CN110259604B - A needle plug injector - Google Patents

Abstract

The invention provides a needle-bolt injector, which comprises a needle-bolt sleeve and a needle-bolt rod. The needle-bolt sleeve and the needle-bolt rod are both rotatable structures; the needle-bolt rod is axially provided with a propellant supply pipe The inner flow channel is connected with the inner flow channel, and the position near the end of the needle bolt rod is provided with an inner flow channel spray hole that communicates with the inner flow channel; the needle bolt sleeve is coaxially sleeved on the needle bolt rod and surrounded by the needle bolt rod. An outer flow channel with annular structure, the outer flow channel forms an annular structure outer flow channel spray ring at one end near the nozzle hole of the inner flow channel; a communication hole is provided on the side of the needle plug sleeve for connecting the outer flow channel with the propellant supply pipe The connecting hole is tangent to the outer flow channel. The communication hole and the outer flow channel are set tangentially into a tangential structure, so that the propellant ejected from the outer flow channel has a certain radial velocity after being ejected under the action of centrifugal acceleration, which effectively expands the radial direction of the spray. range; a gas channel is provided upstream of the outer channel to assist in the atomization of the liquid propellant. The invention is applied to the field of space propulsion technology.

Description

A needle plug injector

technical field

The invention relates to the technical field of space propulsion, in particular to a needle plug injector.

Background technique

The working process of a liquid rocket engine includes injection, atomization, evaporation, chemical reaction and other main processes. Among them, the injector determines the speed, distribution and atomization performance of the propellant entering the combustion chamber, so it has an important impact on the performance of the engine. Needle-bolt injector engines usually use only one needle-bolt nozzle. Compared with traditional engines, it usually requires dozens or hundreds of injection units. It has the advantages of simple structure, depth adjustment ability, and internal combustion stability. It is expected to be widely used in liquid rockets. Engines, especially variable thrust liquid rocket engines. Needle plug injectors usually include a needle plug and an injector base, and are generally divided into two categories: radial slot type and radial hole type. Of these, the latter is widely used due to better mixing properties. But the shortcomings of the needle plug injector in the prior art are also relatively obvious, such as: (1) the entrance of the needle plug sleeve is a straight hole, and the speed of the propellant flows down basically against the wall after flowing out through the annular seam, which cannot effectively expand the spray Distribution range; (2) Both propellants are liquid, and the atomization is achieved only by the collision between the liquids. The atomization effect is greatly affected by the structure design of the injector and the size of the mixing ratio.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the purpose of the present invention is to provide a needle plug injector, which has the characteristics of uniform injection, good atomization effect, and wide spray range.

The technical solutions it adopts are:

A needle-bolt injector, comprising a needle-bolt sleeve and a needle-bolt rod, wherein the needle-bolt sleeve and the needle-bolt rod are both gyratory structures;

An inner flow channel that can communicate with the propellant supply pipeline is arranged in the needle bolt rod along the axial direction, and an inner flow channel nozzle hole communicated with the inner flow channel is arranged on the needle bolt rod at a position close to the end;

The needle bolt sleeve is coaxially sleeved on the needle bolt rod and forms an outer flow channel with an annular structure with the needle bolt rod. ring;

A communication hole is provided on the side part of the needle plug sleeve for connecting the outer flow channel and the propellant supply pipeline, and the communication hole is tangent to the outer flow channel.

As a further improvement of the above technical solution, the side part of the needle bolt sleeve is also provided with an air injection hole for passing the atomization auxiliary gas into the outer flow channel, and the communication hole is located between the air injection hole and the outer flow channel spray ring.

As a further improvement of the above technical solution, the number of the nozzle holes in the inner flow channel is multiple and distributed on the side wall of the needle bolt rod in a multi-layer annular structure.

As a further improvement of the above technical solution, the diameter of the nozzle holes in the inner flow channel is 0.3 mm to 2.0 mm.

As a further improvement of the above technical solution, the thickness of the flow channel of the outer flow channel spray ring is 0.3 mm to 0.8 mm.

As a further improvement of the above technical solution, a support member with an annular structure is provided on the side wall of the needle bolt rod, the inner wall of the needle bolt sleeve is in contact with the outer wall of the support member, and the support member is in contact with the needle bolt sleeve and the support member. When the needle bolt rod is used, the outer flow channel is divided into a mixing cavity and an air intake cavity, the mixing cavity is communicated with the communication hole, the air intake cavity is communicated with the air injection hole, and there are several annular spaces on the support member that can communicate with the mixing cavity and the air inlet. The communication groove of the intake chamber.

Beneficial technical effects of the present invention:

The present invention improves the design of the structure of the needle plug injector. By setting the communication hole of the outer flow channel and the supply pipeline into a tangential structure, the propellant ejected from the outer flow channel is under the action of centrifugal acceleration. After spraying, it has a certain radial velocity, which effectively expands the radial range of the spray.

Description of drawings

Fig. 1 is the sectional view of the needle plug injector of the present embodiment;

FIG. 2 is a schematic cross-sectional structure diagram of a communication hole tangent to an outer flow channel in this embodiment;

Fig. 3 is an axonometric view of the needle bolt rod of the present embodiment;

Figure 4 is an axonometric view of the pintle sleeve in this embodiment.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present invention will be further described in detail below with reference to the specific embodiments and the accompanying drawings. It should be noted that, in the drawings or descriptions of the specification, undescribed contents and some English abbreviations are contents well known to those of ordinary skill in the art. Some specific parameters given in this embodiment are only exemplary, and the values can be changed to appropriate values accordingly in different implementations.

The needle-bolt injector as shown in Figures 1-3 includes a needle-bolt sleeve 1 and a needle-bolt rod 2. Both the needle-bolt sleeve 1 and the needle-bolt rod 2 are of revolving body structures; There is an inner flow channel 21 that can be communicated with the propellant supply pipeline, and the position close to the end of the needle bolt rod 2 is provided with an inner flow channel nozzle 22 that communicates with the inner flow channel 21; the needle bolt sleeve 1 is coaxially sleeved The outer flow channel 3 is arranged on the needle bolt rod 2 and forms an annular structure with the needle bolt rod 2, wherein, coaxial refers to the coincidence of the rotation axis of the needle bolt sleeve 1 and the needle bolt rod 2; the outer flow channel 3 is facing An outer flow channel spray ring 31 of annular structure is formed at one end of the inner flow channel nozzle hole 22, that is, the annular seam between the needle bolt sleeve 1 and the needle bolt rod 2; one end of the needle bolt sleeve 1 passes through the needle bolt rod 2 The threads 23 are fixedly connected, and the top of the outer flow channel 3 is sealed by means of a gasket; The hole 11 is used to communicate the outer flow channel 3 and the propellant supply pipeline. Referring to FIG. Referring to FIG. 4 , the number of communication holes 11 is multiple and uniformly distributed on the side of the needle plug sleeve 1 in the circumferential direction, so that the propellant can enter the outer flow channel 3 uniformly along the plurality of communication holes 11 .

In this embodiment, an inner flow channel 21 is arranged inside the needle bolt rod 2, and an outer flow channel 3 is formed by the needle bolt sleeve 1 and the needle bolt rod 2, forming a structure in which the outer flow channel 3 surrounds the inner flow channel 21, and at the same time, the communication The hole 11 is tangent to the outer flow channel 3 and is arranged in a tangential structure, so that the propellant ejected from the outer flow channel 3 has a certain radial velocity after being ejected under the action of centrifugal acceleration, which effectively expands the diameter of the spray. distribution range.

The end of the needle bolt sleeve 1 is provided with an annular skirt 12 extending radially inward, and the outer flow channel spray ring 31 is located between the annular skirt 12 and the outer wall of the needle bolt rod 2. In this embodiment, the outer flow channel spray ring 31 has a The thickness of the flow channel is 0.3mm-0.8mm, that is, the distance between the annular skirt 12 and the outer wall of the needle bolt rod 2 is 0.3mm-0.8mm. There is also an air injection hole 13 on the side of the needle bolt sleeve 1 for passing atomization auxiliary gas into the outer flow channel 3 , and the communication hole 11 is located between the air injection hole 13 and the outer flow channel spray ring 31 . By arranging a gas inlet above the propellant, gas is introduced into the outer flow channel 3 through the injection hole 13 during the injection process of the needle plug injector, thereby promoting the atomization of the liquid propellant in the outer flow channel 3. Combined with the needle plug spray The function of the injector and the bubble atomizing sprayer can effectively improve the disadvantage that some liquid film propellants cannot be directly collided with the jet propellant and broken. The liquid film propellant is the propellant ejected from the spray ring 31 of the outer flow channel, and the jet propellant is the propellant ejected from the nozzle hole 22 of the inner flow channel. Referring to FIG. 4 , the number of air injection holes 13 is multiple and uniformly distributed on the side of the needle plug sleeve 1 along the circumferential direction, so that the atomization auxiliary gas can enter the outer flow channel 3 evenly along the plurality of air injection holes 13 .

The number of the nozzle holes 22 in the inner flow channel is multiple and uniformly distributed on the side wall of the needle bolt rod 2 along the circumferential direction. In this embodiment, the plurality of inner flow channel nozzle holes 22 are distributed on the side wall of the needle bolt rod 2 near the end in two layers, one up and one down. In this embodiment, the diameter of the inner flow channel nozzle holes 22 is 0.3 mm to 2.0 mm, and the number of the inner flow channel nozzle holes 22 needs to be based on the diameter of the inner flow channel nozzle holes 22 and the flow rate, flow rate and empirical flow coefficient of the propellant. to calculate and determine, which is not repeated in this embodiment.

A support member 24 with an annular structure is arranged on the side wall of the needle bolt rod 2. The support member 24 is integrally formed with the needle bolt rod 2. The inner wall of the needle bolt sleeve 1 is attached to the outer wall of the support member 24 to ensure that the needle bolt sleeve 1 is connected to the needle bolt shaft 2. The bolts 2 are concentric, ie radially positioned. The support member 24 divides the outer flow channel 3 into a mixing chamber and an air inlet chamber while supporting the needle bolt sleeve 1 and the needle bolt rod 2. The mixing chamber is communicated with the communication hole 11, and the air inlet chamber is communicated with the air injection hole 13. The support member 24 The upper annular space is provided with a plurality of communication grooves 25 which can communicate with the mixing chamber and the air intake chamber.

The needle plug injector in this embodiment is mainly applied to the combination of liquid-liquid propellants, and its working process is as follows: two kinds of propellants flow out from the supply pipeline respectively. The first propellant flows directly down the inner flow channel 21 on the needle bolt rod 2, and then flows out from the two rows of inner flow channel nozzle holes 22 in the form of jets; the second propellant flows in through the tangential communication holes 11 The mixing cavity of the outer flow channel 3 finally flows out from the outer flow channel spray ring 31 in the form of a liquid film. At the same time, this configuration combines the advantages of the needle plug injector and the bubble atomizing injector, and also adds atomizing auxiliary gas upstream of the second propellant, and the atomizing auxiliary gas enters the outer flow channel 3 from the air injection hole 13 After the air inlet cavity, it flows downward, flows downward through the communication groove 25 and joins the mixing cavity together with the second propellant. The atomization auxiliary gas can effectively promote the atomization of the liquid propellant.

The description of the preferred embodiments of the present invention is included above, which is for the purpose of describing the technical features of the present invention in detail, and is not intended to limit the content of the invention to the specific form described in the embodiments, and other modifications and Variations are also protected by this patent. The gist of the present disclosure is defined by the claims, rather than by the detailed description of the embodiments.

Claims (4)

1. The pintle injector is characterized by comprising a pintle sleeve and a pintle rod, wherein the pintle sleeve and the pintle rod are of a rotary body structure;

an inner flow channel capable of being communicated with a propellant supply pipeline is axially arranged in the pin rod, and an inner flow channel spray hole communicated with the inner flow channel is formed in the pin rod and is close to the end part;

the pintle sleeve is coaxially sleeved on the pintle rod and forms an outer flow passage with an annular structure with the pintle rod, and the outer flow passage forms an outer flow passage spraying ring with an annular structure at one end close to the spraying hole of the inner flow passage;

the side part of the pintle sleeve is provided with a communication hole for communicating the outer flow channel with a propellant supply pipeline, and the communication hole is tangent to the outer flow channel;

the inner runner spray hole is positioned below the outer runner spray ring, so that the radial jet flow propellant sprayed from the inner runner spray hole and the axial rotating liquid film propellant sprayed from the outer runner spray ring can collide externally, the spray range is effectively expanded compared with the collision of a direct-current annular liquid film and jet flow, the collision position of the propellant is properly pulled away from the outer wall surface of the pintle rod, and the spray effect is further improved.

2. The pintle injector of claim 1, wherein an air injection hole is further formed in a side portion of the pintle sleeve for introducing the atomizing auxiliary gas into the outer flow passage, and the communication hole is located between the air injection hole and the outer flow passage injection ring.

3. The pintle injector of claim 1 or 2, wherein the number of the inner runner nozzles is plural and is distributed on the sidewall of the pintle shaft in a multilayer annular structure.

4. The pintle injector according to claim 1 or 2, wherein a support member of an annular structure is arranged on the side wall of the pintle shaft, the inner wall of the pintle sleeve is attached to the outer wall of the support member, the support member divides the outer flow passage into a mixing chamber and an air inlet chamber when supporting the pintle sleeve and the pintle shaft, the mixing chamber is communicated with the communication hole, the air inlet chamber is communicated with the air injection hole, and a plurality of communication grooves capable of communicating the mixing chamber and the air inlet chamber are arranged on the support member at annular intervals.

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