RU2298730C1 - Jet nozzle - Google Patents

Abstract

FIELD: combustion apparatus and combustion processes.

SUBSTANCE: jet nozzle comprises hollow tip that connects the space of one component with the combustion zone, e.g., the space of the combustion chamber, and bushing that embraces the tip with a spaced relation and connects the space of the other component with the combustion zone. The tip receives the inner pipe mounted with a spaced relation to the tip. The ring space between the inner pipe and tip is provided with longitudinal ribs that separate the ring space into the insulated passages. Some of the passages are connected with the space of fuel, and the others are connected with the space of oxidizer through openings made in the tip.

EFFECT: enhanced combustion efficiency.

3 dwg

Description

The invention relates to the field of power plants, and in particular to devices for mixing and atomizing fuel components, and can be used in the development of nozzles and mixing heads of liquid rocket engines (LRE).

One of the main problems in creating devices for mixing and atomizing components is to ensure the maximum possible completeness of combustion of the components, which is achieved by increasing the contact surface area of the components and reducing the characteristic transverse jet size of one of the components. In known nozzles, the fulfillment of these conditions leads to a significant complication of the design.

Known coaxial coaxial-jet nozzle containing a tip in the form of a hollow cylinder, connecting the cavity of the liquid oxidizer with the combustion zone (cavity of the combustion chamber), a sleeve with a cylindrical inner surface, covering the tip with a gap and connecting the cavity of the gaseous fuel with the combustion zone (B.E. Alemasov et al. “Theory of rocket engines”: Textbook for students of engineering specialties of universities, M., Mechanical Engineering, 1980, Fig. 18.2, pp. 225-226). In this nozzle, the oxidizing agent is fed into the combustion zone along the axial channel inside the tip, and the fuel through the annular gap between the sleeve and the tip. At the outlet of the nozzle, the oxidizer stream has the shape of a continuous cone, with its tip facing the nozzle tip, and the fuel stream has the shape of a hollow cone. The contact of fuel and oxidizer occurs on the surface of a continuous cone. Such a supply scheme does not provide a high-quality atomization of fuel components, which leads to a decrease in the coefficient of completeness of fuel combustion.

A known mixing head containing a housing in the form of a body of revolution with respect to the axis of symmetry, moreover, this housing is equipped with several injection elements with axes parallel to this common axis of symmetry and passing through the injector wall attached to this housing and separating this mixing head from the combustion unit, for connection with which this mixing head is designed, characterized in that each of the injection elements comprises a central injection channel adapted for communication the source of the second fuel component, and an annular injection gap surrounding this central channel and adapted to communicate with the source of the first fuel component, while an additional annular injection channel of the second fuel component is formed by the space existing around each injection element between its side surface and the injector partition, such so that the annular jet of the first fuel component flowing out of the annular gap is trapped between the central jet torogo fuel component and an outer annular stream of the second fuel component (RF patent 2129219, the application №94040159 / 06 of 02/11/94. French patent No. 9313056 from 03.11.93. MKI: F02K 9/00, F23R 3/00, F23D 14/62 - prototype).

In this mixing head, one of the components is fed through each nozzle in the form of a continuous annular jet. Inside and outside the annular jet, another component is supplied. This solution allows to increase the contact perimeter of the components, reduce the characteristic size of the oxidizer jet and significantly reduce the length of the non-decaying part of the jet.

The disadvantage of this solution is a significant increase in the radial size of the nozzle, which leads to a decrease in their number on the mixing head, and the insufficient completeness of the mixture formation provided by this nozzle.

The objective of the invention is to increase the completeness of combustion of the fuel components by increasing the contact area of the fuel components.

The problem is achieved in that in the proposed coaxial-jet nozzle containing a hollow tip connecting the cavity of one component with the combustion zone, for example, the cavity of the combustion chamber, a sleeve covering the tip with an annular gap and connecting the cavity of the other component with the combustion zone, according to the invention, inside the tip an inner tube is installed with an annular gap, and longitudinal ribs are made in the annular gap between the inner tube and the tip, dividing the annular gap into insulated analges, some of which are connected to the cavity of the fuel, others - through the holes in the tip - with the cavity of the oxidizer.

A comparative analysis of the claimed invention with the prototype and other known solutions in the art showed that the set of features described is unknown from the existing level of technology, on the basis of which we can conclude that the technical solution meets the criteria of the invention of "novelty".

When analyzing other well-known technical solutions in the art, the features that distinguish the claimed invention from the prototype were not identified, and the set of features set out should not be explicitly for a specialist from the existing level of technology, which allows us to conclude that the claimed technical solution meets the criteria of the invention "inventive level"

The compliance of the proposed technical solution with the criterion of "industrial applicability" follows from the following example of a specific embodiment of a coaxial-jet nozzle.

The advantages of the present invention will become apparent from the following detailed description of an example of its implementation, presented in the drawings, in which Fig. 1 shows an axial section of the proposed nozzle, in Fig. 2 - section AA - cross section of a coaxial-jet nozzle, in Fig. 3 - view along arrow B in figure 1.

The main elements of the proposed coaxial-jet nozzle are:

1 - hollow tip;

2 - annular gap;

3 - an internal tube;

4 - ribs;

5 - an isolated channel of an oxidizing agent;

6 - an isolated fuel channel;

7 - annular gap;

8 - sleeve;

9 - holes.

The proposed coaxial-jet nozzle comprises a hollow tip 1, inside of which an inner tube 3 with ribs 4 is installed with an annular gap 2, separating the annular gap 2 into insulated oxidant supply channels 5 and fuel supply channels 6. In the output part of the nozzle, a sleeve 8 is installed on the tip 1 with an annular gap 7, which connects the fuel cavity with the combustion zone. To feed the oxidizing agent into the channels 5 in the tip 1, holes 9 are made.

The proposed nozzle operates as follows.

One part of the fuel from the fuel cavity through the annular channel 7 between the tip 1 and the sleeve 8 is fed into the combustion zone.

Another part of the fuel enters the combustion zone through the internal cavity of the tube 3 and the isolated longitudinal channels 6.

The oxidizing agent is fed into the combustion zone from the oxidizer cavity through channels 5, into which, in turn, the oxidizing agent enters through openings 9. With such a supply of components, the isolated oxidizing jets are surrounded by continuous solid jets of fuel.

Changing the shape of the oxidizer jet from a continuous round to a hollow annular one, in the form of several isolated beams, improves the conditions for the destruction of the jet, reduces the characteristic transverse size of the jet of oxidizer, and increases the perimeter of the contact of the oxidizer with fuel. Thus, at the exit from the tip, the oxidizer jet is more prone to loss of its integrity and decomposes faster. The specified effect on the jet allows to improve the mixing conditions of the components in all modes, increase the specific thrust impulse by increasing the completeness of fuel combustion and reduce the possibility of unstable combustion.

Conducted analytical studies show that when using this technical solution, the contact perimeter of the components can be increased by about four times, which will significantly, several times, reduce the length of the non-disintegrated part of the liquid and the characteristic transverse size of the liquid stream, thereby increasing the efficiency of mixture formation.

Using the proposed technical solution will increase the specific thrust impulse, economy and ensure the stability of combustion in the combustion chamber at all engine operating modes.

Claims (1)

A coaxial jet nozzle containing a hollow tip connecting the cavity of one component with the combustion zone, for example, the cavity of the combustion chamber, a sleeve covering the tip with the annular gap and connecting the cavity of the other component with the combustion zone, characterized in that an inner tube is installed inside the tip with the annular gap and longitudinal ribs are made in the annular gap between the inner tube and the tip, dividing the annular gap into isolated channels, one of which is connected to the fuel cavity, through holes in the tip - with the cavity of the oxidizer.

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