Centrifugal pump capable of being used in total lift and centrifugal pump system

Abstract

The utility model discloses a centrifugal pump capable of being used in a full-lift mode and a centrifugal pump system, relates to the technical field of centrifugal pumps, and is mainly used for solving the problem that an existing centrifugal pump can only meet the high-lift using working condition or the low-lift using working condition. Six long blades and six short blades are arranged in a closed impeller of the centrifugal pump at equal intervals in a staggered mode. The centrifugal pump system comprises a first centrifugal pump and a second centrifugal pump, a water inlet pipe and a water outlet pipe are connected to the first centrifugal pump, the second centrifugal pump communicates with the water inlet pipe through a water inlet branch pipe, and a three-way control valve is arranged on the water outlet pipe and communicates with the second centrifugal pump through a communicating branch pipe. A water outlet pipe on the output side of the three-way control valve communicates with the second centrifugal pump through a water outlet branch pipe. According to the centrifugal pump and the centrifugal pump system capable of being used in the total lift, the centrifugal pump can meet the total lift use working condition at the same time, the system can provide larger lift, and the use requirements of low lift and large flow can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of servo valves, in particular to a centrifugal pump capable of being used at full head and a centrifugal pump system. Background Art

[0002] Centrifugal pumps are the most commonly used liquid transport power machinery today due to their simple and durable structure, reliable operation, high efficiency, large flow rate, and low cost. Due to their operating principle, centrifugal pumps also have corresponding centrifugal pump characteristic curves. The calibration parameters of a centrifugal pump are the flow rate and head parameters corresponding to the centrifugal pump's highest efficiency point. In actual use, the centrifugal pump's operating parameters do not deviate too much from the calibration parameters and are within a reasonable operating range.

[0003] Centrifugal pumps are currently widely used in real-life production applications. Their high flow rates and high efficiency make them practical for a variety of real-life production applications. However, the maximum efficiency of conventional centrifugal pumps is only achieved within the limits of the rated head range. If the head rises above the upper limit of this range, the head will not rise further. If the head falls below the lower limit of this range, although the flow rate will increase, the current will rise even more. In this case, the effective power of the motor cannot be sustained, resulting in severe overload and even burnout.

[0004] This results in the existing centrifugal pumps being able to only meet high-head or low-head operating conditions - centrifugal pumps suitable for high-head will be overloaded when used in the low-head stage; centrifugal pumps suitable for low-head have a low head upper limit and cannot reach the high-head stage.

[0005] At the same time, the existing horizontal centrifugal pumps have high efficiency and large flow in the medium and low head stages, but the efficiency decreases in the high head area; and the existing horizontal multi-stage centrifugal pumps have high efficiency in the medium and high head stages, but cannot show the advantage of large flow in the low head area. Utility Model Content

[0006] The purpose of the utility model is to provide a centrifugal pump that can be used at full head, which can simultaneously meet high-head use conditions and low-head use conditions and has high efficiency.

[0007] Another object of the present invention is to provide a centrifugal pump system using the above centrifugal pump, which can provide a larger head and can meet the use requirements of low head and large flow.

[0008] The utility model solves the previous technical problem through a technical solution: a centrifugal pump and a centrifugal pump system capable of full head use, comprising a volute, a closed impeller and a drive motor, the volute being provided with a volute water outlet pipe and a volute water inlet, the closed impeller being provided with an impeller water inlet, a motor shaft mounting opening being coaxially provided on the inner side of the impeller water inlet, six long blades and six short blades being rotationally symmetrically arranged around its axis being provided in the closed impeller, the long blades and the short blades being equidistantly staggered and arranged, and the long blades and the short blades both being arc-shaped and extending from the edge of the closed impeller toward its axis.

[0009] As a further improvement of the present invention, the inner diameter of the volute is 174 mm, the diameter of the volute water inlet is 52 mm, the length of the volute water outlet pipe is 90 mm, the diameter of its inlet end is 25 mm, and the diameter of the water outlet end is 40 mm.

[0010] As a further improvement of the present invention, the diameter of the closed impeller is 173 mm, the diameter of the impeller water inlet is 51 mm, the adjacent long blades and short blades form an impeller water outlet channel with a width of 7 mm and connected to the inner cavity of the volute, and the diameter of the motor shaft mounting port is 10 mm.

[0011] As a further improvement of the present invention, the volute water outlet pipe is tangentially arranged on the edge of the volute along the outer edge of the volute, the volute water inlet is arranged at the axis center of one side wall of the volute, and the closed impeller is coaxially arranged with the volute and rotatably installed inside the volute.

[0012] As a further improvement of the present invention, the impeller water inlet is arranged at the axis center of the side wall of the closed impeller close to the volute water inlet.

[0013] As a further improvement of the present invention, the drive motor is arranged on one side of the volute, and the output shaft of the drive motor passes through the side wall of the volute and is fixedly connected to the motor shaft mounting opening.

[0014] The technical solution of the utility model to solve the second technical problem is: a centrifugal pump system using the above centrifugal pump, comprising a first centrifugal pump and a second centrifugal pump arranged coaxially and connected to each other, wherein the volute water inlets of the first centrifugal pump and the second centrifugal pump are respectively located on opposite sides of the first centrifugal pump and the second centrifugal pump, and the closed impellers of the first centrifugal pump and the second centrifugal pump are arranged in opposite directions;

[0015] The volute water inlet of the first centrifugal pump is connected to an inlet pipe, the volute water inlet of the second centrifugal pump is connected to the water inlet pipe through an inlet branch pipe, and an inlet branch switch valve is installed on the water inlet branch pipe; the volute water outlet pipe of the first centrifugal pump is connected to an outlet pipe, and the outlet pipe is provided with a three-way control valve, and the three-way control valve is also connected to the volute water inlet of the second centrifugal pump through a connecting branch pipe, and the outlet pipe on the output side of the three-way control valve is connected to the volute water outlet pipe of the second centrifugal pump through the outlet branch pipe.

[0016] As a further improvement of the present invention, there is only one driving motor.

[0017] As a further improvement of the present invention, the drive motor is arranged on a side of the first centrifugal pump away from the second centrifugal pump, and the output shaft of the drive motor passes through the first centrifugal pump and extends into the second centrifugal pump, and the closed impellers in the first centrifugal pump and the second centrifugal pump are both fixedly connected to the output shaft of the drive motor through the motor shaft mounting port.

[0018] As a further improvement of the present invention, a main switch valve is provided on the input end of the water inlet pipe, and the water inlet branch pipe is arranged on the water inlet pipe on the output side of the main switch valve.

[0019] Beneficial effects

[0020] Compared with the prior art, the centrifugal pump and centrifugal pump system of the utility model that can be used at full head have the following advantages:

[0021] 1. Compared with the existing centrifugal pump, the centrifugal pump in this scheme adopts a structure in which six long blades and six short blades are arranged in an equidistant and staggered manner, and both the long blades and the short blades are extended in an arc direction from the edge of the closed impeller toward its axis. By superimposing the pressure of the six long blades and the six short blades, the head range of the centrifugal pump can be effectively improved, thereby being able to meet both high-head and low-head operating conditions at the same time, and with high efficiency.

[0022] 2. Compared with the existing centrifugal pump, the inner diameter of the volute of this centrifugal pump is 174mm, the diameter of the volute water inlet is 52mm, the length of the volute water outlet pipe is 90mm, the diameter of its inlet end is 25mm, and the diameter of the water outlet end is 40mm; at the same time, the diameter of the closed impeller is 173mm, the diameter of the impeller water inlet is 51mm, the width of the impeller water outlet channel is 7mm, and the diameter of the motor shaft mounting port is 10mm; through the parameter design of the centrifugal pump in this scheme, excessive flow suction can be effectively avoided, thereby reducing power consumption, and thus the power consumed by the centrifugal pump is kept within the effective range of the motor during the entire full-stroke stage.

[0023] 3. In this centrifugal pump system, the series / parallel switching of the first and second centrifugal pumps can be achieved by opening / closing the water inlet branch switch valve and switching the three-way control valve. When the system is used in the low-lift stage, the first and second centrifugal pumps are connected in parallel, and the flow rate reaches the sum of the two pumps, while the motor power remains unchanged. When the system is used in the high-lift stage, the first and second centrifugal pumps are connected in series, and the head can reach the sum of the first and second centrifugal pumps, thereby providing a higher head limit. As a result, the system can provide a greater head and meet the needs of low-lift and high-flow applications.

[0024] The present invention will become more clear through the following description in conjunction with the accompanying drawings, which are used to explain embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a front view of the centrifugal pump of the present utility model;

[0027] Figure 2 It is a front view of the volute of the present invention;

[0028] Figure 3 This is a front view of the closed impeller of the utility model;

[0029] Figure 4 This is a rear view of the closed impeller of the present invention;

[0030] Figure 5 It is a cross-sectional view of the closed impeller of the utility model;

[0031] Figure 6 A three-dimensional diagram of the closed impeller of the present invention;

[0032] Figure 7 This is a structural diagram of the centrifugal pump system of the present utility model.

[0033] Among them: 1-volute; 11-volute water inlet; 12-volute water outlet pipe; 2-closed impeller; 21-long blade; 22-short blade; 23-impeller water inlet; 24-impeller water outlet channel; 25-motor shaft mounting port; 3-drive motor; 4-water inlet pipe; 41-water inlet branch pipe; 5-main switch valve; 51-water inlet branch switch valve; 6-water outlet pipe; 61-water outlet branch pipe; 7-three-way control valve; 71-connecting branch pipe; 8-first centrifugal pump; 9-second centrifugal pump. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings. It is apparent that the embodiments described herein are merely a portion of the embodiments of the present invention, and not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0035] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; of course, they can also refer to mechanical connections or electrical connections; in addition, they can also refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0036] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0037] Example

[0038] The specific implementation of the utility model is as follows Figure 1-6 As shown, a centrifugal pump capable of full-lift operation comprises a volute 1, a closed impeller 2, and a drive motor 3. The volute 1 is provided with a volute outlet pipe 12 and a volute inlet 11; the closed impeller 2 is provided with an impeller inlet 23, and a motor shaft mounting opening 25 is coaxially disposed inside the impeller inlet 23. In this embodiment, the volute outlet pipe 12 is disposed tangentially along the outer edge of the volute 1, and the volute inlet 11 is disposed at the axis center of a sidewall of the volute 1. The closed impeller 2 is coaxially disposed with the volute 1 and rotatably mounted within the volute 1. Furthermore, the impeller inlet 23 is disposed at the axis center of the sidewall of the closed impeller 2 on the side closest to the volute inlet 11. To enable the drive motor 3 to drive the closed impeller 2 axially, the drive motor 3 is disposed on one side of the volute 1, and the output shaft of the drive motor 3 passes through the sidewall of the volute 1 and is fixedly connected to the motor shaft mounting opening 25.

[0039] In order to achieve the full head use of the centrifugal pump, the closed impeller 2 is provided with six long blades 21 and six short blades 22 that are rotationally symmetrically arranged around its axis. Specifically: the long blades 21 and the short blades 22 are staggered at equal distances, and the long blades 21 and the short blades 22 are both extended in an arc direction from the edge of the closed impeller 2 toward its axis. Compared with the existing centrifugal pumps, the centrifugal pump in this scheme adopts a structure in which six long blades 21 and six short blades 22 are staggered at equal distances, and the long blades 21 and the short blades 22 are both extended in an arc direction from the edge of the closed impeller 2 toward its axis. By superimposing the pressure of the six long blades 21 and the six short blades 22, the head range of the centrifugal pump can be effectively improved, thereby being able to meet both high-head and low-head operating conditions at the same time, and with high efficiency.

[0040] In this embodiment, the inner diameter of the volute 1 is 174 mm, the diameter of the volute water inlet 11 is 52 mm, the length of the volute water outlet pipe 12 is 90 mm, and the diameter of the inlet end of the volute water outlet pipe 12 is 25 mm, and the diameter of the outlet end is 40 mm. Corresponding to the size parameters of the volute 1, the diameter of the closed impeller 2 is 173 mm, the diameter of the impeller water inlet 23 is 51 mm, the adjacent long blades 21 and short blades 22 form an impeller water outlet channel 24 with a width of 7 mm and connected to the inner cavity of the volute 1, and the diameter of the motor shaft mounting port 25 is 10 mm. By designing the parameters of the centrifugal pump in this solution, excessive flow suction can be effectively avoided, thereby reducing power consumption, and thus ensuring that the power consumed by the centrifugal pump remains within the effective range of the motor during the entire full-stroke stage.

[0041] It should be noted that, in actual use, in order to further improve the wide range of operating conditions of the product, the volute 1 can be equipped with more than two stages of closed impellers 2 to adapt to applications with higher lift.

[0042] like Figure 7 As shown, this embodiment also discloses a centrifugal pump system using the above-mentioned centrifugal pump, comprising a first centrifugal pump 8 and a second centrifugal pump 9 that are coaxially arranged and interconnected. The volute water inlets 11 of the first centrifugal pump 8 and the second centrifugal pump 9 are located on opposite sides of the first centrifugal pump 8 and the second centrifugal pump 9, respectively. In addition, the closed impellers 2 of the first centrifugal pump 8 and the second centrifugal pump 9 are arranged in opposite directions, that is, of the two closed impellers 2 of the first centrifugal pump 8 and the second centrifugal pump 9, one is a positive impeller and the other is a negative impeller. The combination of positive and negative impellers solves the balance of axial forces, can offset the axial forces, make the structure simpler and more reliable, avoid excessive wear of the motor shaft, and evenly apply radial forces on both sides of the motor shaft, so that the operation is stable and the service life of the water pump is greatly improved.

[0043] In this centrifugal pump system, the connection relationship between the first centrifugal pump 8 and the second centrifugal pump 9 is as follows: the volute water inlet 11 of the first centrifugal pump 8 is connected to the water inlet pipe 4, and the volute water inlet 11 of the second centrifugal pump 9 is connected to the water inlet pipe 4 via a water inlet branch pipe 41, and the water inlet branch pipe switching valve 51 is installed on the water inlet branch pipe 41. The volute water outlet pipe 12 of the first centrifugal pump 8 is connected to the water outlet pipe 6, and the water outlet pipe 6 is provided with a three-way control valve 7. The three-way control valve 7 is also connected to the volute water inlet 11 of the second centrifugal pump 9 via a connecting branch pipe 71. The water outlet pipe 6 on the output side of the three-way control valve 7 is connected to the volute water outlet pipe 12 of the second centrifugal pump 9 via a water outlet branch pipe 61.

[0044] In this centrifugal pump system, the series / parallel switching of the first centrifugal pump 8 and the second centrifugal pump 9 can be achieved by opening / closing the water inlet branch switch valve 51 and switching the three-way control valve 7. Specifically, when the system is used in the low-lift stage, the water inlet branch switch valve 51 is opened, the three-way control valve 7 keeps the outlet pipe 6 on its inlet and outlet sides connected, and the connecting branch 71 is closed. At this time, the first centrifugal pump 8 and the second centrifugal pump 9 in the entire system are in a parallel state, the flow rate reaches the sum of the two pumps, and the motor power remains unchanged. When the system is used in the high-lift stage, the water inlet branch switch valve 51 is closed, the three-way control valve 7 blocks the outlet pipe 6 on its inlet and outlet sides, and opens the connecting branch 71. At this time, the first centrifugal pump 8 and the second centrifugal pump 9 in the entire system are in a series state, and the head can reach the sum of the first centrifugal pump 8 and the second centrifugal pump 9, thereby providing a larger head limit. As a result, the system can provide a larger head and can meet the use requirements of low head and high flow.

[0045] In this system, there is only one drive motor 3. The drive motor 3 is arranged on the side of the first centrifugal pump 8 facing away from the second centrifugal pump 9, and the output shaft of the drive motor 3 passes through the first centrifugal pump 8 and extends into the second centrifugal pump 9. The closed impellers 2 in the first centrifugal pump 8 and the second centrifugal pump 9 are both fixedly connected to the output shaft of the drive motor 3 through the motor shaft mounting opening 25. In this embodiment, a mounting pipe is provided at the volute water inlet 11 of the first centrifugal pump 8 and the second centrifugal pump 9, and the first centrifugal pump 8 and the second centrifugal pump 9 are respectively connected to the water inlet pipe 4 and the water inlet branch pipe 41 through the mounting pipe. In addition, the drive motor 3 arranged on the side of the first centrifugal pump 8 facing away from the second centrifugal pump 9 is also mounted on the mounting pipe of the first centrifugal pump 8. Specifically, the output end of the drive motor 3 is sealedly connected to the end of the mounting pipe away from the first centrifugal pump 8, and the output shaft of the drive motor 3 extends axially through the first centrifugal pump 8 along the mounting pipe into the second centrifugal pump 9. Furthermore, when the output shaft passes through the junction of the first centrifugal pump 8 and the second centrifugal pump 9, the output shaft and the junction will maintain a rotational sealing fit, thereby preventing the inner cavity of the first centrifugal pump 8 and the inner cavity of the second centrifugal pump 9 from directly communicating with each other.

[0046] In addition, in order to control the water inlet of the entire system, a main switch valve 5 is provided on the input end of the water inlet pipe 4 , and a water inlet branch pipe 41 is provided on the water inlet pipe 4 on the output side of the main switch valve 5 .

[0047] For the specific use of the system, a 7.5-kilowatt three-phase motor is used as the drive motor 3 as an example. The diameter of the inlet end of the volute outlet pipe 12 of the first centrifugal pump 8 in the system is 25 mm, the diameter of the outlet end is 40 mm, the length is 90 mm, and the diameter of the volute water inlet 11 is 52 mm; the closed impeller 2 is a reverse flow channel with a diameter of 173 mm, the diameter of the impeller water inlet 23 is 51 mm, the diameter of the motor shaft mounting port 25 is 10 mm, and the width of the outlet flow channel is 7 mm.

[0048] The diameter of the inlet end of the volute outlet pipe 12 of the second centrifugal pump 9 in the system is 25 mm, the diameter of the outlet end is 40 mm, the length is 90 mm, and the diameter of the volute water inlet 11 is 52 mm; the closed impeller 2 is a positive flow channel with a diameter of 173 mm, the diameter of the impeller water inlet 23 is 51 mm, the diameter of the motor shaft mounting port 25 is 10 mm, and the width of the outlet flow channel is 7 mm.

[0049] The system has been tested for this parameter, and the test parameters for the low-lift section are: 5 meters 56 cubic meters, current 12.6 amps; 35 meters 50 cubic meters, current 14.6 amps; 40 meters 40 cubic meters, current 13.5 amps. The high-lift section is: 68 meters 25 cubic meters, current 14.3 amps, 78 meters 20 cubic meters, current 12.6 amps.

[0050] Existing centrifugal pump impeller designs only consider normal operation within the rated range, without considering operating characteristics within the motor's effective power range. This centrifugal pump system combines the low-head, high-flow characteristics of a horizontal centrifugal pump with the high-head characteristics of a vertical multi-stage centrifugal pump. With an optimized full-head centrifugal impeller design, this centrifugal pump system will not overload the motor power regardless of the operating range.

[0051] The present invention is described above in conjunction with the best embodiments, but the present invention is not limited to the embodiments disclosed above, but should cover various modifications and equivalent combinations based on the essence of the present invention.

Claims

1. A centrifugal pump capable of full head operation, comprising a volute (1), a closed impeller (2) and a drive motor (3), wherein the volute (1) is provided with a volute water outlet pipe (12) and a volute water inlet (11), the closed impeller (2) is provided with an impeller water inlet (23), and a motor shaft mounting opening (25) is coaxially provided on the inner side of the impeller water inlet (23), characterized in that: The closed impeller (2) is provided with six long blades (21) and six short blades (22) which are arranged rotationally symmetrically around its axis. The long blades (21) and the short blades (22) are arranged in an equidistant and staggered manner, and the long blades (21) and the short blades (22) are both extended in an arc direction from the edge of the closed impeller (2) toward its axis.

2. The centrifugal pump capable of full head use according to claim 1, characterized in that: The inner diameter of the volute (1) is 174 mm, the diameter of the volute water inlet (11) is 52 mm, the length of the volute water outlet pipe (12) is 90 mm, the diameter of the inlet end is 25 mm, and the diameter of the water outlet end is 40 mm.

3. The centrifugal pump capable of full head use according to claim 2, characterized in that: The diameter of the closed impeller (2) is 173 mm, the diameter of the impeller water inlet (23) is 51 mm, the adjacent long blades (21) and short blades (22) form an impeller water outlet channel (24) with a width of 7 mm and connected to the inner cavity of the volute (1), and the diameter of the motor shaft mounting port (25) is 10 mm.

4. The centrifugal pump capable of full head use according to claim 3, characterized in that: The volute water outlet pipe (12) is tangentially arranged on the edge of the volute (1) along the outer edge of the volute (1); the volute water inlet (11) is arranged at the axis center of one side wall of the volute (1); and the closed impeller (2) is coaxially arranged with the volute (1) and rotatably installed inside the volute (1).

5. The centrifugal pump capable of full head use according to claim 4, characterized in that: The impeller water inlet (23) is arranged at the axis center of the side wall of the closed impeller (2) close to the volute water inlet (11).

6. The centrifugal pump capable of full head use according to claim 5, characterized in that: The drive motor (3) is arranged on one side of the volute (1), and the output shaft of the drive motor (3) passes through the side wall of the volute (1) and is fixedly connected to the motor shaft mounting opening (25).

7. A centrifugal pump system using the centrifugal pump according to any one of claims 1 to 6, characterized in that: The invention comprises a first centrifugal pump (8) and a second centrifugal pump (9) which are coaxially arranged and connected to each other, wherein the volute water inlets (11) of the first centrifugal pump (8) and the second centrifugal pump (9) are respectively located on opposite sides of the first centrifugal pump (8) and the second centrifugal pump (9), and the closed impellers (2) of the first centrifugal pump (8) and the second centrifugal pump (9) are arranged in opposite directions; The volute water inlet (11) of the first centrifugal pump (8) is connected to a water inlet pipe (4), and the volute water inlet (11) of the second centrifugal pump (9) is connected to the water inlet pipe (4) through a water inlet branch pipe (41), and a water inlet branch pipe switch valve (51) is installed on the water inlet branch pipe (41); the volute water outlet pipe (12) of the first centrifugal pump (8) is connected to a water outlet pipe (6), and a three-way control valve (7) is provided on the water outlet pipe (6). The three-way control valve (7) is also connected to the volute water inlet (11) of the second centrifugal pump (9) through a connecting branch pipe (71), and the water outlet pipe (6) on the output side of the three-way control valve (7) is connected to the volute water outlet pipe (12) of the second centrifugal pump (9) through a water outlet branch pipe (61).

8. The centrifugal pump system according to claim 7, characterized in that There is only one driving motor (3).

9. The centrifugal pump system according to claim 8, characterized in that The drive motor (3) is arranged on a side of the first centrifugal pump (8) facing away from the second centrifugal pump (9), and the output shaft of the drive motor (3) passes through the first centrifugal pump (8) and extends into the second centrifugal pump (9), and the closed impellers (2) in the first centrifugal pump (8) and the second centrifugal pump (9) are fixedly connected to the output shaft of the drive motor (3) through the motor shaft mounting opening (25).

10. The centrifugal pump system according to claim 7, wherein: A main switch valve (5) is provided on the input end of the water inlet pipe (4), and the water inlet branch pipe (41) is provided on the water inlet pipe (4) on the output side of the main switch valve (5).

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