Patent ID: 12234989

Wherein,1—oil pipeline,2—outer housing,3—front-end swirling part,31—first shutter,32—boss,33—secondary swirler,4—outer interstage section,41—circular housing,42—main stage swirler,43—oil guiding flange,44—oil guiding hole,45—self-excited sweeping oscillating fuel injection nozzle,451—contracted opening,452—oscillating chamber,453—spout,454—blocking body,455—fuel backflow part,5—inner interstage section,6—pilot stage fuel injection device,61—pilot stage fuel injection nozzle,62—positioning face,63—central swirler,64—guiding body,65—fuel injection nozzle mounting ring,7—second shutter,81—fuel passage,91—first incoming flow,92—second incoming flow,93—third incoming flow.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. It can be understood that the embodiments described here are only used to illustrate relative contents rather than limiting the scope of the present disclosure. In addition, it should also be noted that, only the parts related to the present disclosure are shown in the drawings for the convenience of description.

It should be noted that the embodiments of the present disclosure and the features of the embodiments may be combined with each other if there is no conflict. The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with the embodiments.

Referring toFIG.2andFIG.3, the present disclosure provides a central staged combustion chamber with self-excited sweeping oscillating fuel injection nozzles45. In terms of functions, the central staged combustion chamber mainly includes an oil pipeline1, an outer housing2, a main stage and a pilot stage. In terms of specific structures, the main stage includes an outer interstage section4, an inner interstage section5and a second shutter7; and the pilot stage includes a front-end swirling part3and a pilot stage fuel injection device6. As can be seen fromFIG.3, the outer housing2, the front-end swirling part3, the outer interstage section4, the inner interstage section5, the pilot stage fuel injection device6and the second shutter7are nested in sequence or connected to form the central staged combustion chamber inFIG.2.

Firstly, the solutions of the present disclosure are explained in terms of functional partitioning. Referring toFIG.4, the outer housing2presents a sleeve shape with a penetrating cavity inside. Preferably, the outer housing2is rotationally symmetrical with its central axis. A diameter of the outer housing2in a direction of facing a direction of an incoming flow is larger than a diameter of the outer housing2in a direction of facing away from the direction of the incoming flow, so that the outer housing2can improve the flow speed of the incoming flow to a certain extent.

The main stage and the pilot stage are coaxial with the outer housing2, that is, the main stage and the pilot stage are coaxial with the central axis. A diameter of a main body of the main stage is smaller than an inner diameter of the outer housing2, so that a primary swirling passage is defined between the surface of the main body of the main stage and an inner wall surface of the outer housing2. The main stage also includes a main stage swirler42suitable for being disposed in the primary swirling passage. Referring toFIG.12, a first incoming flow91is capable of rotating in a first direction after passing through the main stage swirler42.

Referring toFIG.5, an annular fuel passage81is also disposed inside the main body of the main stage. Specifically, the inner wall and an outer wall of the main body are disposed at intervals to form a sandwich structure, and a space in the middle part is the fuel passage81. A plurality of self-excited sweeping oscillating fuel injection nozzles45are disposed on the side of the main body in the direction facing away from the direction of the incoming flow. Preferably, the plurality of self-excited sweeping oscillating fuel injection nozzles45are uniformly disposed along a circumferential direction of the axis. One end of the fuel passage81should be connected with the oil pipeline1, and the other end should be connected with the plurality of self-excited sweeping oscillating fuel injection nozzles45. Therefore, after entering the fuel passage81, the liquid fuel in the oil pipeline1quickly fills the whole passage along the annular fuel passage81, and uniformly enters the self-excited sweeping oscillating fuel injection nozzles45from a connection between the fuel passage81with the self-excited sweeping oscillating fuel injection nozzles45.

The self-excited sweeping oscillating fuel injection nozzles45are suitable for injecting oscillating liquid fuel into the primary swirling passage. The high-speed swirling flow generated at the rear of the main stage swirler42can quickly disperse the liquid fuel after encountering the fan-shaped liquid fuel generated by the self-excited sweeping oscillating fuel injection nozzles45. In order to further mix the liquid fuel and gas, the pilot stage usually includes a swirler that rotates the incoming flow, so that the liquid fuel and the gas of the incoming flow can be further mixed.

Referring toFIG.12, the pilot stage includes a secondary swirler33and a central swirler63. A second incoming flow92rotates in a second direction after entering the secondary swirler33. A third incoming flow93rotates in a third direction after entering the central swirler63. When the second direction and the third direction are opposite, air can be further mixed with the liquid fuel of the pilot stage.

Referring toFIG.9, each of the self-excited sweeping oscillating fuel injection nozzles45includes a contracted opening451, an oscillating chamber452and a spout453. The contracted opening451is communicated with the fuel passage81through an oil guiding hole44, and the fuel enters the self-excited sweeping oscillating fuel injection nozzle45from the oil guiding hole44, and accelerates into the oscillating chamber452after passing through the contracted opening451. The contracted opening451is connected with one end of the oscillating chamber452, and the spout453is connected with the other end of the oscillating chamber452.

Two blocking bodies454are symmetrically disposed in the oscillating chamber452with a line connecting a central point of the contracted opening451and a central point of the spout453as an axis of symmetry, and the two blocking bodies454separate the oscillating chamber452into a fuel oscillating part located in the middle part and two fuel backflow parts455distributed on both sides. The fuel backflow parts455form a feedback channel. Each of the blocking bodies454presents an “L” shape, and two right-angled sides of the blocking body454and two side walls of the oscillating chamber452form the fuel backflow part455. A bottom edge of the “L” shape is close to the contracted opening451. When passing through the blocking body454, the fuel diffuses towards a vertical edge of the blocking body454and forms a vortex. Vortices on both sides are difficult to be exactly the same, therefore, there must be a vortex with relatively strong rotation, causing a main fuel to deflect to one side of the vortex with relatively strong rotation, and further strengthening the strength of the vortex on the side, while weakening the strength of the vortex on the other side. Meanwhile, since the main fuel flows close to one side, a pressure at an outlet of the fuel backflow part455near the side is relatively low. When the main fuel passes through an inlet of the fuel backflow part455, more liquid fuel flows from the inlet of the fuel backflow part455to the outlet of the fuel backflow part455due to a pressure difference, the pressure of the outlet is compensated to push the main fuel at the outlet away from the vortex. When the main fuel deflects to the other side by a large angle, the vortex on the other side has an advantage in rotational strength, so that the main fuel is quickly attracted and deflected to the other side. By repeating the above processes, high-frequency oscillating jets are output at the spout453.

The spout453is connected with the oscillating chamber452through a throat hole. Specifically, by setting the throat hole, the fluid diffused in the oscillating chamber452can be contracted. Since the main fluid has deviated in the oscillating chamber452, the jet emitted from the throat hole will continue the direction of the main fluid in the oscillating chamber452. An outer end of the spout453is larger than a connecting end connecting the spout453with the throat hole, specifically, a trumpet-shaped opening is formed. Consistent with the spout453, the trumpet-shaped opening can increase a space applied for the airflow to swing.

Generally, the uniformity of fuel and air mixing will determine the adequacy and quality of combustion. The self-excited sweeping oscillating fuel injection nozzles45can spread the fuel in a large space and evenly mix it with the air under the action of the high-speed transverse airflow, thereby effectively improve the combustion efficiency. The use of direct fuel atomization leads to a low fuel injection efficiency (FIG.10A), and the use of sweeping fuel injection usually requires to introduce a mechanical control structure or an electromagnetic control mechanism, which increases the complexity of the engine. The present disclosure creatively introduces a self-excited sweeping oscillating fuel injection nozzle45with a self-excited sweeping-type oscillation. Under the injection of high-pressure liquid fuel, the self-excited oscillation chamber is used to generate high-frequency sweeping-type oscillating liquid fuel output (FIG.10B), such that mechanical kinematic structures or electromagnetic structures are not needed.

Referring toFIG.3, in order to facilitate machining and assembly, the main stage also includes an outer interstage section4, an inner interstage section5and a second shutter7, and the pilot stage also includes a front-end swirling part3and a pilot stage fuel injection device6.

Referring toFIG.7andFIG.8, the outer interstage section4includes a circular housing41, the a main stage swirler42disposed on an outer side of the circular housing41, and an oil guiding flange43disposed at one end of the circular housing41and extending to an axis of the circular housing41. Since the above structure is relatively simple, the structural member can be obtained directly by casting and machining. Meanwhile, in the direction of the oil guiding flange43away from the incoming flow, the self-excited sweeping oscillating fuel injection nozzle45can be directly machined on the surface according to the shape by milling, and the self-excited sweeping oscillating fuel injection nozzle45presents a groove. Oil guiding holes44corresponding to the number of self-excited sweeping oscillating fuel injection nozzles45are formed at the ends of the self-excited sweeping oscillating fuel injection nozzles45by a drilling machine.

Referring toFIG.3, the purpose of the inner interstage section5is to form the inner wall surface of the main stage, which does not need other auxiliary functional structures, thereby having a regular and cylindrical main structure. A maximum outer diameter of the inner interstage section5is smaller than an inner diameter of the circular housing41, and an end of the inner interstage section5is suitable for abutting with the oil guiding flange43, thereby forming a circular-ring-shaped fuel passage81communicated with the plurality of oil guiding holes44.

Further, a longitudinal direction of the self-excited sweeping oscillating fuel injection nozzle45is radially distributed along the oil guiding flange43, and the oil guiding hole44need to be disposed at the end of the self-excited sweeping oscillating fuel injection nozzle45. In order to ensure the rapid distribution of liquid fuel, a diameter of a main body of the inner interstage section5is larger than a diameter of a contact part between the inner interstage section5and the oil guiding flange43, thereby forming a step shape.

Referring toFIG.6, the front-end swirling part3includes the first shutter31, a boss32located on a surface of the first shutter31and facing the direction of the incoming flow, and a secondary swirler33located on a surface of the boss32and facing the direction of the incoming flow. Referring toFIG.5, the first shutter31is suitable for closing an opening of the groove facing away from the direction of the incoming flow, so that the liquid fuel can only enter the self-excited sweeping oscillating fuel injection nozzle45through the oil guiding hole44and be ejected from the spout453of the self-excited sweeping oscillating fuel injection nozzle45.

It is worth noting that the first shutter31, the boss32and the secondary swirler33are all circular-ring-shaped channels. The middle part of the circular-ring-shaped channels is an accommodating structure, so that the airflow of the secondary swirler33and the central swirler63can pass smoothly. The secondary swirler33is machined by a milling machine to form a helical tooth structure, thereby guiding the direction of airflow rotation.

Referring toFIG.11, the pilot stage fuel injection device6includes a positioning face62used for abutting with the secondary swirler33, a central swirler63disposed on a side of the positioning face62away from the secondary swirler33, a pilot stage fuel injection nozzle61located on the side of the central swirler63facing the direction of the flow direction, and a guiding body64. Specifically, the pilot stage fuel injection nozzle61is connected with the central swirler63through a fuel injection nozzle mounting ring65. The pilot stage fuel injection nozzle61is connected with another oil pipeline in the direction facing the direction of the incoming flow, and the liquid fuel is injected into the middle part of the central swirler63through a middle through hole of the pilot stage fuel injection nozzle61. The liquid fuel injected by the pilot stage fuel injection nozzle61will be fully dispersed and mixed when encountering the rotating airflow output by the central swirler63.

The central swirler63and the guiding body64are located on two sides of the positioning face62. The central swirler63, the positioning face62and the guiding body64are all circular-ring-shaped structures. The helical tooth structure on the central swirler63is obtained by milling. The incoming flow converges towards the center of the central swirler63after passing through the central swirler63, and flows to the end of the central staged combustion chamber through the guiding body64. The guiding body64can first separate rotating airflows generated by the secondary swirler33and the central swirler63, when the two rotating airflows rotate stably and then collide and mix together, the mixing degree of liquid fuel and air is further improved.

Referring toFIG.3, the second shutter7is provided with a notch suitable for being connected with the oil pipeline1, and the liquid fuel of the oil pipeline1is suitable for entering the fuel passage81through the notch. The oil pipeline1communicates with the fuel passage81of the main stage through a joint.

In the present disclosure, the fuel is output in a fan shape through each of the self-excited sweeping oscillating fuel injection nozzles45and is dispersed by an incoming flow through the swirling passage, so that the atomization performance and spatial distribution uniformity of the fuel can be greatly improved. Meanwhile, since the self-excited sweeping oscillating fuel injection nozzles45suitable for outputting the oscillating liquid fuel need to have a complex cavity structure, if the original oil circuit is adopted, the structural complexity of the central staged combustion chamber will be increased inevitably. In the present disclosure, from the point of view of manufacturing, components of the central staged combustion chamber are decomposed into a plurality of modules which are easy to process, so that the fuel passage81can be connected with the oil pipeline1and communicated with the self-excited sweeping oscillating fuel injection nozzles45, without increasing the complexity of the system. Compared with the existing central staged combustion chamber, the central staged combustion chamber of the present disclosure also has the characteristics of compact structure and miniaturization.

In the description of this specification, the description with reference to the terms such as “one embodiment/mode”, “some embodiments/mode”, “example”, “specific example”, or “some examples” means that specific features, structures, materials or characteristics described in connection with the embodiment/mode or example are included in at least one embodiment/mode of the present disclosure. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment/mode or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments/modes or examples in a suitable way. In addition, those skilled in the art can combine or integrate different embodiments/modes or examples described in this specification and the features of different embodiments/modes or examples if there is no conflict.

In addition, the terms “first” and “second” are only used for descriptive purposes, and should not be considered as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with “first”, “second” may expressly or implicitly include at least one of those features. In the description of the present disclosure, “plurality” means at least two, such as two, three, unless expressly and specifically defined otherwise.

Those skilled in the art should understand that the above embodiments are only for clearly illustrating the present disclosure, rather than limiting the scope of the present disclosure. For those skilled in the art, other changes or modifications may also be made on the basis of the above disclosure, and these changes or modifications are still within the scope of the present disclosure.