CN112648226A

CN112648226A - Structure for preventing gas backflow and magnetic suspension type compressor and turbine motor system comprising same

Info

Publication number: CN112648226A
Application number: CN202011532461.5A
Authority: CN
Inventors: 尹成科; 尤志强; 吴文志
Original assignee: Suzhou Suci Intelligent Technology Co ltd
Current assignee: Suzhou Suci Intelligent Technology Co ltd
Priority date: 2020-12-23
Filing date: 2020-12-23
Publication date: 2021-04-13

Abstract

A gas backflow prevention structure and a magnetic suspension type compressor and turbine motor system comprising the gas backflow prevention structure are provided. The structure comprises: the impeller (1), the volute (2), the rotating shaft (3) and the partition plate (4). The impeller (1) is arranged on the rotating shaft (3). And a vortex-shaped bulge (50) is arranged on one surface of the partition plate (4) opposite to the back of the impeller (1). The turbine motor system, the magnetic suspension compressor and the gas backflow prevention structure in the magnetic suspension compressor can effectively prevent high-temperature and high-pressure gas in the motor from flowing back, avoid the problem of overheating inside the motor caused by the backflow of the high-temperature and high-pressure gas, reduce the kinetic energy loss of the gas while providing the sealing property, and improve the working efficiency of equipment.

Description

Structure for preventing gas backflow and magnetic suspension type compressor and turbine motor system comprising same

Technical Field

The embodiment of the invention relates to the field of turbine motor systems, in particular to a gas backflow preventing structure, a magnetic suspension type compressor comprising the gas backflow preventing structure and a turbine motor system.

Background

Radial-flow impellers are widely used in the field of turbine motor systems, including compressors, expanders, pumps for delivering fluids, and the like. Especially in the field of magnetic suspension compressors, compared with axial compressors, the compressor adopting the radial-flow impeller has the advantages of small axial length, large stable working range, simple structure, convenience in manufacturing and the like. When the magnetic suspension type compressor works, the rotating shaft drives the impeller to rotate at a high speed, and gas is sucked from the center of the impeller and flows to the outer edge of the impeller. The impeller works on the gas, and the high-temperature high-pressure gas flows to the outer edge of the impeller. Generally, high-temperature and high-pressure gas enters the volute along the outer edge of the impeller to perform speed reduction and diffusion. Because the impeller and the motor clapboard have a gap, and the central air pressure of the impeller rotating at high speed is very low, high-temperature and high-pressure gas can flow into the machine body from the outer edge of the impeller through the gap. High-temperature and high-pressure gas enters the motor to cause the internal temperature of the motor body to be too high, so that the motor fails.

As described above, the problem that the high-temperature and high-pressure gas flows back into the inside of the motor decreases the working efficiency of the magnetic levitation type compressor and deteriorates the reliability of the magnetic levitation type compressor.

In order to solve the above-mentioned high-temperature and high-pressure gas backflow problem, the prior art widely adopts two methods of labyrinth seal (meaning seal with a plurality of zigzag small chambers between rotating part and fixed part to reduce leakage) and dry gas seal (mainly by adding dynamic pressure groove on the mechanical seal rotating ring and correspondingly arranging an auxiliary system to realize non-contact operation of the seal end face).

Labyrinth seals cannot be completely sealed due to the straight-through effect. It is not suitable for the magnetic suspension compressor with long-time high-speed rotation of the impeller. Further, the leakage amount of the labyrinth seal is positively correlated with the size of the throttle backlash. The smaller the throttling tooth gap is, the better the sealing performance is, and the higher the gas kinetic energy loss is; the larger the throttling tooth clearance is, the poorer the sealing performance is, and the lower the kinetic energy loss of the gas is. Therefore, in order to improve the sealing performance, the throttle backlash needs to be reduced. This increases the kinetic energy loss of the gas and reduces the working efficiency of the magnetic levitation type compressor. And the design of the throttling tooth gap is too small, so that the rotating shaft can rub with the labyrinth seal comb teeth at the critical rotating speed, the throttling comb teeth are broken, the sealing performance is lost, and the failure rate of the magnetic suspension type compressor is increased. If the throttle gap is enlarged, the backflow of the high-temperature and high-pressure gas cannot be prevented.

Dry gas seals have a lower leakage than labyrinth seals, but must have a seal running gas present. After the sealing end face of the dry gas seal is opened, the gap is usually only about 3 mu m, if the sealing gas has particles, scratches can be caused on the end face, the leakage amount is increased, and even the tightness is lost, so that a relatively expensive sealing auxiliary system is needed, and therefore, the overall manufacturing cost is high.

Disclosure of Invention

The embodiment of the invention provides a gas backflow prevention structure, a magnetic suspension type compressor comprising the same and a turbine motor system, aiming at the defects of the prior art, and the structure can prevent high-temperature and high-pressure gas from flowing back into a motor or the turbine motor system to cause damage to the motor and the turbine motor system. The structure for preventing gas backflow and the turbine motor system have the advantages of preventing gas backflow, having small influence on the working efficiency of equipment and even having no influence. And the structure and the system for preventing gas backflow have low manufacturing and maintenance cost and safe and reliable structure.

According to at least one embodiment of the present disclosure, there is provided a structure for preventing gas backflow, including: the vortex-shaped impeller comprises an impeller, a volute, a rotating shaft and a partition plate, wherein a vortex-shaped bulge is arranged on one surface of the partition plate opposite to the back of the impeller (1).

For example, a circular hole is arranged at the center of the partition plate, and the rotating shaft penetrates through the partition plate from the circular hole.

For example, the swirl-shaped protrusion is arranged between the outer circumference of the circular hole and the inner wall of the groove, with the center of the circle of the circular hole as the center.

For example, the swirl-like protrusions are distributed along the circumference of the circular hole.

For example, the swirl-like projection comprises a plurality of projecting strips.

For example, the central angle of the arc of the swirl-like raised stripe is between 0 ° and 90 °.

For example, the distance between the swirl-like projection and the impeller back is 0.1% -3% of the impeller radius.

For example, the shapes of the convex bars of the spiral-shaped protrusions include rectangular convex bars, trapezoidal convex bars, cylindrical convex bars, and triangular cylindrical convex bars.

For example, the swirl-shaped protrusion and the groove may be integrally formed on the partition plate, or the swirl-shaped protrusion may be mounted on the partition plate after being formed and forms the groove with the corresponding side wall of the partition plate to form a detachable structure.

For example, with the detachable structure, the swirl-like protrusion may be fixedly connected to the partition by a fastener.

For example, the swirl-like projections in the grooves comprise at least one of metallic copper, graphite, cobalt-based metal, and non-metallic fibers.

For example, the area of the swirl-like projections is smaller than the area of the non-projecting portions within the grooves.

For example, the swirl-like projections comprise one or more of the same or different projection stripe shapes.

For example, the spiral direction of the swirl-like projection is the same as the spiral direction of the impeller.

For example, the rotational directions of the impeller and the swirl-like projection are both clockwise or counterclockwise.

According to at least one embodiment of the present disclosure, there is provided a magnetic levitation compressor including any one of the structures for preventing gas from flowing back.

For example, the magnetic levitation type compressor further includes: the shell and the motor stator, the structure that prevents gas backflow sets up and is keeping away from motor stator's both ends.

There is also provided, in accordance with at least one embodiment of the present disclosure, a turbine motor system including any of the magnetic levitation type compressors.

Drawings

Fig. 1A is a cross-sectional view of a structure for preventing gas backflow according to an embodiment of the present invention.

FIG. 1B is a partially enlarged view of a structure in the vicinity of the convex portion of FIG. 1;

FIG. 2A is a front view of a separator plate with raised striations of a gas backflow prevention structure in the grooves;

FIG. 2B is a front view of a separator plate with raised striations with two gas backflow prevention structures in the grooves;

FIG. 3 is a schematic view of a structure for preventing gas backflow, in which the protrusions are rectangular protrusions;

FIG. 4 is a schematic view of a structure for preventing gas backflow, in which the protrusions are trapezoidal protrusions;

FIG. 5 is a schematic view of a structure for preventing gas backflow, in which the protrusions are cylindrical protrusions;

FIG. 6 is a schematic view of a structure for preventing gas backflow, in which the protrusions are triangular prism-shaped protrusions;

FIG. 7A is a schematic view showing a detachable structure of a projection of the structure for preventing gas from flowing backward, and

fig. 7B is an enlarged view of a dotted frame portion in fig. 7A.

Fig. 8 is a schematic structural view of a magnetic levitation compressor with a gas backflow preventing structure.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present disclosure, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly. .

Further, the dimensions and sizes of the various elements or portions in the drawings are not reflective of the dimensions and sizes of actual elements or portions, but are merely schematic.

The embodiment of the invention discloses a structure for preventing gas backflow. As shown in fig. 1A-1B, the structure includes: impeller 1, volute 2, shaft 3, and baffle 4.

The gas backflow prevention structure can be applied to turbine motor systems (such as compressors, expanders, pumps for conveying fluids, and the like).

For example, the gas that may flow back is high-temperature and high-pressure gas generated by the rotation of the impeller 1 in the magnetic levitation type compressor.

The temperature and the pressure of the high-temperature and high-pressure gas are relative to the temperature and the pressure of the gas at the inlet of the magnetic suspension type compressor, because the temperature of the gas rises while the pressure of the gas rises for a certain mass of the gas, the temperature and the pressure of the gas are obtained by an ideal gas equation pV = nRT,

where p refers to the pressure of the ideal gas, V is the volume of the ideal gas, n represents the amount of gaseous species, T represents the thermodynamic temperature of the ideal gas, and R is the ideal gas constant.

For example, for a common air compressor, the temperature of air at the inlet of the compressor is about 25 °, and after the air is pressurized by the impeller, the temperature of air at the outlet can reach about 80 °. At this time, the pressure and temperature of the gas at the outlet of 80 ° are raised relative to the pressure and temperature of the gas at the inlet of 25 °, so that the gas at the outlet can be called high-temperature high-pressure gas.

For example, in the case of a water vapor compressor, the temperature of air at the inlet of the compressor is about 80 °, and after the air is pressurized by the impeller, the temperature of air at the outlet of the compressor can reach about 120 °. At this time, the pressure and temperature of the gas at the outlet 120 ° are increased relative to the pressure and temperature of the gas at the inlet 80 °, so that the gas at the outlet can be referred to as high-temperature high-pressure gas. In the embodiment of the invention, the gas at the inlet of the compressor does work through the impeller 1, and the pressure is increased while the temperature is also increased.

Therefore, the high-temperature and high-pressure gas herein refers to the gas after the work of the impeller 1 is performed. For example, the high-temperature and high-pressure gas herein refers to gas which flows into the center of the impeller 1 from the inlet of the compressor and is then thrown to the edge of the impeller 1 by the centrifugal force of the impeller 1.

As shown in fig. 2, a circular hole 30 is formed in the center of the partition plate 4, and the rotating shaft 3 penetrates through the partition plate 4 from the circular hole 30. The outer ring of the round hole 30 is provided with a round groove 40, and the diameter of the round groove 40 is slightly larger than the maximum outer diameter of the impeller 1. The impeller 1 is partially arranged in the groove 40 of the clapboard 4, and the outer edge of the impeller and the groove 40 form a gas return channel 10. The groove 40 is provided with a swirl-like projection 50. The spiral protrusions 50 are uniformly distributed along the circumference of the circular hole 30 from the center of the circular hole 30 and connected to the inner diameter of the circular groove 40.

With reference to fig. 1A-1B and fig. 2, when the impeller rotates at a high speed, the gas at the back of the impeller flows along the spiral-shaped protrusions 50 on the grooves 40 from the center of the back of the impeller to the edge of the back of the impeller, flows to the outside of the motor through the gas return passage 10, and forms a high pressure zone at the gas return passage 10.

For example, the high-pressure gas flowing from the center of the back of the impeller to the outer edge of the back of the impeller can prevent the high-temperature high-pressure gas generated by the rotation of the front of the impeller from flowing back into the interior of the motor in combination with the centrifugal force generated by the high-speed rotation of the impeller to the outside of the motor.

The height of the spiral protrusions 50 on the groove 40 can be adjusted by combining the distance between the impeller back 11 and the bottom of the groove, and the spiral protrusions 50 can perform a sealing function by controlling the distance 20 between the spiral protrusions 50 and the impeller back 11, wherein the length of the distance 20 is only shown schematically, for example, as shown in fig. 1B.

The embodiment of the present disclosure also provides a magnetic levitation type compressor including the gas backflow prevention structure. In one embodiment, when the magnetic levitation type compressor is operated, the pressure of the gas flowing from the center of the back of the impeller to the outer edge of the back of the impeller can be changed by adjusting various parameters of the swirl-shaped protrusion 50 (e.g., the number of the protrusion strips of the swirl-shaped protrusion 50, the number of the arc, etc.). The centrifugal force action of the edge of the impeller is combined, so that the high-temperature and high-pressure gas generated on the front surface of the impeller can be completely prevented from flowing back. Therefore, the magnetic suspension type compressor of the embodiment of the invention can not generate kinetic energy loss of high-pressure gas due to sealing problems. For example, the circular arc has a central angle in the range of 0 ° to 90 °.

For example, the spiral direction of the swirl-like projection is the same as the spiral direction of the impeller. For example, if the impeller is clockwise, then the swirl direction of the swirl-like projections is also clockwise, or both are counterclockwise.

For example, the distance between the swirl-like projections 50 and the impeller back 11 is 0.1% to 3% of the impeller radius.

Further, for example, in consideration of the case where high-temperature and high-pressure gas generated at the front surface of the impeller enters the interior of the motor through the gas return passage 10, the swirl-like projection 50 has a sealing function (for example, a function of pushing the gas outward is generated by the rotation function of the impeller and a swirl-like structure opposite to the rotation direction of the impeller), and the space between the stripes of the swirl-like projection 50 is large, so that the loss of kinetic energy of the gas while preventing the high-pressure gas from flowing back is small compared to a labyrinth seal.

Further, for example, as shown in fig. 3, 4, 5, and 6, the shape of the swirl-shaped protrusion 50 may be designed as a rectangular protrusion, a circular protrusion, a cylindrical protrusion, a triangular pillar protrusion, and the like, but embodiments of the present disclosure are not limited thereto.

Further, for example, the swirl-like projections 50 may comprise one or more projection strips having one or more different projection shapes. For example, as shown in fig. 2(B), a second protrusion strip 52 may be provided in addition to the first protrusion strip 51, and so on, and a third protrusion strip and a fourth protrusion strip may be added to the conventional spiral protrusion strip. Embodiments of the present disclosure are not limited thereto.

Further, for example, the spiral protrusion 50 and the groove 40 may be integrally formed on the partition plate 4, or as shown in fig. 7A to 7B, the spiral protrusion 50 and the groove 40 may be integrally formed and then mounted on the partition plate 4 to form a detachable structure. For example, the spiral protrusion 50 is formed on a base plate, the minimum thickness of the base plate with the protrusion is smaller than the thickness of the partition plate 4, a notch is formed on the bottom of the partition plate, the thickness of the base plate of the protrusion is equal to that of the notch, and the base plate of the protrusion is fixedly connected with the bottom of the partition plate 4 at the notch by a fastener to naturally form the circular groove 40, so that the detachable structure is formed.

Further, for example, the swirl-like protrusion 50 material within the groove 40 may be metallic copper, graphite, cobalt-based metal, or non-metallic fibers. Embodiments of the present disclosure are not limited thereto.

As shown in fig. 8, the magnetic levitation compressor may further include: a housing 5, and a motor stator 6. For example, in the magnetic levitation type compressor shown in fig. 8, two structures for preventing backflow of high-temperature and high-pressure gas, each of which includes a vortex-like projection, are provided.

Embodiments of the present invention also provide a turbine motor system including any of the magnetic levitation type compressors.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention.

Claims

1. A structure for preventing gas backflow, comprising: the vortex type impeller comprises an impeller (1), a volute (2), a rotating shaft (3) and a partition plate (4), wherein a vortex-shaped bulge (50) is arranged on one surface of the partition plate (4) opposite to the back of the impeller (1).

2. The structure according to claim 1, wherein a circular hole (30) is provided at the center of the partition plate (4), and the rotating shaft (3) passes through the partition plate (4) from the circular hole (30).

3. The structure of claim 2, wherein the swirl-like projection (50) is arranged between the outer circumference of the circular hole (30) and the inner wall of the recess (40), centered on the center of the circular hole (30).

4. The structure of claim 2, wherein the swirl-like protrusions (50) are distributed along the circumference of the circular hole (30).

5. The structure of claim 1, wherein the swirl-like projection (50) comprises a plurality of projection bars.

6. The structure according to claim 1, wherein the central angle of the circular arc of the swirl-like projection (50) stripe is between 0 ° and 90 °.

7. A structure according to claim 3, wherein the distance of the swirl-like projection (50) from the impeller back (11) is 0.1-3% of the impeller radius.

8. The structure of claim 1, wherein the raised bars of the swirl-like projection (50) comprise rectangular, trapezoidal, cylindrical, triangular-cylindrical raised bars.

9. The structure of claim 1, wherein the swirl-shaped protrusion (50) can be integrally formed on the partition (4) together with the groove (40), or the swirl-shaped protrusion (50) can be mounted on the partition (4) after being formed and forms the groove (40) together with the corresponding side wall of the partition (4), thereby forming a detachable structure.

10. The structure of claim 9, wherein, in the detachable configuration, the swirl-like projection (50) is fixedly connected to the partition (4) by means of a fastening element.

11. The structure of claim 1, wherein the swirl-like projections (50) within the grooves (40) comprise at least one of metallic copper, graphite, cobalt-based metal, and non-metallic fibers.

12. The structure of claim 1, wherein the area of the swirl-like projection (50) is smaller than the area of the non-projecting portion within the groove (40).

13. The structure of claim 1, wherein the swirl-like projections (50) comprise one or more of the same or different projection stripe shapes.

14. The structure according to claim 1, wherein the swirl-like protrusions (50) have the same direction of rotation as the impeller (1).

15. The structure according to claim 14, wherein the handedness of the impeller (1) and of the swirl-like projection (50) is either clockwise or counter-clockwise.

16. A magnetic levitation type compressor comprising the gas backflow preventing structure as recited in any one of claims 1 to 15.

17. The compressor of claim 16, further comprising: the gas backflow prevention device comprises a shell (5) and a motor stator (6), wherein the gas backflow prevention structure is arranged at two ends of the motor stator (6).

18. A turbine motor system comprising the magnetically levitated compressor of claim 16.