Blade profile tube nozzle for gas turbine

Abstract

An impeller tube-type nozzle for a gas turbine, with an inlet section, a retraction section and an outlet section. The inlet section is a section of annular channel, the retraction section comprises multiple gas flow channels separated by multiple blades, each gas flow channel is encircled by an outer peripheral wall face, an inner peripheral wall face, a suction face of one of two adjacent blades and a pressure face of the other of the two adjacent blades, and inlets of the gas flow channels have a fan-shaped cross section. For each gas flow channel, along the direction of gas flow from the inlet of the gas flow channel to the outlet the fan-shaped cross section gradually smoothly transitions into a circular cross section.

Claims

1. A blade profile tube nozzle for a gas turbine, comprising: an inlet section which is an annular passage; a tapered section which comprises a plurality of airflow circulation passages separated by a plurality of blades; and an outlet section, comprising circular tubes respectively connected to the outlets of the airflow circulation passages correspondingly and with the diameter not changing along the axis; wherein the inlet section, the tapered section and the outlet section are sequentially connected in a flow direction of airflow, and each of the airflow circulation passages is enclosed by an outer circumferential wall face, an inner circumferential wall face, a suction face of one of two adjacent blades and a pressure face of the other one of the two adjacent blades, and cross-section of an inlet of the airflow circulation passage is fan-shaped, and from the flow direction of the airflow, with regard to each of the airflow circulation passages, the fan-shaped cross-section gradually and smoothly transitions to a circular cross-section from the inlet to an outlet of the airflow circulation passage, wherein the two adjacent blades are provided as a turning point of a dominant airflow in a circumferential direction of the nozzle, and the outer circumferential wall face and the inner circumferential wall face are provided as a turning point of the dominant airflow in a radial direction of the nozzle.

2. A blade profile tube nozzle for a gas turbine, comprising: an inlet section which is an annular passage; a tapered section which comprises a plurality of airflow circulation passages separated by a plurality of blades; and an outlet section, comprising circular tubes respectively connected to the outlets of the airflow circulation passages correspondingly and with the diameter not changing along the axis; wherein the inlet section, the tapered section and the outlet section are sequentially connected in a flow direction of airflow, and each of the airflow circulation passages is enclosed by an outer circumferential wall face, an inner circumferential wall face, a suction face of one of two adjacent blades and a pressure face of the other one of the two adjacent blades, and cross-section of an inlet of the airflow circulation passage is fan-shaped, and from the flow direction of the airflow, with regard to each of the airflow circulation passages, the fan-shaped cross-section gradually and smoothly transitions to a circular cross-section from the inlet to an outlet of the airflow circulation passage, wherein the two adjacent blades are provided as a turning point of a dominant airflow in a circumferential direction of the nozzle, and the outer circumferential wall face and the inner circumferential wall face are provided as a turning point of the dominant airflow in a radial direction of the nozzle, wherein the outlet section is a spiral tube with a spiral line as an axis, the spiral line penetrates through the center of the circular cross-section, and a tangent line of the spiral line at the center of the circular cross-section is parallel to a normal vector of the circular cross-section.

3. The blade profile tube nozzle of claim 2, wherein an axial distance between the center of the circular cross-section and an outlet of the circular tube along the axis of the circular tube is an axial length of the circular tube, being between 0.1 and 5 times the diameter of the circular cross-section.

4. The blade profile tube nozzle of claim 1, wherein the outlet section is a straight tube with a straight line as an axis, and the axis penetrates through the center of the circular cross-section and is parallel to a normal vector of the circular cross-section.

5. The blade profile tube nozzle of claim 1, wherein the inlet section is an annular passage.

6. The blade profile tube nozzle of claim 2, wherein the circular tube takes a projection line of one straight line as the axis, the projection line is the projection of the straight line on a revolving face on which the center of an initial circular cross-section of the circular tube is located, and the revolving face is a cylindrical face with a radius defined by a vertical line from the center of the initial circular cross-section to an axis of the blade profile tube nozzle and is stretched parallel to the axial direction of blade profile tube nozzle.

7. The blade profile tube nozzle of claim 2, wherein the blade profile tube nozzle is used in a pre-swirl cooling system in a high pressure turbine of an aviation engine, and cool air is turned and then sent to a blade root of a high-pressure turbine rotor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above-mentioned and other features, properties and advantages of the present disclosure will become more apparent from the following description of embodiments with reference to the accompanying drawings, in which:

(2) FIG. 1 is a perspective view of a blade profile tube nozzle of the present disclosure, wherein an outlet side thereof is shown in a transverse cross-section.

(3) FIG. 2 is a front view of the blade profile tube nozzle of the present disclosure, wherein an inlet side thereof is shown in the transverse cross-section.

(4) FIG. 3 is a rear view of the blade profile tube nozzle of the present disclosure, wherein the outlet side thereof is shown in the transverse cross-section.

(5) FIG. 4 is a lateral half cross-sectional view of the blade profile tube nozzle of the present disclosure.

(6) FIG. 5 is a side view of a split body of a revolving face of 50% of the blade height of the blade profile tube nozzle of the present disclosure.

(7) FIG. 6 is a perspective view of the split body of the revolving face of 50% of the blade height of the blade profile tube nozzle of the present disclosure.

(8) FIG. 7 is a perspective view of the split body of the revolving face of 50% of the blade height of the blade profile tube nozzle of a further embodiment of the present disclosure.

(9) FIG. 8 is a perspective view of the split body of the revolving face of 50% of the blade height of the blade profile tube nozzle of a still further embodiment of the present disclosure.

DETAILED DESCRIPTION

(10) The present disclosure will be further described below in conjunction with particular embodiments and the accompanying drawings, and more details are explained in the following description for the ease of fully understanding the present disclosure; however, the present disclosure can obviously be implemented in various different manners than that described herein, a person skilled in the art can make a similar extension and deduction without departing from the connotation of the present disclosure according to the practical applications, and therefore, the scope of protection of the present disclosure should not be limited to the content of the particular embodiments herein.

(11) It should be noted that the drawings are merely used as examples, and are not necessarily drawn to scale, and should not be taken as a limitation to the actually claimed scope of protection of the present disclosure.

(12) FIGS. 1-6 show an embodiment of the present disclosure. FIG. 7 shows a further embodiment of the present disclosure. FIG. 8 shows a still further embodiment of the present disclosure.

(13) As shown in FIGS. 1-6, in an embodiment of the present disclosure, a blade profile tube nozzle 101 comprises an outer circumferential lateral wall 110, an inner circumferential lateral wall 111, a plurality of blades 105 and a plurality of circular tubes 104. The outer circumferential lateral wall 110 and the inner circumferential lateral wall 111 are annular members, the inner circumferential lateral wall is located in the outer circumferential lateral wall 110, the plurality of blades 105 are connected and fixed between the outer circumferential lateral wall 110 and the inner circumferential lateral wall 111, and the plurality of circular tubes 104 are also connected and fixed between the outer circumferential lateral wall 110 and the inner circumferential lateral wall 111. The blade profile of the blade 105 can be provided based on the blade of the existing blade type pre-swirl nozzle, and comprises a leading edge, a trailing edge, a pressure face, a suction face, a base end and a top end. The base end is connected and fixed to an outer circumferential face of the inner circumferential lateral wall 111, the top end is connected and fixed to an inner circumferential face of the outer circumferential lateral wall 110, the leading edge is located at an inlet of an after-mentioned airflow circulation passage, and the trailing edge is located at an outlet of the airflow circulation passage.

(14) The blade profile tube nozzle 101 comprises an inlet section 108, a tapered section 107 and an outlet section 106. A preferred entity type of the blade profile tube nozzle 101 can be a casting monomer, and the inlet section 108, the tapered section 107 and the outlet section 106 can be the description of different geometrical positions of the casting monomer. Smooth transition between the inlet section 108 and the outlet section 106 is achieved relying on the tapered section 107, thereby forming a complete and continuous circulation passage. The inlet section 108 is an annular passage defined between the outer circumferential lateral wall 110 and the inner circumferential lateral wall 111, and can be used for mounting the blade profile tube nozzle 101 on an outer wall of a plenum in a combustion chamber. The tapered section 107 is enclosed together by the outer circumferential lateral wall 110, the inner circumferential lateral wall 111 and the plurality of blades 105, wherein an airflow circulation passage is enclosed together by two adjacent blades 105, an inner wall face of the outer circumferential lateral wall 110, and an outer wall face of the inner circumferential lateral wall 111, and a plurality of airflow circulation passages are distributed in the whole circumferential direction of the blade profile tube nozzle 101. In the following, one airflow circulation passage is illustrated as an example, and the description thereof is also suitable for other airflow circulation passages. As shown in FIG. 2, the inlet 102 of the airflow circulation passage is fan-shaped, here “fan shape” can be understood as a shape formed by the intersection of an arc defined by the outer circumferential lateral wall 110 and the inner circumferential lateral wall 111 with a straight line defined by the suction face 112 of one blade 105 and a straight line defined by the pressure face 113 of the adjacent blade.

(15) As shown in FIG. 4, the outlet of the airflow circulation passage is a circular cross-section 103.

(16) As shown in FIGS. 1-6, for one airflow circulation passage, from the flow direction of the airflow, the shape from the inlet 102 to the outlet 103 tapers. On the one hand, the distance between the outer circumferential lateral wall 110 and the inner circumferential lateral wall 111 gradually decreases, on the other hand, the distance between the suction face 112 and the pressure face 113 which are opposite each other also gradually decreases, and the shape of the cross-section of the airflow passage tapers to a circular shape from the fan shape. The blade 105 is configured as a turning point of the airflow of a dominant airflow circulation passage in the circumferential direction of the blade profile tube nozzle 101, and the outer circumferential lateral wall 110 and the inner circumferential lateral wall 111 are configured as a turning point of the dominant airflow in a radius direction of the blade profile tube nozzle 101.

(17) As shown in FIG. 5 and FIG. 6, corresponding to each airflow circulation passage, the outlet section 106 provides a circular tube 104 with the diameter not changing along the axis, wherein the circular tube 104 takes a spiral line 109 as the axis, and the spiral line 109 penetrates through the center of the circular cross-section 103. A tangent line of the spiral line 109 at the center of the circular cross-section 103 is parallel to a normal vector of the circular cross-section 103.

(18) An axial distance between the center of the circular cross-section 103 and the outlet of the circular tube 104 is an axial length of the circular tube 104 and can be between 0.1 and 5 times the diameter of the circular cross-section 103.

(19) The number of the blades of the tapered section 107 can be 8-40, and in the embodiment shown in the FIG. 26 blades 105 are provided.

(20) According to the preceding embodiment, the blade profiles of two adjacent blades 105 are used for controlling the cross-section of the fan-shaped flow passage such that same smoothly tapers to the shape of a circular tube, and a section of circular tube 104 is kept until to the outlet of the nozzle. The diameter of the circular tube 104 does not change along the axis, thus realizing a new type of blade profile tube pre-swirl nozzle designed by the combination of the blade 105 and the circular tube 104. The blade 105 turns the airflow with low aerodynamic loss, and the circular tube 104 can stabilize an outlet direction of the airflow, thereby achieving smooth transition between the blade 105 and the circular tube 104.

(21) The circular tube 104 of the blade profile tube pre-swirl nozzle as shown in the figures is designed based on the circular tube pre-swirl nozzle, significantly decreasing the number of the blades and increasing the size of the blade height. Distinct advantages are achieved compared with the blade profile hole pre-swirl nozzle in that the blade profile hole pre-swirl nozzle can achieve the effect of increasing the blade height only by decreasing the throat width of a single passage and cannot significantly decrease the number of the blades without degrading performance. According to the blade profile tube pre-swirl nozzle of the preceding embodiment, the smaller number of the blades and larger blade height size overcome the defects of the blade type pre-swirl nozzle and modifications thereof, and therefore, the production and manufacturing difficulty can be reduced and the yield rate can be improved.

(22) Further referring to FIGS. 1-6, the airflow circulation passage before the circular tube 104 of the blade profile tube pre-swirl nozzle of the present disclosure is designed based on the blade type pre-swirl nozzle, the cross-section of the flow passage smoothly tapers to the shape of a circular tube along the blade profile, and therefore the problems of the excessive thickness near the leading edge, the flat and blunt leading edge and the like of the blade profile hole pre-swirl nozzle will not occur. The flat and blunt leading edge and large thickness of the blade profile hole pre-swirl nozzle cause severe performance degrading of the nozzle in a working condition with a slightly low Reynolds number, while the blade profile tube pre-swirl nozzle has the performance level similar to that of the blade type and working range with stable performance.

(23) FIG. 7 shows a further embodiment of the present disclosure, and the description of the same technical content is selectively omitted in this embodiment. With regard to the description of the omitted part, reference can be made to the preceding embodiment, and no redundant description will be provided in this embodiment.

(24) The differences between the embodiment shown in FIG. 7 and the preceding embodiment are: an outlet section 206 is a circular tube 204 with the diameter not changing along the axis, the circular tube 204 takes a straight line 209 as the axis, and the straight line 209 penetrates through the center of a circular cross-section 203 and is parallel to a normal vector of the circular cross-section 203.

(25) FIG. 8 shows a still further embodiment of the present disclosure, and the description of the same technical content is selectively omitted in this embodiment. With regard to the description of the omitted part, reference can be made to the preceding embodiment, and no redundant description will be provided in this embodiment. As shown in FIG. 8, the differences between this embodiment and that shown in FIGS. 1-6 are: an outlet section 306 is a circular tube 304 with the diameter not changing along the axis, and the circular tube 304 takes a projection line 310 of the straight line 309 as the axis. The projection line 310 is the projection of the straight line 309 on a revolving face on which the center of the circular cross-section 303 is located, and the revolving face is a cylindrical face with a radius defined by a vertical line from the center of the circular cross-section 303 to an axis of the blade profile tube nozzle 301 and is stretched parallel to the axial direction of blade profile tube nozzle 301.

(26) According to tests of inventors, the flow coefficient range of the same type of pre-swirl nozzles near the pressure ratio of 1.6 is listed as follows:

(27) TABLE-US-00001 Nozzle type Flow coefficient range Blade type 0.91-0.95.sup.[1]  Straight circular tube type Below 0.89.sup.[4] Flared tube type (prior art 1) 0.88-0.91.sup.[1][2] Blade profile hole type (prior art 2) 0.94.sup.[3] Blade profile tube type of the present 0.92-0.95  .sup.  disclosure

REFERENCES

(28) [1] A CFD ANALYSIS TOWARDS FLOW CHARACTERISTICS OF THREE PRE-SWIRL DESIGNS, Adrien Dulac, Master of Science Thesis, Royal Institute of Technology, Sweden [2] Investigation on Flow Characteristics and Temperature Drop of an Aerodynamic-Hole Typed Pre-Swirl Nozzle, LIU Gaowen et al., Propulsion Technology, Vol. 34, No. 3, April 2013 [3] Numerical Investigation on Flow Characteristics of a Vane Shaped Hole Preswirl Nozzle, LIU Yuxin et al., Propulsion Technology, Vol. 37, No. 2, February 2016 [4] Numerical Investigation on the Flow of Preswirl Nozzle in Gas Turbine, LIU Gaowen et al., Propulsion Technology, Vol. 34, No. 5, May 2013

(29) The present disclosure has been disclosed above in terms of the preferred embodiments which, however, are not intended to limit the present disclosure, and any person skilled in the art could make possible changes and alterations without departing from the spirit and scope of the present disclosure. Hence, any alterations, equivalent changes and modifications which are made to the above-mentioned embodiments in accordance with the technical substance of the present disclosure and without departing from the content of the technical solutions of the present disclosure, will fall within the scope of protection defined by the claims of the present disclosure.