Multi-stage pump with higher stability and reliability

Abstract

The invention relates to the technical field of multi-stage pumps, and particularly discloses a multi-stage pump with higher stability and reliability. The pump shafts are arranged in the pump body at intervals; the impeller assembly is installed on the pump shaft and located between the pump body and the pump shaft; the first bearing box is installed at one end of the pump body, and one end of the pump shaft extends out of the pump body and is rotationally connected to a bearing in the first bearing box; the lifting and measuring part is connected between the pump body and the first bearing box, and the lifting and measuring part is used for lifting the first bearing box; the buffering pieces are arranged between the impeller assembly and the inner wall of the pump body and on one side of the bearing correspondingly, and the buffering pieces are used for buffering the impeller assembly and the bearing; the two sides of the impeller assembly and the inner wall of the pump body form a flow blocking cavity and a cover plate cavity correspondingly, and the hydraulic pressure generated by a medium in the flow blocking cavity to the impeller assembly and the hydraulic pressure generated by a medium in the cover plate cavity to the impeller assembly are balanced. According to the multi-stage pump with higher stability and reliability, the running stability, reliability and safety are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-stage pumps, in particular to a multi-stage pump with higher stability and reliability. BACKGROUND

[0002] The radial area of the front cover plate of the impeller of the multi-stage pump is smaller than that of the rear cover plate, and is equal to the radial area of the suction inlet of the impeller. When the multi-stage pump is running, the pressure at the suction inlet of the impeller is smaller than that at the front and rear cover plates of the impeller, so that an axial force is generated. The multi-stage pump uses multiple impellers in series to stack the lift of the impellers to achieve high lift, which causes the axial force generated during the operation of the multi-stage pump to be larger. At present, the multi-stage pump uses a balance disc mechanism and an impeller balance hole to balance the axial force. When the balance disc mechanism balances the axial force, it causes the rotor of the multi-stage pump to move left and right, and cannot completely balance the axial force. When the balance hole balances the axial force, the high-pressure liquid at the rear cover plate of the impeller enters the inlet side flow passage of the impeller through the balance hole in the form of a jet. The high-pressure liquid collides with the fluid flowing into the impeller inlet, causing disturbance, and the main liquid flowing into the impeller generates vortexes and local flow separation, so that the energy conversion efficiency of the liquid and the impeller is not high.

[0003] After long-term use, the bearing box stop, the middle segment stop, the guide stop, the water inlet section and the water outlet section of the multi-stage pump will rust, causing the fitting size of the bearing box and the parts to be out of tolerance, causing the rotor components of the multi-stage pump to sag during operation. At present, there is no lifting system to lift the rotor components as a whole upward, so as to eliminate the eccentricity of the rotor and the parts, which will cause the rotating components and the non-rotating components of the multi-stage pump to rub and be damaged, and cause the vibration and noise of the multi-stage pump to increase, causing the damage of the inducer, the damage of the port ring, the damage of the balance drum, etc. At the same time, after the rotor sags, the impeller deviates from the center of the guide vane of the pump, so that the flow passage of the impeller and the guide vane is not in the best matching state. When the impeller performs hydraulic energy conversion, pressure fluctuations and pressure vortices occur, causing fluctuation excitation, vortex excitation and inter-stage cavitation, which causes damage to the pump, and seriously reduces the operation stability, reliability and safety of the pump.

[0004] When the working flow of the multi-stage pump is less than or greater than the design rated flow, for example: changes in the working pressure of the pipe network system, changes in the demand flow of the output terminal, changes in the frequency of the power grid system, changes in the lift of the pump inlet pipeline system, loss of speed or overspeed of the driving system, etc., pressure fluctuations will occur, causing changes in the axial force, which will cause the rotor components of the multi-stage pump to move axially, causing safety hazards in the operation of the multi-stage pump.

[0005] Therefore, the technical solution of the present application is needed to solve the above problems. SUMMARY

[0006] The application aims to provide a multi-stage pump with higher stability and reliability, and improve the stability, reliability and safety of operation.

[0007] To achieve the above-mentioned purpose, the application provides a multi-stage pump with higher stability and reliability, comprising: a pump body; a pump shaft arranged in the pump body; a impeller assembly installed on the pump shaft and located between the pump body and the pump shaft; a first bearing box installed on one end of the pump body, and one end of the pump shaft extending out of the pump body and connected to a bearing in the first bearing box; a lifting element connected between the pump body and the first bearing box, configured to lift the first bearing box; and a buffer element arranged between the impeller assembly and the inner wall of the pump body and on one side of the bearing, respectively, configured to buffer the impeller assembly and the bearing; wherein the two sides of the impeller assembly and the inner wall of the pump body form a resistance flow cavity and a cover plate cavity, respectively, and when the impeller assembly rotates, the hydraulic pressure generated by the medium in the resistance flow cavity on the impeller assembly and the hydraulic pressure generated by the medium in the cover plate cavity on the impeller assembly reach balance.

[0008] In some embodiments, the pump body comprises: a water inlet section, and a water outlet corresponding to the inducer; a water outlet section, having a pressure relief cavity; a balance pipe, having two ends respectively communicating with the water inlet section and the pressure relief cavity; a middle section assembly, having two ends respectively communicating with the water inlet section and the water outlet section, and the impeller assembly is arranged on the inner wall of the middle section assembly; a balance drum installed on the pump shaft; and a balance ring installed on the water outlet section, and the balance ring is arranged in the outer wall of the balance drum in a spaced manner; The impeller assembly includes a first impeller, a second impeller, and a third impeller, the third impeller is close to the water outlet section, the cover plate cavity corresponding to the third impeller is communicated with the pressure relief cavity through the gap between the balance drum and the balance ring; the middle section assembly has a flow relief cavity corresponding to the side wall of the first impeller and the side wall of the second impeller, the flow relief cavity and the cover plate cavity are separated by a friction ring and a friction surface, the flow relief cavity is communicated with the suction inlet of the first impeller and the suction inlet of the second impeller, the first impeller and the second impeller form a flow relief passage with the pump shaft, the flow relief cavity is communicated with the suction inlet of the first impeller through the flow relief passage, the third impeller, the balance ring, the outer friction ring, the inner friction ring, the balance drum and the pump shaft form a balance cavity, the balance cavity and the cover plate cavity are separated by the outer friction ring and the inner friction ring, the balance cavity is communicated with the pressure relief cavity through the gap between the balance drum and the balance ring.

[0009] In some embodiments, the middle section assembly includes: a first middle section having an inner wall with a first flow passage surface configured to form a first flow resistance cavity with an outer wall of the impeller assembly; a second middle section mounted at an outlet of the first middle section, the second middle section having a second pressurized water flow passage and a second suction flow passage in communication, the second pressurized water flow passage being communicated with the first middle section; and a third middle section mounted at an outlet of the second middle section, the third middle section having a third pressurized water flow passage, a third suction flow passage, and a fourth pressurized water flow passage in communication, the third pressurized water flow passage being communicated with the second suction flow passage; wherein the second pressurized water flow passage, the third pressurized water flow passage, and the fourth pressurized water flow passage are configured to convert fluid kinetic energy into pressure energy, and the second suction flow passage and the third suction flow passage are configured to eliminate residual circulation of fluid; The second middle section is provided with multiple and sequentially connected second middle sections, the second middle section includes a second shell, a second guide vane, a second positive guide vane and a second reverse guide vane, the second guide vane is provided in the second shell, the second positive guide vane and the second reverse guide vane are connected between the second guide vane and the second shell, the second shell, the second positive guide vane and the second guide vane form the second water pressure flow channel, the second shell, the second reverse guide vane and the second guide vane form the second suction flow channel, the inner wall of the second shell has a second flow channel surface, the second flow channel surface and the impeller assembly form a second resistance flow cavity, the second guide vane close to the side wall of the first middle section has a second spring mounting groove; the third middle section includes a third shell, a third guide vane, a third positive guide vane and a third reverse guide vane, the third guide vane is provided in the third shell, the third positive guide vane and the third reverse guide vane are connected between the third guide vane and the third shell, the third shell, the third positive guide vane and the third guide vane form the third water pressure flow channel, the third shell, the third reverse guide vane and the third guide vane form the third suction flow channel, the third middle section includes a fourth positive guide vane and a reverse guide vane, the reverse guide vane is provided on the side of the third shell away from the third reverse guide vane, the reverse guide vane is connected with the third shell through the fourth positive guide vane, the third shell, the fourth positive guide vane and the reverse guide vane form a fourth water pressure flow channel, the inner wall of the third shell has a third flow channel surface, the third flow channel surface and the impeller assembly form a third resistance flow cavity, the third guide vane close to the side wall of the second middle section has a third spring mounting groove.

[0010] In some embodiments, a stabilizing rod is included, and the water inlet section, the middle section assembly and the water outlet section are connected through the stabilizing rod.

[0011] In some embodiments, the first bearing box has a first boss, the first boss is installed in the first positioning groove, the first boss has a first mounting threaded hole, and the first mounting threaded hole is arranged above the first positioning counterbore. The multi-stage pump includes: The first heat exchange seat has a first positioning groove and a first positioning counterbore arranged at the bottom of the first positioning groove. The second first heat exchange seat has a second positioning groove and a second positioning counterbore arranged at the bottom of the second positioning groove. The second bearing box has a second boss, the second boss is installed in the second positioning groove, the second boss has a second mounting threaded hole, and the second mounting threaded hole is arranged above the second positioning counterbore. The lifting amount piece includes: A first lift bolt is threadedly connected to the first mounting threaded hole, and a bottom of the first lift bolt abuts against the first positioning counterbore. A second lift bolt is threadedly connected to the second mounting threaded hole, and a bottom of the second lift bolt abuts against the second positioning counterbore. Wherein, the first lift bolt is screwed to lift the first bearing housing, and the second lift bolt is screwed to lift the second bearing housing, and the first bearing housing and the second bearing housing are configured to mount a pump shaft.

[0012] In some embodiments, the first boss has a first mounting counterbore disposed above the first mounting threaded hole, a head of the first lift bolt is located in the first mounting counterbore, the second boss has a second mounting counterbore disposed above the second mounting threaded hole, and a head of the second lift bolt is located in the second mounting counterbore. The lift piece comprises: The first boss has a first locking threaded hole disposed above the first mounting counterbore, a first locking nut is threadedly connected to the first locking threaded hole, and abuts against the head of the first lift bolt. A first stop nut is threadedly connected to the first stop threaded hole, and is located above the first locking nut. A first stop washer is disposed in the first stop threaded hole, the first stop washer is located between the first locking nut and the first stop nut, the first boss has a first stop groove passing through the first stop threaded hole, one end of the first stop washer horizontally extends out of the first stop groove, and is bent downward to fit against a side wall of the first boss away from the first positioning groove. The second boss has a second locking threaded hole disposed above the second mounting counterbore, a second locking nut is threadedly connected to the second locking threaded hole, and abuts against the head of the second lift bolt. A second stop nut is threadedly connected to the second stop threaded hole, and is located above the second locking nut, and a second stop washer is disposed in the second stop threaded hole, the second stop washer is located between the second locking nut and the second stop nut, the second boss has a second stop groove passing through the second stop threaded hole, one end of the second stop washer horizontally extends out of the second stop groove, and is bent downward to fit against a side wall of the second boss away from the second positioning groove.

[0013] In some embodiments, the pump body has a guide vane, a side wall of the guide vane has a first mounting groove, the impeller assembly close to the side wall of the guide vane has a friction surface, an inner wall of the first bearing housing has a second mounting groove, the bearing is disposed in the second mounting groove, and the buffer piece comprises: a first spring disposed in the first mounting slot; a friction ring disposed in the first mounting slot and connected with the spring, the other side of the friction ring extending out of the first mounting slot and abutting against the friction surface; and a second spring disposed in the second mounting slot, one end of the second spring abutting against the bearing; wherein the bearing is mounted on the outer circumferential wall of the pump shaft, and one end of the second spring abuts against the bearing.

[0014] In some embodiments, the first spring and the second spring are both corrugated springs, the bearing is an angular contact ball bearing, the side wall of the guide vane has two first mounting slots, the two first mounting slots are respectively located at the upper part and the lower part of the friction ring, the axial direction of the friction ring coincides with the axial direction of the impeller, the compression stroke of the first spring is a, and the thickness of the friction ring extending out of the first mounting slot when the first spring is not under stress is b, and a < b.

[0015] In some embodiments, the outer circumferential wall of the pump body is sleeved with a cylinder, and a first heat exchange cavity is formed between the cylinder and the pump body, the first heat exchange cavity is configured to input or output a heat exchange medium; The multi-stage pump comprises: a first heat exchange seat mounted on the side of the first bearing box away from the pump body, the pump shaft being rotatably mounted on the first heat exchange seat, the first heat exchange seat having a second heat exchange cavity, the second heat exchange cavity being configured to input or output a heat exchange medium; a second heat exchange seat mounted on one end of the pump body, the pump shaft being rotatably mounted on the second heat exchange seat, the second heat exchange seat having a third heat exchange cavity, the third heat exchange cavity being configured to input or output a heat exchange medium; and a third heat exchange seat mounted on the other end of the pump body, the pump shaft being rotatably mounted on the third heat exchange seat, the third heat exchange seat having a fourth heat exchange cavity, the fourth heat exchange cavity being configured to input or output a heat exchange medium.

[0016] In some embodiments, a vibration sensor and a plurality of temperature sensors are included, the vibration sensor is mounted on the first bearing box, and the plurality of temperature sensors are respectively mounted on the first heat exchange cavity, the second heat exchange cavity, the third heat exchange cavity and the fourth heat exchange cavity.

[0017] The application provides a multi-stage pump with higher stability and reliability, which has the beneficial effect that compared with the prior art, the pump shaft is arranged in the pump body, the impeller assembly is arranged between the pump body and the pump shaft, the first bearing box is arranged at one end of the pump body, one end of the pump shaft extends out of the pump body and is rotationally connected to the bearing in the first bearing box, the lifting piece is arranged between the pump body and the first bearing box and is configured to lift the first bearing box, the buffer piece is arranged between the impeller assembly and the inner wall of the pump body and on one side of the bearing, the buffer piece is configured to buffer the impeller assembly and the bearing, the two sides of the impeller assembly and the inner wall of the pump body form the flow resistance cavity and the cover plate cavity respectively, and the hydraulic pressure generated by the medium in the flow resistance cavity on the impeller assembly and the hydraulic pressure generated by the medium in the cover plate cavity on the impeller assembly reach balance when the impeller assembly rotates. In this way, the balance effect of the axial force can be improved by balancing the impeller assembly through the flow resistance cavity and the cover plate cavity, the operation safety of the multi-stage pump is ensured, the concentricity of the rotor part can be adjusted by lifting the first bearing box through the lifting piece and installing the pump shaft in the first bearing box, the operation safety and reliability are ensured, the axial movement of the rotor part can be eliminated by buffering through the cooperation of the first spring and the second spring when the axial force changes during the operation of the multi-stage pump, and the operation stability, reliability and safety are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic view of the axial cross-sectional structure of the multi-stage pump of the embodiment.

[0019] Figure 2 is a left view of the multi-stage pump of the embodiment.

[0020] Figure 3 is a schematic view of the water inlet section of the multi-stage pump of the embodiment.

[0021] Figure 4 is a schematic view of the water outlet section of the multi-stage pump of the embodiment.

[0022] Figure 5 is a schematic view of the first middle section of the multi-stage pump of the embodiment.

[0023] Figure 6 is a schematic view of the second middle section of the multi-stage pump of the embodiment.

[0024] Figure 7 is a schematic view of the third middle section of the multi-stage pump of the embodiment.

[0025] Figure 8 is an enlarged schematic view of the inducer chamber of the multi-stage pump of the embodiment.

[0026] Figure 9Schematic diagram of the second heat exchange seat of the multistage pump in this embodiment.

[0027] Figure 10 Schematic diagram of the third heat exchange seat of the multistage pump in this embodiment.

[0028] Figure 11 It is an enlarged schematic diagram of the second bearing box of the multi-stage pump of this embodiment.

[0029] Figure 12 It is an enlarged schematic diagram of the first bearing box of the multi-stage pump of this embodiment.

[0030] Figure 13 It is an enlarged schematic diagram of the balance ring of the multi-stage pump of this embodiment.

[0031] Figure 14 It is an enlarged schematic diagram of the stabilizing bar of the multi-stage pump of this embodiment.

[0032] Figure 15 yes Figure 1 Enlarged schematic diagram of point A in the middle.

[0033] Figure 16 yes Figure 1 Enlarged schematic diagram of point B in the middle.

[0034] Figure 17 yes Figure 1 Enlarged schematic diagram of point C in the middle.

[0035] Figure 18 yes Figure 1 Enlarged schematic diagram of point D in the middle.

[0036] Figure 19 yes Figure 1 Enlarged schematic diagram of point E in the middle.

[0037] Figure 20 It is an enlarged schematic diagram of the coordination between the stabilizing bar and the first stabilizing bar mounting position of the multi-stage pump of this embodiment.

[0038] In the figure: 1, water inlet section; 2, ninth temperature sensor; 3, eighth liquid outlet pipe; 4, eighth liquid inlet pipe; 5, eighth regulating valve; 6, left heat exchange cavity; 7, tenth temperature sensor; 8, ninth liquid outlet pipe; 9, second heat exchange seat; 10, cooling hole; 11, pump shaft; 12, second bearing box; 13, tenth liquid outlet pipe; 14, ninth liquid inlet pipe; 15, eleventh temperature sensor; 16, ninth regulating valve; 17, second bearing heat exchange cavity; 18, left mechanical seal; 19, fourteenth temperature sensor; 20, tenth liquid inlet pipe; 21, eleventh liquid outlet pipe; 22, tenth regulating valve; 23, left heat exchanger; 24, inducer chamber; 25, first impeller; 26, first middle section; 27, first middle section heat exchange cavity; 28, eleventh regulating valve; 29, first partition plate; 30, second middle section; 31, cylinder; 32, stabilizer lever; 33, first middle section heat exchange cavity; 34, second partition plate; 35, second middle section heat exchange cavity; 36, second impeller; 37, balance pipe; 38, third partition plate; 39, last middle section heat exchange cavity; 40, third middle section; 41, third impeller; 42, second pressure sensor; 43, balance ring; 44, balance drum; 45, water outlet section; 46, right heat exchanger; 47, twelfth regulating valve; 48, twelfth liquid outlet pipe; 49, eleventh liquid inlet pipe; 50, third regulating valve; 51, fifteenth temperature sensor; 52, right mechanical seal; 53, first bearing box; 54, first corrugated spring; 55, first liquid inlet pipe; 56, first regulating valve; 57, liquid outlet main pipe; 58, liquid inlet main pipe; 59, first bearing box heat exchange cavity; 60, first temperature sensor; 61, first liquid outlet pipe; 62, second liquid inlet pipe; 63, second regulating valve; 64, third temperature sensor; 65, second liquid outlet pipe; 66, third heat exchange seat; 67, right heat exchange cavity; 68, fourth temperature sensor; 69, third liquid outlet pipe; 70, third liquid inlet pipe; 71, angular contact ball bearing; 72, fifth temperature sensor; 73, fourth liquid outlet pipe; 74, fourth liquid inlet pipe; 75, fourth regulating valve; 76, sixth temperature sensor; 77, fifth liquid outlet pipe; 78, fifth liquid inlet pipe; 79, fifth regulating valve; 80, seventh temperature sensor; 81, sixth liquid outlet pipe; 82, sixth liquid inlet pipe; 83, sixth regulating valve; 84, eighth temperature sensor; 85, seventh liquid outlet pipe; 86, seventh liquid inlet pipe; 87, seventh regulating valve; 88, first stabilizer lever mounting position; 89, second stabilizer lever mounting position; 90, third stabilizer lever mounting position; 91, first flow channel inclined surface; 92, fourth stabilizer lever mounting position; 93, first anti-guide vane; 94, first flow channel circular arc surface; 95, first spring mounting position; 96, first flow channel arc surface; 97, fifth stabilizer lever mounting position; 98, second anti-guide vane; 99, second flow channel circular arc surface; 100, second spring mounting position; 101, second flow channel arc surface; 102, third flow channel circular arc surface; 103, second flow channel inclined surface; 104, first positioning counterbore; 105, first positioning groove.106, second positioning slot; 107, second positioning counterbore; 108, pressure relief seat; 109, pressure relief cavity; 110, first mounting thread; 111, first boss; 112, first mounting counterbore; 113, first stop thread; 114, first stop slot; 115, second mounting thread; 116, second mounting counterbore; 117, second stop slot; 118, second stop thread; 119, second boss; 120, mouth ring slot; 121, second upper arc surface; 122, second lower arc surface; 123, first lifting bolt; 124, first locking nut; 125, first stop washer; 126, first stop nut; 127, first mouth ring; 128, flow channel surface; 129, first-stage flow resistance cavity; 130, first-stage medium flow resistance; 131, first friction surface; 132, first friction ring; 133, first wave spring; 134, flow resistance ring; 135, first flow relief cavity; 136, first flow relief hole; 137, second flow relief cavity; 138, second friction surface; 139, second friction ring; 140, second wave spring; 141, medium flow state; 142, secondary-stage flow resistance cavity; 143, secondary-stage medium flow resistance; 145, second flow relief hole; 146, third flow channel arc surface; 147, final-stage medium flow resistance; 148, final-stage flow resistance cavity; 149, outer friction ring; 150, balance cavity; 151, inner friction ring; 153, first positive flow guide vane; 154, second positive flow guide vane; 155, third positive flow guide vane; 156, second lifting bolt; 157, second locking nut; 158, second stop washer; 159, second stop nut; 160, first upper arc surface; 161, first lower arc surface; 162, mouth ring friction surface; 163, first heat exchange seat; 164, rotor heat exchange cavity; 165, first liquid inlet; 166, first liquid outlet; 167, second liquid outlet; 168, second liquid inlet; 169, resistance separation plate; 170, first guide vane; 171, first suction flow channel; 172, second guide vane; 173, reverse guide vane; 174, second suction flow channel; 175, second impeller cover plate cavity; 176, third impeller cover plate cavity; 177, first water press flow channel; 178, second water press flow channel; 179, third water press flow channel; 180, inducer; 181, degassing pipe; 182, first vibration sensor; 183, second vibration sensor; 184, thirteenth temperature sensor; 185, third vibration sensor; 186, first pressure sensor; 187, fourth vibration sensor; 188, sixteenth temperature sensor; 189, seventeenth temperature sensor; 190, third pressure sensor; 191, fifth vibration sensor; 192, sixth vibration sensor; 193, twelfth temperature sensor; 194, second temperature sensor; 195, thirteenth regulating valve; 196, first sliding bearing; 197, second sliding bearing; 198, base; 199, exhaust pipe; 200, eighteenth temperature sensor; 201, nineteenth temperature sensor; 202, first probe mounting position;203, second probe mounting position; a, first included angle; b, second included angle; c, third included angle; d, fourth included angle; e, fifth included angle; f, sixth included angle; g, seventh included angle; h, eighth included angle. DETAILED DESCRIPTION

[0039] 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.

[0040] It should be understood that, in the description of the present application, the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. The terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated, that is, the features with "first", "second" can explicitly or implicitly include one or more of the features. In addition, unless otherwise stated, the meaning of "multiple" is two or more.

[0041] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict between them.

[0042] As Figures 1-20As shown, the multi-stage pump with higher stability and reliability of some embodiments of the present application comprises: a pump body, an inducer 180, a first impeller 25, a second impeller 36, a third impeller 41, a second bearing box 12, a first bearing box 53, an inducer chamber 24, a second heat exchange seat 9, a third heat exchange seat 66, a pressure relief seat 108, a pump shaft 11, a cylinder 31, a first partition plate 29, a second partition plate 34, a third partition plate 38, a blocking plate 169, a left mechanical seal 18, a right mechanical seal 52, a left heat exchanger 23, a right heat exchanger 46, a stabilizing lever 32, a first heat exchange seat 163, a liquid inlet main pipe 58, a liquid outlet main pipe 57, a first liquid inlet pipe 55, a second liquid inlet pipe 62, a third liquid inlet pipe 70, a fourth liquid inlet pipe 74, a fifth liquid inlet pipe 78, a sixth liquid inlet pipe 82, a seventh liquid inlet pipe 86, an eighth liquid inlet pipe 4, a ninth liquid inlet pipe 14, a tenth liquid inlet pipe 20, an eleventh liquid inlet pipe 49, a first liquid outlet pipe 61, a second liquid outlet pipe 65, a third liquid outlet pipe 69, a fourth liquid outlet pipe 73, a fifth liquid outlet pipe 77, a sixth liquid outlet pipe 81, a seventh liquid outlet pipe 85, an eighth liquid outlet pipe 3, a ninth liquid outlet pipe 8, a tenth liquid outlet pipe 13, an eleventh liquid outlet pipe 21, a twelfth liquid outlet pipe 48, a first temperature sensor 60, a second temperature sensor 194, a third temperature sensor 64, a fourth temperature sensor 68, a fifth temperature sensor 72, a sixth temperature sensor 76, a seventh temperature sensor 80, an eighth temperature sensor 84, a ninth temperature sensor 2, a tenth temperature sensor 7, an eleventh temperature sensor 15, a twelfth temperature sensor 193, a thirteenth temperature sensor 184, a fourteenth temperature sensor 19, a fifteenth temperature sensor 51, a sixteenth temperature sensor 188, a seventeenth temperature sensor 189, an eighteenth temperature sensor 200, a nineteenth temperature sensor 201, a first pressure sensor 186, a second pressure sensor 42, a third pressure sensor 190, a first regulating valve 56, a second regulating valve 63, a third regulating valve 50, a fourth regulating valve 75, a fifth regulating valve 79, a sixth regulating valve 83, a seventh regulating valve 87, an eighth regulating valve 5, a ninth regulating valve 16, a tenth regulating valve 22, an eleventh regulating valve 28, a twelfth regulating valve 47, a thirteenth regulating valve 195, an angular contact ball bearing 71, a left mechanical seal 18, a right mechanical seal 52, a first lifting bolt 123, a second lifting bolt 156, a first locking nut 124, a second locking nut 157, a first stop washer 125, a second stop washer 158, a first stop nut 126, a second stop nut 159, a balance pipe 37, a first sliding bearing 196, a second sliding bearing 197, a first vibration sensor 182, a second vibration sensor 183, a third vibration sensor 185, a fourth vibration sensor 187, a fifth vibration sensor 191, a sixth vibration sensor 192, a base 198, a first port ring 127, a first friction ring 132, a second friction ring 139, a first bellows spring 133, a second bellows spring 140, a third bellows spring 54, a flow blocking ring 134, a second port ring 144,Outer race 149, inner race 151, degassing pipe 181 and exhaust pipe 199. Pump body includes: water inlet section 1, water outlet section 45, first middle section 26, second middle section 30, third middle section 40, balance drum 44 and balance ring 43.

[0043] As shown in Figure 3 and 20 , the first stable pole mounting position 88 is provided on the water inlet section 1, the first stable pole mounting position 88 is provided at the top of the water inlet section 1, the first probe mounting position 202 is provided on the outer circle of the flange of the water inlet section 1, the first stable pole mounting position 88 is a rhombic hole, the rhombic hole is provided with two first upper arc surfaces 160 and two first lower arc surfaces 161, the number of the first stable pole mounting position 88 is ≥1, the sixth included angle of the two first upper arc surfaces 160 is f, the angle value of f is 30°-60°, the eighth included angle of the two first lower arc surfaces 161 is h, the angle value of h is 30°-60°, the angle value of f is equal to the angle value of h, the included angle of the first upper arc surface 160 and the first lower arc surface 161 is respectively the fifth included angle e and the seventh included angle g, the angle value of e is 120°-150°, the angle value of g is 120°-150°, the angle value of e is equal to the angle value of g.

[0044] As shown in Figure 4 , the second stable pole mounting position 89 is provided on the water outlet section 45, the second stable pole mounting position 89 is provided at the top of the water outlet section 45, the second probe mounting position 203 is provided on the outer circle of the flange of the water outlet section 45, the number and geometric parameter characteristics of the second stable pole mounting position 89 are the same as those of the first stable pole mounting position 88.

[0045] As shown in Figure 5 , the third stable pole mounting position 90 is provided on the first middle section 26, the third stable pole mounting position 90 is provided at the top of the first middle section 26, the number and geometric parameter characteristics of the third stable pole mounting position 90 are the same as those of the first stable pole mounting position 88.

[0046] As shown in Figure 6As shown, the second middle section 30 is provided with the first guide vane 170, the first spring mounting position 95, the first positive guide vane 153, the fourth stabilizer mounting position 92, the first water pressure flow channel 177, the first reverse guide vane 93, the first flow channel arc surface 94, the first flow channel arc surface 96, and the first suction flow channel 171. The fourth stabilizer mounting position 92 is arranged at the top of the second middle section 30. The number and geometric parameter characteristics of the fourth stabilizer mounting position 92 are the same as those of the first stabilizer mounting position 88. The first spring mounting position 95 is arranged on the first guide vane 170. The number of the first spring mounting position 95 is ≥3. The first positive guide vane 153 is arranged on the first guide vane 170. The first reverse guide vane 93 is arranged on the first guide vane 170. The first positive guide vane 153 is connected with the second middle section 30. The first reverse guide vane 93 is connected with the second middle section 30. The first positive guide vane 153, the first guide vane 170, and the second middle section 30 form the first water pressure flow channel 177. The first reverse guide vane 93, the first guide vane 170, and the second middle section 30 form the first suction flow channel 171. The first water pressure flow channel 177 and the first suction flow channel 171 are communicated to form an overall structure.

[0047] As shown, Figure 7 The third middle section 40 is provided with the second guide vane 172, the second spring mounting position 100, the second positive guide vane 154, the fifth stabilizer mounting position 97, the second water pressure flow channel 178, the second reverse guide vane 98, the third positive guide vane 155, the second flow channel arc surface 99, the second flow channel arc surface 101, the reverse guide vane 173, the second suction flow channel 174, and the third water pressure flow channel 179. The fifth stabilizer mounting position 97 is arranged at the top of the third middle section 40. The number and geometric parameter characteristics of the fifth stabilizer mounting position 97 are the same as those of the first stabilizer mounting position 88. The second spring mounting position 100 is arranged on the second guide vane 172. The number of the second spring mounting position 100 is ≥3 and equal to that of the first spring mounting position 95 arranged on the second middle section 30. The second positive guide vane 154 is arranged on the second guide vane 172. The second reverse guide vane 98 is arranged on the second guide vane 172. The third positive guide vane 155 is arranged on the reverse guide vane 173. The second positive guide vane 154 is connected with the third middle section 40. The second reverse guide vane 98 is connected with the third middle section 40. The third positive guide vane 155 is connected with the third middle section 40. The second positive guide vane 154, the second guide vane 172, and the third middle section 40 form the second water pressure flow channel 178. The second reverse guide vane 98, the second guide vane 172, and the third middle section 40 form the second suction flow channel 174. The third positive guide vane 155, the reverse guide vane 173, and the third middle section 40 form the third water pressure flow channel 179. The second water pressure flow channel 178 and the second suction flow channel 174 are communicated. The second suction flow channel 174 and the third water pressure flow channel 179 are communicated to form an overall structure.

[0048] As shown in Figure 1 and Figure 16 , the second flow channel bevel 103 and the third flow channel arc surface 102 are arranged on the induction wheel chamber 24, and the second flow channel bevel 103 and the third flow channel arc surface 102 are smoothly transitioned, so that the fluid flow is smooth.

[0049] As shown in Figure 1 and Figure 9 , the first positioning counterbore 104 and the first positioning groove 105 are arranged on the second heat exchange seat 9, and the first positioning counterbore 104 is arranged at the bottom of the first positioning groove 105.

[0050] As shown in Figure 1 and Figure 10 , the second positioning groove 106 and the second positioning counterbore 107 are arranged on the third heat exchange seat 66, and the second positioning groove 106 is arranged at the bottom of the second positioning counterbore 107.

[0051] As shown in Figure 1 and Figure 11 , the first stop groove 114, the first stop thread 113, the first mounting counterbore 112, the first boss 111 and the first mounting thread 110 are arranged on the second bearing box 12, the first stop groove 114, the first stop thread 113, the first mounting counterbore 112 and the first mounting thread 110 are arranged on the first boss 111, and the first stop thread 113, the first mounting counterbore 112 and the first mounting thread 110 are communicated.

[0052] As shown in Figure 1 and Figure 12 , the second mounting thread 115, the second mounting counterbore 116, the second stop groove 117, the second stop thread 118 and the second boss 119 are arranged on the first bearing box 53, the second mounting thread 115, the second mounting counterbore 116, the second stop groove 117 and the second stop thread 118 are arranged on the second boss 119, and the second mounting thread 115, the second mounting counterbore 116 and the second stop thread 118 are communicated.

[0053] As shown in Figure 1 and Figure 13 , the mouth ring groove 120 and the mouth ring friction surface 162 are arranged on the balance ring 43, and the mouth ring friction surface 162 is arranged in the mouth ring groove 120.

[0054] As shown in Figure 1 and Figure 14As shown, the stabilizer 32 is a rhombus structure, and two second upper arc surfaces 121 and two second lower arc surfaces 122 are arranged on the stabilizer 32. The second included angle of the two second upper arc surfaces 121 is b, and the angle value of b is 30°-60°. The fourth included angle of the two second lower arc surfaces 122 is d, and the angle value of d is 30°-60°. The angle value of b is equal to the angle value of d. The included angle between the second upper arc surface 121 and the second lower arc surface 122 is the first included angle a and the third included angle c, respectively. The angle value of a is 120°-150°, and the angle value of c is 120°-150°. The angle value of a is equal to the angle value of c. The geometric parameter characteristics of the rhombus of the stabilizer 32 are adapted to the geometric parameter characteristics of the first stabilizer mounting position 88 arranged on the water inlet section 1.

[0055] As shown in Figure 17 and Figure 18 As shown, the flow resistance ring 134 is provided with a third flow channel arc surface 146, and the radius size of the third flow channel arc surface 146 is equal to the radius size of the first flow channel arc surface 96 arranged on the second middle section 30 and the second flow channel arc surface 101 arranged on the third middle section 40.

[0056] As shown in Figure 1 As shown, the pump shaft 11 is provided with a cooling hole 10. The left heat exchanger 23 is provided with a first liquid inlet 165 and a first liquid outlet 166. The right heat exchanger 46 is provided with a second liquid outlet 167 and a second liquid inlet 168. A blocking plate 169 is arranged in the cylinder 31, and the blocking plate 169 is arranged between the cylinder 31 and the pump body, As shown in Figure 16 As shown, the first impeller 25 is provided with a first flow hole 136 and a first friction surface 131.

[0057] As shown in Figures 16-18 As shown, the second impeller 36 is provided with a second flow hole 145 and a second friction surface 138. The first port ring 127 is installed in the inducer chamber 24, and the inducer chamber 24 is installed in the first middle section 26. The second flow channel inclined surface 103 and the third flow channel circular arc surface 102 arranged on the inducer chamber 24 are matched with the first flow channel inclined surface 91 arranged on the first middle section 26 to form a flow channel surface 128. The second port ring 144 is installed on the second middle section 30 and the third middle section 40, respectively. The balance ring 43 is installed on the water outlet section 45. The first corrugated spring 133 is installed in the first spring mounting position 95. The first friction ring 132 is installed on the first corrugated spring 133. The second corrugated spring 140 is installed in the second spring mounting position 100. The second friction ring 139 is installed on the second corrugated spring 140. The outer friction ring 149 and the inner friction ring 151 are installed on the third impeller 41.

[0058] As shown in Figure 1 , Figures 16-19As shown, the inlet section 1, the outlet section 45, the first middle section 26, the second middle section 30, and the third middle section 40 are assembled together in series through the stabilizing lever 32. The cylinder 31 is matched with the inlet section 1 and the outlet section 45. The first baffle 29, the second baffle 34, and the third baffle 38 are respectively matched with the blocking plate 169, the cylinder 31, the first middle section 26, the second middle section 30, and the last middle section after being placed into the cylinder 31. The inducer 180, the first impeller 25, the second impeller 36, the third impeller 41, and the balance drum 44 are respectively installed on the pump shaft 11 and matched with the first middle section 26, the second middle section 30, and the third middle section 40. The outer friction ring 149 and the inner friction ring 151 provided on the third impeller 41 are matched with the port ring groove 120 and the port ring friction surface 162 on the balance ring 43. The first friction surface 131 provided on the first impeller 25 is matched with the first friction ring 132. The second friction surface 138 provided on the second impeller 36 is matched with the second friction ring 139. The second heat exchange seat 9 is installed on the outlet section 45. The pressure relief seat 108 is installed on one end of the outlet section 45. The third heat exchange seat 66 is installed on one end of the pressure relief seat 108. The left mechanical seal 18 is installed on the pump shaft 11 and matched with the second heat exchange seat 9. The right mechanical seal 52 is installed on the pump shaft 11 and matched with the third heat exchange seat 66.

[0059] As shown, Figure 1 the first sliding bearing 196 is installed in the second bearing box 12. The second bearing box 12 is provided with the second bearing box heat exchange cavity 17. The third corrugated spring 54, the angular contact ball bearing 71, and the second sliding bearing 197 are installed in the first bearing box 53. The first bearing box 53 is provided with the first bearing box heat exchange cavity 59. The second bearing box 12 is matched with the pump shaft 11 and then installed on the second heat exchange seat 9. The first boss 111 provided on the second bearing box 12 is matched with the first positioning groove 105 provided on the second heat exchange seat 9. The first bearing box 53 is matched with the pump shaft 11 and then installed on the third heat exchange seat 66. The second boss 119 provided on the first bearing box 53 is matched with the second positioning groove 106 provided on the third heat exchange seat 66. The first heat exchange seat 163 is installed on the first bearing box 53 to form a multistage pump. The pump shaft 11, the inducer 180, the first impeller 25, the second impeller 36, the third impeller 41, the balance drum 44, the left mechanical seal 18, the right mechanical seal 52, the first sliding bearing 196, the angular contact ball bearing 71, and the second sliding bearing 197 constitute the rotor component of the multistage pump.

[0060] As shown, Figure 1 and Figure 15As shown, the multi-stage pump is installed on the base 198, the first lifting bolt 123 is installed in the first installation threaded teeth 110 through the first stop threaded teeth 113 and the first installation counterbore 112, cooperates with the first positioning counterbore 104, the first locking nut 124 is installed in the first stop threaded teeth 113 to compress the first lifting bolt 123, the first stop washer 125 cooperates with the first locking nut 124 through the first positioning slot 105, the first stop nut 126 is installed in the first stop threaded teeth 113 to compress the first stop washer 125, the first stop washer 125 is folded back through the first stop slot 114 and cooperates with the second bearing box 12, and the first stop washer 125 is fixed after being folded back and cooperating with the inside of the first stop nut 126 to stop the first lifting bolt 123.

[0061] As shown, Figure 19 the second lifting bolt 156 is installed in the second installation threaded teeth 115 through the second stop threaded teeth 118 and the second installation counterbore 116, cooperates with the second positioning counterbore 107, the second locking nut 157 is installed in the second stop threaded teeth 118 to compress the second lifting bolt 156, the second stop washer 158 cooperates with the second locking nut 157 through the second positioning slot 106, the second stop nut 159 is installed in the second stop threaded teeth 118 to compress the second stop washer 158, the second stop washer 158 is folded back through the second stop slot 117 and cooperates with the first bearing box 53, and the second stop washer 158 is fixed after being folded back and cooperating with the inside of the second stop nut 159 to stop the second lifting bolt 156.

[0062] As shown, Figure 1 the balance pipe 37 is installed on the water inlet section 1 and the water outlet section 45, the left heat exchanger 23 and the right heat exchanger 46 are respectively installed on the base 198, the liquid inlet main pipe 58 and the liquid outlet main pipe 57 are respectively installed on the base 198, the exhaust pipe 199 is installed on the first heat exchange seat 163, and the degassing pipe 181 is installed on the water inlet section 1; the first liquid inlet pipe 55 is simultaneously installed on the first heat exchange seat 163 and the liquid inlet main pipe 58, the second liquid inlet pipe 62 is simultaneously installed on the first bearing box heat exchange cavity 59 and the liquid inlet main pipe 58, the third liquid inlet pipe 70 is simultaneously installed on the pressure relief seat 108 and the liquid inlet main pipe 58, the fourth liquid inlet pipe 74 is simultaneously installed on the cylinder body 31 and the liquid inlet main pipe 58, the fifth liquid inlet pipe 78 is simultaneously installed on the cylinder body 31 and the liquid inlet main pipe 58, the sixth liquid inlet pipe 82 is simultaneously installed on the cylinder body 31 and the liquid inlet main pipe 58, the seventh liquid inlet pipe 86 is simultaneously installed on the cylinder body 31 and the liquid inlet main pipe 58, the eighth liquid inlet pipe 4 is simultaneously installed on the water inlet section 1 and the liquid inlet main pipe 58, the ninth liquid inlet pipe 14 is simultaneously installed on the second bearing box heat exchange cavity 17 and the liquid inlet main pipe 58, the tenth liquid inlet pipe 20 is simultaneously installed on the left heat exchanger 23 and the left mechanical seal 18, and the eleventh liquid inlet pipe 49 is simultaneously installed on the right heat exchanger 46 and the right mechanical seal 52.

[0063] AsFigure 1 As shown, the first liquid outlet pipe 61 is installed on the first bearing box heat exchange chamber 59 and the liquid outlet main pipe 57 at the same time, the second liquid outlet pipe 65 is installed on the right mechanical seal 52 and the liquid outlet main pipe 57 at the same time, the third liquid outlet pipe 69 is installed on the pressure relief seat 108 and the liquid outlet main pipe 57 at the same time, the fourth liquid outlet pipe 73 is installed on the cylinder 31 and the liquid outlet main pipe 57 at the same time, the fifth liquid outlet pipe 77 is installed on the cylinder 31 and the liquid outlet main pipe 57 at the same time, and the sixth liquid outlet pipe 81 is installed on the cylinder 31 and the liquid outlet main pipe 57 at the same time. The seventh liquid outlet pipe 85 is installed on the cylinder 31 and the liquid outlet main pipe 57 at the same time, the eighth liquid outlet pipe 3 is installed on the water inlet section 1 and the liquid outlet main pipe 57 at the same time, the ninth liquid outlet pipe 8 is installed on the left mechanical seal 18 and the liquid outlet main pipe 57 at the same time, the tenth liquid outlet pipe 13 is installed on the second bearing box heat exchange chamber 17 and the liquid outlet main pipe 57 at the same time, the eleventh liquid outlet pipe 21 is installed on the left heat exchanger 23 and the left mechanical seal 18 at the same time, and the twelfth liquid outlet pipe 48 is installed on the right heat exchanger 46 and the right mechanical seal 52 at the same time.

[0064] like Figure 1 As shown, the first temperature sensor 60 is installed on the first liquid outlet pipe 61, the second temperature sensor 194 is installed on the first bearing box 53, the third temperature sensor 64 is installed on the second liquid outlet pipe 65, the fourth temperature sensor 68 is installed on the third liquid outlet pipe 69, the fifth temperature sensor 72 is installed on the fourth liquid outlet pipe 73, the sixth temperature sensor 76 is installed on the fifth liquid outlet pipe 77, the seventh temperature sensor 80 is installed on the sixth liquid outlet pipe 81, the eighth temperature sensor 84 is installed on the seventh liquid outlet pipe 85, the ninth temperature sensor 2 is installed on the eighth liquid outlet pipe 3, the tenth temperature sensor 7 is installed on the liquid outlet pipe 8, the eleventh temperature sensor 15 is installed on the tenth liquid outlet pipe 13, and the twelfth temperature sensor 16 is installed on the tenth liquid outlet pipe 14. Sensor 193 is installed on the second bearing box 12, the thirteenth temperature sensor 184 is installed on the second bearing box 12 and cooperates with the sliding bearing 196, the fourteenth temperature sensor 19 is installed on the eleventh liquid outlet pipe 21, the fifteenth temperature sensor 51 is installed on the twelfth liquid outlet pipe 48, the sixteenth temperature sensor 188 is installed on the first bearing box 53 and cooperates with the second sliding bearing 197, the seventeenth temperature sensor 189 is installed on the first bearing box 53 and cooperates with the angular contact ball bearing 71, the eighteenth temperature sensor 200 is installed in the first probe installation position 202 set in the water inlet section 1, and the nineteenth temperature sensor 201 is installed in the second probe installation position 203 set in the water outlet section 45.

[0065] like Figure 1As shown, the first pressure sensor 186 is installed on the degassing pipe 181, the second pressure sensor 42 is installed on the balancing pipe 37, and the third pressure sensor 190 is installed on the exhaust pipe 199. The first regulating valve 56 is installed on the first liquid inlet pipe 55, the second regulating valve 63 is installed on the second liquid inlet pipe 62, the third regulating valve 50 is installed on the third liquid inlet pipe 70, the fourth regulating valve 75 is installed on the fourth liquid inlet pipe 74, the fifth regulating valve 79 is installed on the fifth liquid inlet pipe 78, the sixth regulating valve 83 is installed on the sixth liquid inlet pipe 82, the seventh regulating valve 87 is installed on the seventh liquid inlet pipe 86, the eighth regulating valve 5 is installed on the eighth liquid inlet pipe 4, the ninth regulating valve 16 is installed on the ninth liquid inlet pipe 14, the tenth regulating valve 22 is installed on the first liquid inlet port 165, the eleventh regulating valve 28 is installed on the balancing pipe 37, the twelfth regulating valve 47 is installed on the second liquid inlet port 168, and the thirteenth regulating valve 195 is installed on the exhaust pipe 199.

[0066] like Figure 1 As shown, the first vibration sensor 182 is installed on the second bearing box 12, the second vibration sensor 183 is installed on the second bearing box 12, and the third vibration sensor 185 is installed on the second bearing box 12 to form vibration detection of the second bearing box 12 at the left end of the multi-stage pump in the X, Y, and Z directions. The fourth vibration sensor 187 is installed on the first bearing box 53, the fifth vibration sensor 191 is installed on the first bearing box 53, and the sixth vibration sensor 192 is installed on the first bearing box 53 to form vibration detection of the first bearing box 53 at the right end of the multi-stage pump in the X, Y, and Z directions.

[0067] like Figure 1 、 Figures 3-7 、 Figure 14 and Figure 20As shown, the stabilizing bars 32 are respectively matched with the first stabilizing bar installation position 88 provided on the water inlet section 1, the third stabilizing bar installation position 90 provided on the first middle section 26, the fourth stabilizing bar installation position 92 provided on the second middle section 30, the fifth stabilizing bar installation position 97 provided on the third middle section 40 and the second stabilizing bar installation position 89 provided on the water outlet section 45, the two second upper arc surfaces 121 of the stabilizing bars 32 are respectively matched with the two first upper arc surfaces 160 of the first stabilizing bar installation position 88, the third stabilizing bar installation position 90, the fourth stabilizing bar installation position 92, the fifth stabilizing bar installation position 97 and the second stabilizing bar installation position 89, the two second lower arc surfaces 122 of the stabilizing bars 32 are respectively matched with the two first lower arc surfaces 161 of the first stabilizing bar installation position 88, the third stabilizing bar installation position 90, the fourth stabilizing bar installation position 92, the fifth stabilizing bar installation position 97 and the second stabilizing bar installation position 89, the stabilizing bars 32 are respectively matched with the first stabilizing bar installation position 88 provided on the water inlet section 1, the third stabilizing bar installation position 90 provided on the first middle section 26, the fourth stabilizing bar installation position 92 provided on the second middle section 30, the fifth stabilizing bar installation position 97 provided on the third middle section 40 and the second stabilizing bar installation position 89 provided on the water outlet section 45 to form a pump cavity stabilizing system of the multi-stage pump, effectively preventing the radial rotation of the first middle section 26, the second middle section 30 and the third middle section 40, and ensuring the safe and reliable operation of the multi-stage pump.

[0068] The first lifting bolt 123, the first stop thread 113, the first installation counter bore 112, the first installation thread 110, the first positioning counter bore 104, the first locking nut 124, the first stop washer 125, the first positioning groove 105, the first stop nut 126, the first stop groove 114, the second bearing box 12, the second heat exchange seat 9 and the second lifting bolt 156, the second stop thread 118, the second installation counter bore 116, the second installation thread 115, the second positioning counter bore 107, the second locking nut 157, the second stop washer 158, the second positioning groove 106, the second stop nut 159, the second stop groove 117, the first bearing box 53, the third heat exchange seat 66 and the rotor component combination form a lifting system of the rotor component of the multi-stage pump, when the rotor component is lowered due to the assembly precision of each component or the corrosion of the assembly stop of the bearing box after long time use, affecting the concentricity of the rotor component and the components, the lifting bolt of the lifting system of the rotor component is adjusted to lift the rotor component as a whole to ensure the concentricity and ensure the safe and reliable operation of the multi-stage pump.

[0069] The first inlet section 1, the first middle section 26, the cylinder 31, the first partition 29 and the blocking plate 169 combine to form a first-stage middle section heat exchange cavity 27, the first middle section 26, the second middle section 30, the cylinder 31, the second partition 34, the first partition 29 and the blocking plate 169 combine to form a middle section first heat exchange cavity 33, the second middle section 30, the cylinder 31, the second partition 34, the third middle section 40, the third partition 38 and the blocking plate 169 combine to form a middle section second heat exchange cavity 35, the second middle section 30, the cylinder 31, the third middle section 40, the partition 38 and the blocking plate 169 combine to form a last-stage middle section heat exchange cavity 39, the fourth liquid outlet pipe 73 and the fourth liquid inlet pipe 74 communicate with the last-stage middle section heat exchange cavity 39, the fifth liquid outlet pipe 77 and the fifth liquid inlet pipe 78 communicate with the middle section second heat exchange cavity 35, the sixth liquid outlet pipe 81 and the sixth liquid inlet pipe 82 communicate with the middle section first heat exchange cavity 33, and the seventh liquid outlet pipe 85 and the seventh liquid inlet pipe 86 communicate with the first-stage middle section heat exchange cavity 27; the first-stage middle section heat exchange cavity 27, the middle section first heat exchange cavity 33, the middle section second heat exchange cavity 35, the last-stage middle section heat exchange cavity 39, the liquid inlet main pipe 58, the liquid outlet main pipe 57, the fourth liquid inlet pipe 74, the fourth liquid outlet pipe 73, the fifth temperature sensor 72, the fifth liquid inlet pipe 78, the sixth temperature sensor 76, the fifth liquid outlet pipe 77, the fifth regulating valve 79, the sixth liquid inlet pipe 82, the seventh temperature sensor 80, the sixth liquid outlet pipe 81, the sixth regulating valve 83, the seventh liquid inlet pipe 86, the eighth temperature sensor 84, the seventh liquid outlet pipe 85, the seventh regulating valve 87, the eighteenth temperature sensor 200 and the nineteenth temperature sensor 201 combine to form a multi-stage pump cavity body staged cooling and heating system, and the system is connected with the field network control cabinet and the central control room computer or the APP of the mobile phone and the tablet computer to sequentially perform the cooling, heating and temperature maintaining operations on the pump cavity, completely solves the influence of temperature change on the cavity components, and ensures the safe and reliable operation of the multi-stage pump.

[0070] As Figure 16As shown, the flow channel surface 128 and the first impeller 25 form a primary resistance flow cavity 129, the first impeller 25 and the second middle section 30, the first friction surface 131, the first friction ring 132 and the first corrugated spring 133 form a second impeller cover plate cavity 175. When the rotor components are in operation, the medium delivered by the first impeller 25 will flow from high pressure to low pressure, and the primary medium resistance flow 130 will be generated under the guidance of the flow channel surface 128. The high pressure of the primary medium resistance flow 130 will act on the first impeller 25, so that the pressure of the primary resistance flow cavity 129 and the second impeller cover plate cavity 175 is balanced, and thus the axial force generated by the first impeller 25 is eliminated. The first impeller 25, the second middle section 30, the first friction surface 131, the first friction ring 132, the first corrugated spring 133 and the resistance flow ring 134 form a first leakage flow cavity 135. The first leakage flow cavity 135 is communicated with the suction inlet of the first impeller 25 through the first leakage flow hole 136. When the first friction surface 131 or the first friction ring 132 is damaged due to long-time operation of the multi-stage pump, the high-pressure medium in the second impeller cover plate cavity 175 will leak. The leaked medium will flow into the first leakage flow cavity 135 and then enter the suction inlet of the first impeller 25 through the first leakage flow hole 136, so that the axial force generated by the medium in the first leakage flow cavity 135 on the first impeller 25 is eliminated.

[0071] As shown in the drawings, Figure 17 The first flow channel arc surface 94 provided on the second middle section 30 and the second impeller 36 form a secondary resistance flow cavity 142, and the second impeller 36 and the second middle section 30, the second friction surface 138, the second friction ring 139 and the second corrugated spring 140 form a second impeller cover plate cavity 175. When the rotor components are in operation, the medium delivered by the second impeller 36 will flow from high pressure to low pressure, and the secondary medium resistance flow 143 will be generated under the guidance of the first flow channel arc surface 94. The high pressure of the secondary medium resistance flow 143 will act on the second impeller 36, so that the pressure of the secondary resistance flow cavity 142 and the second impeller cover plate cavity 175 is balanced, and thus the axial force generated by the second impeller 36 is eliminated. The second impeller 36, the second middle section 30, the second friction surface 138, the second friction ring 139, the second corrugated spring 140 and the resistance flow ring 134 form a second leakage flow cavity 137. The second leakage flow cavity 137 is communicated with the suction inlet of the second impeller 36 through the second leakage flow hole 145. When the second friction surface 138 or the second friction ring 139 is damaged due to long-time operation of the multi-stage pump, the high-pressure medium in the second impeller cover plate cavity 175 will leak. The leaked medium will flow into the second leakage flow cavity 137 and then enter the suction inlet of the second impeller 36 through the second leakage flow hole 145, so that the axial force generated by the medium in the second leakage flow cavity 137 on the second impeller 36 is eliminated. As shown in the drawings, Figure 18As shown, the second flow channel arc surface 99 of the third middle section 40 is arranged to form a final stage resistance flow cavity 148 with the third impeller, and the third impeller 41 is arranged to form a third impeller cover cavity 176 with the third middle section 40, the water outlet section 45, the balance ring 43, the outer friction ring 149 and the inner friction ring 151. When the rotor part is in operation, the medium delivered by the third impeller 41 flows from high pressure to low pressure, and the medium is guided by the second flow channel arc surface 99 to generate a final stage medium resistance flow 147, and the high pressure of the final stage medium resistance flow 147 acts on the third impeller 41, so that the pressure of the final stage resistance flow cavity 148 and the third impeller cover cavity 176 is balanced, thereby eliminating the axial force generated by the third impeller 41. The third impeller 41 is arranged to form a balance cavity 150 with the balance ring 43, the outer friction ring 149, the inner friction ring 151, the balance drum 44 and the pump shaft 11. The high pressure medium in the third impeller cover cavity 176 flows into the balance cavity 150 through the balance ring 43, the outer friction ring 149 and the inner friction ring 151, and the pressure of the medium in the balance cavity 150 acts on the balance drum 44 and then flows out between the balance drum 44 and the balance ring 43, thereby eliminating the axial force generated by the medium in the balance cavity 150 on the third impeller 41.

[0072] In this way, the first stage resistance flow cavity 129, the second impeller cover cavity 175, the first discharge flow cavity 135, the secondary resistance flow cavity 142, the second discharge flow cavity 137, the final stage resistance flow cavity 148 and the balance cavity 150 combine to form an impeller axial force balance system of the multi-stage pump, which eliminates the large axial force generated by each impeller and ensures safe and reliable operation of the multi-stage pump.

[0073] As shown in the figure, Figure 1 The water outlet section 45 is arranged to form a pressure relief cavity 109 with the balance ring 43, the balance drum 44, the pressure relief seat 108 and the third heat exchange seat 66. The pressure relief cavity 109 is communicated with the water inlet section 1 through the balance pipe 37. The pressure of the medium in the balance cavity 150 acts on the balance drum 44 and then flows between the balance drum 44 and the balance ring 43 into the pressure relief cavity 109, and then flows into the water inlet section 1 through the balance pipe 37 and enters the inducer 180 again, and continuously circulates to balance the small axial force.

[0074] The balance ring 43, the balance drum 44, the balance cavity 150, the pressure relief cavity 109, the balance pipe 37, the water inlet section 1, the eleventh adjusting valve 28 and the second pressure sensor 42 combine to form a pump axial force balance system of the multi-stage pump, which ensures safe and reliable operation of the multi-stage pump.

[0075] The cooling hole 10 arranged on the pump shaft 11 forms a rotor heat exchange cavity 164 with the left mechanical seal 18, the right mechanical seal 52, the exhaust pipe 199 and the first heat exchange seat 163. The first liquid inlet pipe 55 communicates with the liquid inlet main pipe 58 and the rotor heat exchange cavity 164. The exhaust pipe 199 communicates with the rotor heat exchange cavity 164. The exhaust pipe 199 communicates with the atmosphere or a special steam collecting device. The second liquid outlet pipe 65 communicates with the liquid outlet main pipe 57 and the rotor heat exchange cavity 164. The liquid outlet pipe 8 communicates with the liquid outlet main pipe 57 and the rotor heat exchange cavity 164. The rotor heat exchange cavity 164, the first liquid inlet pipe 55, the liquid inlet main pipe 58, the exhaust pipe 199, the second liquid outlet pipe 65, the liquid outlet main pipe 57, the ninth liquid outlet pipe 8, the first regulating valve 56, the third temperature sensor 64, the tenth temperature sensor 7, the third pressure sensor 190 and the thirteenth regulating valve 195 form a rotor component cooling, heat preservation and heating system of the multi-stage pump in combination, and can continuously and effectively control the temperature change of the pump rotor component in the starting and running process, and ensure the safe and reliable operation of the multi-stage pump.

[0076] As Figure 16 and Figure 17As shown, after the flow blocking ring 134 is installed behind the second middle section 30 and the third middle section 40, the third flow channel arc surface 146 provided on the flow blocking ring 134 corresponds to the first flow channel arc surface 96 provided on the second middle section 30 and the second flow channel arc surface 101 provided on the third middle section 40, respectively, to form a smooth and smooth flow channel, so that the medium in the first suction flow channel 171 provided on the second middle section 30 forms a smooth medium flow state 141, which smoothly flows into the suction inlet of the second impeller 36, prevents the flowing pressure medium from directly contacting the pump shaft 11, eliminates the radial force of the pressure medium on the pump shaft 11 to cause multiple bending and alternating deformation of the rotor component, and the medium in the second suction flow channel 174 provided on the third middle section 40 forms a smooth medium flow state 141, which smoothly flows into the suction inlet of the third impeller 41, prevents the flowing pressure medium from directly contacting the pump shaft 11, eliminates the radial force of the pressure medium on the pump shaft 11 to cause bending deformation of the rotor component; when the working flow of the pump is less than or greater than the design rated flow due to some reasons (change of system working pressure of pipe network, change of required flow at the end of device system, change of power grid system frequency, change of pump inlet pipeline system device head, stall or overspeed of pump driving machine system, etc.), the sharp contradiction between the working flow of the pump and the design rated flow will cause a simple pressure fluctuation directly acting on the impeller, thereby changing the balanced axial force, which will cause a larger axial fluctuation of the pump rotor component. Axial fluctuation directly acts on the mechanical seal and bearing of the pump, thereby shortening the service life of the pump. The first wave spring 133 installed on the second middle section 30 and the second wave spring 140 installed on the third middle section 40 and the third wave spring 54 installed on the first bearing box 53 can completely eliminate the axial fluctuation of the pump rotor component caused by the axial fluctuation of the pump rotor component.

[0077] The flow blocking ring 134, the second middle section 30, the third middle section 40, the first wave spring 133, the second wave spring 140 and the third wave spring 54 and the second middle section 30, the third middle section 40 and the first bearing box 53 form a rotor impeller inter-stage buffer system of the multi-stage pump, which eliminates the axial fluctuation of the pump rotor component and ensures the safe and reliable operation of the multi-stage pump.

[0078] The multi-stage pump is a high-lift pump that uses multiple impellers in series to stack the lift of each impeller. The conveying medium is continuously sucked into the inlet section 1 of the pump, and then flows into the inducer 180, the first impeller 25, the first pressure water flow channel 177 and the first suction flow channel 171 provided on the first middle section 30, the second impeller 36, the second pressure water flow channel 178 and the second suction flow channel 174 provided on the second middle section 40, the third impeller 41, and the third pressure water flow channel 179 provided on the third middle section 40, and then flows out through the outlet section 45. Therefore, the inlet section 1 of the pump bears low pressure of the medium, i.e. the left end side of the multi-stage pump, and the outlet section 45 bears high pressure of the medium, i.e. the right end side of the multi-stage pump. Therefore, the left mechanical seal 18 and the left heat exchanger 23 bear low pressure, and the right mechanical seal 52 and the right heat exchanger 46 bear high pressure. That is, the mechanical seals and heat exchangers at the left and right ends are selected separately, which can effectively save production cost and effectively control operation reliability.

[0079] The inlet section 1 and the second heat exchange seat 9 form a left heat exchange cavity 6. The eighth liquid inlet pipe 4 is in communication with the liquid inlet main pipe 58 and the left heat exchange cavity 6. The eighth liquid outlet pipe 3 is in communication with the liquid outlet main pipe 57 and the left heat exchange cavity 6. The left heat exchange cavity 6, the eighth liquid inlet pipe 4, the liquid inlet main pipe 58, the eighth liquid outlet pipe 3, the liquid outlet main pipe 57, the ninth temperature sensor 2, the eighth adjusting valve 5, the tenth liquid inlet pipe 20, the eleventh liquid outlet pipe 21, the left heat exchanger 23, the tenth adjusting valve 22, and the fourteenth temperature sensor 19 form a low-pressure mechanical seal cooling, heat preservation and heating system of the multi-stage pump, and are connected with the field network control cabinet and the central control room computer or the APP of the mobile phone and tablet computer, to ensure the safe and reliable operation of the left mechanical seal 18.

[0080] The pressure relief seat 108 and the third heat exchange seat 66 form a right heat exchange cavity 67. The third liquid inlet pipe 70 is in communication with the liquid inlet main pipe 58 and the right heat exchange cavity 67. The third liquid outlet pipe 69 is in communication with the liquid outlet main pipe 57 and the right heat exchange cavity 67. The right heat exchange cavity 67, the third liquid inlet pipe 70, the liquid inlet main pipe 58, the third liquid outlet pipe 69, the liquid outlet main pipe 57, the fourth temperature sensor 68, the third adjusting valve 50, the eleventh liquid inlet pipe 49, the twelfth liquid outlet pipe 48, the right heat exchanger 46, the twelfth adjusting valve 47, and the fifteenth temperature sensor 51 form a high-pressure mechanical seal cooling, heat preservation and heating system of the multi-stage pump, and are connected with the field network control cabinet and the central control room computer or the APP of the mobile phone and tablet computer, to ensure the safe and reliable operation of the right mechanical seal 52.

[0081] The ninth liquid inlet pipe 14 is in communication with the liquid inlet main pipe 58 and the second bearing box heat exchange cavity 17, the tenth liquid outlet pipe 13 is in communication with the liquid outlet main pipe 57 and the second bearing box heat exchange cavity 17, the second liquid inlet pipe 62 is in communication with the liquid inlet main pipe 58 and the first bearing box heat exchange cavity 59, the first liquid outlet pipe 61 is in communication with the liquid outlet main pipe 57 and the first bearing box heat exchange cavity 59, the ninth liquid inlet pipe 14, the liquid inlet main pipe 58, the second bearing box heat exchange cavity 17, the tenth liquid outlet pipe 13, the liquid outlet main pipe 57, the second liquid inlet pipe 62, the first bearing box heat exchange cavity 59, the first liquid outlet pipe 61, the eleventh temperature sensor 15, the ninth regulating valve 16, the first temperature sensor 60 and the second regulating valve 63 form a bearing box cooling and heating system of the multi-stage pump, and are connected with the field network control cabinet and the central control room computer or the APP of the mobile phone and the tablet computer, to ensure the safe and reliable operation of the bearing of the multi-stage pump.

[0082] The angular contact ball bearing 71, the first corrugated spring 133, the second corrugated spring 140 and the third corrugated spring 54 form a rotor component residual axial force buffering system of the multi-stage pump in combination with the first bearing box 53, the corrugated spring bears the instantaneous change of the axial movement of the rotor component, the angular contact ball bearing 71 bears the small axial force after the balance of the movement, to ensure the safe and reliable operation of the multi-stage pump.

[0083] The degassing pipe 181 is installed on the water inlet section 1, the first pressure sensor 186 is installed on the degassing pipe 181, the degassing pipe 181 is in communication with the suction inlet of the inducer 180 and the first impeller 25 respectively through the water inlet section 1, the first middle section 26 and the inducer chamber 24, the degassing pipe 181 is connected with an external degassing device, the degassing pipe 181, the water inlet section 1, the first pressure sensor 186, the first middle section 26, the inducer chamber 24 and the external degassing device form a water inlet degassing and anti-cavitation system of the multi-stage pump in combination, and are connected with the field network control cabinet and the central control room computer or the APP of the mobile phone and the tablet computer, to ensure the normal start and continuous operation of the degassing and anti-cavitation function of the multi-stage pump, and ensure the safe and reliable operation of the multi-stage pump.

[0084] The first vibration sensor 182, the second vibration sensor 183, and the third vibration sensor 185 are respectively installed on the second bearing box 12 and are in communication with the field network control cabinet or the central control room computer of the pump, the field network control cabinet and the central control room computer are in communication with the APP of the mobile phone or the tablet computer through a wireless network, forming vibration detection of the X, Y, and Z directions of the second bearing box 12 of the multistage pump, the fourth vibration sensor 187, the fifth vibration sensor 191, and the sixth vibration sensor 192 are respectively installed on the first bearing box 53 and are in communication with the field network control cabinet or the central control room computer of the pump behind the pump, the field network control cabinet and the central control room computer are in communication with the APP of the mobile phone or the tablet computer through a wireless network, forming vibration detection of the X, Y, and Z directions of the first bearing box 53 of the multistage pump; the first vibration sensor 182, the second vibration sensor 183, the third vibration sensor 185, the second bearing box 12, the fourth vibration sensor 187, the fifth vibration sensor 191, the sixth vibration sensor 192, the first bearing box 53, and the APP of the mobile phone and the tablet computer in combination with the field network control cabinet and the central control room computer form a bearing vibration and temperature measurement system of the multistage pump, forming real-time monitoring of the continuous operation of the pump, improving the operation stability, reliability, and safety of the pump.

[0085] Inlet section 1, outlet section 45, first middle section 26, second middle section 30, third middle section 40, balance drum 44 and balance ring 43, inducer 180, first impeller 25, second impeller 36, third impeller 41, second bearing housing 12, first bearing housing 53, inducer chamber 24, second heat exchange seat 9, third heat exchange seat 66, pressure relief seat 108, pump shaft 11, cylinder 31, first partition 29, second partition 34, third partition 38, blocking plate 169, left mechanical seal 18, right mechanical seal 52, left heat exchanger 23, right heat exchanger 46, stabilizing lever 32, first heat exchange seat 163, inlet liquid main pipe 58, outlet liquid main pipe 57, first inlet liquid pipe 55, second inlet liquid pipe 62, third inlet liquid pipe 70, fourth inlet liquid pipe 74, fifth inlet liquid pipe 78, sixth inlet liquid pipe 82, seventh inlet liquid pipe 86, eighth inlet liquid pipe 4, ninth inlet liquid pipe 14, tenth inlet liquid pipe 20, eleventh inlet liquid pipe 49, first outlet liquid pipe 61, second outlet liquid pipe 65, third outlet liquid pipe 69, fourth outlet liquid pipe 73, fifth outlet liquid pipe 77, sixth outlet liquid pipe 81, seventh outlet liquid pipe 85, eighth outlet liquid pipe 3, ninth outlet liquid pipe 8, tenth outlet liquid pipe 13, eleventh outlet liquid pipe 21, twelfth outlet liquid pipe 48, first temperature sensor 60, second temperature sensor 194, third temperature sensor 64, fourth temperature sensor 68, fifth temperature sensor 72, sixth temperature sensor 76, seventh temperature sensor 80, eighth temperature sensor 84, ninth temperature sensor 2, tenth temperature sensor 7, eleventh temperature sensor 15, twelfth temperature sensor 193, thirteenth temperature sensor 184, fourteenth temperature sensor 19, fifteenth temperature sensor 51, sixteenth temperature sensor 188, seventeenth temperature sensor 189, eighteenth temperature sensor 200, nineteenth temperature sensor 201, first pressure sensor 186, second pressure sensor 42, third pressure sensor 190, first regulating valve 56, second regulating valve 63, third regulating valve 50, fourth regulating valve 75, fifth regulating valve 79, sixth regulating valve 83, seventh regulating valve 87, eighth regulating valve 5, ninth regulating valve 16, tenth regulating valve 22, eleventh regulating valve 28, twelfth regulating valve 47, thirteenth regulating valve 195, angular contact ball bearing 71, left mechanical seal 18, right mechanical seal 52, first lifting bolt 123, second lifting bolt 156, first locking nut 124, second locking nut 157, first stop washer 125, second stop washer 158, first stop nut 126, second stop nut 159, balance pipe 37, first sliding bearing 196, second sliding bearing 197, first vibration sensor 182, second vibration sensor 183, third vibration sensor 185, fourth vibration sensor 187, fifth vibration sensor 191, sixth vibration sensor 192, base 198, first lip ring 127, first friction ring 132, second friction ring 139, first corrugated spring 133, second corrugated spring 140, third corrugated spring 54,The combination of the flow blocking ring 134, the second port ring 144, the outer friction ring 149, the inner friction ring 151, the degassing pipe 181 and the exhaust pipe 199 constitutes a pump cavity stabilizing system, a rotor component lifting system, a pump cavity staged temperature lowering and maintaining and raising system, an impeller axial force balancing system, a pump axial force balancing system, a rotor component temperature lowering and maintaining and raising system, a rotor impeller inter-stage buffering system, a low-pressure seal temperature lowering and maintaining and raising system, a high-pressure seal temperature lowering and maintaining and raising system, a bearing box temperature lowering and maintaining and raising system, a rotor component residual axial force buffering system, and a pump water diversion, degassing, cavitation resistance system and bearing vibration and temperature measurement system, which, in combination with a field network control cabinet and a central control room computer or a mobile phone and tablet computer APP, forms a higher stability and reliability multi-stage pump.

[0086] The higher stability and reliability multi-stage pump can install more impellers (up to 30 stages or more) in series, so that the flow rate of the pump reaches 6000 m 3 / h or more, the pump head reaches 4500 m or more, the pump speed reaches between 3000 r / min and 20000 r / min, and the pump matching power reaches 20000 Kw or more; and is provided with a pump cavity stabilizing system, a rotor component lifting system, a pump cavity staged temperature lowering and maintaining and raising system, an impeller axial force balancing system, a pump axial force balancing system, a rotor component temperature lowering and maintaining and raising system, a rotor impeller inter-stage buffering system, a low-pressure seal temperature lowering and maintaining and raising system, a high-pressure seal temperature lowering and maintaining and raising system, a bearing box temperature lowering and maintaining and raising system, a rotor component residual axial force buffering system, and a pump water diversion, degassing, cavitation resistance system and bearing vibration and temperature measurement system, which can completely solve the problems of pump starting difficulty, cavity component deformation, rotor component and cavity sagging, operation cavitation, rotor component movement, huge and unbalanced axial force, residual axial force and operation pipe network working condition pressure fluctuation axial force, inter-stage radial force generation, large operation vibration, large operation noise, leakage during transportation, high production manufacturing cost, long axial assembly size of the pump, weak overall rigidity and strength of the pump cavity and rotor component, brittle fracture and stress fracture of the part material caused by temperature, pump shaft alternating fatigue fracture and other complex technical defect problems, ensures safer, more reliable and stable operation of the multi-stage pump, improves the service life of the pump, reduces the production, operation, maintenance and repair costs of the pump, improves the production and use life cycle of the pump, enables the multi-stage pump to be applied to more kinds of complex and variable fields and working conditions, and generates more economic value and social benefits.

[0087] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and replacements without departing from the technical principles of the present application, and these improvements and replacements should also be considered within the protection scope of the present application.

Claims

1. A multi-stage pump with higher stability and reliability, characterized by, The pump comprises: a pump body; a pump shaft arranged in the pump body; an impeller assembly mounted on the pump shaft and located between the pump body and the pump shaft; a first bearing box mounted on one end of the pump body, one end of the pump shaft extending out of the pump body and connected to a bearing in the first bearing box; a lifting element connected between the pump body and the first bearing box, the lifting element configured to lift the first bearing box; and a buffer element arranged between the impeller assembly and the inner wall of the pump body and on one side of the bearing, the buffer element configured to buffer the impeller assembly and the bearing. The two sides of the impeller assembly and the inner wall of the pump body form a flow resistance cavity and a cover cavity, respectively, and when the impeller assembly rotates, the hydraulic pressure generated by the medium in the flow resistance cavity on the impeller assembly and the hydraulic pressure generated by the medium in the cover cavity on the impeller assembly reach a balance. The pump body comprises:

2. The multistage pump with higher stability and reliability according to claim 1, characterized by a water inlet section, an outlet corresponding to an inducer; a water outlet section having a pressure relief cavity; a balance pipe, two ends of which are respectively communicated with the water inlet section and the pressure relief cavity; a middle section assembly, two ends of which are respectively communicated with the water inlet section and the water outlet section, and the impeller assembly is arranged on the inner wall of the middle section assembly; a balance drum mounted on the pump shaft; and a balance ring mounted on the water outlet section, the balance ring being spacedly sleeved on the outer wall of the balance drum; The impeller assembly comprises a first impeller, a second impeller and a third impeller, the third impeller is close to the water outlet section, and the cover cavity corresponding to the third impeller is communicated with the pressure relief cavity through the gap between the balance drum and the balance ring; the middle section assembly has a flow discharge cavity corresponding to the side wall of the first impeller and the side wall of the second impeller, the flow discharge cavity and the cover cavity are separated by a friction ring and a friction surface, the flow discharge cavity is communicated with the suction inlet of the first impeller and the suction inlet of the second impeller, the first impeller and the second impeller form a flow discharge channel between them and the pump shaft, the flow discharge cavity is communicated with the suction inlet of the first impeller through the flow discharge channel, the third impeller, the balance ring, the outer friction ring, the inner friction ring, the balance drum and the pump shaft form a balance cavity therebetween, the balance cavity and the cover cavity are separated by the outer friction ring and the inner friction ring, and the balance cavity is communicated with the pressure relief cavity through the gap between the balance drum and the balance ring. The middle section assembly comprises:

3. The multistage pump with higher stability and reliability according to claim 2, characterized by a first middle section, the inner wall of which has a first flow channel surface configured to form a first flow resistance cavity with the outer wall of the impeller assembly; a second middle section mounted on the outlet of the first middle section, the second middle section having a second water pressure flow channel and a second suction flow channel communicated with each other, and the second water pressure flow channel being communicated with the first middle section; and a third middle section mounted on the outlet of the second middle section, the third middle section having a third water pressure flow channel, a third suction flow channel and a fourth water pressure flow channel communicated with each other, and the third water pressure flow channel being communicated with the second suction flow channel. ​ The second pressure water flow channel, the third pressure water flow channel and the fourth pressure water flow channel are configured to convert fluid kinetic energy into pressure energy, and the second suction flow channel and the third suction flow channel are configured to eliminate residual circulation of fluid. The second middle section is provided with a plurality of second middle sections and is sequentially connected, the second middle section comprises a second shell, a second guide vane, a second positive guide vane and a second reverse guide vane, the second guide vane is arranged in the second shell, the second positive guide vane and the second reverse guide vane are connected between the second guide vane and the second shell, the second shell, the second positive guide vane and the second guide vane form the second pressure water flow channel, the second shell, the second reverse guide vane and the second guide vane form the second suction flow channel, the inner wall of the second shell has a second flow channel surface, the second flow channel surface and the impeller assembly form a second flow blocking cavity, and the second guide vane close to the side wall of the first middle section has a second spring mounting groove. The third middle section comprises a third shell, a third guide vane, a third positive guide vane and a third reverse guide vane, the third guide vane is arranged in the third shell, the third positive guide vane and the third reverse guide vane are connected between the third guide vane and the third shell, the third shell, the third positive guide vane and the third guide vane form the third pressure water flow channel, the third shell, the third reverse guide vane and the third guide vane form the third suction flow channel, the third middle section comprises a fourth positive guide vane and a reverse guide vane, the reverse guide vane is arranged on the side of the third shell away from the third reverse guide vane, the reverse guide vane is connected with the third shell through the fourth positive guide vane, the third shell, the fourth positive guide vane and the reverse guide vane form a fourth pressure water flow channel, the inner wall of the third shell has a third flow channel surface, the third flow channel surface and the impeller assembly form a third flow blocking cavity, and the third guide vane close to the side wall of the second middle section has a third spring mounting groove.

4. The multistage pump with higher stability and reliability according to claim 2, characterized by The water inlet section, the middle section assembly and the water outlet section are connected through the stabilizing rod.

5. The stable and highly reliable multi-stage pump according to claim 1, characterized by The first bearing box has a first boss, the first boss is installed in the first positioning groove, the first boss has a first mounting threaded hole, and the first mounting threaded hole is arranged above the first positioning counterbore; The multi-stage pump comprises: The first heat exchange seat has a first positioning groove and a first positioning counterbore arranged at the bottom of the first positioning groove; The second first heat exchange seat has a second positioning groove and a second positioning counterbore arranged at the bottom of the second positioning groove; and The second bearing box has a second boss, the second boss is installed in the second positioning groove, the second boss has a second mounting threaded hole, and the second mounting threaded hole is arranged above the second positioning counterbore; The lifting amount component comprises: A first lifting amount bolt is threadedly connected to the first mounting threaded hole, and the bottom of the first lifting amount bolt abuts against the first positioning counterbore; and A second lifting amount bolt is threadedly connected to the second mounting threaded hole, and the bottom of the second lifting amount bolt abuts against the second positioning counterbore. The first lifting bolt is screwed to lift the first bearing box, and the second lifting bolt is screwed to lift the second bearing box. The first bearing box and the second bearing box are configured to mount a pump shaft.

6. The multistage pump with higher stability and reliability according to claim 5, characterized by The first boss has a first mounting counterbore above the first mounting threaded hole, and the head of the first lifting bolt is located in the first mounting counterbore. The second boss has a second mounting counterbore above the second mounting threaded hole, and the head of the second lifting bolt is located in the second mounting counterbore. The lifting piece comprises: A first locking nut, the first boss has a first stop threaded hole above the first mounting counterbore, the first locking nut is threadedly connected to the first stop threaded hole, and abuts against the head of the first lifting bolt; A first stop nut, which is threadedly connected to the first stop threaded hole and is located above the first locking nut; A first stop washer, which is arranged in the first stop threaded hole, is located between the first locking nut and the first stop nut, and the first boss has a first stop groove passing through the first stop threaded hole. One end of the first stop washer extends horizontally out of the first stop groove and is bent downward to fit the side wall of the first boss away from the first positioning groove; A second locking nut, the second boss has a second stop threaded hole above the second mounting counterbore, the second locking nut is threadedly connected to the second stop threaded hole, and abuts against the head of the second lifting bolt; A second stop nut, which is threadedly connected to the second stop threaded hole and is located above the second locking nut; and A second stop washer, which is arranged in the second stop threaded hole, is located between the second locking nut and the second stop nut, and the second boss has a second stop groove passing through the second stop threaded hole. One end of the second stop washer extends horizontally out of the second stop groove and is bent downward to fit the side wall of the second boss away from the second positioning groove.

7. The stable and highly reliable multi-stage pump according to claim 1, wherein The pump body has a guide vane, the side wall of the guide vane has a first mounting groove, the impeller assembly close to the side wall of the guide vane has a friction surface, the inner wall of the first bearing box has a second mounting groove, the bearing is arranged in the second mounting groove, and the buffer piece comprises: A first spring arranged in the first mounting groove; A friction ring, one side of which is arranged in the first mounting groove and connected with the spring, and the other side of which extends out of the first mounting groove and abuts against the friction surface; and A second spring arranged in the second mounting groove, one end of which abuts against the bearing. The bearing is mounted on the outer peripheral wall of the pump shaft, and one end of the second spring abuts against the bearing.

8. The multistage pump with higher stability and reliability according to claim 7, characterized by, The first spring and the second spring are both corrugated springs, the bearing is an angular contact ball bearing, the side wall of the guide vane has two first mounting grooves, the two first mounting grooves are respectively located at the upper portion and the lower portion of the friction ring, the axial direction of the friction ring coincides with the axial direction of the impeller, the compression stroke of the first spring is a, and the thickness of the friction ring extending out of the first mounting groove when the first spring is not subjected to force is b, and a < b.

9. The stable and highly reliable multi-stage pump according to claim 1, wherein The outer peripheral wall of the pump body is sleeved with a cylinder body, a first heat exchange cavity is formed between the cylinder body and the pump body, and the first heat exchange cavity is configured to input or output a heat exchange medium; The multi-stage pump comprises: A first heat exchange seat is installed on the side of the first bearing box away from the pump body, the pump shaft is rotatably installed on the first heat exchange seat, the first heat exchange seat has a second heat exchange cavity, and the second heat exchange cavity is configured to input or output a heat exchange medium; A second heat exchange seat is installed on one end of the pump body, the pump shaft is rotatably installed on the second heat exchange seat, the second heat exchange seat has a third heat exchange cavity, and the third heat exchange cavity is configured to input or output a heat exchange medium; and A third heat exchange seat is installed on the other end of the pump body, the pump shaft is rotatably installed on the third heat exchange seat, the third heat exchange seat has a fourth heat exchange cavity, and the fourth heat exchange cavity is configured to input or output a heat exchange medium.

10. The stable and highly reliable multi-stage pump according to claim 9, characterized by, The vibration sensor is installed on the first bearing box, and the temperature sensor is provided with a plurality of temperature sensors and is respectively installed on the first heat exchange cavity, the second heat exchange cavity, the third heat exchange cavity and the fourth heat exchange cavity.

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