CN115247657B - Self-circulation jet anti-cavitation structure and centrifugal pump with same - Google Patents
Self-circulation jet anti-cavitation structure and centrifugal pump with same Download PDFInfo
- Publication number
- CN115247657B CN115247657B CN202111608524.5A CN202111608524A CN115247657B CN 115247657 B CN115247657 B CN 115247657B CN 202111608524 A CN202111608524 A CN 202111608524A CN 115247657 B CN115247657 B CN 115247657B
- Authority
- CN
- China
- Prior art keywords
- jet
- flow
- water level
- level monitoring
- impeller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/18—Rotors
- F04D29/22—Rotors specially for centrifugal pumps
- F04D29/2238—Special flow patterns
- F04D29/2255—Special flow patterns flow-channels with a special cross-section contour, e.g. ejecting, throttling or diffusing effect
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/18—Rotors
- F04D29/22—Rotors specially for centrifugal pumps
- F04D29/2261—Rotors specially for centrifugal pumps with special measures
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention provides a self-circulation jet flow anti-cavitation structure and a centrifugal pump with the same, belongs to the technical field of centrifugal pumps, and is used for solving the problem of poor anti-cavitation performance of the conventional centrifugal pump. The self-circulation cavity structure formed by the liquid storage tank and the flow through pipe is arranged on the outer side of the impeller rim, the flow through pipe, the liquid storage tank and the jet holes enable the outer side of the impeller rim to form a communicated high-pressure loop system, the communication under different working conditions is achieved by controlling the opening and closing of the first jet holes and the second jet holes, the flow of an impeller outlet runner flows into the liquid storage tank through the communicating pipe, and then the flow of the impeller outlet runner is injected into an impeller inlet runner through the jet holes at different positions, so that the effect of applying jet flow to a flow field is generated, compensation on the flow separation area of the front edge of the blade under different working conditions can be achieved, self-adjustment is achieved, and therefore cavitation problems caused by eccentric working condition operation of the centrifugal pump are effectively solved, and the operation stability of the centrifugal pump is improved; the jet structure is not needed to be externally added, the structure is simple, and the implementation is easy.
Description
Technical Field
The invention belongs to the technical field of centrifugal pumps, and relates to a self-circulation jet anti-cavitation structure and a centrifugal pump with the same.
Background
The centrifugal pump mainly comprises a centrifugal impeller and a volute, wherein the centrifugal impeller is a main core component of the centrifugal pump, an impeller outlet is connected with the volute, and a gap exists between the centrifugal impeller and the volute. When the centrifugal pump works, the rotating impeller does work on the liquid flow, so that the speed, the pressure and the like of the liquid flow are increased, and the high lift is obtained. When the running flow of the centrifugal pump is smaller than the design flow, a positive attack angle appears at the inlet of the impeller, and the pressure of the suction surface of the blade is reduced to the local vaporization pressure so as to cause cavitation; when the running flow is greater than the design flow, a negative attack angle appears at the inlet of the impeller, and cavitation can be caused by the fact that the pressure of the pressure surface of the blade is reduced to the local vaporization pressure; however, no matter in a large-flow working condition or a small-flow working condition, the operation efficiency of the centrifugal pump can be influenced as long as cavitation occurs in the centrifugal pump, and vibration and noise are caused; when the cavitation is serious, the overcurrent component of the centrifugal pump can be damaged, and the running stability and reliability of the centrifugal pump are affected.
The inducer is added in front of the centrifugal impeller, which is the most common method for solving the cavitation problem of the centrifugal pump, and the cavitation problem of the centrifugal pump is solved by increasing the inlet pressure of the impeller. However, this approach not only increases the centrifugal pump size, but also requires consideration of the interaction of the inducer with the centrifugal impeller. In addition, the inducer itself also needs to have a strong anti-cavitation capability to ensure stable operation of the whole centrifugal pump.
Therefore, a self-circulation jet structure which has a simple structure and can effectively solve the cavitation problem of the centrifugal pump caused by the operation condition on the premise of not adding additional flow components is needed.
Disclosure of Invention
The invention aims at solving the problems in the prior art, and provides a self-circulation jet flow anti-cavitation structure and a centrifugal pump with the anti-cavitation structure, and the invention aims at solving the technical problems that: and improving the cavitation resistance of the centrifugal pump on the premise of not adding additional flow components. The self-circulation jet flow anti-cavitation structure can improve the pressure of the pressure surface of the blade when the flow is large and improve the pressure of the suction surface of the blade when the flow is small, so that the cavitation problem of the centrifugal pump caused by the operation of the eccentric working condition is effectively solved, and the operation stability of the centrifugal pump is improved.
The aim of the invention can be achieved by the following technical scheme:
the self-circulation jet flow cavitation-resistant structure comprises an impeller, wherein the impeller comprises an impeller rim, a rear cover plate, a front cover plate, blades and a water level monitoring connecting seat, the water level monitoring connecting seat and the front cover plate are respectively arranged at two ends of the impeller rim, the rear cover plate is positioned at the outer side of the front cover plate, a hub is arranged at the middle part of the impeller, the middle part of each blade is connected with the hub, the blades are positioned between the rear cover plate and the front cover plate, an impeller outlet runner is arranged between the rear cover plate and the front cover plate, and an impeller inlet runner is arranged at one side of the impeller, which is positioned at the water level monitoring connecting seat; a plurality of liquid storage tanks and flow through pipes are arranged on the outer side of the impeller rim, the upper parts of the liquid storage tanks are communicated with the impeller outlet flow channels through the flow through pipes, a plurality of jet holes are formed in the impeller inlet flow channels, and the liquid storage tanks are communicated with the jet holes through the jet pipes; the two jet holes are a group, namely a first jet hole and a second jet hole in sequence according to the flow direction of liquid flow, the axial distribution areas of the first jet hole and the second jet hole in the same group are positioned near the front edge of the blade, the circumferential distribution of the first jet hole and the second jet hole is arranged according to the jet direction, wherein the first jet hole is ejected towards the suction surface of the blade, and the second jet hole is ejected towards the front edge of the blade and the pressure surface; the liquid storage tank is provided with a shielding slide block in a sliding manner, a switch of the first jet hole and the second jet hole is controlled by the shielding slide block, a through hole corresponding to the jet hole is formed in the shielding slide block, a water level monitoring cavity is formed in the water level monitoring connecting seat, a plurality of water level monitoring floating slide blocks are slidably arranged in the water level monitoring cavity, the water level monitoring floating slide blocks are connected with the shielding slide blocks through connecting rods, the water level monitoring floating slide blocks keep a low liquid level state when the small flow working condition is met, the shielding slide blocks enable the first jet hole to be opened, the second jet hole is closed, the water level monitoring floating slide blocks keep a high liquid level state when the large flow working condition is met, and the water level monitoring floating slide blocks drive the shielding slide blocks to move, so that the first jet hole is closed, and the second jet hole is opened.
The working principle of the invention is as follows: the self-circulation cavity structure formed by the liquid storage tank and the draft tube is arranged on the outer side of the impeller rim, the draft tube, the liquid storage tank and the jet holes enable the outer side of the impeller rim to form a communicated high-pressure loop system, a liquid inlet of the liquid storage tank is communicated with an impeller outlet flow channel through the draft tube, a liquid outlet of the liquid storage tank is communicated with jet holes formed in an impeller inlet flow channel through the jet tubes, the two jet holes are in a group, jet directions of the first jet holes and the second jet holes are different, the first jet holes jet towards a suction surface of a blade, the second jet holes jet towards the front edge of the blade and a pressure surface, the flow of the impeller outlet flow channel flows into the liquid storage tank through the draft tube, and then jet holes at different positions jet into the impeller inlet flow channel, so that jet flow is applied to the flow field, a certain pressure is generated on different surfaces of the blade according to different flow working conditions, and cavitation resistance is improved; under different flow working conditions, the positions of the water level monitoring floating sliding blocks at the impeller inlet flow channels are different, the blocking sliding blocks are driven to move by the displacement of the water level monitoring floating sliding blocks, the blocking sliding blocks can be switched on and off at the jet holes at different positions in the liquid storage tank, and accordingly the switch of the first jet holes and the switch of the second jet holes can be automatically controlled, and different jet effects are formed.
The jet holes are sequentially arranged along the axial direction, the second jet holes are positioned on the outer sides of the first jet holes, the axial positions of all the first jet holes are the same in different jet hole groups, the axial positions of all the second jet holes are the same, the second jet holes are guaranteed to jet towards the head part and the working face of the blade, and the first jet holes are guaranteed to jet towards the suction face of the blade.
The jet hole groups are uniformly distributed in the circumferential direction, and the number of the hole groups is an integer multiple of the number of the blades; preferably, the number of the blades is six, and the number of the jet hole groups is twelve; by adopting the structure, the damage of the circumferential uniformity of the flow field of the centrifugal pump caused by the circumferential non-uniformity of jet flow can be avoided.
The middle part of the hub is provided with a pump shaft mounting hole, the front cover plate is provided with a plurality of through holes connected with the through flow pipes, and the through holes are uniformly distributed in circumference; part of water in the impeller outlet flow passage flows into the liquid storage tank through the draft tube, and is injected into the impeller inlet flow passage through the jet hole, so that a self-circulation high-pressure jet loop is formed.
The inside of water level monitoring connecting seat has been seted up a plurality of water level monitoring cavities, and the quantity of water level monitoring cavity corresponds the setting with the quantity of liquid reserve tank, and the outside of water level monitoring connecting seat is provided with the flange, and the sliding of water level monitoring floating slide block sets up in the water level monitoring cavity, and the spacing groove has been seted up to one side of water level monitoring cavity, and the one side of water level monitoring floating slide block wears out spacing groove and one end of connecting rod and articulates, and the other end of connecting rod articulates with shielding the slider.
In order to realize the automatic control of the working states of the first jet hole and the second jet hole, an adjustable shielding sliding block is arranged in the liquid storage tank; when the working condition of small flow is met, the shielding sliding block is controlled to enable the first jet hole to work and the second jet hole to be blocked; and under the working condition of large flow, the shielding sliding block is controlled to enable the second jet hole to work and the first jet hole to be blocked.
The shielding slide block adopts any structure, so long as the functions can be realized.
The shielding slide block is of a slide block structure which is in sliding connection with the liquid storage tank, and the length of the shielding slide block is designed to be matched with the width of the liquid storage tank, the first jet hole, the second jet hole and the circumferential position of the water level monitoring cavity. The aperture of the through hole arranged on the shielding slide block is slightly larger than that of the first jet hole. The left side length of shielding slider trompil equals the distance between first efflux hole and the liquid reserve tank left side wall face, and when the low discharge operating mode, guarantee through-hole and first efflux hole intercommunication, shielding second efflux hole, and when the high flow operating mode, shielding the through-hole and the second efflux hole intercommunication of seting up on the slider, shielding first efflux hole.
Each group of jet holes are independently arranged, and liquid storage tanks above different jet hole groups are not communicated with each other.
The first and second jet holes are oriented in a selected manner depending on the extent of the vane leading edge pressure and suction side flow separation regions to optimize impingement flow separation center position.
The size of the opening of the jet hole is required to be compatible with two working conditions of large flow and small flow. Preferably, the jet aperture diameter is in the range of 0.4mm to 1.0mm. In the low-flow working condition, the total jet flow of the jet holes is controlled to be 4% -8% of the total flow of the impeller so as to reduce the influence of the jet self-circulation loop on the performance of the centrifugal pump, and in order to form high-speed jet flow, the diameter of the opening of the first jet hole is required to be smaller. And in the high-flow working condition, the total jet flow can be controlled to be 6% -10% of the total flow, and in order to form stable jet flow, the diameter of the opening of the second jet hole is required to be properly increased. In addition, the diameters of the openings of the first jet holes and the second jet holes are determined according to the number of the circumferential jet hole groups.
The centrifugal pump with the anti-cavitation structure adopts the self-circulation jet anti-cavitation structure in the centrifugal pump impeller, so that the flow separation area at the front edge of the blade is compensated under different working conditions, the cavitation problem of the centrifugal pump caused by the operation of the eccentric working conditions is effectively solved, and the operation stability of the centrifugal pump is improved.
Compared with the prior art, the self-circulation jet anti-cavitation structure and the centrifugal pump with the anti-cavitation structure have the following advantages:
1. the self-circulation cavity structure formed by a liquid storage tank and a draft tube is arranged at the outer side of the impeller rim, the draft tube, the liquid storage tank and the jet holes enable the outer side of the impeller rim to form a communicated high-pressure loop system, a liquid inlet of the liquid storage tank is communicated with an impeller outlet runner through the draft tube, a liquid outlet of the liquid storage tank is communicated with the jet holes arranged in an impeller inlet runner through the jet tubes, the two jet holes are in a group, jet directions of the first jet hole and the second jet hole are different, the first jet hole is jet towards the suction surface of the blade, and the second jet hole is jet towards the front edge and the pressure surface of the blade; through controlling opening and closing of the first jet hole and the second jet hole, communication under different working conditions is achieved, flow of the impeller outlet flow channel flows into the liquid storage tank through the draft tube, jet flows into the impeller inlet flow channel through the jet holes at different positions, jet flow is applied to the flow field, certain pressure is generated on different faces of the impeller according to different flow working conditions, self-adjustment is achieved, and anti-cavitation performance is improved. The flow separation area at the front edge of the blade can be compensated under different working conditions, the pressure of the pressure surface of the blade can be improved when the flow is high, and the pressure of the suction surface of the blade can be improved when the flow is low, so that the cavitation problem of the centrifugal pump caused by the operation of the eccentric working condition is effectively solved, and the operation stability of the centrifugal pump is improved; and the jet structure is not needed to be externally added, the structure is simple, and the implementation is easy.
2. The high-flow working condition and the low-flow working condition can be met through the arrangement of the positions of the first jet hole and the second jet hole in a matched shielding relation. The liquid storage tank is provided with a shielding slide block in a sliding manner, a switch of the first jet hole and the second jet hole is controlled by the shielding slide block, a through hole corresponding to the jet hole is formed in the shielding slide block, a water level monitoring cavity is formed in the water level monitoring connecting seat, a plurality of water level monitoring floating slide blocks are slidably arranged in the water level monitoring cavity, the water level monitoring floating slide blocks are connected with the shielding slide blocks through connecting rods, the water level monitoring floating slide blocks keep a low liquid level state when the small flow working condition is met, the shielding slide blocks enable the first jet hole to be opened, the second jet hole is closed, the water level monitoring floating slide blocks keep a high liquid level state when the large flow working condition is met, and the water level monitoring floating slide blocks drive the shielding slide blocks to move, so that the first jet hole is closed, and the second jet hole is opened. Under different flow working conditions, the positions of the water level monitoring floating sliding blocks at the impeller inlet flow channels are different, the blocking sliding blocks are driven to move by the displacement of the water level monitoring floating sliding blocks, the blocking sliding blocks can be switched on and off at the jet holes at different positions in the liquid storage tank, and accordingly the switch of the first jet holes and the switch of the second jet holes can be automatically controlled, and different jet effects are formed.
Drawings
FIG. 1 is a schematic view of the front axle side structure of the present invention;
FIG. 2 is a rear axle side structural schematic of the present invention;
FIG. 3 is a schematic diagram of the front view of the present invention;
FIG. 4 is a schematic rear view of the present invention;
FIG. 5 is a schematic cross-sectional view of section A-A of FIG. 4;
FIG. 6 is a schematic side elevational view of the present invention;
FIG. 7 is a schematic cross-sectional view of section B-B of FIG. 6;
FIG. 8 is a schematic perspective view of FIG. 7;
FIG. 9 is a schematic diagram of the operation of the jet orifice in a low flow condition;
FIG. 10 is a schematic illustration of the operation of the jet orifice in a high flow condition;
in the figure: 1-impeller rim, 2-back cover plate, 3-front cover plate, 4-blade, 5-liquid storage tank, 6-draft tube, 7-impeller outlet runner, 8-water level monitoring connecting seat, 9-impeller inlet runner, 10-water level monitoring floating slide block, 11-first jet hole, 12-second jet hole, 13-hub, 14-flange, 15-connecting rod, 16-draft hole, 17-pump shaft mounting hole, 18-water level monitoring cavity, 19-shielding slide block, 20-jet tube.
Detailed Description
The technical scheme of the patent is further described in detail below with reference to the specific embodiments.
Embodiments of the present patent are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present patent and are not to be construed as limiting the present patent.
In the description of this patent, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the patent and simplify the description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be configured and operated in a particular orientation, and are therefore not to be construed as limiting the patent.
In the description of this patent, it should be noted that, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "disposed" are to be construed broadly, and may be fixedly connected, disposed, detachably connected, disposed, or integrally connected, disposed, for example. The specific meaning of the terms in this patent will be understood by those of ordinary skill in the art as the case may be.
Referring to fig. 1-10, the present embodiment provides a self-circulation jet anti-cavitation structure, which comprises an impeller, wherein the impeller comprises an impeller rim 1, a back cover plate 2, a front cover plate 3, blades 4 and a water level monitoring connecting seat 8, the water level monitoring connecting seat 8 and the front cover plate 3 are respectively arranged at two ends of the impeller rim 1, the back cover plate 2 is positioned at the outer side of the front cover plate 3, a hub 13 is arranged at the middle part of the impeller, the middle part of the blades 4 is connected with the hub 13, the blades 4 are positioned between the back cover plate 2 and the front cover plate 3, an impeller outlet runner 7 is arranged between the back cover plate 2 and the front cover plate 3, and an impeller inlet runner 9 is arranged at one side of the water level monitoring connecting seat 8 in the impeller; a plurality of liquid storage tanks 5 and flow through pipes 6 are arranged on the outer side of the impeller rim 1, the upper parts of the liquid storage tanks 5 are communicated with an impeller outlet flow passage 7 through the flow through pipes 6, a plurality of jet holes are formed in an impeller inlet flow passage 9, and the liquid storage tanks 5 are communicated with the jet holes through jet pipes 20; the two jet holes are a group, namely a first jet hole 11 and a second jet hole 12 in sequence according to the flow direction of liquid flow, the axial distribution areas of the first jet hole 11 and the second jet hole 12 in the same group are positioned near the front edge of the blade 4, the circumferential distribution of the first jet hole 11 and the second jet hole 12 is set according to the jet direction, wherein the first jet hole 11 is ejected towards the suction surface of the blade, and the second jet hole 12 is ejected towards the front edge and the pressure surface of the blade; the liquid storage tank 5 is provided with a shielding slide block 19 in a sliding manner, the first jet hole 11 and the second jet hole 12 are controlled by the shielding slide block 19, a through hole corresponding to the jet hole is formed in the shielding slide block 19, a water level monitoring cavity 18 is formed in the water level monitoring connecting seat 8, a plurality of water level monitoring floating slide blocks 10 are arranged in the water level monitoring cavity 18 in a sliding manner, the water level monitoring floating slide blocks 10 are connected with the shielding slide block 19 through a connecting rod 15, the water level monitoring floating slide blocks 10 keep a low liquid level state in a small flow working condition, the shielding slide blocks 19 enable the first jet hole 11 to be opened and the second jet hole 12 to be closed, the water level monitoring floating slide blocks 10 keep a high liquid level state in a large flow working condition, and the water level monitoring floating slide blocks 10 drive the shielding slide blocks 19 to move so that the first jet hole 11 is closed and the second jet hole 12 is opened.
The self-circulation cavity structure formed by the liquid storage tank 5 and the draft tube 6 is arranged on the outer side of the impeller rim 1, the draft tube 6, the liquid storage tank 5 and the jet holes enable the outer side of the impeller rim 1 to form a communicated high-pressure loop system, a liquid inlet of the liquid storage tank 5 is communicated with an impeller outlet flow channel 7 through the draft tube 6, a liquid outlet of the liquid storage tank 5 is communicated with jet holes formed in an impeller inlet flow channel 9 through jet tubes 20, the two jet holes are a group, jet directions of a first jet hole 11 and a second jet hole 12 are different, the first jet hole 11 is ejected towards the suction surface of the blade 4, the second jet hole 12 is ejected towards the front edge and the pressure surface of the blade 4, communication under different working conditions is achieved by controlling the opening and closing of the first jet hole 11 and the second jet hole 12, flow of the impeller outlet flow channel 7 flows into the liquid storage tank 5 through the draft tube 6, jet holes at different positions are ejected into the impeller inlet flow channel 9, so that jet flow is applied to the flow field, a certain pressure is generated to different surfaces of the blade according to different working conditions, cavitation resistance is improved; under different flow working conditions, the positions of the water level monitoring floating slide blocks 10 at the impeller inlet flow channel 9 are different, the blocking slide blocks 19 are driven to move by the displacement of the water level monitoring floating slide blocks 10, and the blocking slide blocks 19 can be switched on and off at the jet holes at different positions in the liquid storage tank 5, so that the switching of the first jet holes 11 and the second jet holes 12 can be automatically controlled, and different jet effects are formed.
The jet holes are sequentially arranged along the axial direction, the second jet holes 12 are positioned on the outer sides of the first jet holes 11, the axial positions of all the first jet holes 11 are the same in different jet hole groups, the axial positions of all the second jet holes 12 are the same, the second jet holes 12 are guaranteed to jet towards the head and the working face of the blade 4, and the first jet holes 11 are guaranteed to jet towards the suction face of the blade 4.
In order to avoid the damage of the circumferential uniformity of the flow field of the centrifugal pump caused by the circumferential non-uniformity of jet flow, the jet hole groups are uniformly distributed in the circumferential direction, and the number of the hole groups is an integer multiple of the number of blades. Preferably, in this embodiment, the number of blades is six, and the number of jet hole sets is twelve. If the circumferentially uneven control of the flow field is to be realized, a circumferentially uneven arrangement mode of jet hole sets can also be adopted.
The middle part of the hub 13 is provided with a pump shaft mounting hole 17, the front cover plate 3 is provided with a plurality of through holes 16 connected with the through flow pipes 6, the through holes 16 are uniformly distributed in circumference, in the embodiment, the number of the liquid storage tank 5 and the through flow pipes 6 is twelve, and the number of the through holes 16 is twelve correspondingly. Part of the water in the impeller outlet flow passage 7 flows into the liquid storage tank 5 through the draft tube 6, and is injected into the impeller inlet flow passage 9 through the jet hole, so that a self-circulation high-pressure jet loop is formed.
The inside of water level monitoring connecting seat 8 has been seted up a plurality of water level monitoring cavity 18, the quantity of water level monitoring cavity 18 corresponds the setting with the quantity of liquid reserve tank 5, in this embodiment, the quantity of water level monitoring cavity 18 is twelve, the outside of water level monitoring connecting seat 8 is provided with flange 14, the slip of water level monitoring floating slide 10 sets up in water level monitoring cavity 18, the spacing groove has been seted up to one side of water level monitoring cavity 18, the spacing groove is worn out to one side of water level monitoring floating slide 10 and is articulated with the one end of connecting rod 15, the other end of connecting rod 15 is articulated with shielding slide 19.
In order to realize the automatic control of the working states of the first jet hole 11 and the second jet hole 12, an adjustable shielding slide block 19 is arranged in the liquid storage tank 5; in a low flow condition, the shielding slide block 19 is controlled to enable the first jet hole 11 to work and the second jet hole 12 to be blocked; during high flow conditions, the shutter slider 19 is controlled such that the second orifice 12 is operated and the first orifice 11 is blocked.
The shielding slider 19 may be of any structure as long as the above-described function is achieved. Preferably, in this embodiment, the shielding slider 19 is a slider structure slidably connected to the liquid storage tank 5, and the length of the shielding slider 19 is designed to match the width of the liquid storage tank 5, the first jet hole 11, the second jet hole 12, and the circumferential position of the water level monitoring cavity 18. The aperture of the through hole formed on the shielding slide block 19 is slightly larger than the aperture of the first jet hole 11. The left side length of the opening of the shielding slide block 19 is equal to the distance between the first jet hole 11 and the left side wall surface of the liquid storage tank 5, the through hole is guaranteed to be communicated with the first jet hole 11 under the low-flow working condition, the second jet hole 12 is shielded, and the through hole formed in the shielding slide block 19 is communicated with the second jet hole 12 under the high-flow working condition, so that the first jet hole 11 is shielded.
Each group of jet holes is independently arranged, and the liquid storage tanks 5 above different jet hole groups are not communicated with each other.
As shown in fig. 9, when the centrifugal pump operates under the low flow condition, the inlet of the vane 4 generates a positive attack angle, the liquid flow impacts on the pressure surface of the vane, the pressure of the suction surface of the vane is reduced, flow separation occurs, and cavitation phenomenon occurs when the pressure of the low pressure area of the suction surface of the vane is reduced to the vaporization pressure of the medium. In the low flow working condition, because the flow in the impeller inlet flow channel 9 is smaller, the water level monitoring cavity 18 is in a low liquid level state, the water level monitoring floating sliding block 10 descends along with the water level, the connecting rod 9 drives the shielding sliding block 19 to move left, the through hole on the shielding sliding block 19 is communicated with the first jet hole 11, the second jet hole 12 is in a closed state, and high-pressure liquid flow sprayed from the first jet hole 11 to the suction surface of the blade compensates the low pressure of the suction surface of the blade 4, so that the pressure of the low-pressure area is increased to be higher than the vaporization pressure of the liquid, and cavitation of the suction surface of the blade 4 is relieved.
As shown in fig. 10, when the centrifugal pump operates under a high-flow condition, a negative attack angle is generated at the inlet of the blade 4, the liquid flow impacts the suction surface of the blade 4, the pressure of the pressure surface of the blade 4 is reduced, flow separation occurs, and cavitation occurs when the pressure of the pressure surface of the blade 4 is reduced to the vaporization pressure of the medium. Under the working condition of large flow, as the flow in the impeller inlet flow channel 9 is large, the liquid level in the water level monitoring cavity 18 rises, the water level monitoring floating sliding block 10 moves upwards under the action of buoyancy, the water level monitoring floating sliding block 10 drives the connecting rod 15 to move upwards, the connecting rod 15 drives the shielding sliding block 19 to move rightwards, the through hole on the shielding sliding block 19 is communicated with the second jet hole 12, the first jet hole 11 is in a closed state, and high-pressure fluid sprayed from the second jet hole 12 to the head of the blade 4 and the pressure surface of the blade compensates the low pressure at the position, so that cavitation of the pressure surface of the blade is relieved.
The orientation of the first and second jet holes 11, 12 is selected depending on the extent of the pressure and suction side flow separation regions of the leading edge of the blade 4, to optimize the impingement flow separation center position.
The size of the opening of the jet hole is required to be compatible with two working conditions of large flow and small flow. Preferably, the jet aperture diameter is in the range of 0.4mm to 1.0mm. In the low flow condition, the total jet flow quantity of the jet holes is controlled to be 4% -8% of the total flow of the impeller so as to reduce the influence of the jet self-circulation loop on the performance of the centrifugal pump, and in order to form high-speed jet flow, the opening diameters of the first jet holes 11 are required to be smaller. And in the high flow condition, the total jet flow of the jet holes is controlled to be 6% -10% of the total flow of the impeller, and in order to form stable jet flow, the diameter of the opening of the second jet hole 12 is required to be properly increased. In addition, the opening diameters of the first and second orifices 11 and 12 are determined according to the number of circumferential orifice groups. In the embodiment, the number of the blades 4 is six, the number of the circumferential hole groups is twice the number of the blades, and the diameter of the opening of the first jet hole 11 is set to be 0.4mm-0.8mm under the working condition of small flow; in the high flow condition, the aperture diameter of the second jet hole 12 is set to be 0.6mm-1.0mm.
In the centrifugal pump, a self-circulation cavity structure consisting of a liquid storage tank 5 and a through flow pipe 6 is arranged on the outer side of an impeller rim 1, the through flow pipe 6, the liquid storage tank 5 and a jet hole form a high-pressure loop system communicated with the outer side of the impeller rim 1, a liquid inlet of the liquid storage tank 5 is communicated with an impeller outlet runner 7 through the through flow pipe 6, a liquid outlet of the liquid storage tank 5 is communicated with jet holes arranged in an impeller inlet runner 9 through a jet pipe 20, the two jet holes are in a group, the jet directions of a first jet hole 11 and a second jet hole 12 are different, the first jet hole 11 is ejected towards the suction surface of a blade 4, and the second jet hole 12 is ejected towards the front edge and the pressure surface of the blade 4; through controlling the opening and closing of the first jet hole 11 and the second jet hole 12, the communication under different working conditions is realized, the flow of the impeller outlet flow channel 7 flows into the liquid storage tank 5 through the draft tube 6, and then the jet holes at different positions are injected into the impeller inlet flow channel 9, so that the jet flow is applied to the flow field, certain pressure is generated on different surfaces of the impeller according to different flow working conditions, the self-adjustment is realized, and the anti-cavitation performance is improved. In the low flow working condition, because the flow in the impeller inlet flow channel 9 is smaller, the water level monitoring cavity 18 is in a low liquid level state, the water level monitoring floating sliding block 10 descends along with the water level, the connecting rod 9 drives the shielding sliding block 19 to move left, the through hole on the shielding sliding block 19 is communicated with the first jet hole 11, the second jet hole 12 is in a closed state, and high-pressure liquid flow sprayed from the first jet hole 11 to the suction surface of the blade compensates the low pressure of the suction surface of the blade 4, so that the pressure of the low-pressure area is increased to be higher than the vaporization pressure of the liquid, and cavitation of the suction surface of the blade 4 is relieved. Under the working condition of large flow, as the flow in the impeller inlet flow channel 9 is large, the liquid level in the water level monitoring cavity 18 rises, the water level monitoring floating sliding block 10 moves upwards under the buoyancy action, the water level monitoring floating sliding block 10 drives the connecting rod 15 to move upwards, the connecting rod 15 drives the shielding sliding block 19 to move rightwards, the through hole on the shielding sliding block 19 is communicated with the second jet hole 12, the first jet hole 11 is in a closed state, high-pressure fluid sprayed from the second jet hole 12 to the head of the blade 4 and the pressure surface of the blade compensates the low pressure at the position, and cavitation of the pressure surface of the blade is relieved. Therefore, the flow separation area at the front edge of the blade is compensated under different working conditions, the pressure of the pressure surface of the blade can be improved under high flow, and the pressure of the suction surface of the blade can be improved under low flow, so that the cavitation problem of the centrifugal pump caused by the operation of the eccentric working condition is effectively solved, and the operation stability of the centrifugal pump is improved; and the jet structure is not needed to be externally added, the structure is simple, and the implementation is easy.
While the preferred embodiments of the present patent have been described in detail, the present patent is not limited to the above embodiments, and various changes may be made without departing from the spirit of the present patent within the knowledge of those skilled in the art.
Claims (9)
1. The self-circulation jet flow cavitation-resistant structure comprises an impeller and is characterized in that the impeller comprises an impeller rim, a rear cover plate, a front cover plate, blades and a water level monitoring connecting seat, wherein the water level monitoring connecting seat and the front cover plate are respectively arranged at two ends of the impeller rim; a plurality of liquid storage tanks and flow through pipes are arranged on the outer side of the impeller rim, the upper parts of the liquid storage tanks are communicated with the impeller outlet flow channels through the flow through pipes, a plurality of jet holes are formed in the impeller inlet flow channels, and the liquid storage tanks are communicated with the jet holes through the jet pipes; the two jet holes are a group, namely a first jet hole and a second jet hole in sequence according to the flow direction of liquid flow, the axial distribution areas of the first jet hole and the second jet hole in the same group are positioned near the front edge of the blade, the circumferential distribution of the first jet hole and the second jet hole is arranged according to the jet direction, wherein the first jet hole is ejected towards the suction surface of the blade, and the second jet hole is ejected towards the front edge of the blade and the pressure surface; the liquid storage tank is provided with a shielding slide block in a sliding manner, a switch of the first jet hole and the second jet hole is controlled by the shielding slide block, a through hole corresponding to the jet hole is formed in the shielding slide block, a water level monitoring cavity is formed in the water level monitoring connecting seat, a plurality of water level monitoring floating slide blocks are slidably arranged in the water level monitoring cavity, the water level monitoring floating slide blocks are connected with the shielding slide blocks through connecting rods, the water level monitoring floating slide blocks keep a low liquid level state when the small flow working condition is met, the shielding slide blocks enable the first jet hole to be opened, the second jet hole is closed, the water level monitoring floating slide blocks keep a high liquid level state when the large flow working condition is met, and the water level monitoring floating slide blocks drive the shielding slide blocks to move, so that the first jet hole is closed, and the second jet hole is opened.
2. A self-circulating jet cavitation prevention structure according to claim 1, wherein the jet holes are arranged in sequence along the axial direction, the second jet holes are positioned outside the first jet holes, the axial positions of all the first jet holes are the same in different jet hole groups, the axial positions of all the second jet holes are the same, each group of jet holes is independently arranged, and the liquid storage tanks above the different jet hole groups are not communicated with each other.
3. The self-circulation jet anti-cavitation structure of claim 2, wherein the jet hole groups are uniformly distributed in the circumferential direction, and the number of the hole groups is an integer multiple of the number of blades.
4. A self-circulating jet cavitation prevention structure according to claim 3, wherein the number of vanes is six and the number of jet hole sets is twelve.
5. The self-circulation jet anti-cavitation structure according to claim 1, wherein a pump shaft mounting hole is formed in the middle of the hub, a plurality of through holes connected with the through flow pipes are formed in the front cover plate, and the through holes are uniformly distributed in the circumference.
6. The self-circulation jet anti-cavitation structure according to claim 3, wherein a plurality of water level monitoring cavities are formed in the water level monitoring connecting seat, and the number of the water level monitoring cavities is corresponding to that of the liquid storage tanks; the outside of water level monitoring connecting seat is provided with the flange, and the floating slider of water level monitoring slides and sets up in the water level monitoring cavity, and the spacing groove has been seted up to one side of water level monitoring cavity, and the spacing groove is articulated with the one end of connecting rod is worn out to one side of the floating slider of water level monitoring, and the other end of connecting rod is articulated with shielding the slider.
7. A self-circulating jet anti-cavitation structure according to claim 6, wherein the jet aperture diameter is in the range 0.4mm-1.0mm; the total jet flow of the jet holes is controlled to be 4% -8% of the total flow of the impeller under the working condition of small flow, and is controlled to be 6% -10% of the total flow of the impeller under the working condition of large flow.
8. A self-circulating jet cavitation resistant structure as claimed in claim 7, wherein the aperture diameter of the first jet aperture is set to 0.4mm-0.8mm; the aperture diameter of the second jet hole is set to be 0.6mm-1.0mm.
9. A centrifugal pump with an anti-cavitation structure, characterized in that a self-circulation jet anti-cavitation structure according to any one of claims 1-8 is provided in an impeller of the centrifugal pump.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111608524.5A CN115247657B (en) | 2021-12-27 | 2021-12-27 | Self-circulation jet anti-cavitation structure and centrifugal pump with same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111608524.5A CN115247657B (en) | 2021-12-27 | 2021-12-27 | Self-circulation jet anti-cavitation structure and centrifugal pump with same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115247657A CN115247657A (en) | 2022-10-28 |
| CN115247657B true CN115247657B (en) | 2023-05-09 |
Family
ID=83698158
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111608524.5A Active CN115247657B (en) | 2021-12-27 | 2021-12-27 | Self-circulation jet anti-cavitation structure and centrifugal pump with same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115247657B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116221131B (en) * | 2023-04-10 | 2024-03-05 | 台州科技职业学院 | Adjusting device for improving cavitation resistance of water pump and control method |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61145399A (en) * | 1984-12-19 | 1986-07-03 | Hitachi Ltd | Pump |
| CN105650025A (en) * | 2016-01-08 | 2016-06-08 | 兰州理工大学 | Centrifugal pump impeller |
| CN110410369B (en) * | 2019-08-13 | 2024-04-05 | 浙江理工大学 | Cavitation-preventing double-suction pump impeller device with adjustable circumferential angle and method |
| CN112412885B (en) * | 2020-05-09 | 2021-09-07 | 北京理工大学 | Adjustable self-circulation air injection stability expansion structure and centrifugal compressor with stability expansion structure |
| CN111828388A (en) * | 2020-07-22 | 2020-10-27 | 天津理工大学 | Self-circulation anti-cavitation casing suitable for centrifugal/mixed flow type water pump |
-
2021
- 2021-12-27 CN CN202111608524.5A patent/CN115247657B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN115247657A (en) | 2022-10-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115247657B (en) | Self-circulation jet anti-cavitation structure and centrifugal pump with same | |
| JP3872966B2 (en) | Axial fluid machine | |
| CN115143120A (en) | A anti-overflow water structure for self priming pump | |
| CN114033701A (en) | Centrifugal pump structure with high cavitation resistance and low amplitude vibration | |
| CN217029318U (en) | Centrifugal pump | |
| CN112648230A (en) | High-efficient anti cavitation centrifugal pump impeller | |
| CN217950897U (en) | Blowing-sucking separation synthetic jet actuator and ring volume control device suitable for wing | |
| CN216589307U (en) | Anti-cavitation self-circulation casing of axial-flow water pump | |
| CN112628192B (en) | Blade structure for inhibiting axial flow pump blade tip leakage vortex | |
| CN210919596U (en) | Combined steam ejector with water drainage function | |
| CN211449782U (en) | Submerged relief valve based on water conservancy relief | |
| CN109882444B (en) | Mixed flow pump impeller with stepped rectifying device in flow channel | |
| CN207598589U (en) | Inhibit the centrifugal pump device of impeller blade cavitation | |
| CN117627954A (en) | Impeller capable of effectively improving cavitation resistance and high-speed centrifugal pump structure | |
| CN111336131A (en) | Axial force optimization design method for canned motor pump | |
| CN110966441A (en) | Submerged relief valve based on water conservancy relief | |
| EP3394423B1 (en) | Runner for a hydraulic turbine or pump and method of operating such a runner | |
| CN103850947A (en) | Anti-cavitation vane pump | |
| CN211144905U (en) | Water pump runner structure | |
| CN215719575U (en) | Water pump for conveying bilge oil sewage in diving chamber | |
| CN217354888U (en) | Blade and fan | |
| CN218913184U (en) | Water pump, flushing system using same and toilet | |
| CN220015502U (en) | Noise-reducing drainage and circulation integrated pump and washing machine | |
| CN212129071U (en) | Submerged relief valve body | |
| CN114135523B (en) | Filter mechanism arranged at front end of submersible pump |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |