CN110410822B - Centrifugal nozzle with variable nozzle opening area - Google Patents

Abstract

It is an object of the present invention to provide a variable throat area swirler with different nozzle exit areas at different oil pressures. The nozzle shell has an axial length, a first open end on an oil inlet side and a second open end on an oil outlet side are arranged on the axial length, a fuel oil cavity penetrates through the first open end and the second open end, a pipeline for feeding fuel oil is arranged on the shaft body in an outward protruding mode, and the fuel oil cavity is provided with an inner diameter gradually-expanding portion on the oil outlet side; the end cover is detachably connected with the first open end of the nozzle shell; the cylinder is movably arranged in the fuel oil cavity, a fuel oil channel for fuel oil to pass through is formed by a gap between the cylinder and the fuel oil cavity, one end of the cylinder is provided with an outer diameter gradually-expanding part and is opposite to the inner diameter gradually-expanding part, and the other end of the cylinder is opposite to and spaced from the end cover; the elastic piece is connected with the end cover and the column body; axial swirl vanes are provided in the fuel passage between the cylinder and the nozzle housing.

Description

Centrifugal nozzle with variable nozzle opening area

Technical Field

The invention relates to an engine combustion chamber, in particular to a fuel nozzle for the engine combustion chamber.

Background

The combustion of liquid fuel must be vaporized into oil gas, and then the combustion reaction is carried out in a gaseous state. Atomization and vaporization of liquid fuels are critical processes for gas turbine combustors, and atomization is the basis for vaporization. Fuel atomization for aircraft gas turbines is typically accomplished using fuel nozzles. The most widely used pressure type atomizing nozzle in aircraft gas turbines is the centrifugal nozzle at present. In the centrifugal nozzle, fuel oil is driven by oil pressure to pass through a swirl hole or a swirl groove in the nozzle, so that the fuel oil is sprayed out of a nozzle orifice in the form of a rotating liquid film. The liquid film is dispersed in a conical shape under the action of centrifugal force, so that the atomization cone angle of the outlet is increased, the interaction area with air is increased, and the atomization particle size is improved. However, for an aircraft engine, the variation of the oil supply flow under different working conditions is very different, and the requirement that the oil supply amount is changed by changing the oil supply pressure only through a simple single-oil-way nozzle is far from being met. For example, the maximum and minimum fuel supply to an engine often differ by more than a factor of 20, and the fuel supply pressure difference differs by a factor of 400.

The common solution is to overlap two nozzles on a nozzle and supply oil from two oil paths, which are generally called as primary and secondary oil paths. The fuel nozzles of the CFM56 series engine and the GE90 are double-oil-way centrifugal nozzles. Wherein, under the miniaturely, vice oil circuit is responsible for the fuel feeding, and along with fuel feeding pressure increase, vice oil circuit oil mass also increases gradually. When the oil pressure reaches a certain value, the main oil circuit starts to supply oil, and at the same time, the main oil circuit and the auxiliary oil circuit start to supply oil.

However, the inventors have recognized that, in the first place, the dual oil path centrifugal nozzle itself is more complicated in structure than the single oil path centrifugal nozzle, as shown in fig. 1. Fig. 1 shows the primary andsecondary oil jets 22, 24, the axial swirl vanes 26, 25 for generating swirl, and thehousings 21, 23. The complicated dual oil path structure makes the nozzle difficult to machine and heavy.

Meanwhile, according to the requirement of flow, the traditional engine combustion chamber double-oil-way centrifugal nozzle adopts a structure that a check valve (check valve) and a metering valve (metering valve) are combined. The specific method is that a check valve is arranged at the upstream of the auxiliary oil way, and whether the valve is opened or not is determined by oil pressure. The metering valve is arranged at the upstream of the main oil way, and fuel oil passes through the throttle valve with variable throttle area in the metering valve, so that main fuel oil and auxiliary fuel oil under different working conditions can obtain different distribution proportions under the condition of using the same fuel oil main pipe. For the double-oil-way centrifugal nozzle, in order to ensure that the oil quantity distribution proportion of the main oil way and the auxiliary oil way is different under different working conditions, an additional check valve and a metering valve need to be installed, and the difficulty of a control system and the weight of an engine are increased.

Disclosure of Invention

It is an object of the present invention to provide a variable throat area swirler with different nozzle exit areas at different oil pressures.

The centrifugal nozzle with the variable nozzle opening area comprises a nozzle shell, an end cover, a cylinder, an elastic piece and axial swirl vanes, wherein the nozzle shell has an axial length, a first open end on an oil inlet side and a second open end on an oil outlet side are arranged on the axial length, a fuel oil cavity penetrates through the first open end and the second open end, a pipeline for feeding fuel oil is arranged on a shaft body in a protruding mode, and the fuel oil cavity is provided with an inner diameter gradually expanding portion on the oil outlet side; the end cover is detachably connected with the first open end of the nozzle shell; the cylinder is movably arranged in the fuel oil cavity, a fuel oil channel for fuel oil to pass through is formed by a gap between the cylinder and the fuel oil cavity, one end of the cylinder is provided with an outer diameter gradually-expanding part and is opposite to the inner diameter gradually-expanding part, and the other end of the cylinder is opposite to and spaced from the end cover; the elastic piece is connected with the end cover and the column body; axial swirl vanes are provided in the fuel passage between the cylinder and the nozzle housing.

In one or more embodiments, the outer diameter gradually expanding part of the cylinder is a cone, and a generatrix of the cone is a concave curve.

In one or more embodiments, the internal diameter-diverging portion of the fuel chamber is linearly flared in longitudinal section.

In one or more embodiments, the tapered outer diameter portion of the post extends beyond the second open end of the nozzle housing.

In one or more embodiments, the fuel inlet conduit is angled with respect to an axis of the fuel chamber.

In one or more embodiments, the nozzle housing is cylindrical.

In one or more embodiments, the post is centrally located within the fuel cavity, with an annular gap formed between the post and the fuel cavity.

An extension spring and a cylinder structure are added in the nozzle, so that the area of the nozzle outlet is changed under the condition of different extension lengths of the spring, and the extension length of the spring is caused by the pressure of incoming fuel, thereby realizing the function of different nozzle outlet areas under different oil pressures.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a conventional dual oil path centrifugal nozzle;

FIG. 2 is a schematic diagram of a variable orifice area centrifugal jet configuration according to one or more embodiments.

Detailed Description

The following discloses many different embodiments or examples for implementing the subject technology described. Specific examples of components and arrangements are described below to simplify the present disclosure, but these are merely examples and do not limit the scope of the invention. For example, if a first feature is formed over or on a second feature described later in the specification, this may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact. Additionally, reference numerals and/or letters may be repeated among the various examples throughout this disclosure. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Further, when a first element is described as being coupled or coupled to a second element, the description includes embodiments in which the first and second elements are directly coupled or coupled to each other, as well as embodiments in which one or more additional intervening elements are added to indirectly couple or couple the first and second elements to each other.

In the embodiment shown in fig. 2, the variable throat area swirler includes a nozzle housing 11, anend cap 13, acylindrical body 16, anelastic member 14, andaxial swirler vanes 17. The nozzle housing 11 has an axial length with a first open end on the oil inlet side, on the left end in the drawing, and a second open end on the oil outlet side, on the right end in the drawing. The nozzle housing 11 further has afuel chamber 15 extending through the first open end and the second open end, and afuel inlet pipe 12 is provided to project outward from the shaft body, and thefuel chamber 15 has an inner diameter-enlargedportion 151 on the fuel outlet side. Theend cap 13 is removably attached to the first open end of the nozzle housing 11. Thecylinder 16 is movably disposed in thefuel chamber 15, and a gap between the cylinder and thefuel chamber 15 forms a fuel passage through which fuel passes, and has an outer diameter-gradually-enlargedportion 161 at one end thereof opposite to the inner diameter-gradually-enlargedportion 151 and at the other end thereof opposite to and spaced apart from thehead cover 13. Theelastic member 14 connects theend cap 13 and thecylinder 16.Axial swirl vanes 17 are arranged in the gap between thecylinder 16 and the nozzle housing 11.

In operation, fuel enters thefuel chamber 15 through theconduit 12 in the nozzle housing 11. As the fuel increases, after partially filling thefuel chamber 15, the fuel flows rightward through the fuel passage between the housing 11 and thecylinder 16, passes through theaxial swirl vanes 17, generates centrifugal force, and is finally ejected from the nozzle outlet between the housing 11 and thecylinder 16. As the fuel pressure increases and thefuel chamber 15 is completely filled, thecylinder 16 is subjected to fuel pressure and pulls theextension spring 14 to the right, at which time the nozzle outlet area between the housing 11 and thecylinder 16 increases gradually and fuel is ejected through the nozzle outlet of increased area. When the engine operating conditions change, for example when switching from take-off to cruise, the fuel volume decreases, the fuel pressure in thefuel chamber 15 decreases gradually, the pull force exerted by thespring 14 on thepost 16 pulls thepost 16 to the left, the nozzle area between the housing 11 and thepost 16 decreases gradually, and fuel is ejected through the nozzle outlet of reduced area.

In one or more embodiments, the taperedouter diameter portion 161 of thecylindrical body 16 is a cone, and the generatrix of the cone is a concave curve. The outlet area increases more rapidly than in the linearly diverging shape.

In one or more embodiments, the inner diameter-divergingportion 151 of thefuel chamber 15 is linearly flared in longitudinal section. It may also be a concave curve to increase the outlet area more rapidly.

As shown in fig. 1, the outer diameter-gradually-expandingportion 161 of thecylindrical body 16 partially protrudes from the second open end of the nozzle housing 11, i.e., the right end thereof. Thefuel inlet conduit 12 is angled with respect to the axis of thefuel chamber 15. The nozzle housing 11 is cylindrical, and may have another shape. Thepost 16 is located in the center of the fuel chamber and an annular gap is formed between thepost 16 and thefuel chamber 15.

In the previous embodiments, thespring 14 may also be adapted to act as a resilient member for a similar purpose. Because spring one end is connected inend cover 13 department, can dismantle to later stage washing, change nozzle internals.

In the foregoing embodiment, the resetting of thecolumn 16 is realized by the tension of the spring or the elastic member disposed between the end cover and the end of thecolumn 16, and compared with the embodiment by compressing the spring, the structure matching assembly of the baffle, the cavity and the like is simplified, and the configuration is simple.

In the foregoing embodiment, the axial swirl vanes are provided in the fuel passage, so that a centrifugal swirl effect of the fuel can be produced to cause the fuel to be ejected out of the nozzle opening in the form of a swirling liquid film. The liquid film is dispersed in a conical shape under the action of centrifugal force, so that the atomization cone angle of the outlet is increased, the interaction area with air is increased, and the atomization particle size is improved.

In the above embodiment, an extension spring and a column structure are added to the nozzle, so that the nozzle outlet area is changed under the condition of different extension lengths of the spring, and the extension length of the spring is caused by the pressure of the incoming fuel, thereby realizing the function of different nozzle outlet areas under different oil pressures. The function can solve the problem of complex structure of the double-oil-way centrifugal nozzle, the performance of the double-oil-way centrifugal nozzle is realized only by using a single oil way, and a check valve and a metering valve which are required by the double-oil-way centrifugal nozzle are not required to be additionally installed.

Although the present invention has been disclosed in terms of the preferred embodiment, it is not intended to limit the invention, and variations and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention. Therefore, any modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope defined by the claims of the present invention, unless the technical essence of the present invention departs from the content of the present invention.

Claims (7)

1. A variable throat area swirler comprising

The nozzle comprises a nozzle shell, a fuel oil cavity and a fuel oil inlet pipeline, wherein the nozzle shell has an axial length, a first open end on an oil inlet side and a second open end on an oil outlet side are arranged on the axial length, the fuel oil cavity penetrates through the first open end and the second open end, the fuel oil inlet pipeline is arranged on a shaft body in an outward protruding mode, and the fuel oil cavity is provided with an inner diameter gradually expanding part on the oil outlet side;

an end cap removably connected to the first open end of the nozzle housing;

the cylinder is movably arranged in the fuel oil cavity, a fuel oil channel for fuel oil to pass through is formed by a gap between the cylinder and the fuel oil cavity, one end of the cylinder is provided with an outer diameter gradually-expanding part and is opposite to the inner diameter gradually-expanding part, and the other end of the cylinder is opposite to and spaced from the end cover;

the elastic piece is connected with the end cover and the column body; and

and the axial swirl vanes are arranged in the fuel oil channel between the cylinder and the nozzle shell.

2. The swirler of claim 1, wherein the outer diameter tapered portion of the post is a cone, and a generatrix of the cone is concave.

3. A swirler as claimed in claim 2, wherein the internal diameter diverging portion of the fuel chamber is linearly flared in longitudinal cross-section.

4. The swirler of claim 1, wherein the outer diameter-diverging portion of the post extends beyond the second open end of the nozzle housing.

5. A swirler as claimed in claim 1 wherein the fuel inlet conduit is angled relative to the axis of the fuel chamber.

6. The swirler of claim 1, wherein the nozzle housing is cylindrical.

7. A swirler as claimed in claim 1, wherein the post is centrally located in the fuel chamber, an annular gap being formed between the post and the fuel chamber.

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