A runner oil pressure balance test system and method

Abstract

The present application relates to the technical field of hydroelectric generating set equipment testing, in particular to a runner oil pressure balance testing system and method, which provides a double-oil-path independent balance testing structure in the system part, forms an independent oil pressure testing cavity in the outer cover through the split design of the outer cover and the inner cover, realizes the complete separation of the outer operation sealing oil pressure and the inner operation driving oil pressure, avoids the mutual interference of the two oil pressures, can independently detect the sealing pressure balance performance of the outer operation system and the action driving balance performance of the inner operation system respectively, verifies the oil pressure balance and sealing performance of the testing system itself before testing the runner in the method part, determines the pressure drop threshold and pressure fluctuation range allowed by the system, eliminates the interference of the imbalance and leakage of the tool itself on the test result, eliminates the subjective error of manual judgment through the quantitative indexes such as the specified pressure increasing rate and the synchronous deviation of the two pressure paths, realizes the standardization and repeatable detection of the oil pressure balance performance.

Description

Technical Field

[0001] This invention relates to the field of dynamic balancing testing technology for hydropower equipment, specifically a turbine runner hydraulic pressure balancing testing system. Background Technology

[0002] The turbine runner is the core rotating component in hydroelectric power generation equipment that converts water flow energy into mechanical energy. Its dynamic balance performance directly determines the unit's operational stability, vibration level, and service life. Currently, the industry generally schedules the runner dynamic balance test after the entire machine is assembled. The unbalanced mass forces are detected and eliminated through the overall dynamic balance test. However, this post-processing method has significant drawbacks: when problems such as unbalanced movement or uneven sealing pressure are found in the runner under hydraulic drive, it is necessary to repeatedly disassemble the top cover and lift out the runner for rework and adjustment. This not only significantly increases construction costs and time, but may also damage the assembly precision of the runner due to repeated disassembly and reassembly.

[0003] In fact, the imbalance of hydraulic drive after the turbine runner is processed and assembled is an important precursor to the dynamic imbalance in subsequent operation. This includes periodic alternating forces caused by asynchronous blade movement, eccentric load torque caused by uneven sealing pressure, and impact loads caused by oil circuit pressure fluctuations. These hydraulic imbalance defects cannot be detected by traditional quality dynamic balancing tests, but they will be transformed into additional dynamic imbalance forces during unit operation, causing malfunctions such as excessive unit vibration and accelerated bearing wear.

[0004] Existing hydraulic runner testing devices and methods mainly focus on testing sealing performance, servo travel and blade angle, without taking hydraulic balance performance as an independent core testing indicator.

[0005] At the device level, most adopt an integrated customized structure, which has poor versatility and is difficult to guarantee coaxiality. During testing, it is easy to generate additional stress and uneven load. In addition, the sealing structure is mostly of a single form, and the sealing contact pressure may be unevenly distributed. The tooling itself leakage and pressure imbalance will seriously interfere with the test results. There is a lack of independent internal and external operating oil circuit design, and it is impossible to isolate and test the balance performance of the internal operating drive system and the external operating sealing system separately.

[0006] At the methodological level, manual valve control and manual reading are commonly used, lacking quantitative balance judgment standards. This makes it impossible to identify minor imbalance defects such as asynchronous blade movement and uneven sealing pressure. The test process does not include a system self-balance pre-verification step, making it impossible to distinguish between tooling imbalance and impeller body imbalance. As a result, the reliability of the test results is not ideal, and it is difficult to effectively identify potential assembly hazards that may cause dynamic imbalance in the future. Summary of the Invention

[0007] The purpose of this invention is to provide a hydraulic pressure balance testing system and method for a turbine, addressing the aforementioned problems.

[0008] The technical solution adopted in this invention is as follows: a rotary oil pressure balance test system, including an outer cover and an inner cover, wherein the outer cover is detachably connected to the rotary body, one end of the inner cover is connected to the inner core of the rotary body, wherein an oil pressure test chamber is provided inside the outer cover, a first oil inlet is provided on one side of the outer cover and the first oil inlet is connected to the oil pressure test chamber, and a first sealing connection structure is provided at the connection between the outer cover and the rotary body.

[0009] The inner cover is located inside the hydraulic test chamber, and the other end of the inner cover is connected to the inner operating oil inlet core, and the inner operating oil inlet core is connected to the inner core of the rotor body.

[0010] Furthermore, the outer cover is cylindrical, and a circular protrusion is provided on the top of the outer cover, which is connected to the rotating wheel body through the circular protrusion.

[0011] The first sealing connection structure includes a first bolt, a first gasket, and a first O-ring;

[0012] The first bolt passes through the first washer, the annular protrusion, and the rotating body;

[0013] The first O-ring is located on the side of the annular protrusion facing the wheel body, and the center of the first O-ring overlaps with the center of the annular protrusion. The first O-ring is closer to the center of the annular protrusion than the first sealing connection structure.

[0014] A second O-ring is provided on the inner ring of the protruding part of the circular ring, and the second O-ring fits into the part of the wheel body that is inserted into the inner ring of the protruding part of the circular ring.

[0015] Furthermore, a transition flange is connected to the inner cover, and the transition flange is connected to the inner core of the rotor.

[0016] The transition flange is connected to the inner core of the rotor body by a second bolt, and the transition flange is connected to the inner cover by a connecting nut, with the connecting nut located between the center of the transition flange and the second bolt.

[0017] Furthermore, the inner cover is provided with a third O-ring seal, which is located on the side of the inner cover facing the transition flange, and the center of the third O-ring seal coincides with the center line of the inner cover.

[0018] Furthermore, a cover plate is provided at the bottom of the outer casing's cylinder, and the inner oil inlet core passes through the outer casing and the cover plate;

[0019] The cover plate is detachably connected to the outer cover by a third bolt. A fourth O-ring is provided on the cover plate, and the fourth O-ring is fitted around the outer periphery of the inner oil inlet core.

[0020] This application also provides a matching method for testing the hydraulic pressure balance of a turbine runner based on a turbine runner hydraulic pressure balance test system. This method is used to detect the operational balance of the turbine runner under hydraulic pressure, and includes the following steps:

[0021] S1. Pre-test preparation and system verification: complete the test pipeline connection and sensor calibration, and confirm that all valves are closed to ensure that the initial state of the rotor oil pressure balance test system is balanced.

[0022] S2. Pre-verification of hydraulic pressure balance of the test system: Hydraulic oil is introduced into the hydraulic pressure balance test system of the impeller, and multi-stage pressure holding test is carried out using the graded pressure increase method. The hydraulic pressure balance and sealing performance of the impeller hydraulic pressure balance test system itself are determined based on the pressure drop value.

[0023] S3. Independent operation balance test of internal operating oil circuit: Hydraulic oil is introduced into the internal operating oil circuit of the impeller separately, and low-pressure no-load balance break-in, graded load balance test and limit stroke balance verification are carried out in sequence. The synchronization and uniformity of blade movement are collected and analyzed.

[0024] S4. Independent sealing balance test of external operating oil circuit: The rated test pressure is introduced into the oil pressure balance test system of the impeller separately, and the sealing pressure balance performance of the impeller body is determined by long-term pressure holding test.

[0025] S5. Combined hydraulic pressure balance test of internal and external operation: Rated working pressure is simultaneously supplied to the internal and external operation hydraulic circuits to conduct full stroke reciprocating motion balance test and multi-position pressure holding balance test to verify the overall hydraulic pressure balance performance of the impeller.

[0026] S6. Intelligent graded pressure relief and balance data management: Depressurizes in stages according to preset rates, drains residual oil, automatically stores all balance test data and generates traceable electronic reports.

[0027] Furthermore, step S2 includes the following sub-steps:

[0028] S2.1. Open the external control oil inlet valve and close the internal control oil inlet and drain valves;

[0029] S2.2. The pressure is increased sequentially to 0.5MPa, 2MPa and 4MPa at a constant rate. The pressure is automatically maintained for 10 minutes at each pressure level. The pressure fluctuation during the pressure holding period is less than the set pressure fluctuation value to ensure uniform oil pressure distribution in the test system.

[0030] S2.3. Increase the pressure to the rated test pressure, maintain the pressure automatically for 30 minutes, and calculate the balanced pressure drop value of the test system. :

[0031] ;

[0032] in, To maintain the initial pressure, This is the pressure after holding the pressure for 30 minutes;

[0033] like If the oil pressure is below the set threshold and there is no visible leakage, the oil pressure balance of the test system is deemed qualified.

[0034] Furthermore, step S3 includes the following sub-steps:

[0035] S3.1. Keep the external operating oil circuit closed and open the internal operating oil inlet valve;

[0036] S3.2. Low-pressure no-load balance break-in: introduce low-pressure hydraulic oil and control all blades of the impeller to reciprocate synchronously within the full stroke range. The allowable deviation of the single blade action time is less than the set design value.

[0037] S3.3. Graded load balance test: the pressure is increased sequentially to 2MPa, 4MPa and rated working pressure, and the blades are controlled to complete the full stroke synchronous action under each pressure level;

[0038] S3.4. Limit stroke balance verification: drive all blades synchronously to the fully open and fully closed limit positions, and maintain pressure for 5 minutes. The allowable value of pressure drop in the internal operating oil circuit is less than the set allowable value, the displacement change at the limit position is less than the set limit displacement, and confirm that there is no off-center load interference.

[0039] Furthermore, step S4 includes the following sub-steps:

[0040] S4.1. Close the internal operating oil circuit, fix all blades of the runner body in the middle balance position, and introduce the rated test pressure into the runner oil pressure balance test system;

[0041] S4.2. Automatically maintain pressure for 60 minutes, record the pressure value every 10 minutes, and calculate the total pressure drop value of the impeller body seal balance. :

[0042] ;

[0043] in, To maintain the initial pressure, This is the pressure after holding the pressure for 60 minutes;

[0044] S4.3.If If the leakage is less than the set threshold and there is no visible leakage, the impeller body seal balance is deemed qualified.

[0045] Furthermore, step S5 includes the following sub-steps:

[0046] S5.1. Simultaneously supply rated working pressure to the internal and external operating oil circuits, control the synchronous deviation of the two pressures to be less than the set deviation threshold, and simulate the oil pressure balance condition of the actual operation of the impeller.

[0047] S5.2. Control all blades of the rotor to continuously and synchronously reciprocate throughout the entire stroke range;

[0048] S5.3. Fix the impeller blades in three balanced positions: fully open, fully closed, and intermediate, and maintain pressure for 15 minutes. Monitor the uniformity of pressure distribution throughout the process. After the pressure holding period, automatically generate a report indicating whether the balance performance is qualified or unqualified.

[0049] The beneficial effects of the present invention include at least one of the following;

[0050] 1. The system provides a dual-oil-circuit independent balance test structure. Through the split design of the outer and inner covers, an independent oil pressure test chamber is formed inside the outer cover, realizing the complete separation of the external control sealing oil pressure and the internal control drive oil pressure, avoiding mutual interference between the two oil pressures. It can independently test the sealing pressure balance performance of the external control system and the motion drive balance performance of the internal control system. Furthermore, it adopts a combination of a first O-ring axial seal and a second O-ring radial seal, with the seals evenly arranged along the circumference and the sealing contact pressure evenly distributed. This not only ensures the sealing reliability under high oil pressure, but also eliminates the off-center load torque caused by uneven sealing pressure of the tooling itself, avoiding interference of tooling sealing imbalance on the wheel balance test results.

[0051] 2. The inner cover is detachably connected to the inner core of the rotor via a transition flange. The transition flange can be adapted and replaced according to different rotor specifications, while ensuring the coaxiality of the inner cover and the inner core of the rotor. This allows the driving force of the internal operating oil circuit to be evenly transmitted to all blades, avoiding asynchronous blade movement and unbalanced force due to coaxiality deviation. The bottom of the outer cover adopts a detachable cover plate structure. The cover plate is connected to the outer cover by evenly distributed third bolts, ensuring that the hydraulic pressure test chamber is subjected to balanced force under high pressure and avoiding local deformation. The fourth O-ring on the cover plate achieves dynamic sealing of the inner operating oil inlet core, ensuring the sealing of the internal operating oil circuit without affecting the normal movement of the inner operating oil inlet core with the rotor core, thus ensuring the accuracy of the action test.

[0052] 3. Before testing the impeller in the methodology section, the hydraulic pressure balance and sealing performance of the testing system are verified through a graded pressure increase and holding test. This clarifies the system's allowable pressure drop threshold and pressure fluctuation range, eliminating interference from tooling imbalances and leaks on the test results. A step-by-step process is adopted, consisting of independent testing of internal operation balance, independent testing of external operation sealing balance, and comprehensive testing of combined balance. First, the synchronization and uniformity of the movement of all blades are tested separately, and then the uniformity of the sealing pressure distribution of the impeller body is tested separately. This allows for precise identification of the specific factors causing hydraulic pressure imbalance, providing a clear direction for subsequent assembly adjustments and avoiding unnecessary rework.

[0053] 4. By defining quantitative indicators such as pressurization rate, pressure holding time, allowable pressure drop, blade movement synchronization deviation, and two-way pressure synchronization deviation, subjective errors caused by manual judgment are eliminated. This achieves standardized and repeatable testing of hydraulic pressure balance performance, enabling precise identification of minute imbalance defects that cannot be detected by traditional methods. Furthermore, by simultaneously supplying rated working pressure to the internal and external operating oil circuits, the actual hydraulic pressure conditions of the turbine runner are accurately simulated. Full-stroke reciprocating motion balance tests and multi-position pressure holding balance tests are conducted, revealing internal and external oil circuit coordination imbalances that cannot be detected by individual tests, thus comprehensively verifying the overall hydraulic pressure balance performance of the turbine runner. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of a rotary hydraulic pressure balance testing system.

[0055] Figure 2 This is a schematic diagram of the piping connection of a rotary hydraulic pressure balance test system;

[0056] Figure 3 This is a schematic diagram of the circular protrusion structure;

[0057] Figure 4 This is a flowchart of a method for testing the hydraulic pressure balance of a rotary drum.

[0058] In the picture:

[0059] 1 is the first O-ring seal, 2 is the outer cover, 3 is the first bolt, 4 is the first gasket, 5 is the second O-ring seal, 6 is the connecting nut, 7 is the inner cover, 9 is the transition flange, 10 is the second bolt, 11 is the third O-ring seal, 12 is the fourth O-ring seal, 13 is the third bolt, 14 is the cover plate, 15 is the inner oil inlet core, 16 is the oil pressure test chamber, 17 is the inner core of the rotor body, 18 is the circular protrusion, 101 is a group of first ball valves, 102 is a group of second ball valves, 201 is a group of two first ball valves, and 202 is a group of two second ball valves. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described in the accompanying drawings can generally be arranged and designed in various different configurations.

[0061] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0062] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0063] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0064] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0065] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0066] like Figure 1 and Figure 3As shown, a rotary oil pressure balance test system includes an outer cover 2 and an inner cover 7. The outer cover 2 is detachably connected to the rotary body, and one end of the inner cover 7 is connected to the inner core 17 of the rotary body. The outer cover 2 is provided with an oil pressure test chamber 16. A first oil inlet is provided on one side of the outer cover 2 and communicates with the oil pressure test chamber 16. A first sealing connection structure is provided at the connection between the outer cover 2 and the rotary body.

[0067] The inner cover 7 is located inside the hydraulic test chamber 16. The other end of the inner cover 7 is connected to the inner operating oil inlet core 15, and the inner operating oil inlet core 15 is connected to the inner core 17 of the rotating wheel.

[0068] The purpose of this design is to create an independent hydraulic pressure test chamber inside the outer cover by using a split structure of the outer and inner covers. The outer cover is detachably connected to the rotor body, and one end of the inner cover is connected to the inner core of the rotor body, while the other end is connected to the inner control oil inlet core. This enables independent control and testing of the external and internal control hydraulic pressure, which can simulate the hydraulic pressure environment during actual operation of the rotor and comprehensively test the core design indicators such as the relay stroke, blade angle, rotational flexibility, and sealing performance.

[0069] Meanwhile, in this embodiment, the outer cover 2 is cylindrical, and the top of the outer cover 2 is provided with a circular protrusion 18, which is connected to the rotating wheel body through the circular protrusion 18.

[0070] The purpose of this design is that the outer cover adopts a cylindrical structure with a circular protrusion at the top, which connects to the rotating wheel body. The structure is simple and has high connection strength, which can stably withstand the radial and axial loads during high-pressure testing and avoid deformation of the outer cover from affecting the test accuracy.

[0071] In this embodiment, the first sealing connection structure includes a first bolt 3, a first gasket 4, and a first O-ring 1;

[0072] The first bolt 3 passes through the first washer 4, the annular protrusion 18, and the rotating wheel body;

[0073] The first O-ring 1 is disposed on the side of the annular protrusion 18 facing the wheel body, and the center of the first O-ring 1 overlaps with the center of the annular protrusion 18. The first O-ring 1 is closer to the center of the annular protrusion 18 than the first sealing connection structure.

[0074] The purpose of this design is that the first sealing connection structure adopts a combination of a first bolt, a first gasket, and a first O-ring. The first O-ring is located on the side of the annular protrusion facing the wheel body and closer to the center, which achieves axial sealing at the connection between the outer cover and the wheel body. The bolt tightening force is evenly distributed, and the gasket can compensate for the slight unevenness of the connection surface, which significantly improves the reliability of the axial seal.

[0075] Meanwhile, in this embodiment, a second O-ring 5 is provided on the inner ring of the annular protrusion 18, and the second O-ring 5 is in contact with the part of the wheel body inserted into the inner ring of the annular protrusion 18.

[0076] The purpose of this design is to install a second O-ring seal on the inner ring of the protruding part of the circular ring, which fits into the part of the wheel body inserted into the inner ring of the protruding part of the circular ring to form a radial seal. Together with the previous axial seal, it forms a double sealing system, which further blocks the circumferential leakage path. There is no leakage under high oil pressure conditions, which effectively avoids the interference of the tooling itself on the test results.

[0077] Meanwhile, in this embodiment, a transition flange 9 is connected to the inner cover 7, and the transition flange 9 is connected to the inner core 17 of the rotor.

[0078] The purpose of this design is that the inner cover is connected to the inner core of the rotor through a transition flange. The transition flange can be used as an adapter component to facilitate replacement according to the inner core size of different rotor specifications, thereby improving the versatility of the device. At the same time, it ensures the coaxiality of the inner cover and the inner core of the rotor, ensuring that the oil inlet channel of the inner operating device is unobstructed.

[0079] In this embodiment, the transition flange 9 is connected to the inner core 17 of the rotor body by the second bolt 10, and the transition flange 9 is connected to the inner cover 7 by the connecting nut 6. The connecting nut 6 is located between the center of the transition flange 9 and the second bolt 10. The inner cover 7 is provided with a third O-ring seal 11, and the third O-ring seal 11 is located on the side of the inner cover 7 facing the transition flange 9. The center of the third O-ring seal 11 coincides with the center line of the inner cover 7.

[0080] The purpose of this design is to connect the transition flange to the inner core of the impeller via the second bolt and to the inner cover via the connecting nut, with the connecting nut located between the center of the transition flange and the second bolt. This connection method is flexible and reliable, easy to assemble and disassemble, and has a reasonable stress distribution, avoiding local stress concentration. It also facilitates adjustment of the axial position of the inner cover. A third O-ring is installed on the side of the inner cover facing the transition flange, with its center coinciding with the centerline of the inner cover. This achieves axial sealing at the connection between the inner cover and the transition flange, effectively preventing internal operating oil pressure leakage, ensuring stable internal operating oil circuit pressure, and improving the accuracy of internal operating action testing.

[0081] In this embodiment, a cover plate 14 is provided at the bottom of the cylinder of the outer cover 2, and the inner operating oil inlet core 15 passes through the outer cover 2 and the cover plate 14. The cover plate 14 is detachably connected to the outer cover 2 by a third bolt 13. A fourth O-ring seal 12 is provided on the cover plate 14, and the fourth O-ring seal 12 is fitted around the outer periphery of the inner operating oil inlet core 15.

[0082] The purpose of this design is that the cover plate is detachably connected to the outer cover by the third bolt, which is a firm connection and easy to disassemble and assemble. A fourth O-ring is set on the cover plate to fit around the outer circumference of the inner operating oil inlet core, which realizes dynamic sealing between the inner operating oil inlet core and the cover plate. This ensures the sealing of the inner operating oil inlet channel during the test process without affecting the normal axial movement of the inner operating oil inlet core with the inner core of the rotating wheel.

[0083] like Figure 2 As shown, a pipeline connection diagram of a rotary oil pressure balance test system is provided, wherein the main oil inlet and branches: the main oil inlet pipe serves as the main input channel for high-pressure oil, and is divided into two independent branches at the front end of the device, namely the internal control oil inlet pipe and the external control oil inlet pipe, so as to realize the independent supply and control of the external control oil pressure and the internal control oil pressure.

[0084] Internal control oil inlet pipeline: A set of ball valve 101 and a set of ball valve 102 are connected in series along the internal control oil inlet pipeline, and a pressure gauge is installed in the pipeline. The set of ball valve 101 and the set of ball valve 102 are used for staged control of the on / off state and flow regulation of the internal control oil circuit, and the pressure gauge is used to monitor the working pressure of the internal control oil circuit in real time, corresponding to the oil pressure action of the drive impeller core.

[0085] External control oil inlet pipeline: Two sets of No. 1 ball valves 201 and two sets of No. 2 ball valves 202 are connected in series along the external control oil inlet pipeline, and a No. 2 pressure gauge is installed in the pipeline. The two sets of No. 1 ball valves 201 and the two sets of No. 2 ball valves 202 are used for staged control of the opening and closing of the external control oil circuit and flow regulation, and the No. 2 pressure gauge is used to monitor the working pressure of the external control oil circuit in real time, and correspondingly drive the oil pressure action of the oil pressure test chamber inside the outer casing.

[0086] Oil drain line: A separate oil drain line is provided, and a first ball valve is installed on the line to safely drain the residual high-pressure oil inside the device and the impeller after the test is completed, so as to realize the pressure relief and emptying of the oil circuit.

[0087] It should be pointed out that in Figure 1 and Figure 2 The symbol “G1” indicates the size of a pipe fitting, where “G” represents a cylindrical pipe thread and “1” represents a size of 1 inch. It is a common symbol in pipe design.

[0088] like Figure 4 As shown, this embodiment provides a method for testing the hydraulic balance of a turbine runner, used to detect the operational balance of the turbine runner under hydraulic pressure, including the following steps:

[0089] S1. Pre-test preparation and system verification: complete the test pipeline connection and sensor calibration, and confirm that all valves are closed to ensure that the initial state of the rotor oil pressure balance test system is balanced.

[0090] S2. Pre-verification of hydraulic pressure balance of the test system: Hydraulic oil is introduced into the hydraulic pressure balance test system of the impeller, and multi-stage pressure holding test is carried out using the graded pressure increase method. The hydraulic pressure balance and sealing performance of the impeller hydraulic pressure balance test system itself are determined based on the pressure drop value.

[0091] S3. Independent operation balance test of internal operating oil circuit: Hydraulic oil is introduced into the internal operating oil circuit of the impeller separately, and low-pressure no-load balance break-in, graded load balance test and limit stroke balance verification are carried out in sequence. The synchronization and uniformity of blade movement are collected and analyzed.

[0092] S4. Independent sealing balance test of external operating oil circuit: The rated test pressure is introduced into the oil pressure balance test system of the impeller separately, and the sealing pressure balance performance of the impeller body is determined by long-term pressure holding test.

[0093] S5. Combined hydraulic pressure balance test of internal and external operation: Rated working pressure is simultaneously supplied to the internal and external operation hydraulic circuits to conduct full stroke reciprocating motion balance test and multi-position pressure holding balance test to verify the overall hydraulic pressure balance performance of the impeller.

[0094] S6. Intelligent graded pressure relief and balance data management: Depressurizes in stages according to preset rates, drains residual oil, automatically stores all balance test data and generates traceable electronic reports.

[0095] The purpose of this design is to first verify the oil pressure balance and sealing performance of the test system itself through a graded pressure increase and holding test, clarify the allowable pressure drop threshold and pressure fluctuation range of the system, eliminate the interference of tooling imbalance and leakage on the test results, and adopt a step-by-step process of independent testing of internal operation balance, independent testing of external operation sealing balance, and joint balance comprehensive testing. First, the synchronization and uniformity of the operation of all blades are tested separately, and then the uniformity of sealing pressure distribution of the impeller body is tested separately. This can accurately locate the specific link that causes oil pressure imbalance, provide a clear direction for subsequent assembly and adjustment, and avoid blind rework.

[0096] It should be noted that in order to obtain the parameters required for the oil pressure balance test of the rotor, the oil pressure balance test system is also equipped with existing data acquisition components such as pressure sensors, displacement sensors, angle sensors, and vibration sensors. Typically, the pressure sensor has a range of 0-10MPa, the displacement sensor has a range of 0-500mm, the angle sensor has a range of -30° to +30°, and the vibration sensor has a range of 0-10mm / s.

[0097] For the S1 section, unified sensor calibration ensures the measurement accuracy and consistency of data such as pressure, displacement, angle, and vibration, providing a reliable basis for subsequent quantitative balance determination; confirm that all valves are in the closed state to avoid uneven force caused by initial oil pressure leakage; ensure the mechanical balance of the test system in the initial state and eliminate interference from non-test factors such as pipeline twisting and tooling installation misalignment on balance performance.

[0098] In its specific implementation, S2 includes the following sub-steps:

[0099] S2.1. Open the external control oil inlet valve and close the internal control oil inlet and drain valves;

[0100] S2.2. The pressure is increased sequentially to 0.5MPa, 2MPa and 4MPa at a constant rate of 0.2MPa / min. The pressure is automatically maintained for 10min at each pressure level. The pressure fluctuation during the holding period is allowed to be ≤±0.02MPa to ensure uniform oil pressure distribution in the test system.

[0101] S2.3. Increase the pressure to the rated test pressure of 6.3 MPa, maintain the pressure automatically for 30 minutes, and calculate the equilibrium pressure drop of the test system. :

[0102] ;

[0103] in, To maintain the initial pressure, This is the pressure after holding the pressure for 30 minutes;

[0104] like If the oil pressure is below the set threshold and there is no visible leakage, the oil pressure balance of the test system is deemed qualified.

[0105] Furthermore, in S2.2, an incremental PID algorithm is used for closed-loop control of oil pressure balance, with the control quantity incrementing. The calculation formula is:

[0106] ;

[0107] in, This is a proportionality coefficient, with a value ranging from 2.0 to 3.0. This is the integral coefficient, with a value ranging from 0.1 to 0.2. These are the differential coefficients, with values ​​ranging from 0.05 to 0.1. The pressure deviation value at the k-th sampling time. The change in pressure deviation at the k-th sampling time. Let k be the second-order change in the pressure deviation at the k-th sampling time, where k is the sampling time number.

[0108] The purpose of this design is to verify the oil pressure balance performance of the test system itself before the impeller participates in the test. By simulating the gradual deformation process of the seal through graded pressure increase and holding, the leakage of all sealing points of the tooling is detected, the allowable pressure drop threshold and pressure fluctuation range of the system itself are clarified, and quantitative standards are established. Only when the system itself is balanced can it enter the impeller test stage, ensuring that all subsequent test data only reflect the balance performance of the impeller itself.

[0109] In its specific implementation, S3 includes the following sub-steps:

[0110] S3.1. Keep the external operating oil circuit closed and open the internal operating oil inlet valve;

[0111] S3.2. Low-pressure no-load balancing break-in: Introduce 1.0MPa low-pressure hydraulic oil and control all blades of the impeller to reciprocate synchronously throughout the entire stroke range. The allowable deviation of the single blade action time is ≤±10% of the design value, and the time difference between adjacent blade actions is ≤0.2s. If any jamming or abnormal vibration (vibration amplitude ≥0.5mm / s) is detected, the action will stop immediately and the pressure will be automatically released.

[0112] S3.3. Graded load balance test: the pressure is increased to 2MPa, 4MPa and rated working pressure in sequence. Under each pressure level, the blade is controlled to complete 3 full stroke synchronous actions. The allowable error of the relay stroke is ±0.5mm, the blade rotation angle synchronous deviation is ≤±0.05°, and the allowable deviation of the action time is ≤±15% of the design value.

[0113] S3.4. Limit stroke balance verification: drive all blades synchronously to the fully open and fully closed limit positions, and maintain pressure for 5 minutes. The allowable pressure drop of the internal operating oil circuit is ≤0.03MPa, the displacement change at the limit position is ≤0.2mm, and confirm that there is no off-center load interference.

[0114] The purpose of this design is that traditional methods using internal and external hydraulic pressure synchronization testing cannot isolate the imbalance problem of the internal control drive system. Defects such as asynchronous blade movement and jamming are masked, and these defects are the main causes of periodic alternating unbalanced forces during impeller operation. Therefore, using low pressure eliminates fundamental defects such as blade rotation jamming and mechanical interference, avoiding damage to the impeller during high-pressure testing. At the same time, it verifies the initial synchronization of all blade movements, discovers the time difference caused by uneven assembly clearance, simulates blade movement performance under different working pressures, detects the impact of pressure changes on blade movement synchronization, ensures that all blade movements are uniform and consistent across the full load range, and finally verifies the force balance of the blades at the fully open and fully closed limit positions to avoid impeller vibration caused by uneven load at the limit positions.

[0115] In its specific implementation, S4 includes the following sub-steps:

[0116] S4.1. Close the internal operating oil circuit, fix all blades of the runner body in the middle balance position, and introduce the rated test pressure of 6.3MPa into the runner oil pressure balance test system;

[0117] S4.2. Automatically maintain pressure for 60 minutes, record the pressure value every 10 minutes, and calculate the total pressure drop value of the impeller body seal balance. :

[0118] ;

[0119] in, To maintain the initial pressure, This is the pressure after holding the pressure for 60 minutes;

[0120] S4.3.If If the leakage is less than the set threshold and there is no visible leakage, the impeller body seal balance is deemed qualified.

[0121] The purpose of this design is to introduce rated pressure into the sealing cavity separately, eliminate interference from the internal operating drive system, and accurately detect the uniformity of the sealing pressure distribution of the impeller body; to verify the long-term balance and stability of the sealing system through long-term pressure holding tests, and to discover hidden defects such as no leakage in the early stage but uneven pressure distribution in the later stage; and to determine whether there is a unilateral force imbalance caused by local sealing failure by monitoring the change of blade rotation angle.

[0122] In its specific implementation, S5 includes the following sub-steps:

[0123] S5.1. Simultaneously supply rated working pressure to the internal and external operating oil circuits, control the pressure synchronization deviation between the two circuits to ≤0.05MPa, and simulate the oil pressure balance condition of the actual operation of the impeller.

[0124] S5.2. Control all blades to continuously and synchronously reciprocate 5 times within the full stroke range, with the internal and external hydraulic pressure response time difference ≤0.2s, the action speed fluctuation coefficient ≤0.15, and the pressure fluctuation value ≤0.1MPa;

[0125] S5.3. Fix the impeller blades in three balanced positions: fully open, fully closed, and intermediate, and maintain pressure for 15 minutes. Monitor the uniformity of pressure distribution throughout the process. After the pressure holding period, automatically generate a report indicating whether the balance performance is qualified or unqualified.

[0126] The purpose of this design is to address the potential imbalances in the operation of the internal and external operating systems when they are tested separately, such as pressure asynchrony and lack of coordination. These problems only become apparent under actual operating conditions. Therefore, the rated working pressure is simultaneously supplied to the internal and external operating oil circuits to accurately simulate the actual oil pressure environment of the rotor, test the synchronization and coordination of the two oil pressure circuits, and verify the smoothness of the blade's movement and pressure fluctuation characteristics during continuous operation through a full-stroke reciprocating motion test. Through multi-position pressure holding tests, the overall force balance of the blade under different opening degrees is detected to ensure that there is no off-center load phenomenon in all working positions.

[0127] In its specific implementation, S6 includes the following sub-steps:

[0128] S6.1. Reduce the internal operating oil circuit pressure to 0MPa at a rate of 0.1MPa / min to avoid the imbalance of the rotor force caused by instantaneous pressure relief;

[0129] S6.2. Reduce the external operating oil circuit pressure to 0 MPa at a rate of 0.15 MPa / min;

[0130] S6.3. Open the drain valve to drain the residual oil. When the oil level is ≤5mm, a message indicating that draining is complete will be issued.

[0131] S6.4. Automatically store all balance test data such as pressure, stroke, rotation angle, synchronization, vibration, etc.

[0132] The purpose of this design is to prevent displacement and force imbalance of the rotor components caused by instantaneous pressure shock through gradual pressure release in stages, thus protecting the assembly accuracy of the rotor; to automatically drain residual oil, preventing subsequent transportation and assembly problems caused by oil residue; and to automatically store all balance test data, generating traceable electronic reports to provide preliminary data references for subsequent whole-machine mechanical balance tests, while also meeting the requirements of subsequent management systems.

[0133] In this embodiment, a matching test method is also provided based on the test system. In addition to the hardware involved in the test system, an intelligent control system is also provided, including a Siemens S7-1200 PLC controller, an electric oil pump group, a 0.1-level pressure sensor, a ±0.1mm accuracy displacement sensor, a ±0.05° accuracy angle sensor, a ±0.01mm / s accuracy vibration sensor, and an audible and visual alarm module. The system sampling frequency is 10Hz.

[0134] A hydraulic balance test was conducted on the runner of a certain model of 100MW axial-flow propeller turbine. Its design parameters are: rated stroke of the servo motor 250mm, rated blade angle ±15°, and rated working pressure 6.3MPa. The purpose of the test was to verify the runner's synchronicity of movement under hydraulic drive, the uniformity of sealing pressure, and the overall force balance, and to identify assembly defects that might lead to dynamic imbalance during subsequent operation. The specific test steps are as follows:

[0135] S1. Before testing and system balance verification, select a transition flange 9 that matches the size of the inner core of the wheel to be tested, connect the inner cover 7 to the transition flange 9 with the connecting nut 6, and then fix the transition flange 9 to the inner core 17 of the wheel with the second bolt 10 to ensure that the coaxiality between the inner cover 7 and the inner core 17 of the wheel is ≤0.1mm.

[0136] Align the annular protrusion 18 of the outer cover 2 with the flange of the rotating wheel body, install the φ620mm first O-ring 1 on the side of the annular protrusion 18 facing the rotating wheel body, install the φ580mm second O-ring 5 on the inner ring, insert the first bolt 3 and the first gasket 4, and tighten them evenly in three times in a diagonal sequence to ensure uniform distribution of sealing pressure.

[0137] Install a cover plate 14 and a φ40mm fourth O-ring seal 12 at the bottom of the outer cover 2 cylinder and tighten them with the third bolt 13; pass the inner oil inlet core 15 through the cover plate 14 and thread it to the inner cover 7; install the third O-ring seal 11 on the connection surface between the inner cover 7 and the transition flange 9 to complete the assembly of the dual oil circuit balance test chamber.

[0138] according to Figure 2 The pipeline connection diagram shows the connection of the internal control oil inlet pipe, the external control oil inlet pipe, and the oil outlet pipe. The internal control oil inlet pipe is connected in series with one set of ball valve 101, one set of ball valve 102, and pressure gauge 1. The external control oil inlet pipe is connected in series with two sets of ball valve 201, two sets of ball valve 202, and pressure gauge 2. The oil outlet pipe is connected in series with the first ball valve. Check that all ball valves are in the closed state.

[0139] The PLC controller automatically calibrates the zero points of all pressure sensors, displacement sensors, angle sensors, and vibration sensors, confirms normal sensor communication, ensures no system faults during self-testing, and guarantees a balanced initial test state.

[0140] S2. Test system oil pressure balance pre-verification. The PLC controller sends an instruction to open the two sets of No. 1 ball valves 201 and No. 2 ball valves 202 of the external operator oil inlet pipeline, and close the one set of No. 1 ball valve 101, the one set of No. 2 ball valve 102 of the internal operator oil inlet pipeline and the first ball valve of the oil drain pipeline.

[0141] The electric oil pump is controlled to supply hydraulic oil to the oil pressure test chamber 16 at a constant rate of 0.2 MPa / min, and the pressure is increased sequentially to 0.5 MPa, 2 MPa, and 4 MPa, with each pressure level automatically held for 10 minutes. During the pressure holding period, an incremental PID algorithm is used for closed-loop control of oil pressure balance. =2.5, =0.15, =0.08, pressure fluctuation is stable within ±0.01MPa, and oil pressure distribution uniformity is ≥98%;

[0142] Continue increasing the pressure to the rated test pressure of 6.3 MPa, automatically maintain the pressure for 30 minutes, and the PLC calculates the balanced pressure drop value of the test system in real time.

[0143] ;

[0144] If the pressure drop is 0.02MPa≤0.05MPa and there is no visible leakage at the connection between the outer cover 2 and the wheel body, or at the connection between the cover plate 14, the oil pressure balance of the test system is deemed qualified, and the interference of the tooling imbalance on the test results can be eliminated.

[0145] S3. Internal operation oil circuit independent action balance test: keep the external operation oil inlet pipeline valve closed and the oil pressure test chamber 16 pressureless. The PLC controller sends a command to open a set of ball valve 101 and a set of ball valve 102 in the internal operation oil inlet pipeline.

[0146] Low-pressure no-load balancing break-in was performed by introducing 1.0MPa low-pressure oil into the inner core 17 of the impeller. All four blades were controlled to reciprocate synchronously three times within their full stroke range. The average single-stroke time for a single blade was 12s, with a maximum deviation of 4.2% ≤ ±10%. The maximum time difference between adjacent blades was 0.12s ≤ 0.2s. Displacement, angle, and vibration sensors collected data in real time. No motion jamming was detected. The minimum acceleration was 0.3m / s², and the maximum abnormal vibration amplitude was 0.2mm / s.

[0147] The graded load balancing test was conducted by sequentially increasing the pressure to 2MPa, 4MPa, and 6.3MPa. Under each pressure level, the control blades completed three full-stroke synchronous movements. The PLC automatically recorded the test data: the measured stroke of the relay was 250.2mm with an error of +0.2mm ≤ ±0.5mm; the measured rotation angle of each blade was +15.01° to -14.99°; the maximum synchronization deviation was 0.03° ≤ ±0.05°; and the maximum deviation in action time was 8.5% ≤ ±15%. All parameters met the balance requirements.

[0148] Limit stroke balance verification: PLC synchronously drives all blades to the fully open and fully closed limit positions, and automatically maintains pressure for 5 minutes each; the pressure drop values ​​of the internal operating oil circuit are 0.01MPa and 0.015MPa, respectively, both ≤0.03MPa; the displacement sensor detects that the displacement change of each blade at the limit position is ≤0.1mm, and there is no off-center load interference phenomenon.

[0149] S4. External operation oil circuit independent sealing balance test: The PLC controller closes a set of ball valve 101 and a set of ball valve 102 in the internal operation oil inlet pipeline, and fixes all blades in the middle balance position to avoid uneven force on the blades affecting the sealing balance test.

[0150] The rated test pressure of 6.3 MPa was introduced into the oil pressure test chamber 16 again, and the pressure was automatically maintained for 60 minutes. The pressure value was automatically recorded every 10 minutes. During the pressure maintenance period, the pressure was stable and there was no sudden drop. The pressure distribution at each sealing point was uniform.

[0151] After the pressure holding period ends, the PLC calculates the total pressure drop of the impeller body seal balance:

[0152] ;

[0153] The pressure drop is 0.02MPa≤0.03MPa, and the change in the rotation angle of all blades is ≤0.03° with no visible leakage. Therefore, the seal balance of the impeller body is deemed qualified, and there is no oil pressure imbalance caused by local seal failure.

[0154] S5. Combined internal and external control oil pressure balance test: The PLC controller simultaneously opens the valves of the internal control oil inlet pipe and the external control oil inlet pipe, and simultaneously introduces a rated working pressure of 6.3MPa into the two oil lines; synchronous closed-loop control is performed through dual pressure sensors, and the synchronous deviation of the two pressure lines is ≤0.03MPa, which accurately simulates the oil pressure balance condition of the actual operation of the impeller.

[0155] Control all blades to continuously and synchronously reciprocate 5 times within the full stroke range. The PLC collects and analyzes the balance data in real time: the response time difference between the internal and external hydraulic pressure is ≤0.15s, the action speed fluctuation coefficient Cv=0.12≤0.15, the pressure fluctuation value is ≤0.08MPa, and the action is smooth without off-center load.

[0156] The blades were fixed in three balanced positions: fully open, fully closed, and intermediate, and each position was automatically pressurized for 15 minutes. Pressure changes at all sealing points were monitored throughout the process. No leakage was observed, and the pressure distribution uniformity was ≥97%. After the pressurization was completed, the system automatically generated a test report on the oil pressure balance performance of the impeller, and the overall performance was deemed qualified.

[0157] S6. Intelligent graded pressure relief and balance data management: The PLC controller first slowly opens the pressure relief valve of the internal operating oil inlet pipeline, and reduces the pressure of the internal operating oil circuit to 0MPa at a rate of 0.1MPa / min, so as to avoid sudden changes in the force and imbalance of the rotor caused by instantaneous pressure relief.

[0158] Then slowly open the pressure relief valve of the external operating oil inlet line at a rate of 0.15 MPa / min to reduce the pressure in oil pressure test chamber 16 to 0 MPa;

[0159] Finally, the first ball valve of the drain pipe is automatically opened to drain the residual hydraulic oil inside the device and the impeller; when the level sensor detects that the oil level is ≤3mm, it issues a draining completion prompt signal;

[0160] Operators disassemble the tooling in sequence, clean the oil stains on the surface of each component, and store it for later use; the PLC automatically stores all the balance data of this test, such as pressure, stroke, angle, synchronization, vibration, etc.

[0161] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for testing the hydraulic pressure balance of a turbine runner, implemented based on a turbine runner hydraulic pressure balance testing system, characterized in that, The test method for detecting the operational balance of a turbine runner under hydraulic drive includes the following steps: S1. Pre-test preparation and system verification: complete the test pipeline connection and sensor calibration, and confirm that all valves are closed to ensure that the initial state of the rotor oil pressure balance test system is balanced. S2. Pre-verification of hydraulic pressure balance of the test system: Hydraulic oil is introduced into the hydraulic pressure balance test system of the impeller, and multi-stage pressure holding test is carried out using the graded pressure increase method. The hydraulic pressure balance and sealing performance of the impeller hydraulic pressure balance test system itself are determined based on the pressure drop value. S3. Independent operation balance test of internal operating oil circuit: Hydraulic oil is introduced into the internal operating oil circuit of the impeller separately, and low-pressure no-load balance break-in, graded load balance test and limit stroke balance verification are carried out in sequence. The synchronization and uniformity of blade movement are collected and analyzed. S4. Independent sealing balance test of external operating oil circuit: The rated test pressure is separately introduced into the runner oil pressure balance test system, and the sealing pressure balance performance of the runner body is determined through long-term pressure holding test, including the following sub-steps: S4.

1. Close the internal operating oil circuit, fix all blades of the runner body in the middle balance position, and introduce the rated test pressure into the runner oil pressure balance test system; S4.

2. Automatically maintain pressure for 60 minutes, record the pressure value every 10 minutes, and calculate the total pressure drop value of the impeller body seal balance. : ； in, To maintain the initial pressure, This is the pressure after holding the pressure for 60 minutes; S4.3.If If the leakage is less than the set threshold and there is no visible leakage, the impeller body seal balance is deemed qualified. S5. Comprehensive hydraulic balance test combining internal and external operation: Conduct full-stroke reciprocating motion balance test and multi-position pressure holding balance test to verify the overall hydraulic balance performance of the rotor, including the following sub-steps: S5.

1. Simultaneously supply rated working pressure to the internal and external operating oil circuits, control the synchronous deviation of the two pressures to be less than the set deviation threshold, and simulate the oil pressure balance condition of the actual operation of the impeller. S5.

2. Control all blades of the rotor to continuously and synchronously reciprocate throughout the entire stroke range; S5.

3. Fix the rotor blades in three balanced positions: fully open, fully closed, and in the middle, and maintain pressure for 15 minutes. Monitor the uniformity of pressure distribution throughout the process. After the pressure holding is completed, automatically generate a report on whether the balance performance is qualified or unqualified. S6. Intelligent graded pressure relief and balance data management: Depressurizes in stages according to preset rates, drains residual oil, automatically stores all balance test data and generates traceable electronic reports; The testing system includes an outer cover (2) and an inner cover (7). The outer cover (2) is detachably connected to the rotating body. One end of the inner cover (7) is connected to the inner core (17) of the rotating body. An oil pressure testing chamber (16) is provided inside the outer cover (2). A first oil inlet is provided on one side of the outer cover (2) and is connected to the oil pressure testing chamber (16). A first sealing connection structure is provided at the connection between the outer cover (2) and the rotating body. The inner cover (7) is located inside the oil pressure test chamber (16). The other end of the inner cover (7) is connected to the inner operating oil inlet core (15), and the inner operating oil inlet core (15) is connected to the inner core (17) of the rotor body.

2. The method for testing the hydraulic pressure balance of a turbine runner according to claim 1, characterized in that, S2 includes the following sub-steps: S2.

1. Open the external control oil inlet valve and close the internal control oil inlet and drain valves; S2.

2. The pressure is increased sequentially to 0.5MPa, 2MPa and 4MPa at a constant rate. The pressure is automatically maintained for 10 minutes at each pressure level. The pressure fluctuation during the pressure holding period is less than the set pressure fluctuation value to ensure uniform oil pressure distribution in the test system. S2.

3. Increase the pressure to the rated test pressure, maintain the pressure automatically for 30 minutes, and calculate the balanced pressure drop value of the test system. : ； in, To maintain the initial pressure, This is the pressure after holding the pressure for 30 minutes; like If the oil pressure is below the set threshold and there is no visible leakage, the oil pressure balance of the test system is deemed qualified.

3. The method for testing the hydraulic pressure balance of a turbine runner according to claim 1, characterized in that, S3 includes the following sub-steps: S3.

1. Keep the external operating oil circuit closed and open the internal operating oil inlet valve; S3.

2. Low-pressure no-load balance break-in: introduce low-pressure hydraulic oil and control all blades of the impeller to reciprocate synchronously within the full stroke range. The allowable deviation of the single blade action time is less than the set design value. S3.

3. Graded load balance test: the pressure is increased sequentially to 2MPa, 4MPa and rated working pressure, and the blades are controlled to complete the full stroke synchronous action under each pressure level; S3.

4. Limit stroke balance verification: drive all blades synchronously to the fully open and fully closed limit positions, and maintain pressure for 5 minutes. The allowable value of pressure drop in the internal operating oil circuit is less than the set allowable value, the displacement change at the limit position is less than the set limit displacement, and confirm that there is no off-center load interference.

4. The method for testing the hydraulic pressure balance of a turbine runner according to claim 1, characterized in that, The outer cover (2) is cylindrical, and the top of the outer cover (2) is provided with a circular protrusion (18), which is connected to the rotating body through the circular protrusion (18); The first sealing connection structure includes a first bolt (3), a first gasket (4), and a first O-ring (1); The first bolt (3) passes through the first washer (4), the annular protrusion (18), and the wheel body; The first O-ring seal (1) is located on the side of the annular protrusion (18) facing the wheel body, and the center of the first O-ring seal (1) overlaps with the center of the annular protrusion (18). The first O-ring seal (1) is closer to the center of the annular protrusion (18) than the first sealing connection structure. A second O-ring (5) is provided on the inner ring of the annular protrusion (18), and the second O-ring (5) is in contact with the part of the wheel body inserted into the inner ring of the annular protrusion (18).

5. The method for testing the hydraulic pressure balance of a turbine runner according to claim 4, characterized in that, The inner cover (7) is connected to a transition flange (9), and the transition flange (9) is connected to the inner core (17) of the wheel body; The transition flange (9) is connected to the inner core (17) of the rotor body by the second bolt (10), and the transition flange (9) is connected to the inner cover (7) by the connecting nut (6), and the connecting nut (6) is located between the center of the transition flange (9) and the second bolt (10).

6. The method for testing the hydraulic pressure balance of a turbine runner according to claim 5, characterized in that, The inner cover (7) is provided with a third O-ring (11), and the third O-ring (11) is located on the side of the inner cover (7) facing the transition flange (9), and the center of the third O-ring (11) coincides with the center line of the inner cover (7).

7. The method for testing the hydraulic pressure balance of a turbine runner according to claim 6, characterized in that, The bottom of the cylinder of the outer cover (2) is provided with a cover plate (14), and the inner oil inlet core (15) passes through the outer cover (2) and the cover plate (14). The cover plate (14) is detachably connected to the outer cover (2) by the third bolt (13). A fourth O-ring seal (12) is provided on the cover plate (14), and the fourth O-ring seal (12) is fitted around the outer periphery of the inner oil inlet core (15).

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