Marine high-flow oblique flow circulating water pump

Abstract

The utility model relates to a kind of marine high-flow oblique flow circulating water pump, belong to marine machinery technical field, the utility model is to solve the problem of traditional marine axial flow pump in the high lift, large flow condition needed by marine cooling system, efficiency is low, volume loss is big, operation stability is not good.The utility model core uses oblique flow impeller structure, impeller is equipped with 3 only by specific space section line dynamic blade, its section line is positioned by space coordinate point design, so that blade section from water inlet side to water outlet side smooth transition, working surface and back surface section line are relatively reference line continuous, regular deviation, realize in 0.85Q s 1.3Q s Wide flow range to the high-efficiency matching of multiple lift. The key innovation is that the surface of the conical top annular chamber of the impeller is provided with five evenly distributed wedge-shaped grooves. This structure can form a reverse pressure balance area, effectively reducing the volume loss, while reducing vibration and noise and improving the cavitation performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of marine machinery, and particularly relates to a large-flow inclined flow circulating water pump for cooling of a marine power system. BACKGROUND

[0002] With the rapid development of modern ocean-going ships towards large-scale, high-speed and intelligentization, the single-machine power of the ship power system continues to increase substantially. The heat load generated by the main engine and auxiliary engine of the new generation of ships represented by large container ships, liquefied natural gas (LNG) transport ships and luxury cruise ships has increased exponentially, which has put unprecedentedly stringent requirements on the heat dissipation capacity of the matching cooling system. As the core power source of the cooling system, the circulating water pump not only needs to provide a much larger flow than before, but also must ensure a high enough delivery head to overcome the increasing resistance of the cooling pipeline system, so as to ensure that the cooling medium can be stably and efficiently circulated at each heat exchange node of the ship.

[0003] At present, the cooling water pump widely used in the field of ships is still mainly the traditional axial flow pump. Although this type of pump has the advantages of relatively simple structure and low operating cost in the large flow range, its inherent characteristics have obvious bottlenecks. First, the head-flow curve of the axial flow pump is too flat, and it is prone to "saddle-shaped" hump in some operating conditions, resulting in poor operating stability, especially in the actual application of ships with frequent variable conditions, which easily causes system pressure fluctuation and cavitation risk. Second, the high efficiency zone of the axial flow pump is narrow, and when the system demand head is slightly higher than the design point, the efficiency will decrease sharply and the energy consumption will increase significantly. If the method of increasing the impeller diameter or increasing the speed is simply adopted to meet the higher head requirement, not only will it result in excessive length of the pump set in the axial direction and excessive space occupied in the radial direction, which will seriously conflict with the design requirements of the high space utilization of the ship engine room, but also will cause a series of derivative problems such as increased vibration, increased noise, shortened bearing life, and further deteriorated cavitation performance.

[0004] In order to achieve the balance of "large flow" and "relatively high lift" in limited space, mixed flow pump (mixed flow pump) as a potential technical route has been concerned. The flow passage design of mixed flow pump is between axial flow pump and centrifugal pump, the fluid has both axial and radial movement in the impeller, which can theoretically provide higher single-stage lift than axial flow pump, while maintaining good large flow characteristics. However, the successful application of mixed flow pump in ship circulating water system still faces great challenges: first, the conventional mixed flow pump blade profile design often comes from general industrial model, which cannot be deeply optimized for the specific, wide range of flow-lift matching conditions of ship cooling system, resulting in serious efficiency decay in actual ship variable operating conditions; second, the gap leakage (volume loss) between the impeller and the static part of the pump body is particularly significant under high pressure difference, and the traditional structure is insufficient to control it, which directly restricts the further improvement of pump efficiency; third, the lack of integrated design for seawater corrosion, cavitation corrosion and special vibration environment of ship affects the long-term operation reliability and maintenance cost of the pump set.

[0005] Therefore, there is an urgent need in the art for a mixed flow circulating water pump specially designed for the large flow cooling condition of ship. The pump type needs to be fundamentally innovatively designed, and the core is to develop a new and high-performance impeller hydraulic model, including a blade profile that can adapt to wide operating conditions and efficiently run, and an impeller top structure that can effectively suppress gap leakage and improve pressure distribution. Through such comprehensive design, the operating efficiency, stability and reliability of the pump set can be substantially improved without significantly increasing the space occupation, meeting the cooling needs of modern high-performance ship power systems. SUMMARY

[0006] In order to solve the problems of low efficiency, large volume loss and poor running stability of traditional ship axial flow pump under high lift and large flow conditions required by ship cooling system, the present application provides a ship large flow mixed flow circulating water pump.

[0007] The ship large flow mixed flow circulating water pump provided by the present application comprises a pump shaft, an impeller mounted on the pump shaft, and a pump body assembly wrapped outside the impeller, wherein the pump body assembly forms a flow passage from an inlet bellows to an outlet bellows; the pump shaft is assembled with an upper shaft sleeve and a lower shaft sleeve, and is supported on the pump body assembly by upper and lower rubber bushings, respectively;

[0008] The top annular chamber surface of the impeller is provided with five evenly distributed wedge-shaped grooves, the longitudinal section angle of the wedge-shaped grooves is , the wedge-shaped groove bevel is inclined to the vertical direction at an angle of , the groove width L of the wedge-shaped groove is , and the shortest distance H of the longitudinal section of the wedge-shaped groove is .

[0009] Preferably, the impeller has 3 blades;

[0010] A spatial coordinate system is defined for the blade profile, with the center of the impeller as the origin;

[0011] The leading edge of the blade pressure surface on the shroud side is defined as the a-a line, and the trailing edge on the hub side is defined as the c-c line;

[0012] The leading edge of the blade suction surface on the shroud side is defined as the b-b line, and the trailing edge on the hub side is defined as the d-d line;

[0013] The radial distance of the closest point on the a-a line to the origin is taken as the reference distance Y;

[0014] On the blade pressure surface, a set of characteristic lines extending from the a-a line to the c-c line is defined, labeled in order as A line, B line, C line, D line, E line, F line, G line, H line, I line, and J line;

[0015] On the blade suction surface, a corresponding set of characteristic lines extending from the b-b line to the d-d line is defined, labeled in order as line, line, line, line, line, line, line, line, line, line;

[0016] A 0° reference plane is defined as the plane passing through the impeller inlet edge and centered on the origin;

[0017] Twelve radial sections centered on the origin and surrounding the impeller axis at specific angular intervals from the 0° reference plane are defined, labeled in order from the hub side to the shroud side as Section I, Section II, Section III, Section IV, Section V, Section VI, Section VII, Section VIII, Section IX, Section X, Section XI, and Section XII;

[0018] The profile of the blade pressure surface is defined by the coordinates of the intersection points of each characteristic line (A line to J line) with each radial section (I to XII), with the radial coordinate values of each intersection point referenced to the reference distance Y, and the specific values as follows:

[0019] On the a-a line: the reference point coordinate is Y, the intersection point with the A line is Y-52.1, the intersection point with the B line is Y-104.2, the intersection point with the C line is Y-156.3, and the corresponding point on the c-c line is Y-206.6;

[0020] Intersection of section I with lines: a-a line Y+7.8, A line Y-15.4, B line Y-66, C line Y-116.7, D line Y-167.5, c-c line Y-196.3;

[0021] Intersection of section II with lines: a-a line Y+13.8, A line Y+13.3, C line Y-81.7, D line Y-129.1, E line Y-176.7, c-c line Y-185.3;

[0022] Intersection of section III with lines: a-a line Y+21, C line Y-47.2, D line Y-92.7, E line Y-138.1, c-c line Y-174.3;

[0023] Intersection of section IV with lines: a-a line Y+28.3, C line Y-14, D line Y-57.2, E line Y-100.6, F line Y-143.8, c-c line Y-162.7;

[0024] Intersection of section V with lines: a-a line Y+36.3, C line Y+19.3, D line Y-22.6, E line Y-64.5, F line Y-106.4, G line Y-148.4, c-c line Y-151.3;

[0025] Intersection of section VI with lines: a-a line Y+43.6, D line Y+8.8, E line Y-30.8, F line Y-70.2, G line Y-109.7, c-c line Y-139.1;

[0026] Intersection of section VII with lines: a-a line Y+53, D line Y+44.9, E line Y+6.4, F line Y-32.1, G line Y-70.7, H line Y-109.2, c-c line Y-126.4;

[0027] Intersection of section VIII with lines: a-a line Y+53.1, E line Y+40.8, F line Y+3.2, G line Y-34.4, H line Y-72, I line Y-109.7, c-c line Y-114.3;

[0028] Intersection of section IX with lines: a-a line Y+73.8, F line Y+45.3, G line Y+6.4, H line Y-32.4, I line Y-71.4, c-c line Y-102.2;

[0029] Intersection of section X with lines: H line Y+16.3, I line Y-28.6, J line Y-73.7, c-c line Y-91.4;

[0030] Intersection of section XI with each line: c-c line is Y-82.1;

[0031] Intersection of section XI with each line: c-c line is Y-82.1;

[0032] Preferably, the profile of the blade back surface is defined by the back surface line to The intersection coordinates of the characteristic profile line of each line with the twelve radial sections of the back surface are defined by the radial coordinate values of each intersection, with reference to the reference distance Y, as follows:

[0033] On the b-b line: reference point coordinate is Y-4.9, intersection with the d-d line is Y-212.3;

[0034] Intersection of section I with each line: b-b line is Y+1.3, line is Y-43.6, line is Y-94.8, line is Y-148.4, line is Y-205.3, d-d line is Y-206.3;

[0035] Intersection of section II with each line: b-b line is Y+6.6, line is Y-17.5, line is Y-64.4, line is Y-114, line is Y-168.5, d-d line is Y-197.8;

[0036] Intersection of section III with each line: b-b line is Y+12.7, line is Y-8.7, line is Y-34.6, line is Y-80.5, line is Y-130.6, d-d line is Y-188.9;

[0037] Intersection of section IV with each line: b-b line is Y+19.9, line is Y-3.5, line is Y-46.3, line is Y-92.8, line is Y-146.2, d-d line is Y-179.1;

[0038] Intersection of section V with each line: b-b line is Y+27.6, line is Y-11.6, line is Y-53.1, line is Y-100.9, Line Y- 160.7, d-d line Y- 168.5;

[0039] Intersection of section VI with lines: b-b line Y+ 35.4, Line Y+ 18.9, Line Y- 18.1, Line Y- 58.4, Line Y- 106.4, d-d line Y- 156.5;

[0040] Intersection of section VII with lines: b-b line Y+ 44.3, Line Y+ 15.1, Line Y- 21.7, Line Y- 62.4, Line Y- 111.8, d-d line Y- 143.5;

[0041] Intersection of section VIII with lines: b-b line Y+ 54, Line Y+ 49.4, Line Y+ 14.4, Line Y- 23, Line Y- 65.3, Line Y- 118.1, d-d line Y- 130.6;

[0042] Intersection of section IX with lines: b-b line Y+ 66.4, Line Y+ 56.3, Line Y+ 17.2, Line Y- 22.2, Line Y- 67.4, d-d line Y- 118.5;

[0043] Intersection of section X with lines: Line Y- 11.5, Line Y- 68, d-d line Y- 105.7;

[0044] Intersection of section XI with lines: Line Y- 59.2, d-d line Y- 92.1;

[0045] Intersection of section XII with lines: d-d line Y- 75.2;

[0046] The coordinate units are mm.

[0047] Preferably, each intersection coordinate parameter tolerance range is .

[0048] Preferably, a first half-guide vane and a second half-guide vane are further arranged at the outlet side of the impeller, each of the first half-guide vane and the second half-guide vane having five stationary blades.

[0049] Preferably, a gap between the upper shaft sleeve and the upper rubber bearing is , and a gap between the lower shaft sleeve and the lower rubber bearing is .

[0050] The beneficial effects of the present application are:

[0051] 1. Efficiency is significantly improved, and energy consumption is reduced:

[0052] By optimizing the design of the mixed-flow impeller (three moving blades) and the guide vane (five stationary blades), excellent hydraulic performance is achieved. Under the premise of meeting the large flow and variable head requirements of the ship cooling system, the overall efficiency is greatly improved.

[0053] The comparison data is clear: under the core test working condition (flow rate Qst / h), the efficiency of the water pump is improved from 61.6% of the traditional axial flow pump to 74.3%, with an absolute improvement of about 12.7% and a relative improvement of about 20.6%.

[0054] Within the commonly used wide flow range (0.85Qs~1.3Qs) of ships, the efficiency of the mixed-flow pump is superior to that of the axial flow pump, especially in the commonly used working condition area, which means that the energy consumption of the ship power system can be significantly saved in long-term operation.

[0055] 2. Running stability and working condition adaptability are enhanced:

[0056] The unique blade profile design enables the water pump to better adapt to various flow-head matching working conditions, meeting the changing cooling needs of modern ship power systems.

[0057] The pressure distribution of the mixed-flow pump is more uniform, avoiding the "hump" curve problem that is prone to occur in axial flow pumps, and the operation is more stable, with stronger resistance to working condition fluctuations.

[0058] 3. Key structural innovation reduces internal loss:

[0059] Innovative wedge-shaped groove design at the top of the impeller: five evenly distributed wedge-shaped grooves with a specific angle (15° in longitudinal section, 10° in bevel angle) are arranged on the surface of the annular chamber at the conical top of the impeller. This structure can form a counter-pressure balance area when the impeller rotates, effectively suppressing the backflow of the working medium (sea water) through the gap between the impeller and the pump body, thereby significantly reducing the volume loss, which is one of the key structural factors for efficiency improvement.

[0060] This groove design also has the effects of reducing vibration and noise and improving cavitation performance, improving the stability and reliability of the water pump operation.

[0061] 4. Performance verification is reliable, and the technology is mature:

[0062] Through detailed numerical simulation (CFD) and physical test comparison, the effectiveness of the design method is verified (the calculation error is only 4.9%).

[0063] The simulation cloud comparison shows that the pressure difference (ΔP) of the pressure surface and the suction surface of the mixed-flow pump impeller is greater than that of the axial-flow pump, indicating that its working capacity is stronger and the energy conversion is more sufficient.

[0064] The net positive suction head is calculated to be much higher than the safety requirement, ensuring the anti-cavitation ability for long-term operation in the ship environment.

[0065] 5. The structure design takes into account the durability and maintenance convenience:

[0066] The sacrificial anode protection design is adopted: the anticorrosion shield is made of Q235A material, and the rest of the metal parts are made of duplex steel. Through the principle of potential difference, the shield is preferentially corroded, effectively protecting the core body of the water pump from seawater corrosion and prolonging the overall service life.

[0067] Precise gap control: the gap of the key rotating parts (such as the upper and lower shaft sleeves and the rubber bushing) is precisely controlled within the range of 0.5-0.7mm, which not only ensures the effectiveness of water lubrication, but also ensures the stability and low wear of operation.

[0068] Modular assembly design (such as two half guides), which is convenient for installation, maintenance and maintenance.

[0069] 6. Comprehensive performance optimization, more suitable for ship environment:

[0070] Under the premise of not significantly increasing the size of the pump body, the comprehensive improvement of flow and head is realized, solving the limitation of the compact space of the ship engine room.

[0071] The advantages of efficiency improvement, vibration and noise reduction, and corrosion resistance enhancement work together to significantly improve the overall technology maturity and application range of the water pump, making it very suitable as a high-efficiency and reliable cooling equipment for modern high-power ship power systems.

[0072] In summary, through the innovative mixed-flow impeller profile design, unique impeller top groove structure, reasonable material and corrosion prevention design, and precise assembly process, a high-efficiency, stable, reliable, durable and adaptable large-flow marine circulating water pump is successfully developed, effectively solving the problems of low efficiency, poor working condition adaptability and insufficient stability of traditional axial-flow pumps in ship applications. BRIEF DESCRIPTION OF DRAWINGS

[0073] Figure 1 is a front view of the mixed-flow circulating water pump;

[0074] Figure 2 This is a front view of the impeller;

[0075] Figure 3 This is a blade profile diagram (front view);

[0076] Figure 4 This is a blade profile diagram (top view);

[0077] Figure 5 This is a schematic diagram of the impeller groove structure;

[0078] Figure 6 yes Figure 5 HH sectional view;

[0079] Figure 7 yes Figure 6 GG cross-sectional view;

[0080] Figure 8 The existing axial flow pump has a flow rate of 0.85. Pressure distribution at time, Figure 8 (a) is a contour map of the pressure surface of the axial flow pump impeller. Figure 8 (b) is a contour map of the suction surface of the axial flow pump impeller;

[0081] Figure 9 The present invention relates to a diagonal flow circulating water pump with a flow rate of 0.85. Pressure distribution at time, Figure 9 (a) is a contour map of the impeller pressure surface of a mixed-flow circulating water pump. Figure 9 (b) is a cloud diagram of the suction surface of the impeller of the mixed-flow circulating water pump;

[0082] Figure 10 The existing axial flow pump has a flow rate of 0.92. Pressure distribution at time, Figure 10 (a) is a contour map of the pressure surface of the axial flow pump impeller. Figure 10 (b) is a contour map of the suction surface of the axial flow pump impeller;

[0083] Figure 11 The present invention relates to a diagonal flow circulating water pump with a flow rate of 0.92. Pressure distribution at time, Figure 11 (a) is a contour map of the impeller pressure surface of a mixed-flow circulating water pump. Figure 11 (b) is a cloud diagram of the suction surface of the impeller of the mixed-flow circulating water pump;

[0084] Figure 12 The existing axial flow pump is operating at its rated flow rate. Pressure distribution at time, Figure 12 (a) is a contour map of the pressure surface of the axial flow pump impeller. Figure 12 (b) is a contour map of the suction surface of the axial flow pump impeller;

[0085] Figure 13 is the pressure distribution of the present invention of the mixed flow circulating water pump when the flow rate is 1.07Q , and Figure 13 (a) is the pressure surface cloud chart of the mixed flow circulating water pump impeller, and Figure 13 (b) is the suction surface cloud chart of the mixed flow circulating water pump impeller.

[0086] Figure 14 is the pressure distribution of the existing axial flow pump when the flow rate is 1.07Q , and Figure 14 (a) is the pressure surface cloud chart of the axial flow pump impeller, and Figure 14 (b) is the suction surface cloud chart of the axial flow pump impeller.

[0087] Figure 15 is the pressure distribution of the present invention of the mixed flow circulating water pump when the flow rate is 1.07Q , and Figure 15 (a) is the pressure surface cloud chart of the mixed flow circulating water pump impeller, and Figure 15 (b) is the suction surface cloud chart of the mixed flow circulating water pump impeller.

[0088] Figure 16 is the pressure distribution of the existing axial flow pump when the flow rate is 1.14Q , and Figure 16 (a) is the pressure surface cloud chart of the axial flow pump impeller, and Figure 16 (b) is the suction surface cloud chart of the axial flow pump impeller.

[0089] Figure 17 is the pressure distribution of the present invention of the mixed flow circulating water pump when the flow rate is 1.14Q , and Figure 17 (a) is the pressure surface cloud chart of the mixed flow circulating water pump impeller, and Figure 17 (b) is the suction surface cloud chart of the mixed flow circulating water pump impeller.

[0090] Figure 18 is the pressure distribution of the existing axial flow pump when the flow rate is 1.21Q , and Figure 18 (a) is the pressure surface cloud chart of the axial flow pump impeller, and Figure 18 (b) is the suction surface cloud chart of the axial flow pump impeller.

[0091] Figure 19 is the pressure distribution of the present invention of the mixed flow circulating water pump when the flow rate is 1.21Q , and Figure 19 (a) is the pressure surface cloud chart of the mixed flow circulating water pump impeller, and Figure 19 (b) is the suction surface cloud chart of the mixed flow circulating water pump impeller.

[0092] Figure 20 is the pressure distribution of the existing axial flow pump when the flow rate is 1.3Q Pressure distribution at time, Figure 20 (a) is a contour map of the pressure surface of the axial flow pump impeller. Figure 20 (b) is a contour map of the suction surface of the axial flow pump impeller;

[0093] Figure 21 The present invention relates to a diagonal flow circulating water pump with a flow rate of 1.3... Pressure distribution at time, Figure 21 (a) is a contour map of the impeller pressure surface of a mixed-flow circulating water pump. Figure 21 (b) is a cloud diagram of the suction surface of the impeller of the mixed-flow circulating water pump.

[0094] 1. Pump shaft; 2. Set screw; 3. Upper shaft sleeve; 4. Upper rubber bearing; 5. Upper pump cover; 6. First half guide vane; 7. Anti-corrosion protective plate; 8. Anti-corrosion protective plate bolt; 9. Lower rubber bearing; 10. Bearing cover; 11. Lower pump cover; 12. Washer; 13. Inlet bellows; 14. Impeller chamber; 15. Outlet bellows; 16. Upper pump body; 17. Second half guide vane; 18. Lower shaft sleeve; 19. Lower pump body; 20. Pump body fastening bolt; 21. Impeller; 22. Impeller nut; 23. Wedge groove.

[0095] A1, Impeller centerline; A2, Hub edge; A3, Blade. Detailed Implementation

[0096] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0097] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0098] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0099] Specific Implementation Method 1: The following is combined with... Figures 1 to 21 This embodiment describes a high-flow-rate diagonal-flow circulating water pump for cooling the power system of large ships. For example... Figure 1 As shown, the water pump has a vertical structure and mainly includes a rotor assembly, a stator assembly, a sealing and lubrication system, and inlet and outlet connection components.

[0100] 1. Assembly of rotor components

[0101] The rotor assembly is the core working part of the water pump, and its assembly steps are as follows:

[0102] a. Insert the impeller 21 into the designated shoulder position of the pump shaft 1, ensuring that the keyway of the impeller is aligned with the flat key of the pump shaft.

[0103] b. Tighten the impeller nut 22 to the specified torque using a special torque wrench, ensuring that the impeller does not rotate relative to the pump shaft.

[0104] c. After heating the upper shaft sleeve 3 and the lower shaft sleeve 18, they are hot-fitted to the corresponding shoulder positions on the upper part of the pump shaft. After the shaft sleeves cool down, an interference fit is formed.

[0105] d. In the threaded hole at the top of the upper shaft sleeve 3, screw in the retaining screw 2 and tighten it. This retaining screw not only prevents the shaft sleeve from loosening, but the smooth boss formed by its head also improves the flow field, effectively preventing local cavitation and reducing direct seawater erosion, thereby protecting the pump shaft 1.

[0106] 2. Assembly of the stator component (pump housing)

[0107] The stator component constitutes the flow channel and support structure of the water pump, and the assembly sequence is from bottom to top:

[0108] a. Inlet assembly: Connect the inlet bellows 13 and the impeller chamber 14 through the flange and bolt gasket assembly to form a sealed connection, forming the inlet flow channel.

[0109] b. Lower chamber assembly: Connect the lower pump body 19 and the lower pump cover 11 through the pump body fastening bolt 20 and the sealing gasket to form a closed chamber. This chamber is used to accommodate the lower part of the impeller and guide the water flow.

[0110] c. Bearing and guide installation: In the bearing seat of the lower pump cover 11, install the lower rubber bushing 9 and press it tightly with the bearing cover 10. Then, align the first half guide 6 and the second half guide 17, position them by the stopper in the inner hole of the guides, and then fasten the two half guides together with bolts. The 5 static blades in the guide play a role in flow guiding and rectification.

[0111] d. Upper chamber assembly: Connect the upper pump body 16 and the upper pump cover 5, which have been assembled with the rotor, to the lower pump body 19 and the lower pump cover 11 through the bolt gasket assembly to form a complete pump body closed flow channel. The outlet bellows 15 is installed on the outlet flange of the upper pump body 16.

[0112] e. Upper bearing and seal installation: Install the upper rubber bushing 4 in the bearing seat of the upper pump cover 5. Hoist the entire assembled rotor component and place it into the pump housing, with the pump shaft 1 passing through the upper and lower rubber bushings. It is crucial to ensure that the radial clearance between the lower shaft sleeve 18 and the lower rubber bushing 9 is within the range of 0.2-0.3 mm, and the radial clearance between the upper shaft sleeve 3 and the upper rubber bushing 4 is within the range of 0.1-0.2 mm. ​The gap range ensures effective formation of water lubrication film, both supporting the rotor and minimizing resistance.

[0113] f. Top sealing: The packing water seal ring composed of two halves is assembled on the upper shaft sleeve 3, and the sealing packing is filled, finally compressed by the packing gland and fastened with the pump body by bolts, completing the axial positioning and sealing.

[0114] 3. Anti-corrosion design implementation

[0115] In addition to the anti-corrosion guard 7, all metal parts of the water pump (including the pump body, shaft sleeve, pump body fastening bolts 20, anti-corrosion guard bolts 8, etc.) are made of the same type of duplex stainless steel material (such as 2205). The anti-corrosion guard 7 is separately made of Q235A carbon steel and installed on the inner wall of the pump body in the easily corroded part through the anti-corrosion guard bolts 8. In the seawater electrolyte environment, the Q235A material has a more negative potential than the duplex steel, and as a sacrificial anode, it is preferentially corroded, thereby forming effective electrochemical protection for the duplex steel pump body as the cathode, greatly extending the overall service life of the water pump.

[0116] 4. Key design parameters of core working components

[0117] a. Blade profile design: The efficiency improvement of the present application is first derived from the optimized blade profile. The impeller is designed with 3 spatially twisted blades. As shown in FIGS. Figure 2 , 3 4, the profile is defined by a series of spatial cross sections. With the center of the impeller as the spatial coordinate origin, and with the blade inlet edge (the leading edge on the shroud side) and the hub edge as the reference, the spatial curved surface shapes of the blade working surface (pressure surface) and the back surface (suction surface) can be uniquely determined by the precise size data given in Table 1 and Table 2. This profile design ensures that the fluid obtains uniform and smooth acceleration and pressurization within the impeller, suitable for a wide flow range of 0.85 to 1.3 .

[0118] The impeller 21 has 3 blades;

[0119] The spatial coordinate system for defining the blade profile has the center of the impeller as the origin;

[0120] The leading edge of the blade working surface on the shroud side is defined as the a-a line and serves as the inlet edge, and the trailing edge on the hub side is defined as the c-c line and serves as the outlet edge;

[0121] The leading edge of the blade back surface on the shroud side is defined as the b-b line and serves as the inlet edge, and the trailing edge on the hub side is defined as the d-d line and serves as the outlet edge;

[0122] The radial distance of the nearest point on the a-a line to the origin is taken as the reference distance Y;

[0123] On the working surface of the blade, a set of characteristic lines extending from line aa to line cc are defined and labeled as line A, line B, line C, line D, line E, line F, line G, line H, line I, and line J in sequence.

[0124] On the back of the blade, a set of characteristic lines extending from the bb line to the dd line are defined accordingly, and are labeled as follows: Wire, Wire, Wire, Wire, Wire, Wire, Wire, Wire, Wire, Wire;

[0125] Define the plane centered at the origin and passing through the water inlet side where the aa line and bb line are located as the 0° reference plane;

[0126] Twelve radial sections are defined, centered on the origin, surrounding the impeller axis and spaced at specific angles from the 0° reference plane. These twelve radial sections are sequentially labeled as section I, section II, section III, section IV, section V, section VI, section VII, section VIII, section IX, section X, section XI, and section XII from the hub side to the rim side.

[0127] The profile of the blade working surface is defined by the coordinates of the intersection points of each characteristic profile (line A to line J) and each radial section (I to XII). The radial coordinate values ​​of each intersection point are referenced to the reference distance Y, as shown in Table 1.

[0128] Table 1 Blade Working Surface Profile Design Table

[0129]

[0130] The profile on the back of the blade is formed by the back. Line to The coordinates of the intersection points of the characteristic line of the line with the twelve radial sections on the back side are defined, and the radial coordinate values ​​of each intersection point are referenced to the reference distance Y. The specific values ​​are shown in Table 2:

[0131] Table 2 Blade Back Profile Design Table

[0132]

[0133] b. Impeller top wedge-shaped groove design: such as Figure 5 As shown, five wedge-shaped grooves 23 are evenly distributed circumferentially on the surface of the annular chamber at the conical top of the impeller 21. The longitudinal section angle α of the groove is 15°, and the angle β between the groove's hypotenuse and the vertical direction is 10°. The width L of the groove ranges from... The shortest distance H of the longitudinal section is in the range of The specific value is determined according to the model and size of the pump. The core role of the groove is that when the impeller rotates at high speed, at the gap between the top of the impeller and the pump shell, the groove can form a local reverse pressure field, balance the pressure difference between the main flow and the gap flow, and thus significantly inhibit the leakage of the high-pressure side fluid to the low-pressure side (i.e. volume loss), which is another key to efficiency improvement. At the same time, this structure can smooth the gap vortex, play the effect of reducing vibration and noise, and improve the inlet condition, improve the cavitation performance.

[0134] 5. Working process of the water pump

[0135] After starting the water pump, the driving motor drives the pump shaft 1 and the impeller 21 to rotate at high speed. The seawater flows from the inlet bellows 13 into the impeller chamber 14. The three moving blades of the impeller 21 work on the seawater, increasing its pressure and kinetic energy. The high-speed rotating water flow out of the impeller enters the chamber composed of the lower pump body 19 and the lower pump cover 11, and is rectified by the five stationary blades of the first half-guide 6 and the second half-guide 17, converting part of the rotational kinetic energy into pressure energy and making the water flow axial. Subsequently, the water flow enters the chamber surrounded by the upper pump cover 5 and the upper pump body 16, and is further rectified by the internal guide plate, forming a stable velocity circulation, and finally discharged from the outlet bellows 15 to the ship cooling system.

[0136] During the whole process, the lower rubber bushing 9 and the upper rubber bushing 4 are self-lubricated by seawater to support the stable operation of the pump shaft.

[0137] 6. Performance verification

[0138] In order to verify the performance advantages of the inclined flow circulating water pump provided by the present application, especially the significant improvement in efficiency compared with the traditional axial flow pump, numerical simulation and physical test are combined to verify the performance advantages. The specific process, results and analysis are as follows:

[0139] (1) Theoretical basis for efficiency calculation

[0140] Pump efficiency is the core indicator to measure its performance, defined as the ratio of effective power to shaft power , and the calculation formula is:

[0141]

[0142] Among them, the shaft power is the mechanical power input to the pump shaft by the motor.

[0143] The calculation formula of effective power is:

[0144] In the formula, For the density of the transported liquid, acceleration due to gravity

[0145] Fluid volumetric flow rate

[0146] The head (m) is determined by the total energy difference between the pump inlet and outlet, and is calculated using the following formula:

[0147]

[0148] For pump outlet pressure, The pump inlet pressure, The height of the pump outlet. For pump inlet height, For fluid outlet velocity, This represents the fluid inlet velocity.

[0149] (2) Numerical simulation and pressure distribution analysis

[0150] Compared to the mixed-flow pump of the present invention and a conventional axial-flow pump with the same parameters, in the typical operating range of a ship's cooling system (0.85... Up to 1.3 , Computational fluid dynamics (CFD) simulations were performed at seven operating points within the rated flow rate, and pressure distribution contour maps of the impeller surface were obtained (see...). Figures 8 to 21 ).

[0151] Key analytical conclusions:

[0152] a. Pressure distribution uniformity: Comparison Figure 8 and Figure 9 (0.85) Operating conditions) Figure 12 and Figure 13 ( Operating conditions) Figure 20 and Figure 21 (1.3) From the cloud diagrams of all corresponding operating conditions (such as operating conditions), it can be seen that the impeller of the mixed flow pump ( Figure 9 , 13 The pressure gradients on the pressure and suction surfaces of the axial flow pump (Figure 21, right side (b)) are more gradual and evenly distributed. Figure 8 , 12 The pressure distribution in Figure 20 (a) on the left shows obvious unevenness, especially with a high-pressure concentration area near the water outlet of the blade.

[0153] b. Work Capacity Comparison: The pressure distribution directly reflects the impeller's ability to perform work on the fluid. Under rated operating conditions... For example, Figure 12 With Figure 13 , the average pressure difference between the pressure surface and the suction surface of the axial flow pump impeller is calculated by extracting data , while the average pressure difference of the mixed flow pump is The working pressure difference of the mixed flow pump is about 35% higher than that of the axial flow pump, which indicates that the mixed flow pump can transmit more energy to the fluid, i.e. obtain higher lift H or higher efficiency when the same H is required, under the same flow rate and rotational speed.

[0154] c. Indirect verification of cavitation performance: In all mixed flow pump cloud maps, the low pressure area range at the inlet of the blade suction surface is relatively smaller and the pressure value is relatively higher, which is consistent with the excellent (much higher than the safety requirement) NPSH calculation result described in the “summary of the invention”, indicating that it has better anti-cavitation performance.

[0155] (3) Efficiency comparison calculation results

[0156] Based on the lift and shaft power of the pump under each working condition obtained by CFD simulation, the efficiency of the mixed flow pump and the axial flow pump in the entire working condition range is calculated according to the above efficiency formula, and the results are summarized in Table 3:

[0157] Table 3 Pump efficiency table at each flow rate

[0158]

[0159] (4) Efficiency advantage analysis

[0160] In the entire verified wide flow range ( ), the efficiency of the mixed flow pump of the present application is higher than that of the conventional axial flow pump.

[0161] At the rated design working condition point ( ), the efficiency is improved most significantly, from 61.6% of the axial flow pump to 74.3%, with an absolute efficiency improvement of 12.7 percentage points, and a relative improvement of more than 20%.

[0162] The high efficiency area of the mixed flow pump is wider. In the flow range of , its efficiency always remains above 72%, and the highest reaches 76.5%, which is very suitable for the needs of variable working condition operation of the ship power system.

[0163] (5) Physical test verification and error analysis

[0164] In order to verify the accuracy of the numerical simulation, a principle prototype is manufactured according to the present embodiment, and performance test is carried out on a standard test bench.

[0165] Under the rated working condition , the measured efficiency of the pump is 78.13%.

[0166] The absolute error is 3.83 percentage points, and the relative error is about 4.9% compared with the CFD simulation result (74.3%). The error is within the reasonable range of engineering CFD simulation, which proves that the model, boundary conditions and calculation method used in the foregoing numerical simulation are reliable and effective, and the simulation result is reliable for the conclusion of performance trend and comparison.

[0167] Conclusion:

[0168] Through the flow field analysis of the pressure cloud map shown in Figures 8 to 21 The efficiency calculation based on rigorous theoretical formula and physical test verification fully prove that the "marine large-flow mixed-flow circulating water pump" provided by the application realizes a leap in the core efficiency index compared with the traditional axial flow pump. At the same time, it also shows significant advantages in pressure distribution uniformity, work ability and wide working condition adaptability, and fully meets the technical requirements of modern large-scale ship power systems for high-efficiency and reliable cooling water pumps.

[0169] Although the application is described herein with reference to particular embodiments, it will be understood that these examples are merely illustrative of the principles and applications of the present application. It will therefore be appreciated that numerous modifications can be made to the illustrative embodiments and that other arrangements can be devised without departing from the spirit and scope of the present application as defined by the appended claims. It will be understood that different dependent claims and features described herein can be combined with each other in ways that differ from the original claims described. It will also be understood that features described in connection with individual embodiments can be used in other described embodiments.

Claims

1. A marine high-flow-rate diagonal-flow circulating water pump, comprising a pump shaft (1), an impeller (21) mounted on the pump shaft (1), and a pump body assembly covering the impeller (21), the pump body assembly forming a flow channel from an inlet bellows (13) to an outlet bellows (15); an upper shaft sleeve (3) and a lower shaft sleeve (18) are mounted on the pump shaft (1), and are respectively supported on the pump body assembly by an upper rubber bearing (4) and a lower rubber bearing (9); Its features are, The impeller (21) has five evenly distributed wedge-shaped grooves (23) on the surface of the annular chamber at the top, and the longitudinal section angle of the wedge-shaped grooves (23) is... The hypotenuse of the wedge-shaped groove (23) forms an angle with the vertical direction. The inclination angle, the groove width L of the wedge groove (23) is 10-15mm, and the shortest distance H of the longitudinal section of the wedge groove (23) is 3-30mm; The impeller (21) has 3 blades; The spatial coordinate system used to define the blade profile has the impeller center as its origin; The leading edge of the blade working surface on the rim side is defined as line aa, and the trailing edge on the hub side is defined as line cc. Define the leading edge of the blade on the rim side as the bb line and the trailing edge on the hub side as the dd line; The radial distance from the nearest point to the origin on line aa is taken as the reference distance Y; On the working surface of the blade, a set of characteristic lines extending from line aa to line cc are defined and labeled as line A, line B, line C, line D, line E, line F, line G, line H, line I, and line J in sequence. On the back of the blade, a set of characteristic lines extending from the bb line to the dd line are defined accordingly, and are labeled as follows: Wire, Wire, Wire, Wire, Wire, Wire, Wire, Wire, Wire, Wire; Define the plane centered at the origin and passing through the water inlet edge of the blade as the 0° reference plane; Twelve radial sections are defined, centered on the origin, surrounding the impeller axis and angularly spaced from the 0° reference plane. These twelve radial sections are sequentially labeled as section I, section II, section III, section IV, section V, section VI, section VII, section VIII, section IX, section X, section XI, and section XII from the hub side to the rim side. The profile of the blade working surface is defined by the coordinates of the intersection points of each characteristic profile and each radial section. The radial coordinate values ​​of each intersection point are referenced to the reference distance Y, and the specific values ​​are as follows: On line aa: the reference point coordinates are Y, the intersection with line A is Y-52.1, the intersection with line B is Y-104.2, the intersection with line C is Y-156.3, and the corresponding point on cc is Y-206.6; Intersection I with each line: line aa is Y+7.8, line A is Y-15.4, line B is Y-66, line C is Y-116.7, line D is Y-167.5, and line cc is Y-196.

3. Intersection II with each line: line aa is Y+13.8, line A is Y+13.3, line C is Y-81.7, line D is Y-129.1, line E is Y-176.7, and line cc is Y-185.3; Intersections of section III with each line: line aa is Y+21, line C is Y-47.2, line D is Y-92.7, line E is Y-138.1, and line cc is Y-174.3; Intersections of section IV with each line: line aa is Y+28.3, line C is Y-14, line D is Y-57.2, line E is Y-100.6, line F is Y-143.8, and line cc is Y-162.

7. Intersection V with each line: line aa is Y+36.3, line C is Y+19.3, line D is Y-22.6, line E is Y-64.5, line F is Y-106.4, line G is Y-148.4, and line cc is Y-151.3; Intersections of section VI with each line: line aa is Y+43.6, line D is Y+8.8, line E is Y-30.8, line F is Y-70.2, line G is Y-109.7, and line cc is Y-139.1; Intersections of section VII with each line: line aa is Y+53, line D is Y+44.9, line E is Y+6.4, line F is Y-32.1, line G is Y-70.7, line H is Y-109.2, and line cc is Y-126.

4. Intersection VIII with each line: line aa is Y+53.1, line E is Y+40.8, line F is Y+3.2, line G is Y-34.4, line H is Y-72, line I is Y-109.7, and line cc is Y-114.3; Intersections of section IX with each line: line aa is Y+73.8, line F is Y+45.3, line G is Y+6.4, line H is Y-32.4, line I is Y-71.4, and line cc is Y-102.

2. Intersections of section X with each line: H line is Y+16.3, I line is Y-28.6, J line is Y-73.7, and cc line is Y-91.4; Intersection of section XI with each line: the cc line is Y-82.1; Intersection of section XII with each line: line cc is Y-73.3; The profile on the back of the blade is formed by the back. Line to The coordinates of the intersection points of the characteristic line of the line with the twelve radial sections on the back side are defined, and the radial coordinate values ​​of each intersection point are referenced to the reference distance Y. The specific values ​​are as follows: On line bb: the reference point coordinates are Y-4.9, and the intersection with line dd is Y-212.3; Intersection of section I with each line: the intersection of line bb is Y+1.

3. The line is Y-43.

6. The line is Y-94.

8. The line is Y-148.

4. The line is Y-205.3, and the dd line is Y-206.3; Intersection of section II with each line: the intersection of line bb is Y+6.

6. The line is Y-17.

5. The line is Y-64.

4. The line is Y-114. The line is Y-168.5, and the dd line is Y-197.8; Intersection of section III with each line: line bb is at Y+12.

7. The line is Y-8.

7. The line is Y-34.

6. The line is Y-80.

5. The line is Y-130.6, and the dd line is Y-188.9; Intersection of section IV with each line: the intersection of line bb is Y+19.

9. The line is Y-3.

5. The line is Y-46.

3. The line is Y-92.

8. The line is Y-146.2, and the dd line is Y-179.1; Intersection of section V with each line: The intersection of line bb is Y+27.

6. The line is Y-11.

6. The line is Y-53.

1. The line is Y-100.

9. The line is Y-160.7, and the dd line is Y-168.5; Intersection of section VI with each line: the intersection of line bb is Y+35.

4. The line is Y+18.

9. The line is Y-18.

1. The line is Y-58.

4. The line is Y-106.4, and the dd line is Y-156.5; Intersection of section VII with each line: The intersection of line bb is Y+44.

3. The line is Y+15.

1. The line is Y-21.

7. The line is Y-62.

4. The line is Y-111.8, and the dd line is Y-143.5; Intersection of section VIII with each line: the intersection of line bb is Y+54. The line is Y+49.

4. The line is Y+14.

4. The line is Y-23. The line is Y-65.

3. The line is Y-118.1, and the dd line is Y-130.6; Intersection of section IX with each line: the intersection of line bb is Y+66.

4. The line is Y+56.

3. The line is Y+17.

2. The line is Y-22.

2. The line is Y-67.4, and the dd line is Y-118.5; Intersections of section X with each line: The line is Y-11.

5. The line is Y-68, and the dd line is Y-105.7; Intersections of section XI with each line: The line is Y-59.2, and the dd line is Y-92.1; Intersection of section XII with each line: the dd line is Y-75.2; The coordinate unit is mm.

2. The marine high-flow-rate diagonal-flow circulating water pump according to claim 1, characterized in that, The tolerance range of the coordinate parameters of each intersection point is: .

3. The marine high-flow-rate diagonal-flow circulating water pump according to claim 1, characterized in that, It also includes a first semi-guide (6) and a second semi-guide (17) disposed on the outlet side of the impeller (21), each of the first semi-guide (6) and the second semi-guide (17) having 5 stationary blades.

4. The marine high-flow-rate oblique-flow circulating water pump according to claim 1, characterized in that, The gap between the upper bushing (3) and the upper rubber bearing (4) is The gap between the lower bushing (18) and the lower rubber bearing (9) is .

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