RU2773263C1 - Multiphase vane pump - Google Patents

Abstract

FIELD: pumping technology.

SUBSTANCE: invention relates to vane machines, namely to the design of multiphase vane pumps designed for pumping petroleum products and gas-liquid mixtures. A multiphase vane pump reduces pressure losses in the supply due to a decrease in hydraulic resistance at the entrance to the helico-axial flow part by switching to a sectional pump circuit, which is possible due to the inlet housing 1 with a receiving flange nozzle 2 to be performed with a spacer and with a smooth transition to the annular space of the supply having at least one radial rib. The installation of the rib prevents the flow from swirling at the entrance to the flow part of the impeller of the first stage. To equalize the flow velocity field and reduce the negative effect of reverse currents, the ends of the blades on the impeller of the first stage have a groove along the cone with a decrease in the outer diameter of the blades from the input to the output section at a constant size of the sleeve. The joint of the spacer ring with the sealing ring of the first stage is made with a larger diameter along the sealing ring and smaller, respectively, along the spacer ring.

EFFECT: these features make it possible to improve anti-cavitation characteristics and reduce energy consumption during pump operation.

10 cl, 8 dwg

Description

The invention relates to vane machines, and in particular to the design of multiphase vane pumps designed for pumping oil products and gas-liquid mixtures, such as oil well products, including in compressor mode.

Known screw-centrifugal pump, consisting of a supply with an inlet pipe, an upstream axial wheel, a centrifugal wheel, a spiral collector at the outlet of the centrifugal wheel, a conical diffuser, an outlet pipe, sealing elements with "floating" rings, a sealing element with an impeller (High-speed vane pumps / / Under the editorship of Doctor of Engineering Sciences B.V. Ovsyannikov and Doctor of Engineering Sciences V.F. Chebaevsky - M.: Mashinostroenie, 1975. - 336 p.).

The main disadvantage of the screw-centrifugal pump is the limitation on the content of free gas in the pumped liquid - no more than 30÷34%.

Known compressor containing a housing in which a rotor is installed, having a thrust bearing with pads mounted on elastic plates. The compressor also has a device for unloading the thrust bearing from axial forces, including an unloading piston and a cavity communicated with the compressor suction cavity by means of a line with a control valve. The bearing has a sensor for measuring the deflection of elastic plates (AS SU 903570, IPC F01D 3/04, F01D 25/16, F01D 29/04, publ. 02/07/1982).

The main disadvantage of the known design is a large error in the regulation of the force applied to the bearing, due to the influence of the variation in the mechanical characteristics of the plate material, the effect of thermal expansion on the structure, which affects the deflection of the plates, and the complexity of debugging the control system under operating conditions.

A pump for transporting a fluid with varying viscosity is known (patent RU 2703164, IPC F04D 7/02, F04D 29/041, publ. 10/16/2019), which can be made in the form of a multiphase pump. The pump has a housing with an inlet and outlet for the fluid to be transported, as well as at least one impeller for moving the fluid from the inlet to the outlet, the impeller being placed on a rotating shaft, as well as a balancing drum for relieving axial pressure . The balancing drum comprises a rotor rotatably connected to the shaft, wherein the rotor has a high pressure side and a low pressure side. A stator fixed in relation to the housing and a relief passage that runs between the rotor and the stator from the high pressure side to the low pressure side of the rotor. At the same time, a return channel is additionally made, which connects the low pressure side of the rotor with the inlet. In addition, at least one intermediate channel is provided that opens into a discharge channel between the high pressure side and the low pressure side of the rotor, wherein a blocking element is provided to influence the flow through the intermediate channel.

The disadvantage of analogue is the inertia of the unloading system with flow control passing through the working gap between the balancing drum and the stator, using a blocking device (for example, an electric valve) under operating conditions, the distinguishing feature of which is a strong pressure pulsation in the flow. Such conditions always occur when pumping gas-liquid mixtures and mixtures of mutually insoluble liquid media with different densities (AI Guzhov - Joint collection and transport of oil and gas. - M.: Nedra, 1973-280 S.).

Helical-axial multiphase pumps are known (https://sulzer.nt-rt.ru/images/manuals/mnogofru.pdf).

Known multiphase pump https://www.sulzer.com/-/media/files/products/pumps/multiphase-pumps/brochures/mpp_high_performance_multi_phase_pump_e00601.ashx?la=ru-ru).

Taken as a prototype.

Said pump contains an outer casing in the form of a pipe with inlet and outlet nozzles, an inner casing with a horizontal split, a perforated cylindrical section at the inlet to the helico-axial multi-stage flow part, consisting of a stator with guide vanes and over-rotary rings in the inner casing and from a rotor with cylindrical groove along the outer diameter of the blades by impellers on a shaft supported by radial plain bearings in the housings of the front support - on the side of the intake pipe, and the rear support - on the side of the discharge pipe, which are separated from the helical-axial flow part by end seals, and one of the ends The shaft is made for the installation of the drive coupling half, while the rotor is fixed in the axial direction by a self-aligning segmental thrust bearing, the housing of which is attached to the rear support housing.

The disadvantages of the prototype are as follows:

1. High hydraulic resistance of the perforated cylindrical section at the inlet to the flow part of the pump.

2. Insufficient suction capacity of the first stage impeller due to insufficient measures to prevent flow swirling at the inlet of the pump flow path.

3. Insufficient reliability of the thrust plain bearing with self-aligning segments due to high circumferential velocities on the sliding friction surfaces (about 70 m/s), high operating costs and maintaining the efficiency of the thrust plain bearing and the storage and preparation systems associated with this bearing.

4. The high cost of the pump due to the low technology of the outer and inner casings of the pump and the lack of the possibility of their use for pumps of other sizes in terms of flow and pressure.

The technical problem solved by the invention is the creation of a multi-phase vane pump, devoid of the disadvantages of analogues, with improved anti-cavitation characteristics, increased energy efficiency, reliability and manufacturability, respectively, increased resource and service life.

The technical result is an increase in the reliability and efficiency of the multiphase vane pump.

The problem is solved, and the technical result is achieved by a multiphase vane pump with a horizontal axis, containing a housing with intake and discharge pipes, a helical-axial multistage flow part of the housing, consisting of a stator with guide vanes and over-rotor rings and a rotor with impellers having a cylindrical groove along the outer diameter of the blades, while the impellers are mounted on a shaft supported by radial plain bearings in the housings of the front and rear supports from the side of the inlet and outlet pipes, respectively, and these supports are separated from the helico-axial flow part by end seals, and one of the ends of the shaft is made for the installation of the drive coupling half. In contrast to the prototype , the body is made composite and includes an inlet body with a suction pipe, an outlet body with an outlet pipe and sections in the form of rings located between said bodies, while the bodies and sections are tightened around the periphery, and the sections in the form of rings are made with flanges along the inner diameter for each stage of the flow part, to which guide vanes and over-rotary sealing rings with axial connectors are fixed, and in the flow part of the inlet body there is a hydraulic seal cavity separated from the flow part by the body, in which the corresponding end seal is located, and a spacer ring for supplying flow to the blades of the working wheels of the first stage, while the flow part of the inlet body is made with a smooth transition from the inlet pipe to the inlet annulus, having at least one radial fin installed in the direction of flow, and in the circumferential direction the axis of the fin is located at an angle of 200-250° from receiving stalemate axis cabin in the direction of rotation of the pump rotor, and the joint of the spacer ring with the sealing ring of the first stage is made with a large diameter along the sealing ring and a smaller one, respectively, along the spacer, in addition, the pump includes an unloading system consisting of an unloading cavity and end impeller rings mounted on the rotor shaft and unloading drum located in the annular space of the outlet body and having a pressed unloading sleeve forming a slotted seal with the drum, the unloading cavity being formed by the unloading body fixed to the outlet body from the side of the rear support of the rotor, and connected to the hydraulic seal cavity and further to the flow part of the inlet body through at least one auxiliary pipeline, and the ends of the blades on the impeller of the first stage have a groove along the cone with a decrease in the outer diameter of the blades from the inlet to the outlet section at a constant size of the impeller hub, while the rear The rotor support for fixing the rotor in the axial direction includes a “floating” assembly of radial-thrust or thrust rolling bearings in a separate housing attached to the housing of the rear rotor support.

In special cases:

- the body of the hydraulic seal cavity has a smooth transition from the surface of the flow part of the inlet body, and in relation to the flow part of the bushing surface of the impeller disk of the first stage, the transition is made stepwise towards lowering the inlet flow diameter of the impeller disk and with a smooth entry due to the rounding of the corner at the inlet end disk, while the cavity of the hydraulic seal is communicated with the flow part by means of a slotted seal formed by the body of the cavity of the hydraulic seal and the bushing of the hydraulic seal on the rotor;

- the spacer ring is made separately from the inlet housing in the form of an independent part, separated from the flow part, while on the side of the flow part it has a smooth transition to the conical surface of the first stage sealing ring, and the joint of the spacer ring with the first stage sealing ring is stepped, that is, the value the diameter of the spacer ring is less than the diameter of this sealing ring by 0.8 ... 1.6 mm or more, with a smooth exit to the flow surface of the sealing ring, that is, the diameter of the spacer ring at the junction with the first stage sealing ring is guaranteed to be less than the diameter of the first stage sealing ring, moreover, the specified joint is made with a gap;

- mechanical seals of double or tandem type are made for sealing the pump shaft, installed on the inlet housing and the discharge housing, respectively;

- the housing of the front rotor support on the input side is mounted on the half-flange of the bracket of the input housing, and the housing of the rear rotor support on the output side is mounted on the half-flange of the discharge housing;

- the sealing ring of the first stage, covering the impeller of the first stage, is made conical with the provision of a radial clearance along the ends of the impeller blades;

- the bearing assembly consists of an outer housing, which is hermetically fixed to the housing of the front rotor support, forming a single cavity with the cavity of the rear rotor support, and inside the cylindrical opening of the outer housing with a gap, a rolling bearing housing with a sealed cover is installed, and this gap is sealed from the ends with rubber rings, the rolling bearings are installed in the housing along the outer diameter, they are also seated and fixed on a single bushing according to the inner diameter, which is seated with a radial clearance on the shaft spike from the output side and fixed in the axial and circumferential directions with the help of a nut and a keyway, respectively, at the same time, the mutual axial fixation of the rolling bearing housing and the outer housing is made using a bracket fixed on the outer housing and a central bolt resting on the bracket and screwed into the sealed cover of the rolling bearing housing, the sliding bearings being provided with oil rings;

- over the ends of the blades of the impellers in the case when the outer diameter of the ring of the end impeller is less than the diameter of the ends of the blades of the rotor impellers, one-piece over-rotary sealing rings are installed;

- a “floating” assembly of angular contact or thrust rolling bearings in the housing is fixed in the axial direction by a central bolt resting on a rigidly fixed bracket and screwed into the sealed cover of the rolling bearing housing, and to monitor the residual axial force on the rotor, a a measuring device in the form of a primary piezometry sensor;

- housings and sections are tightened around the periphery with pins located outside the flow path.

The technical result is achieved by the presented set of essential features.

The graphic material contains one of the possible designs of a multiphase vane pump that meets the essence of the present invention:

fig. 1 - view of the pump from the drive side (inlet housing);

fig. 2 - view of the pump from the drive side (outlet casing);

fig. 3 - longitudinal section of the pump along A-A;

fig. 4 (view B) - an enlarged scale of the longitudinal section of the inlet housing (flow path);

fig. 5 (section B-B) - pump inlet in a plane transverse to the axis of rotation and along the axis of the intake pipe on an enlarged scale;

fig. 6 (view F) - entrance to the impeller of the first stage of the flow part on an enlarged scale;

fig. 7 (view K) - an enlarged scale of the angular contact bearing assembly with a piezoelectric axial force meter on the rotor;

fig. 8 (section C-C) - entrance to the lower auxiliary pipeline (discharge pipe) in a section perpendicular to the axis of rotation, on an enlarged scale;

fig. 9 (a, b) - shows the triangles of flow rates at the inlet to the blades of the impeller of the 1st stage, a) - axial flow inlet, b) - flow swirling in the direction of rotation of the impeller of the 1st stage of the rotor.

The figures indicate:

1 - entrance body

2 - supporting paws of the input body

3 - intake pipe

4 - output housing

5 - supporting paws of the output body

6 - discharge pipe

7 and 8 - auxiliary pipelines (unloading tubes) for connecting the unloading cavity with the flow part of the inlet part of the housing

9 - hydraulic seal body

10 - hydraulic seal bushing

11 - spacer ring for forming the flow supply to the blades of the impeller (RK) of the first stage

12 - section of the annular section of the first stage

13 - nadrotorny ring of the RK of the first stage

14 - guide vanes of the first stage

15 - intermediate stage section

16 - nadrotorny ring of the intermediate stage

17 - intermediate stage guide vane

18 - section of the last stage

19 - nadrotorny ring of section 18

20 - guide apparatus of the last stage

21 - unloading sleeve, pressed into the output housing 4

22 - unloading body

23 and 24 - tandem mechanical seals for pump shaft seal

25 and 26 - the upper and lower half of the pump bearing housing, respectively, from the inlet and outlet sides

27 - radial plain bearing

28 - oil rings

29 - fitting for oil supply from an external oil system

30 - outer housing of the angular contact bearings

31 - rolling bearing housing

32 - thrust bearing

33 - oil supply nozzles

34 - sleeve

35 - thrust adjusting washer

36 - bearing sleeve

37 - bushing nut 36

38 - nut lock

39 - bearing housing housing

40 - power bolt

41 - bracket

42 - primary strain gauge sensor

43 - shaft for installing impellers

44 - key for the half-coupling of the pump drive

45 - first stage impeller

46 - intermediate stage impellers

47 - impeller of the last stage

48 - unloading drum

49 and 50 - threaded fittings

51 and 52 - fittings

53 - power studs

54 - nuts

55 - outlet pipe flange

56 - fitting for oil supply,

57 - shims

58 and 59 - fasteners for fixing the bearing housing

60 - bushings of interstage slotted seals

61 - end impeller

62 - nut for tightening the end impeller ring on the shaft 61

63 - rubber seals of housings 31 of rolling bearings

64 - key from rotation of the sleeve 36 bearings.

In addition, the drawings indicate:

P - flow part of the input housing 1;

H - two holes in the body of the input housing 1;

G - cavity of the water seal;

I - unloading cavity;

B1 - flow surface of the body 9 of the water seal;

R1 - chamfer rounding radius at the input of the RC bushing;

R2 - chamfer rounding radius at the inlet of the over-thrust ring;

M - redan at the inlet of the impeller bushing;

G1 - gap between the end surfaces of the valve body and the body 9 of the hydraulic seal, which provides compensation for thermal expansion of the pump parts;

Zh - the size that allows for the installation and dismantling of the pump without touching the unloading tube with 8 parts and assembly units of the unit;

L - redan at the entrance of the supra-torque ring;

D1 - gap between the end surfaces of the supratoneal ring 13 and the spacer ring 11, which provides compensation for thermal expansion of the pump parts;

С, Ш, Ш - flanged bolted connection along a flat axial connector of guide vanes 14, 17 and 20, respectively;

Y - milling along an arc with a radius R3, ending with a protrusion B1;

E and Y - threaded holes of the centering pins to the half-flange of the inlet housing bracket;

Yu and I - threaded holes to the semi-flange of the bracket of the body 22 of the unloading.

The inventive pump works as follows.

Installation sequence.

The inlet body 1 is assembled on the slipway with the installed body 9 of the hydraulic seal. The intake pipe 3 smoothly passes into the annular space of the flow part, in which at least one radial rib is made, installed in the direction of flow, and the output edge of the rib should preferably be located at a distance of at least two to three heights of the leading edge of the blade with respect to the impeller of the first stage wheels, the bevel of the outlet edge of the rib from the side of the pump axis is allowed, and in the circumferential direction the axis of the rib is preferably at an angle of about 225° from the axis of the suction pipe in the direction of rotation of the pump rotor. The inlet body 1 has two holes and, accordingly, two threaded fittings for connecting auxiliary pipelines (discharge pipes), as well as a flange connection with bolts to the hydraulic seal body.

From the side of the mating plane of the inlet housing 1, the following are installed in series:

- spacer ring 11 with tight pressing against the mating plane of the inlet body (the spacer ring can be made separately from the inlet body in the form of an independent part, as in Fig. 3, item 11);

- a balanced rotor with a shaft 43 and a bushing 10 of a hydraulic seal installed on it, impellers 45, 46 and 47, bushings 60 of interstage seals with rubber seals along the shaft, an end impeller ring 61 and an unloading drum 48, tightened on the shaft by a nut 62 with subsequent locking, in this case, the shaft 43 is mounted on technological supports coaxially with the cover of the inlet part 1 and the spacer ring 11; the unloading system consists of the end impeller ring 61 mounted on the rotor shaft, the drum 48 and the unloading sleeve pressed into the outlet cover, which forms a slotted seal with the drum, the leaks of which during pump operation are discharged into the unloading cavity formed by the unloading housing;

- section 12 of the first stage with tight pressing against the mating plane of the spacer ring 11, to which the sealing ring 13 and the guide vane 14 of the first stage are bolted, while the flat axial connector on the guide vanes is mounted with a rotation of 90 ° with respect to the connector of the already installed sealing ring 13, and the joints of the horizontal connectors of the sealing ring 13 and the guide vane 14 of the first stage are covered with a sealant before assembly; above the ends of the blades of the impellers in the case when the outer diameter of the ring of the end impeller is less than the diameter of the ends of the blades of the impellers of the rotor, one-piece sealing rings are installed;

- the position of the section 12 of the first stage is fixed by a technological jack, while due to the vertical regulation, the uniformity of the gaps in the circumferential direction between the ends of the blades of the impeller 45 of the first stage and the sealing ring 13 is ensured, and along the interstage seal of the first stage;

- the position of the rotor in the axial direction is checked and, if necessary, set in the axial direction along the gap between the ends of the impeller 45 of the first stage and the sealing ring 13, while dimension A1 is fixed and entered in the accompanying documentation from the end of the shaft 43 on the drive side to the end of the bracket on the input part 1 of the housing (see Fig. 3);

- similarly to the assembly of the section 12 of the first stage, the sections 15 of the intermediate stages are mounted with sealing rings 16 and the guide vanes 17 of the intermediate stages, and the section 18 of the last stage with the sealing ring 19 and the guide vane 20 of the last stage;

- to the section 18 of the last stage, the output part 4 of the body, which must be installed on the slipway and pressed against it, is closely attached and pressed with the appropriate mating surface;

- the section of each stage assembly includes the section itself in the form of a steel ring, to which a sealing ring and a guide vane are attached from the inside by means of a flange connection, the half rings of which are joined along a flat axial connector, and the guide vane is mounted with a rotation of 90 ° with respect to a flat connector of an already installed sealing ring; wear-resistant coating is applied on the working surfaces of the sealing rings, and the joints of the flat axial connectors of the sealing rings and guide vanes can be coated with a sealant before final assembly;

- studs 53 are installed and tightened with nuts 54 to the moment specified in the design documentation for the pump. During the assembly process, the gap between the unloading sleeve 21 and the drum 48 must be controlled and ensured with the help of jacks, and the rotation of the rotor on technological supports should be smooth without jamming. After the final tightening of the nuts 54, the technological jacks are retracted, the size A1 is checked;

- mechanical seals 23 and 24 are mounted, the pressing of the contact rings of which is weakened for the time of further installation of the pump;

- the lower halves of bearing housings 26 are installed on the pump inlet and outlet sides, oil rings 28 and the lower halves of plain bearings 27 are installed, the surfaces of which are lubricated with process grease. The rotor shaft is placed on its own plain bearings 27, in the absence of rotation of the rotor, the preliminary centering of the rotor is carried out by leveling the position of the housing halves 26 of the pump bearings with adjusting bolts installed in the threaded holes S, E, Yu, I; the bearing unit consists of an outer housing, which is hermetically attached to the housing of the front rotor support, forming a single cavity with the cavity of the rear support of the rotor, and inside the cylindrical opening of the outer housing with a gap, a housing of rolling bearings with a sealed cover is installed, and this gap is sealed from the ends with rubber rings , which allows, due to the elastic radial movement, to compensate for the misalignment of the shaft, in addition, oil is supplied to the housing of the rolling bearings for lubrication and cooling of the bearings, which is then removed by gravity through the cavity of the rear support of the rotor, and in addition, the rolling bearings are installed in the housing along the outer diameter , they are seated and fixed on a single sleeve according to the fitting inner diameter, which with a radial clearance sits on the shaft spike from the output side and is fixed in the axial and circumferential directions with the help of a nut and a key connection, respectively, and as for the mutual axial fixation of the rolling bearing housing and outer housing, then it is made using a bracket fixed on the outer housing and a central bolt resting on the bracket and screwed into the sealed cover of the rolling bearing housing;

- the clearances in the plain bearings are checked and, if necessary, improved, the upper halves of the 25 bearing housings are installed on the pump inlet and outlet sides. The rotor is centered in order to ensure ease of rotation by leveling the position of the halves of 26 pump bearing housings with adjusting bolts, technological supports are retracted; a measuring device is installed on the cylindrical section of the central bolt resting on the bracket and screwed into the sealed cover of the rolling bearing housing to monitor the residual axial force on the rotor (for example, in the form of a primary piezometric sensor, the signal of which is used in the automated control system, for example, to block the operation of the pump according to the setting in case of exceeding the permissible value of the signal of the residual axial force on the rotor);

- after completion of the adjustment of the position of the rotor, the bearing housings are fixed with pins and fasteners 58 and 59, the adjusting bolts are dismantled, the upper covers of the rotor support housings are mounted, the mechanical seals 23 and 24 are brought into working condition. Preliminary or acceptance testing of the pump is being prepared and carried out.

Under the operating conditions of the pump, the processes of stopping and starting the pump are usually automated, however, the initial commissioning of the pump is accompanied by commissioning and related checks of the performance of all systems of the pump unit, including the automated control system.

The inventive pump is driven by an electric motor through a drive clutch, a step-up gearbox, or without a gearbox in the case of a high-speed engine.

In the process of operation, one or another refined product is supplied to the pump inlet, and in the case of pumping a gas-liquid mixture (hereinafter referred to as GZhM), a previously prepared GZhM in terms of smoothing pulsations and free gas content (hereinafter referred to as the pumped medium). In the pump, the pumped medium passes from the branch pipe 3 into the annular zone P of the inlet housing 1, is redistributed throughout the entire volume P and, thanks to the installation of a radial rib directed along the axis, ends up at the inlet of the impeller 45 of the first stage with a minimum circumferential component of the absolute flow velocity. The conical shape of the periphery of the impeller blades of the first stage and the stepped design of the transitions from the spacer ring 11 to the sealing ring 12 with a smooth entry, as well as smooth transitions from the body 9 of the hydraulic seal to the bushing surface of the impeller disc 45 of the first stage, contribute to minimizing hydraulic losses.

When the pump rotor rotates, mechanical energy is converted into hydraulic energy by means of impellers 45, 46 and 47, as well as guide vanes 14, 17 and 20 working with them. environment. The pumped medium under pressure, with an axial and circumferential component of absolute velocity, under the influence of the reaction from the ring of the end impeller 61 is directed into the annular space and the discharge pipe 6 of the housing 4, partly into the unloading device, and above all into the gap between the unloading sleeve 21 and the housing 22 unloading.

During operation, with an increase in the pressure of the pumped medium, the dynamic resistance of the pumped medium, which falls on the blades of the impellers, and the pressure drop on the elements of the pump rotor increase, which cause the appearance of an axial force on the rotor transmitted to the shaft 43. To compensate for the main part of the axial force in the pump, a drum-type unloading device (see Fig. 3), consisting of a discharge sleeve 21, a drum 22, an unloading cavity And connected by a hydraulic unloading cavity G by unloading tubes 7 and 8, and openings H in the body of the inlet cover of the housing part 1, and then by means of gap seal B1 with cavity П of the flow part of the inlet body.

The used drum-type unloader is a typical solution among the known dynamic pumps and ensures operation in conditions of vaporization, on GLS and gas, provides unloading in almost all modes, while complete unloading of the axial force on the rotor takes place in one of the selected modes, for example, in nominal or maximum. To balance the residual axial forces in the inventive pump, a thrust bearing is used, the residual axial force is transmitted by the shaft 43 to the node of the angular contact bearings 32, the node of which is made "floating".

The use of the proposed device has the following advantages:

1. Allows you to reduce pressure losses in the supply due to a decrease in hydraulic resistance by switching from a double-casing pump scheme - a prototype to a sectional one and replacing the perforated cylinder with an inlet casing 1 with a receiving flange pipe 3, smoothly passing through the flow part into the annular space G of the supply, having, at least one radial rib P installed in the direction of flow, and in the circumferential direction the axis of the rib P is at an angle of 200÷250° from the axis of the inlet pipe H in the direction of rotation of the pump rotor.

The pump inlet is similar to the design recommended for axial pumps (High-speed vane pumps. - Edited by Dr. Tech. Sciences B.V. Ovsyannikov and Dr. Tech. Sciences V.F. Chebaevsky. - M .: Mashinostroenie, 1975 . - 336 s.), while the energy loss in the supply L _sub. with a branch pipe with a diameter D _in , referred to the flow rate c ₁ in the section (0.3 ÷ 0.4) _{⋅D in} , will be L _sub. =ξ _sub. ⋅ s ₁ ² /2 (ibid. on p. 21), where the supply resistance coefficient ξ _sub. =0.75÷1. For comparison, the hydraulic resistance of a perforated cylinder can be estimated from the hydraulic resistance of similar elements (grids, grids, etc.), which are installed at the pipe inlet as filters and other things (Gorlin S.M. - Experimental aeromechanics. - Textbook for universities. - M .: Higher school, 1970. - 423 p.), while the pressure loss of the elements depends on the ratio F ₀ /F ₁ \u003d 0.25 ÷ 0.30, where F ₀ is the area of the live section of the perforation, and F ₁ is the cross section the inner diameter of the perforated section of the cylinder, the resistance coefficient of the perforated section will be ξ _sub. =10÷7 (ibid. p. 417, Fig. X16). Thus, the loss of flow energy in the supply, in the inventive pump, will be reduced by 7÷14 times.

2. In the proposed design of the pump, swirling of the flow at the inlet is prevented by installing a rib in the longitudinal direction of the flow path. The swirl of the flow at the inlet of the axial wheel is impractical (High-speed vane pumps. - Edited by Dr. Tech. Sciences B.V. Ovsyannikov and Dr. Tech. Sciences V.F. Chebaevsky. - M .: Mashinostroenie, 1975. - 336 pp., p. 166), so the analysis of the velocity triangles at the input of the axial wheel for the case with flow swirl (“a” in Fig. 9) and axial input (“b” in Fig. 9) shows that in order to maintain the same the same feed, that is, the axial component of the speed with _1z = Сonst, for scheme "a" with swirl of the flow, an increase in the number of revolutions of the rotor is required. This explains the effect of flow swirl on stall cavitation characteristics and the corresponding restriction on suction capacity. In centrifugal pumps for the oil industry, to increase the suction capacity, the impellers of the 1st stage are made with an expanded inlet area (Mikhailov A.K., Malyushenko V.V. - Design and calculation of high pressure centrifugal pumps. - M .: Mashinostroenie, 1974. - pp. 276-277).

The suction capacity of dynamic pumps is closely related to stall cavitation characteristics. Studies of screw-centrifugal pumps have shown that the experimental points obtained when testing on a gas-liquid mixture are well averaged by the experimental dependence obtained when testing the same pump on a single-phase liquid (High-speed vane pumps. - Edited by Dr. Tech. Sciences B.V. Ovsyannikov and Doctor of Technical Sciences V.F. Chebaevsky - M.: Mashinostroenie, 1975. - 336 pp., pp. 250-251). The anti-cavitation properties of a screw-centrifugal pump are determined by the upstream screw, which is an axial stage, therefore, the cavitation characteristics for a helical-axial pump can be determined from the results of tests on a single-phase liquid. The positive effect of using the first stage with an expanded inlet area on oil centrifugal pumps can also be used in axial stages (ibid., p. 38). To equalize the velocity field behind the impeller of the first stage of the pump in the proposed invention, the wheel is made with a groove along the cone with a decrease in the outer diameter of the blades from the inlet to the outlet section with a constant bushing size - this is also consistent with the recommendations (ibid., p. 38), and for to reduce the negative effect of reverse currents on the wheel 45 of the first stage, a stepped joint of the spacer ring 11 with the sealing ring 13 of the first stage is made, made with a larger diameter along the sealing ring 13 and a smaller one, respectively, along the spacer ring 11.

3. Comparative design evaluation of the technical and energy efficiency of systems for balancing axial forces arising during the operation of a multiphase vane pump, namely, a pump thrust bearing - a prototype of a variable direction of action (hereinafter - option 1) on the one hand, and an alternative technical solution of the present invention, including the use of a drum-type unloader in conjunction with an assembly of angular contact rolling bearings (hereinafter - option 2), on the other hand, with the same axial load and pump rotor speed, showed the following results:

a) in terms of energy efficiency:

- the main share of power losses in option 1 is due to overcoming the resistance to rotation of the disk of the thrust bearing with self-aligning segments with a lubricating viscous layer on the working surfaces, the proportion of these losses is more than 90%, taking into account the energy costs for cooling the lubricating oil, the rest of the power losses are related to pumping and supply of lubricating oil to/on the thrust plain bearing;

- the main share of power losses in option 2 is due to leakage of the medium pumped by the pump through the working gap of the drum 48 of the unloader (see Fig. 3), the cavity I of which is connected to the cavity of the hydraulic seal G and the pump inlet using discharge tubes 7 and 8, and also overcoming the resistance of the viscosity of these leaks to the rotation of the drum 48, while the total share of the power of these losses is about 85%, taking into account the case of pumping a liquid with a viscosity of about 25 cSt with a local increase in temperature not higher than allowed (in the case of pumping a medium containing vapors and free gas, losses to overcome viscosity resistance of leaks to the rotation of the drum drops sharply), in addition, the power loss for the drive of the angular contact bearing assembly, pumping and supplying lubricant will be about 15%,

- in general, the total power losses of the helico-axial pump in option 1 - with a thrust plain bearing and in option 2 - with a drum-type unloading device, jointly used with an assembly of angular contact rolling bearings, do not have big differences;

b) in terms of reliability:

- in option 1, at the number of revolutions of the pump rotor, the circumferential speed at the outer radius of 140 mm of the thrust plain bearing is 73.3 m/s, comparing this value of the circumferential speed with the permissible value according to GOST 1320-74 “Tin and lead babbits. Specifications” showed an excess of the calculated value from the allowable (≤50 m/s) by 50%;

- in option 2, the calculation for the durability of an angular contact bearing 176220 GOST 8995-75 showed that the obtained value is 170554 h >> 40000 h, the latter value being the minimum allowable (Gorlin S.M. - Experimental aeromechanics. - Textbook for universities. - M .: Higher school, 1970. - 423 p.), while the maximum number of revolutions on the helico-axial pump is 5000 rpm, and this value for the angular contact bearing 176220 according to GOST 8995-75 does not exceed admissible value and satisfies the requirements of application in conditions of variable direction of axial forces.

The indicated estimates of the technical and energy efficiency of axial force balancing systems were carried out on the basis of the following methods: Chernavsky S.A. - Plain bearings. - M.: Gosizdat, 1963, 244 p., p. 221-229; Skubachevsky G.S. - Aircraft gas turbine engines. Design and calculation of details. - 5th ed., revised. and additional - M.: Mashinostroenie, 1981, 550 p., p. 467-472.

According to the calculation results, it can be seen that the most preferable variant of the axial force balancing system for a multiphase vane pump is the variant of using a drum-type unloading device in conjunction with an assembly of angular contact rolling bearings.

The claimed design makes it possible to reduce pressure losses in the supply due to a decrease in hydraulic resistance at the inlet to the helical-axial flow part by switching from a double-casing pump scheme - a prototype to a sectional one, which makes it possible to abandon the perforated cylinder (in the prototype), and the inlet casing with a receiving flange pipe with a spacer and with a smooth transition into the annular supply space, which has at least one radial rib. Installing the rib as described prevents swirling of the flow at the inlet to the first stage impeller. In addition, to equalize the field of flow velocities and reduce the negative effect of reverse currents, the ends of the blades on the impeller of the first stage have a groove along the cone with a decrease in the outer diameter of the blades from the inlet to the outlet section at a constant size of the sleeve, while the joint of the spacer ring with the sealing ring of the first stage made with a large diameter along the sealing ring and a smaller one, respectively, along the spacer ring. These features make it possible to improve anti-cavitation characteristics and reduce energy consumption during pump operation.

In addition, a multi-phase vane pump, unlike the prototype, includes a drum-type unloading device together with a “floating” assembly of angular contact rolling bearings (for example, the book Rolling Bearings. Directory-catalog. - Edited by V.N. Naryshkin and R .V. Korostashevsky. - M.: Mashinostroenie, 1984, 280 pp., p. 89) to compensate for the main part of the residual axial force after the unloading device, perceiving the axial force of a variable direction and fixing the rotor in the axial direction, which leads to an increase in the reliability of the system balancing the axial forces of the rotor, since there are no sliding surfaces on the thrust bearing, which is used on the prototype. This will also reduce the oil consumption for cooling the bearings as a whole.

Thus, the inventive pump ensures the reliability and efficiency of pumping oil products and gas-liquid mixtures.

Claims (10)

1. A multiphase vane pump with a horizontal axis, containing a housing with inlet and outlet pipes, a helical-axial multistage flow part of the housing, consisting of a stator with guide vanes and over-torque rings and a rotor with impellers having a cylindrical groove along the outer diameter of the blades, with in this case, the impellers are mounted on a shaft supported by radial plain bearings in the housings of the front and rear supports on the side of the inlet and outlet pipes, respectively, and these supports are separated from the helico-axial flow part by end seals, and one of the ends of the shaft is made for the installation of a drive coupling half, characterized in that the body is made composite and includes an inlet body with a suction pipe, an outlet body with an outlet pipe, and sections in the form of rings located between said bodies, while the bodies and sections are tightened along the periphery, and the sections in the form of rings are made with flanges along the inner diameter for each st upeny of the flow part, to which guide vanes and over-rotary sealing rings with axial connectors are fixed, and in the flow part of the inlet housing there is a hydraulic seal cavity separated from the flow part by the body, in which the corresponding end seal is located, and a spacer ring for supplying flow to the impeller blades of the first stages, while the flow part of the inlet body is made with a smooth transition from the inlet pipe to the inlet annulus, which has at least one radial fin installed in the direction of flow, and in the circumferential direction the axis of the fin is located at an angle of 200-250° from the axis of the inlet pipe along the direction of rotation of the pump rotor, and the joint of the spacer ring with the sealing ring of the first stage is made with a large diameter along the sealing ring and smaller, respectively, along the spacer, in addition, the pump includes an unloading system consisting of an unloading cavity and end rings mounted on the rotor shaft an impeller and an unloading drum located in the annular space of the outlet body and having a pressed unloading bushing forming a slotted seal with the drum, the unloading cavity being formed by the unloading body fixed to the outlet body from the side of the rear support of the rotor, and connected to the hydraulic seal cavity and further to the flow part of the inlet housing through at least one auxiliary pipeline, and the ends of the blades on the impeller of the first stage have a groove along the cone with a decrease in the outer diameter of the blades from the inlet to the outlet section at a constant size of the impeller hub, while being part of the rear rotor support for fixing the rotor in the axial direction includes a "floating" assembly of angular contact or thrust rolling bearings in a separate housing attached to the housing of the rear rotor support. 2. The pump according to claim 1, characterized in that the body of the hydraulic seal cavity has a smooth transition from the surface of the flow part of the inlet body, and in relation to the flow part of the bushing surface of the impeller disk of the first stage, the transition is stepped towards lowering the inlet flow diameter of the impeller disk and with a smooth entry due to the rounding of the corner at the inlet end of the disk , wherein the hydraulic seal cavity is in communication with the flow part by means of a slotted seal formed by the hydraulic seal cavity body and the hydraulic seal sleeve on the rotor. 3. Pump according to claim. 1, characterized in that the spacer ring is made separately from the inlet housing in the form of an independent part, separated from the flow part, while on the side of the flow part it has a smooth transition to the conical surface of the first stage sealing ring, and the joint of the spacer ring with the first stage sealing ring is stepped, that is, the diameter spacer rings are smaller than the diameter of this sealing ring by 0.8 ... 1.6 mm or more, with a smooth exit to the flow surface of the sealing ring, that is, the diameter of the spacer ring at the junction with the first stage sealing ring is guaranteed to be less than the diameter of the first stage sealing ring, and the specified joint is made with a gap. 4. The pump according to claim 1, characterized in that mechanical seals of double or tandem type are made for sealing the pump shaft, installed on the inlet housing and the discharge housing, respectively. 5. The pump according to claim 1, characterized in that the body of the front rotor support on the input side is mounted on the half-flange of the bracket of the input body, and the body of the rear support of the rotor on the output side is mounted on the half-flange of the discharge housing. 6. Pump according to claim. 1, characterized in that the sealing ring of the first stage, covering the impeller of the first stage, is made conical with a radial clearance at the ends of the impeller blades. 7. Pump according to claim. 1, characterized in that the bearing unit consists of an outer housing, which is hermetically fixed to the housing of the front rotor support, forming a single cavity with the cavity of the rear rotor support, and inside the cylindrical opening of the outer housing with a gap, a rolling bearing housing with a sealed cover is installed, and this gap is sealed from the ends with rubber rings , the rolling bearings are installed in the housing along the outer diameter, they are also seated and fixed on a single sleeve according to the inner diameter, which is seated with a radial clearance on the shaft spike from the output side and fixed in the axial and circumferential directions with the help of a nut and a keyway, respectively, at in this case, the mutual axial fixation of the rolling bearing housing and the outer housing is made by means of a bracket fixed on the outer housing and a central bolt resting against the bracket and screwed into the tight cover of the rolling bearing housing, the plain bearings being provided with oil rings. 8. Pump according to claim 1, characterized in that above the ends of the blades of the impellers in the case when the outer diameter of the ring of the end impeller is less than the diameter of the ends of the blades of the rotor impellers, one-piece over-rotary sealing rings are installed. 9. The pump according to claim 1, characterized in that the “floating” assembly of angular contact or thrust rolling bearings in the housing is fixed in the axial direction by a central bolt resting on a rigidly fixed bracket and screwed into the sealed cover of the rolling bearing housing, and to monitor the residual axial force on the rotor on the cylindrical section of the specified central bolt, a measuring device is installed in the form of a primary piezometric sensor. 10. Pump according to claim. 1, characterized in that housings and sections are tightened around the periphery with pins located outside the flow path.

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