Performance test method of liquid metal lead bismuth pump

Abstract

The invention discloses a performance test method of a liquid metal lead bismuth pump, which comprises the following steps of: 1) dividing a lead bismuth pump flow channel into a plurality of coaxial cylindrical flow surfaces, and unfolding the cylindrical surfaces into planes along the generatrix of the cylindrical surfaces to obtain plane blade grids of blades of an impeller on the cylindrical surfaces; (2) fluid data are obtained, and the lift H of the lead-bismuth pump is calculated; 3) calculating a pressure difference P between an inlet and an outlet of the runner; and 4) calculating the maximum flow velocity vmax and the hydraulic efficiency eta of the lead-bismuth pump. According to the test method, the maximum flow velocity and the hydraulic performance of the lead-bismuth pump are accurately tested, and the performance of the lead-bismuth pump is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of lead-bismuth pump performance testing, and in particular to a performance testing method for a liquid metal lead-bismuth pump. Background Art

[0002] The fourth generation nuclear reactor technology has good safety, reliability, stability and sustainability. Lead / lead-bismuth coolants are considered to be the earliest to be used in commercial fourth generation reactors due to their stable chemical properties, strong thermal conductivity and good processing capabilities for spent fuel conversion. The fourth generation nuclear reactors include sodium-cooled fast reactors (SFRs), lead-cooled fast reactors (LFRs), molten salt reactors (MSRs), supercritical water-cooled reactors (SCWRs), gas-cooled fast reactors (GFRs) and very high temperature gas-cooled reactors (VHTRs). Among them, the lead-bismuth reactor has significant advantages such as inherent safety, easy miniaturization and good sustainability, and is an important research direction for advanced nuclear energy systems.

[0003] The lead-bismuth pump in the primary circuit of lead-cooled fast reactors (LFRs) can help the coolant overcome more circulation resistance and improve the unit mass power density of LFRs. It is the core component for controlling the cooling cycle during the operation of LFRs. The precise testing of the maximum flow rate and hydraulic performance of the lead-bismuth pump is of great significance. Summary of the invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a performance testing method for a liquid metal lead-bismuth pump, which can achieve accurate testing of the maximum flow rate and hydraulic performance of the lead-bismuth pump and ensure the performance of the lead-bismuth pump.

[0005] The present invention provides a performance testing method for a liquid metal lead-bismuth pump, comprising the following steps:

[0006] 1) Divide the flow channel of the lead-bismuth pump into a plurality of coaxial cylindrical flow surfaces, unfold the cylindrical surface into a plane along its generatrix, and obtain the plane blade cascade of the impeller blades on the cylindrical surface;

[0007] 2) Obtain fluid data and calculate the lead-bismuth pump head H;

[0008] H=(u2v u2 -u1v u1 ) / g;

[0009] Among them, u1 is the circumferential velocity of the fluid at the impeller inlet, and u2 is the circumferential velocity of the fluid at the impeller outlet;

[0010] v u1 is the circumferential component of the absolute velocity of the impeller inlet fluid, v u2 is the circumferential component of the absolute velocity of the fluid at the impeller outlet;

[0011] g is the acceleration due to gravity;

[0012] 3) Calculate the pressure difference between the inlet and outlet of the flow channel △ P;

[0013] △P=Hρg=(u2v u2 -u1v u1 )ρ;

[0014] Where, ρ is the density of lead-bismuth alloy;

[0015] 4) Calculate the maximum flow rate v of the lead-bismuth pump max and hydraulic efficiency η;

[0016]

[0017] Among them, v m1 is the axial velocity of the fluid at the impeller inlet;

[0018] u is the circumferential velocity obtained by decomposing the composite velocity v on the flow surface of a single blade;

[0019] Q is the mass flow rate of the lead-bismuth pump;

[0020] M is the total torque on the impeller surface;

[0021] ω is the impeller angular velocity.

[0022] Further, in the step 2):

[0023] v u1 =u1-v m1 / tanβ1;

[0024] v u2 =u2-v m2 / tanβ2;

[0025] Among them, β1 is the relative liquid flow angle at the impeller inlet, and β2 is the relative liquid flow angle at the impeller outlet;

[0026] v m2 is the axial velocity of the fluid at the impeller outlet.

[0027] Furthermore, the β1 and β2 are respectively:

[0028]

[0029] Furthermore, the composite flow velocity v on the flow surface of a single blade is decomposed to obtain the circumferential flow velocity u and the axial flow velocity m;

[0030]

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] The testing method of the present invention first divides the flow channel of the lead-bismuth pump into a plurality of coaxial cylindrical flow surfaces, unfolds the cylindrical surface into a plane along its generatrix, and obtains the plane blade grid of the impeller blades on the cylindrical surface; then obtains the fluid data, and then calculates the lead-bismuth pump head H and the pressure difference between the inlet and outlet of the flow channel △ P, maximum flow rate v of lead-bismuth pump max and hydraulic efficiency η; it realizes comprehensive and accurate performance testing of the lead-bismuth pump and ensures the performance of the lead-bismuth pump.

[0033] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0035] Figure 1 A flow chart of a performance test method for a liquid metal lead-bismuth pump;

[0036] Figure 2 It is the schematic diagram of the flow velocity triangle at the inlet and outlet of the impeller;

[0037] Figure 3 Schematic diagram of the plane cascade of blades. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0040] Please refer to Figure 1 to Figure 3 The embodiment of the present invention provides a performance test method of a liquid metal lead-bismuth pump, comprising the following steps:

[0041] 1) Divide the flow channel of the lead-bismuth pump into a plurality of coaxial cylindrical flow surfaces, unfold the cylindrical surface into a plane along its generatrix, and obtain the plane blade cascade of the impeller blades on the cylindrical surface;

[0042] 2) Obtain fluid data and calculate the lead-bismuth pump head H;

[0043] H=(u2v u2 -u1vu1 ) / g;

[0044] Among them, u1 is the circumferential velocity of the fluid at the impeller inlet, and u2 is the circumferential velocity of the fluid at the impeller outlet;

[0045] v u1 is the circumferential component of the absolute velocity of the impeller inlet fluid, v u2 is the circumferential component of the absolute velocity of the fluid at the impeller outlet;

[0046] g is the acceleration due to gravity;

[0047] v u1 =u1-v m1 / tanβ1;

[0048] v u2 =u2-v m2 / tanβ2;

[0049] Among them, β1 is the relative liquid flow angle at the impeller inlet, and β2 is the relative liquid flow angle at the impeller outlet;

[0050] v m1 is the axial velocity of the fluid at the impeller inlet, v m2 is the axial velocity of the fluid at the impeller outlet;

[0051]

[0052] Where u is the circumferential velocity obtained by decomposing the composite velocity v on the flow surface of a single blade;

[0053] The composite flow velocity v on the flow surface of a single blade is decomposed to obtain the circumferential flow velocity u and axial flow velocity m;

[0054]

[0055] 3) Calculate the pressure difference between the inlet and outlet of the flow channel △ P;

[0056] △P=Hρg=(u2v u2 -u1v u1 )ρ;

[0057] Where, ρ is the density of lead-bismuth alloy;

[0058] 4) Calculate the maximum flow rate v of the lead-bismuth pump max and hydraulic efficiency η;

[0059]

[0060] Where Q is the mass flow rate of the lead-bismuth pump;

[0061] M is the total torque on the impeller surface;

[0062] ω is the impeller angular velocity.

[0063] In this embodiment, when the performance test of the lead-bismuth pump is performed, the flow channel of the lead-bismuth pump is first divided into a plurality of coaxial cylindrical flow surfaces, and the cylindrical surface is unfolded into a plane along its generatrix to obtain the plane blade grid of the impeller blade on the cylindrical surface; then the fluid data is obtained, and then according to Figure 2 The flow rate triangle relationship shown in the figure is used to calculate the lead-bismuth pump head H and the pressure difference between the inlet and outlet of the flow channel △ P, maximum flow rate v of lead-bismuth pump max and hydraulic efficiency η, α in the velocity triangle diagram is the angle between the absolute velocity and the circumferential velocity, and w is the relative velocity of the impeller inlet and outlet; the testing method of the present application realizes comprehensive and accurate performance testing of the lead-bismuth pump, ensuring the performance of the lead-bismuth pump.

[0064] In the description of this specification, the description of the terms "one embodiment", "some embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A performance test method for a liquid metal lead-bismuth pump, characterized in that: The steps include: 1) Divide the flow channel of the lead-bismuth pump into a plurality of coaxial cylindrical flow surfaces, unfold the cylindrical surface into a plane along its generatrix, and obtain the plane blade cascade of the impeller blades on the cylindrical surface; 2) Obtain fluid data and calculate the lead-bismuth pump head H; H=(u2v u2 -u1v u1 ) / g; Among them, u1 is the circumferential velocity of the fluid at the impeller inlet, and u2 is the circumferential velocity of the fluid at the impeller outlet; v u1 is the circumferential component of the absolute velocity of the impeller inlet fluid, v u2 is the circumferential component of the absolute velocity of the fluid at the impeller outlet; g is the acceleration due to gravity; 3) Calculate the pressure difference between the inlet and outlet of the flow channel △ P; △P=Hρg=(u2v u2 -u1v u1 )ρ; Where, ρ is the density of lead-bismuth alloy; 4) Calculate the maximum flow rate v of the lead-bismuth pump max and hydraulic efficiency η; Among them, v m1 is the axial velocity of the fluid at the impeller inlet; u is the circumferential velocity obtained by decomposing the composite velocity v on the flow surface of a single blade; Q is the mass flow rate of the lead-bismuth pump; M is the total torque on the impeller surface; ω is the impeller angular velocity.

2. The performance testing method of the liquid metal lead bismuth pump according to claim 1 is characterized in that: In the step 2): v u1 =u1-v m1 / tanβ1; v u2 =u2-v m2 / tanβ2; Among them, β1 is the relative liquid flow angle at the impeller inlet, and β2 is the relative liquid flow angle at the impeller outlet; v m2 is the axial velocity of the fluid at the impeller outlet.

3. The performance testing method of the liquid metal lead bismuth pump according to claim 2 is characterized in that: The β1 and β2 are respectively:

4. The performance testing method of the liquid metal lead bismuth pump according to claim 3 is characterized in that: The composite flow velocity v on the flow surface of a single blade is decomposed to obtain the circumferential flow velocity u and axial flow velocity m;

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