A multi-stage centrifugal pump

Abstract

The present application relates to centrifugal pump technical field, especially to a kind of multistage centrifugal pump, including the pump body of being equipped with central shaft, pump body is connected by two half shells, gradually changing cavity, three ring grooves and two long cavities of shunt backwater are set in pump body;Pump body is provided with the booster unit corresponding to three ring grooves and two long cavities of shunt backwater by gradually changing cavity, booster unit is composed of three expansion tooling and two shunt tooling, three expansion tooling are located in three ring grooves so that water flow obtains centrifugal force three times.This application thus further realizes deceleration, deceleration by layer;Heat dissipation cavity and assembly cavity are set in the front and rear sides of pump body, which are distributed around ring groove, utilize heat conduction plate and aluminum foil piece to conduct the high temperature heat generated by central shaft rotation, then utilize cotton long-term absorption cooling liquid to soak aluminum foil piece in heat dissipation cavity, so that cooling liquid volatilizes and discharges on the heat absorption aluminum foil piece, to realize the heat dissipation protection of pump body.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centrifugal pumps, in particular to a multi-stage centrifugal pump. BACKGROUND

[0002] A centrifugal pump is a kind of rotary power pump using a rotating impeller to increase fluid velocity, and is the most commonly used fluid conveying machine in process engineering. Under the action of centrifugal force, liquid is thrown to the edge of the impeller to form a high-speed water flow, and the high-speed water flow is guided to the water outlet through the guide effect of the pump shell, thereby realizing the conveying of liquid. With the continuous increase of building height and the diversification of real production and life, the traditional single-stage centrifugal pump cannot meet the needs of higher-level water delivery.

[0003] Under the existing conditions, a multi-stage centrifugal pump as claimed in application No. CN202410242452.4 is usually adopted, which realizes the effect of pumping water into the inner cylinder through the interaction of the blocking door, the first impeller and the centrifugal wheel, and avoids the water filling link. However, the multi-stage and complex water delivery structure arranged by the pump shell and the inner cylinder can realize the range extension conveying to a certain extent, but it is easy to lead to the complication of the overall structure of the centrifugal pump, and the single form of the pressure increasing assembly mainly in the centrifugal wheel only realizes the range extension by the superposition of the number, which leads to the winding and changeable water flow path under the structure limitation, greatly increases the complexity of water flow movement, and easily causes the problem of internal blockage of the centrifugal pump due to water flow impurities, which is difficult to maintain. Like the multi-stage centrifugal pump as claimed in application No. CN202411088319.4, the water spraying mechanism is arranged inside the single-stage shell, a plurality of single-stage shells are arranged in series in the pump body shell, and the simultaneous operation of the water spraying mechanisms in the plurality of single-stage shells can simultaneously fill water in the multi-stage cavities of the multi-stage centrifugal pump. The efficient water filling mode reduces the influence of air binding phenomenon, but still realizes the single form driving of water flow by the superposition of the number, and the water flow in each stage is relatively stable, and the degree of deceleration is limited, so the effect of the subsequent turbine and volute on the deceleration and pressure increase of the water flow is also extremely limited, and it is difficult to effectively enable the water flow in the limited pump body space. The existing centrifugal pump still adopts the terminal heat dissipation measures similar to the traditional water pump, and with the increase of the number of single-stage water driving structures, the heat in the pump body is generated more quickly, and the heat dissipation fan at the terminal position of the centrifugal pump cannot effectively dissipate heat for the long-structured and multi-stage water driving components, and the high temperature load also seriously limits the play of the water driving effect. SUMMARY

[0004] The purpose of the present application is to solve the problem of insufficient water flow pressure caused by the limitation of water flow movement of the single structure form centrifugal pump in the prior art, and to propose a multi-stage centrifugal pump.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0006] A multi-stage centrifugal pump, comprising a pump body provided with a central shaft, the pump body being composed of two half shells connected together, and a gradually changing cavity, three ring grooves and two long cavities for water return being formed in the pump body;

[0007] The gradually changing cavity of the pump body is provided with a pressurizing part corresponding to the three ring grooves and the two long cavities for water return, the pressurizing part being composed of three expansion tools and two distribution tools, the three expansion tools being respectively located in the three ring grooves so that the water flow obtains centrifugal force three times, and the two distribution tools respectively corresponding to the two long cavities for water return so that the water flow is distributed and slowed down twice.

[0008] The pump body is provided with a heat dissipation part through the ring grooves, the heat dissipation part being distributed along the gradually changing cavity and comprising a heat dissipation cavity and a container cavity filled with cooling liquid, the heat dissipation cavity being used to reduce the temperature of the pump body to 30-65℃ by absorbing and consuming heat through the evaporation of the cooling liquid.

[0009] The gradually changing cavity is a left-narrow-right-wide horn structure, the three ring grooves are coaxially distributed along the gradually changing cavity from left to right, and the two long cavities for water return are equidistantly distributed between each adjacent two ring grooves.

[0010] The expansion tool comprises a volute shell fixedly sleeved on the ring groove and movably sleeved on the central shaft, and further comprises a turbine keyed on the central shaft and movably sleeved in the volute shell, a water inlet opening being formed in the left side wall of the volute shell, and a water outlet opening being formed in the right side wall of the volute shell.

[0011] The distribution tool comprises a swing baffle plate installed on the outlet side wall of the volute shell through a pin shaft, and a ring-shaped elastic cross-shaped buckle is slidably arranged on the central shaft and used to movably pull the swing baffle plate.

[0012] Preferably, the two half shells are symmetrically arranged front to back, and a sealing strip is fixedly embedded in the opening position of each half shell.

[0013] Preferably, the diameters of the three ring grooves gradually increase from left to right, and the diameter of the right ring groove is 1.25 times that of the left ring groove.

[0014] Preferably, the water inlet opening and the water outlet opening are both radially formed, the water inlet opening spirally pointing to the central part of the turbine, and the water outlet opening spirally pointing to the edge part of the volute shell.

[0015] Preferably, the swing baffle plate is located between the water outlet opening and the long cavity for water return.

[0016] Preferably, the heat dissipation part comprises a heat conduction plate fixedly arranged in the ring groove, the heat conduction plate being fixedly connected with an aluminum foil piece located in the heat dissipation cavity, and a cotton strip being arranged in the container cavity and extending into the heat dissipation cavity.

[0017] Preferably, the cotton wick is immersed in the cooling liquid, and the aluminum foil piece contacts the cooling liquid located in the heat dissipation cavity.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] 1、The present application utilizes two half shells to form a pump body, and simultaneously forms a gradually changing cavity structure with a left narrow part and a right wide part, so that the water flow in the gradually changing cavity meets the mass conservation law and the continuity equation, and simultaneously meets the Bernoulli principle, and the water flow speed is slowed down in the gradually changing cavity, so as to increase the movement path of the water flow in the pump body, and to provide space and time conditions for water flow pressurization.

[0020] 2、The present application sets three ring grooves with gradually increasing sizes in the gradually changing cavity, sets three volutes with gradually increasing sizes by using the three ring grooves, sets a turbine driven to rotate by a central shaft by using the three volutes, drives the water flow to rotate and diffuse in a centrifugal manner to obtain high-speed kinetic energy, and simultaneously forms a diffuser passage by using the volutes, so that the water flow obtains pressure energy by reducing the flow speed, and the three-stage pressurization part can make the water flow realize layer-by-layer pressurization and energy assignment, and realizes pressurized delivery in the energy form conversion process.

[0021] 3、The present application movably installs a tension and closing baffle plate on the front two volutes, and simultaneously sets a long water return cavity corresponding to the tension and closing baffle plate in the gradually changing cavity, and utilizes the separated reverse impact main flow under the action of the Tesla valve principle to reduce the water flow speed, so as to further realize the deceleration effect, so that the water flow can be more concentrated in the rear volute, and layer-by-layer deceleration is realized.

[0022] 4、The present application sets heat dissipation cavities and assembly cavities distributed around the ring grooves in the front and rear sides of the pump body, utilizes a heat conduction plate and an aluminum foil piece to conduct the high-temperature heat generated by the rotation of the central shaft, and then utilizes a cotton wick to long-term absorb the cooling liquid to immerse the aluminum foil piece in the heat dissipation cavities, so that the cooling liquid volatilizes and discharges by absorbing the heat on the aluminum foil piece, so as to realize the heat dissipation protection of the pump body. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A structural schematic view of a multi-stage centrifugal pump is provided for the present application;

[0024] Figure 2 A bottom view of a multi-stage centrifugal pump is provided for the present application;

[0025] Figure 3 A front sectional view of a multi-stage centrifugal pump is provided for the present application;

[0026] Figure 4 An upper sectional view of two half shells of a multi-stage centrifugal pump is provided for the present application;

[0027] Figure 5 A front sectional view of a long water return cavity of a multi-stage centrifugal pump is provided for the present application;

[0028] Figure 6 A left view of the central shaft and the booster part of a multi-stage centrifugal pump according to the present application;

[0029] Figure 7 A right view of the central shaft and the booster part of a multi-stage centrifugal pump according to the present application;

[0030] Figure 8 A left view of the expansion tool and the flow distribution tool of a multi-stage centrifugal pump according to the present application;

[0031] Figure 9 A left view of the expansion tool and the flow distribution tool of a multi-stage centrifugal pump according to the present application;

[0032] Figure 10 A left front sectional view of the expansion tool and the flow distribution tool of a multi-stage centrifugal pump according to the present application;

[0033] Figure 11 A front sectional view of the heat dissipation part of a multi-stage centrifugal pump according to the present application;

[0034] Figure 12 A schematic diagram of a preferred embodiment of the volute of a multi-stage centrifugal pump according to the present application;

[0035] Figure 13 A schematic diagram of the water flow movement path of a preferred embodiment of the volute of a multi-stage centrifugal pump according to the present application;

[0036] Figure 14 A schematic diagram of the water flow movement speed variation of a preferred embodiment of the volute of a multi-stage centrifugal pump according to the present application.

[0037] In the drawings:

[0038] 1, pump body; 11, half shell; 12, gradual change cavity; 13, ring groove;

[0039] 14, flow distribution backwater long cavity; 141, coarse inlet section; 142, middle turning section; 143, fine outlet section;

[0040] 2, central shaft; 3, booster part;

[0041] 31, expansion tool; 311, volute; 312, water inlet passage; 313, water outlet passage; 314, turbine;

[0042] 32, flow distribution tool; 321, opening and closing baffle; 322, guide long hole; 323, annular elastic double-D buckle; 324, synchronous slider; 325, traction connecting rod;

[0043] 4, heat dissipation part; 41, heat dissipation cavity; 42, assembly cavity; 43, heat conduction plate; 44, aluminum foil; 45, cotton. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application.

[0045] Reference Figures 1-13 A multi-stage centrifugal pump comprises a pump body 1 provided with a central shaft 2, the pump body 1 is composed of two half shells 11 which are symmetrically arranged front and back, and the opening positions of the two half shells 11 are fixedly embedded with sealing strips, and the pump body 1 is provided with a tapered cavity 12, three ring grooves 13 and two long split water return cavities 14, the tapered cavity 12 is a left-narrow-right-wide horn structure, the three ring grooves 13 are coaxially distributed along the tapered cavity 12 from left to right, and the two long split water return cavities 14 are equidistantly distributed between each adjacent two ring grooves 13.

[0046] Specifically referring to the drawings Figure 1 -attached Figure 3 The pump body 1 is provided with a water inlet on the back side of the narrow end corresponding to the tapered cavity 12, and is provided with a water injection port on the front side, and is provided with a water outlet on the end corresponding to the wide end of the tapered cavity 12, and a proper amount of water flow is injected into the pump body 1 through the water injection port at the initial opening to serve as a drainage, so as to avoid the idling of the turbine 314. The water inlet is located on the left side of the first ring groove 13, and the water outlet is located on the right side of the third ring groove 13.

[0047] The left and right ends of the pump body 1 are opened through the tapered cavity 12, and adopt a counterbore structure, and the assembly connection and sealing of the left and right ends of the pump body 1 are realized through the pump cover with a central hole, on the one hand, the installation of the central shaft 2 is realized, and on the other hand, the right end of the pump body 1 is provided with a heat dissipation fan by using the central shaft 2, and the end of the central shaft 2 extending out of the left end of the pump body 1 is provided with a shaft coupling, so as to be connected with a driving motor, which is a commonly used prior art means for the pump body 1, and thus is not described in detail.

[0048] In some embodiments, the diameters of the three ring grooves 13 increase in sequence from left to right, and the diameter of the ring groove 13 on the right side is 1.25 times that of the ring groove 13 on the left side, the shape structure of the ring groove 13 is matched with the volute 311, and the left and right sides of the volute 311 are each connected with a clamping bolt structure embedded in the ring groove 13, so as to ensure the installation stability of the volute 311 in the ring groove 13.

[0049] Further, the two long split water return cavities 14 each adopt a left-narrow-right-wide horn structure, and the opening diameter of the long split water return cavity 14 on the right side is 1.25 times that of the long split water return cavity 14 on the left side. The long split water return cavity 14 comprises a coarse inlet section 141, a transfer section 142 and a fine outlet section 143.

[0050] The coarse inlet section 141 is obliquely arranged in the half shell 11 towards the right upper direction, and one end of the coarse inlet section 141 is communicated with the gradual change cavity 12. The water flow ejected from the volute 311 enters the wider gradual change cavity 12 in a divergent form, and the main flow still moves in a spiral path, while the branch flow enters the coarse inlet section 141 under the action of centrifugal force.

[0051] The middle turning section 142 is obliquely arranged in the half shell 11 towards the right lower direction, and one end of the middle turning section 142 is communicated with the other end of the coarse inlet section 141. The opening diameter of the middle turning section 142 is 0.75 times of the opening diameter of the coarse inlet section 141. Because the path channel of the middle turning section 142 gradually narrows, the speed of the branch flow is accelerated, and the branch flow enters the fine outlet section 143 under the turning action.

[0052] The fine outlet section 143 is obliquely arranged in the half shell 11 towards the left lower direction, and two ends of the fine outlet section 143 are respectively communicated with the other end of the middle turning section 142 and the gradual change cavity 12. The opening diameter of the fine outlet section 143 is 0.75 times of the opening diameter of the middle turning section 142. Because the path channel of the fine outlet section 143 gradually narrows, the speed of the branch flow is further accelerated, and when the branch flow enters the gradual change cavity 12, the branch flow impacts the main flow flowing to the right, that is, the branch flow acts on the main flow according to the principle of Tesla valve, so that the speed of the main flow is slowed down, and the main flow enters the next volute 311 located on the right side in a concentrated manner.

[0053] In some embodiments, the pump body 1 is provided with a booster 3 corresponding to the three annular grooves 13 and the two branch flow return long cavities 14 through the gradual change cavity 12. The booster 3 is composed of three expansion tools 31 and two branch tools 32.

[0054] Specifically, referring to the drawings in the specification Figure 3 , the drawings Figure 6 and the drawings Figure 7 , the three expansion tools 31 are respectively located in the three annular grooves 13 so that the water flow obtains centrifugal force three times. The expansion tool 31 includes a volute 311, a water inlet opening 312, a water outlet opening 313 and a turbine 314.

[0055] The number of volutes 311 is three. The three volutes 311 are respectively sleeved in the three annular grooves 13, and the three volutes are movably sleeved on the central shaft 2. The three volutes 311 are proportionally increased according to the three annular grooves 13, and the volume of the volute 311 on the right side is 1.25 times of the volume of the volute 311 on the left side. The number of turbines 314 is three. The three turbines 314 are all key-connected to the central shaft 2, and are movably sleeved in the three volutes 311. The three turbines 314 are proportionally increased according to the three volutes 311, and the volume of the turbine 314 on the right side is 1.25 times of the volume of the turbine 314 on the left side.

[0056] In combination with the effect of the volute 311 and the turbine 314, the water flow is energized by the impeller in the turbine 314, so that the water flow obtains the kinetic energy of high-speed movement in the process of being tended to the edge position of the volute 311; and after the water flow enters the volute 311, the flow rate is reduced due to the widening of the channel, so as to realize the conversion of kinetic energy into pressure energy.

[0057] In the above process, because three volutes 311 and three turbines 314 are arranged layer by layer, three different degrees of centrifugal force are applied to the water flow in the flow process, and at the same time, different volumes of volutes 311 are used to realize the speed reduction of the water flow on the basis of three different flow rates, and different degrees of pressure energy are obtained.

[0058] The water inlet opening 312 is arranged at the left side wall position of the volute 311, and the water flow is transported to the center position of the turbine 314 by the water inlet opening 312 with a concentration tendency, so as to facilitate the turbine 314 to add centrifugal force to the water flow entering the volute 311.

[0059] The water outlet opening 313 is arranged at the right side wall position of the volute 311, and the water flow in the center position has the centrifugal force effect of outward diffusion under the driving action of the turbine 314, so as to obtain a lower degree of flow rate.

[0060] Further explanation:

[0061] The water inlet opening 312 and the water outlet opening 313 are both radially arranged, the water inlet opening 312 spirally faces the center part of the turbine 314, and the water outlet opening 313 spirally faces the edge part of the volute 311, so that the water flow gradually obtains a lower degree of flow rate through three times of centrifugal force loading.

[0062] In some embodiments, the volute 311 is preferably a spiral structure, as shown in the drawings Figure 12 -attached Figure 13 The water inlet opening 312 is arranged in the left side wall of the volute 311 and faces the center position of the volute 311, so that the water flow converges towards the center part of the turbine 314, and the water outlet opening 313 is arranged at the edge position of the volute 311 and diverges towards the outside of the edge of the volute 311, and the water flow driven by the turbine 314 spreads from the water outlet opening 313.

[0063] Specifically referring to the drawings Figure 14 In the process of speed reduction and energy increase by the booster part 3, the flow rate of the water flow changes:

[0064] In the t1-t2 stage, the first expansion device 31 is used for acceleration;

[0065] In the t2-t3 stage, the first flow dividing device 32 is used for speed reduction;

[0066] In the t3-t4 stage, the water is accelerated by the second expansion device 31;

[0067] In the t4-t5 stage, the water is decelerated by the second flow dividing device 32;

[0068] In the t5-t6 stage, the water is accelerated by the third expansion device 31.

[0069] However, the acceleration in the t3-t4 stage is obviously lower than that in the t1-t2 stage, and the acceleration in the t5-t6 stage is obviously lower than that in the t3-t4 stage;

[0070] The deceleration in the t4-t5 stage is obviously higher than that in the t2-t3 stage.

[0071] Further, the inclined groove in the annular groove 13 corresponds to the inclined channel of the water outlet 313, and the water discharged from the volute 311 enters the gradual change cavity 12 through the inclined channel, so as to enter the next volute 311.

[0072] Specifically, referring to the drawings in the specification Figure 5 -attached Figure 10 The two flow dividing devices 32 correspond to the two flow dividing water return long cavities 14 respectively, so that the water flow is divided twice for deceleration. The flow dividing device 32 includes a closing and opening baffle 321, a guide long hole 322, a ring-shaped elastic hourglass-shaped buckle 323, a synchronous sliding block 324, and a traction connecting rod 325.

[0073] The closing and opening baffle 321 is installed on the right side wall of the volute 311 through a pin shaft, and corresponds to one end of the gradual change cavity 12 connected to the thin outlet section 143. The closing and opening baffle 321 has an L-shaped structure in cross section, which can intercept and decelerate the water flow flowing to the right to a certain extent, and can also diffuse the water flow movement path during the closing and opening process.

[0074] The guide long hole 322 is arranged in the central shaft 2.

[0075] The ring-shaped elastic hourglass-shaped buckle 323 is slidably sleeved on the central shaft 2 through the guide long hole 322. It should be noted that the ring-shaped elastic hourglass-shaped buckle 323 is composed of a strong spring and a ring buckle. The strong spring is fixedly arranged in the left end of the guide long hole 322, and elastically pulls the ring buckle which is slidably sleeved on the central shaft 2 in the guide long hole 322. Under the support and traction of the ring buckle, the closing and opening baffle 321 has a closing trend.

[0076] The synchronous slider 324 is slidingly installed on the annular elastic chain link 323, and the synchronous slider 324 rotates along the annular elastic chain link 323. During the rotation of the annular elastic chain link 323 driven by the central shaft 2, the opening and closing baffle 321 is always in a state of repeated opening and closing due to the centrifugal expansion tendency and the impact driving of the water flow. The annular elastic chain link 323 rotates in the forward and backward direction relative to the synchronous slider 324, and the synchronous slider 324 moves linearly in the left and right direction relative to the annular elastic chain link 323.

[0077] The traction connecting rod 325 is connected to the opening and closing baffle 321 and the synchronous slider 324 through a pin shaft.

[0078] In some embodiments, with reference to the description of the accompanying drawings Figure 1 , accompanying drawings Figure 2 , accompanying drawings Figure 4 and accompanying drawings Figure 11 , the pump body 1 is provided with a heat dissipation part 4 through the annular groove 13, and the heat dissipation part 4 is distributed along the tapered cavity 12. The heat dissipation cavity 41 cools the pump body 1 to 30-65℃ by absorbing and consuming heat through the evaporation of the cooling liquid. The heat dissipation part 4 includes the heat dissipation cavity 41, the storage cavity 42, the heat conduction plate 43, the aluminum foil 44, and the cotton strip 45.

[0079] The heat dissipation cavity 41 is formed in the half shell 11 around the annular groove 13, and an outlet extending out of the half shell 11 is formed at the upper end of the heat dissipation cavity 41.

[0080] The storage cavity 42 is formed in the half shell 11 around the heat dissipation cavity 41, and the storage cavity 42 is filled with a cooling liquid. The cooling liquid is preferably an ethylene glycol solution with a concentration of 3.56%-5.28%. The storage cavity 42 and the lower end of the heat dissipation cavity 41 are in one-way communication from bottom to top, and a liquid seepage passage is formed in the half shell 11 to connect the two.

[0081] The heat conduction plate 43 is fixedly arranged in the annular groove 13, and the aluminum foil 44 is fixedly connected to the heat conduction plate 43. The aluminum foil 44 is located in the heat dissipation cavity 41. The heat conduction plate 43 can not only conduct the high-temperature heat of the pump body 1, but also support the annular groove 13 in an arc structure to avoid deformation or leakage of the annular groove 13 in the half shell 11 under the long-term impact of the water flow.

[0082] The cotton strip 45 is immersed in the cooling liquid in the storage cavity 42, and the cotton strip 45 extends into the heat dissipation cavity 41. The aluminum foil 44 contacts the cooling liquid in the heat dissipation cavity 41. The cotton strip 45 absorbs and transports the cooling liquid from low to high, so that the cooling liquid can continuously supply the aluminum foil 44 in the heat dissipation cavity 41, and the aluminum foil 44 contacts the cooling liquid to further absorb its heat for evaporation, thereby achieving the effect of cooling and heat dissipation.

[0083] The baffle 321 is located between the water outlet 313 and the long water return cavity 14.

[0084] It should be noted that the specific model of the pump body 1 is determined according to the actual specifications of the device, and the specific selection calculation method adopts the existing technology in the art, so it is not described here.

[0085] The function principle of the present application can be described as follows:

[0086] A proper amount of water flow is injected into the left end of the gradual cavity 12 of the pump body 1 through the water inlet, and the center shaft 2 is rotated by the driving motor, and the three turbines 314 are synchronously rotated by the center shaft 2;

[0087] In this process:

[0088] The first turbine 314 sucks the water flow into the first volute 311, forming an adsorption of the external water flow, so that the external water flow enters the first volute 311 through the water inlet, and is dispersed and transported into the gradual cavity 12 by the first turbine 314, part of the water flow enters the coarse inlet section 141 of the first long water return cavity 14, is transported after turning by the middle turning section 142, is accelerated, and is then discharged through the fine outlet section 143, so as to impact the main water flow in the gradual cavity 12, so as to reduce the flow rate of the main water flow to form a water flow with V1;

[0089] The water flow with V1 enters the second volute 311 under the action of the second turbine 314, and then enters the wider gradual cavity 12 with the second turbine 314, part of the water flow enters the coarse inlet section 141 of the second long water return cavity 14, is transported after turning by the middle turning section 142, is accelerated, and is then discharged through the fine outlet section 143, so as to impact the main water flow in the gradual cavity 12, so as to reduce the flow rate of the main water flow to form a water flow with V2;

[0090] The water flow with V2 enters the third volute 311 under the action of the third turbine 314, and then enters the wider gradual cavity 12 with the third turbine 314, so as to increase the flow rate of the main water flow to form a water flow with V3;

[0091] The water flow with V3 is discharged from the pump body 1 through the drain to supply the water flow.

[0092] In this process, the rotational motion of the center shaft 2 causes frictional heat, the heat is conducted to the heat conduction plate 43 through the impact contact of the water flow and the volute 311, the heat is transmitted to the aluminum foil piece 44 by the heat conduction plate 43, the cotton strip 45 absorbs the cooling liquid in the assembly cavity 42 into the heat dissipation cavity 41, and the lower end of the aluminum foil piece 44 is immersed in the cooling liquid, the cooling liquid absorbs the heat of the aluminum foil piece 44 and evaporates, and is discharged from the outlet, so as to reduce the temperature of the pump body 1.

[0093] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical solution and inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A multistage centrifugal pump comprising a pump body (1) in which a central shaft (2) is mounted, the pump body (1) being composed of two half-shells (11) joined together, characterized in that, The pump body (1) is provided with a gradient cavity (12), three annular grooves (13) and two diversion return water long cavities (14). The pump body (1) is provided with a pressurization section (3) corresponding to three annular grooves (13) and two diversion return water long chambers (14) through a gradual change chamber (12). The pressurization section (3) is composed of three expansion fixtures (31) and two diversion fixtures (32). The three expansion fixtures (31) are located in the three annular grooves (13) respectively, so that the water flow receives centrifugal force three times. The two diversion fixtures (32) correspond to the two diversion return water long chambers (14) respectively, so that the water flow is diverted and decelerated twice. The pump body (1) is provided with a heat dissipation part (4) through the annular groove (13). The heat dissipation part (4) is distributed along the gradient cavity (12), and the heat dissipation part (4) includes a heat dissipation cavity (41) and a collection cavity (42) filled with coolant. The heat dissipation cavity (41) absorbs and consumes heat through the evaporation of coolant, thereby cooling the pump body (1) to 30-65℃. The gradient cavity (12) is a trumpet-shaped structure that is narrow on the left and wide on the right. The three annular grooves (13) are coaxially distributed from left to right along the gradient cavity (12). The two diversion return water long cavities (14) are equidistantly distributed between each two adjacent annular grooves (13). The expansion fixture (31) includes a volute (311) fixedly fitted in the annular groove (13) and movably fitted on the central shaft (2), and the expansion fixture (31) also includes a turbine (314) keyed to the central shaft (2) and movably fitted inside the volute (311). A water inlet (312) is provided on the left side wall of the volute (311), and a water outlet (313) is provided on the right side wall of the volute (311). The diversion tool (32) includes a diversion baffle (321) with a pin mounted on the outlet side wall of the volute (311), and an annular elastic H-shaped buckle (323) for moving and pulling the diversion baffle (321) is slidably provided on the central shaft (2).

2. A multi-stage centrifugal pump according to claim 1, characterized in that The two half-shells (11) are arranged symmetrically front to back, and the openings of the two half-shells (11) are fixedly fitted with sealing strips.

3. A multi-stage centrifugal pump according to claim 2, characterized in that The diameters of the three annular grooves (13) increase sequentially from left to right, with the diameter of the right annular groove (13) being 1.25 times the diameter of the left annular groove (13).

4. A multi-stage centrifugal pump according to claim 3, characterized in that Both the water inlet (312) and the water outlet (313) are radially opened. The water inlet (312) spirals toward the center of the turbine (314), and the water outlet (313) spirals toward the edge of the volute (311).

5. A multi-stage centrifugal pump according to claim 4, characterized in that The baffle plate (321) is located between the water outlet (313) and the diversion return water elongated cavity (14).

6. A multi-stage centrifugal pump according to claim 5, characterized in that The heat dissipation part (4) includes a heat-conducting plate (43) fixedly disposed in the annular groove (13), and the heat-conducting plate (43) is fixedly connected to an aluminum foil piece (44) located in the heat dissipation cavity (41). A cotton strip (45) extending into the heat dissipation cavity (41) is disposed in the container cavity (42).

7. A multi-stage centrifugal pump according to claim 6, characterized in that The cotton strip (45) is immersed in the coolant, and the aluminum foil (44) is in contact with the coolant located in the heat dissipation cavity (41).

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