阅读说明：本技术 射流泵 (Jet pump ) 是由 丹尼尔·金提亚 卢卡斯·加布里斯 克里斯蒂安·卡尔 格里特·冯·布莱腾巴赫 米哈尔·萨达克 于 2020-03-30 设计创作，主要内容包括：本发明涉及一种射流泵(10),包括用于加速一推进剂的一射流喷嘴(14),其中所述射流喷嘴(14)具有一收敛入口部分(28)及连接到所述收敛入口部分(28)的一出口部分(26),其中所述出口部分(26)包括一内壁(38)并且以一开口角度(16)发散,其中根据本发明,所述开口角度(16)设计成使以亚音速流过所述出口部分(26)的一推进剂从所述内壁(38)中释放,并且使以超音速流过所述出口部分(26)的一推进剂通过所述内壁(38)来引导。因此,本发明提供一个自动化、具有成本效益及简单改变至不同压力比率的所述射流泵(10)。(The invention relates to a jet pump (10) comprising a jet nozzle (14) for accelerating a propellant, wherein the jet nozzle (14) has a converging inlet section (28) and an outlet section (26) connected to the converging inlet section (28), wherein the outlet section (26) comprises an inner wall (38) and diverges at an opening angle (16), wherein according to the invention the opening angle (16) is designed such that a propellant flowing at subsonic speed through the outlet section (26) is released from the inner wall (38) and a propellant flowing at supersonic speed through the outlet section (26) is guided through the inner wall (38). The present invention thus provides an automated, cost-effective and simple to change to different pressure ratios of the jet pump (10).)

1. Jet pump comprising a jet nozzle (14) for accelerating a propellant, wherein the jet nozzle (14) has a converging inlet portion (28) and an outlet portion (26) connected to the converging inlet portion (28), wherein the outlet portion (26) comprises an inner space (40), the inner space (40) being surrounded by an inner wall (38) and diverging at an opening angle (16), characterized in that the opening angle (16) is configured such that a propellant flowing at subsonic speed through the outlet portion (26) is released from the inner wall (38) and such that a propellant flowing at supersonic speed through the outlet portion (26) is guided through the inner wall (38).

2. The jet pump according to claim 1, characterized in that the inner wall (38) of the outlet portion (26) is configured such that the propellant flowing through the outlet portion (26) is released from the inner wall (38) during a transition from supersonic to subsonic.

3. The jet pump according to claim 1 or 2, characterized in that the inner wall (38) of the outlet portion (26) is configured such that the propellant flowing through the outlet portion (26) is positioned against the inner wall (38) during a transition from supersonic to subsonic and is guided by the inner wall (38).

4. The jet pump as claimed in any of claims 1 to 3, characterized in that a pressure relationship between a propellant pressure of the propellant and a suction pressure after the outlet portion (26) is between 1.05 and 5, preferably between 1.1 and 2.5.

5. The jet pump as claimed in any of claims 1 to 4, characterized in that the opening angle (16) is greater than 7 °.

Technical Field

The invention relates to a jet pump comprising a jet nozzle for accelerating a propellant, wherein the jet nozzle has a converging inlet portion and an outlet portion connected to the converging inlet portion, wherein the outlet portion of the preamble of claim 1 has an inner space which is surrounded by an inner wall and which diverges at an opening angle.

Background

Jet pumps use a fluid jet containing a propellant to suck and accelerate an inhalation medium. The pumping action is caused by the propellant flowing through the inhalation medium, which is also carried by the propellant when the flow rate of the propellant is sufficiently high. To accelerate a propellant, the propellant is directed under pressure through a nozzle, thereby accelerating the propellant. A converging nozzle is used to accelerate the propellant in the jet pump if the suction pressure and the propellant pressure have a subcritical pressure relationship. In the case of supercritical pressure relationships, a converging/diverging nozzle, the so-called Laval nozzle (Laval nozzle), is used to further accelerate the propellant that has been accelerated to sonic velocity in the converging portion of the Laval nozzle. Since the diverging portion of the laval nozzle acts as a diffuser for the propellant, the laval nozzle carrying the propellant flowing at subsonic speeds will result in a reduced flow rate.

Disclosure of Invention

It is an object of the present invention to provide an improved jet pump capable of operating at subcritical and supercritical pressure relationships.

The main features of the invention are set forth in the characterizing part of claim 1. Claims 2 to 8 relate to several embodiments.

The invention relates to a jet pump comprising a jet nozzle for accelerating a propellant, wherein the jet nozzle has a convergent inlet section and an outlet section which is connected to the convergent inlet section, wherein the outlet section comprises an interior space which is surrounded by an inner wall and diverges at an opening angle, wherein according to the invention the opening angle is configured such that a propellant flowing at subsonic velocity through the outlet section is released from the inner wall and that a propellant flowing at supersonic velocity through the outlet section is guided through the inner wall.

The present invention provides a jet pump having a jet nozzle whose converging inlet section accelerates a propellant flowing through the converging inlet section, wherein the propellant flows at subsonic velocity before flowing through the inlet section. If subsonic velocity continues after the flow through the inlet portion and the accelerated propellant, the propellant also flows subsonically through the outlet portion. In this case, the outlet portion of the jet nozzle has a diverging inner wall, that is to say the cross section of the outlet portion increases from the converging inlet portion. In this case, the jet nozzle may be a specially configured Laval nozzle (specially structured Laval nozzle). In this case, the opening angle of the diverging inner walls is so large that the propellant flowing through the outlet portion at subsonic speed is released from the inner walls of the outlet portion. Thus, the outlet portion of the jet nozzle does not act as a diffuser for the propellant flowing at subsonic speeds, thereby not causing a slowing of the propellant velocity as it flows through the outlet portion. Instead, only the convergent inlet portion of the jet nozzle acts on the propellant flowing at subsonic speed. The converging inlet portion of the jet nozzle acts as a converging nozzle for the propellant flowing at subsonic speeds. If the propellant is accelerated to sonic speed by the converging inlet portion, the propellant will be further accelerated by the diverging interior space of the outlet portion. In this case, the propellant is guided by the diverging inner wall of the outlet portion, since in this case the propellant is not released from the inner wall. In this case, the outlet portion acts as a nozzle for the propellant flowing at supersonic velocity and further accelerates the propellant. Thus, the jet nozzle acts as a laval nozzle for propellant flowing at supersonic velocity.

Accordingly, the present invention provides a jet pump operable with a single jet nozzle under both subcritical pressure conditions, i.e. when the propellant is at subsonic velocity to generate the pumping action, and supercritical pressure conditions, i.e. when the propellant is at supersonic velocity to generate the pumping action. In this case, the action of the outlet portion on the flowing propellant is automatically adjusted by the opening angle of the inner wall. Thus, as a result of the present invention, an automated, cost-effective and simple switching to different pressure relationships of the jet pump is provided.

The inner wall of the outlet portion may be configured such that the propellant flowing through the outlet portion is released from the inner wall during a transition from supersonic to subsonic. In other words, the inner wall of the outlet portion may be configured such that the propellant flowing through the outlet portion is released from the inner wall during a transition from a supercritical pressure relationship to a subcritical pressure relationship.

Therefore, the pressure during the operation of the jet pump can be changed from the supercritical pressure relationship to the subcritical pressure relationship, with pressure shock being prevented during the switching operation. This brings about an additional expansion of the range of application of the jet pump.

Furthermore, the inner wall of the outlet portion may be configured such that the propellant flowing through the outlet portion during a transition from subsonic to supersonic is positioned (position) against and guided by the inner wall. In other words, the inner wall of the outlet portion may be configured such that the propellant flowing through the outlet portion is positioned (position) against and guided by the inner wall during a transition from a subcritical pressure relationship to a supercritical pressure relationship.

Thus, a frictionless transition from a subcritical pressure relationship to a supercritical pressure relationship may be performed. This further expands the range of application of the jet pump.

Furthermore, a pressure relation of a propellant pressure of the propellant to a suction pressure at the outlet portion may be between 1.05 and 5, preferably between 1.1 and 2.5.

Thus, the jet pump can operate over a wide range of pressures, where a pressure relationship compared to a desired suction pressure can be subcritical or supercritical.

Thus, a sufficient suction pressure is provided for operation of the jet pump at a low pressure relationship where the propellant flows at subsonic speeds and at a high pressure relationship where the propellant flows at supersonic speeds.

Thus, the jet pump has subcritical and supercritical operating ranges operable therein. Thus, the jet pump can be operated in a wide range of applications.

Advantageously, the opening angle is greater than 7 °.

The opening angle is greater than 7 °, further facilitating the release of the propellant flowing through the outlet portion at subsonic velocity from the inner wall. Thus, the propellant flowing through the outlet portion at subsonic speed is prevented from adhering to the inner wall of the outlet portion.

Drawings

Other features, details and advantages of the invention will be understood from the wording of the claims and from the following description of several embodiments with reference to the accompanying drawings, in which:

figure 1 is a schematic view of a jet pump,

FIGS. 2a, b are several schematic views of a fluidic nozzle, an

Fig. 3a, b are schematic views of examples of outlet portions.

Detailed Description

Fig. 1 is a schematic cross-sectional view of a jet pump, which is designated generally by the reference numeral 10.

The jet pump 10 has a propellant tank 12, a nozzle 14, an inhalation medium tank 18, a mixing chamber 20 and a diffuser 22.

The propellant is arranged in the propellant canister 12. In this case, the propellant may be a compressible propellant. The propellant can be stored in the propellant can 12 under pressure or under pressure in the propellant can 12. The pressure relationship may for example be between 1.05 and 5, preferably between 1.1 and 2.5. At this propellant pressure, the propellant flows from the propellant can 12 to the nozzle 14 during operation of the jet pump 10. This may be indicated by arrow 30.

In this case, the propellant nozzle 14 has a convergent inlet portion 28 and an outlet portion 26, the outlet portion 26 having a divergent interior space 40. The outlet portion 26 and the converging inlet portion 28 are connected to each other. The connection location of the converging inlet portion 28 to the outlet portion 26 has the smallest cross-section of the nozzle 14.

The converging inlet portion 28 has a tapered cross-section (cross section high tapes). The propellant initially flows into a region of the converging inlet portion 28 having a large cross-section. Due to the tapering of the cross-section of the convergent inlet portion 28, the propellant flowing through the convergent inlet portion 28 is accelerated.

Depending on the propellant pressure, the propellant is accelerated to subsonic or sonic speeds by the converging inlet portion 28 as it flows through the converging inlet portion 28.

The outlet portion 26 adjoins the tapered end of the converging inlet portion 28. In this case, the outlet portion 26 includes an inner wall 38, the inner wall 38 laterally surrounding the interior space 40. In this case, in one embodiment, the inner wall 38 may surround the inner space 40 in the form of a conical covering surface (as shown in fig. 3 a). In another embodiment, the inner wall 38 may have a bell-shaped covering surface (as shown in fig. 3 b) to surround the inner space 40.

In this case, the inner space 40 has an inlet opening which is connected to the outlet opening of the converging inlet portion 28. Furthermore, the inner space 40 has an outlet opening which is larger than the inlet opening of the inner space 40. The inner wall 38 extends between the inlet opening and the outlet opening of the inner space 40. In this case, the interior 40 is embodied in a divergent manner and diverges at an opening angle 16. The inner wall 38 directly defines the opening angle 16 according to the narrowest cross-section at the inlet opening of the inner space 40. In this case, the opening angle 16 of the inner wall 38 may change with increasing distance from the inlet opening.

In this case, the opening angle 16 is selected such that a propellant flowing subsonic through the outlet portion 26 is released from the inner wall 38 and a propellant flowing supersonic through the outlet portion 26 is directed 38 through the inner wall. That is, the inner wall 38 does not interfere with a propellant flowing through the outlet portion 26 at subsonic speeds. Conversely, the propellant flowing at subsonic speed is released from the inner wall 38 and acts as a jet from the outlet opening of the converging inlet portion 28, through the outlet portion 26 and out of the nozzle 14.

The opening angle 16 is further selected such that a propellant flowing at supersonic velocity through the outlet portion 26 is directed by the inner wall 38. In this case, the expansion of the propellant flowing through the outlet portion 26 (perpendicular to the flow direction) is limited by the inner wall 38. Thus, an outer region of the flow of the propellant flows along the inner wall 38.

In this case, the opening angle 16 may be at least 7 °. An upper limit of the opening angle 16 may be, for example, between 8 ° and 45 °.

The propellant is further accelerated and exits the outlet portion 26 at an increased supersonic velocity due to expansion perpendicular to the flow direction and limited by the inner wall 38.

After exiting the outlet portion 26, the propellant flows through an opening of the inhalation media canister 18 and creates a suction pressure.

The inhalation media is also carried and accelerated by the propellant flowing through the inhalation media canister 18. The propellant and the inhalation medium thus reach the mixing chamber 20. The propellant and the inhalation medium are mixed together while they flow through the mixing chamber 20.

The mixing chamber 20 adjoins the diffuser 22, in which the propellant and the inhalation medium mixed therewith are decelerated. The diffuser 22 includes an outlet opening 24. The propellant and the suction medium can flow out of the jet pump through the outlet opening 24.

Fig. 2a and 2b are schematic cross-sections through the jet nozzle 14, wherein the flow of the propellant through the jet nozzle 14 is represented by several flow lines 32, 34.

In this case, the propellant in fig. 2a is accelerated to sonic velocity by the converging inlet portion 28. In the converging inlet portion 28, this is represented by the plurality of merged flow lines 32. The propellant, which has been accelerated to sonic velocity, flows from the converging inlet portion 28 into the outlet portion 26. In the outlet portion 26, the streamlines 32 diverge with respect to one another. In this case, the plurality of outer flow lines 32 extend along the inner wall 38, whereby it is represented that the propellant is guided along the inner wall 38 through the inner space 40. In this case, the propellant is expanded and the velocity is thus further supersonic.

In fig. 2b, the propellant is also accelerated by the convergent inlet section 28, but the velocity of the propellant remains below sonic velocity. The propellant thus exits the converging inlet portion 28 at subsonic speed. The plurality of flow lines 34 are compressed in the converging inlet portion 28.

Since the opening angle 16 of the diverging inner wall 38 is selected such that a propellant flowing at subsonic speed is released from the diverging inner wall 38, the propellant does not expand in the outlet portion 26 but rather acts as a free jet flowing through the outlet portion 26. This is depicted by the plurality of flow lines 34 in the outlet portion 26, which flow lines 34 extend substantially parallel to each other. The free jet has an almost constant width 36 in the outlet portion 26.

Thus, the width 36 of the subsonic flow of the propellant in the outlet portion 26 is smaller than a net width of the interior space 40 laterally delimited by the inner wall 38, wherein the net width is increased by the diverging inner wall 38.

Thus, the inner wall 38 avoids acting as a diffuser for the propellant flowing at subsonic speeds, and the propellant is braked by the outlet portion 26.

The pressure of the propellant in the converging inlet portion 28 may increase or decrease during operation. In this case, the inner wall 38 of the outlet portion 26 is configured such that the propellant flowing through the outlet portion 26 is released from the inner wall 38 during a transition from a supercritical pressure relationship to a subcritical pressure relationship. Conversely, the propellant flowing through the outlet portion 26 is positioned against the inner wall 38 during a transition from a subcritical pressure relationship to a supercritical pressure relationship and is directed through the inner wall 38.

This means that the velocity of the propellant in the outlet portion 26 can be varied between supersonic and subsonic speeds without interrupting the operation of the jet pump 10. Thus, the jet pump 10 can operate at both supercritical and subcritical pressure relationships.

In this case, a subcritical pressure relationship of subsonic flow of the propellant through the outlet portion 26 may be adjusted at an intake pressure of 0.98 Pa and a propellant pressure of 1.1 Pa, wherein the flowing propellant is released from the inner wall 38.

A supercritical pressure relationship of the propellant flowing through the outlet portion 26 at supersonic velocity may thus be adjusted at an inhalation pressure of 0.98 pa and a propellant pressure of 2.5 pa, wherein the flowing propellant is guided by the inner wall 38.

The invention is not limited to one of the several embodiments described above but can be modified in various ways.

All the several features and several advantages, including several structural details, several spatial arrangements and several method steps, which can be derived from the claims, the description and the attached drawings, can be of inventive significance both individually and in very different combinations.

List of symbols of elements

10 jet pump

12 propellant can

14 nozzle

16 opening angle

18 suction medium tank

20 mixing chamber

22 diffuser

24 outlet opening

26 outlet section

28 convergent inlet section

30 direction of flow

32 supersonic streamlines

34 several subsonic flow lines

36 width of free jet

38 inner wall

40 inner space