A shielding type nuclear main pump flow and rotor dynamics characteristic whole machine cooperative verification experiment platform

Abstract

The application provides a shielding nuclear main pump flow and rotor dynamics characteristic whole machine cooperative verification experiment platform, which comprises a pump body, a rotating shaft, a stator shell, a power unit, a lubricating system and a measuring unit; the rotating shaft is installed on a support through upper and lower support seats at both ends, and one end of the rotating shaft is connected with a flywheel in the pump body; the upper and lower support seats are provided with the stator shell, and a gap exists between the rotating shaft and the stator shell; the lubricating medium in the lubricating system passes through the inside of the lower support seat, the gap and the inside of the upper support seat to form a closed loop system; the torque and speed sensor is used for measuring the torque and speed of the rotating shaft; a plurality of pressure sensor groups are arranged on the stator shell along the rotating shaft. The application can realize visual measurement of the pump head flow field and the shielding sleeve gap flow field, and can be used for studying the internal flow law of the nuclear main pump whole machine, and obtaining the influence mechanism of the dynamics behavior of the rotating shaft on the whole machine flow field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear main pump testing, and particularly relates to a shielded nuclear main pump flow and rotor dynamics characteristic whole machine cooperative verification experiment platform. BACKGROUND

[0002] The nuclear reactor coolant main circulation pump, referred to as a nuclear main pump, is one of the key equipment of a pressurized water reactor nuclear power plant, and is located between a reactor and a steam generator in a primary loop of the nuclear power plant. In the normal operation process of the nuclear reactor, the nuclear main pump drives the circulation of the coolant in the primary loop of the nuclear power plant, thereby realizing heat transfer. As the only rotating equipment in the primary loop system, the reliability of the nuclear main pump is directly related to the safety of the nuclear power plant.

[0003] For the shaft seal type nuclear main pump, the primary loop cooling medium is sealed in the pump head, so that the design of the hydraulic components is mainly concentrated on the impeller which has a relatively mature theoretical basis, and the complex rotor dynamics design is avoided. For the shielded nuclear main pump, the primary loop cooling medium is introduced into the shielded motor through pressure boundary conversion, so that the non-complete pressure boundary becomes a complete pressure boundary, the sealing of the primary loop is improved, and the leakage of the radioactive medium is effectively prevented. However, this structure causes the cooling medium flowing in the pump head to enter the shielded motor, which brings the shielded motor gap flow problem, so that the design of the hydraulic components of the shielded nuclear main pump needs to not only pay attention to the impeller, but also pay attention to the rotor dynamics problem of the shielded motor.

[0004] The complex dynamics behavior between the whole machine flow of the shielded nuclear main pump and the rotor has an important role in the stability and safety of the rotor system. At present, the experimental research on the nuclear main pump is mainly concentrated on the design, manufacture and optimization of the hydraulic components, and the research on the whole machine flow characteristics and the rotor dynamics characteristics is relatively less, and there is almost no research on the influence of the coupling effect of the pump head flow field and the shielded motor gap on the rotor system. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a shielded nuclear main pump flow and rotor dynamics characteristic whole machine cooperative verification experiment platform, which can realize visual measurement of the pump head flow field and the shielded sleeve gap flow field, and can be used for researching the internal flow law of the whole machine of the nuclear main pump and obtaining the influence mechanism of the dynamics behavior of the rotating shaft on the whole machine flow field.

[0006] The present application achieves the above technical purpose through the following technical means.

[0007] The shielded nuclear main pump flow and rotor dynamics characteristic whole machine cooperative verification experiment platform comprises a pump body, a rotating shaft, a stator shell, a power unit, a lubrication system and a measurement unit.

[0008] The rotating shaft is installed on the support through the upper support seat and the lower support seat at both ends, one end of the rotating shaft is connected with the flywheel in the pump body, and the other end of the rotating shaft is connected with the power unit; the stator shell is arranged between the upper support seat and the lower support seat, the rotating shaft passes through the stator shell, and a gap exists between the rotating shaft and the stator shell; the lubricating medium in the lubricating system passes through the inside of the lower support seat, the gap and the inside of the upper support seat, and forms a closed loop system.

[0009] The measuring unit comprises a pressure sensor group and a torque and rotating speed sensor, the torque and rotating speed sensor is used for measuring the torque and rotating speed of the rotating shaft; a plurality of pressure sensor groups are arranged on the stator shell along the rotating shaft, and are used for measuring the pressure distribution of the gap flow area.

[0010] Further, the measuring unit further comprises an upper eddy current displacement sensor group, a lower eddy current displacement sensor group and a pump head pressure sensor group; the upper eddy current displacement sensor group is used for measuring the axial trajectory of the rotating shaft in the upper support seat; the lower eddy current displacement sensor group is used for measuring the axial trajectory of the rotating shaft in the lower support seat; and the pump head pressure sensor group is used for measuring the pressure pulsation of the pump head flow area.

[0011] Further, the shell of the pump body and the stator shell are made of transparent material.

[0012] Further, the diameter ratio η of the stator shell is 0.01-0.02, wherein η=d i / d0, d i is the shaft diameter of the gap corresponding to the rotating shaft section, and d0 is the inner diameter of the stator shell;

[0013] The length-diameter ratio Г of the stator shell is 3-5, wherein Г=L / d, L is the length of the stator shell, and d is the width of the gap.

[0014] Further, by replacing the stator shell with different diameter ratios and / or length-diameter ratios, the influence of different stator shell gaps on the dynamic characteristics of the rotor can be studied.

[0015] Further, the pump head pressure sensor groups are uniformly distributed on a graduated circle with the rotating shaft as the center, and the diameter d p of the graduated circle is 1.1-1.3 times the diameter of the guide vane outlet in the pump body.

[0016] Further, the pressure sensor located at the uppermost of the stator shell and the upper eddy current displacement sensor group are located in the same radial section; and the pressure sensor located at the lowermost of the stator shell and the lower eddy current displacement sensor group are located in the same radial section.

[0017] Further, the upper eddy current displacement sensor group and the lower eddy current displacement sensor group each comprise two sensors as a group, and the two sensors in the same group are arranged perpendicularly.

[0018] The present application has the advantages of:

[0019] 1. The shielding nuclear main pump flow and rotor dynamics characteristic whole machine collaborative verification experimental platform can realize visual measurement of the pump head flow field and the stator shell gap flow field, can be used for studying the internal flow law of the nuclear main pump whole machine, and can obtain the influence mechanism of the dynamic behavior of the rotating shaft on the whole machine flow field.

[0020] 2. The shielding nuclear main pump flow and rotor dynamics characteristic whole machine collaborative verification experimental platform can measure the shaft center trajectory in real time through the eddy current displacement sensor arranged near the upper and lower guide bearings, and can be used for studying the rotor dynamics characteristics of the shielding nuclear main pump.

[0021] 3. The shielding nuclear main pump flow and rotor dynamics characteristic whole machine collaborative verification experimental platform can measure the torque borne by the rotating shaft in real time through the torque and speed sensor, and can accurately and effectively monitor the fluid force borne by the rotating shaft during operation.

[0022] 4. The shielding nuclear main pump flow and rotor dynamics characteristic whole machine collaborative verification experimental platform can obtain different gap diameters, length-diameter ratios and eccentricities by replacing the stator shells with different inner wall structures, and can be used for studying the influence of different stator shell gap flow structures on the rotor dynamics characteristics.

[0023] 5. The shielding nuclear main pump flow and rotor dynamics characteristic whole machine collaborative verification experimental platform is provided with a plurality of pressure sensors installed in the axial direction of the stator shell, can realize real-time monitoring of the change of the gap flow field, is helpful for restoring the pressure distribution of the whole flow field and the vibration state of the rotating shaft, can be mutually verified with the data of the eddy current displacement sensor, and can make the experimental results have higher reliability.

[0024] 6. The shielding nuclear main pump flow and rotor dynamics characteristic whole machine collaborative verification experimental platform can realize nuclear main pump hydraulic performance test through connection of an external loop, can study the hydraulic characteristics by replacing different hydraulic components, and can complete the optimization design of the nuclear main pump hydraulic model.

[0025] 7. The shielding nuclear main pump flow and rotor dynamics characteristic whole machine collaborative verification experimental platform is provided with pressure sensors installed on the pump shell, can obtain the pressure fluctuation information at the measurement points, and can be used for exploring the vibration and noise suppression method of the nuclear main pump. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. The drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0027] Figure 1 The schematic diagram of the whole machine cooperative verification experiment platform for the flow and rotor dynamics characteristics of the shielding type nuclear main pump.

[0028] Figure 2 The blasting diagram of the pump body assembly.

[0029] Figure 3 The blasting diagram of the measurement unit on the stator shell.

[0030] Figure 4 The schematic diagram of the distribution of the monitoring points of the pressure sensor on the pump shell.

[0031] Figure 5 The schematic diagram of the positional relationship between the stator shell and the rotating shaft.

[0032] Figure 6 The experimental flowchart of the experimental platform of the present application.

[0033] In the drawings:

[0034] 1-pump shell; 2-impeller; 3-vane; 4-upper flywheel; 5-upper guide bearing; 6-upper eddy current displacement sensor group; 7-stator shell; 8-rotating shaft; 9-lower eddy current displacement sensor group; 10-lower guide bearing; 11-lower flywheel; 12-thrust bearing; 13-upper coupling; 14-torque and speed sensor; 15-lower coupling; 16-motor; 17-pump head pressure sensor group; 18-upper mechanical seal; 19-flywheel chamber; 20-water outlet; 21-upper bearing support frame; 22-pressure sensor group; 23-pump head support frame; 24-water inlet; 25-lower bearing support frame; 26-lower mechanical seal; 27-torque instrument support frame; 28-motor support frame. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0036] In the description of the present application, it is to be understood by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0037] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] As shown in Figure 1 and Figure 2 The shielding nuclear main pump flow and rotor dynamics characteristic integrated cooperative verification experiment platform of the present application comprises a pump body, a rotating shaft 8, a stator shell 7, a power unit, a lubrication system and a measurement unit;

[0039] The pump body comprises a pump shell 1, an impeller 2 and a guide vane 3, the impeller 2 is connected with one end of the rotating shaft 8, the impeller 2, the pump shell 1 and the guide vane 3 form a pump head, and the pump head is installed above a flywheel chamber 19; an upper flywheel 4 is assembled with the rotating shaft 8 and placed in the flywheel chamber 19; a lower flywheel 11 is assembled with the rotating shaft 8 and abuts against a thrust bearing 12;

[0040] The rotating shaft 8 is installed on the support through the upper support seat and the lower support seat at both ends, specifically, the upper guide bearing 5 is assembled on the upper bearing support frame 21, the lower guide bearing 10 and the thrust bearing 12 are assembled on the lower bearing support frame 25, the axial support and the radial support of the shaft are realized, and the bearing lubricating medium is water; the motor 16 is installed below the motor support frame 28, the other end of the rotating shaft 8 is connected with the motor 16; the stator shell 7 is arranged between the upper support seat and the lower support seat, the rotating shaft 8 passes through the stator shell 7, and there is a gap between the rotating shaft 8 and the stator shell 7; the lubricating medium in the lubricating system passes through the inside of the lower support seat, the gap and the inside of the upper support seat, and a closed loop system is formed.

[0041] As shown in Figure 3 and Figure 4 , the measuring unit includes the pressure sensor group 22 and the torque and speed sensor 14 for measuring the torque and speed of the rotating shaft 8; the torque and speed sensor 14 is installed on the torque meter support frame 27, and the upper end is connected with the rotating shaft 8 through the upper coupling 13; the motor 16 is connected with the lower end of the torque and speed sensor 14 through the lower coupling 15. The upper coupling 13 and the lower coupling 15 select the elastic coupling (such as the plum blossom coupling) which has relatively small interference to the movement of the rotating shaft 8, can compensate the relative displacement of the two shafts, and can absorb vibration and moderate impact. A plurality of pressure sensor groups 22 are arranged on the stator shell 7 in the axial direction, for measuring the pressure distribution of the gap flow field. The number of sensors of the pressure sensor group 22 is 3-5, too few sensors cannot obtain sufficient pressure field resolution, and too many sensors will destroy the flow structure of the gap flow field.

[0042] The measuring unit further includes the upper eddy current displacement sensor group 6, the lower eddy current displacement sensor group 9 and the pump head pressure sensor group 17; the upper eddy current displacement sensor group 6 is used for measuring the shaft center track of the rotating shaft 8 in the upper support seat; the lower eddy current displacement sensor group 9 is used for measuring the shaft center track of the rotating shaft 8 in the lower support seat; and the pump head pressure sensor group 17 is used for measuring the pressure pulsation of the pump head flow field.

[0043] The pump shell 1 and the stator shell 7 are both structures of outer square and inner circle, and the material is organic glass, so that optical distortion does not occur during flow visualization measurement.

[0044] The stator shell 7 can obtain different gap flow structures by replacing different inner wall structures, so as to study the influence of different gap flow structures on the dynamic characteristics of the rotating shaft 8. The diameter ratio η of the stator shell 7 is 0.01-0.02, wherein η=d i / d0, d iThe gap corresponds to the shaft section of the shaft diameter, d0 is the inner diameter of the stator shell; the length-diameter ratio of the stator shell 7 is 3-5, where G=L / d, L is the length of the stator shell 7; d is the width of the gap. If the stator shell 7 and the rotating shaft 8 are eccentric, then d takes the minimum value, that is, the minimum width between the stator shell 7 and the rotating shaft 8, as shown in Figure 5 .

[0045] As shown in Figure 4 , the number of sensors of the pump head pressure sensor group 17 is 4-8, and the pump head pressure sensor group 17 is uniformly distributed on the index circle with the rotating shaft 8 as the center, and the diameter d p of the index circle is 1.1-1.3 times the diameter of the pump body inner vane outlet. The pressure sensor located at the uppermost of the stator shell 7 is located in the same radial section as the upper eddy current displacement sensor group 6; the pressure sensor located at the lowermost of the stator shell 7 is located in the same radial section as the lower eddy current displacement sensor group 9. The upper eddy current displacement sensor group 6 and the lower eddy current displacement sensor group 9 are both in a group of two sensors, and the two sensors in the same group are arranged perpendicular to each other, so as to obtain the shaft center displacement trajectory of the rotating shaft 8.

[0046] As shown in Figure 6 , the experimental method of the experimental platform includes the following steps:

[0047] Assemble the vertical shielded nuclear main pump test body, and ensure that the size error of the dynamic static gap (ring gap) between the impeller and the pump shell and the size error of the gap between the stator shell 7 and the rotating shaft 8 are within 0.01 mm;

[0048] Install the measuring instruments and configure the data acquisition system;

[0049] Ensure that the inlet and outlet valves of the pump head circuit are fully open, and the inlet and outlet valves of the lubrication system are fully closed;

[0050] Start the motor, adjust the rotating speed to the target rotating speed value, and adjust the flow of the pump head circuit to the target flow value (working condition I);

[0051] Collect the flow field pressure data P1 of the pump head pressure sensor group and the displacement data D1 of the upper and lower eddy current displacement sensor groups under working condition I;

[0052] Perform mutual verification analysis of the pump head flow field pressure data P1 and the shaft displacement data D1 under working condition I, and the consistency judgment index I DP of the two is calculated as follows:

[0053] I DP = αR + (1-α)(1-RMSE DP / RMSE max )

[0054] Wherein, a is a weight factor, 0.5≤a≤0.7; p is a difference sequence correlation coefficient; RMSE DP is a difference sequence root mean square error; RMSE max is a maximum value of the difference sequence root mean square error;

[0055] If the consistency judgment index I DP ≤0.9, it is considered that the data is effective to a certain extent, otherwise the installation accuracy of each sensor needs to be adjusted;

[0056] Ensure that the pump head circuit inlet and outlet valves and the shield sleeve circuit inlet and outlet valves are fully open;

[0057] Keep the rotating speed unchanged, and adjust the shield sleeve circuit flow to the target flow value (working condition II);

[0058] Collect the flow field pressure data P2 of the shield sleeve pressure sensor group and the displacement data D2 of the upper and lower eddy current displacement sensor groups in working condition II;

[0059] Perform mutual verification analysis of the shield sleeve gap flow field data P2 and the shaft displacement data D2 in working condition II, and the analysis method is the same as above.

[0060] It should be understood that although the present specification is described in terms of various embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity. The skilled person should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by the skilled person.

[0061] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present application, and are not intended to limit the protection scope of the present application. Any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A shielded nuclear main pump flow and rotor dynamics characteristics overall system collaborative verification experiment platform, characterized in that, The pump body, the rotating shaft (8), the stator shell (7), the power unit, the lubricating system and the measuring unit are included. The rotating shaft (8) is installed on the support through the upper support seat and the lower support seat at both ends, and the rotating shaft (8) is connected with the flywheel (2) in the pump body at one end; the rotating shaft (8) is connected with the power unit at the other end; the stator shell (7) is arranged between the upper support seat and the lower support seat, the rotating shaft (8) passes through the stator shell (7), and a gap exists between the rotating shaft (8) and the stator shell (7); the lubricating medium in the lubricating system passes through the inside of the lower support seat, the gap and the inside of the upper support seat, and forms a closed loop system. The measuring unit includes the pressure sensor group (22), the torque and speed sensor (14), the upper eddy current displacement sensor group (6), the lower eddy current displacement sensor group (9) and the pump head pressure sensor group (17), the torque and speed sensor (14) is used for measuring the torque and speed of the rotating shaft (8); a plurality of pressure sensor groups (22) are arranged on the stator shell (7) in the axial direction, and are used for measuring the pressure distribution of the gap flow field; The upper eddy current displacement sensor group (6) is used for measuring the shaft center track of the rotating shaft (8) in the upper support seat; the lower eddy current displacement sensor group (9) is used for measuring the shaft center track of the rotating shaft (8) in the lower support seat; and the pump head pressure sensor group (17) is used for measuring the pressure pulsation of the pump head flow field.

2. The experimental platform of claim 1, wherein, The shell of the pump body and the stator shell (7) are transparent materials.

3. The experimental platform of claim 1, wherein, The diameter ratio η of the stator housing (7) is 0.01-0.02, where η=d i / d0, d i is the shaft diameter of the gap corresponding shaft section, and d0 is the inner diameter of the stator housing. The length-diameter ratio G of the stator shell (7) is 3-5, wherein G=L / d, L is the length of the stator shell (7), and d is the width of the gap.

4. The experimental platform of claim 3, wherein, By replacing the stator shell (7) with different diameter ratios and / or length-diameter ratios, the influence of the gap of different stator shells (7) on the rotor dynamics characteristics is studied.

5. The integrated experimental platform for flow and rotor dynamics characteristics of a shielded nuclear primary pump according to claim 1, wherein, The pump head pressure sensor groups (17) are uniformly distributed on a circle with the rotating shaft (8) as the center, and the diameter d of the circle is 0.8~1.2 times the diameter of the rotating shaft (8) p The diameter of the inner guide vane outlet is 1.1~1.3 times the diameter of the pump body.

6. The integrated flow and rotor dynamics platform of claim 1, wherein, The pressure sensor located at the uppermost of the stator shell (7) is located in the same radial section as the upper eddy current displacement sensor group (6); and the pressure sensor located at the lowermost of the stator shell (7) is located in the same radial section as the lower eddy current displacement sensor group (9).

7. The integrated experimental platform for flow and rotor dynamics characteristics of a shielded nuclear primary pump according to claim 1, wherein, The upper eddy current displacement sensor group (6) and the lower eddy current displacement sensor group (9) are each a group of two sensors, and the two sensors in the same group are arranged perpendicularly.

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