
(A) and FIG. 3 (b) are a side view and a cross-sectional view of the protrusion according to claim 3, and FIGS. 4 (a) and (b) are a side view and a cross-sectional view of the protrusion according to claim 4. is there. In the description of each part, the same portions are denoted by the same reference numerals and description thereof will be omitted.

In the schematic sectional view of the combustion apparatus of the present invention shown in FIG.
1 is a combustion device for vaporizing and burning the liquid fuel of the present invention,
Reference numeral 2 denotes a crater portion composed of a single flat crater in which the vaporized fuel of the combustion device 1 burns. Reference numeral 3 denotes air upstream of the crater portion 2 which vaporizes liquid fuel and is sent from a blower described later. The vaporizing section 4 is mixed with the vaporizing section 3 on the crater 2 side.
Is a protruding portion formed by protruding a part of the outer surface of the device, and is called a heat receiving plate in the conventional example. Reference numeral 5 denotes a fuel supply unit which is, for example, an electromagnetic pump with a shut-off valve having a fuel delivery means for supplying liquid fuel to the combustion apparatus 1 and a liquid fuel delivery stop means, and 6 supplies air to the combustion apparatus 1 to vaporize it. A blower unit for supplying primary air premixed with the liquid fuel and secondary air which is air for combustion in the crater part 2 ignites the air-fuel mixture sent to the crater part by discharge or red heat of a resistance wire. The ignition portion 21 is a combustion surface on which the vaporized fuel and air of the crater portion 2 are burned, 22 is a flame hole formed at a predetermined interval in the combustion surface 21, and 23 is a hole penetrating the crater portion. An air hole through which only the air from the blowing unit 5 passes, 31 is a vaporizing surface in the vaporizing unit 3 where liquid fuel dropped from a fuel nozzle, which will be described later, is vaporized by heat or the like collected by the protrusion 4, 32 is Start combustion by closely or buried in the vaporizer 3 A heater made of a resistor such as a nichrome wire for raising the temperature of the vaporizing surface 31 to a predetermined temperature when the heat generated by the combustion of the fuel cannot be recovered, and 33 is an optimal vaporizing temperature of the liquid fuel embedded in the vaporizing section 3. , A reference numeral 51 denotes an oil tank that stores liquid fuel and supplies it to the combustion device 1. Reference numeral 52 denotes a liquid fuel in the oil tank 51 which is sent out by the fuel supply unit 5 to the vaporizing surface. 31 is a fuel nozzle for discharging.

Further, the material of the vaporizing portion 3 and the projecting portion 4 which are essential parts of the present invention is a metal material having heat resistance and good conduction and heat transfer. When the liquid fuel is vaporized, a material having a certain thickness is preferable because it is better to be able to store the heat quantity. Therefore, considering these contents, and considering the manufacturing aspect, as a method suitable for mass-producing a complex shape, a method that is integrally formed by forging or casting, or a method in which a projection and a vaporization part are separately provided. Each is formed by forging or casting, and then the projection and the vaporized portion are joined by welding, fitting with screws, or the like, which is suitable for the above-described contents. Therefore, it is common to use a forged or cast material such as a copper alloy or an aluminum alloy in the same manner as in the conventional example. Also, it can be carried out by dividing the vaporized portion into a plurality of members, processing a part or all of them by a die such as a press, and thereafter integrally forming them by welding (welding), caulking, fitting with screws, or the like. .

The operating method of the combustion apparatus 1 will be described. First, a combustion start command from the outside, for example, when the combustion apparatus is a water heater, the combustion apparatus 1 detects a decrease in temperature or running water to detect the temperature. The temperature of the vaporizing surface 31 of the vaporizing section 3 is adjusted so that the temperature of the liquid fuel becomes a temperature at which the liquid fuel can be vaporized.
To raise the temperature. When the temperature detector 33 detects a temperature at which the liquid fuel can be vaporized, the blower 6 starts blowing, and the ignition unit 7 starts discharging or glowing when the rotation speed reaches a predetermined airflow, and with a slight delay. When the fuel supply unit 5 is driven, liquid fuel is sent from the tip of the fuel nozzle 52 to the vaporizing surface 31, and the liquid fuel is vaporized on the vaporizing surface 31 heated to a vaporizable temperature by the heater 32, And is sent to the crater 2. The gaseous mixture of vaporized liquid fuel and air sent into the crater portion 2 is blown out from a plurality of flame holes 22 formed in the combustion surface 21 and ignited by an ignition source such as discharge or red heat already started by the ignition portion 7. I do.

When the combustion starts, the projections 4 protrude from the combustion surface 21 having the flame holes 22, so that the projections 4 receive heat due to the flame ejected from the flame holes 22, and receive the heat because the projections 4 are connected to the vaporizing section 3. The heat is conducted and transferred to the vaporizing section 3. Therefore, when a predetermined time elapses after the start of combustion, the vaporization unit 3 can receive heat by combustion heat without depending on the heating of the vaporization unit 3 by the heater 32.

Further, an air layer and an air flow are generated around the projection 4 by the secondary air ejected from the air holes 23, and the air layer is opposed to the projection 4 or in the vicinity of the position facing the projection 4. The flame emitted from a certain flame hole 22 rises while slightly bypassing the projection 4 by the air layer so as not to directly touch the projection 4. In addition, the combustion heat of the flame is reduced by the air flow to the crater 2 of the projection 4.
The combustion heat is applied to the protruding portion 4 so as to wrap around and wrap around not only the surface facing, but also the side and upward. Of course, the projections 4 will be cooled by the secondary air, but since the combustion surface 21 and the projections 4 have a predetermined interval, the surroundings will be reached before the secondary air reaches the projections 4. The heat is mixed by the heat of combustion coming out of the flame holes and becomes a temperature slightly lower than the heat of combustion, and has little effect on the heat recovery to the vaporizing section 3.

The purpose of the relationship between the combustion surface 21 and the projection 4 is that the projection 4 receives combustion heat from the combustion surface 21.
The optimal temperature for vaporizing liquid fuel is a certain range of temperature lower than the combustion temperature, and it is not good to receive combustion heat too much or conversely to the extent that it does not reach the vaporization temperature. Therefore, it is determined by experiments that the heat of combustion is received (recovered) to such an extent that the vaporization temperature can be maintained. Further, if the protrusion 4 is too large with respect to the combustion surface 21, the combustion is hindered, causing a combustion failure or a decrease in heat efficiency for exchanging heat of combustion with a heat exchanger or the like.

FIG. 2 is a plan view of FIG. 1 and explains the structure of the second embodiment. Reference numeral 11 denotes a crater tip space through which secondary air at the tip of the crater 2 passes, and 12 denotes a crater. A crater right space on the right side of the part 2 through which the secondary air passes, and a crater left space 13 on the left side of the crater part 2 through which the secondary air passes. The protruding portion 4 protrudes from a position facing the vicinity of a portion where the liquid fuel discharged from the fuel nozzle 52 mainly vaporizes from the outside of the vaporizing portion 3, and the crater portion 2 is indicated by a broken line in the projection plane of the protruding portion 4. There is an air hole 23 at the position shown.

At this time, the fuel nozzle 52 is provided at the center of the vaporizing section 3 because it is necessary to uniformly vaporize the inside of the vaporizing section 3 and supply the vaporized liquid fuel and the mixed air to the crater section 2. The projection 4 is located in the vicinity of the vaporizing surface 31 facing the tip of the combustion nozzle 52 where the effect that the liquid fuel delivered from the tip of the combustion nozzle 52 is quickly vaporized and the recovered heat is continuously supplied is maximized. Would be better,
Therefore, it is better that the protrusion 4 is provided at a substantially central portion outside the vaporizing portion 3. Another reason is that Figure 2
As shown in the figure, the periphery of the crater 2 is a crater tip space 11 and a crater right space 12 which are spaces (gap) through which secondary air for combustion passes.
And a crater left space 13. Therefore, if the projection 4
When the projection 4 is provided in the vicinity of the crater right space 12 or the crater left space 13 which is the end of the vaporization part 3 in the positional relationship with the combustion surface 21, one side of the projection 4 is affected by the surrounding secondary air. The temperature is low and the temperature on the side close to the other combustion surface 21 is high, and if a normal metal is used, the higher the temperature, the greater the expansion. Therefore, non-uniform thermal expansion due to the temperature difference will occur. It is better to be in a position where the center of 21 receives the combustion heat stably. Therefore,
As shown in FIG. 2, the projection 4 has a single rod shape and projects from the center of the vaporization part 3 toward the crater 2.

FIG. 3A shows a projection 4 according to the third aspect.
The liquid fuel is delivered from one end of the fuel nozzle 52 as shown in FIG.
The projection 41 is formed because the combustion heat tends to concentrate at a position facing the vaporizing section 3 in the vicinity where the liquid fuel is delivered and vaporized.
Is a single rod, the width W is made larger than the height H (H <W) in order to effectively recover the combustion heat. This is because if the height is made thicker than necessary,
1 has a problem that it is difficult to uniformly apply heat to the protrusions 41 because the temperature difference occurs between the upper surface and the lower surface of the air outlet 1. The width dimension is determined by the hole diameter of the air holes 23 and the amount of air diverted from the blower 6. Required by Here, FIG.
In (a), the cross-sectional shape of the projection 41 is substantially the same (H1 ≒ H2, W1 ≒ W2) in the cross-sectional shape AA at the tip and the cross-sectional shape BB on the side closer to the vaporization section 3. In another embodiment, FIG.
Cross-section at the tip end of the cross section CC and the cross-section at the intermediate position DD
Has a similar shape that becomes larger toward the position connected to the outside of the vaporizing portion 3 from the tip, so that the cross-sectional shape DD at the intermediate position is larger (H3 <H4, W3 <W4), and furthermore, it is vaporized. Since there is no opposed flame hole 22 near the position connected to the outside of the portion 3, the cross-sectional shape EE is further increased (H3 <H4 <H5, W3 <W4 <W5). Generally, increasing the cross-sectional shape from the tip to the position connected to the outside of the vaporization section 3 from the tip end, as in the case of the projection 42, is superior in both durability and workability.

FIG. 4A shows a projection 4 according to a fourth aspect of the present invention.
3 is a sectional view of FIG. Reference numeral 43 denotes a protrusion, and reference numeral 44 denotes an inverted concave groove having a depth h and a width w extending from the end of the surface of the protrusion 43 facing the crater 2 to the root. The groove 44 faces the air hole 23 and the air hole 2
A part of the air ejected from 3 is guided by the groove 44 and flows to the front end and the connecting portion outside the vaporizing section 3. As a result, the air layer and the air flow also cover the length direction of the projection 4, and the flame from the flame hole 22 which is opposed to the projection 43 or in the vicinity of the projection 43 does not directly touch. Since poor combustion does not occur over the entire projection, and the combustion heat around the projection is received substantially evenly, deformation due to heat does not occur. Here, in FIG. 4A, the cross-sectional shape FF of the distal end portion of the protrusion 43 and the cross-section at a position connected to the outside of the vaporization part 3 are substantially the same as the depth and width of GG. Uniform (h1 ≒ h2, w1 ≒ w2).
In another embodiment, in FIG.
5. With the groove as 46, the cross section of the tip of the projection 45 is H-
H, the cross section of the protrusion 45 facing the air hole 23 is II,
Assuming that the cross section connected to the outside of the vaporization portion 3 is JJ, the relationship between each depth and each width of the groove 46 is such that the depth or / and width of the cross section II at the position facing the air hole 23 is determined. It is made deepest and / or widest, and shallower and / or narrower toward the position connected to the tip and the outside of the vaporizing part 3. In other words, the cross-sectional area of the groove 46 in the cross-section II of the protrusion 45 facing the air hole 23 is the largest, and the cross-sectional area decreases toward the end and the position connected to the outside of the vaporization section 3. Therefore, this relationship is w3 × h3 <w4 × h4, and
And w5 × h5 <w4 × h4. The shape as shown in FIG. 4 (b) distributes the air blown out from the air holes 23 better from the tip of the projection 46 to a position connected to the outside of the vaporization section 3, so that heat recovery and the like become uniform. easy.

As described above, the combustion apparatus according to the embodiment has the following functions. a. In claim 1, an air layer that prevents the flame from directly touching the projection by the secondary air from the secondary air hole even when the projection is inserted into the crater at a position where heat recovery can be more easily performed. It has the effect of forming and applying heat evenly around the projections by the agitating action of the flame by the air flow. b. According to the second aspect, in addition to the effect of the a, the vaporization of the liquid fuel is effective because the protrusion protrudes from the outside of the vaporization section facing the vicinity of the position where the fuel nozzle discharges and vaporizes the liquid fuel. And has the effect that it can be performed quickly. c. According to the third aspect, in addition to the function b, the heat recovery amount is increased. d. In claim 4, in addition to the action of b or c, an air layer and an air flow are formed in the longitudinal direction over the joint of the projection with the vaporizing portion and the tip, and a flame is generated over the entire projection. It has the effect of preventing direct contact and applying heat more uniformly over the entire projection.

[0021]

According to the present invention, this combustion apparatus has the following effects. a. In claim 1, an air layer that prevents the flame from directly touching the projection by the secondary air from the secondary air hole even when the projection is inserted into the crater at a position where heat recovery can be more easily performed. By forming and having the function of uniformly applying heat around the protrusions by the stirring action of the flame by the air flow, it has excellent performance of recovering combustion heat, prevents deformation due to heat, and also prevents poor combustion. It has the effect of. b. According to the second aspect, in addition to the effect of the above a, the protrusion of the projection protrudes from the outside of the vaporizing portion facing the vicinity of the position where the liquid fuel vaporizes, so that the liquid fuel can be vaporized effectively and quickly. Therefore, there is an effect that the vaporization performance of the liquid fuel is excellent. c. According to the third aspect, in addition to the effect of b, the heat recovery amount is increased, so that the combustion heat can be recovered without increasing the cross section of the projection. In the case where the projection and the vaporized portion are integrally formed by forging or casting, there is also an effect that the processing is easy because the cross-sectional area of the projection is small. d. In claim 4, in addition to the effect of b or c, an air layer and an air flow are formed in the longitudinal direction over the joint of the projection with the vaporizing portion and the tip, and a flame is generated over the entire projection. Prevents direct contact, and has the effect of applying heat more uniformly over the entire projection, preventing local combustion failure such as soot adhesion by the projection,
This has the effect of preventing deformation of the protruding portion and at the same time excelling in the performance of recovering combustion heat.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a combustion device of the present invention.

FIG. 2 is a plan view of FIG.

FIGS. 3A and 3B are a side view and a cross-sectional view of a protrusion which is a main part of the present invention, and show another embodiment in FIGS.

FIG. 4 is a side view and a cross-sectional view of a projection which is a main part of the present invention, and shows another embodiment in (a) and (b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion apparatus 2 Crater part 3 Vaporization part 4, 41, 42, 43, 45 Projection part 5 Fuel supply part 6 Blower part 7 Ignition part 11 Crater tip space 12 Crater right space 13 Crater left space 21 Combustion surface 22 Flame hole 23 Air Hole 31 Vaporized surface 32 Heater 33 Temperature detector 44, 46 Groove 51 Oil tank 52 Fuel nozzle

Claims (4)

[Claims] 1. A fuel supply unit for sending liquid fuel, a vaporizing unit for vaporizing the sent liquid fuel, a crater having a combustion surface for burning the liquid fuel vaporized by the vaporizing unit, the vaporizing unit, In a combustion device having a blower that sends air to a crater, and an igniter that ignites a mixture of vaporized fuel and air sent from a flame hole of the crater, a combustion surface of the crater includes: One flat plate having a plurality of flame holes, having a protrusion protruding toward the crater side and collecting heat during combustion to the vaporizing portion, and at least one projection within the projection surface of the protrusion to the crater portion. A combustion device having an air hole for ejecting air sent from one or more of the blowers. 2. The combustion apparatus according to claim 1, wherein the projection projects from a substantially central portion of a width of the vaporizing portion toward the crater. 3. The combustion apparatus according to claim 2, wherein the relationship between the height and the width in the cross-sectional shape of the protrusion protruding from the vaporizing portion is such that the height is smaller than the width. 4. The projection has a concave groove on a surface of the projection facing the crater from a tip of the projection to a position connected to the outside of a vaporization part of the projection. The combustion device according to claim 3.