Nuclear main pump lead bismuth lubrication guide bearing structure for negative feedback regulation

Abstract

The invention relates to a nuclear main pump lead-bismuth lubrication guide bearing structure for negative feedback regulation, and belongs to the technical field of systems of nuclear energy, high-temperature industry, energy and chemical industry, scientific research and the like. The bearing structure is internally provided with an even number of cylindrical pipelines and spiral pipelines which are circumferentially arranged, the inner wall of the bearing structure is sequentially provided with a feedback cavity, a high-pressure liquid tank, a liquid return tank and a working cavity in the axial direction, and the two ends of the spiral pipelines are connected with the feedback cavity and the working cavity respectively. The bearing capacity of the lead-bismuth lubrication guide bearing of the nuclear main pump is improved, the leakage problem is solved, and the lead-bismuth lubrication guide bearing is suitable for aerospace vehicle propulsion systems, ocean engineering deep sea equipment and the like.

Description

Technical Field

[0001] The invention relates to a lubricating guide bearing structure, belonging to the technical fields of nuclear energy, high temperature industry, energy chemical industry, scientific research and the like. Background Art

[0002] Lead-based reactors use lead-based materials (lead or lead alloys) as the primary coolant. Overall, lead-based reactor development is at the forefront of Generation IV nuclear energy systems, a consensus reached by international organizations, including the Generation IV Forum (GIF). Especially after nuclear accidents, unprecedented attention has been paid to nuclear safety. Lead-based reactors, with their excellent inherent safety, have become increasingly popular, significantly accelerating their development. Currently, multiple demonstration projects are underway worldwide, with plans for the development of lead-based reactors established.

[0003] High-temperature liquid lead-bismuth alloys have excellent thermal conductivity and chemical stability. The Generation IV Nuclear Energy Systems Forum has selected high-temperature liquid lead-bismuth metal as one of its target coolants. Flow pumps, with their low head, simple structure, and flexible installation, meet reactor heat transfer, structural installation, and safety design requirements, making them a key lead-bismuth pump design option.

[0004] Lead-bismuth-lubricated guide bearings in nuclear power main pumps drive the reactor coolant circulation within the reactor coolant system, transferring heat generated by the reactor core to the secondary circuit via the steam generator. These bearings are the heart of the reactor coolant system. Furthermore, they form part of the pressure boundary of the reactor coolant system, preventing the leakage of radioactive materials. Therefore, the operational stability of these bearings is crucial to the safety of the entire reactor coolant system.

[0005] Most of the existing lead-bismuth lubricated guide bearings have poor stability of the lubricating film during use, which is often affected by high temperature, high pressure and corrosion, leading to rupture or failure of the lubricating film. For example, water-lubricated bearings may undergo thermal deformation during operation due to poor cooling and lubrication effects, which in turn affects the material's load-bearing capacity. In severe cases, it may even cause the bearing to burn or get stuck. At the same time, the lubricating film of lead-bismuth lubricated guide bearings is particularly prone to further deterioration under high temperature conditions, resulting in reduced load-bearing capacity. When the lead-bismuth lubricated guide bearings are not designed properly, not only is the risk of leakage extremely high, but they are also prone to wear when running at high speed and under load, aggravating the damage to the lubricating film and further increasing the friction coefficient. Therefore, they fail to fully meet the stringent working conditions required by nuclear reactor cooling systems, fourth-generation reactors and fusion reactors, and nuclear physics research.

[0006] Therefore, it is urgent to propose a lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation to solve the above technical problems. Summary of the Invention

[0007] To address the issues of insufficient load-bearing capacity and leakage in lead-bismuth-lubricated guide bearings for nuclear main pumps, a lead-bismuth-lubricated guide bearing structure for nuclear main pumps with negative feedback regulation is provided. A brief overview of the invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive overview of the invention. It is not intended to identify key or important aspects of the invention, nor is it intended to limit the scope of the invention.

[0008] The technical solution of the present invention:

[0009] A lead-bismuth lubricated guide bearing structure for a nuclear main pump used for negative feedback regulation. The bearing structure has an even number of cylindrical pipes and spiral pipes arranged circumferentially. The inner wall of the bearing structure has a feedback chamber, a high-pressure liquid tank, a return liquid tank, and a working chamber in sequence along the axial direction. The two ends of the spiral pipe are respectively connected to the feedback chamber and the working chamber.

[0010] Preferably, the bearing structure is a circular tube type, the center of the bearing structure is a cylindrical inner cavity of equal diameter, and the outer diameter of the input side of the bearing structure is greater than the outer diameter of the output side.

[0011] Preferably, spiral pipes are machined in the bearing structure and are evenly arranged in the circumferential direction.

[0012] Preferably, the number of the spiral pipes is an even number.

[0013] Preferably, the spiral pipe is a 1 / 2 spiral.

[0014] Preferably, a cylindrical pipe is provided between adjacent spiral pipes, and the cylindrical pipe is a through hole of equal diameter processed along the axial direction.

[0015] Preferably, the spiral pipe is located outside the cylindrical pipe, and both ends of the spiral pipe are connected to the feedback chamber and the working chamber through a radial pipe.

[0016] Preferably, the high-pressure liquid tank and the return liquid tank are both annular, and are connected to the return liquid tank through a cylindrical pipe and a bearing gap.

[0017] Preferably, the volume of the high-pressure liquid tank is larger than that of the return liquid tank.

[0018] Preferably, an annular groove and a longitudinal groove are further included, longitudinal grooves are provided between adjacent feedback chambers, and a number of evenly arranged annular grooves are provided between the high-pressure liquid tank and the return liquid tank.

[0019] The present invention has the following beneficial effects:

[0020] The present invention applies planar microtexturing technology to the inner wall of the guide bearing, creating an annular groove on the inner wall of the guide bearing. A prominent feature of the present invention is that the groove texture has a certain groove pressurization effect. The increased pressure in the groove reduces the pressure difference between the inlet and the groove, resulting in a reduced flow rate, thereby reducing the leakage of the lead-bismuth alloy mixture.

[0021] The lead-bismuth lubricated guide bearing configuration of the nuclear main pump of the present invention is not limited to the cavity and groove structure direction, and can meet any working condition requiring negative feedback regulation, thus having a certain degree of universality.

[0022] The structure of the lead-bismuth lubricated guide bearing of the nuclear main pump of the present invention is not limited to materials, including but not limited to high-strength materials, alloy materials, high-temperature and high-pressure materials and other materials that can adapt to extremes; the guide bearing has a relatively firm connection effect while ensuring an obvious sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a stereoscopic diagram of the lead-bismuth lubricated guide bearing structure of a nuclear main pump used for negative feedback regulation.

[0024] Figure 2 It is a cross-sectional view of the lead-bismuth lubricated guide bearing structure of a nuclear main pump used for negative feedback regulation.

[0025] Figure 3 This is a fluid model diagram of a lead-bismuth lubricated guide bearing structure of a nuclear main pump used for negative feedback regulation.

[0026] Figure 4 It is the structural layout diagram of the spiral pipeline.

[0027] Figure 5 This is a cross-sectional dimensional drawing of a lead-bismuth lubricated guide bearing structure for a nuclear main pump used for negative feedback regulation.

[0028] Figure 6 yes Figure 5 Enlarged view of point B in the middle.

[0029] Figure 7 It is a top view of the lead-bismuth lubricated guide bearing structure of a nuclear main pump used for negative feedback regulation.

[0030] Figure 8 This is a lubricant flow diagram for a lead-bismuth lubricated guide bearing structure of a nuclear main pump used for negative feedback regulation.

[0031] Figure 9 It is the working area of the lead-bismuth lubricated guide bearing structure of a nuclear main pump used for negative feedback regulation.

[0032] Figure 10 It is the influence of the annular guide groove of the guide bearing on the maximum and minimum pressure, bearing capacity and friction factor at different speeds.

[0033] Figure 11 It is the influence of the number of grooves of the guide bearing on the maximum and minimum pressure, load capacity and friction factor.

[0034] In the figure, 1-cylindrical pipe, 2-working chamber, 3-return liquid tank, 4-high-pressure liquid tank, 5-feedback chamber, 6-spiral pipe, 7-annular groove, 8-longitudinal groove. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the present invention more clearly apparent, the present invention is described below using specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely illustrative and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0036] Specific implementation method 1: Combination Figure 1-9 The present embodiment is described. The present embodiment is a lead-bismuth lubricated guide bearing structure of a nuclear main pump for negative feedback regulation. The bearing structure has an even number of cylindrical pipes 1 and spiral pipes 6 arranged circumferentially. The inner wall of the bearing structure has a feedback chamber 5, a high-pressure liquid tank 4, a return liquid tank 3, and a working chamber 2 in axial order from the input end to the output end. The two ends of the spiral pipe 6 are respectively connected to the feedback chamber 5 and the working chamber 2; the lead-bismuth alloy mixture is used as a lubricant to mainly form a liquid film for dynamic and static pressure lubrication; the cylindrical pipe 1, the spiral pipe 6, the feedback chamber 5, the high-pressure liquid tank 4, the return liquid tank 3, and the working chamber 2 are non-lubricated area fluid models, and the gap between the shaft strength of the guide bearing and the bearing forms a lubricated area fluid model; the bearing structure is high-strength alloy steel, generally 316L stainless steel or Inconel 718; The medium inside the lead-bismuth pump is LBE alloy, the eutectic composition of which is 44.5% lead (Pb) and 55.5% bismuth (Bi) by mass. The guide bearing involved in the present invention increases its load-bearing capacity by adding an adjustment chamber to obtain more lead-bismuth alloy mixed liquid. The present invention improves the load-bearing capacity of the lead-bismuth lubricated guide bearing of the nuclear main pump and solves the leakage problem. It is suitable for aerospace propulsion systems, marine engineering deep-sea equipment, etc.

[0037] The bearing structure is a circular tube type, the center of the bearing structure is a cylindrical inner cavity of equal diameter, and the outer diameter of the input side of the bearing structure is larger than the outer diameter of the output side; Figure 1 The radial plane where the upper edge of the high-pressure liquid tank 3 of the bearing structure in the middle direction is located is the dividing line, dividing the bearing structure into an upper working area and a lower adjustment area;

[0038] The bearing structure is machined with spiral pipes 6 evenly distributed along the circumference. The lead-bismuth lubricated guide bearing of the nuclear main pump is a multi-zone structure, consisting of a working zone and an adjustment zone from top to bottom. The shapes of the two zones are axially symmetrical, with cylindrical pipes and spiral grooves evenly distributed along the circumference, which has a pressurizing effect.

[0039] The number m of spiral conduits 6 is an even number, and the spiral conduits 6 are 1 / 2 spirals (a spiral shape rotated 180 degrees around the central axis). The spiral conduits 6 achieve the purpose of negative feedback regulation. The self-lubricating property is characterized by a half-turn spiral groove connecting the regulating chamber with its opposite working chamber. The half-turn spiral groove structure is the key to achieving self-regulation of the guide bearing.

[0040] One end of the spiral pipe 6 is corresponding to a feedback chamber 5, and the other end of the spiral pipe 6 is corresponding to a working chamber 2. Figure 4 As shown, the feedback chamber 5 and the working chamber 2 corresponding to the two ends of the same spiral pipe 6 are arranged symmetrically in AA, so that the number of feedback chambers 5 and working chambers 2 is the same as the number of spiral pipes 6, and the feedback chambers 5 and working chambers 2 are evenly arranged circumferentially; the circumferentially evenly distributed working chambers and feedback chambers meet the normal working needs and feedback regulation of the equipment system; caused by the spiral groove, the spiral groove can connect the feedback chamber and the corresponding working chamber, and realize negative feedback regulation through the feedback chamber and the return liquid groove;

[0041] Two cylindrical pipes 1 are provided between adjacent spiral pipes 6. The cylindrical pipes 1 are through holes of equal diameter processed in the axial direction. The two cylindrical pipes 1 form a pipe group. The pipe group is evenly arranged in the circumferential direction, so that the number of pipe groups is the same as the number of spiral pipes 6, and the number n of cylindrical pipes 1 is an even number. The cylindrical pipes are evenly arranged in the circumferential direction and are cylindrical pipes of equal thickness from top to bottom in the axial direction. The spiral grooves are spirally arranged in the axial direction and are square pipes evenly distributed in the spiral direction.

[0042] The spiral pipe 6 is located outside the cylindrical pipe 1. Both ends of the spiral pipe 6 are connected to the feedback chamber 5 and the working chamber 2 through a radial pipe, so that the spiral pipe 6 and the cylindrical pipe 1 are not connected in the side wall of the bearing structure. Sufficient processing dimensions are reserved for the cylindrical pipe 1, the high-pressure liquid tank 4, and the return liquid tank 3, meeting functional requirements and having a compact and reasonable design.

[0043] The high-pressure liquid tank 4 and the return liquid tank 3 are both annular, and the high-pressure liquid tank 4 and the return liquid tank 3 are connected through the cylindrical pipe 1, that is, the high-pressure liquid tank 4 and the return liquid tank 3 divide the cylindrical pipe 1 into three sections. The first section of the cylindrical pipe, the high-pressure liquid tank 4, the second section of the cylindrical pipe, the return liquid tank 3, and the third section of the cylindrical pipe are connected in sequence. A longitudinal groove connected to the return liquid tank 3 is added between the regulating chambers, and the high-pressure lead-bismuth alloy mixture flows from the return liquid tank 3 into the longitudinal groove, so that the regulating chamber can obtain the high-pressure lead-bismuth mixture from the top, bottom, left and right directions. The four directions refer to: the return liquid tank 3 at the top, the bearing clearance at the bottom, and the longitudinal grooves on the left and right sides. The bearing clearance is the clearance when cooperating with the shaft system during operation; the two annular guide grooves of the return liquid tank and the high-pressure liquid tank have the function of reducing leakage, realizing high load and feedback regulation; the high load capacity is improved by increasing the content of the lead-bismuth alloy mixture in the regulating chamber, and the high load function. The structural design of the present invention can withstand the high load of the nuclear main pump, ensuring stable operation of the system under extreme conditions;

[0044] The high-pressure liquid tank 4 is larger in volume than the return liquid tank 3, and the axial length of the feedback chamber 5 is much smaller than the circumferential length of the working chamber 2, making the working chamber 2 larger in volume than the feedback chamber 5. By making the volume of the return liquid tank 3 smaller than that of the high-pressure liquid tank 4, the high-pressure liquid tank 4 is a high-pressure liquid tank for storing more liquid, thereby achieving a buffering effect on the guide bearing structure caused by the incoming liquid. A portion of the lead-bismuth alloy mixture in the return liquid tank 3 enters the high-pressure liquid tank 4 through the cylindrical pipe 1 in the bearing clearance, and then flows out of the guide bearing through the liquid outlet hole of the cylindrical pipe 1. This portion of the mixed liquid does not contribute to any leakage.

[0045] It also includes annular grooves 7 and longitudinal grooves 8. A longitudinal groove 8 is set between adjacent feedback chambers 5. Several evenly arranged annular grooves 7 are set between the high-pressure liquid tank 4 and the return liquid tank 3. The annular grooves 7 are groove-textured annular grooves. The number of annular grooves 7 is an even number and is evenly spaced along the axial direction. The distance from the edge annular groove 7 to the feedback chamber 5 or the longitudinal groove 8 is x1=2mm, the distance between the feedback chamber 5 and the longitudinal groove 8 is x3=115mm, the width of the annular groove 7 is x2=5mm, and the depth of the annular groove 7 is x4=5mm. The pressurization effect is caused by the plane transverse groove texture annular groove 7. The increase in pressure at the groove reduces the pressure difference between the inlet and the groove, resulting in a reduction in flow rate. To reduce the leakage of the lead-bismuth alloy mixture, it is necessary to open an annular groove between the high-pressure liquid tank 4 and the return liquid tank 3 on the inner wall of the bearing, and the plane micro-texture technology Applied to the inner wall of the guide bearing, an annular groove is formed on the inner wall of the bearing to reduce the leakage of the lead-bismuth alloy mixture. The present invention also takes into account practical engineering problems and solves the problem in the prior art that, in the process of part of the mixed liquid in the return liquid tank 3 entering the high-pressure liquid tank 4 through the bearing gap and then flowing out of the bearing through the liquid outlet, this part of the mixed liquid is lost without playing any role. The planar transverse groove texture of the present invention has a certain groove pressurization effect. The increased pressure in the groove reduces the pressure difference between the inlet and the groove, resulting in a reduction in flow rate. The optimized structural design realizes a close connection between the lead-bismuth lubricated guide bearing and other mechanical parts of the nuclear main pump, and can ensure the sealing and reliability of the connection. It is easy to process and assemble, and it is also convenient to modify existing components, which is convenient for cost control and has a very wide range of applications.

[0046] The lead-bismuth alloy mixture at the lower inlet of the cylindrical pipe 1 enters the high-pressure liquid tank 4 through the first section of the cylindrical pipe 1. The liquid in the high-pressure liquid tank 4 enters the feedback chamber 5 through the bearing gap, that is, the liquid at the lower inlet enters the regulating chamber through the bearing gap. The liquid in the regulating chamber flows into the spiral pipe 6. Part of the liquid in the high-pressure liquid tank 4 flows upward through the bearing gap into the return liquid tank 3. The liquid in the spiral pipe 6 flows into the working chamber 2. The liquid in the working chamber flows upward, and the liquid in the working chamber 2 flows downward. The liquid in the working chamber 2 flows downward through the bearing gap into the high-pressure liquid tank 3. The liquid in the working chamber (working chamber 2) flows upward through the bearing gap. The liquid in the return liquid tank 3 flows out of the guide bearing through the liquid outlet hole at the upper end of the cylindrical pipe. The present invention utilizes the stability of the performance of lead-bismuth alloy at high temperatures, which is suitable for the high-temperature environment of the nuclear reactor, ensures coolant circulation, and achieves the effect of maintaining the reactor temperature. The lead-bismuth alloy mixture is used as a lubricant to reduce friction and wear between mechanical parts, thereby achieving the purpose of improving efficiency. The lead-bismuth lubricated guide bearing structure is designed to withstand the high load capacity of the nuclear main pump, ensuring the stable operation of the system under extreme conditions. The lead-bismuth alloy mixture has self-lubricating properties, which reduces the need for external lubrication and reduces maintenance costs.

[0047] Example 1:

[0048] Combined with attachment Figures 1-11 The present invention proposes a design for a lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation. Through this structural design, the load-bearing capacity and leakage of the guide bearing can be regulated. The present invention effectively improves the load-bearing capacity of the guide bearing. The flat transverse groove texture, which acts as a groove pressurization mechanism, improves the airtightness and connection reliability of the groove texture. Most notably, the increased pressure at the groove reduces the pressure difference between the inlet and the groove, resulting in a reduced flow rate and increased reusability of the bismuth alloy mixture.

[0049] In this embodiment, eight longitudinal grooves connected to the liquid return groove 3 are added between the eight regulating chambers. The high-pressure lead-bismuth alloy mixture flows from the liquid return groove 3 into the longitudinal grooves, allowing the regulating chamber to obtain the high-pressure lead-bismuth alloy mixture from four directions: up, down, left, and right. Therefore, the carrying capacity can be improved by increasing the content of the mixture obtained by the regulating chamber.

[0050] In the embodiment of the present invention, a planar transverse groove texture is used for groove pressurization. The increased pressure at the groove reduces the pressure difference between the inlet and the groove, resulting in a reduced flow rate. The planar micro-texturing technology is applied to the inner wall of the guide bearing, and an annular groove is formed on the inner wall of the guide bearing to reduce the leakage of the lead-bismuth alloy mixture.

[0051] The guide bearing used in this embodiment is made of high-strength alloy steel, typically 316L stainless steel or Inconel 718. The medium inside the lead-bismuth pump is LBE alloy. The lead-bismuth alloy mixture is filled between the chamber and the groove structure, which acts as a pressure booster.

[0052] (1) Assembly of the lead-bismuth lubricated guide bearing of the nuclear main pump for negative feedback regulation. The parameters used in the calculation are: number of liquid inlet and outlet holes n = 16, D1 = 1030 mm, D2 = 900 mm, D3 = 699.80 mm, h1 = 1035 mm, h2 = 855 mm;

[0053] (2) Lead-bismuth lubricated guide bearing structure of the nuclear main pump;

[0054] The structural parameters of the guide bearing are: n=16, m=8, D1=1030mm, D2=900mm, D3=699.80mm, h1=1035mm, h2=855mm, l1=694.62mm, l2=80mm, R1=425mm, R2=445mm, R3=350mm, t1=30mm, t2=60mm, α1=30°, α2=15°, β=90°, a=125mm, b=14.37mm, c=140.20mm, d=300mm, r1=20mm, r2=20mm, e=111.69mm, f=14.37mm, o=140.2mm, r3=20mm, r4=40mm. The hydraulic performance calculation model parameters are: n = 16, m = 8, D3 = 699.80 mm, h1 = 1035 mm, l1 = 694.62 mm, l2 = 80 mm, R1 = 425 mm, R2 = 445 mm, R3 = 350 mm, t1 = 30 mm, t2 = 60 mm, α1 = 30°, α2 = 15°, β = 90°, a = 125 mm, b = 14.37 mm, c = 140.20 mm, d = 300 mm, r1 = 20 mm, r2 = 20 mm, e = 111.69 mm, f = 14.37 mm, o = 140.2 mm, r3 = 20 mm, r4 = 40 mm;

[0055] (3) Calculation model of hydraulic performance of lead-bismuth lubricated guide bearing of nuclear main pump, including non-lubricated area and lubricated area;

[0056] The non-lubricated area is a model in which the bearing fluid model has various pipes and chambers in addition to the lubricating film area. Its parameters are: n = 16, m = 8, h1 = 1035 mm, l1 = 694.62 mm, l2 = 80 mm, R1 = 425 mm, R2 = 445 mm, R3 = 350 mm, t1 = 30 mm, t2 = 60 mm, α1 = 30°, α2 = 15°, β = 90°, a = 125 mm, b=14.37mm, c=140.20mm, d=300mm, r1=20mm, r2=20mm, e=111.69mm, f=14.37mm, o=140.2mm, r3=20mm, r4=40mm; the lubrication area is the clearance area between the spindle and the bearing, and its parameters are: D3=699.80mm, h1=1035mm, D4=700mm. The parameters of the guide bearing liquid film model are: m=8, D3=699.80mm, D4=700mm, h1=1035mm, h3=600mm, α1=30°, α2=15°, a=125mm, b=14.37mm;

[0057] (4) Calculation model of hydraulic performance of the lead-bismuth lubricated guide bearing without annular guide groove for the nuclear main pump;

[0058] The non-lubricated area is a model in which the bearing fluid model has various pipes and chambers in addition to the lubricating film area. Its parameters are: n = 16, m = 8, h1 = 1035 mm, l1 = 694.62 mm, l2 = 80 mm, R1 = 425 mm, R2 = 445 mm, R3 = 350 mm, t1 = 30 mm, t2 = 60 mm, α1 = 30°, α2 = 15°, β = 90°, a = 125 mm, b=14.37mm, c=140.20mm, d=300mm, r1=20mm, r2=20mm, e=111.69mm, f=14.37mm, o=140.2mm, r3=20mm, r4=40mm; the lubrication area is the clearance area between the spindle and the bearing, and its parameters are: D3=699.80mm, h1=1035mm, D4=700mm. The parameters of the guide bearing liquid film model are: m=8, D3=699.80mm, D4=700mm, h1=1035mm, h3=600mm, α1=30°, α2=15°, a=125mm, b=14.37mm;

[0059] (5) Calculation model of hydraulic performance of lead-bismuth lubricated guide bearing of nuclear main pump, including 6 working chambers and 6 feedback chambers;

[0060] The relevant parameters of the structural optimization design of the lead-bismuth lubricated guide bearing of the nuclear main pump for negative feedback regulation are: n = 16, m = 8, z = 6, D1 = 1030 mm, D2 = 900 mm, D3 = 699.80 mm, h1 = 1035 mm, h2 = 855 mm, l1 = 694.62 mm, l2 = 80 mm, R1 = 425 mm, R2 = 445 mm, R4 = 355 mm, R3 = 350 mm, t1 = 30 m m, t2=60mm, t3=10mm, α1=30°, α2=15°, β=90°, a=125mm, b=14.37mm, c=140.20mm, d=300mm, r1= 20mm, r2=20mm, e=111.69mm, f=14.37mm, o=140.2mm, p=61.38mm, q=115mm, r3=20mm, r4=40mm;

[0061] Among them, h1 is the total axial height, h2 is the inlet side height (axial height of the side with larger outer diameter), a is the width of the working chamber, b is the depth of the working chamber, e is the width of the feedback chamber, f is the depth of the feedback chamber, l1 is the distance from the bottom surface to the center of the working chamber, l2 is the distance from the bottom surface to the feedback chamber, R1 is the radius of the return liquid groove, R2 is the radius of the high-pressure liquid groove, R3 is the cylindrical radius of the fluid model in the lubrication area, t1 is the groove width of the return liquid groove, t2 is the groove width of the high-pressure liquid groove, c is the distance between the vertices of two adjacent working chambers or feedback chambers, d is the distance from the center of the working chamber to the edges of the upper and lower chambers, r1 and r2 are the fillets of the working cavity, r3 is the radius of the connecting tube between the cavity and the spiral groove, and r4 is the side length of the quadrilateral of the spiral groove cross section. The present invention provides specific processing dimensions, which can not only significantly improve the accuracy and efficiency of mechanical processing, but also reduce costs and extend equipment life, which is conducive to promoting technological innovation and industrial upgrading. These effects are of great significance to the development of the manufacturing industry. At the same time, during the simulation process, the deviation between the simulation results and the actual performance is reduced, the reliability of the design is improved, the time is shortened, and the calculation time cost, modification cost, and testing cost are reduced, which is conducive to improving bearing performance.

[0062] The present invention utilizes the negative feedback regulation characteristics of the lead-bismuth lubricated guide bearing in the nuclear main pump to develop a structural design that can produce more lead-bismuth alloy mixed liquid to improve load-bearing capacity. Simultaneously, planar microtexturing technology is applied to the inner wall of the guide bearing, creating annular grooves on the inner wall of the bearing to reduce leakage. Because the present invention is a negative feedback regulation lead-bismuth lubricated guide bearing structural design for the nuclear main pump, it can provide new ideas for further development of bearing design.

[0063] According to the dimensions of each component in the embodiment, ANSYS WORKBENCH software was used for simulation calculation; Figure 10-11 The results show that when the annular guide groove is considered, the positive and negative pressure bearing areas are concentrated above the groove, that is, the area where the annular guide groove is located. However, if the positive and negative pressure bearing areas of the annular guide groove are not considered, the dynamic pressure effect is concentrated between the grooves. The main reason for this difference is that the annular guide groove is the same as the guide hole at the pressure inlet, which can guide the lead-bismuth alloy lubricating fluid at the pressure inlet, thereby achieving a pressure relief effect.

[0064] Furthermore, to investigate the influence of groove number on lubrication performance, the present invention selected typical groove numbers of 8 and 6 for analysis. The load capacity and friction coefficient for both 8 and 6 grooves increased with increasing eccentricity, but the overall load capacity and friction coefficient curves for 8 grooves were greater than those for 6 grooves. Therefore, there is considerable room for optimization design with respect to groove number to achieve optimal bearing performance, including increased load, reduced drag, vibration, and noise reduction.

[0065] Therefore, the lead-bismuth lubricated guide bearing of the nuclear main pump for negative feedback regulation in the embodiment of the present invention is structurally optimized. The outstanding technical feature of the present invention is that it adopts a structural design with additional regulating chambers to achieve a higher load-bearing capacity. This is mainly achieved by adding a longitudinal groove connected to the liquid return groove 3 between the regulating chambers. The high-pressure lead-bismuth alloy mixture flows from the liquid return groove 3 into the longitudinal groove, allowing the regulating chamber to receive the high-pressure lead-bismuth alloy mixture from four directions: top, bottom, left, and right.

[0066] In summary, the embodiments of the present invention apply planar microtexturing technology to the inner wall of the guide bearing, providing annular grooves therein. A prominent feature of the present invention is that the groove texture has a certain groove pressurization effect. The increased pressure at the groove reduces the pressure difference between the inlet and the groove, resulting in a reduced flow rate, thereby reducing leakage of the lead-bismuth alloy mixture.

[0067] The lead-bismuth lubricated guide bearing configuration of the nuclear main pump of the present invention is not limited to the cavity and groove structure direction, and can meet any working condition requiring negative feedback regulation, thus having a certain degree of universality.

[0068] The lead-bismuth lubricated guide bearing for the nuclear main pump of the present invention is not limited to materials, including but not limited to high-strength materials, alloy materials, high-temperature and high-pressure materials, and other materials that can adapt to extreme conditions. The guide bearing ensures a significant sealing effect while also providing a relatively strong connection effect.

[0069] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutations and combinations. Therefore, the present invention will no longer describe the technical solutions after permutations and combinations one by one, but it should be understood that the technical solutions after permutations and combinations have been disclosed by the present invention.

[0070] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation, characterized by: The bearing structure has an even number of cylindrical pipes (1) and spiral pipes (6) arranged circumferentially. The inner wall of the bearing structure has a feedback chamber (5), a high-pressure liquid tank (4), a return liquid tank (3), and a working chamber (2) in sequence along the axial direction. The two ends of the spiral pipe (6) are respectively connected to the feedback chamber (5) and the working chamber (2).

2. The lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 1, characterized in that: The bearing structure is a circular tube type, the center of the bearing structure is a cylindrical inner cavity with equal diameter, and the outer diameter of the input side of the bearing structure is greater than the outer diameter of the output side.

3. A lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 1 or 2, characterized in that: A spiral pipe (6) evenly arranged in the circumferential direction is processed in the bearing structure.

4. The lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 3, characterized in that: The number of the spiral pipes (6) is an even number.

5. The lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 3, characterized in that: The spiral pipe (6) is a 1 / 2 spiral.

6. The lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 5, characterized in that: A cylindrical pipe (1) is provided between adjacent spiral pipes (6), and the cylindrical pipe (1) is a through hole of equal diameter processed along the axial direction.

7. The lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 6, characterized in that: The spiral pipe (6) is located outside the cylindrical pipe (1), and both ends of the spiral pipe (6) are connected to the feedback chamber (5) and the working chamber (2) through a radial pipe.

8. The lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 7, characterized in that: The high-pressure liquid tank (4) and the return liquid tank (3) are both annular, and the high-pressure liquid tank (4) and the return liquid tank (3) are connected through a cylindrical pipe (1).

9. The lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 8, characterized in that: The volume of the high-pressure liquid tank (4) is greater than that of the return liquid tank (3).

10. The lead-bismuth lubricated guide bearing structure for a nuclear main pump for negative feedback regulation according to claim 1, characterized in that: It also includes an annular groove (7) and a longitudinal groove (8). The longitudinal groove (8) is provided between adjacent feedback chambers (5), and a plurality of evenly arranged annular grooves (7) are provided between the high-pressure liquid tank (4) and the return liquid tank (3).

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