RU2361147C2 - Heater injector with updated reflector plate - Google Patents

Abstract

FIELD: heating. ^ SUBSTANCE: invention relates to power engineering. The proposed heater injector, intended for, in particular, trackless vehicles with motor drive, incorporates the combustion chamber symmetric to the chamber axis and reflector plate fitted there inside and furnished with preset axial camber directed towards the burn-out zone. The reflector plate outer circumference sets the plane. The maximum axial distance of the said reflector plane from aforesaid plane vs the plate diametre varies from 0.07 to 0.21. The injector incorporates also the fuel and primary air feed injector cone. The heat shield is arranged between the injector cone and combustion chamber. Note that the said heat shield incorporates orifices to feed secondary air into combustion chamber, the said orifices being furnished with air guide elements. Previously mentioned elements are formed by tabs extending towards the combustion chamber and made integral with previously mentioned heat shield, the said tabs being fitted at different angles to the latter and/or to its radius. The said tabs represent sets of tabs with equal angles to the heat shield and/or its radius. The injector features the starting and burn-out zones. Secondary air fed into the burn-out zone features larger eddying than that fed into the starting zone. The said heat shield has the firing element-receiving orifice. The injection cone features injector needle to feed fuel into the injector and primary air for combustion. Selecting the injector needle OD allows setting the fuel feed rate so that to make fuel reach the starting zone in non-sprayed form. The needle ID varies from 0.5 mm to 0.7 mm. ^ EFFECT: reliable operation of injector. ^ 12 cl, 3 dwg

Description

The invention relates to a nozzle for a heating device, in particular for use in trackless vehicles with a motor drive, with a combustion chamber substantially symmetrical about the axis and a reflective disk located in the combustion chamber.

These nozzles, which are also called spray nozzles or spray nozzles, are used, in particular, with additional heating and stationary heating for rail-powered vehicles with a motor drive.

There are numerous requirements for such nozzles, in particular, those that reliably start up to a large extent and are free from emissions, as well as a stable combustion mode. Next, they strive to design heating devices so that they can be used in various positions during installation.

With regard to starting characteristics, different operating parameters must be coordinated with each other. Firstly, during start-up of the nozzle, it is required that there is a relatively oily air-fuel mixture in the start-up zone, and, on the other hand, it is necessary to prepare a sufficient amount of primary combustion air to ensure the transportation of fuel from the nozzle needle to the start-up zone.

The requirement for the heater to be installed in various positions is associated with problems regarding starting performance. In order to transport fuel to the start-up area precisely with a small supply of primary air, the nozzles were still put up with the nozzle oriented with the outlet downward, and this led to the fact that the entire nozzle had to be installed in a vertical position.

In order to ensure a stable combustion mode of the nozzle, it is sometimes necessary to fulfill conflicting requirements. Firstly, good mixing of fuel and air is required, and secondly, in the central region of the flame, in particular, during the starting phase, it is undesirable to have too high an air component and too much turbulence.

The objective of the invention is at least a partial solution to the described problems of the prior art and, in particular, to make possible start-up behavior that would be reliable, would not be accompanied by a significant emission, respectively smoke, in different positions of the installation.

This problem is solved by the features of an independent claim.

Preferred embodiments of the invention are given in the dependent claims.

The invention improves the nozzle of the initially considered kind due to the fact that the reflective disk in the axial direction has a given convexity, and that the convexity is provided in the direction of the burnout zone. Due to the convexity of the reflective disk, a certain temperature-independent formation of the reflective disk takes place. Reflective disks made in accordance with the prior art do not have this, and depending on the temperature, sudden changes in shape can occur that can adversely affect the combustion mode of the nozzle. Due to the bulge in the direction of the burnout zone, sufficient space is formed in the region of the launch chamber. It further turned out that the bulge in the direction of the burnout zone does not adversely affect the flow behavior in this zone. In particular, a pronounced vortex return region is retained in a burn-in region lying radially inside the region.

According to a preferred embodiment of the invention, it is provided that the outer circumference of the reflective disk defines a plane, and the ratio between the maximum axial distance of the reflective disk from this plane and the diameter of the reflective disk lies between 0.07 and 0.21. The farthest convex point of the reflective disk lies relative to the radial coordinate, preferably substantially in the center of the structure. From the plane, which is determined by the outer circumference of the reflective disk, this point is located at a distance that is determined by the reduced ratio.

In this regard, in particular, it is preferable that the ratio between the maximum axial distance of the reflective disk from the plane and the diameter of the reflective disk is about 0, 14. For example, the diameter of the reflective disk is about 40 mm, while the convexity is about 5.7 mm

According to a particularly preferred embodiment of the invention, a nozzle nozzle for supplying fuel and primary air is provided, a heat shield is provided between the nozzle nozzle and the combustion chamber, while the heat shield has openings for supplying secondary air to the combustion chamber, and these holes are provided with air guiding elements. In principle, a heat shield is necessary in order to protect the nozzle and fuel supply from thermal energy present in the combustion chamber. Further, secondary air is supplied through the heat shield to the combustion chamber. Due to the fact that the openings for supplying secondary air are provided with elements directing air, the supply of this secondary air can be carried out purposefully, so that it is possible to influence the combustion mode, both in relation to the starting mode, and the continuous operation mode.

It is advisable to provide that the elements directing the air were formed by tongues protruding in the direction of the combustion chamber and made integral with the heat shield. Such a heat shield can be made in the simplest way, for example, by forming tongues in a v-shaped stamp, which, after stamping or simultaneously with the stamping process, are folded out of the plane of the heat shield.

The invention has also been improved in that the tabs are formed at different angles to the surface of the heat shield and / or to the radius of the heat shield. If the tabs are directed almost perpendicular to the radius of the heat shield, then a stronger turbulence is created in this case, while with the tabs with a smaller angle to the radius, a slight turbulence is created. The tongues, which form a small angle with the surface of the heat shield, create air flows that have a large radial component and a small axial component, while with tongues with large angles to the surface of the heat shield, the axial component dominates. Thus, it becomes possible to direct secondary air into the central region of flame formation with a slight turbulence. In this way, on the one hand, the air necessary for combustion is supplied; however, there is no excessive turbulence that would adversely affect the stability of the flame. In particular, the distribution of the secondary air can be made depending on the directivity of the individual elements directing the air.

According to another embodiment, it is provided that the tongues are formed in groups of substantially equal angles to the surface of the heat shield and / or to the radius of the shield. Thanks to the collective orientation of the reeds, certain flow conditions in the combustion chamber are created.

Further, the invention is improved due to the fact that the nozzle has a burnout zone, and the secondary air supplied to the burnout zone has a stronger turbulence than the secondary air supplied to the launch zone. In the burnout zone, it is desirable to have a stronger turbulence. In particular, a radially inwardly lying, swirling return flow region improves burnup and ensures good utilization of the volume of the combustion chamber.

It is further provided that the heat shield has an opening for passing the flammable element.

According to a particularly preferred embodiment of the invention, it is further provided that the nozzle nozzle has a nozzle needle for supplying fuel to the nozzle and a primary air supply area for supplying combustion air to the nozzle, and by selecting the inner diameter of the nozzle needle, the fuel exit speed is set, and during starting the nozzle phase, the fuel, in substantially unsprayed form, enters the start-up zone. By reducing the inner diameter of the nozzle needle compared to the nozzle needles in heating devices in accordance with the prior art, at the same volumes of transported fuel, its exit speed increases. Due to this, at any installation position, it is possible to ensure that a jet of fuel enters from the outlet of the nozzle needle into the starting zone. In particular, with a small amount of primary air, and the supplied primary air should also have only a slight turbulence, the substantially un-sprayed fuel stream can reach the start zone. The result is a reliable start-up of the nozzle, and smoke generation during start-up is significantly reduced.

Preferably, the inner diameter of the nozzle needle is between 0.5 and 0.7 mm. Compared to the exit speeds of nozzle needles in accordance with the prior art, in which the inner diameter lies in the region of 0.8 mm, the exit speed for inner diameters between 0.5 and 0.7 mm can almost double or even more than double.

It is particularly preferred if the inner diameter of the nozzle needle is about 0.6 mm. With such an inner diameter in full load, i.e. with a mass fuel flow of 0.5 kg / h, exit speeds are possible above 0.6 m / s, while with an internal diameter of 0.8 mm, the exit speed lies in the region of 0.35 m / s. Correspondingly, the output speed increases under partial load, i.e. with a mass fuel flow of 0.2 kg / h from about 0.14 m / s to about 0.25 m / s. With an appropriate choice of design qualities or operating parameters, obtaining a substantially non-sprayed jet, which, when starting up the heating device, is directed to the starting zone, can also be achieved with existing nozzle needles with an inner diameter of about 0.8 mm.

It is advisable to provide that the launch zone was made in the form of a launch chamber, into which a flammable element protrudes. The wall of the combustion chamber can thus surround a flammable element. In this case, during the start-up mode, the “ballistic” fuel jet can wet the ignition element and the wall of the combustion chamber with fuel, so that the wall of the combustion chamber and adjacent structural elements after heating serve as a wall evaporator.

The basis of the invention is the knowledge that using the convex reflective disk of the proposed type, in particular in combination with the fuel supply of the proposed type and the heat shield of the proposed type, the operation mode of the nozzle can be significantly improved. This applies, in particular, to starting characteristics, stability of the combustion mode and possibilities regarding the installation position in a rail-mounted vehicle with a motor drive.

Below the invention is illustrated by reference to the attached drawings on the example of preferred embodiments. It is shown:

figure 1 - section of the nozzle according to the invention;

figure 2 is a perspective view of the nozzle flange with a heat shield installed thereon; and

figure 3 is a perspective view of a heat shield.

In the following description of preferred embodiments of the invention, the same reference numerals denote identical or comparable components.

Figure 1 shows a section of a nozzle according to the invention. The nozzle 10 according to the invention has a nozzle 12, which is rigidly connected to a heat shield 24. A heat shield 24, together with a pipe 40 of the combustion chamber connected to the heat shield 24, defines a combustion chamber 22. The pipe 40 of the combustion chamber is surrounded by an outer pipe 42, which forms the nozzle flange. A flame tube 38 is attached to this outer pipe 42. The joints between the heat shield 24 and the combustion chamber pipe 40 or between the combustion chamber pipe 40, the outer pipe 42 and the flame tube 38 are generally welded joints. On the fuel nozzle is a fuel supply 50, which has a metal pipe 52 for supplying fuel, as well as a nozzle needle 14 for injecting fuel into the combustion chamber 22. Further, in the region of the fuel nozzle 16, channels are provided for supplying primary combustion air to the fuel nozzle 12, which passes by the fuel needle 14, so that it can then go through the radially expanding air duct of the fuel nozzle 12 towards the combustion chamber and, finally, into the combustion chamber 22 itself. . Thanks to the radial expansion of the air duct, an improved atomization is achieved due to the Venturi effect. Inside the combustion chamber 22 is further located a reflective disk 36, which preferably has a bulge. This bulge in the direction of the burnout zone prevents sudden changes in the shape of the reflective disk 36 due to heat. Due to the bulge of the reflective disk 36 in the direction of the burnout zone 32, in addition, there is sufficient space to accommodate the launch chamber 18. The wall defining the launch chamber 18 is welded to the reflective disk 36.

FIG. 2 shows a perspective view of a nozzle flange with a heat shield installed thereon, and FIG. 3 shows a perspective view of a heat shield. Further, reference is also made to the components of the nozzle according to figure 1. The heat shield 24 has a central opening 48 through which the air-fuel mixture guided by the nozzle 12 enters the combustion chamber. Further, a side opening 34 is provided for passing the flammable element 20. On the heat shield 24, fastening pins 44, 46 are further provided to which the nozzle 12 is attached. Further, the heat shield 24 has a plurality of holes 26 through which secondary air can enter the combustion chamber 22. On the side of the heat shield 24 facing the combustion chamber 22, there are provided triangular shaped elements 28, 30 directing the air. Due to the different angles to the radius of the heat shield 24, they ensure the distribution of secondary air. The first group of air-guiding elements, partially indicated by 28, is directed at a large angle to the radius of the heat shield 24, i.e. has a substantially or almost tangential orientation. Due to this directivity, the secondary air passing through the corresponding openings 26, the direction of the outlet flows through which is indicated by an arrow, passes with a higher swirl past the reflective disk 36 into the burnout zone 32. This high-swirl air is directed to the region of the burnup zone 32 lying radially outside from the rear area of the combustion chamber 22, i.e. into the region of the combustion chamber 22, facing away from the heat shield 24, and then under a significant swirl back to the central region in the direction of the reflective disk 36. As a result, the gaseous components are successfully mixed in the burnout zone 32. Another group of air guide elements is directed at a slight angle to the radius of the heat shield 24. These air guide elements are partially indicated by 30. In addition, these air guide elements 30 have a smaller angle to the surface of the heat shield 24 than the elements 28 directing air. As a result of the passage through the air guiding elements 30, the direction of the outlet flows through which is shown by another arrow, this secondary air is supplied to the central region of the flame with a slight swirl, which, in particular, favors stable combustion behavior.

Thus, a spray nozzle according to the invention is proposed, which is improved with respect to the possible installation position, starting characteristics and continuous operation behavior. In addition, the problem is eliminated regarding temperature-related changes in the shape of the reflective disk.

Presented in the above description, in the drawings, as well as the features disclosed in the claims, both individually and in any combination, are essential for the implementation of the invention.

List of items

10 - Injector

12 - nozzle nozzle

14 - Nozzle needle

16 - Combustion air supply area

18 - Launch Area

20 - Flammable element

22 - Combustion chamber

24 - Heat shield

26 - Hole

28 - element directing air

30 - The element directing the air

32 - burnout area

34 - Hole

36 - Reflective Disk

38 - Heat pipe

40 - Combustion chamber pipe

42 - Outer pipe

44 - Fixing pin

46 - Fixing pin

48 - Hole

50 - Fuel supply

52 - Metal pipe

Claims (12)

1. A nozzle for a heating device, in particular for use in trackless vehicles with a motor drive, containing
a substantially symmetrical axis of combustion chamber (22) and
a reflective disk (36) located in the chamber (22),
characterized in that
the reflective disk (36) has a predetermined convexity in the axial direction, and
the bulge is provided in the direction of the burnout zone (32),
the outer circumference of the reflective disk defines a plane, and
the ratio between the maximum axial distance of the reflective disk from this plane and the diameter of the reflective disk lies between 0.07 and 0.21. 2. The nozzle according to claim 1, characterized in that the ratio between the maximum axial distance of the reflective disk (36) from the plane and the diameter of the reflective disk (36) is about 0.14. 3. The nozzle according to claim 1 or 2, characterized in that
a nozzle (12) for injecting fuel and primary air is provided,
a heat shield (24) is provided between the nozzle (12) of the nozzle and the combustion chamber (22), the heat shield having holes for supplying secondary air to the combustion chamber, and
the holes are equipped with elements (28, 30) directing the air. 4. The nozzle according to claim 3, characterized in that the air guiding elements (28, 30) are formed by tongues protruding in the direction of the combustion chamber (22), made integral with the heat shield (24). 5. The nozzle according to claim 4, characterized in that the tabs (28, 30) are formed at different angles to the surface of the heat shield (24) and / or to the radius of the heat shield. 6. The nozzle according to claim 4, characterized in that the tabs (28, 30) are formed in the form of groups with essentially the same angles to the surface of the heat shield (24) and / or to the radius of the heat shield. 7. The nozzle according to claim 3, characterized in that
the nozzle (10) has a start zone (18) and a burnout zone (32), and
the secondary air supplied to the burnout zone has a stronger turbulence than the secondary air supplied to the start-up zone. 8. Nozzle according to claim 3, characterized in that the heat shield (24) has an opening (34) for passing the ignition element (20). 9. The nozzle according to claim 3, characterized in that
the nozzle nozzle (12) has a nozzle needle (14) for supplying fuel to the nozzle (10) and a primary combustion air supply area to the nozzle, and
by selecting the inner diameter of the nozzle needle (14), the fuel exit speed is set so that during the start-up phase of the nozzle the fuel reaches the start zone (18) in a substantially un-sprayed form. 10. Nozzle according to claim 9, characterized in that the inner diameter of the needle (14) of the nozzle lies between 0.5 and 0.7 mm. 11. Nozzle according to claim 9 or 10, characterized in that the inner diameter of the needle (14) of the nozzle is about 0.6 mm. 12. The nozzle according to claim 7 or 8, characterized in that the launch zone (18) is made in the form of a launch chamber into which a flammable element (20) protrudes.

Images