CN112746904A

CN112746904A - Micro gas turbine

Info

Publication number: CN112746904A
Application number: CN202011552727.2A
Authority: CN
Inventors: 陶智; 余明星; 王开
Original assignee: Beihang University Sichuan International Center For Innovation In Western China Co ltd
Current assignee: Beihang University Sichuan International Center For Innovation In Western China Co ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-05-04

Abstract

The invention provides a micro gas turbine, which comprises a shell and a rotating shaft, wherein the shell is provided with a plurality of grooves; the compressor impeller is positioned in the shell and sleeved outside the rotating shaft, the diffuser is connected with the compressor impeller and sleeved on the rotating shaft, the guider is arranged on one side of the diffuser, away from the compressor impeller, and the turbine is connected with the guider and sleeved on the rotating shaft, and the turbine and the compressor impeller are arranged at intervals; a gas circulation flow channel is formed among the compressor impeller, the diffuser, the guider and the turbine and the shell; the diffuser sequentially comprises a vaneless diffusion section, a radial diffusion section and an axial diffusion section along the flow direction of the flow passage so as to increase the pressure ratio of the inlet and the outlet of the flow passage. Through the mode, the compressor impeller and the turbine are arranged at intervals, so that heat conduction from the turbine side to the compressor impeller side can be reduced, and the diffuser is provided with the plurality of diffuser sections to further increase the system pressure ratio, so that the efficiency of the whole machine is improved.

Description

Micro gas turbine

Technical Field

The invention relates to the technical field of micro gas turbines, in particular to a micro gas turbine.

Background

Gas turbines are the highest end product of the energy power equipment field and represent the highest level of skill in the equipment manufacturing industry. The micro gas turbine is widely applied to distributed power generation, the generated power capacity of the micro gas turbine is usually within hundreds of kilowatts, and the micro gas turbine has the characteristics of high-speed operation, small volume, simple operation, convenient installation and the like, and has good market demand.

In a micro gas turbine, a compressor and a turbine are important core components thereof, and one of the most important components in the compressor is a compressor wheel, because the centrifugal compressor mainly applies work to the gas working medium through centrifugal force, high-pressure air enters the combustion chamber to be mixed with fuel and combusted, so that the gas with high temperature and high pressure enters the turbine and pushes the blades to expand and do work to complete a complete working cycle of the micro gas turbine, the layout mode of the compressor impeller and the turbine is closely related to the circulation of gas, the circulation of the gas is related to the conversion efficiency of the gas turbine, if the existing turbine and the impeller of the compressor are closely connected, the heat of the turbine is easily conducted to the compressor, the service life of the compressor material is reduced, if the distance is too far, the whole machine is oversize, and great inconvenience is brought to later use and maintenance of the gas turbine.

Disclosure of Invention

The embodiment of the invention provides a micro gas turbine, which is used for solving the technical problem that the gas turbine in the prior art is low in use and maintenance efficiency.

An embodiment of the present invention provides a micro gas turbine, including: a housing;

a rotating shaft;

the compressor impeller is positioned in the shell and sleeved outside the rotating shaft, the diffuser is connected with the compressor impeller and sleeved on the rotating shaft, the guider is arranged on one side of the diffuser, which is far away from the compressor impeller, and the turbine is connected with the guider and sleeved on the rotating shaft, and the turbine and the compressor impeller are arranged at intervals;

a flow passage for gas circulation is formed among the compressor impeller, the diffuser, the guider, the turbine and the shell; wherein the content of the first and second substances,

the diffuser sequentially comprises a vaneless diffusion section, a radial diffusion section and an axial diffusion section along the flowing direction of the flow channel so as to increase the pressure ratio of the inlet and the outlet of the flow channel.

According to the micro gas turbine provided by the embodiment of the invention, one side of the diffuser, which is close to the vaneless diffuser section, is a diffuser inlet end, and one side of the diffuser, which is close to the axial diffuser section, is a diffuser outlet end;

the circumferential dimension of the diffuser inlet end is greater than the circumferential dimension of the diffuser outlet end.

According to the micro gas turbine provided by the embodiment of the invention, the ratio of the radial dimension of the flow passage corresponding to the outlet end of the diffuser to the radial dimension of the flow passage corresponding to the inlet end of the diffuser is 0.85-0.95.

According to the micro gas turbine provided by the embodiment of the invention, the bladeless diffuser section comprises a bladeless inlet end and a bladeless outlet end, and the ratio of the radius from the bladeless outlet end to the axis of the rotating shaft to the radius from the bladeless inlet end to the axis of the rotating shaft is 1.07-1.15.

According to one embodiment of the invention, the radial diffuser section comprises a radial inlet end and a radial outlet end;

the ratio of the distance from the flow channel corresponding to the axial diffuser to the rotating shaft to the distance from the radial inlet end of the radial diffuser section to the rotating shaft is 1.2-1.6.

According to the micro gas turbine provided by the embodiment of the invention, the radial diffusion section and the axial diffusion section are arranged at an included angle;

the diffuser is also provided with a turning section between the radial diffusion section and the axial diffusion section.

According to the micro gas turbine provided by the embodiment of the invention, the radial diffusion section is arranged perpendicular to the axial diffusion section, so that the extending direction of the radial diffusion section is arranged perpendicular to the axis of the rotating shaft, and the extending direction of the axial diffusion section is arranged parallel to the axis of the rotating shaft.

According to the micro gas turbine of one embodiment of the invention, the compressor impeller is a centrifugal impeller and at least one large blade and at least one small blade are arranged on the compressor impeller;

the turbine is a centripetal turbine, and at least one turbine blade is arranged on the turbine.

According to the micro gas turbine of one embodiment of the invention, a distance ring and a comb-tooth ring are arranged between the compressor impeller and the turbine, and a bearing is further arranged between the distance ring and the comb-tooth ring to separate the compressor impeller and the turbine.

According to the micro gas turbine provided by the embodiment of the invention, a combustion chamber is further arranged on one side of the turbine, which is far away from the compressor impeller, and the flow passage is communicated with the combustion chamber.

According to the micro gas turbine provided by the embodiment of the invention, the impeller of the gas compressor and the turbine are arranged at intervals, so that the heat transfer from one side of the turbine to one side of the gas compressor can be reduced, the efficiency of the gas compressor is ensured, and the diffuser can be provided with the vaneless diffusion section, the radial diffusion section and the axial diffusion section, so that the pressure ratio is further increased, and the efficiency of the micro gas turbine is further improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

FIG. 1 is a schematic view of a micro gas turbine according to an embodiment of the present invention;

FIG. 2 is a schematic view of a compressor wheel of the micro gas turbine shown in FIG. 1;

FIG. 3 is a cross-sectional view taken at A-A of FIG. 2;

FIG. 4 is a schematic view of a diffuser in the micro gas turbine shown in FIG. 1;

FIG. 5 is a cross-sectional view taken at B-B of FIG. 4;

FIG. 6 is a schematic view of the structure shown in FIG. 5 at Q;

FIG. 7 is a schematic view of a pilot assembly in the micro gas turbine shown in FIG. 1;

FIG. 8 is a cross-sectional view taken at C-C of FIG. 7;

FIG. 9 is a schematic view of the turbine in the micro gas turbine shown in FIG. 1;

FIG. 10 is a cross-sectional view taken at D-D of FIG. 9;

reference numerals:

10: a rotating shaft; 20: an air compressor impeller; 30: a diffuser;

310: a vaneless diffusion section; 3110: a bladeless inlet end; 3120: a bladeless outlet end;

320: a radial diffuser section; 3210: a radial inlet end; 3220: a radial outlet end;

330: an axial diffuser section; 340: a diffuser inlet end; 350: a diffuser outlet end;

360: a turning section; 40: a guide; 50: a turbine;

60: a housing; 70: a flow channel; 810: a distance ring;

820: a grate ring; 830: a bearing; 90: a combustion chamber.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "comprises" and "comprising," and any variations thereof, in the embodiments of the present application, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or may alternatively include other components or elements inherent to such process, method, article, or apparatus.

Referring now to fig. 1, fig. 1 is a schematic structural view of an embodiment of a micro gas turbine according to the present invention. The invention provides a micro gas turbine, which comprises a shell 60 and a rotating shaft 10; the compressor impeller 20 is positioned in the shell 60 and sleeved outside the rotating shaft 10, the diffuser 30 is connected with the compressor impeller 20 and sleeved on the rotating shaft 10, the guider 40 is arranged on one side of the diffuser 30 far away from the compressor impeller 20, the turbine 50 is connected with the guider 40 and sleeved on the rotating shaft 10, and the turbine 50 and the compressor impeller 20 are arranged at intervals. A flow passage 70 for gas to flow is formed between the compressor impeller 20, the diffuser 30, the guider 40, the turbine 50 and the casing 60; the diffuser 30 includes a vaneless diffuser section 310, a radial diffuser section 320, and an axial diffuser section 330 in sequence along the flow direction of the flow passage 70 to increase the inlet-outlet pressure ratio of the flow passage 70. It should be noted that the micro gas engine includes a compressor and a turbine 50, and the compressor includes a compressor impeller 20, and when the compressor and the turbine 50 are installed, in an embodiment of the present invention, the compressor and the turbine 50 are installed back to back, so that the installation between the compressor and the turbine 50 is more compact, and the compressor and the turbine 50 are spaced apart, so that heat on one side of the turbine 50 is not largely conducted to one side of the compressor, thereby reducing heat conduction efficiency. The diffuser 30 includes a vaneless diffuser section 310, a radial diffuser section 320, and an axial diffuser section 330, so that the pressure ratio can be increased when the gas flowing through the flow passage 70 flows through each diffuser section, thereby improving the efficiency of the whole machine. It can be understood that, because the compressor wheel 20 and the turbine wheel 50 are spaced apart from each other, and the diffuser 30 has a longer transverse extension, the axial diffuser section 330 can be disposed in the direction in which the diffuser 30 is flush with the rotating shaft 10, thereby increasing the inlet-outlet pressure ratio of the flow passage 70.

With continued reference to fig. 2 and 3, fig. 2 is a schematic view of a compressor wheel in the micro gas turbine shown in fig. 1; fig. 3 is a cross-sectional view taken at a-a shown in fig. 2. The compressor wheel 20 is obtained with a reduced circumferential dimension. Referring further to fig. 4 and 5, fig. 4 is a schematic structural view of a diffuser in the micro gas turbine shown in fig. 1; fig. 5 is a cross-sectional view at B-B shown in fig. 4. The diffusion is at least partially arranged to overlap the larger circumferential dimension of the compressor wheel 20 and at least partially arranged around the circumference of the compressor wheel 20. The housing 60 may then form a flow path 70 with the compressor wheel 20 and the diffuser 30 to allow gas flow.

In an embodiment of the present invention, the gas enters the flow channel 70 from the side of the compressor wheel 20 away from the turbine wheel 50, and the size of the gas flow path before the vaneless diffuser section 310 is reduced, while the size of the flow channel 70 at the vaneless diffuser section 310 and the radial diffuser section 320 is consistent, and the size of the axial diffuser section 330 is inconsistent with the size of the vaneless diffuser section 310 and the radial diffuser section 320, for the following description.

Specifically, the diffuser 30 has a diffuser inlet end 340 on the side near the vaneless diffuser section 310 and a diffuser outlet end 350 on the side near the axial diffuser section 330; the circumferential dimension of the diffuser inlet end 340 is greater than the circumferential dimension of the diffuser outlet end 350. That is, the diffuser 30 has a large flow cross section near the upstream of the flow passage 70 and a small flow cross section near the downstream of the flow passage 70, thereby facilitating the flow of the gas compressor wheel 20 side toward the turbine wheel 50 side.

Referring to fig. 6, fig. 6 is a schematic view of the structure at Q shown in fig. 5. In one embodiment of the present invention, the ratio of the radial dimension of the flow passage 70 at the diffuser outlet end 350 to the radial dimension of the flow passage 70 at the diffuser inlet end 340 is 0.85-0.95. In one embodiment of the present invention, the ratio of the radial dimension of the flow passage 70 corresponding to the diffuser outlet end 350 to the radial dimension of the flow passage 70 corresponding to the diffuser inlet end 340 is preferably 0.9. I.e. corresponding to a ratio of D2 to D1 of 0.9 as shown in fig. 6.

With continued reference to fig. 5, in one embodiment of the present invention, the vaneless diffuser 310 includes a vaneless inlet 3110 and a vaneless outlet 3120, and the ratio of the radius from the vaneless outlet 3120 to the axis of the rotating shaft 10 to the radius from the vaneless inlet 3110 to the axis of the rotating shaft 10 is 1.07-1.15. In one embodiment of the present invention, the ratio of the radius from the vaneless outlet port 3120 to the axis of the shaft 10 to the radius from the vaneless inlet port 3110 to the axis of the shaft 10 is preferably 1.11, i.e., the ratio of D3 to D2 shown in fig. 5 is 1.11.

The radial diffuser section 320 includes a radial inlet end 3210 and a radial outlet end 3220; in one embodiment of the present invention, the ratio of the distance from the flow passage 70 of the axial diffuser 30 to the rotation shaft 10 to the distance from the radial inlet end 3210 of the radial diffuser section 320 to the rotation shaft 10 is 1.2-1.6. In one embodiment of the present invention, the ratio of the distance from the corresponding flow passage 70 of the axial diffuser 30 to the rotating shaft 10 to the distance from the radial inlet end 3210 of the radial diffuser section 320 to the rotating shaft 10 is preferably 1.4. Also corresponding to a ratio of D5 to D3 of fig. 5 of 1.4.

Referring to fig. 1, the radial diffusion section 320 and the axial diffusion section 330 form an included angle therebetween; diffuser 30 also has a turnaround section 360 between radial diffuser section 320 and axial diffuser section 330. In an embodiment of the present invention, the radial diffuser section 320 is disposed perpendicular to the axial diffuser section 330, such that the extending direction of the radial diffuser section 320 is disposed perpendicular to the axis of the rotating shaft 10, and the extending direction of the axial diffuser section 330 is disposed parallel to the axis of the rotating shaft 10. It will be appreciated that the compressor wheel 20 is spaced from the turbine wheel 50 by a distance corresponding to the size of the diffuser 30 at the axial diffuser section 330.

With continued reference to fig. 2 and 3, the compressor impeller 20 is a centrifugal impeller, and the compressor impeller 20 is provided with a plurality of large blades and a plurality of small blades; the turbine 50 is a centripetal turbine, and a plurality of blades are provided on the turbine 50. In an embodiment of the invention, the specific parameters of the micro gas engine are as follows: the design flow is 3.12kg/s, the design total pressure ratio is 4.3, the design point efficiency is 82%, the design rotation speed is 31500rpm, and the stall margin under the design rotation speed is 12.8%. The flow rate of the corresponding turbine 50 is 3.1881kg/s, the expansion ratio is 3.8682, the efficiency is 0.83, the inlet total temperature and the inlet total pressure of the turbine 50 parts are 1203.15K and 410.0323kpa respectively, and the rotating speed is 31500 r/min. The compressor wheel 20 is thus provided with 9 large blades and 9 small blades. The number of blades provided to the turbine 50 is 24. And the blade profiles of the blades on the compressor wheel 20 and the turbine wheel 50 adopt a Bessel blade angle distribution, thereby enabling the diffuser 30 to have higher peak efficiency and stable working range.

In an embodiment of the present invention, a distance ring 810 and a comb ring 820 are disposed between the compressor wheel 20 and the turbine wheel 50, and a bearing 830 is further disposed between the distance ring 810 and the comb ring 820 to separate the compressor wheel 20 and the turbine wheel 50.

With continuing reference to FIGS. 7, 8, 9 and 10, FIG. 7 is a schematic view of a pilot assembly of the micro gas turbine engine of FIG. 1; FIG. 8 is a cross-sectional view taken at C-C of FIG. 7; FIG. 9 is a schematic view of the turbine in the micro gas turbine shown in FIG. 1; fig. 10 is a cross-sectional view taken at D-D of fig. 9. It should be noted that a combustion chamber is further provided on a side of the turbine 50 away from the compressor wheel 20, and the flow passage 70 is communicated with the combustion chamber. The gas enters the compressor impeller 20 side to be compressed and then flows through the diffuser 30 to the combustion chamber to be combusted and processed, the heat energy is converted into mechanical energy, the scattered gas flow is enabled to circulate along one direction under the action of the guider 40, the turbine 50 is driven to rotate, the turbine 50 drives the rotating shaft 10 to rotate, on one hand, the compressor impeller 20 is driven to rotate, the compression efficiency is improved, and on the other hand, the gear box and the generator arranged at the rear section are driven to work and generate electricity.

In summary, the diffuser 30 is sequentially provided with the vaneless diffuser section 310, the radial diffuser section 320 and the axial diffuser section 330 along the flow passage 70, so that the system pressure ratio can be increased, and the compressor and the turbine 50 are arranged at intervals, so that high temperature on one side of the turbine 50 is not greatly transmitted to one side of the compressor, and further heat conduction from the turbine 50 to one side of the compressor is reduced, so that each part in the compressor does not need to adopt a material with better heat resistance to prolong the service life, and further the cost is saved.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A micro gas turbine, comprising:

a housing;

a rotating shaft;

2. The micro gas turbine according to claim 1, wherein a diffuser inlet end is on a side of the diffuser adjacent to the vaneless diffuser section and a diffuser outlet end is on a side of the diffuser adjacent to the axial diffuser section;

3. The micro gas turbine of claim 2, wherein a ratio of a radial dimension of the flow passage corresponding to the diffuser outlet end to a radial dimension of the flow passage corresponding to the diffuser inlet end is between 0.85 and 0.95.

4. The micro gas turbine according to claim 3, wherein the vaneless diffuser includes a vaneless inlet end and a vaneless outlet end, and a ratio of a radius from the vaneless outlet end to an axis of the rotating shaft to a radius from the vaneless inlet end to the axis of the rotating shaft is 1.07-1.15.

5. The micro gas turbine of claim 4, wherein the radial diffuser section includes a radial inlet end and a radial outlet end;

6. The micro gas turbine according to claim 5, wherein the radial diffuser section is disposed at an angle to the axial diffuser section;

7. The micro gas turbine according to claim 6, wherein the radial diffuser section is disposed perpendicular to the axial diffuser section such that an extending direction of the radial diffuser section is disposed perpendicular to an axis of the rotating shaft and an extending direction of the axial diffuser section is disposed parallel to the axis of the rotating shaft.

8. The micro gas turbine according to claim 1, wherein the compressor wheel is a centrifugal wheel and at least one large blade and at least one small blade are provided on the compressor wheel;

9. The micro gas turbine as set forth in claim 1, wherein a distance ring and a comb-tooth ring are provided between said compressor wheel and said turbine wheel, and a bearing is further provided between said distance ring and said comb-tooth ring to separate said compressor wheel and said turbine wheel.

10. The micro gas turbine according to claim 1, wherein a combustion chamber is further provided on a side of the turbine remote from the compressor wheel, and the flow passage communicates with the combustion chamber.