Water distribution ring pipe with adjustable pitch diameter and impulse turbine system

Abstract

The invention relates to the technical field of fluid machinery, in particular to a water distribution ring pipe with an adjustable pitch diameter and an impulse turbine system. The water distribution ring pipe comprises a water distribution main pipe which is of an annular structure and is arranged on the outer side of the rotating wheel; and the water distribution branch pipes are movably connected with the water distribution main pipe, the water distribution branch pipes are arranged towards the rotating wheels, and the spraying directions of the water distribution branch pipes are adjusted to be matched with the rotating wheels with different pitch circle diameters through the movable connection of the water distribution branch pipes and the water distribution main pipe. According to the water distribution ring pipe with the adjustable pitch circle diameter and the impulse turbine system, the spraying direction of the water distribution branch pipes can be matched with rotating wheels with different pitch circle diameters by adjusting the positions of the water distribution branch pipes; the whole set of water distribution ring pipe system does not need to be additionally designed and machined, other water distribution ring pipe assemblies do not need to be disassembled and replaced, the rotating wheels with different pitch circle diameters can be subjected to model tests only through one water distribution ring pipe, the machining design process is simplified, time and labor are saved, installation is convenient, working efficiency is improved, and economical efficiency is good.

Description

Technical Field

[0001] The invention relates to the technical field of fluid machinery, and in particular to a water distribution ring pipe with adjustable pitch circle diameter and an impulse turbine system. Background Art

[0002] During the research and development of the impulse turbine, the optimization analysis of its hydraulic performance mainly relies on CFD calculations and model tests, and model tests must be verified during design finalization and bidding. According to IEC international standards and GB national standards, unlike the requirement that the model runner diameter D of the reaction turbine is not less than 350mm, the requirement for the model unit in the impulse turbine model test is that the inner width of the model runner bucket is not less than 80mm, and there are no excessive requirements for the runner pitch circle diameter. Therefore, for the model unit of the impulse turbine, the inner width of the bucket is generally fixed, and in order to obtain a unit with suitable performance, the runner pitch circle diameter is often not fixed at the beginning during the design and optimization stage, but will go through an optimization process.

[0003] In a multi-nozzle impulse turbine and its model unit, the center line of each injection mechanism is tangent to the pitch circle of the runner. Therefore, when the impulse turbine model test with different pitch circle diameters is carried out on the same test bench, the runners of each pitch circle diameter need to have their own matching water distribution ring pipes. Therefore, it is often necessary to process multiple sets of water distribution ring pipes during the model test. In the model unit of the impulse turbine, the water distribution ring pipe has the largest size and is the most difficult to install, which consumes more energy and processing materials, and is time-consuming and labor-intensive. At the same time, due to the unique structure of the impulse turbine, the hydraulic efficiency of its runner itself changes little with the structure of the injection mechanism and the water distribution ring pipe, and the hydraulic loss of the impulse turbine water distribution ring pipe section is also small. Only a small range of changes in the matching angle between the outlet of the water distribution ring pipe branch pipe and the inlet of the injection mechanism will not have a big impact on the overall hydraulic efficiency of the water distribution ring pipe.

[0004] In summary, during the model test stage of the impulse turbine, when conducting model tests on impulse turbines with different runner pitch diameters, it is necessary to design and process multiple sets of matching water distribution ring pipes, which has the defects of time-consuming and labor-intensive processing, difficult installation, low work efficiency, and poor economy. Summary of the invention

[0005] The present invention provides a water distribution ring pipe with adjustable pitch circle diameter and an impulse turbine system, which are used to solve the problem in the background technology that during the model test stage of the impulse turbine, when the model test is carried out on the impulse turbines with different runner pitch circle diameters, a plurality of sets of matching water distribution ring pipes need to be designed and processed accordingly, which has the defects of time-consuming and labor-intensive processing, difficult installation, low working efficiency and poor economy.

[0006] The present invention provides a water distribution ring pipe with adjustable pitch circle diameter, comprising: The water distribution main is annular in structure and is located outside the runner; A water distribution branch pipe is movably connected to the water distribution main pipe, the water distribution branch pipe is arranged toward the impeller, and through the movably connected to the water distribution main pipe, the spraying direction of the water distribution branch pipe can be adjusted to match the impeller with different pitch circle diameters.

[0007] The water distribution ring pipe with adjustable pitch circle diameter provided by the present invention also includes: a flexible connector, through which the water distribution branch pipe is movably connected to the water distribution main pipe to adjust the injection direction of the water distribution branch pipe to match the pitch circle diameters of different wheels.

[0008] According to the water distribution ring pipe with adjustable pitch circle diameter provided by the present invention, a plurality of flexible connectors are provided, and the water distribution branch pipe includes a hard nozzle and at least one hard connecting pipe, the hard connecting pipe is connected to the water distribution main pipe through a flexible connector, and the hard nozzle and the hard connecting pipe are connected through the flexible connector.

[0009] According to the water distribution ring pipe with adjustable pitch circle diameter provided by the present invention, a plurality of the hard connecting pipes are provided, and two adjacent hard connecting pipes are connected by the soft connecting piece.

[0010] According to the water distribution ring pipe with adjustable pitch circle diameter provided by the present invention, the hard connecting pipe includes: a first connecting pipe and a second connecting pipe located downstream of the water distribution main pipe, the first connecting pipe is connected to the three-way pipe of the water distribution main pipe, the soft connecting piece is arranged between the first connecting pipe and the three-way pipe, and the soft connecting piece is arranged between the second connecting pipe and the downstream of the water distribution main pipe.

[0011] According to the water distribution ring pipe with adjustable pitch circle diameter provided by the present invention, the adjustment angle of the flexible connector has a value range of -5° to 5°.

[0012] According to the water distribution ring pipe with adjustable pitch circle diameter provided by the present invention, the water distribution branch pipe is a soft nozzle, and the angle between the soft nozzle and the water distribution main pipe is adjusted to make the spraying direction of the soft nozzle match the pitch circle diameters of different impellers.

[0013] According to the water distribution ring pipe with adjustable pitch circle diameter provided by the present invention, a plurality of water distribution branch pipes are provided, and when a model test is performed on impulse turbines with different runner pitch circle diameters, the adjustment angle of each water distribution branch pipe is the same.

[0014] The present invention also provides an impulse turbine system, comprising: the water distribution ring pipe with adjustable pitch circle diameter provided by the present invention.

[0015] The impulse turbine system provided according to the present invention further comprises: an injection mechanism, wherein the injection mechanism is arranged downstream of the water distribution branch pipe.

[0016] The present invention provides a water distribution ring pipe with adjustable pitch circle diameter, which includes: a water distribution main pipe and a water distribution branch pipe; the water distribution main pipe is annular and arranged on the outside of the runner; the water distribution branch pipe is movably connected to the water distribution main pipe, the water distribution branch pipe is arranged toward the runner, and the water distribution branch pipe is movably connected to the water distribution main pipe to adjust the injection direction of the water distribution branch pipe to match the runners with different pitch circle diameters. The present invention provides a water distribution ring pipe with adjustable pitch circle diameter, which can match the injection direction of the runners with different pitch circle diameters by adjusting the angle of the water distribution branch pipe; in the model test stage of the impulse turbine, when the model test is performed on the impulse turbine with different runner pitch circle diameters, it is necessary to frequently replace the runners with different pitch circle diameters for testing. The present invention does not require additional processing and design of the water distribution ring pipe, nor does it require disassembly and replacement of other water distribution ring pipes. Only one water distribution ring pipe with adjustable pitch circle diameter can meet the test of runners with different pitch circle diameters, simplifying the processing and design process, saving time and labor, facilitating installation, improving work efficiency, and having good economy.

[0017] Furthermore, the present invention also provides an impulse turbine system, which includes the water distribution ring pipe with adjustable pitch circle diameter of the present invention, and therefore has the same advantages as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic structural diagram of a water distribution ring pipe with adjustable pitch circle diameter provided in one embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure of a water distribution branch pipe provided in one embodiment of the present invention.

[0021] Figure 3 It is a schematic diagram of the structure of a water distribution branch pipe provided in one embodiment of the present invention.

[0022] Figure 4 It is a schematic diagram of the internal structure of the injection mechanism provided in one embodiment of the present invention.

[0023] Figure 5 It is a partial structural schematic diagram of a nozzle assembly and a spray needle assembly provided in one embodiment of the present invention.

[0024] Figure 6 It is a comparison chart of the spray needle tip sizes and their corresponding efficiencies provided by the present invention.

[0025] Reference numerals: 100: water distribution main pipe; 200: water distribution branch pipe; 201: hard nozzle; 202: hard connecting pipe; 300: soft connecting piece; 400: runner; 500: straight pipe section; 600: spray needle assembly; 601: support plate; 602: spray needle body; 603: spray needle tip; 604: connecting body; 700: nozzle assembly; 701: nozzle body; 702: expansion section; 703: sealing ring; L: length of spray needle tip; D: diameter of nozzle assembly; C: ratio of the length of spray needle tip to the diameter of nozzle assembly. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0027] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0028] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0029] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0030] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0031] Combine the following Figure 1-Figure 3 ( Figure 1 The middle dotted line indicates that the water distribution branch pipe 200 rotates to different angles and the direction of water flow) describes a water distribution ring pipe with adjustable pitch circle diameter of the present invention. The water distribution ring pipe with adjustable pitch circle diameter includes: a water distribution main pipe 100 and a water distribution branch pipe 200.

[0032] Among them, the water distribution main pipe 100 is annular in structure and is arranged on the outside of the impeller 400; the water distribution branch pipe 200 is movably connected to the water distribution main pipe 100, and the water distribution branch pipe 200 is arranged toward the impeller 400, and through the movably connected with the water distribution main pipe 100, the injection direction of the water distribution branch pipe 200 can be adjusted to match the impeller 400 with different pitch circle diameters.

[0033] Specifically, the water distribution main pipe 100 is used to supply water to the water distribution branch pipes 200. Water enters the upstream of the water distribution main pipe 100 and supplies water to each downstream water distribution branch pipe 200. The water distribution main pipe 100 is annular in structure, which surrounds the outer side of the impeller 400, and sprays water to the impeller 400 through the water distribution branch pipes 200, thereby driving the impeller 400 to rotate and perform work.

[0034] In the model test stage of the impulse turbine, when the model test is conducted on the impulse turbine with different pitch circle diameters of the runner 400, it is necessary to frequently replace the runner 400 with different pitch circle diameters for testing. During the test, it is necessary to ensure that the spray direction of the water distribution branch pipe 200 is toward the runner 400. Therefore, in the embodiment of the present invention, the water distribution branch pipe 200 and the water distribution main pipe 100 are changed from the traditional hard connection mode to the soft connection mode, that is, the two are movably connected, so that the water distribution branch pipe 200 can be bent and deformed within a certain range on the plane, and each injection mechanism connected thereto can also change its position accordingly, thereby adjusting the direction of the jet of the water distribution branch pipe 200 so that its injection direction is always tangent to the pitch circle where the runner 400 of the impulse turbine is located in the simulation test stage. Specifically, the angle of adjustment of the water distribution branch pipe 200 should meet the requirement that the position of the center line of the outlet of the downstream injection mechanism is tangent to the pitch circle where the runner 400 is located in the simulation test stage.

[0035] Since the spray direction of the water distribution branch pipe 200 in the embodiment of the present invention is adjusted according to the runner 400 of different pitch circle diameters, in order to ensure the hydraulic performance, the hydraulic performance of the water distribution branch pipe 200 with different spray angles is tested. In the specific test process, CFD software is used to perform three-dimensional flow calculations, analyze the flow conditions inside the water distribution ring pipe, analyze the influence of the rotation angle of the water distribution branch pipe 200 on the flow field inside the water distribution ring pipe, and analyze the influence on the hydraulic performance of the water distribution ring pipe.

[0036] Through the numerical calculation results, it can be found that the efficiency of the water distribution ring pipe changes little when the water distribution branch pipe 200 rotates to the maximum angle, and the impact on the overall hydraulic performance of the water distribution ring pipe is small. The water distribution ring pipe can still maintain a high hydraulic performance under the premise of being able to adapt to the runner 400 of different pitch circle diameters. Therefore, the water distribution ring pipe is reliable and can save time and cost for model tests of different pitch circle diameters and improve economic efficiency. The specific test data are shown in Table 1 below:

[0037] Table 1: Changes in water distribution ring performance

[0038] The present invention provides a water distribution ring pipe with adjustable pitch circle diameter, which includes: a water distribution main pipe 100 and a water distribution branch pipe 200; the water distribution main pipe 100 is annular in structure and is arranged on the outside of a runner 400; the water distribution branch pipe 200 is movably connected to the water distribution main pipe 100, the water distribution branch pipe 200 is arranged toward the runner 400, and is movably connected to the water distribution main pipe 100 to adjust the injection direction of the water distribution branch pipe 200 to match the runner 400 with different pitch circle diameters. The present invention provides a water distribution ring pipe with adjustable pitch circle diameter, which can adjust the angle of the water distribution branch pipe 200 so that its injection direction matches the runner 400 with different pitch circle diameters; in the model test stage of the impulse turbine, when the impulse turbine with different pitch circle diameters of the runner 400 is tested, it is necessary to frequently replace the runner 400 with different pitch circle diameters for testing. The present invention does not require additional processing and design of the water distribution ring pipe, nor does it require disassembly and replacement of other water distribution ring pipes. Only one water distribution ring pipe with adjustable pitch circle diameter can meet the test of the runner 400 with different pitch circle diameters, thereby simplifying the processing and design process, saving time and labor, facilitating installation, improving work efficiency, and having good economy.

[0039] In one embodiment of the present invention, the water distribution ring pipe with adjustable pitch diameter further includes: a flexible connector 300, through which the water distribution branch pipe 200 is movably connected to the water distribution main pipe 100, so as to adjust the spray direction of the water distribution branch pipe 200 to match the runner 400 with different pitch diameters. In this embodiment, by arranging the flexible connector 300 between the water distribution branch pipe 200 and the water distribution main pipe 100, the angle of the water distribution branch pipe 200 in the water distribution main pipe 100 is adjustable to achieve a flexible connection. When the spray angle of the water distribution branch pipe 200 needs to be adjusted, the flexible connector 300 is forced to change its shape by applying external force, thereby changing the angle of the water distribution branch pipe 200, so that its spray direction matches the runner 400 with different pitch diameters. Specifically, the flexible connector 300 may be a movable joint or a movable hose. If the injection pressure is relatively high, after the angle of the water distribution branch pipe 200 is adjusted, a positioning member / fixing member may be used to fix the angle of the water distribution branch pipe 200 to prevent the angle from changing under the injection pressure.

[0040] In one embodiment of the present invention, multiple flexible connectors 300 are provided, and the water distribution branch pipe 200 includes a hard nozzle 201 and at least one hard connection pipe 202. The hard connection pipe 202 is connected to the water distribution main pipe 100 through the flexible connector 300, and the hard nozzle 201 and the hard connection pipe 202 are connected through the flexible connector 300. In this embodiment, the water distribution branch pipe 200 is composed of a hard nozzle 201 and a hard connection pipe 202. The hard connection pipe 202 is connected between the hard nozzle 201 and the water distribution main pipe 100. The hard nozzle 201 and the hard connection pipe 202 are both made of hard materials and cannot be bent. The angle of the hard nozzle 201 is adjusted only by the flexible connector 300. By providing multiple flexible connectors 300, the range of angle adjustment of the hard nozzle 201 is increased, and it can be applied to runners 400 with various pitch circle sizes.

[0041] In one embodiment of the present invention, multiple rigid connection tubes 202 are provided, and two adjacent rigid connection tubes 202 are connected by a soft connection member 300. In this embodiment, in order to further improve the angle adjustment range of the rigid nozzle 201, multiple rigid connection tubes 202 can be connected in sequence, and two adjacent rigid connection tubes 202 are connected by a soft connection member 300, so that the angles of each rigid connection tube 202 are adjustable. Preferably, two rigid connection tubes 202 are arranged, and a soft connection member 300 is connected between the two rigid connection tubes 202.

[0042] In one embodiment of the present invention, the hard connecting pipe 202 includes: a first connecting pipe and a second connecting pipe located downstream of the water distribution main pipe 100, the first connecting pipe is connected to the three-way pipe of the water distribution main pipe 100, the soft connecting member 300 is arranged between the first connecting pipe and the three-way pipe, and the soft connecting member 300 is arranged between the second connecting pipe and the downstream of the water distribution main pipe 100. In this embodiment, according to the different positions of the hard connecting pipe 202 in the water distribution main pipe 100, it is divided into a first connecting pipe connected to the upstream or middle section of the water distribution main pipe 100 (i.e., Figure 3 The structure shown in FIG. 1 ) and a second connecting pipe (i.e., as shown in FIG. 1 ) connected to the downstream of the water distribution main pipe 100 Figure 2 In order to ensure that the water distribution main pipe 100 supplies water to the downstream, the first connecting pipe is connected to the three-way pipe of the water distribution main pipe 100. One way of the three-way pipe is connected to the upstream of the water distribution main pipe 100, one way is connected to the downstream of the water distribution main pipe 100, and one way is connected to the first connecting pipe, which does not affect the water supply of the water distribution main pipe 100, and can ensure the water spraying and corresponding angle adjustment of the water distribution branch pipe 200.

[0043] In one embodiment of the present invention, the adjustment angle of the flexible connector 300 ranges from -5° to 5°. It should be understood that the angle adjustment range of each flexible connector 300 is between -5° and 5°. If multiple flexible connectors 300 are provided, the rotation angle of the water distribution branch pipe 200 can be increased. In addition, each flexible connector 300 can rotate within the above angle range and still maintain a high hydraulic performance.

[0044] In one embodiment of the present invention, the water distribution branch pipe 200 is a soft nozzle. By adjusting the angle between the soft nozzle and the water distribution main pipe 100, the spray direction of the soft nozzle matches the runner 400 with different pitch circle diameters (not shown in this embodiment). Different from the form of using a soft connector 300 to connect the hard pipeline in the above embodiment, the water distribution branch pipe 200 in this embodiment is made of a soft material to make a soft nozzle. It is necessary to ensure that the angle does not change under the action of the spray water pressure. By applying an external force, the angle of the soft nozzle is adjusted to match the runner 400 with different pitch circle diameters. In this embodiment, the function of the soft nozzle is similar to the function of the structure composed of the soft connector 300, the hard connecting pipe 202 and the hard nozzle 201 in the above embodiment, and both have the function of adjusting the spray angle.

[0045] In one embodiment of the present invention, a plurality of water distribution branch pipes 200 are provided, and when a model test is performed on an impulse turbine with different pitch circle diameters of the impeller 400, the adjustment angle of each water distribution branch pipe 200 is the same. The water distribution ring pipe in the implementation of the present invention is suitable for a multi-nozzle impulse turbine system, that is, it is necessary to configure a plurality of water distribution branch pipes 200 accordingly. In order to ensure that each water distribution branch pipe 200 matches the impeller 400, the adjustment angle of each water distribution branch pipe 200 is the same. For example: the adjustment angle of each water distribution branch pipe 200 is 5°, ensuring that each water distribution branch pipe 200 is tangent to the pitch circle where the impeller 400 is located during the simulation test stage. In particular, due to the influence of factors such as the shape and layout of the water distribution main pipe 100, the rotation angle of the water distribution branch pipe 200 may also be different, and it is sufficient to ensure that the water distribution branch pipe 200 is tangent to the pitch circle where the impeller 400 is located during the simulation test stage, which will not be repeated here. Figure 1 As shown, six water distribution branch pipes 200 are sequentially arranged in the embodiment of the present invention; of course, according to actual conditions, four, five or other numbers of water distribution branch pipes 200 may also be arranged to meet the standard of turbine use.

[0046] The present invention also provides an impulse turbine system, which comprises: a water distribution ring pipe with adjustable pitch circle diameter in the above embodiment of the present invention.

[0047] The present invention provides an impulse turbine system, which includes the water distribution ring pipe with adjustable pitch circle diameter in the above embodiment of the present invention, and therefore has the same advantages as above.

[0048] In one embodiment of the present invention, the impulse turbine system further includes: an injection mechanism, which is disposed downstream of the water distribution branch pipe 200 .

[0049] Combine the following Figure 4-Figure 6 The present invention describes an injection mechanism, which includes a straight pipe section 500 , a spray needle assembly 600 and a nozzle assembly 700 .

[0050] The straight pipe section 500 is a hollow structure, and one end of the straight pipe section 500 has an opening for installing the nozzle assembly 700; the needle assembly 600 includes a support plate 601, a needle body 602 and a needle tip 603, one end of the support plate 601 is fixed on the inner wall of the straight pipe section 500, one end of the needle body 602 is movably connected to the other end of the support plate 601, and the needle tip 603 is detachably arranged at the other end of the needle body 602; the nozzle assembly 700 is arranged at the opening of the straight pipe section 500, and the needle body 602 and the needle tip 603 can move in a direction close to or away from the nozzle assembly 700. The ratio C of the length L of the needle tip to the diameter D of the nozzle assembly (that is, the inner diameter of the nozzle body 701 in the following embodiment) is not greater than 0.2, that is, L / D≤0.2 or C≤0.2.

[0051] Specifically, the hollow structure of the straight pipe section 500 allows liquid to pass through, and water is supplied to the straight pipe section 500 through the water distribution ring pipe. The support plate 601 provides support and positioning for installing the needle body 602 inside the hollow structure of the straight pipe section 500.

[0052] The needle body 602 is movably connected to the support plate 601, and can move under the drive of the driving mechanism, driving the needle tip 603 to move synchronously, and the flow rate is adjusted by the movement of the needle body 602 and the needle tip 603. The nozzle assembly 700 is located at the opening of the straight pipe section 500, and the liquid is sprayed at the position of the nozzle assembly 700 and sprayed toward the rotating wheel. When the needle body is close to the nozzle assembly 700, its spray flow rate decreases; when the needle body is away from the nozzle assembly 700, its spray flow rate increases.

[0053] The present invention uses CFD software to perform three-dimensional flow calculations, analyzes the flow conditions in the free jet region, analyzes the effects of the shedding of different-sized needle tips 603 on the flow field in the free jet region, and the effects on the hydraulic performance of the nozzle. Figure 6As shown in the figure (Sn represents the opening of the nozzle), through the numerical calculation results, it can be found that when the nozzle tip 603 falls off, as the flow rate increases, the nozzle efficiency of the present invention decreases very little compared with the complete nozzle tip 603, and is within an acceptable range. According to the experimental results, when the ratio of the length of the nozzle tip 603 to the inner diameter of the nozzle body 701 in the nozzle assembly 700 is not greater than 0.2, even if the nozzle tip 603 falls off, it has little effect on the quality of the jet, but when the ratio of the length of the nozzle tip 603 to the inner diameter of the nozzle body 701 in the nozzle assembly 700 is greater than 0.2, the falling of the nozzle tip 603 has a greater impact on the quality of the jet. The present invention provides an injection mechanism suitable for the needle structure of an impulse turbine under high water head. By optimizing the geometric dimensions of the needle tip 603, CFD software is used to perform three-dimensional flow calculations on nozzle flow channels with different geometric parameters, and the hydraulic efficiency is calculated and evaluated with flow loss as the main criterion, thereby providing the needle size with the best efficiency.

[0054] On the one hand, the present invention limits the ratio of the length of the needle tip 603 to the diameter of the nozzle assembly 700, so that even if the needle tip 603 falls off, the hydraulic performance is less affected, which solves the problem of the needle tip 603 falling off due to the impact of mud and sand particles in the injection mechanism, resulting in a decrease in hydraulic performance, and can improve the economic benefits of the operation of the turbine unit; on the other hand, in the case of severe wear of the needle tip 603, since the needle tip 603 is detachably mounted on the needle body 602, the needle tip 603 can be easily disassembled and replaced, thereby ensuring the performance of the needle assembly 600.

[0055] The present invention provides an injection mechanism, which includes: a straight pipe section 500, a spray needle assembly 600 and a nozzle assembly 700; the straight pipe section 500 is a hollow structure, and one end of which has an opening; the spray needle assembly 600 includes: a support plate 601, a spray needle body 602 and a spray needle tip 603, one end of the support plate 601 is fixed to the inner wall of the straight pipe section 500, one end of the spray needle body 602 is movably connected to the other end of the support plate 601, and the spray needle tip 603 is detachably arranged at the other end of the spray needle body 602; the nozzle assembly 700 is arranged at the opening of the straight pipe section 500, and the spray needle body 602 and the spray needle tip 603 can move in a direction close to or away from the nozzle assembly 700; the ratio of the length of the spray needle tip 603 to the diameter of the nozzle assembly 700 is not greater than 0.2. The present invention provides an injection mechanism, which uses CFD software to perform three-dimensional flow calculations on nozzle flow channels with different geometric parameters, and uses flow loss as the main criterion to calculate and evaluate hydraulic efficiency, and provides a needle size with the best efficiency, so that even if the needle tip 603 falls off, the hydraulic performance is less affected, thereby solving the problem of the needle tip 603 falling off due to the impact of mud and sand particles in the injection mechanism, resulting in a decrease in hydraulic performance, and can improve the economic benefits of the operation of the turbine unit; in the case of severe wear of the needle tip 603, since the needle tip 603 can be detachably mounted on the needle body 602, the needle tip 603 can be easily disassembled and replaced, thereby ensuring the performance of the needle assembly 600.

[0056] In one embodiment of the present invention, the spray needle assembly 600 further includes: a connector 604, one end of which is fixed on the support plate 601, and the other end of the connector 604 is movably connected to the spray needle body 602, and a driving mechanism is provided inside the connector 604 for driving the spray needle body 602 and the spray needle tip 603 to move along the extension direction of the straight pipe section 500. In this embodiment, the connector 604 is a structure connected between the spray needle body 602 and the support plate 601, and its radial dimension is larger than that of the spray needle tip 603. If the spray needle tip 603 is a pointed structure, the connector 604 is a blunt structure, and a driving mechanism is provided inside the connector 604 for pushing and pulling the spray needle body 602 and the spray needle tip 603 to move along the extension direction of the straight pipe section 500, thereby adjusting the injection flow rate. Optionally, the connector 604 can be a push rod structure, which is nested on the outside of the spray needle body 602, such as Figure 4 In the illustrated embodiment, it can be used to drive the needle body 602 and the needle tip 603 to move leftward or rightward.

[0057] In one embodiment of the present invention, the other end of the needle body 602 is formed with an internal thread, and the end of the needle tip 603 close to the needle body 602 is formed with an external thread that matches the internal thread, and the needle body 602 and the needle tip 603 are connected by threads. In this embodiment, the needle body 602 and the needle tip 603 are connected by a threaded structure, and can be disassembled or installed by rotating the needle tip 603. When the needle tip 603 has a serious wear problem, the needle tip 603 is unscrewed from the needle body 602 and replaced with a new needle body 602. In this embodiment, the internal and external thread structures are used to achieve a detachable connection between the needle body 602 and the needle tip 603, which is convenient for replacing the needle tip 603.

[0058] In one embodiment of the present invention, a slot is formed at the other end of the needle body 602, and a protrusion that matches the slot is formed at one end of the needle tip 603 close to the needle body 602, so that the needle body 602 and the needle tip 603 are connected by snapping. In this embodiment, the threaded connection in the above embodiment can be replaced by a snap connection, and the needle tip 603 is installed on the needle body 602 by the snapping action between the slot and the protrusion. Preferably, the slot and the protrusion are both sawtooth structures, and the sawtooth structure is used to realize the snap connection between the two. When the needle tip 603 has a serious wear problem, the needle tip 603 is removed from the needle body 602 by applying sufficient external force. In order to facilitate the removal of the needle tip 603, a gap is left between the needle tip 603 and the needle body 602 when the needle tip 603 is installed, and the needle tip 603 can be removed by prying through the gap.

[0059] In one embodiment of the present invention, the tip of the spray needle tip 603 is angled a, and the value range of a is 50° to 70°. In this embodiment, by reasonably designing the tip angle of the spray needle tip 603, the wear of the sprayed fluid on the tip can be reduced and the spraying effect can be ensured.

[0060] In one embodiment of the present invention, the nozzle assembly 700 includes: a nozzle body 701, a sealing ring 703 and an expansion section 702. The nozzle body 701 is fixed at the opening of the straight pipe section 500; the expansion section 702 is arranged at the ejection end of the nozzle body 701. Furthermore, the inner wall of the nozzle body 701 has a stepped mounting surface, and the expansion section 702 is fixed to the ejection end of the nozzle body 701 through the stepped mounting surface; the sealing ring 703 is arranged between the expansion section 702 and the stepped mounting surface. In this embodiment, the liquid is ejected through the nozzle body 701, and a stepped mounting surface is processed on the inner wall of the nozzle body 701 for installing the expansion section 702. The expansion section 702 is located at the ejection position of the nozzle body 701, and the sealing ring 703 is used to seal this part to prevent liquid leakage.

[0061] In one embodiment of the present invention, the inward contraction angle of the ejection end of the nozzle body 701 is b, and the value range of b is a+(30~40)°. In this embodiment, the ejection position of the nozzle body 701 is an inward contraction section, and its angle is numerically related to the tip of the needle tip 603. The angle formed by the contraction section is greater than 30°~40° of the tip angle of the needle tip 603. By reasonably designing the angle of the ejection end of the nozzle body 701, the wear of the ejected fluid on the tip can be reduced and the ejection effect can be guaranteed.

[0062] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, i.e., may be located in one place, or may be distributed over multiple units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. Those of ordinary skill in the art may understand and implement the present invention without creative effort.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water distribution ring pipe with adjustable pitch diameter, characterized in that: include: The water distribution main pipe (100) is annular in structure and is arranged outside the runner (400); A water distribution branch pipe (200) is movably connected to the water distribution main pipe (100), the water distribution branch pipe (200) is arranged toward the impeller (400), and through the movably connected to the water distribution main pipe (100), the spraying direction of the water distribution branch pipe (200) is adjusted to match the impeller (400) with different pitch circle diameters.

2. The water distribution ring pipe with adjustable pitch diameter according to claim 1, characterized in that: Also includes: A flexible connector (300), wherein the water distribution branch pipe (200) is movably connected to the water distribution main pipe (100) via the flexible connector (300) so as to adjust the spraying direction of the water distribution branch pipe (200) to match the pitch circle diameters of different runners (400).

3. The water distribution ring pipe with adjustable pitch diameter according to claim 2, characterized in that: A plurality of the flexible connectors (300) are provided, the water distribution branch pipe (200) comprises a hard nozzle (201) and at least one hard connection pipe (202), the hard connection pipe (202) is connected to the water distribution main pipe (100) via the flexible connector (300), and the hard nozzle (201) and the hard connection pipe (202) are connected via the flexible connector (300).

4. The water distribution ring pipe with adjustable pitch diameter according to claim 3, characterized in that: A plurality of the hard connection tubes (202) are provided, and two adjacent hard connection tubes (202) are connected via the soft connection piece (300).

5. The water distribution ring pipe with adjustable pitch diameter according to claim 3, characterized in that: The hard connecting pipe (202) comprises: a first connecting pipe and a second connecting pipe located downstream of the water distribution main pipe (100), the first connecting pipe being connected to the three-way pipe of the water distribution main pipe (100), the soft connecting piece (300) being arranged between the first connecting pipe and the three-way pipe, and the soft connecting piece (300) being arranged between the second connecting pipe and the downstream of the water distribution main pipe (100).

6. The water distribution ring pipe with adjustable pitch diameter according to any one of claims 2 to 5, characterized in that: The adjustment angle of the flexible connector (300) has a value range of -5° to 5°.

7. The water distribution ring pipe with adjustable pitch diameter according to claim 1, characterized in that: The water distribution branch pipe (200) is a soft nozzle, and the angle between the soft nozzle and the water distribution main pipe (100) is adjusted so that the spraying direction of the soft nozzle matches the pitch circle diameters of different runners (400).

8. The water distribution ring pipe with adjustable pitch diameter according to any one of claims 1 to 7, characterized in that: A plurality of the water distribution branch pipes (200) are provided, and when a model test is performed on impulse turbines with different runner (400) pitch circle diameters, the adjustment angle of each of the water distribution branch pipes (200) is the same.

9. An impulse turbine system, characterized in that: include: A water distribution ring pipe with adjustable pitch diameter as described in any one of claims 1 to 8.

10. The impulse turbine system according to claim 9, characterized in that: Also includes: An injection mechanism, wherein the injection mechanism is arranged downstream of the water distribution branch pipe (200).

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