阅读说明：本技术 引射充气系统用引气环 (Air-entraining ring for injection inflation system ) 是由 邱义芬 张晓� 梅志光 于 2018-06-15 设计创作，主要内容包括：本发明提供一种引射充气系统用引气环,其特征在于,所述引气环上设置有多个引射喷嘴,所述多个引射喷嘴均分在引气环一直径线的两侧,所述引气环上位于所述直径线同一侧的多个引射喷嘴均布设置在180°-2α的圆心角度范围内,α表示靠近直径线端部的引射喷嘴相对于直径线的角度。该设备能够在危机发生时进行快速引射充气,使得充气容积达到救生用压力范围后尽快帮助旅客逃生。(The invention provides a bleed ring for an injection inflation system, which is characterized in that a plurality of injection nozzles are arranged on the bleed ring and are uniformly distributed on two sides of a diameter line of the bleed ring, the plurality of injection nozzles on the bleed ring, which are positioned on the same side of the diameter line, are uniformly distributed in a circle center angle range of 180-2 alpha, and alpha represents the angle of the injection nozzle close to the end of the diameter line relative to the diameter line. The device can rapidly inject and inflate when a crisis occurs, so that the passenger can be helped to escape as soon as possible after the inflation volume reaches the pressure range for lifesaving.)

1. A bleed air ring for an injection inflation system, which is characterized in that,

a plurality of injection nozzles are arranged on the gas guide ring,

the plurality of injection nozzles are uniformly distributed on two sides of a diameter line of the air guide ring,

a plurality of injection nozzles which are positioned on the same side of the diameter line on the air guide ring are uniformly distributed within the range of the angle of the circle center of 180-2 alpha,

alpha represents the angle of the injection nozzle close to the end of the diameter line relative to the diameter line, and is less than alpha by 0 degrees.

2. A bleed air ring for an injection inflation system, which is characterized in that,

the gas-guiding ring is provided with a plurality of openings for installing the injection nozzles,

the plurality of openings are evenly distributed on two sides of a diameter line of the air guide ring,

a plurality of openings on the air entraining ring, which are positioned on the same side of the diameter line, are uniformly distributed and arranged in the range of the angle of the circle center of 180-2 alpha,

alpha denotes the angle of the opening near the end of the diametrical line relative to the diametrical line, 0 < alpha.

3. The bleed air ring according to claim 1 or 2,

α＜30°。

4. the bleed air ring according to claim 1 or 2,

α＝26°～27.5°。

5. the bleed air ring according to claim 1 or 2,

α＝10°～15°。

6. the bleed air ring according to claim 1 or 2,

a high pressure bleed air duct is provided along the diametrical line in communication with the bleed air ring,

the axis of the high pressure bleed air duct coincides with the diametrical line,

and the gas from the high-pressure bleed air pipe is ejected through the injection nozzle.

7. The bleed air ring according to claim 1 or 2,

the air-entraining pipe is fixed on the high-pressure air-entraining pipe.

8. The bleed air ring according to claim 1 or 2,

the injection nozzle is a Laval nozzle,

the inlet diameter D1 of the Laval nozzle is 2.5 mm-3.5 mm;

the outlet diameter D2 of the Laval nozzle is 2.5 mm-3.5 mm.

9. The gas directing ring of claim 7,

D1＝D2。

10. the bleed air ring according to claim 1 or 2,

the injection nozzle is a Laval nozzle,

the throat diameter D3 of the Laval nozzle is 1.7 mm-2.0 mm.

Technical Field

The invention belongs to the field of aviation, navigation and fire emergency escape, and particularly relates to an ejector of a passenger escape rapid ejection inflation system.

Background

The passenger flees for one's life to draw and penetrate the inflatable system fast and by the high pressureThe device comprises a gas source (such as a gas cylinder filled with high-pressure gas), a high-pressure reducing and stabilizing valve, a high-pressure ejector, a high-pressure bleed gas pipeline and the like, and is shown in figure 1. The eductor structure is shown in fig. 2, wherein the nozzle may preferably take the form of both an expanding nozzle and a laval nozzle. High pressure N is arranged in the high pressure air source 10₂With CO₂The mixed working medium, the high-pressure reducing and stabilizing valve 20 reduces the pressure of the mixed working medium to the pressure required by injection, the mixed working medium flows into the injector 40, and a large amount of ambient air is sucked to enter an inflation volume (not shown) together for rapid injection and inflation, so that the inflation time is shortened, and the escape of passengers is facilitated as soon as possible. The flow rate of the mixed working medium is injection flow rate, the flow rate of the sucked ambient atmosphere is suction flow rate, and the ratio of the suction flow rate to the injection flow rate is injection ratio.

The passenger escape rapid injection inflation system needs to enable the inflation volume to reach the required pressure in the shortest possible time, so that the system is required to have large injection flow and high injection ratio, and meanwhile, the volume and the weight of the system cannot be too large. Parameters such as mixed working medium components, filling quality, injection pressure, a high-pressure injector structure and the like in the high-pressure gas source have great influence on the performance required by the system, and the parameters need to be reasonably designed and determined so as to facilitate the wide application of the rapid injection inflation system.

Disclosure of Invention

In order to solve the problems in the prior art, a first aspect of the invention provides a bleed ring for a pilot inflation system, which is characterized in that a plurality of pilot nozzles are arranged on the bleed ring, the plurality of pilot nozzles are uniformly distributed on two sides of a diameter line of the bleed ring, the plurality of pilot nozzles on the same side of the diameter line on the bleed ring are uniformly distributed within a circle center angle range of 180-2 α, α represents an angle of the pilot nozzle close to the end of the diameter line relative to the diameter line, and α is smaller than 0 °.

The invention provides a bleed ring for an injection inflation system, which is characterized in that a plurality of openings for installing injection nozzles are arranged on the bleed ring, the openings are uniformly distributed on two sides of a diameter line of the bleed ring, the openings on the same side of the diameter line on the bleed ring are uniformly distributed within the range of a circle center angle of 180-2 alpha, alpha represents the angle of the opening close to the end part of the diameter line relative to the diameter line, and alpha is more than 0 degree.

In the bleed air ring as described above, it is preferable that: alpha is more than 0 degree and less than 30 degrees.

In the bleed air ring as described above, it is preferable that: alpha is 26-27.5 degrees.

In the bleed air ring as described above, it is preferable that: alpha is 10-15 deg

In the bleed air ring as described above, it is preferable that: the diameter line is provided with one with the high pressure bleed pipe of air ring intercommunication, the axis of high pressure bleed pipe with the coincidence of diameter line, the gas that comes from high pressure bleed pipe is through drawing the injection nozzle blowout.

In the bleed air ring as described above, it is preferable that: the air-entraining pipe is fixed on the high-pressure air-entraining pipe.

In the bleed air ring as described above, it is preferable that: the injection nozzle is a Laval nozzle, and the inlet diameter D1 of the Laval nozzle is 2.5-3.5 mm; the outlet diameter D2 of the Laval nozzle is 2.5 mm-3.5 mm.

In the bleed air ring as described above, it is preferable that: d1 ═ D2.

In the bleed air ring as described above, it is preferable that: the injection nozzle is a Laval nozzle, and the throat diameter D3 of the Laval nozzle is 1.7 mm-2.0 mm.

Through experimental verification, if the air entraining ring with the structure is used for the ejection and inflation system for emergency escape, the purpose of quick inflation can be realized, even the ejection ratio in the ejection process can reach more than 2.5, and the air bag for emergency escape can be quickly filled with air.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the invention and are not intended to limit the invention.

Fig. 1 is a schematic structural diagram of a passenger escape rapid injection inflation system.

Fig. 2 is a structural view of a high-pressure ejector.

FIG. 3 shows N in a mixed working fluid₂Graph of the effect of content on aeration performance.

FIG. 4 is a layout view of an 18-nozzle eductor nozzle with an air ring.

FIG. 5 is a schematic view of a Laval nozzle configuration.

The reference numerals in the figures are explained below:

10, a high-pressure gas source; 20 high-pressure reducing and stabilizing valve; 30 high pressure bleed air conduit; 35 high-pressure bleed air pipes; 40, an ejector; 50 injecting an inflow port; 60 a mixing chamber; 70 a suction chamber; 80 injection nozzle; 350 closed end of high pressure bleed air pipe; 553 an inner lead ring; 557 outer gas ring; the diameter of the Dh mixing chamber; lh mixing chamber total length.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. For the electrical and communication fields, either a wired connection or a wireless connection is possible. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention provides an ejector of a passenger escape rapid ejection inflation system.

1. High-pressure gas source N₂With CO₂Determination of the composition of a mixed working fluid

The high-pressure gas source has limited volume and is stored in the high-pressure gas cylinder in a high-pressure form, and the quick injection inflation system can only utilize limited mixed working media to suck ambient air as much as possible in a short time, so that the quality of gas flowing into the inflation volume in the injection stage is improved. Therefore, the parameter design should improve the jet flow and the jet ratio as much as possible.

The inventor finds that the working medium of the high-pressure gas source is made of pure N₂Gradually increasing CO₂In the process of content, i.e. with mixing working medium N₂The mass fraction is reduced, the injection flow of the system is gradually increased, the change of the injection flow is not obvious, and the injection ratio is gradually reduced. In this respect, N is present in the mixed working fluid₂The high content is beneficial to quick aeration because the injection ratio is high under the condition, which shows that the injection efficiency is high, and more ambient air can be sucked by the limited mixed working medium quality. However, when N is present in the pressurized gas source₂When the content is very high, the mass of the working medium stored in the air source under the same volume and pressure is very small, in the injection process, along with the consumption of the working medium of the air source, the pressure of the residual working medium in the air source is very quickly reduced, the injection inflation time is greatly shortened, and the injection inflation process is too short, so that the ambient air quantity sucked into the inflation volume in the injection process is reduced, the inflation pressure cannot be reached, and the safe escape opportunity of passengers is reduced. Therefore, the CO in the mixed working medium is properly increased₂The content of the air can effectively increase the quality of working medium in a high-pressure air source, maintain the pressure of the air source in the injection process, prolong the injection process, so as to suck enough ambient air and meet the pressure required by the inflation volumeForce, the passenger can escape safely. Of course, the CO in the working medium is mixed along with the high-pressure gas source₂The content is increased, the quality of the gas source filling working medium is increased quickly, and the weight of the quick injection and inflation system is increased and is not beneficial to the system.

N in high-pressure gas source working medium₂The relationship between the mass fraction of (c), the injection ratio and the mass of the mixture (the charged volume) is shown in fig. 3.

According to the graph 3, the components of the mixed working medium need to be reasonably determined, the requirement of the inflation volume of the system is firstly ensured, the injection ratio of the injector is improved as much as possible under the condition, and meanwhile, the total mass of the gas source mixed working medium is reduced. As can be seen from FIG. 3, when N is contained in the gas mixture₂When the mass fraction is less than about 0.4, the mass of the mixed gas increases very rapidly, and N is₂The content is continuously reduced, the injection efficiency is obviously lower, and the method is not favorable for fully utilizing the working medium in the gas source.

Therefore, the invention selects CO₂And N₂The mixed gas is used as a mixed working medium for a charging high-pressure gas source, and CO is mixed according to the research of the inventor₂And N₂N in mixed working media₂Is determined to be in the range of 0.4 to 0.7 (i.e., N)₂The mass fraction of (b) is 40% to 70%), for example, 0.45, 0.48, 0.50, 0.53, 0.55, 0.57, 0.60, 0.62, 0.65, 0.68, etc.

In addition, CO in the high-pressure gas cylinder₂And N₂The mixed gas (2) is present in a pressure range of 2MPa to 5MPa, and may be, for example, 2.2MPa, 2.4MPa, 2.6MPa, 3MPa, 3.3MPa, 3.6MPa, 3.9MPa, 4.0MPa, 4.1MPa, 4.4MPa, 4.6MPa, 4.8MPa or the like.

The high-pressure gas cylinder for storing the mixed working medium can be made of any material which can bear the pressure and can not react with any gas in the mixed working medium.

2. Injection pressure

For a rapid injection and inflation system, the injection pressure is very high, the ratio of the injection pressure to the system back pressure is far greater than 10, and the outlet of the nozzle is supersonic airflow. Under the condition, the injection pressure is improved, the injection flow can be increased proportionally, the injection ratio is reduced, and the injection efficiency is low, so that the gas source working medium is not utilized fully. On the other hand, if the injection pressure is too low, too low mixing flow rate is caused by low injection flow rate, and the requirement of inflation cannot be met. Therefore, the injection pressure setting is very important, and the reasonable setting of the pressure can also enable the system to meet the requirements of quick and efficient inflation. In order to ensure the injection efficiency of the system, the total pressure absolute pressure at an injection flow inlet of the Laval nozzle injector is preferably not more than 3.4 MPa; for an expanding nozzle eductor, it is preferred that the total pressure absolute pressure at the inducer inlet be no greater than 3.8 MPa.

That is, the pressure of the gas from the high-pressure reducing and pressure stabilizing valve in fig. 1 can be selected to be different according to the type of the nozzle.

3. Ejector structure

As shown in fig. 1 and 2, the ejector for an ejector aeration system developed by the inventor of the present invention includes: inhale room 70, mixing chamber 60, and set up in inhale the portion of drawing in the room 70, should draw the portion of drawing to include: a high pressure bleed air pipe 35 connected to a high pressure air source; a bleed air member (bleed ring) communicating with the high-pressure bleed air pipe 35 and disposed in the suction chamber, and a plurality of pilot nozzles 80 installed on the bleed air member;

after the pressure of the gas from the high-pressure gas source 10 is reduced to a specified pressure through the high-pressure reducing and stabilizing valve 20, the gas enters an injection flow inlet of the high-pressure gas guide pipe 35 through one or more high-pressure gas guide pipelines 30 and is further injected into the mixing chamber 60 through the gas guide part and the injection nozzle 80, when the high-pressure gas enters the injector, a large amount of ambient atmosphere is sucked from an atmosphere opening end of the suction chamber 70 to form a suction flow, and then the high-pressure gas enters the mixing chamber 60 to be mixed with the high-pressure gas from the injection part to form a mixed flow, and then the mixed flow jointly enters an inflation volume (such as a life-saving airbag) to be rapidly injected and inflated, so that the inflation volume reaches a pressure range for life saving and helps passengers to.

The high-pressure bleed air pipe 35 may be fixed to the suction chamber 70, the bleed air member may be fixed to the high-pressure bleed air pipe 35, or they may be directly placed in the suction chamber 70 as needed.

As a specific embodiment of the air-entraining component, an annular air-entraining ring is often used to achieve the purpose of the invention, for example, a plurality of openings are formed on an air-entraining ring with a certain size, and the injection nozzle is installed on the air-entraining ring through the openings.

For example, a plurality of injection nozzles arranged on the air guide ring are uniformly distributed on two sides of a diameter line of the air guide ring, and the plurality of injection nozzles on the air guide ring and positioned on the same side of the diameter line are required to be uniformly distributed within a range of a central angle of 180-2 alpha, wherein alpha represents an angle of the injection nozzle close to the end of the diameter line relative to the diameter line.

The openings for installing the injection nozzles are uniformly distributed on two sides of a diameter line of the air guide ring, the openings on the air guide ring, which are positioned on the same side of the diameter line, are uniformly distributed within a circle center angle range of 180-2 alpha, and alpha represents an angle of the opening close to the end of the diameter line relative to the diameter line.

The size of the angle alpha can be determined according to the size of the air guide ring and the size of an ejector for placing the air guide ring, for example, the angle alpha is less than 30 degrees or 10-15 degrees, and the requirement of quick air inflation can be better met in the angle range.

As the air introducing ring, only one air introducing ring on which the plurality of injection nozzles 80 are arranged may be provided, or a plurality of air introducing rings respectively provided with the plurality of injection nozzles 80 may be included, such as an inner air introducing ring 553 and an outer air introducing ring 557, where the inner air introducing ring 553 and the outer air introducing ring 557 are both communicated with the high-pressure air introducing pipe 35.

The inner guide ring 553 may communicate with the high pressure guide pipe 35 at one point or at two points, and when two points communicate with each other, it is preferable to communicate with the inner guide ring along the diameter direction of the inner guide ring.

Similarly, the outer bleed ring 557 may be in communication with the high-pressure bleed pipe 35 by one or two locations, and when the two locations are in communication, it is preferably in communication with the outer bleed ring along the diameter direction of the outer bleed ring.

The closed end 350 of the high pressure bleed air duct may be disposed on a wall of the suction chamber, may be disposed on a wall of the bleed ring (or an outer bleed ring wall when there is an inner bleed ring and an outer bleed ring), or may be disposed between the bleed ring wall and the wall of the suction chamber.

As shown in fig. 2, the suction chamber 70 is formed of two sections: a frustum-shaped first section and a cylindrical second section, wherein the large-diameter end (open end facing the atmosphere) of the first section is the ambient atmosphere open end of the suction chamber and is the inflow end of the suction air stream, and the small-diameter end of the first section is the end connected to the second section.

As the distribution mode of the injection nozzles 80 on the bleed ring, the multiple injection nozzles 80 may be uniformly distributed on the whole bleed ring, or equally distributed in a certain angle range on both sides of a certain diameter line of the bleed ring, and in the certain angle range, the high-pressure bleed pipe 35 may be uniformly distributed, or distributed based on other required distributions along the diameter line.

Number and arrangement of nozzles of ejector

The number of the nozzles of the ejector is related to the size of a mixing chamber of the ejector, the size of the mixing chamber changes along with the inflation volume of the rapid ejection inflation system, the ejection flow and the mixing flow are required to be high when the inflation volume is large, and the corresponding size of the mixing chamber of the ejector is large. For the same ejector mixing chamber, the number and the layout of the nozzles have obvious influence on the ejection efficiency. In order to ensure high injection efficiency of the system, the number of the nozzles cannot be too small or too large, and for a certain number of the nozzles, the nozzles should be arranged at proper positions, and the arrangement positions are changed along with the number of the nozzles.

For the mixing chamber diameter range of 80 ~ 100mm, the preferred quantity of drawing nozzle sets up 18, draws the nozzle and for the overall arrangement position analysis in mixing chamber space as follows.

As shown in figure 4, the inside and outside air-guiding rings are arranged in the air-suction chamber of the ejector, wherein 18 injection nozzles are arranged on the air-guiding rings, that is, 18 openings for installing the injection nozzles are arranged on the air-guiding rings, and a high-pressure mixer is arranged on the air-guiding ringsThe substance (can be any high-pressure gas capable of meeting the requirement of inflation for life saving, preferably CO₂And N₂Mixed gas) is guided by the high-pressure bleed pipe 35 to reach the inner bleed ring and the outer bleed ring, and then enters the 18 injection nozzles through the bleed rings to be injected into the mixing chamber, and low-pressure air in the environment is injected and sucked into the suction chamber along the axial direction of the mixing chamber while high-pressure mixed working medium is injected into the mixing chamber, and then enters the mixing chamber.

As an arrangement manner of the 18 injection nozzles, as shown in fig. 4, 12 injection nozzles may be arranged on the outer air guide ring, 6 injection nozzles are arranged on the inner air guide ring, and as a relation between the air guide ring and the injection nozzles, an opening for installing the injection nozzles may be provided on the air guide ring, or the injection nozzles and the air guide ring may be integrated, which may be specifically selected according to actual needs, and the former is generally preferred.

The 12 injection nozzles (or openings for installing the nozzles) arranged on the outer air guide ring are symmetrically arranged at two sides of the pipe axis of the high-pressure air guide pipe, the angle of the nozzle close to the air guide pipe relative to the pipe axis of the high-pressure air guide pipe 35 is represented by beta, and 6 nozzles at each side are uniformly distributed within the angle range of 180-2 beta. The 6 nozzles (or openings for mounting the nozzles) arranged on the inner bleed ring are also arranged symmetrically on both sides of the tube axis of the high-pressure bleed duct 35, the angle of the nozzles close to the bleed duct with respect to the tube axis being denoted by α, and the 3 nozzles on each side being evenly distributed over an angle of 180 ° -2 α. Assuming a mixing chamber diameter D and an inner gas ring centerline diameter D, the inner and outer gas ring centerlines are separated by δ. The nozzle arrangement positions in fig. 4 preferably satisfy the following relationship:

alpha is less than 30 degrees, such as 10 degrees, 12 degrees, 15 degrees, 18 degrees, 20 degrees, 22 degrees, 25 degrees, 26.5 degrees, 27 degrees, 28 degrees, 28.5 degrees, 29 degrees, 29.5 degrees and the like, preferably 26 degrees to 27.5 degrees; β is 10 to 15 °, for example, 11 °, 11.5 °, 12 °, 12.5 °, 13 °, 13.5 °, 14 °, 14.5 °, or the like.

According to experimental verification, if the ejector with the structure is adopted, the ejection ratio in the ejection process can reach more than 2.5, and the requirement of quick inflation is met.

4 Laval nozzle size

As the injection nozzle, a laval nozzle or an expansion nozzle may be used. The requirements for the nozzle structure will be described below by way of example for a Laval nozzle. The Laval nozzle is constructed as shown in FIG. 5, with the inlet, throat and outlet diameters D1, D2, D3, respectively, and the outlet diameter D3 should not be less than the throat diameter D2. The diameter change of the inlet and the outlet of the nozzle can obviously influence the injection flow and the injection efficiency. The large injection flow and the high injection efficiency can fully utilize the high-pressure working medium of the air source to improve the inflation volume, shorten the inflation time and realize quick inflation.

The diameter of the nozzle inlet can adjust the injection flow within a certain range, but the influence on the injection efficiency is not obvious, the injection flow is improved along with the increase of the diameter of the inlet, the injection flow is not increased after the injection flow is increased to a certain value, the diameter of the inlet reaches the optimal state, and the injector can obtain higher injection flow under certain injection pressure.

The diameter of the outlet of the nozzle changes the injection efficiency within a certain range, the injection flow is not obviously influenced, the injection efficiency is obviously improved along with the increase of the diameter of the outlet, the injection efficiency is not improved any more after the diameter of the outlet is increased to a certain value, the maximum value is reached, and the diameter of the outlet reaches the optimal state at the moment. Therefore, the diameter of the outlet has the maximum value, and the ejector is in a high-efficiency working state in the state.

The optimal values of the nozzle inlet and outlet diameters are determined by using CFD analysis software (a commercial software) according to the overall structure of the ejector. The method for determining the maximum nozzle inlet diameter comprises the following steps: parameterizing the nozzle inlet diameter D1 in simulation software, modifying the size value, keeping the rest sizes unchanged, performing simulation analysis, and determining the optimal inlet diameter according to the maximum injection flow; similarly, parameterizing the nozzle outlet diameter D3 in simulation software, modifying the size value, keeping the rest sizes unchanged, performing simulation analysis, and determining the optimal outlet diameter according to the maximum injection ratio.

For the 18-nozzle ejector, when the diameter of the mixing chamber is within the range of 80-100 mm, the inlet diameter D1 of the Laval nozzle is within the range of 2.5-3.5 mm, the throat diameter D2 is within the range of 1.7-2.0 mm, and the outlet diameter D3 is within the range of 2.5-3.5 mm. D1, D2, and D3 satisfy the following relationships:

D1＝D3

when the diameter of the mixing chamber is about 100mm, D1 is D3 is approximately equal to 2. D2, and the optimal value of the diameter of the inlet and the outlet of the nozzle is 3.5 mm.

5. Length to diameter ratio of mixing chamber

In addition, the size structure of the mixing chamber has certain influence on the injection efficiency and the air suction flow. One important parameter is the length to diameter ratio of the mixing chamber of the eductor.

As shown in fig. 2, the mixing chamber 2 includes a first section of constant cross-sectional size and a second section of variable cross-sectional size, wherein the first section is connected to the suction chamber at one end, receives the high-pressure working medium gas or N2 from the injection nozzle and the ambient atmospheric gas sucked from the suction chamber 70, and is connected to the small-caliber end of the second section at the other end, and the second section increases in diameter as it goes away from the small-caliber end, and guides the mixed gas flow into the life-saving inflation volume such as an airbag. The total length of the first section and the second section is Lh, and the length-diameter ratio of the mixing chamber of the ejector is the ratio of the total length Lh of the mixing chamber to the diameter Dh of the constant-section of the mixing chamber.

The influence trend of the mixing chamber length-diameter ratio on the injection performance is changed. When the length-diameter ratio is small, the same high-pressure working medium has low air suction flow and low injection efficiency; along with the increase of the length-diameter ratio, the injection efficiency is gradually increased, but when the length-diameter ratio exceeds 3, the injection ratio is not obviously improved, and the injection ratio is reduced by continuously increasing the length-diameter ratio. The length-diameter ratio of the ejector cannot be too small or too large, otherwise, the ejector volume and weight are too large except possibly reducing the ejection efficiency.

In general, the aspect ratio of the mixing chamber in the present invention is 2.2 to 3.0, and may be, for example, 2.35, 2.45, 2.60, 2.75, or 2.90.

6. Area ratio of mixing chamber

In addition, the inventor of the present application has found that the area of the mixing chamber of the ejector also has a certain influence on the ejection efficiency and the flow rate of the suction gas. One important parameter is the area ratio of the mixing chamber of the eductor

The area ratio of the mixing chamber of the ejector is the ratio of the flow area of the equal section of the mixing chamber to the minimum total flow area of the nozzle. The minimum total flow area is: the sectional area of the narrowest position of the nozzle x the number of nozzles.

Under the condition of reasonable nozzle layout, the injection efficiency of the quick injection inflation system can be effectively improved by reasonably designing the area ratio of the mixing chamber. When the area ratio is very small, the same high-pressure working medium has low air suction flow and low injection efficiency; the injection efficiency is gradually increased along with the increase of the area ratio; however, when the area ratio is increased to a certain range, the injection ratio is not changed greatly, and the injection ratio is reduced by continuously increasing the area ratio. Therefore, when the ejector ratio is not greatly changed, the area ratio should be reduced as much as possible to reduce the volume and weight of the ejector.

By comprehensive consideration, the area ratio of the mixing chamber is 130-190, so that the volume and the weight of the ejector can be reduced under the condition of not reducing the ejection efficiency.

It will be appreciated by those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Thus, the embodiments disclosed above are illustrative and not exclusive in all respects. All changes which come within the scope of or equivalence to the invention are intended to be embraced therein.