CN112555559B - Non-uniform incoming flow suppression device at pump inlet - Google Patents

Abstract

The invention provides a device for suppressing non-uniform inflow of a pump inlet, comprising a casing and a rotary body. The casing is provided with an ellipsoidal cavity, the two ends of the casing are open, the rotary body is arranged inside the casing, and the rotary body is connected to the casing. The inner walls are fixedly connected by connecting columns; the revolving body is formed by rotating the revolving section by 360° around the center line of the shell, and the revolving section is closed by an outer arc, an inner arc, a right-angled edge and a rounded edge. By arranging the non-uniform inflow suppressing device of the present invention at the front end of the pump inlet, the high velocity center of the water flow originally shifted to one side can be effectively returned to the center of the pipeline, and the corrected water flow gradient distribution is center-symmetrical, thereby making the pump impeller and the The force of the pump shaft is balanced, which ensures the stability of the pump operation and improves the operation efficiency of the pump.

Description

A device for suppressing non-uniform inflow of pump inlet

technical field

The invention belongs to the field of fluid systems, in particular to a device for suppressing non-uniform inflow of a pump inlet.

Background technique

Usually, in the process of water pipe delivery, the water flow velocity at the center of the water pipe is the highest, and gradually decreases as it approaches the edge of the water pipe. However, in some special cases, there is a phenomenon that the center of the high flow velocity in the water pipe is shifted to one side. For example, in the drain pipe of the lower chamber of a nuclear power plant, due to the special structure of the lower chamber, the center of the high flow velocity of the water flow in the drain pipe is offset. Move to the side of the hose.

The above phenomenon of high flow velocity center offset of water flow in the water pipe will cause asymmetric distribution of the water flow velocity gradient in the pipe, which will lead to uneven force on the impeller and pump shaft of the pump when the pump connected to the back end of the water pipe is working, which will eventually reduce the pump's performance. efficiency, as well as increased vibration and noise.

SUMMARY OF THE INVENTION

Aiming at the deficiencies in the prior art, the present invention provides a device for suppressing the non-uniform inflow of the pump inlet, which is used to solve the problem of high-velocity center offset of the water flow in the water pipe.

The present invention achieves the above technical purpose through the following technical means.

A device for suppressing non-uniform inflow of a pump inlet, comprising a casing and a rotating body, an ellipsoidal cavity is arranged inside the casing, the two ends of the casing are open, the rotating body is arranged inside the casing, and the rotating body and the inner wall of the casing are arranged between the rotating body and the inner wall of the casing. Fixed by connecting column;

The revolving body is formed by rotating the revolving section around the center line of the shell by 360°, and the revolving section is closed by an outer arc, an inner arc, a right-angled edge and a rounded edge; the outer arc is composed of point P1, point Pm and point P1. It consists of Pn, the point Pm is the midpoint of the outer arc, the inner arc is composed of points Q1, Qm and Qn, the point Qm is the midpoint of the inner arc, the right angle side is composed of two intersecting sides, and the endpoint of one side is Qn , the endpoint of the other side is Pn, and the rounded edge is composed of the curve from point P1 to point Q1;

Both the outer circular arc and the inner circular arc protrude toward the outside of the rotating body, and the right-angled edge and the rounded edge both protrude toward the outside of the rotating section.

Further, the distances of the points P1, Pm and Pn from the center line (13) are respectively h1, hm and hn, and satisfy 0.29D<h1<0.39D, 0.67D<hm<0.77D, and 0.41D<hn< 0.51D, where D is the diameter of the water pipe.

Further, the two sides of the right-angled side are perpendicular to each other, wherein the vertical side is perpendicular to the center line, and the end point of the vertical side is the point Pn.

Further, the lengths of both sides of the right-angled side are L, and satisfy 0.23D<L<0.39D.

Further, the distances of the points Q1 and Qm from the center line are t1 and tm, respectively, and satisfy 0.23D<t1<0.33D and 0.29D<tm<0.39D.

Further, there are four connecting columns, which are evenly distributed on the outer side of the rotating body along the rotational circumferential direction.

Further, the connecting column has a cylindrical structure, and the diameter R satisfies 0.09D<R<0.13D.

Further, the rounded edges are respectively smoothly connected with the outer arc and the inner arc.

Further, the outside of the casing is an ellipsoid structure.

Further, the size of the openings at both ends of the casing matches the inner diameter of the water pipe.

The beneficial effects of the present invention are:

(1) By arranging the non-uniform inflow suppressing device of the present invention at the front end of the pump inlet, the high velocity center of the water flow originally shifted to one side can be effectively returned to the center of the pipeline, and the corrected water flow gradient distribution is center-symmetric; The above correction makes the force of the pump impeller and the pump shaft balance, which ensures the stability of the pump operation and improves the pump operation efficiency.

(2) The non-uniform inflow suppression device at the pump inlet of the present invention has a simple and compact structure, and is directly connected to the front end of the pump by a water pipe, and does not occupy additional space.

(3) The present invention provides the size requirements of each structure in the device, which is verified by simulation software to ensure that the correction effect is excellent and at the same time, the loss of the overall water flow velocity is small.

Description of drawings

Fig. 1 is the structure diagram of the non-uniform inflow suppression device at the pump inlet of the present invention;

Fig. 2 is a rotary cross-sectional view of the present invention;

Fig. 3 is the use state diagram of the present invention;

Figure 4(a) is the flow velocity distribution diagram of the deviation of the high flow velocity center of the water flow in the pipeline;

Figure 4(b) is a flow velocity distribution diagram of the water flow in the pipeline after being suppressed by the device of the present invention;

Reference numerals: 1. Shell, 11. Water inlet, 12. Water outlet, 13. Center line, 2. Connecting column, 3. Rotary body, 31. Rotary section, 311. Outer arc, 312. Inner arc , 313. Right-angled edge, 314. Rounded edge, 41. Water pump, 42. Lower chamber, 43. Water pipe.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the present invention and should not be construed as limiting the present invention.

The non-uniform inflow suppression device at the pump inlet as shown in Fig. 1 includes a casing 1 and a rotary body 3; the casing 1 is a hollow ellipsoid structure with open front and rear ends, one end is the water inlet 11, and the other end is the water outlet 12. The cross-sections of the water inlet 11 and the water outlet 12 are both circular, and the size matches the inner diameter D of the water pipe 43 .

The revolving body 3 is arranged inside the housing 1. The revolving body 3 is composed of a revolving section 31 rotated 360° around the centerline 13 of the housing 1. The outer side of the revolving body 3 is evenly connected with four cylindrical connecting columns along the rotational circumferential direction. 2. The diameter R of the connecting column 2 satisfies: 0.09D<R<0.13D; the rotating body 3 is fixedly connected to the inner wall of the casing 1 through the connecting column 2 .

The revolving section 31 shown in FIG. 2 is closed by an outer arc 311, an inner arc 312, a right-angled side 313 and a rounded side 314, and the right-angled side 313 is located on the side close to the water outlet 12, and the rounded side 314 is located at the side of the water outlet 12. Close to the side of the water inlet 11; the outer arc 311 is composed of a point P1, a point Pm and a point Pn, wherein the point Pm is the midpoint of the arc; the inner arc 312 is composed of a point Q1, a point Qm and a point Qn, The point Qm is the midpoint of the circular arc; the right-angled side 313 is formed by the intersection of the horizontal side and the vertical side, wherein the horizontal side is parallel to the center line 13, the end point of the horizontal side is the point Qn, the vertical side is perpendicular to the center line 13, and the vertical side is The end point is the point Pn; the rounded edge 314 is a curve from the point P1 to the point Q1 , which functions to smoothly connect the outer arc 311 and the inner arc 312 .

The requirements for each dimension in the revolving section 31 are as follows:

The distances of the points P1, Pm and Pn on the outer arc 311 from the center line 13 are respectively h1, hm and hn, respectively satisfying: 0.29D<h1<0.39D, 0.67D<hm<0.77D, 0.41D<hn< 0.51D;

The lengths of the horizontal side and the vertical side of the right-angle side 313 are both L, which satisfies: 0.23D<L<0.39D;

The distances of the points Q1 and Qm on the inner arc 312 from the center line 13 are respectively t1 and tm, which satisfy: 0.23D<t1<0.33D and 0.29D<tm<0.39D.

The use example and effect of the present invention are as follows:

As shown in FIG. 3 , the device for suppressing the non-uniform inflow of the pump inlet of the present invention is arranged between the water pump 41 and the lower chamber 42 of the nuclear power plant, wherein the water inlet 11 of the device of the present invention is connected to the water outlet of the lower chamber 42 through a water pipe 43, The water outlet 12 is connected to the inlet of the water pump 41 through a water pipe 43 .

ANSYS CFX simulation software is used to simulate the situation of the above-mentioned water pump 41 pumping water from the lower chamber 42. The simulation results are shown in Fig. 4(a) and Fig. 4(b), in which Fig. 4(a) shows that the non-uniform flow is not set. Flow suppression device, when the water pump 41 directly pumps water from the lower chamber 42 through the water pipe 43, the flow velocity distribution diagram at the pump inlet pipe, Figure 4(b) is the flow velocity distribution at the pump inlet pipe after the non-uniform inflow suppression device is installed In the two figures, the color depth is used to represent the low and high flow velocity; according to the comparison between Figure 4(a) and Figure 4(b), it can be concluded that:

After the device of the present invention is adopted, the deviation of the high velocity center of the water flow in the pipe of Fig. 4(a) to one side is suppressed, so that the high velocity center is corrected back to the center of the pipe as shown in Fig. 4(b), and the velocity gradient distribution is as shown in Fig. 4(b). The center-symmetrical decreases toward the edge; compared with Fig. 4(a), the overall change in color depth is not large in Fig. 4(b), which means that the device of the present invention does not cause great loss to the overall flow velocity of the water flow.

The described embodiment is the preferred embodiment of the present invention, but the present invention is not limited to the above-mentioned embodiment, without departing from the essence of the present invention, any obvious improvement, replacement or All modifications belong to the protection scope of the present invention.

Claims (8)

1. A pump inlet non-uniform incoming flow suppression device, characterized by: the device comprises a shell (1) and a revolving body (3), wherein an ellipsoidal cavity is arranged in the shell (1), two ends of the shell (1) are open, the revolving body (3) is arranged in the shell (1), and the revolving body (3) is fixedly connected with the inner wall of the shell (1) through a connecting column (2);

the revolving body (3) is formed by revolving a section (31) around the central line (13) of the shell (1) for 360 degrees, and the revolving section (31) is formed by closing an outer arc (311), an inner arc (312), a right-angle side (313) and a round-angle side (314); the outer arc (311) consists of a point P1, a point Pm and a point Pn, the point Pm is the midpoint of the outer arc (311), the inner arc (312) consists of a point Q1, a point Qm and a point Qn, the point Qm is the midpoint of the inner arc (312), the right-angle side (313) consists of two intersected sides, the end point of one side is Qn, the end point of the other side is Pn, and the round-angle side (314) consists of a curve from the point P1 to the point Q1; the distances from the points P1, Pm and Pn to the central line (13) are h1, hm and hn, and satisfy 0.29D < h1 < 0.39D, 0.67D < hm < 0.77D, 0.41D < hn < 0.51D, wherein D is the diameter of the water pipe (43); the distances between the points Q1 and Qm from the central line (13) are t1 and tm respectively, and 0.23D < t1 < 0.33D and 0.29D < tm < 0.39D are satisfied;

the outer arc (311) and the inner arc (312) are convex towards the outer side of the revolving body (3), and the right-angle side (313) and the round-angle side (314) are convex towards the outer side of the revolving section (31).

2. The pump inlet non-uniform inflow suppression device of claim 1, wherein: two sides of the right-angle side (313) are vertical to each other, wherein the vertical side is vertical to the central line (13), and the end point of the vertical side is a point Pn.

3. The pump inlet non-uniform inflow suppression device of claim 2, wherein: the lengths of the two sides of the right-angle side (313) are L, and the L is more than 0.23D and less than 0.39D.

4. The pump inlet non-uniform inflow suppression device of claim 1, wherein: four connecting columns (2) are uniformly distributed on the outer side of the revolving body (3) along the rotating circumferential direction.

5. The pump inlet non-uniform inflow suppression device of claim 4, wherein: the connecting column (2) is of a cylindrical structure, and the diameter R is more than 0.09D and less than 0.13D.

6. The pump inlet non-uniform inflow suppression device of claim 1, wherein: the fillet edge (314) is respectively and smoothly connected with the outer arc (311) and the inner arc (312).

7. The pump inlet non-uniform inflow suppression device of claim 1, wherein: the outer part of the shell (1) is of an ellipsoidal structure.

8. The pump inlet non-uniform inflow suppression device of claim 1, wherein: the opening sizes of the two ends of the shell (1) are matched with the inner diameter of the water pipe (43).

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