Underground water injection turbine generator

Abstract

The utility model discloses an underground water injection turbine generator which comprises a generator body, a guide wheel, a turbine structure and a vortex hoop. The turbine structure comprises a bearing, a turbine disc and a plurality of turbine blades; the bearing is rotationally connected with a spindle of the generator body; the turbine disc is rotationally connected with a main shaft of the generator body through a bearing, the turbine blades are fixedly arranged on the outer wall of the turbine disc, and the sides, away from the turbine disc, of the turbine blades are fixedly connected with the inner wall of the vortex hoop. The guide wheel is fixedly connected with a main shaft of the generator body and located on the side, back to the generator body, of the turbine structure. The vortex hoop is fixedly arranged on the side, away from the turbine disc, of the turbine blade, so that when the underground water injection turbine generator works, the centrifugal force of the turbine blade completely acts on the vortex hoop, the turbine blade only needs to bear pressure stress instead of traditional tensile stress, the centrifugal load borne by the turbine blade is reduced, and the service life of a turbine is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of downhole generators, and in particular to downhole water injection turbine generators. Background Art

[0002] In the current oil and gas production field, the traditional stratified water injection technology requires continuous power supply to the downhole equipment during water injection and production operations. The equipment currently used to power downhole instruments usually uses energy storage batteries, wired cables or turbine generators.

[0003] Among them, energy storage batteries generally use lithium batteries, whose volume is proportional to capacity. However, the underground space of water injection wells is limited and cannot accommodate a large number of lithium batteries, resulting in insufficient power supply. This requires regular replacement of energy storage lithium batteries, and there is a risk of leakage when lithium batteries work in deep wells with high temperature and high pressure, which not only increases the cost of mining, but also is not the best solution from the perspective of environmental protection. Although wired cables can supply power over long distances, as the use time increases, short circuits, overloads, leakage and other faults will occur, causing direct economic losses to the oil field. In addition, there is generally no power supply around water injection wells, and poles need to be erected for long-distance power transmission, which also increases the cost of oil field mining. In the existing downhole water injection turbine generator technology, the "A Constant Pressure Turbine Generator" with patent announcement number CN214799178U includes a stator, a rotor, a magnetic flange, and a coil group. The rotor drives the magnetic flange to rotate. The magnetic flange and the coil group are arranged opposite to each other, and there is a certain gap between the two. The gap is adjusted by a gap adjustment mechanism. The output voltage is adjusted by adjusting the gap to maintain the voltage at a standard value. It adapts to a wider range of mud displacement and pressure, avoiding the trouble of replacing different stators and rotors.

[0004] When the existing downhole water injection turbine generator is working, its turbine blades will be subjected to tensile stress under the action of centrifugal force. The centrifugal load on the turbine blades is relatively high, which affects the life of the turbine. Therefore, it is necessary to consider reducing or eliminating the centrifugal load. However, the above-mentioned prior art has not studied this problem, and the service life of the turbine is relatively low. Utility Model Content

[0005] The present application provides a downhole water injection turbine generator, which is used to solve the problems of high centrifugal load on turbine blades and low turbine service life in the existing downhole water injection turbine generator technology.

[0006] On the one hand, the present application provides a downhole water injection turbine generator, comprising: a generator body, a guide wheel, a turbine structure and a vortex hoop.

[0007] The turbine structure comprises: a bearing, a turbine disk and a plurality of turbine blades.

[0008] The bearing is rotatably connected to the main shaft of the generator body.

[0009] The turbine disk is rotationally connected to the main shaft of the generator body through the bearing, the turbine blades are fixedly arranged on the outer wall of the turbine disk, and the side of the turbine blades away from the turbine disk is fixedly connected to the inner wall of the vortex hoop.

[0010] The guide wheel is fixedly connected to the main shaft of the generator body, and the guide wheel is located on a side of the turbine structure facing away from the generator body.

[0011] In a possible implementation, the inner and outer diameters of the turbine structure are the same as the inner and outer diameters of the guide wheel.

[0012] In a possible implementation, the sum of the blade height of the turbine blade and the diameter of the turbine disk is smaller than the inner diameter of the downhole flow channel.

[0013] In a possible implementation, the turbine blade is a spiral structure.

[0014] In a possible implementation, the installation angle of the turbine blade is equal to the angle between the circumferential velocity of the turbine blade and the axial velocity component of the fluid in the turbine.

[0015] In a possible implementation, the guide wheel is provided with a plurality of guide holes, and the directions of the guide holes are parallel to the direction of the main axis of the generator body.

[0016] In a possible implementation manner, the number of the guide holes is the same as the number of the turbine blades.

[0017] The downhole water injection turbine generator in this application has the following advantages:

[0018] By fixing a vortex hoop on the side of the turbine blade away from the turbine disk, when the underground water injection turbine generator is working, the centrifugal force of the turbine blade all acts on the vortex hoop, and the turbine blade only needs to withstand compressive stress instead of traditional tensile stress, thereby reducing the centrifugal load on the turbine blade and improving the service life of the turbine.

[0019] The inner and outer diameters of the proposed turbine structure are the same as the inner and outer diameters of the guide wheel, which improves the matching degree between the turbine structure and the guide wheel, reduces flow loss, and improves energy conversion efficiency.

[0020] The proposed guide wheel is provided with a plurality of guide holes, the direction of the guide holes is parallel to the direction of the main axis of the generator body, and the fluid is guided through the guide holes, thereby improving the flow guidance effect.

[0021] The number of the proposed guide holes is the same as that of the turbine blades, thereby improving the matching degree between the guide holes and the turbine blades and improving the flow guide stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the structure of a downhole water injection turbine generator provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of the structure of a downhole water injection turbine generator provided in an embodiment of the present application when no vortex collar is provided;

[0025] Figure 3 A schematic diagram of the three-dimensional structure of the turbine structure and the vortex hoop provided in an embodiment of the present application;

[0026] Figure 4 A schematic cross-sectional structure diagram of a turbine structure and a vortex hoop provided in an embodiment of the present application;

[0027] Figure 5 A static pressure cloud diagram of a turbine blade without a vortex collar provided in an embodiment of the present application;

[0028] Figure 6 A static pressure cloud diagram of a turbine blade with a vortex hoop provided in an embodiment of the present application;

[0029] Figure 7 A diagram of the turbine rotation rate when there is no vortex collar provided in an embodiment of the present application;

[0030] Figure 8 A diagram of the turbine rotation rate when a vortex hoop is provided for an embodiment of the present application.

[0031] Description of reference numerals:

[0032] 1-generator body, 2-guide wheel, 3-turbine structure, 4-vortex hoop, 11-main shaft, 21-guide hole, 31-bearing, 32-turbine disk, 33-turbine blade. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] like Figures 1 to 4As shown, an embodiment of the present application provides a downhole water injection turbine generator, comprising: a generator body 1, a guide wheel 2, a turbine structure 3 and a vortex hoop 4.

[0035] The turbine structure 3 includes a bearing 31 , a turbine disk 32 and a plurality of turbine blades 33 .

[0036] The bearing 31 is rotatably connected to the main shaft 11 of the generator body 1 .

[0037] The turbine disk 32 is rotationally connected to the main shaft 11 of the generator body 1 through the bearing 31, and the turbine blades 33 are fixedly arranged on the outer wall of the turbine disk 32. The side of the turbine blades 33 away from the turbine disk 32 is fixedly connected to the inner wall of the vortex hoop 4.

[0038] The guide wheel 2 is fixedly connected to the main shaft 11 of the generator body 1 , and the guide wheel 2 is located on a side of the turbine structure 3 facing away from the generator body 1 .

[0039] Specifically, in this embodiment, the working environment of the downhole water injection turbine generator is as follows: the flow channel diameter D0 = 20 mm, the liquid flow rate Q through the flow channel = 50 m 3 / d, the liquid density is approximately the density of clean water ρ = 1000kg / m 3 , ambient temperature 150℃, ambient pressure 80MPa.

[0040] Exemplarily, the inner and outer diameters of the turbine structure 3 are the same as the inner and outer diameters of the guide wheel 2 .

[0041] Specifically, in this embodiment, the outer diameter of the guide wheel 2 is 18 mm, and the inner diameter is 10 mm, then the outer diameter D1 of the turbine structure 3 is 18 mm, and the inner diameter D2 (ie, the diameter of the turbine disk 32) is 10 mm.

[0042] Exemplarily, the sum of the blade height of the turbine blade 33 and the diameter of the turbine disk 32 is smaller than the inner diameter of the downhole flow channel.

[0043] Specifically, the sum of the blade height b of the turbine blade 33 and the inner diameter of the turbine structure 3 is set to be smaller than the diameter of the downhole flow channel, so that the turbine blade 33 can rotate in the downhole flow channel. In this embodiment, the blade height of the turbine blade 33 is set to 4 mm.

[0044] In this embodiment, the rated speed N of the generator body 1 is set to 3000 r / min. The thickness of the vortex hoop 4 is set to 2 mm.

[0045] Exemplarily, the turbine blade 33 is a spiral structure.

[0046] Specifically, in this embodiment, the turbine structure 3 adopts an axial flow type, so the liquid flows axially in the turbine structure 3, and the calculated diameter of the turbine structure 3 adopts the average diameter D of the outer diameter D1 and the inner diameter D2 of the turbine structure 3, as shown in the following formula:

[0047]

[0048] Exemplarily, the installation angle of the turbine blade 33 is equal to the angle between the circumferential velocity of the turbine blade 33 and the axial velocity component of the fluid in the turbine.

[0049] Specifically, in this embodiment, the axial velocity component C of the fluid in the turbine is Z The calculation formula is as follows:

[0050]

[0051] In the formula, F S is the cross-sectional area of ​​the stator outlet flow channel perpendicular to the axial direction, mm 2 , Q is the actual flow rate through the turbine flow channel, m 3 / s, after conversion, Q = 5.787 × 10 -4 m 3 / s. And there are Where, b is the leaf height, mm; The displacement coefficient is generally taken as 0.9 to consider the influence of blade thickness. After substituting the data, the axial velocity component C of the fluid in the turbine is obtained. Z As shown below:

[0052]

[0053] In this embodiment, the circumferential speed u of the turbine blade 33 is expressed as follows:

[0054]

[0055] The installation angle β of the turbine blade 33 m = ... Z The angle is as follows:

[0056]

[0057] Since the axial velocity component C of the fluid in the turbine in this embodiment Z The displacement coefficient has been taken into account, so the helix angle β of the turbine blade 33 can be calculated according to the axial velocity component C of the fluid in the turbine. Z, circumferential speed u, torque M generated by liquid impacting turbine blades and output power P are obtained jointly. Assuming that the spiral guide wheel and turbine structure 3 required for the initial design of the downhole water injection turbine generator are completely symmetrical structures, the torque M generated by liquid impacting turbine blades 33 can be approximately obtained as shown in the following formula:

[0058]

[0059] The output power P is shown as follows:

[0060]

[0061] Substituting the data into the equation, we obtain tanβ=0.969, which means the helix angle β is 44.09°.

[0062] Specifically, in this embodiment, the axial height h of the turbine blade 33 is expressed as follows:

[0063]

[0064] Where θ is the blade rotation angle, also known as the plane wrap angle of each section of the blade. The initial value of θ is generally determined to be π / 2. Substituting the data into the axial height h, the following formula is obtained:

[0065]

[0066] The chord length s of the turbine blade 33 is expressed as follows:

[0067]

[0068] The relative pitch t of the turbine blades 33 is expressed as follows:

[0069] t=0.85s=9.452。

[0070] The number Z of the turbine blades 33 is expressed as follows:

[0071]

[0072] The various parameters of the turbine structure 3 in this embodiment are only used to assist in explaining the structure of the turbine structure 3, rather than to limit the turbine structure 3. In other possible embodiments, the various parameters of the turbine structure 3 can be calculated and adjusted according to actual conditions.

[0073] Exemplarily, the guide wheel 2 is provided with a plurality of guide holes 21 , and the directions of the guide holes 21 are parallel to the direction of the main shaft 11 of the generator body 1 .

[0074] Exemplarily, the number of the guide holes 21 is the same as the number of the turbine blades 33 .

[0075] In a possible embodiment, the combined structure consisting of the turbine structure 3 and the vortex hoop 4 in the present application is simulated with the turbine structure 3 to analyze and compare the pressure on the turbine blades 33, the well fluid flow rate, and the rotation speed of the turbine blades 33 with and without the vortex hoop 4.

[0076] like Figures 5 and 6 As shown, when there is no vortex hoop 4, the turbine blade 33 is subjected to greater pressure at the inlet, which causes the static pressure difference inside the turbine to increase, which is not conducive to stable operation; when there is a vortex hoop 4, the static pressure area of ​​the turbine blade 33 is reduced, which ensures the working efficiency of the turbine while improving the service life of the turbine.

[0077] like Figures 7 and 8 As shown, compared with the turbine blades 33 without the vortex hoop 4, the turbine blades 33 with the vortex hoop 4 can better convert the water efficiency into mechanical energy, thereby obtaining a higher rotation speed and allowing the generator to achieve a higher power.

[0078] The embodiment of the present application fixes a vortex hoop on the side of the turbine blade away from the turbine disk, so that when the downhole water injection turbine generator is working, the centrifugal force of the turbine blade acts entirely on the vortex hoop, and the turbine blade only needs to withstand compressive stress instead of traditional tensile stress, thereby reducing the centrifugal load on the turbine blade and improving the service life of the turbine.

[0079] The inner and outer diameters of the proposed turbine structure are the same as the inner and outer diameters of the guide wheel, which improves the matching degree between the turbine structure and the guide wheel, reduces flow loss, and improves energy conversion efficiency.

[0080] The proposed guide wheel is provided with a plurality of guide holes, the direction of the guide holes is parallel to the direction of the main axis of the generator body, and the fluid is guided through the guide holes, thereby improving the flow guidance effect.

[0081] The number of the proposed guide holes is the same as that of the turbine blades, thereby improving the matching degree between the guide holes and the turbine blades and improving the flow guide stability.

[0082] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0083] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. Downhole water injection turbine generator, characterized in that: include: Generator body, guide wheel, turbine structure and vortex hoop; The turbine structure includes: a bearing, a turbine disk and a plurality of turbine blades; The bearing is rotatably connected to the main shaft of the generator body; The turbine disc is rotatably connected to the main shaft of the generator body through the bearing, the turbine blade is fixedly arranged on the outer wall of the turbine disc, and the side of the turbine blade away from the turbine disc is fixedly connected to the inner wall of the vortex hoop; The guide wheel is fixedly connected to the main shaft of the generator body, and the guide wheel is located on a side of the turbine structure facing away from the generator body.

2. The downhole water injection turbine generator according to claim 1, characterized in that: The inner and outer diameters of the turbine structure are the same as the inner and outer diameters of the guide wheel.

3. The downhole water injection turbine generator according to claim 1, characterized in that: The sum of the blade height of the turbine blade and the diameter of the turbine disk is smaller than the inner diameter of the downhole flow channel.

4. The downhole water injection turbine generator according to claim 1, characterized in that: The turbine blade is a spiral structure.

5. The downhole water injection turbine generator according to claim 1, characterized in that: The installation angle of the turbine blade is equal to the angle between the circumferential speed of the turbine blade and the axial speed component of the fluid in the turbine.

6. The downhole water injection turbine generator according to claim 1, characterized in that: The guide wheel is provided with a plurality of guide holes, and the directions of the guide holes are parallel to the direction of the main axis of the generator body.

7. The downhole water injection turbine generator according to claim 6, characterized in that: The number of the guide holes is the same as the number of the turbine blades.

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