阅读说明：本技术 一种螺旋排列喷嘴的超声速气体引射器 (Supersonic gas ejector with spirally arranged nozzles ) 是由 赵宏 朱昊伟 戴芳立 于 2019-11-29 设计创作，主要内容包括：一种螺旋排列喷嘴的超声速气体引射器,其特征在于引射器由混合室(1)、引射气集气室(2)、超声速引射喷嘴阵列(3)、进气室(4)、扩压器(5)组成。超声速引射喷嘴阵列(3)在混合室(1)的锥形筒壁面上沿多头螺旋线分布,进而增加引射流与被引射流的接触面积,逐步改变混合室内流向压力梯度,达到缩短掺混距离,提高混合效率,提升引射器性能的目的。(The supersonic gas ejector with spirally arranged nozzles is characterized by comprising a mixing chamber (1), an ejection gas collection chamber (2), a supersonic ejection nozzle array (3), an air inlet chamber (4) and a diffuser (5). The supersonic velocity draws and penetrates nozzle array (3) and distribute along the bull helix on the toper section of thick bamboo wall of mixing chamber (1), and then increase and draw and penetrate the area of contact who flows and be drawn and penetrate the flow, gradually change the indoor flow direction pressure gradient of mixing, reach and shorten the mixing distance, improve mixing efficiency, promote the purpose of ejector performance.)

1. The utility model provides a supersonic velocity gas ejector of spiral arrangement nozzle, its characterized in that ejector comprises mixing chamber (1), draws gas collection chamber (2), supersonic velocity and draws nozzle array (3), inlet chamber (4), diffuser (5), inlet chamber (4), mixing chamber (1), diffuser (5) are connected along axial sequence, supersonic velocity draws nozzle array (3) to install on mixing chamber (1) wall, draw gas collection chamber (2) and mixing chamber (1) coaxial sealing connection.

2. The supersonic gas ejector with spirally arranged nozzles as claimed in claim 1, wherein: the area of a single nozzle outlet of the supersonic velocity injection nozzle array (3) is 1-5% of the area of an outlet of the mixing chamber (1), and the Mach number of the single nozzle outlet is 1.5-4.0.

3. The supersonic gas ejector with spirally arranged nozzles as claimed in claim 1, wherein: the mixing chamber (1) is composed of a conical cylinder and a cylinder.

4. The supersonic gas ejector with spirally arranged nozzles as claimed in claim 1, wherein: the side surface of the conical cylinder of the mixing chamber (1) is provided with an array of mounting holes which are arranged according to a multi-head spiral line with a lead angle of 1-5 degrees, the axial distance of the adjacent mounting holes on each spiral line of each spiral line is about 20-40mm, the distance along the spiral line direction is 60-120mm, and the included angle between the axis of each mounting hole and the axis of the mixing chamber (1) is 5-10 degrees.

Technical Field

The invention relates to a device for obtaining vacuum and conveying fluid by taking gas as an injection working medium, belonging to the field of aerodynamics.

Background

The supersonic gas ejector is a fluid conveying device, which sucks another low-pressure fluid by means of high-speed flow formed after high-pressure gas (steam) flows through a supersonic nozzle, and performs energy exchange and substance mixing in the device to achieve the purpose of extracting vacuum or conveying the low-pressure fluid. The supersonic gas ejector only consumes the energy of the ejection gas without external power, has simple structure, easy manufacture and convenient connection with a pipeline, and certain gas (such as steam) can be condensed and recovered in subsequent equipment for recycling, so the supersonic gas ejector is widely applied to the field of vacuum environment acquisition.

At present, the conventional Laval nozzle is mostly adopted for realizing gas supersonic flow in the supersonic gas ejector, and the ejection and suction effects are close to the upper limit. CN105179328A discloses a dynamic self-adjusting steam jet pump, adopts porous fixed plate and adjusting piston to combine together to adapt to the influence that work steam pressure fluctuation brought, guarantees the stable operation ability of jet pump under the variable operating mode condition, but can not improve jet pump injection coefficient k under the rated operating mode. The steam jet pump disclosed in CN202946460U adopts a spherical suction chamber, which simplifies the structure of the jet pump, but cannot improve the injection coefficient k of the jet pump under the rated working condition. CN201949953U discloses a smooth-profile efficient energy-saving nozzle, which can reduce the flow loss of working media in the nozzle, but lacks the example verification of the performance improvement of an injection pump (ejector). CN104847708A discloses an supersonic velocity ejector of multistage Laval spray tube, mainly utilizes air pressure energy, gaseous hierarchical inflation compression fully mixed, raise the efficiency.

Disclosure of Invention

The technical problem of the invention is solved: after decades of development, the performance of the conventional supersonic gas ejector reaches the upper limit, and the invention adopts the idea of multi-nozzle spatial distribution, configures a brand new ejector structure and greatly improves the performance of the supersonic gas ejector.

The technical solution of the invention is as follows:

the technical scheme includes reconstructing the number of the injection nozzles and the spatial relation between the injection nozzles and a mixing chamber, increasing the contact area between injection flow and injected flow by using a multi-nozzle array, and gradually changing the flow direction pressure gradient in the mixing chamber, so that the mixing distance is shortened, the mixing efficiency is improved, and the performance of the injector is improved.

Compared with the prior supersonic gas ejector, the supersonic gas ejector has the advantages that:

(1) under the condition of keeping the flow rate of the injection working medium and the injection coefficient unchanged, a higher compression ratio of the single-stage injector can be realized, so that the load pressure at the inlet of the injector is greatly reduced, and the suction capacity of the injector is improved;

(2) under the condition of keeping the compression ratio of the ejector unchanged, a larger ejection coefficient can be realized, so that more loads are sucked; if the load flow keeps unchanged, the injection working medium flow can be reduced, the consumption of high-quality working medium is saved, and the operation economy of the injector is improved.

Drawings

FIG. 1 is a schematic view of a supersonic gas ejector with spirally arranged nozzles

FIG. 2 mixing chamber deployment and nozzle array distribution schematic

FIG. 3 Ejection apparatus Performance test Curve

Detailed Description

The principles and features of the present invention are described in detail below with reference to the accompanying drawings.

The invention relates to a supersonic gas ejector with spirally arranged nozzles, which is characterized by comprising a mixing chamber 1, an ejection gas collection chamber 2, a supersonic ejection nozzle array 3, an air inlet chamber 4 and a diffuser 5 (shown in figure 1).

The mixing chamber 1 is a device for mixing supersonic gas discharged by a supersonic jet nozzle array 3 with low-pressure load entering an air inlet chamber 4, the structure of the mixing chamber 1 is a structure of a conical cylinder and a cylinder, the small diameter end of the conical cylinder is connected with the air inlet chamber 4, the cylinder end is connected with a diffuser 5, the full cone angle of the mixing chamber 1 is 7-10 degrees, a mounting hole array for mounting the supersonic jet nozzle array 3 is processed on the side surface of the conical cylinder of the mixing chamber 1, the mounting hole array is distributed according to a multi-head spiral line, the number of heads of the multi-head spiral line is 5-20, the pitch of each spiral line is about 30-70mm, the lift angle β of each spiral line is 1-5 degrees, the axial distance of adjacent mounting holes on each spiral line is about 20-40mm, the distance in the spiral line direction is 60-120mm, the length of each spiral line can be determined according to the number of heads of the multi-head spiral line, the number of the mounting holes on each spiral line can be determined according to the axial distance of the mounting holes (figure 2), and the included angle α.

The injection gas collection chamber 2 is a device which is connected with an external high-pressure injection gas pipeline by an injector, buffers and rectifies, and is connected with the external high-pressure injection gas pipeline by a flange or welding mode. The gas collection chamber is of an annular cavity structure, and the area axial distribution of the inner profile meets the design principle of equal pressure.

The supersonic velocity injection nozzle array 3 is used for accelerating injection gas to supersonic velocity. The single supersonic velocity injection nozzle is a typical Laval nozzle, the inner profile surface is a curved surface, and the external dimension is consistent with the dimension of the mounting hole of the mixing chamber 1. The Mach number range of the outlet of the single supersonic velocity injection nozzle is 1.5-4.0, and the area of the outlet is 1-5% of the area of the outlet of the mixing chamber 1. The number of nozzles included in the supersonic nozzle array is typically 50-300, determined by the ratio of the mixing chamber 1 exit area to the individual supersonic ejector nozzle exit area.

The air inlet chamber 4 is a connecting interface and a flow passage of the ejector and an external low-pressure injected gas pipeline or container, is connected with the external low-pressure injected gas pipeline or container by adopting a flange or welding mode, and the diameters of the interface and the flow passage are determined according to the technical requirements.

Diffuser 5 is used for reducing the speed and pressurizing and discharging the gas mixture in mixing chamber 1 to downstream equipment or atmosphere, and longitudinal section is the toper structure of expansion, and the expansion half angle is 4 ~ 10. The size of the inlet of the diffuser 5 is consistent with that of the outlet of the mixing chamber 1, the size of the outlet is consistent with that of the inlet of downstream equipment, and if the air is exhausted, the size of the outlet is calculated according to the outlet pressure as the atmospheric pressure.

The working process of the supersonic gas ejector adopting the spirally arranged nozzles is as follows.

Starting the ejector: and (3) closing the air inlet chamber 4, opening the injection air collection chamber 2 until the pressure in the injection air collection chamber and the inlet pressure of the mixing chamber 1 reach a set value (determined by design) and keep stable, and successfully starting the ejector.

The ejector normally works: the air inlet chamber 4 is opened to keep the supply of the injection gas/injected gas, and the injector enters a normal working state.

Shutdown of the ejector: firstly, closing the air inlet chamber 4 until the inlet pressure of the mixing chamber 1 is restored to a set value; and secondly, closing the ejector gas collection chamber 2 and stopping the ejector.

The ejector has the working effects that: to verify the performance of supersonic gas injectors using helically arranged nozzles, applicants compared the performance of the injector to conventional single stage injectors (fig. 3). The test result shows that: when the injection coefficient k is zero, the compression ratio epsilon of the supersonic gas injector adopting the spirally arranged nozzles is 300-400 (curve 1), and the compression ratio epsilon of the conventional single-stage injector is 12, namely the compression ratio epsilon is improved by 24-32 times; when the injection coefficient k is 0.01, the compression ratio epsilon of the supersonic gas injector adopting the spirally arranged nozzles is 70, while the compression ratio epsilon of the conventional single-stage injector is 7, namely the compression ratio epsilon is improved by 9 times. The test verification result shows that the compression ratio epsilon of the supersonic gas ejector of the spirally arranged nozzles under the condition of the same ejection coefficient k is higher than that of the conventional single-stage ejector, and the performance and the economical efficiency of the ejector are improved to a certain extent compared with those of the conventional single-stage ejector.