CN109630478B - Streamline annular jet pump - Google Patents

Abstract

The invention provides a streamlined annular jet pump. The streamlined annular jet pump is designed by designing the conical suction chamber, cylindrical throat and conical diffusion pipe of the existing annular jet pump into a streamlined suction chamber and a streamlined mixing tube; the original broken line connection is replaced by a streamlined connection. This solves the problem of serious local head loss caused by the vortex generated by the liquid flow at the connection between the suction chamber and the throat pipe in the existing annular jet pump; the cavitation and cavitation damage of the throat surface of the annular jet pump caused by the low pressure at the center of the vortex; Can not fully mix with the working fluid, resulting in loss of fluid flow energy; at the connection between the throat pipe and the diffuser pipe, and the connection between the diffuser pipe and the water outlet pipe, the mixed liquid suddenly turns and causes local head loss. Compared with the existing annular jet pump, the streamlined annular jet pump of the invention has obvious advantages in working performance and working efficiency, and is expected to have further promotion and application prospects in the field of fluid machinery and practical applications.

Description

Streamlined annular jet pump

technical field

The invention relates to a jet pump technology, in particular to a streamlined annular jet pump, which belongs to the technical field of fluid machinery.

Background technique

Jet pump is a kind of conveying machinery and mixing reaction equipment that uses high-speed fluid as working power to pump and transport fluid. The jet pump itself has no moving parts, and it has a series of unique advantages such as simple structure, easy installation, convenient maintenance, good sealing, reliable operation, low cost, and easy comprehensive utilization. Jet pumps have been widely used in water conservancy, metallurgy, petroleum, chemical industry, environmental protection, marine development, nuclear energy utilization, aerospace and other fields; especially suitable for underwater, radiation, corrosion and other dangerous places that are not suitable for people to approach. However, due to the entrainment and mixing of liquid flow inside the jet pump, it is easy to produce large energy loss, so its working efficiency is low, and cavitation and cavitation are prone to occur, which affects the operation of the jet pump and further reduces the efficiency of the system. , and even affect the safe operation of the entire work system.

Jet pumps can be divided into central jet pumps and annular jet pumps according to the positions of their nozzles and suction pipes. The suction pipe of the annular jet pump is arranged at the centerline of its tube axis, and its annular nozzle surrounds the suction pipe to form an annular jet, as shown in Figure 1. The high-pressure working fluid of the annular jet pump rushes into the suction chamber through the annular nozzle, forming a strong entrainment effect on the low-pressure sucked liquid in the suction pipe, and the two fluids are vigorously mixed in the throat pipe and pressurized by the diffusion pipe. , discharged from the outlet pipe, so as to realize the pressurization process. In the existing annular jet pump, the suction chamber is in the form of a conical suction chamber, the throat is in the form of a cylindrical throat, and the diffuser is in the form of a conical diffuser; The connection method of the water pipe adopts the broken line connection. The disadvantages of this structure and connection method of the annular jet pump are: first, in the existing annular jet pump, because the connection between the suction chamber and the throat is a broken line, the pipe wall at this place suddenly turns, The high-speed working fluid will flow away from the wall, and the liquid flow in the throat will fill the area vacated between the high-speed working fluid and the throat wall, forming a vortex. The vortex will lead to the strengthening of the relative motion of the particles inside the liquid flow, which will increase the internal friction of the liquid flow. Because the working fluid has a faster flow rate there, a large local head loss will occur, which will affect the working efficiency of the annular jet pump to transport fluid. Second, a low pressure area will be formed at the center of the vortex, resulting in the segregation of micro-bubbles on the wall of the throat. As the outlet pressure of the jet pump decreases and the flow ratio increases, the number of micro-bubbles on the wall of the throat increases continuously. When the working fluid and the sucked fluid exchange momentum, the pressure in the throat gradually increases, the bubbles on the wall of the throat collapse, and cavitation damage will occur to the wall of the throat; at the same time, the energy of the liquid flow is consumed to make the annular jet flow The performance and operating efficiency of the pump drop dramatically, which in turn shortens the life of the jet pump. Third, the throat of the existing annular jet pump is cylindrical. Due to the high flow rate of the working fluid, in order to reduce the loss along the pipeline, the throat should not be too long, which will lead to insufficient mixing of the sucked liquid and the working fluid in the throat. , the flow of the mixture at the outlet of the throat is uneven. Fourth, in the existing annular jet pump, because the joints between the throat pipe and the diffuser pipe, and the diffuser pipe and the water outlet pipe are all broken lines, the two pipe walls suddenly turn, and the streamline will bend, and the near-wall surface will mix. The liquid flow rate is high, so there will be a certain local head loss, which will affect the working efficiency of the annular jet pump.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the defects and deficiencies existing in the existing annular jet pump structure, to provide a streamlined annular jet pump; the streamlined annular jet pump is a conical suction chamber, Cylindrical throat pipe and conical diffuser pipe are designed as streamlined suction chamber and streamlined mixing pipe respectively; at the same time, the polyline connection methods of suction chamber, throat pipe, diffuser pipe and water outlet pipe used in the existing annular jet pump are designed to be streamlined connection method. Therefore, the local water head loss caused by the vortex generated by the liquid flow at the connection between the suction chamber and the throat pipe in the existing annular jet pump is solved; The energy loss of the liquid flow caused by the insufficient mixing of the sucked liquid and the working liquid; the local head loss caused by the sudden turning of the mixed liquid at the connection between the throat pipe and the diffusion pipe, and the connection between the diffusion pipe and the water outlet pipe.

In order to achieve the above-mentioned purpose of the present invention, the present invention is realized by a technical solution composed of the following technical measures.

The streamlined annular jet pump of the present invention includes a working water pipe, a suction pipe, an annular nozzle, a suction chamber, a throat pipe, a diffuser pipe and a water outlet pipe; according to the present invention, the suction chamber is designed as a streamlined suction chamber; the throat The tube and the diffuser are designed as an integrated streamlined mixing tube, that is, the streamlined mixing tube includes a streamlined throat and a streamlined diffusion tube; and an arc transition tube is designed to streamline the connection between the streamlined mixing tube and the outlet pipe; the working water tube is connected to the annular nozzle, The annular nozzle is connected to the streamlined suction chamber, the water suction pipe is connected to the streamlined suction chamber, and the streamlined suction chamber, the streamlined mixing pipe, the arc transition pipe and the water outlet pipe are sequentially connected in a streamlined manner.

In the above technical solution, the wall surface of the streamlined suction chamber is designed as a circular arc streamlined shape, and the circular arc starts at the outlet of the outer edge wall of the annular nozzle and is tangent to its wall surface; the end of the circular arc is opposite to the inner wall surface of the streamlined mixing tube. connected and tangent to its inner wall.

In the above technical solution, the central angle angle corresponding to the circular arc in the circular arc streamline of the streamlined suction chamber is α/2, and its mathematical expression is as follows:

R=L×cot(α/4)

where α and L are the contraction angle and length of the suction chamber of the existing annular jet pump, respectively; R is the arc radius of the streamlined suction chamber.

In the above technical solution, the inner wall surface of the streamlined mixing pipe is designed to be streamlined, and the streamlined linear shape starts at the outlet of the streamlined suction chamber inner wall surface and is tangent to its inner wall surface; the end of the streamlined linear shape starts from the inner wall surface of the arc transition pipe. connected at the beginning and tangent to its inner wall; the mathematical expression of the streamlined line is as follows:

L _td =(4～7)D _t β=8°～12° y=±(D _t /2+x ⁿ )

Where: L _td is the axial length of the streamlined mixing tube; D _t is the pipe diameter at the inlet of the streamlined mixing tube; β is the diffusion angle at the outlet of the streamlined mixing tube; y is the longitudinal coordinate of the streamlined line; x is the axial coordinate of the streamline; n is the index, and its value ranges from 2.5 to 5.

In the above technical solution, the inner wall surface of the arc transition pipe is designed as a circular arc streamline, and the arc starts at the end of the inner wall surface of the streamlined mixing pipe and is tangent to its inner wall surface; the end of the arc is in contact with the inner wall surface of the inlet of the water outlet pipe. connected and tangent to its inner wall.

The streamlined annular jet pump of the present invention has the following advantages and beneficial technical effects:

1. The streamlined annular jet pump of the present invention, the conical suction chamber of the existing annular jet pump is designed as a streamlined suction chamber, and the cylindrical throat pipe and the conical diffuser pipe are designed as a streamlined mixing tube; Some folded-line connections; at the connection between the streamlined suction chamber and the streamlined mixing pipe, the high-speed working fluid flows smoothly along the wall to avoid separation and flow to form vortices, which can reduce the local head loss and help improve the working performance of the annular jet pump .

2. According to the streamlined annular jet pump of the present invention, the high-speed working fluid in the jet pump will not flow away from the wall at the connection between the streamlined suction chamber and the streamlined mixing pipe, thereby eliminating the local low pressure area and avoiding the annular shape caused by the sudden change in the boundary. Cavitation and cavitation damage on the wall of the jet pump.

3. In the streamlined annular jet pump of the present invention, in the streamlined mixing tube, since the mixed liquid flows smoothly along the wall surface, the local water head loss can be reduced, and the working efficiency of the annular jet pump can also be improved; The aspirated liquid and the working liquid can be more fully mixed, so that the mixed liquid at the outlet flows more uniformly, thereby reducing the diffusion loss of the mixed liquid.

4. In the streamlined annular jet pump of the present invention, the connection between the streamlined mixing pipe and the water outlet pipe is streamlined connection, and the mixed liquid in the mixing pipe can smoothly flow into the water outlet pipe along the wall of the arc transition pipe to avoid mixing there. The local head loss caused by the sudden change of liquid flow direction also helps to improve the working performance of the annular jet pump.

5. Compared with the existing annular jet pump, the streamlined annular jet pump of the present invention has a The broken line connection mode of the pipe, the diffuser pipe and the water outlet pipe is a streamlined connection mode; and the existing numerical control processing technology can be realized, so that the streamlined annular jet pump of the present invention has obvious advantages in improving the working performance, and is expected to be used in the field of fluid machinery. And there are further promotion and application prospects in practical applications.

Description of drawings

Fig. 1 is the sectional structure schematic diagram of the existing annular jet pump;

Fig. 2 is the sectional structure schematic diagram of the streamlined annular jet pump of the present invention;

FIG. 3 is an enlarged cross-sectional structural schematic diagram of the streamlined mixing tube of the streamlined annular jet pump in FIG. 2 .

In the figure: 1 working water pipe; 2 suction pipe; 3 annular nozzle; 4 suction chamber; 5 streamlined suction chamber; 6 throat pipe; 7 diffusion pipe; 8 streamlined mixing pipe; 9 arc transition pipe; 10 water outlet pipe.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but it is not intended to limit the protection scope of the present invention.

The streamlined annular jet pump of the present invention has a cross-sectional structure as shown in Figure 2, including a working water pipe 1, a suction pipe 2, an annular nozzle 3, a streamlined suction chamber 5, and a streamlined mixing pipe 8 including a throat pipe and a diffuser pipe. , the arc transition pipe 9 and the water outlet pipe 10; the working water pipe 1 is connected to the annular nozzle 3, the annular nozzle 3 is connected to the streamlined suction chamber 5, the water suction pipe 2 is connected to the streamlined suction chamber 5, and the streamlined suction chamber 5, streamlined The mixing pipe 8, the arc transition pipe 9 and the water outlet pipe 10 are sequentially connected in a streamlined manner.

The wall surface of the streamlined suction chamber 5 is designed as a circular arc streamlined shape, the circular arc starts at the outlet of the outer edge wall surface of the annular nozzle 3 and is tangent to its wall surface, and the end of the circular arc is connected with the inner wall surface of the streamlined mixing tube 8 and Tangent to its inner wall surface; the inner wall surface of the streamlined mixing tube 8 is designed to be streamlined, and the streamlined linear shape starts at the outlet of the streamlined suction chamber 5 and is tangent to its inner wall surface, and the end of the streamlined linear shape is connected to the arc transition pipe. 9, the arc inner wall surface is connected at the beginning and is tangent to its inner wall surface; the streamlined mixing pipe 8 and the water outlet pipe 10 are connected by a circular arc transition pipe 9, and the circular arc starts in the streamlined mixing pipe 8. The end of the wall is tangent to its inner wall, and the end of the arc is connected to and tangent to the inner wall of the inlet of the water outlet pipe 10 .

In Fig. 3, since the throat and the diffuser are designed as an integrated streamlined mixing tube 8, the inner wall of the streamlined mixing tube is designed to be streamlined, so the mixed liquid can flow smoothly along the wall of the streamlined mixing tube, which can reduce the local head loss, Helps to improve the working efficiency of the annular jet pump.

Example

According to the experimental research results of the existing annular jet pump, when the streamlined annular jet pump is used in combination with the present embodiment, the constriction angle of the suction chamber 4 is taken as α=20°, and the area ratio of the jet pump, that is, the inlet area of the streamlined mixing tube 8 and the The ratio of the outlet area of the annular nozzle 3 is taken as 2.22; the diameter of the suction pipe 2 is taken as 44mm.

The central angle of the arc in the streamlined suction chamber 5 is taken as 10°, and the suction chamber length L in the suction chamber 4 is taken as 43mm. According to the mathematical expression corresponding to the arc in the aforementioned streamlined suction chamber 5 arc streamlined R=L×cot(α/4), it can be obtained that its arc radius R is taken as 491.5mm; the diameter D _t at the inlet of the streamlined mixing tube 8 is taken as 40mm; according to the mathematical expression of the aforementioned streamlined line, L _td = (4～7) D _t , combined with practical experience, the axial length L _td of the streamlined mixing tube 8 can be taken as 200 mm. According to the mathematical expression of the streamlined linear shape, β=8°～12°, combined with practical experience, the streamlined type can be obtained. The diffusion angle at the outlet of the mixing tube 8 is taken as β=10°, and the exponent n in the mathematical expression y=±(D _t /2+x ⁿ ) of the streamlined linear shape is taken as 3.25, and the streamlined shape can be obtained according to the mathematical expression The diameter D _td at the outlet of the mixing pipe 8 is 50.8 mm; the arc transition pipe 9 connects the streamlined mixing pipe 8 and the water outlet pipe 10 ; the diameter of the water outlet pipe 10 is 60 mm.

The working process of the streamlined annular jet pump described in this embodiment is as follows:

The streamlined annular jet pump with the structure shown in Figure 2, when the streamlined annular jet pump works, its high-speed working fluid is sprayed through the annular nozzle 3, and the ejected working fluid entrains the sucked liquid in the suction pipe 2 and mixes with the sucked liquid. Contact with the streamlined suction chamber 5, and then smoothly enter the streamlined mixing tube 8 along the wall of the streamlined suction chamber and mix in the streamlined mixing tube to perform energy exchange, and at the same time gradually reduce the speed of the mixed liquid and increase the pressure, and then the mixed liquid transitions along the arc The wall surface of the pipe 9 enters the water outlet pipe 10 smoothly, and finally discharges through the water outlet pipe.

Through this embodiment, the streamlined annular jet pump makes the high-speed working fluid flow smoothly along the wall at the connection between the streamlined suction chamber and the streamlined mixing tube in a streamlined manner, thereby avoiding the formation of vortices, reducing local head loss, and helping Improve the working performance of the annular jet pump and improve the working efficiency of the annular jet pump; at the same time, the high-speed working fluid in the annular jet pump will not flow away from the wall at the streamlined connection between the streamlined suction chamber and the streamlined mixing tube, thus eliminating the local low pressure area. , which can avoid the cavitation and cavitation damage of the annular jet pump wall caused by the sudden change of the boundary, so it helps to improve the cavitation performance of the annular jet pump and prolong the service life of the jet pump; The working fluid can be fully mixed, so that the mixed liquid at the outlet of the mixing tube flows more uniformly; in addition, because the connection between the streamlined mixing tube and the water outlet pipe is replaced by the existing broken line connection, the mixed liquid in the streamlined mixing tube can be The water flows smoothly into the outlet pipe along the wall of the arc transition pipe, thereby reducing the local head loss there, which also helps to improve the working performance of the annular jet pump and the working efficiency of the annular jet pump.

Claims (5)

1. A streamlined annular jet pump, comprising a working water pipe (1), a suction pipe (2), an annular nozzle (3), a suction chamber (4), a throat pipe (6), a diffuser pipe (7) and a water outlet pipe (10) ); It is characterized in that the suction chamber is designed as a streamlined suction chamber (5), and the throat pipe and the diffuser are designed as an integrated streamlined mixing pipe (8), that is, the streamlined mixing pipe includes a streamlined throat and a streamlined diffusion pipe; And A circular arc transition pipe (9) is designed to connect the streamlined mixing pipe and the water outlet pipe in a streamlined manner; the working water pipe is connected to an annular nozzle, the annular nozzle is connected to the streamlined suction chamber, the suction pipe is connected to the streamlined suction chamber, the streamlined suction chamber, the streamlined suction chamber, and the streamlined suction chamber. The mixing pipe, the arc transition pipe and the water outlet pipe are connected in a streamlined sequence. 2. The streamlined annular jet pump according to claim 1, characterized in that the inner wall surface of the streamlined suction chamber (5) is designed as an arc streamline, and the arc starts at the outlet of the outer edge wall of the annular nozzle (3). and is tangent to its wall surface; the end of the arc is connected to and tangent to the inner wall surface of the streamlined mixing tube (8). 3. according to the described streamlined annular jet pump of claim 1 and 2, it is characterized in that the central angle angle corresponding to its circular arc is α/2 in the circular arc streamline of described streamlined suction chamber (5), and its mathematical expression is as follows: R=L×cot(α/4) where α and L are the contraction angle and length of the suction chamber of the existing annular jet pump, respectively; R is the arc radius of the streamlined suction chamber. 4. The streamlined annular jet pump according to claim 1 is characterized in that the inner wall surface of the streamlined mixing tube (8) is designed to be streamlined, and the streamlined linear shape starts at the outlet of the inner wall surface of the streamlined suction chamber (5) and is connected with it. The inner wall surface is tangent; the end of the streamlined line is connected with the beginning of the inner wall surface of the arc transition pipe (9) and is tangent to its inner wall surface; the streamlined linear mathematical expression is as follows: L _td =(4～7)D _t β=8°～12°y=±(D _t /2+x ⁿ ) Where: L _td is the axial length of the streamlined mixing tube; D _t is the pipe diameter at the inlet of the streamlined mixing tube; β is the diffusion angle at the outlet of the streamlined mixing tube; y is the longitudinal coordinate of the streamlined line; x is the axial coordinate of the streamline; n is the index, and its value ranges from 2.5 to 5. 5. The streamlined annular jet pump according to claim 1, characterized in that the inner wall surface of the arc transition pipe (9) is designed as an arc streamline, and the arc starts at the end of the inner wall surface of the streamline mixing pipe (8). It is tangent to its inner wall surface, and the end of the arc is connected to the inner wall surface of the inlet of the water outlet pipe (10) and is tangent to its inner wall surface.

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