Smooth automatic device and method for reservoir sediment flushing

Abstract

This invention reveals a smooth automatic device and method for efficiently flushing sediment from a reservoir. It includes a sediment flushing funnel located at the reservoir dam's bottom, connected to a sediment flushing pipe. This pipe extends from the funnel's bottom through a smooth connecting pipe, horizontally through the dam, and then to the downstream river channel. Inside the funnel, a trigger-control mechanism is installed, linked to a sediment flushing ball valve within the sediment flushing pipe. The invention operates by automatically opening the ball valve when sediment accumulation in the funnel hits a preset threshold. The sediment is then released into the downstream river channel via the smooth connecting pipe and flushing pipe, driven by gravity. This system offers an effective solution for automatic reservoir sediment flushing, boasting high efficiency, energy conservation, and water resource savings.

Claims

1. A smooth automatic device for reservoir sediment flushing, comprising a sediment flushing funnel set at bottom of a reservoir dam and a sediment flushing pipe, one end of the sediment flushing pipe is smoothly connected to bottom of the sediment flushing funnel through a smooth connecting pipe, and an other end of the sediment flushing pipe is horizontally connected to a downstream river channel after passing through the reservoir dam; a trigger-control mechanism is installed inside the sediment flushing funnel, and a sediment flushing ball valve connected with the trigger-control mechanism is installed inside the sediment flushing pipe; wherein the trigger-control mechanism comprises: a vertical pipe set on an inner wall of the sediment flushing funnel, and an upper piston assembly and a lower piston assembly set inside the vertical pipe, capable of vertically sliding; the lower piston assembly is connected to top of a connecting rod, bottom of the connecting rod passes through the vertical pipe and is connected eccentrically with a first transmission gear, the first transmission gear and a second transmission gear are meshed, and the second transmission gear is linked to the sediment flushing ball valve; bottom of the vertical pipe is connected with bottom of a clean-water pipe, and top of the clean-water pipe is located in a clean-water area of a reservoir; and a height of top of the vertical pipe is lower than a height of top of the sediment flushing funnel; wherein the upper piston assembly comprises: an upper piston body and an upper spring arranged between the upper piston body and the inner wall of the sediment flushing funnel; a sealing ring is arranged between the upper piston body and an inner wall of the vertical pipe, and the sealing ring is used to keep sediment above the upper piston body separate from clean water below the upper piston body, so that a pressure difference of the upper piston body is equal to an underwater weight of the sediment; the lower piston assembly comprises: a lower piston body set below the upper piston body and a lower spring located between the lower piston body and the inner wall of the sediment flushing funnel; and the upper spring is inserted into the lower spring after passing through a center of the lower piston body.

2. The smooth automatic device for reservoir sediment flushing according to claim 1, wherein a transmission ratio I.sub.R of the first transmission gear and the second transmission gear is determined by following formula: $I_R=\frac{2}{}\mathrm{arc}\cos \left[\frac{h^2-2Lh}{2r\left(L+r-h\right)}+1\right]$ wherein, h is a set height of the lower piston body, L is a length of the connecting rod, r is a distance from the connecting rod to a center of the first transmission gear, z.sub.1 is a number of teeth of the first transmission gear, and z.sub.2 is a number of teeth of the second transmission gear; when the lower piston body slides downward in the vertical pipe for a distance h to the bottom of the vertical pipe, the first transmission gear is driven to rotate an angle , and a gear transmission ratio is $I_R=\frac{2}{},$ so that a rotation angle of the sediment flushing ball valve is equal to /2 or 90; when the lower piston body slides downward in the vertical pipe for the distance h to the bottom of the vertical pipe, the first transmission gear is driven to rotate an angle .sub.1, wherein a relation among .sub.1, a sliding height h that the lower piston body slides, the length L of the connecting rod, and the distance r from the connecting rod to the center of the first transmission gear is expressed as $\cos {}_1=\frac{r^2+{\left(L+r-h\right)}^2-L^2}{2r\left(L+r-h\right)}=\frac{h^2-2Lh}{2r\left(L+r-h\right)}+1$ from which a new formula is derived: ${}_1=\mathrm{arc}\cos \left[\frac{h^2-2Lh}{2r\left(L+r-h\right)}+1\right]$ a relation between a rotation angle .sub.1 of the first transmission gear and a rotation angle .sub.2 of the second transmission gear is expressed as: ${}_2=\frac{z_2}{z_1}{}_1=\frac{z_2}{z_1}\mathrm{arc}\cos \left[\frac{h^2-2Lh}{2r\left(L+r-h\right)}+1\right]$ wherein, .sub.2 is the rotation angle of the sediment flushing ball valve and is equal to 90.

3. The smooth automatic device for reservoir sediment flushing according to claim 2, wherein an elastic force F.sub.S(t) of the upper spring is equal to a submerged weight of sediment in the vertical pipe, which is expressed as: $F_S\left(t\right)=\left({}_S-\right)R^{2}h\left(t\right)$ wherein, R is an internal radius of the vertical pipe or a radius of the upper piston body; h(t) is a deposition above surface of the upper piston body and is a function of time t; a maximum elastic force that the upper spring can withstand is expressed as: $F_{S\max }=k\left({}_S-\right)R^2{h}_{\max }$ wherein, k is a parameter of a normal distributional funnel, set to be 1.11.2, h.sub.max is approximately equal to H, .sub.S is a density of accumulated sediment, is a density of water, and H is a height from a mud surface to the bottom of the sediment flushing funnel.

4. The smooth automatic device for reservoir sediment flushing according to claim 3, wherein linkage trigger heads that are capable of horizontally sliding are installed symmetrically at the top and the bottom of the vertical pipe, and the linkage trigger heads on a same side of the top and bottom of the vertical pipe are connected by a linkage rod; a limit allowance suitable for the upper piston body is provided between two linkage trigger heads installed at the top of the vertical pipe, and a limit allowance suitable for the lower piston body is provided between two linkage trigger heads installed at the bottom of the vertical pipe; an extrusion spring is set between the vertical pipe and each of the linkage trigger heads.

5. The smooth automatic device for reservoir sediment flushing according to claim 4, wherein the sediment flushing funnel is a normal distributional funnel, and the normal distributional funnel is formed by rotating a concave normal-distribution curve around an axis of symmetry; the sediment flushing pipe is an inverse hyperbolic tangent pipe, and a central curve of the inverse hyperbolic tangent pipe is an inverse hyperbolic tangent curve; both the normal distributional funnel and the inverse hyperbolic tangent pipe have arbitrary order of derivatives and have arbitrary degree of smoothness.

6. The smooth automatic device for reservoir sediment flushing according to claim 5, wherein top of the smooth connecting pipe is tangent to bottom of the normal distributional funnel, and bottom of the smooth connecting pipe is tangent to top of the inverse hyperbolic tangent pipe; the smooth connecting pipe adopts the following design: in a longitudinal section y=0 of the normal distributional funnel, a single variable normal distribution form corresponding to the normal distributional funnel is denoted as z=h(x), and a function corresponding to a curve at an entrance of the inverse hyperbolic tangent pipe is denoted as z=g(x), wherein, a surface of the normal distributional funnel and the entrance of the inverse hyperbolic tangent pipe are rotationally symmetrical with respect to an ordinate z; a slope of an outlet (x.sub.0, 0, z.sub.0) at the normal distributional funnel is denoted as h-(x.sub.0), a slope at the entrance (x.sub.1, 0, z.sub.1) of the inverse hyperbolic tangent channel is denoted as g-(x.sub.1), wherein |x.sub.0|>|x.sub.1|, let $C\left(x\right)=z_0+h^{}\left(x_0\right)\left(x-x_0\right)+{{}_2\left(x-x_0\right)}^2+{{}_3\left(x-x_0\right)}^3$ wherein, .sub.2 and .sub.3 are polynomial coefficients depending on the slopes h-(x.sub.0) and g-(x.sub.1), respectively: ${}_2=\frac{3\left(z_1-z_0\right)-\left(x_1-x_0\right)\left(2h^{}\left(x_0\right)+g^{}\left(x_1\right)\right)}{{\left(x_1-x_0\right)}^2}$ ${}_3=\frac{\left(h^{}\left(x_0\right)+g^{}\left(x_1\right)\right)\left(x_1-x_0\right)+2\left(z_0-z_1\right)}{{\left(x_1-x_0\right)}^3}$ wherein a pipe body of the smooth connecting pipe is a rotationally symmetric surface z=C(x, y) corresponding to a curve C(x).

7. A smooth automatic method for reservoir sediment flushing, which is based on the smooth automatic method for reservoir sediment flushing according to claim 5, comprising: step s1: reservoir sediment is dropped into the normal distributional funnel before reaching the reservoir dam, wherein the reservoir sediment enters the vertical pipe and acts on an upper surface of the upper piston body, the clean-water pipe transmits a pressure of a clean-water column between a surface of water and the upper piston body, to a lower surface of the upper piston body; step s2: with an increase in sediment mass, a pressure difference between top and bottom of the upper piston body in the vertical pipe becomes larger, the upper piston body slides downward along the vertical pipe under an action of reservoir sediment pressure until the upper piston body reaches the lower piston body; the reservoir sediment continues to be deposited, and the upper piston body and the lower piston body slide downward together; when the sediment mass in the normal distributional funnel increases to a threshold M.sub.1-(H), a force experienced by the upper piston body reaches a set threshold M.sub.p=M.sub.1(H), and the lower piston body reaches the bottom of the vertical pipe, wherein, is set according to a ratio of a volume of a deposition volume R.sup.2h.sub.max above the upper piston body to a volume of the normal distributional funnel with a same top elevation, M.sub.1-(H) is a force threshold of the upper piston body; step s3: downward movement of the lower piston body drives the connecting rod to move downward to drive the first transmission gear to rotate, and further to drives the second transmission gear to rotate, so as to drive the sediment flushing ball valve into rotation and to be gradually opened, sediment accumulated in the normal distributional funnel is discharged from the reservoir to the downstream river channel through the smooth connecting pipe; at this moment, the lower piston body is stuck between the two linkage trigger heads installed at the bottom of the vertical pipe, which limits an action of the lower piston body, and the sediment flushing ball valve is fully opened to complete sediment flushing continuously; step s4: in a process of sediment discharge in the normal distributional funnel, the pressure difference between the top and bottom of the upper piston body decreases, and the upper piston body gradually resets under an action of the upper spring, when the upper piston body reaches the top of the vertical pipe, the two linkage trigger heads installed at the top of the vertical pipe are triggered; then the two linkage trigger heads installed at the bottom of the vertical pipe are opened, so that the lower piston body is free from limits and can be reset under an action of the lower spring to drive the connecting rod to move upward along the vertical pipe, and to drive the sediment flushing ball valve to be closed through the first transmission gear and the second transmission gear; and step s5: step s1 to step s4 are cycled.

8. The smooth automatic method for reservoir sediment flushing according to claim 7, wherein in step s1, a buoyancy of the upper piston body is equal to $F_S\left(t\right)=R^{2}h\left(t\right),$ and the threshold M.sub.1(H) in step s2 is calculated by following formula: $M_1\left(H\right)=2\left({}_s-\right){}^{2}H\left[1-\left(1-\frac{k}{\sqrt{2}H}\right)\ln \left(1-\frac{\sqrt{2}H}{k}\right)\right]$ wherein, is a variance parameter of the normal distributional funnel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an assembly drawing of the present invention;

(2) FIG. 2 is a front view of the sediment flushing funnel-smooth connecting pipe-desilting pipe of the present invention;

(3) FIG. 3 is a top view of the sediment flushing funnel-smooth connecting pipe-desilting pipe of the present invention;

(4) FIG. 4 is a schematic diagram of the trigger-control mechanism of the present invention;

(5) FIG. 5 is a front view of the trigger-control mechanism of the present invention;

(6) FIG. 6 is a side view of the trigger-control mechanism of the present invention;

(7) FIG. 7 is a front view of the sediment flushing ball valve of the present invention.

(8) Wherein, 1. sediment flushing funnel; 2. smooth connecting pipe; 3. sediment flushing pipe; 4. trigger-control mechanism; 41. vertical pipe; 42. upper piston assemblies; 421. upper piston body; 422. upper spring; 43. lower piston assemblies; 431. lower piston body; 432. lower spring; 44. connecting rod; 45. first transmission gear; 46. the second transmission gear; 47. linkage trigger head; 5. sediment flushing ball valve; 6. clean-water pipe; 7. dam.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(9) The following will further describe the invention in combination with the attached diagram. It should be noted that this embodiment is based on this technical scheme, and gives a detailed implementation method and specific operation process, but the protection scope of the invention is not limited to this embodiment.

(10) FIG. 1 is an assembly drawing of the present invention; FIG. 2 is a front view of the sediment flushing funnel-smooth connecting pipe-sediment flushing pipe of the present invention; FIG. 3 is a top view of the sediment flushing funnel-smooth connecting pipe-sediment flushing pipe of the present invention; FIG. 4 is a schematic diagram of the trigger-control mechanism of the present invention; FIG. 5 is a front view of the trigger-control mechanism of the present invention; FIG. 6 is a side view of the trigger-control mechanism of the present invention; FIG. 7 is a front view of the sediment flushing ball valve of the present invention, as shown in FIG. 1-FIG. 7, a smooth automatic reservoir sediment flushing device, which includes a sediment flushing funnel 1 set at the bottom of the reservoir dam 7 and a sediment flushing pipe 3 connected to the bottom of the sand collection funnel 1 by a smooth connecting pipe 2 at one end, the other end of the sediment flushing pipe 3 passes through the dam 7 horizontally and connects with the downstream river channel; a trigger-control mechanism 4 is set inside the sediment flushing funnel 1, and a sediment flushing ball valve 5 connected with the trigger-control mechanism 4 is arranged in the sediment flushing pipe 3, in this implementation, the sediment flushing ball valve 5 is set at the entrance of the sediment flushing pipe 3;

(11) Preferably, the trigger-control mechanism 4 includes a vertical pipe 41 set on the inner wall of the sediment flushing funnel 1 and an upper piston assembly 42 and a lower piston assembly 43 set inside the vertical pipe 41, capable of vertically slidingn, the lower piston assembly 43 is connected to the top of the connecting rod 44, the bottom end of the connecting rod 44 passes through the vertical pipe 41 and is connected eccentrically with a first transmission gear 45, the first transmission gear 45 and a second transmission gear 46 are meshed, and the second transmission gear 46 is linked to the sediment flushing ball valve 5; the bottom end of the vertical pipe 41 is connected with the bottom end of the clean-water pipe 6, and the top end of the clean-water pipe 6 is located in the clean water area of the reservoir; the height of the vertical pipe 41's top is lower than the height of the sediment flushing funnel's top, which ensures that the pressure on the upper piston body 421 is equal to the mud column of the same height in the normal distributional funnel.

(12) Preferably, the upper piston assemblies 42 include the upper piston body 421 and the upper spring 422 located between the upper piston body 421 and the inner wall of the sediment flushing funnel 1; a sealing ring is arranged between the upper piston body 421 and the inner wall of the vertical pipe 41, which is used to keep the upper sediment of the upper piston body 421 separate from the clean water below, so that the pressure difference of the upper piston body 421 is equal to the underwater gravity of the sediment, and the force of the upper spring 422 and the lower spring 432 is reduced; the lower piston assemblies 43 include the lower piston body 431 set below the upper piston body 421 and the lower spring 432 located between the lower piston body 431 and the inner wall of the sediment flushing funnel 1; the upper spring 422 is inserted into the lower spring 432 after passing through the center of the lower piston body 431.

(13) 3. the smooth automatic device for reservoir sediment flushing according to claim 2, wherein the transmission ratio I.sub.R of the first transmission gear and the second transmission gear is determined by the following formula:

(14) $I_R=\frac{2}{}\mathrm{arc}\cos \left[\frac{h^2-2Lh}{2r\left(L+r-h\right)}+1\right]$
wherein, h is the set height of the lower piston body, L is the length of the connecting rod, r is the distance from the connecting rod to the center of the first transmission gear, z.sub.1 is the number of teeth of the first transmission gear, and z.sub.2 is the number of teeth of the second transmission gear; at the time that the piston body in the vertical pipe sliding down a distance h to the bottom and driving the first transmission gear rotation to rotate an angle , the gear transmission ratio is

(15) $I_R=\frac{2}{},$
so that the rotation angle of the sediment flushing ball valve equal to /2 or 90; when the lower piston body 431 slides downward in the vertical pipe 41 to the bottom, it drives the first transmission gear 45 to rotate an angle .sub.1, where the relation between .sub.1, the sliding height h of the lower piston body 431, the length L of the connecting rod 44, and the distance r between the end point of the connecting rod 44 and the center of the first transmission gear 45 is described as:

(16) $\cos {}_1=\frac{r^2+{\left(L+r-h\right)}^2-L^2}{2r\left(L+r-h\right)}=\frac{h^2-2\mathrm{Lh}}{2r\left(L+r-h\right)}+1$
from which a new formula is deduced:

(17) ${}_1=\arccos \left[\frac{h^2-2Lh}{2r\left(L+r-h\right)}+1\right]$ the relation between the first gear rotation angle .sub.1 and the second gear rotation angle .sub.2 is:

(18) ${}_2=\frac{z_2}{z_1}{}_1=\frac{z_2}{z_1}\mathrm{arc}\cos \left[\frac{h^2-2Lh}{2r\left(L+r-h\right)}+1\right]$ wherein, .sub.2 is the rotation angle of the sediment flushing ball valve 90.

(19) Preferably, the elastic force F.sub.S(t) of the upper spring 42 is equal to the underwater gravity of the sediment in the vertical pipe, that is:

(20) $F_S\left(t\right)=\left({}_S-\right)R^{2}h\left(t\right)$ wherein, R is the internal radius of the vertical pipe 41 or the radius of the upper piston body 421; h(t) is the deposition above the surface of the upper piston body 421, and it is a function of time t; the maximum elastic force that the upper spring 422 can withstand is:

(21) $F_{S\max }=k\left({}_S-\right)R^2{h}_{\max }$ wherein, k is a parameter of the normal distributional funnel, set to be 1.11.2, h.sub.max is approximately equal to H, .sub.S is the density of accumulated sediment. is the density of water, and H is the height of the mud surface from the bottom of the funnel.

(22) Preferably, linkage trigger heads that are capable of horizontally sliding are installed symmetrically at the upper end and the lower end of the vertical pipe 41, and the linkage trigger heads on the same side of the upper and lower ends are connected by a linkage rod;

(23) there is a limit allowance suitable for the upper piston body 421 between the two linkage trigger heads 47 at the top, and there is a limit allowance suitable for the lower piston body 431 between the two linkage trigger heads 47 at the bottom; an extrusion spring is set between the linkage trigger head 47 and the vertical pipe 41.

(24) Preferably, the sediment flushing funnel 1 is a normal distributional funnel, and the normal distributional funnel is formed by rotating a concave normal-distribution curve around the axis of symmetry; the sediment flushing pipe 3 is an inverse hyperbolic tangent pipe, and the central curve of the inverse hyperbolic tangent pipe is an inverse hyperbolic tangent curve.

(25) Both the normal distributional funnel and the inverse tangent pipe have arbitrary order of derivatives and have arbitrary degree of smoothness.

(26) Preferably, the top of the smooth connecting pipe 2 is tangent to the bottom of the normal distributional funnel, and the bottom of the smooth connecting pipe 2 is tangent to the top of the inverse hyperbolic tangent pipe; the smooth connection pipe 2 adopts the following design: in the normal distributional funnel longitudinal section y=0, denote the single variable normal distribution corresponding to the normal distributional funnel as z=h(x), and the function form corresponding to the curve at the entrance of the inverse hyperbolic tangent pipe as z=g(x), wherein, the normal distributional funnel surface and the entrance of the inverse hyperbolic tangent pipe are rotationally symmetrical with respect to the ordinate z; the slope at the normal distributional funnel outlet (x.sub.0, 0, z.sub.0) is denoted as h (x.sub.0), the slope at the entrance of the inverse hyperbolic tangent channel (x.sub.1, 0, z.sub.1) is g (x.sub.1), wherein |x.sub.0|>|x.sub.1|, let

(27) $C\left(x\right)=z_0+h^{}\left(x_0\right)\left(x-x_0\right)+{{}_2\left(x-x_0\right)}^2+{{}_3\left(x-x_0\right)}^3$
wherein, .sub.2 and .sub.3 are the polynomial coefficients depending on the slopes h (x.sub.0) and g (x.sub.1), respectively:

(28) 0${}_2=\frac{3\left(z_1-z_0\right)-\left(x_1-x_0\right)\left(2h^{}\left(x_0\right)+g^{}\left(x_1\right)\right)}{{\left(x_1-x_0\right)}^2}$${}_3=\frac{\left(h^{}\left(x_0\right)+g^{}\left(x_1\right)\right)\left(x_1-x_0\right)+2\left(z_0-z_1\right)}{{\left(x_1-x_0\right)}^3}$

(29) The pipe body of the smooth connecting pipe is the rotationally symmetric surface z=C(x, y) obtained by rotating the curve C(x). in this embodiment, the selection of design parameters such as z.sub.0, z.sub.1, h(x.sub.0) should meet certain restrictive conditions, for example, under the assumption of .sub.30, it should satisfy:

(30) ${}_2^2<3h^{}\left(x_0\right){}_3$
or

(31) $\{\begin{array}{c}{}_2^2.Math.3h^{}\left(x_0\right){}_3.Math.\\ .Math.h^{}\left(x_0\right).Math.{}_3\end{array}$

(32) A smooth automatic method for reservoir sediment flushing includes the following steps: S1. the reservoir sediment drops into a normal funnel before reaching the front of the dam 7 and meanwhile, the sediment enters the vertical pipe 41 and acts on the upper surface of the upper piston body 421, the clean-water pipe 6 transmits the pressure of the clean-water column between the water surface and the upper piston body 421 to the lower surface of the upper piston body 421; S2. with the increase of sediment mass, the pressure difference between the upper and lower sides of the upper piston body 421 in the vertical pipe 41 becomes larger, the upper piston body 421 slides downward along the vertical pipe 41 under the action of sediment pressure until it reaches the lower piston body 431, the sediment continues to deposit, and the upper piston body 421 and the lower piston body 431 slide downward together; when the sediment mass in the normal distributional funnel increases to the threshold M.sub.1 (H), the force of the upper piston body 421 reaches the set threshold Mp=M.sub.1 (H), and the lower piston body reaches the bottom of the vertical pipe, wherein, is set according to the ratio of the volume of the upper deposition volume R.sup.2 h.sub.max of the upper piston body to the volume of the normal distributional funnel with the same top elevation, M.sub.1 (H) is the force threshold of the upper piston body 421; S3. the downward movement of the lower piston body 431 drives the connecting rod 44 to move downward, drives the first transmission gear 45 to rotate, and further drives the second transmission gear 46 to rotate, so as to drive the sediment flushing ball valve 5 into rotation and to be gradually opened, the sediment accumulated in the normal distributional funnel is discharged from the reservoir to the downstream river channel through the smooth connecting pipe 2; at this time, the lower piston body 431 is stuck between the two linkage trigger heads 47 at the lower end, which limits the action of the lower piston body 431, and the draining sand ball valve 5 is fully opened to complete sediment flushing continuously; S4. in the process of sediment discharge in the normal distributional funnel, the pressure difference between the upper and lower sides of the upper piston body 421 decreases, and the upper piston body 421 gradually resets under the action of the upper spring 422, until it reaches the top of the vertical pipe 41, where the two linkage trigger heads 47 at the top are triggered; the two linkage trigger heads 47 at the bottom are opened, so that the lower piston body 431 is free from limits, and it can be reset under the action of the lower spring 432, driving the connecting rod 44 to move upward along the vertical pipe 41, and driving the sediment flushing ball valve 5 to be closed through the first transmission gear 45 and the second transmission gear 46; S5. Cycle step S1-step S4.

(33) Preferably, in step S1, the buoyancy of the upper piston body 421 is equal to:

(34) $F_S\left(t\right)=R^{2}h\left(t\right),$ the threshold M.sub.1(H) in step S2 is calculated by the following formula:

(35) $M_1\left(H\right)=2\left({}_s-\right){}^{2}H\left[1-\left(1-\frac{k}{\sqrt{2}H}\right)\ln \left(1-\frac{\sqrt{2}H}{k}\right)\right]$ where is the variance parameter of the normal distributional funnel.

(36) Therefore, the present invention adopts the above-mentioned smooth automatic device and method for reservoir sediment flushing, which can open the sediment flushing ball valve when the mass of sediment in the sediment flushing funnel, reaches the set threshold, and the sediment is discharged into the downstream river channel through the smooth connecting pipe and sediment flushing pipe under the action of gravitational force, so as to realize the automatic reservoir sediment flushing, and has the advantages of high efficiency, being energy saving and water resources saving.