A special turbine for PIV experiment

Abstract

A special water turbine for PIV experiment, wherein the volute water inlet chamber comprises an upper light-transmitting water inlet chamber and a lower metal water inlet chamber, the light-transmitting water inlet chamber and the metal water inlet chamber are sealed and fixed together, a rear cover plate and a front cover plate are fixedly mounted on both sides of the volute water inlet chamber respectively, the inlet of the elbow-shaped water outlet chamber is fixedly connected to the front cover plate, a runner is mounted in the volute water inlet chamber, the runner is connected to one end of the main shaft, the other end of the main shaft passes through the elbow-shaped water outlet chamber and the shaft seal and is fixed to the bearings on the left and right sides of the bearing chamber, the volute water inlet chamber located at the water inlet of the runner is equipped with evenly distributed movable guide vanes, which are mounted on the front cover plate and the rear cover plate via a rotating shaft, one end of the movable guide vane extends out of the front cover plate and is connected to a guide vane linkage mechanism; the structure is novel and unique, the operation is convenient, the cost is low, and the PIV experimental conditions and requirements of the water turbine are met; the image acquisition instrument can be flexibly arranged at any position outside the rear cover plate, and the internal flow field of the runner can be collected and studied in a larger range, with significant social and economic benefits.

Description

Technical Field

[0001] The invention relates to a water turbine, in particular to a water turbine specially used for PIV experiments. Background Art

[0002] In the PIV experiment of a water turbine, a laser sheet light source is used to illuminate the flow field in the runner channel, causing tracer particles suspended in the water to scatter light. The image acquisition device can be used to study and analyze the internal flow field state by photographing the tracer particles that scatter the light. This is an effective way to study water turbines. However, due to structural deficiencies, in conventional water turbine layouts, structures such as the bearing chamber and the main shaft interfere with the placement of the image acquisition device and block light propagation, making photography difficult and limiting the research area that can be photographed. Therefore, there is an urgent need for a water turbine dedicated to PIV experiments to meet the conditions required for PIV experiments and avoid the problems of traditional water turbines in PIV experiments. Summary of the invention

[0003] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a special turbine for PIV experiments, which can effectively solve the problems of difficult placement of image acquisition instruments and easy obstruction of light leading to difficulty in shooting in PIV experiments.

[0004] To achieve the above-mentioned purpose, the technical solution provided by the present invention is a special water turbine for PIV experiment, comprising a volute water diversion chamber, a main shaft and a runner, wherein the volute water diversion chamber comprises an upper light-transmitting water diversion chamber and a lower metal water diversion chamber, the light-transmitting water diversion chamber and the metal water diversion chamber are sealed and fixed together by bolts, a rear cover plate and a front cover plate are fixedly mounted on both sides of the volute water diversion chamber respectively, the inlet of the elbow-type water outlet chamber is fixedly connected to the front cover plate, a runner is mounted in the volute water diversion chamber, the runner is connected to one end of the main shaft through a central threaded hole, the other end of the main shaft passes through the elbow-type water outlet chamber and the shaft seal along the outflow direction of the runner and is fixed together with the bearings on the left and right sides of the bearing chamber, one end of the main shaft extending out of the bearing chamber is connected to a dynamometer, and a uniformly distributed movable guide vane is mounted in the volute water diversion chamber at the water inlet of the runner, which is mounted on the front cover plate and the rear cover plate through a rotating shaft, and one end of the movable guide vane extends out of the front cover plate and is connected to a guide vane linkage mechanism.

[0005] The invention has a novel and unique structure, is easy to operate, and has a low cost. It meets the conditions and requirements of the PIV experiment of the turbine. The image acquisition instrument can be flexibly arranged at any position outside the rear cover plate to collect and study the internal flow field of the runner in a larger range, with significant social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a top view (partial cutaway view) of the structure of the present invention.

[0007] Figure 2 It is a left view of the structure of the present invention.

[0008] Figure 3It is a structural cross-sectional front view of the present invention.

[0009] Figure 4 It is a schematic diagram of the structure of the elbow type water outlet chamber of the present invention.

[0010] Figure 5 It is a structural diagram of the guide vane linkage mechanism of the present invention.

[0011] Figure 6 The present invention Figure 5 Top view of the center guide vane linkage mechanism.

[0012] Figure 7 The present invention Figure 5 Side view of the center guide vane linkage mechanism. DETAILED DESCRIPTION

[0013] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings and specific circumstances.

[0014] In conjunction with the accompanying drawings, a special turbine for PIV experiment is provided, including a volute water diversion chamber, a main shaft and a runner, the volute water diversion chamber 1 includes an upper light-transmitting water diversion chamber 1-1 and a lower metal water diversion chamber 1-2, the light-transmitting water diversion chamber 1-1 and the metal water diversion chamber 1-2 are sealed and fixed together by bolts, a rear cover plate 5 and a front cover plate 6 are fixedly installed on both sides of the volute water diversion chamber 1, the inlet of the elbow-type water outlet chamber 8 is fixedly connected to the front cover plate 6, and a runner 4 is installed in the volute water diversion chamber 1, The runner 4 is connected to one end of the main shaft 7 through a central threaded hole. The other end of the main shaft 7 passes through an elbow-shaped water outlet chamber 8 and a shaft seal 9 along the outflow direction of the runner 4 and is fixed together with the bearings 10 on the left and right sides of the bearing chamber 11. One end of the main shaft 7 extending out of the bearing chamber 11 is connected to a dynamometer. The volute water inlet chamber 1 at the water inlet of the runner 4 is equipped with uniformly distributed movable guide vanes 3, which are installed on the front cover plate 6 and the rear cover plate 5 through a rotating shaft. One end of the movable guide vane 3 extends out of the front cover plate 6 and is connected to a guide vane linkage mechanism 13.

[0015] To ensure better implementation effects, the outlet of the volute water diversion chamber 1 is provided with evenly distributed fixed guide vanes 2, and the fixed guide vanes 2 include light-transmitting fixed guide vanes 2-1 and metal fixed guide vanes 2-2, which are respectively located in the light-transmitting water diversion chamber 1-1 and the metal water diversion chamber 1-2 on the periphery of the movable guide vanes 3.

[0016] The runner 4, movable guide vanes 3 and rear cover plate 5 are all light-transmitting structures.

[0017] The rotating wheel 4 comprises an upper crown 4-1, a lower ring 4-3 and blades 4-2 evenly distributed between the upper crown 4-1 and the lower ring 4-3, a rear cover plate 5 is located on one side of the upper crown 4-1, and a front cover plate 6 is located on one side of the lower ring 4-3.

[0018] The bearing chamber 11 is mounted on a supporting base 12 at the bottom.

[0019] The runner 4 is a mixed flow runner, a pump turbine runner or a pump turbine runner.

[0020] The guide vane linkage mechanism 13 comprises a guide vane opening disk 13-1, a linkage arm 13-2, a transmission rod 13-3, a guide vane torsion arm 13-4 and a guide vane linkage ring 13-5. One end of the guide vane torsion arm 13-4 is fixedly connected to the transmission shaft of the movable guide vane 3, and the other end is hinged to the guide vane linkage ring 13-5. The guide vane linkage ring 13-5 is connected to the linkage arm 13-2 via the transmission rod 13-3. The scales of the opening disk 13-1 corresponding to the pointers at both ends of the linkage arm 13-2 are always consistent with the outlet angle of the movable guide vane 3. When the experimental working conditions are changed, a torque is applied to the linkage arm 13-2 to adjust the angle. The linkage arm 13-2 drives the guide vane linkage ring 13-5 to operate via the transmission rod 13-3, and the linkage ring 13-5 drives the torsion arm 13-4 to rotate to complete the opening adjustment of the movable guide vane 3.

[0021] When the present invention is in operation, the laser sheet light source is placed just above the water diversion chamber 1, and the image acquisition device is placed on the outside of the rear cover plate 5. The water flow containing the tracer particles enters from the inlet of the water diversion chamber 1, flows through the fixed guide vane 2 and the movable guide vane 3, pushes the impeller 4 to rotate and do work, and is finally discharged from the elbow-type water outlet chamber 8. The laser emitted by the laser sheet light source penetrates the upper transparent water diversion chamber 1-1, the transparent fixed guide vane 2-1 and the movable guide vane 3, and enters the internal flow channel of the impeller 4. The tracer particles irradiated by the laser scatter the light, and part of the scattered light penetrates the transparent upper crown 4-1 and the rear cover plate 5, and is captured by the image acquisition device to complete the shooting. The image acquisition device can be flexibly placed on the outside of the rear cover plate 5 without interference, which is convenient for collecting flow field information in a larger range for research.

[0022] The present invention has been used and tested in practice, and the effect is good. The relevant information is as follows:

[0023] A special turbine for PIV experiment, used for PIV experiment of Francis turbine, the model runner diameter D1 is 300mm, the unit is arranged horizontally, the upper water diversion chamber and the fixed guide vanes, movable guide vanes, runner and rear cover plate connected therein are all made of transparent resin glass, and other main parts are made of metal. The runner is connected to one end of the main shaft through threads and is tightened with a pressure ring. After the main shaft passes through the elbow tailwater pipe, machine seal and bearing chamber along the water outlet direction of the runner, the shaft extension section is connected to the magnetic particle distance meter through a flange, the experimental head range is less than 15m, and the flow range is less than 150m 3 / h, the speed range is lower than 800r / min, and the experimental working condition adjustment can be achieved through the guide vane linkage mechanism. During the experiment, the laser sheet light source is located directly above the water diversion chamber, and the CCD camera is arranged vertically on the side of the rear cover. The laser from the sheet light source penetrates the water diversion chamber, fixed guide vanes, and movable guide vanes made of resin glass and enters the internal flow channel of the runner. The silicon powder suspended in the water serves as tracer particles and scatters light that penetrates the crown and rear cover of the runner and enters the CCD camera. Shooting the light scattered by the tracer particles can reflect the real flow field information. During the experiment, the CCD camera is not disturbed, and the internal flow field illuminated by the sheet light source can effectively collect images.

[0024] The invention has a novel and unique structure and is easy to operate. Compared with the prior art, it has the following advantages:

[0025] (1) It meets the conditions and purpose of the turbine PIV test, facilitates the collection of flow field information in a larger range for research, and avoids the problems of conventional turbine structure interfering with the placement of the image acquisition instrument, blocking light propagation, and affecting the experimental results by breaking the conventional turbine structure layout;

[0026] (2) By dividing the water diversion chamber into two parts and using light-transmitting materials and metal materials respectively, it can not only meet the light transmission requirements of the experiment, but also avoid the problem of insufficient rigidity caused by using all non-metallic materials, and meet the stable operation during the experiment;

[0027] (3) The crown side of the turbine is a plane, which greatly increases the area in the flow channel where flow field images can be collected, which is conducive to collecting and studying the internal flow field of the runner in a larger range;

[0028] (4) The guide vane linkage mechanism can realize the adjustment of the experimental working conditions and facilitate the observation of the actual angle of the movable guide vane outlet, and can accurately and quickly find the experimental working conditions;

[0029] (5) The use of the present invention in PIV experiments on water turbines provides convenient conditions and possibilities for experimental research on the internal flow field of water turbines. The structure of the present invention can be widely used in PIV research on mixed flow turbines, pump turbines, centrifugal pumps and other radial turbines, with significant social and economic benefits.

Claims

1. A special hydraulic turbine for PIV experiment, comprising a volute water diversion chamber, a main shaft and a runner, characterized in that: The volute water inlet chamber (1) comprises an upper light-transmitting water inlet chamber (1-1) and a lower metal water inlet chamber (1-2). The light-transmitting water inlet chamber (1-1) and the metal water inlet chamber (1-2) are sealed and fixed together by bolts. A rear cover plate (5) and a front cover plate (6) are fixedly installed on both sides of the volute water inlet chamber (1). The inlet of the elbow-shaped water outlet chamber (8) is fixedly connected to the front cover plate (6). A runner (4) is installed in the volute water inlet chamber (1). The runner (4) is connected to one end of the main shaft (7) through a central threaded hole. The other end of the shaft (7) passes through the elbow-shaped water outlet chamber (8) and the shaft seal (9) along the outflow direction of the runner (4) and is fixed together with the bearings (10) on the left and right sides of the bearing chamber (11). One end of the main shaft (7) extending out of the bearing chamber (11) is connected to a dynamometer. A volute water inlet chamber (1) located at the water inlet of the runner (4) is provided with uniformly distributed movable guide vanes (3) which are mounted on the front cover plate (6) and the rear cover plate (5) via a rotating shaft. One end of the movable guide vane (3) extends out of the front cover plate (6) and is connected to a guide vane linkage mechanism (13). The outlet of the volute water diversion chamber (1) is provided with uniformly distributed fixed guide vanes (2), the fixed guide vanes (2) comprising light-transmitting fixed guide vanes (2-1) and metal fixed guide vanes (2-2), which are respectively located in the light-transmitting water diversion chamber (1-1) and the metal water diversion chamber (1-2) on the periphery of the movable guide vanes (3); The impeller (4), movable guide vanes (3) and rear cover plate (5) are all light-transmitting structures; The rotating wheel (4) comprises an upper crown (4-1), a lower ring (4-3) and blades (4-2) evenly arranged between the upper crown (4-1) and the lower ring (4-3); a rear cover plate (5) is located on one side of the upper crown (4-1) and a front cover plate (6) is located on one side of the lower ring (4-3).

2. The PIV experiment dedicated water turbine according to claim 1, characterized in that: The bearing chamber (11) is mounted below on a supporting base (12).

3. The PIV experiment dedicated water turbine according to claim 1, characterized in that: The runner (4) is a type of mixed flow runner, a pump turbine runner or a pump turbine runner.

4. The PIV experiment dedicated water turbine according to claim 1, characterized in that: The guide vane linkage mechanism (13) comprises a guide vane opening disk (13-1), a linkage arm (13-2), a transmission rod (13-3), a guide vane torsion arm (13-4) and a guide vane linkage ring (13-5); one end of the guide vane torsion arm (13-4) is fixedly connected to the transmission shaft of the movable guide vane (3), and the other end is hinged to the guide vane linkage ring (13-5); the guide vane linkage ring (13-5) is connected to the linkage arm (13-2) via the transmission rod (13-3); the scales of the opening disk (13-1) pointed to by the pointers at both ends of the linkage arm (13-2) are always consistent with the outlet angle of the movable guide vane (3); when the experimental working condition is changed, a torque is applied to the linkage arm (13-2) to adjust the angle; the linkage arm (13-2) drives the guide vane linkage ring (13-5) to operate via the transmission rod (13-3); and the linkage ring (13-5) drives the guide vane torsion arm (13-4) to rotate to complete the opening adjustment of the movable guide vane (3).

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