RU2508474C1 - Dispersing multistage rotary pump - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: dispersing stage comprises distributor. The latter comprises top and bottom vaned disc, semi-exposed impeller including drive vaned disc. Impeller drive disc has a through circular groove. Groove width varies from two to ten percent of vane maximum OD. Circular groove is made in drive disc every vane. Distributor bottom disc diameter does not exceed 85 percent of vane OD. At least one circular cutout is made at distributor inlet in every vane.

EFFECT: better dispersion, higher reliability.

7 cl, 7 dwg

Description

The invention relates to petroleum engineering and can be used in multistage centrifugal submersible pumps for pumping formation fluids with a high gas content.

Known dispersing stage of a submersible multistage centrifugal pump (according to the patent US 5628616, F04D 29/22, publ. 13.05.1997), containing the guide apparatus and the impeller. Moreover, in a closed impeller of such a stage there is a driven disk, as well as a driving disk, with which the blades of the impeller are rigidly connected, in the spaces between which holes are made in the driving disk of the closed impeller. The disadvantage of this stage is that the impeller blades do not affect the reservoir fluid flowing under the impeller, and therefore the stage of the known design does not provide sufficiently effective crushing of gas bubbles and mud inclusions in the reservoir fluid. Large gas bubbles may form in the region between the lower impeller disk and the adjacent disk of the guide vane.

Closest to the proposed technical solution is the dispersing stage of a submersible multistage centrifugal pump (according to patent RU 2209347, IPC F04D 13/10, F04D 31/00, published on July 27, 2003), which contains a guide apparatus installed in the last open impeller, blades which are located on the lower surface of the drive disk, in which openings are made in the spaces between the places of fastening of the blades. The distance from the lower edge of each of the blades to the upper surface of the upper disk of the guide apparatus is made increasing in the direction from the inner edge of the lower edge of the blade to the outer edge of the specified edge of the blade.

The disadvantages of this device is the low dispersing properties of the stage, due to the fact that the holes in the driving wheel of the impeller, located in the spaces between the fixing points of the blades, do not allow uniform dispersion of the gas-liquid mixture along the entire length of the blade array starting from its entrance. The liquid disperses worse in the sections of the flowing part between the holes.

The technical result is to improve the dispersing properties of the stage and increase the reliability of its operation, efficiency and pressure. The efficiency and pressure of the stage increase due to the fact that the degree of dispersion of the gas-liquid mixture passing through the stage is higher, and there are no large gas bubbles in the stream.

The specified technical result is achieved due to the fact that the dispersing stage of a submersible multistage centrifugal pump, comprising a guiding apparatus, which includes a lower and upper disk with vanes, a half-open impeller, which contains a driving disk with blades, and a through ring groove is made in the driving disk of the impeller , the width of which is from two to ten percent of the maximum outer diameter of the blades, in addition, in each blade of the leading disk is made annular az, the diameter of the lower disk of the guide vane is not more than eighty-five percent of the outer diameter of the blades; at the entrance to the guide vane, at least one annular cut is made in each vane.

In addition, the depth of the annular groove in each impeller blade is at least thirty percent of the blade height.

According to an embodiment, a disk is made on the lower part of the impeller blades, the inner diameter of which is at least seventy percent of its outer diameter.

According to an embodiment, a disk with an axial support is made on the lower part of the impeller blades, the outer diameter of which exceeds the internal one by no more than 50 percent.

According to an embodiment, a disk is made on the lower part of the impeller blades, in which a through annular groove is made.

In addition, the width of the blades in the place of their attachment to the disk is at least ten percent greater than in their upper part.

In addition, the depth of the annular cutout in each blade of the guide vane is at least thirty percent of the height of the blade.

A through annular groove made in the driving wheel of the impeller, the width of which is from two to ten percent of the maximum outer diameter of the blades, allows you to evenly disperse the gas-liquid mixture along the length of the blade grate as close to its beginning.

An annular groove made in each impeller blade increases the degree of dispersion of the gas-liquid mixture, since it creates a gradient (difference) in the gas-liquid mixture flow rates in the groove region.

The reduced outer diameter of the lower disk of the guide vane and the annular cutout in each blade of the guide vane also contribute to an increase in the degree of dispersion, since in this region the flow age is maximal and obstructions in the form of vanes with an annular cut create an increased velocity gradient and thereby improve mixing.

Different depth of the annular groove in each blade of the impeller and (or) the blades of the guide apparatus allows you to change the degree of dispersion of the gas-liquid mixture, to improve the dispersing properties. An annular groove depth of at least thirty percent of the blade height will ensure optimum dispersion.

A disk made on the lower part of the impeller blades, the inner diameter of which is at least seventy percent of its outer diameter, helps prevent breakage, chipped blades and increase the reliability of the stage.

The execution of a disk with an axial support on the lower part of the blades of the impeller, the outer diameter of which exceeds the internal one by no more than 50 percent, makes it possible to increase the reliability of the stage by reducing the specific axial load on the stage and at the same time achieve high dispersing properties due to the partial absence of the drive disk.

When performing on the lower part of the blades of the impeller of the disk in which the through annular groove is made, dispersion is carried out similarly to the process described previously for the through annular groove made in the driving disk of the impeller. At the same time, the strength and reliability of the step are increased due to the fact that breakage and chipping of the blades are prevented.

The invention is illustrated by drawings, which depict:

figure 1 - sequentially installed steps made in accordance with the claimed invention;

figure 2 is a view of the driving disk of the impeller, made according to the invention;

figure 3 is a view of the annular grooves in the blades of the driving disk of the impeller in isometry;

figure 4 is a view of a through annular groove on the lower surface of the driving disk of the impeller;

figure 5 is a view of the impeller, on the lower part of the blades of which a disk is made, the inner diameter of which is at least seventy percent of its outer diameter;

Fig.6 is a view of the impeller, on the lower part of the blades of which a disk with an axial support is made, the outer diameter of which exceeds the inner one by no more than 50 percent;

Fig.7 is a view of the impeller, on the lower part of the blades of which a disk is made, in which a through annular groove is made.

The dispersing stage of a submersible multistage centrifugal pump (Fig. 1) contains a guiding apparatus 1, which includes a lower 2 and an upper disk 3 with vanes 4, and a half-open impeller 5 installed in the guiding apparatus 1, which contains a driving disk 6 with vanes 7.

In the driving disk 6 of the impeller 5, a through annular groove 8 is made, the width of which is from two to ten percent of the maximum outer diameter of the blades 7. In each blade 7 of the driving disk, an annular groove is made 9. The diameter of the lower disk 2 of the guide apparatus 1 is no more than eighty-five percent of the outer diameter of the blades 4, at the entrance to the guide apparatus 1, at least one annular cutout 10 is made in each blade 4. The depth of the annular cutout 10 in each blade 4 of the guide apparatus 1 with nent at least thirty percent of the height of the blade 4.

According to a design variant, a disk 11 can be made on the lower part of the blades 7 of the impeller 5, the inner diameter of which is at least seventy percent of its outer diameter (Fig. 5).

According to the embodiment, on the lower part of the blades 7 of the impeller 5 a disk 11 is made with an axial support 12, the outer diameter of which exceeds the inner one by no more than 50 percent (Fig. 6).

According to a design variant, a disk 11 is made on the lower part of the blades 7 of the impeller 5, in which a through annular groove 13 is made (Fig. 7).

When the pump is operating, the formation fluid flows through the grooves of the impeller 5, driven by the pump shaft, as a result, the pressure of the formation fluid is created both by centrifugal forces and by the action of the impeller 5's blades on the fluid flow. Next, the fluid enters the channels of the guide apparatus 1 of the next stage, in which the creation of additional pressure and the flow direction to the impeller of the next stage are carried out. Together with the reservoir fluid, gas bubbles and mud inclusions move along the slots of the semi-open impeller 5.

Gas inclusions brought out of the space above the driving disk 6 through the through annular groove 8 of the driving disk 6 are subjected to additional grinding by the lower edges of the blades 7 of the semi-open impeller 5, which ensures more efficient crushing of gas bubbles, at the same time efficient crushing of mud inclusions is carried out, which reduces wear of friction pairs, eliminates the possibility of jamming of the pump. The implementation of the disk 11 on the lower part of the blades 7 of the impeller 5, the inner diameter of which is at least seventy percent of its outer diameter, can prevent breakage, chips of the blades 7 of the impeller.

The execution on the lower part of the blades 7 of the impeller 5 of the disk 11 with an axial support 12, the outer diameter of which exceeds the internal by no more than 50 percent (Fig.6), increases the dispersion efficiency of the gas-liquid mixture due to the partial absence of the drive disk.

The formation in the disk 11, located on the lower part of the blades 7 of the impeller 5, a through annular groove 13, is also aimed at improving the efficiency of dispersing a gas-liquid mixture through the specified groove (Fig.7).

In addition, with an increase in the efficiency of crushing gas bubbles in mud inclusions in the reservoir fluid, the number of dispersing steps necessary for the smooth operation of the pump while maintaining the dimensions can be reduced, while the efficiency and pressure of the pump as a whole increase.

Claims (7)

1. The dispersing stage of a submersible multistage centrifugal pump, comprising a guiding apparatus, which includes a lower and upper disk with vanes, a half-open impeller, which contains a driving disk with blades, characterized in that a through ring groove is made in the driving disk of the impeller, the width of which is from two to ten percent of the maximum outer diameter of the blades, in addition, in each blade of the drive disk an annular groove is made, the diameter of the lower disk of the guide tool that is no more than eighty-five percent from the outer diameter of the blades, inlet guide vanes in each vane is made of at least one annular recess. 2. The dispersing step according to claim 1, characterized in that the depth of the annular groove in each impeller blade is at least thirty percent of the blade height. 3. The dispersing step according to claim 1, characterized in that a disk is made on the lower part of the impeller blades, the inner diameter of which is at least seventy percent of its outer diameter. 4. The dispersing step according to claim 1, characterized in that on the lower part of the impeller blades a disk with an axial support is made, the outer diameter of which exceeds the inner one by no more than 50 percent. 5. The dispersing step according to claim 1, characterized in that on the lower part of the impeller blades a disk is made in which a through annular groove is made. 6. The dispersing step according to claim 1, characterized in that the width of the blades in the place of their attachment to the disk is at least ten percent greater than in their upper part. 7. The dispersing step according to claim 1, characterized in that the depth of the annular cutout in each blade of the guide vane is at least thirty percent of the height of the blade.

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