JP2003302009A - Evaporator element for vaporising burner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve use of energy given by an ignition mechanism for evaporating a fuel. <P>SOLUTION: This evaporator element 18 to be positioned on a combustion chamber wall 16 has a cutout 26 formed therein for storing at least part of the ignition mechanism 20. When it is positioned with the ignition mechanism 20 engaging the cutout 26, a cutout wall 30 encircles at least part of the ignition mechanism 20. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporating element used in an evaporative burner, particularly for a vehicle heating system.

[0002]

2. Description of the Related Art Used in an automobile, for example, as a stand-alone heating system (Standheizung) separate from the engine or an auxiliary heater (Zuheizer) which can be operated even before the vehicle is driven or when the engine is stopped during idling stop operation. In evaporative burners, fuel is fed through a fuel line to an evaporative element positioned at the combustion chamber wall and at least partially lining the combustion chamber. The vaporizing element distributes the fuel supplied to the vaporizing element by capillary action, possibly even under a preformed fuel pressure, and towards the surface of the vaporizing element facing the combustion chamber. Formed for pumping. A device of this type is shown schematically in FIG. The combustion chamber housing 10a can be seen here. The combustion chamber housing 10a surrounds the combustion chamber 12a formed therein with a combustion chamber outer wall 14a and a combustion chamber bottom wall 16a. The combustion chamber bottom wall 14a is provided with a vaporization element 18a which covers the combustion chamber bottom wall 14a almost completely and is formed in a planar shape from a porous material or a braided or knitted material. Has been. Glow ignition sheath
Ignition mechanism 2 formed in the form of a hzuendshift)
0a penetrates the outer wall 14a of the combustion chamber, and the ignition mechanism 20
Region 22 of a, which is effective for generating the ignition temperature
It is located inside the combustion chamber 12a at a, and is located at a slight distance in front of the planar evaporation element 18a. That is, the situation schematically shown in FIG. 7 is obtained. In this situation, the ignition mechanism 20a is located opposite the substantially flat surface of the evaporation element 18a with a small spacing a in the region 22a which is effective for generating the ignition temperature. Evaporating element 18a
The distance between the ignition mechanism 20a and the surface of the evaporation element 18a increases as the distance from the point 0 where the ignition mechanism 20a is opposed to the surface of the ignition element 20a with the minimum distance increases. Is recognized. Correspondingly, the line connecting the ignition mechanism 20a to each point on the surface of the evaporation element 18a and the evaporation element 18a
The angle of incidence with the surface of the is reduced. Primarily, the evaporating element 18 provides the necessary temperature for ignition and forms an ignitable or combustible mixture.
The ignition mechanism 20a provided to evaporate the fuel concentrated from a transfers heat energy to the evaporation element 18a in the form of substantially radiation heat. The transferred thermal energy decreases at a distance between the ignition mechanism 20a and each surface region based on a graph of a quadratic function and also decreases as the incident angle decreases. As a result, a significant portion of the thermal energy provided by the ignition mechanism 20a cannot actually be effectively used for evaporation or ignition.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to improve the evaporating element used in evaporative burners, in particular for vehicle heating systems, in order to increase the energy provided by the ignition mechanism for the evaporation of fuel. It is to improve it so that it can be used.

[0004]

In order to solve this problem, in the structure of the present invention, the evaporation element is formed for positioning on the wall of the combustion chamber and at least partially houses the ignition mechanism. Has a notch for
The notch wall at least partially surrounds the ignition mechanism when the ignition mechanism is engaged and positioned within the notch.

[0005]

In the vaporizing element according to the invention, this vaporizing element at least partially surrounds the ignition mechanism, which is different from the known planar arrangement according to the known prior art, whereby FIG. The unfavorable situation shown in is eliminated, not only with respect to the angle of incidence,
Even with regard to the distance between the ignition mechanism and the surface of the evaporation element, in particular in the region of the cutout wall, a situation is also provided which allows improved radiation energy transfer.

In this case, it is particularly advantageous if the notch is formed so that its wall surrounds at least one region of the ignition mechanism which is effective for generating the ignition temperature.

In order to allow as uniform a heat transfer as possible between the ignition mechanism and the surface of the evaporation element, in an advantageous configuration of the invention, the ignition mechanism is at least partially engaged in the cutout. The cutout wall surrounds the ignition mechanism in at least a partial area of the cutout wall with a substantially uniform spacing when positioned in this manner. In this case, the heat transfer can also be improved by the notches being elongated to fit the elongated shape of the ignition mechanism.

In order to assist as much as possible the evaporation of fuel from the evaporating element towards the combustion chamber and to prevent as much as possible the release of heat from the ignition mechanism towards the wall of the combustion chamber, the present invention In an advantageous construction of the notch, the notch is opened toward the side of the evaporation element facing the combustion chamber where it is desired to be positioned, and the ignition mechanism is positioned in engagement with the notch in the combustion chamber wall. The facing side is surrounded by a cutout wall.

The cutout wall encloses the ignition mechanism, which is positioned in engagement with the cutout in an angular range of at least 150 °, to achieve a very effective transfer of radiation heat to the evaporation element. be able to.

The evaporation element can be formed from a porous material or a braided material. Here, for example, steel braids or other foam-like materials, for example foam ceramics, are considered.

According to another advantageous embodiment of the invention, the evaporation element is formed in the shape of a substantially disk or an annular plate (ring disk), the notch extending substantially in the radial direction for evaporation. Formed on the working element and open radially outward.

The present invention further relates to an evaporative burner. In this case, there is provided a combustion chamber housing having a combustion chamber outer wall and a combustion chamber bottom wall forming a combustion chamber, one of the combustion chamber walls, preferably the combustion chamber bottom wall, having an evaporation element according to the invention. And the ignition mechanism is positioned in engagement with the notch in the evaporation element.

In order to be able to form the evaporating element from a relatively thin material despite the provision of the notch in the evaporating element, in an advantageous embodiment of the invention, the combustion chamber wall There is a recess on one side,
An evaporation element is engaged in the recess in the area having the cutout.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

1-3, there is provided an evaporating element 18 made of a porous material or other material that can be used to pump fuel under capillarity, formed in accordance with the principles of the present invention. The combustion chamber housing 10 is shown.
Also in the case of this device, in the example shown, the combustion chamber housing 10, which provides a cylindrical shape to the combustion chamber 12, has a combustion chamber outer wall 14 and a combustion chamber bottom wall 16. An evaporation element 18 is arranged on the side of the combustion chamber bottom wall 16 facing the combustion chamber 12. The ignition mechanism 20, which is also formed in the form of a glow ignition sheath, comprises a combustion chamber housing 1
0 through the opening 24 of the combustion chamber outer wall 14 from the outside in the radial direction with respect to the longitudinal axis L of the evaporation element 1
8 extends radially into a notch 26 provided in 8.
This notch 26 is open on the side of the evaporation element 18 facing the combustion chamber 12 and has a partially circular cross-section, as can be seen in particular from FIG. . The depth of the cutout 26 is the cutout 2 when the ignition mechanism 20 engaged in the cutout 26 is viewed in the direction of the longitudinal axis L.
It is dimensioned for almost complete engagement within 6.
In the radially outer region, the notch 26 is formed by the notch 2
6 is open to allow radial engagement of the ignition mechanism 20 into 6. The notch 26 is also formed to be elongated so as to conform to the elongated shape of the ignition mechanism 20. In the area near the longitudinal end 28 of the ignition mechanism 20, a notch 26 formed with an elongated shape is also formed correspondingly to the shape of the end area 28 of the ignition mechanism 20. There is.

Therefore, the notch wall 30 is attached to the ignition mechanism 20.
It is possible to obtain a configuration in which most of the extended length of the ignition mechanism 20 is surrounded by the longitudinal axis L of the ignition mechanism 20 at substantially uniform intervals in the circumferential direction. In this case, a small intermediate chamber is left between the ignition mechanism 20 and the cutout wall 30 in order to enable the generation of a concentrated atmosphere by the evaporated fuel.

Since the evaporating element 18 is formed of a material having a thickness dimensioned smaller than the thickness of the ignition mechanism 20, the evaporating element 18 is substantially located in the area where the notch 26 is formed. It also has a bulge corresponding to the contour of the notch 26. In order to enable the planar positioning of the evaporation element 18 on the combustion chamber bottom wall 16,
The combustion chamber bottom wall 16 has a recess 32 corresponding to the required bulge shape provided on the evaporation element 18. In the region of the recess 32, the opening 3 is formed in the combustion chamber bottom wall 16.
4 are formed. In this case, the fuel is introduced into the evaporation element 18 through the opening 34. In this case, as can be seen from FIG. 1, this introduction is preferably carried out in the region where the evaporation element 18 has a bulge. The air required for combustion is pumped into the combustion chamber 12 via the air introduction opening 36, for example. The air introduction opening 36 is formed in the outer wall 14 of the combustion chamber at a slight distance from the bottom wall 16 of the combustion chamber.

In the configuration shown in FIGS. 1 to 3, the cutout wall 30 is elongated in the longitudinal central axis line of the ignition mechanism 20 by providing the ignition mechanism 20 and the cutout 26 in harmony with each other. A situation is obtained in which the ignition mechanism 20 is surrounded with a substantially constant distance in an angular range of about 180 ° with respect to the angle γ. This is also clearly shown in FIG. In this case, the distance between the ignition mechanism 20 and the cutout wall 30 increases only in the transition region of the cutout wall 30 into a section formed with a partially linear contour instead of a circular contour. is doing. The same applies to the axial end region 28 of the ignition mechanism 20.

Compared with the devices known from the known prior art, in particular, the evaporation element 1 formed according to the invention.
The advantage of 8 in terms of heat transfer is also shown in FIG. In FIG. 5, the solid line, without the crosses, represents the relative radiation intensity produced in relation to the distance to the point of vertical radiation incidence directed at the evaporation element. At the point of vertical incidence, that is, at point 0, 10
It is observed that although a maximum of 0% is given, there is a significant decrease with increasing distance from this point of vertical radiation incidence. By comparison, the line marked with a cross indicates the corresponding curve obtained when using the evaporation element 18 according to the invention. It will be appreciated that maximum radiation heat transfer is obtained in the region where the evaporating element 18 surrounds the ignition mechanism 20 with its notch wall 30 at a substantially constant distance. After that, the radiation intensity decreases only in the region where the deviation from the constant distance between the notch wall 30 and the ignition mechanism 20 occurs. Based on this, it can be seen that the radiation energy emitted from the ignition mechanism 20 is transferred to the evaporation element 18 in a very efficient manner, so that the evaporation rate is significantly improved with the same supplied radiation energy. This makes it possible to provide the ignitable or combustible mixture in the region of the ignition mechanism 20 very quickly, so that both the ignition and the transition to normal combustion operation proceed very rapidly. As a result, a significantly reduced amount of harmful substances is obtained in the ignition operation state.

An alternative construction of the evaporation element 18 is shown in FIG. Here, the notch 26 provided to house the ignition mechanism 20 is its notch wall 30 which causes the ignition mechanism 20 which engages in the notch 26 to be spaced at a substantially constant distance in the angular range of approximately 270 °. It is formed so as to surround. As a result, in FIG. 5, the plateau having a radiation intensity of 100% can be further expanded over the entire circumference of the ignition mechanism 20, and therefore radiation heat can be used more efficiently. However, here too, the vaporization element 18 opens towards the combustion chamber 12 in the region of the cutout 26 in order to allow the outflow of vaporized fuel from the cutout 26 in the direction of the combustion chamber 12. ing.

It has, of course, been found that the cutouts provided in the evaporation element according to the invention may also have different shapes, in order to accommodate different shaped ignition mechanisms. Also, the extending direction of the notch may be different to accommodate the extending direction of the ignition mechanism, and possibly another extending direction. Of course, it is also possible to use the evaporation element according to the invention in an annularly formed combustion chamber. In this case, in this combustion chamber, the evaporation element may be formed in an annular shape so as to fit the annular combustion chamber bottom, and in this case, a notch for engaging the ignition mechanism is provided in the peripheral region. is doing. Basically, the evaporation element according to the invention makes it possible, in the case of the outer wall of the combustion chamber or of an annular design, also the inner wall of the combustion chamber, such as a cylindrical sleeve, in some cases. In this case, the evaporation element is, for example, the longitudinal axis L.
May be engaged axially through the bottom of the combustion chamber and then in a notch that opens axially towards the bottom of the combustion chamber and extends approximately axially into the evaporation element.

[Brief description of drawings]

1 is a longitudinal sectional view of a combustion chamber housing in which the evaporation element according to the present invention is used, which is taken along the line I-I shown in FIG.

2 is a cross-sectional view of the device shown in FIG. 1, taken along line II-II of the device shown in FIG.

3 is another longitudinal cross-sectional view of the device of FIG. 1, taken along the line III-III shown in FIG.

FIG. 4 is a diagram showing an alternative configuration of the evaporation element.

FIG. 5 is a graph showing the relationship of radiation energy transfer from an ignition mechanism considered as a point-like radiation source to a predetermined surface.

FIG. 6 is a principle diagram showing the spacing relationship between a radiation source and a surface in an evaporation element according to the present invention.

FIG. 7 is a view corresponding to FIG. 6, showing the relationship between the distance and the position of the evaporation element with respect to the surface in the known device according to the known prior art.

FIG. 8 is a longitudinal sectional view of a combustion chamber known from the known prior art, with an evaporation element arranged at the bottom of the combustion chamber.

[Explanation of symbols]

10, 10a Combustion chamber housing, 12, 12a Combustion chamber, 14, 14a Combustion chamber outer wall, 16, 16a Combustion chamber bottom wall, 18, 18a Evaporating element, 2
0,20a ignition mechanism, 22,22a area, 24
Opening, 26 notch, 28 end region, 30 notch wall, 32 recess, 34 opening, 36 air inlet opening, L longitudinal axis

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Michael Hunburg             Federal Republic of Germany Göppingen Fal             Kenstraße 57 F term (reference) 3K047 BA02 BA06 BB07 BB14

Claims (10)

[Claims] 1. An evaporating element for use in an evaporative burner, particularly for a vehicle heating system, wherein the evaporating element (18) is formed for positioning on a combustion chamber wall (16) and has an ignition mechanism. Has a notch (26) for at least partially containing (20),
When the ignition mechanism (20) is engaged and positioned in the notch (26), the notch wall (30) causes the ignition mechanism (2) to move.
0) at least partially surrounding 0), an evaporating element for use in an evaporative burner. 2. The cutout (26) has a cutout wall (3).
The evaporation element according to claim 1, which is formed so as to surround at least one region (22) of the ignition mechanism (20) which is effective for generating an ignition temperature. 3. The cutout wall (30) at least partially extends the ignition mechanism (20) when the ignition mechanism (20) is positioned at least partially engaged and positioned within the cutout (26). Evaporation element according to claim 1 or 2, which encloses the subregion 30) at substantially uniform intervals. 4. Evaporation according to any one of claims 1 to 3, wherein the notch (26) is formed to be elongated so as to fit the elongated shape of the ignition mechanism (20). element. 5. The notch (26) is open towards the side of the evaporation element (18) that faces the combustion chamber (12) and is to be positioned and engages in the notch (26). Combustion chamber wall (16) of the ignition mechanism (20) positioned in position
Evaporation element according to any one of the preceding claims, wherein the side facing the is surrounded by a notched wall (30). 6. The cutout wall (30) encloses the ignition mechanism (20) engaged and positioned in the cutout (26) at an angle range of at least 150 °. The evaporation element according to any one of 1. 7. The evaporation element according to claim 1, wherein the evaporation element (18) is made of a porous material or a braided material. 8. The evaporation element (18) is formed in a substantially disk shape or an annular plate shape, and has a notch (2).
Evaporating element according to any one of claims 1 to 7, characterized in that 6) extends substantially radially and is formed in the evaporation element (18) and is open radially outward. 9. In an evaporative burner, a combustion chamber (12)
And the combustion chamber outer wall (14) and the combustion chamber bottom wall (16) that form the
A combustion chamber housing (10) is provided, which comprises one of the combustion chamber walls (14, 16), preferably the combustion chamber bottom wall (16). Of the evaporation element (18) is provided, and the ignition mechanism (20) is provided with a notch (2) of the evaporation element (18).
6) An evaporative burner characterized by being positioned in engagement within. 10. A recess (32) is provided in one of the combustion chamber walls (14, 16) in which the evaporation element (18) has a notch (26). The evaporative burner according to claim 9, which is engaged.