Complete machine collaborative verification experiment platform for flow and rotor dynamic characteristics of shielding type nuclear main pump

Abstract

The invention provides a shielding type nuclear main pump flow and rotor dynamic characteristic complete machine cooperation verification experiment platform which comprises a pump body, a rotating shaft, a stator shell, a power unit, a lubricating system and a measuring unit. Two ends of the rotating shaft are respectively mounted on the bracket through an upper supporting seat and a lower supporting seat; one end of the rotating shaft is connected with a flywheel in the pump body; a stator shell is arranged between the upper supporting seat and the lower supporting seat, and a gap exists between the rotating shaft and the stator shell; a lubricating medium in the lubricating system passes through the interior of the lower supporting seat, the gap and the interior of the upper supporting seat to form a closed-loop system; the torque and rotating speed sensor is used for measuring the torque and rotating speed of the rotating shaft; and a plurality of pressure sensor groups are arranged on the stator shell along the rotating shaft direction. Visual measurement of the pump head drainage basin and the shielding sleeve gap drainage basin can be achieved, the method can be used for researching the internal flow rule of the whole nuclear main pump, and the influence mechanism of the dynamic behavior of the rotating shaft on the whole machine flow field is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear main pump testing, and in particular to a whole-machine collaborative verification experimental platform for flow and rotor dynamics characteristics of a shielded nuclear main pump. Background Art

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

[0003] The cooling medium of the primary circuit of the shaft-sealed nuclear main pump is sealed inside the pump head, so that the design of the hydraulic components is mainly focused on the impeller with a relatively mature theoretical basis, avoiding complex rotor dynamics design. For the shielded nuclear main pump, through the pressure boundary conversion, the cooling medium of the primary circuit is introduced into the shielded motor, so that the incomplete pressure boundary becomes a complete pressure boundary, improving the sealing of the primary circuit and effectively preventing the leakage of radioactive media. However, this structure allows the cooling medium flowing inside the pump head to enter the shielded motor, causing the shielded motor gap flow problem, so that the design of the hydraulic components of the shielded nuclear main pump needs to pay attention not only to the impeller, but also to the rotor dynamics of the shielded motor.

[0004] The complex dynamic behavior of the whole flow of the shielded nuclear main pump and its relationship with the rotor plays an important role in the stability and safety of the rotor system. At present, the experimental research on the nuclear main pump mainly focuses on the design, manufacture and optimization of hydraulic components. There are relatively few studies on the flow characteristics of the whole machine and the dynamic characteristics of the rotor, and there are even fewer studies on the influence of the coupling between the pump head flow field and the shielded motor on the rotor system. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a shielded nuclear main pump flow and rotor dynamics characteristics collaborative verification experimental platform, which can realize the visual measurement of the pump head flow field and the shield sleeve gap flow field, and can be used to study the internal flow laws of the nuclear main pump as a whole, and obtain the influence mechanism of the dynamic behavior of the rotating shaft on the flow field of the whole machine.

[0006] The present invention achieves the above technical objectives through the following technical means.

[0007] A canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform, including a pump body, a rotating shaft, a stator housing, a power unit, a lubrication system and a measurement unit;

[0008] The two ends of the rotating shaft are respectively installed on the bracket through the upper support seat and the lower support seat, one end of the rotating shaft is connected to the flywheel in the pump body; the other end of the rotating shaft is connected to the power unit; a stator housing is provided between the upper support seat and the lower support seat, the rotating shaft passes through the stator housing, and there is a gap between the rotating shaft and the stator housing; the lubricating medium in the lubrication system passes through the interior of the lower support seat, the gap and the interior of the upper support seat, forming a closed-loop system;

[0009] The measuring unit comprises a pressure sensor group and a torque and speed sensor, wherein the torque and speed sensor is used to measure the torque and speed of the rotating shaft; a plurality of pressure sensor groups are arranged on the stator housing along the rotating shaft direction, which are used to measure the pressure distribution in the gap flow region.

[0010] Furthermore, the measuring unit also includes 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 to measure the axial trajectory of the rotating shaft in the upper support seat; the upper eddy current displacement sensor group is used to measure the axial trajectory of the rotating shaft in the lower support seat; the pump head pressure sensor group is used to measure the pressure pulsation in the pump head flow field.

[0011] Furthermore, the outer shell of the pump body and the stator shell are made of transparent materials.

[0012] Furthermore, the diameter ratio η of the stator housing is 0.01-0.02, where η=d i / d0,d i is the shaft diameter of the shaft section corresponding to the gap, and d0 is the inner diameter of the stator housing;

[0013] The aspect ratio Γ of the stator housing is 3-5, wherein Γ=L / d, L is the length of the stator housing; d is the width of the gap.

[0014] Furthermore, by replacing stator casings with different diameter ratios and / or aspect ratios, the effects of different stator casing gaps on the rotor dynamic characteristics are studied.

[0015] Furthermore, the pump head pressure sensor group is evenly distributed on a pitch circle with the rotating shaft as the center, and the diameter of the pitch circle is d p It is 1.1 to 1.3 times the diameter of the guide vane outlet in the pump body.

[0016] Furthermore, the pressure sensor located at the top of the stator housing and the upper eddy current displacement sensor group are located in the same radial section; the pressure sensor located at the bottom of the stator housing and the lower eddy current displacement sensor group are located in the same radial section.

[0017] Furthermore, the upper eddy current displacement sensor group and the lower eddy current displacement sensor group each have two sensors as a group, and the two sensors in the same group are arranged perpendicular to each other.

[0018] The beneficial effects of the present invention are:

[0019] 1. The shielded nuclear main pump flow and rotor dynamics characteristics collaborative verification experimental platform described in the present invention can realize the visual measurement of the pump head flow field and the stator casing gap flow field, and can be used to study the internal flow law of the nuclear main pump as a whole machine and obtain the influence mechanism of the dynamic behavior of the rotating shaft on the flow field of the whole machine.

[0020] 2. The shielded nuclear main pump flow and rotor dynamics characteristics collaborative verification experimental platform described in the present invention can measure the axis trajectory of the shaft in real time through eddy current displacement sensors arranged near the upper and lower guide bearings, so as to study the rotor dynamics characteristics of the shielded nuclear main pump.

[0021] 3. The shielded nuclear main pump flow and rotor dynamics characteristics collaborative verification experimental platform described in the present invention can measure the torque exerted on the shaft in real time through the torque and speed sensor, and can accurately and effectively monitor the fluid force exerted on the shaft during operation.

[0022] 4. The shielded nuclear main pump flow and rotor dynamics characteristics collaborative verification experimental platform described in the present invention can obtain gaps with different diameter ratios, aspect ratios and eccentricities by replacing stator casings with different inner wall structures, so as to study the influence of different stator casing gap flow structures on the rotor dynamics characteristics.

[0023] 5. The shielded nuclear main pump flow and rotor dynamics characteristics collaborative verification experimental platform described in the present invention has a large number of pressure sensors installed in the axial direction of the stator housing, which can realize real-time monitoring of the gap flow field changes, help to restore the pressure distribution of the entire flow field and the vibration state of the shaft, and can be mutually verified with the data of the eddy current displacement sensor, making the experimental results more reliable.

[0024] 6. The shielded nuclear main pump flow and rotor dynamics characteristics collaborative verification experimental platform described in the present invention can realize the hydraulic performance test of the nuclear main pump by connecting to an external circuit, and study its hydraulic characteristics by replacing different hydraulic components, thereby completing the optimization design of the nuclear main pump hydraulic model.

[0025] 7. The shielded nuclear main pump flow and rotor dynamics characteristics collaborative verification experimental platform described in the present invention has a pressure sensor installed on the pump casing, which can obtain pressure pulsation information at the measuring point to explore methods for suppressing vibration and noise of the nuclear main pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings described below are some embodiments of the present invention. For ordinary technicians in this field, it is obvious that other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 Schematic diagram of the whole-machine collaborative verification experimental platform for the flow and rotor dynamics characteristics of the shielded nuclear main pump described in the present invention.

[0028] Figure 2 The exploded view of the pump body assembly of the present invention.

[0029] Figure 3 This is an exploded view of the measuring unit on the stator housing according to the present invention.

[0030] Figure 4 This is a schematic diagram of the distribution of monitoring points of the pressure sensor on the pump casing of the present invention.

[0031] Figure 5 It is a schematic diagram of the positional relationship between the stator housing and the rotating shaft according to the present invention.

[0032] Figure 6 The experimental flow chart of the test platform of the present invention.

[0033] In the figure:

[0034] 1- pump casing; 2- impeller; 3- guide vane; 4- upper flywheel; 5- upper guide bearing; 6- upper eddy current displacement sensor group; 7- stator casing; 8- shaft; 9- lower eddy current displacement sensor group; 10- lower guide bearing; 11- lower flywheel; 12- thrust bearing; 13- upper coupling; 14- torque 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 meter support frame; 28- motor support frame. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] like Figure 1 and Figure 2 As shown, the canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform of the present invention comprises a pump body, a rotating shaft 8, a stator housing 7, a power unit, a lubrication system and a measuring unit;

[0039] The pump body includes a pump casing 1, an impeller 2 and a guide vane 3, wherein the impeller 2 is connected to one end of a rotating shaft 8, and the impeller 2, the pump casing 1 and the guide vane 3 form a pump head, which 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 is ground against a thrust bearing 12;

[0040] The two ends of the rotating shaft 8 are respectively installed on the bracket through the upper support seat and the lower support seat, specifically: the upper guide bearing 5 is assembled on the upper bearing support frame 21, and the lower guide bearing 10 and the thrust bearing 12 are assembled on the lower bearing support frame 25, so as to realize the axial support and radial support of the shaft, and the bearing lubricating medium is water; the motor 16 is installed below the motor support frame 28, and the other end of the rotating shaft 8 is connected to the motor 16; a stator housing 7 is provided between the upper support seat and the lower support seat, the rotating shaft 8 passes through the stator housing 7, and there is a gap between the rotating shaft 8 and the stator housing 7; the lubricating medium in the lubrication system passes through the interior of the lower support seat, the gap and the interior of the upper support seat, so as to form a closed-loop system;

[0041] like Figure 3 and Figure 4 As shown, the measuring unit includes a pressure sensor group 22 and a torque and speed sensor 14, and the torque and speed sensor 14 is used to measure 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 its upper end is connected to the rotating shaft 8 through the upper coupling 13; the motor 16 is connected to the lower end of the torque and speed sensor 14 through the lower coupling 15. The upper coupling 13 and the lower coupling 15 are elastic couplings (such as plum blossom couplings) with relatively small interference with the movement of the rotating shaft 8, which can compensate for the relative displacement of the two shafts, absorb vibration and mitigate impact. A plurality of pressure sensor groups 22 are arranged axially on the stator housing 7 to measure the pressure distribution of the gap flow field. The number of sensors in the pressure sensor group 22 is 3 to 5. Too few sensors will obtain insufficient pressure field resolution, and too many sensors will destroy the flow structure of the gap flow field.

[0042] The measuring unit also includes an upper eddy current displacement sensor group 6, a lower eddy current displacement sensor group 9 and a pump head pressure sensor group 17; the upper eddy current displacement sensor group 6 is used to measure the axial trajectory of the rotating shaft 8 in the upper support seat; the upper eddy current displacement sensor group 9 is used to measure the axial trajectory of the rotating shaft 8 in the lower support seat; the pump head pressure sensor group 17 is used to measure the pressure pulsation in the pump head flow field.

[0043] The pump housing 1 and the stator housing 7 are both square outside and round inside, and are made of organic glass to avoid optical distortion during flow visualization measurement.

[0044] The stator housing 7 can obtain different diameter ratios, aspect ratios and eccentric gaps 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 housing 7 is 0.01-0.02, where η=d i / d0,d iis the shaft diameter of the shaft section corresponding to the gap, d0 is the inner diameter of the stator housing; the aspect ratio Г of the stator housing 7 is 3-5, where Г=L / d, L is the length of the stator housing 7; d is the width of the gap. If there is eccentricity between the stator housing 7 and the rotating shaft 8, then d takes the minimum value, that is, the minimum width between the stator housing 7 and the rotating shaft 8, such as Figure 5 shown.

[0045] like Figure 4 As shown, the number of sensors in the pump head pressure sensor group 17 is 4 to 8, and the pump head pressure sensor group 17 is evenly distributed on a pitch circle with the rotating shaft 8 as the center, and the diameter of the pitch circle is d p It is 1.1 to 1.3 times the outlet diameter of the guide vane in the pump body. The pressure sensor located at the top of the stator housing 7 and the upper eddy current displacement sensor group 6 are located in the same radial section; the pressure sensor located at the bottom of the stator housing 7 and the lower eddy current displacement sensor group 9 are located in the same radial section. The upper eddy current displacement sensor group 6 and the lower eddy current displacement sensor group 9 are each composed of two sensors as a group, and the two sensors in the same group are arranged perpendicular to each other to obtain the axial displacement trajectory of the rotating shaft 8.

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

[0047] Assemble the vertical shielded nuclear main pump test body to ensure that the dynamic and static clearance (mouth ring clearance) between the impeller and the pump casing and the clearance between the stator casing 7 and the rotating shaft 8 have a size error within 0.01mm;

[0048] Install measuring instruments and configure 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 speed to the target speed value, and adjust the pump head circuit flow 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] The mutual verification analysis of the pump head flow field pressure data P1 and the shaft displacement data D1 under working condition I is carried out, and the consistency judgment index I DP The calculation formula is as follows:

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

[0054] Among them, α is the weight factor, 0.5≤α≤0.7; ρ is the difference sequence correlation coefficient; RMSE DP RMSE is the root mean square error of the difference sequence; max is the maximum value of the root mean square error of the difference sequence;

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

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

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

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

[0059] The shield sleeve gap flow field data P2 and the shaft displacement data D2 are mutually verified and analyzed under working condition II, and the analysis method is the same as above.

[0060] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0061] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform, characterized in that: It comprises a pump body, a rotating shaft (8), a stator housing (7), a power unit, a lubrication system and a measuring unit; The two ends of the rotating shaft (8) are respectively mounted on the bracket through an upper support seat and a lower support seat, one end of the rotating shaft (8) is connected to the flywheel (2) in the pump body; the other end of the rotating shaft (8) is connected to the power unit; a stator housing (7) is provided between the upper support seat and the lower support seat, the rotating shaft (8) passes through the stator housing (7), and a gap exists between the rotating shaft (8) and the stator housing (7); the lubricating medium in the lubrication system passes through the interior of the lower support seat, the gap and the interior of the upper support seat, forming a closed loop system; The measuring unit comprises a pressure sensor group (22) and a torque and speed sensor (14), wherein the torque and speed sensor (14) is used to measure the torque and speed of the rotating shaft (8); and a plurality of pressure sensor groups (22) are arranged along the axial direction on the stator housing (7) to measure the pressure distribution in the gap flow region.

2. The canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform according to claim 1 is characterized in that: The measuring unit further comprises an upper eddy current displacement sensor group (6), a lower eddy current displacement sensor group (9) and a pump head pressure sensor group (17); the upper eddy current displacement sensor group (6) is used to measure the axis center trajectory of the rotating shaft (8) in the upper support seat; the upper eddy current displacement sensor group (9) is used to measure the axis center trajectory of the rotating shaft (8) in the lower support seat; and the pump head pressure sensor group (17) is used to measure the pressure pulsation in the pump head flow field.

3. The canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform according to claim 1 is characterized in that: The pump body shell and the stator shell (7) are made of transparent materials.

4. The canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform according to claim 1 is characterized in that: 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 shaft section corresponding to the gap, and d0 is the inner diameter of the stator housing; The aspect ratio Γ of the stator housing (7) is 3-5, wherein Γ=L / d, L is the length of the stator housing (7); and d is the width of the gap.

5. The canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform according to claim 4 is characterized in that: By replacing a stator housing (7) with different diameter ratios and / or length-to-diameter ratios, the influence of different stator housing (7) gaps on the rotor dynamics characteristics is studied.

6. The canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform according to claim 1 is characterized in that: The pump head pressure sensor group 17 is evenly distributed on a pitch circle with the rotating shaft (8) as the center, and the diameter d of the pitch circle is p It is 1.1 to 1.3 times the diameter of the guide vane outlet in the pump body.

7. The canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform according to claim 2 is characterized in that: The pressure sensor located at the top of the stator housing (7) and the upper eddy current displacement sensor group (6) are located in the same radial section; the pressure sensor located at the bottom of the stator housing (7) and the lower eddy current displacement sensor group (9) are located in the same radial section.

8. The canned nuclear main pump flow and rotor dynamics characteristics whole machine collaborative verification experimental platform according to claim 2 is characterized in that: The upper eddy current displacement sensor group (6) and the lower eddy current displacement sensor group (9) each consist of two sensors as a group, and the two sensors in the same group are arranged perpendicular to each other.

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