CN113775565B - Impeller structure of rocket engine turbopump - Google Patents

Abstract

The invention discloses an impeller structure of a rocket engine turbo pump, which comprises a centrifugal impeller, the centrifugal impeller comprises a rear disc, a front disc, and a plurality of blades, the blades comprise long blades (41) and short blades (42), the long blades and the short blades have the same outer diameter, and the plurality of long blades and the plurality of short blades are alternately arranged at intervals along the circumferential direction; the characteristic is that at least 51% of the short blades (42) have different leading edge inner diameters/radii. The invention can reduce the pressure pulsation of the impeller cavity, reduce the impact of uneven liquid flow at the pump inlet on the impeller, make the impact of the liquid flow on the impeller tend to be uniform, and thus reduce vibration.

Description

Impeller structure of a rocket engine turbo pump

Technical Field

The invention relates to the technical field of rocket engine turbo pumps, and in particular to an impeller structure of a rocket engine turbo pump.

Background technique

The turbo pump of a rocket engine is mainly composed of an inducer, a centrifugal impeller, a mechanical seal, a bearing, a shaft support system and a housing, etc. However, the centrifugal impeller of the existing turbo pump has the problems of large pressure pulsation and large impact vibration.

Summary of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art and provide an impeller structure for a rocket engine turbo pump. By designing short blades, at least 51% of the leading edge inner diameters/radii of the short blades are unequal. Preferably, the leading edge inner diameters/radii of the various short blades are unequal, which can reduce the pressure pulsation of the impeller cavity, reduce the impact of uneven liquid flow at the pump inlet on the impeller, and make the impact of the liquid flow on the impeller uniform, thereby reducing vibration. By designing the guide portion, the guide portion includes a first arc-shaped portion and a second arc-shaped portion, which can reduce the vortex at the inlet of the short blades, thereby reducing the pressure pulsation of the pump.

In order to achieve the above object, the technical solution adopted by the present invention is:

An impeller structure of a rocket engine turbo pump, comprising a first housing (1), a second housing (2), a third housing (3), a first centrifugal impeller (4), a first spiral inducer (5), a common shaft (6), a second centrifugal impeller (7), a second spiral inducer (8), a mechanical seal (9), and an inlet flow channel. One end of the first housing is connected to the second housing via a connecting piece, and the other end is connected to the third housing via a connecting piece. The upstream end of the first centrifugal impeller is provided with a first spiral inducer, the first spiral inducer is adjacent to the inlet flow channel, the upstream end of the second centrifugal impeller is provided with a second spiral inducer, and the first centrifugal impeller, the first spiral inducer, the second centrifugal impeller, and the second spiral inducer are respectively mounted on the common shaft. A mechanical seal is installed in the first housing and on the outer periphery of the common shaft, the first centrifugal impeller and the second centrifugal impeller are arranged back to back with respect to the mechanical seal, the first pump having the first centrifugal impeller (4) is used to pump cryogenic methane or cryogenic liquid oxygen, and the second pump having the second centrifugal impeller (7) is used to pump cryogenic methane or cryogenic liquid oxygen; the first centrifugal impeller and/or the second centrifugal impeller comprises a rear disc, a front disc, and blades, a plurality of blades are distributed between the rear disc and the front disc along the circumferential direction, the blades comprise long blades (41) and short blades (42), the long blades and the short blades have the same outer diameter, and the plurality of long blades and the plurality of short blades are alternately arranged along the circumferential direction; the characteristic is that: the leading edge inner diameter/radius size of at least 51% of the short blades (42) are different.

Furthermore, the leading edge inner diameters/radii of the short blades (42) are different.

Furthermore, the inner diameter of the leading edge of the short blade (42) is 1.5-2.5 times the inner diameter of the leading edge of the long blade (41).

Furthermore, the short blade (42) has a concave surface and a convex surface which are arranged opposite to each other, and a guide portion (43) is arranged at the leading edge of the short blade 4 and on one side of the concave surface.

Furthermore, the guide portion (43) comprises a first arc-shaped portion (44) and a second arc-shaped portion (45), the first arc-shaped portion and the second arc-shaped portion have a smooth transition, and the protrusion directions of the first arc-shaped portion and the second arc-shaped portion are opposite.

Furthermore, the dimension of the guide portion (43) along the length direction of the blade is 0.05-0.20 times the chord length of the short blade (42).

Furthermore, in the axial cross-sectional view, the leading edge of the short blade (42) has a third arc-shaped portion (46), and the third arc-shaped portion is a part of a circle.

The impeller structure of a rocket engine turbo pump of the present invention makes the leading edge inner diameter/radius size of at least 51% of the short blades unequal through the design of short blades. Preferably, the leading edge inner diameter/radius size of each short blade is unequal, which can reduce the pressure pulsation of the impeller cavity, reduce the impact of uneven liquid flow on the impeller at the pump inlet, make the impact of the liquid flow on the impeller uniform, thereby reducing vibration. Through the design of the guide part, the guide part includes a first arc-shaped part and a second arc-shaped part, which can reduce the vortex at the inlet of the short blade, thereby reducing the pressure pulsation of the pump.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a rocket engine turbo pump according to the present invention;

FIG2 is a schematic diagram of the impeller structure of the rocket engine turbopump of the present invention;

FIG3 is a schematic diagram of the short blade structure of the rocket engine turbopump of the present invention;

FIG. 4 is a schematic diagram of the short blade structure of the rocket engine turbopump of the present invention.

In the figure: a first shell 1, a second shell 2, a third shell 3, a first centrifugal impeller 4, a first spiral inducer 5, a common shaft 6, a second centrifugal impeller 7, a second spiral inducer 8, a mechanical seal 9, a long blade 41, a short blade 42, a guide portion 43, a first arc portion 44, a second arc portion 45, and a third arc portion 46.

Detailed ways

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Fig. 1-4, an impeller structure of a rocket engine turbopump includes a first housing 1, a second housing 2, a third housing 3, a first centrifugal impeller 4, a first spiral inducer 5, a common shaft 6, a second centrifugal impeller 7, a second spiral inducer 8, a mechanical seal 9, and an inlet flow channel. One end of the first housing 1 is connected to the second housing 2 through a connecting piece, and the other end is connected to the third housing 3 through a connecting piece. The upstream end of the first centrifugal impeller 4 is provided with a first spiral inducer 5, and the first spiral inducer 5 is adjacent to the inlet flow channel. The upstream end of the second centrifugal impeller 7 is provided with a second spiral inducer 8. The first centrifugal impeller 4, the first spiral inducer 5, the second centrifugal impeller 7, and the second spiral inducer 8 are respectively installed on the common shaft 6. A mechanical seal 9 is installed in the first housing 1 and on the outer periphery of the common shaft 6. The first centrifugal impeller 4 and the second centrifugal impeller 7 are arranged back to back with respect to the mechanical seal 9. The first pump with the first centrifugal impeller 4 is used for pumping low-temperature methane (such as -160-170°C) or low-temperature liquid oxygen (such as -180-185°C), and the second pump with the second centrifugal impeller 7 is used for pumping low-temperature methane (such as -160-170°C) or low-temperature liquid oxygen (such as -180-185°C).

The first centrifugal impeller 4 and/or the second centrifugal impeller 7 include a rear disc, a front disc, and blades, a plurality of blades are circumferentially distributed between the rear disc and the front disc, the blades include long blades 41 and short blades 42, the long blades 41 and the short blades 42 have the same outer diameter, a plurality of long blades 41 and a plurality of short blades 42 are alternately arranged at intervals along the circumference, and at least 51% of the short blades 42 have different leading edge inner diameters/radii. Preferably, the leading edge inner diameters/radii of the short blades 42 are different (R1, R2, R3...).

The impeller structure of a rocket engine turbopump of the present invention, through the design of short blades 42, makes the leading edge inner diameter/radius dimensions of at least 51% of the short blades 42 unequal. Preferably, the leading edge inner diameter/radius dimensions of each short blade 42 are unequal, which can reduce the pressure pulsation of the impeller chamber, reduce the impact of uneven liquid flow at the pump inlet on the impeller, make the impact of the liquid flow on the impeller tend to be uniform, thereby reducing vibration.

Further, the inner diameter of the leading edge of the short blade 42 is 1.5-2.5 times, preferably 1.75-2.25 times, the inner diameter of the leading edge of the long blade 41 .

As shown in Figures 3-4, further, the short blade 42 has a relatively arranged concave surface/negative pressure surface and a convex surface/pressure surface, and a guide portion 43 is arranged on the leading edge of the short blade 42 and on the concave side thereof. Specifically, the guide portion 43 includes a first arc portion 44 and a second arc portion 45. There is a smooth transition between the first arc portion 44 and the second arc portion 45, and the convex directions of the first arc portion 44 and the second arc portion 45 are opposite.

The dimension of the air guide portion 43 along the blade length direction is 0.10-0.20 times, preferably 0.13-0.15 times, the chord length of the short blade 42 .

The impeller structure of a rocket engine turbo pump of the present invention can reduce the vortex at the inlet of the short blade 42 through the design of the guide portion 43, which includes a first arc portion 44 and a second arc portion 45, thereby reducing the pressure pulsation of the pump.

Further, in the axial cross-sectional view, the leading edge portion of the short blade 42 has a third arc portion 46 , and the third arc portion 46 is a part of a circle.

The impeller structure of a rocket engine turbo pump of the present invention is designed so that at least 51% of the leading edge inner diameters/radii of the short blades 42 are unequal, and preferably, the leading edge inner diameters/radii of the short blades 42 are unequal, which can reduce the pressure pulsation of the impeller cavity, reduce the impact of uneven liquid flow at the pump inlet on the impeller, and make the impact of the liquid flow on the impeller uniform, thereby reducing vibration. The design of the guide portion 43, which includes a first arc portion 44 and a second arc portion 45, can reduce the vortex at the inlet of the short blades 42, thereby reducing the pressure pulsation of the pump.

The above-mentioned implementation modes are for explanation of the present invention rather than limitation of the present invention. It is to be understood that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principle and spirit of the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims (3)

1. An impeller structure of a rocket engine turbo pump, comprising a first housing (1), a second housing (2), a third housing (3), a first centrifugal impeller (4), a first spiral inducer (5), a common shaft (6), a second centrifugal impeller (7), a second spiral inducer (8), a mechanical seal (9), and an inlet flow channel, wherein one end of the first housing is connected to the second housing via a connecting piece, and the other end is connected to the third housing via a connecting piece, a first spiral inducer is disposed at an upstream end of the first centrifugal impeller, the first spiral inducer is adjacent to the inlet flow channel, a second spiral inducer is disposed at an upstream end of the second centrifugal impeller, and the first centrifugal impeller, the first spiral inducer, and the second centrifugal impeller are connected to the inlet flow channel. The first centrifugal impeller and the second spiral inducer are respectively installed on the common shaft, a mechanical seal is installed in the first housing and on the outer periphery of the common shaft, the first centrifugal impeller and the second centrifugal impeller are arranged back to back with respect to the mechanical seal, the first pump having the first centrifugal impeller (4) is used to pump cryogenic methane or cryogenic liquid oxygen, and the second pump having the second centrifugal impeller (7) is used to pump cryogenic methane or cryogenic liquid oxygen; the first centrifugal impeller and/or the second centrifugal impeller comprises a rear disc, a front disc, and blades, a plurality of blades are distributed between the rear disc and the front disc along the circumferential direction, the blades comprise long blades (41) and short blades (42), the long blades and the short blades have the same outer diameter, and the plurality of long blades and the plurality of short blades are alternately arranged along the circumferential direction; The invention is characterized in that at least 51% of the short blades (42) have leading edge inner diameters/radii of different sizes; The short blade (42) has a concave surface and a convex surface arranged opposite to each other, and a guide portion (43) is arranged on the front edge of the short blade (42) and on one side of the concave surface; the guide portion (43) comprises a first arc portion (44) and a second arc portion (45); there is no smooth transition between the first arc portion (44) and the front edge of the short blade (42), and there is a smooth transition between the first arc portion and the second arc portion; the convex directions of the first arc portion and the second arc portion are opposite; the dimension of the guide portion (43) along the blade length direction is 0.05-0.15 times the chord length of the short blade (42); In an axial cross-sectional view, the leading edge portion of the short blade (42) has a third arc portion (46), and the third arc portion is a part of a circle. 2. An impeller structure for a rocket engine turbopump as described in claim 1, characterized in that the leading edge inner diameter/radius sizes of each short blade (42) are different. 3. An impeller structure for a rocket engine turbopump as described in claim 2, characterized in that the inner diameter of the leading edge of the short blade (42) is 1.5-2.5 times the inner diameter of the leading edge of the long blade (41).