A high-pressure constant-pressure centrifugal pump and an intelligent energy-saving control system

Abstract

The application discloses a high-pressure constant-pressure centrifugal pump and an intelligent energy-saving control system. The centrifugal pump comprises a pump body and an impeller. The impeller comprises a front cover plate, a rear cover plate and rear-bent blades arranged inside the front cover plate and the rear cover plate. The impeller further comprises short blades fixed to the outer edges of the front cover plate and the rear cover plate and arranged uniformly in the circumferential direction of the impeller. The short blades are straight blades extending radially outwardly from the impeller. The end of each rear-bent blade is connected with a short blade, and a plurality of short blades are arranged between two adjacent rear-bent blades. The internal flow channel section of the volute of the pump body is a peanut shell type section comprising two parallel circular arcs. The centrifugal pump can improve the lift and maintain constant pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of centrifugal pumps, in particular to a high-pressure constant-pressure centrifugal pump and an intelligent energy-saving control system. BACKGROUND

[0002] A centrifugal pump is a kind of pump that uses the centrifugal force generated by the rotation of an impeller to work, and is widely used in petrochemical, construction, agriculture and pharmaceutical industries. The traditional centrifugal pump has a simple structure, which is composed of a pump body, an impeller, a pump cover, a shaft and a bearing, as shown in FIG. Figure 1 However, the traditional centrifugal pump has the disadvantages of low efficiency, low lift and low pressure, and cannot meet the application requirements of some special industries, such as the fire-fighting industry. In particular, the fire-fighting pump not only needs to increase the lift but also needs to achieve the purpose of constant pressure. In addition, in some occasions, the centrifugal pump needs to have a higher outlet pressure. At present, the common method to improve the efficiency and lift on the market is to increase the diameter of the impeller, increase the outlet angle of the blade, increase the speed, increase the number of blades, and use a multi-stage pump. Although these methods are simple and effective, in actual application, due to the problems of processing technology and energy consumption, the traditional improvement method often requires more energy consumption and higher manufacturing cost.

[0003] In addition, with the popularization of intelligence and automation, the centrifugal pump control system is used more and more frequently in engineering. In order to maximize the control effect of the system, it is necessary to continuously optimize the centrifugal pump control system in practical application. However, in the current intelligent control system of the centrifugal pump, the monitoring link has a certain lag, and cannot monitor in real time according to the specific operating conditions of the centrifugal pump, so that the centrifugal pump cannot respond to the sudden situation in the running process, and the management personnel need to intervene manually. However, in reality, the management personnel of the centrifugal pump control system do not fully understand the control system, and cannot make very accurate judgments and operations, so as to not only affect the effect of the centrifugal pump control system, but also waste a certain amount of energy. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a high-pressure constant-pressure centrifugal pump and an intelligent energy-saving control system, which improves the structure of the impeller and adaptively improves the structure of the volute of the pump body, so as to increase the pressure, lift and constant pressure. At the same time, in order to better control the operating conditions of the pump to achieve the purpose of energy saving and improve the efficiency, a new intelligent control system is provided.

[0005] The purpose of the present application is achieved by the following technical solutions:

[0006] A high-pressure constant-pressure centrifugal pump, comprising a pump body and an impeller; the impeller comprises a front cover plate, a rear cover plate, and a rear bent blade located inside the front cover plate and the rear cover plate;

[0007] The impeller further comprises short blades fixed at the outer edges of the front cover plate and the rear cover plate and arranged uniformly in the circumferential direction of the impeller; the short blades are straight blades extending radially outwardly, and the end of each rear curved blade is connected with a short blade, and several short blades are arranged between two adjacent rear curved blades.

[0008] The internal flow passage section of the volute of the pump body is a peanut shell type section comprising two parallel circular arcs.

[0009] Further, two short blades are arranged between two adjacent rear curved blades.

[0010] An intelligent energy-saving control system comprising a high-pressure constant-pressure centrifugal pump, further comprising a flow control valve, an electromagnetic flowmeter, a pressure transmitter, a central controller, a cavitation tank and a pressure stabilizing tank.

[0011] The pressure transmitter is located at the inlet and outlet positions of the centrifugal pump, and is used for measuring the inlet pressure and outlet pressure of the centrifugal pump and feeding back the same to the central controller in real time.

[0012] The electromagnetic flowmeter is located at the outlet position of the pressure stabilizing tank, and is used for measuring the outlet flow of the centrifugal pump at constant pressure and feeding back the same to the central controller in real time.

[0013] The flow control valve is located behind the electromagnetic flowmeter, so as to control the outlet flow of the centrifugal pump.

[0014] The central controller is electrically connected with the motor of the centrifugal pump, the flow control valve, the electromagnetic flowmeter and the pressure transmitter, and is used for calculating the lift of the centrifugal pump in real time and calculating the performance characteristic curve of the pump in real time.

[0015] Further, the central controller further performs estimation and prediction according to the set threshold values of lift, flow or efficiency, and adopts a Bayesian regularization BP neural network; when the prediction error of the Bayesian regularization BP neural network is less than the set threshold value, the set lift, flow or efficiency is self-adapted, and the motor speed of the centrifugal pump and the flow control valve are automatically adjusted, so that the centrifugal pump operates at the set working condition.

[0016] Further, the set working condition of the centrifugal pump operation comprises a working condition with the highest efficiency or a working condition with the most energy saving.

[0017] The beneficial effects of the present application are as follows:

[0018] 1. This invention improves the impeller structure of a traditional centrifugal pump by adding radially extending short blades to the end of each rotating blade of a conventional closed impeller. Simultaneously, two radially extending short blades are also placed at the impeller outlet between two adjacent rotating blades. To accommodate the improved impeller, the cross-section of the volute region at the impeller outlet is also modified to a peanut shell shape. This allows the fluid flowing out from one side of the short blades to re-enter the flow channel between the short blades and be repeatedly circulated and pressurized to gain energy, thereby achieving the goal of simultaneously increasing pressure and raising head.

[0019] 2. Because the outlet angle of the short blades of the impeller is vertical, according to the theoretical characteristic curve of pump head and flow rate, it can play a constant pressure role compared with the structure of traditional impellers.

[0020] 3. The intelligent energy-saving control system of the present invention has pressure transmitters installed at the inlet and outlet of the pump to monitor the pump head in real time, and an electromagnetic flowmeter installed at the outlet of the pressure stabilizing tank. The pressure transmitters, electromagnetic flowmeters, flow control valves and motors are connected through a central intelligent controller. The system can obtain the pump performance curve in real time and automatically adjust the motor speed and flow control valve to ensure that the pump always operates in the optimal state. Furthermore, the central controller has a built-in BRBP neural network for adaptive control, thereby achieving the purpose of intelligent control and energy saving. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the cross-section of a traditional centrifugal pump.

[0022] Figure 2 This is a top view of the impeller of a centrifugal pump according to an embodiment of the present invention.

[0023] Figure 3 This is a perspective view of the impeller of a centrifugal pump according to an embodiment of the present invention.

[0024] Figure 4 This is a cross-sectional schematic diagram of a centrifugal pump according to an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the theoretical characteristic curves of the pump's head and flow rate.

[0026] Figure 6 This is a schematic diagram of an intelligent energy-saving control system according to an embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram of the control flow of the central controller in the intelligent control system of the embodiment.

[0028] In the diagram, 1 is the impeller, 2 is the short blade, 3 is the backward-curved blade, 4 is the pump body, 5 is the arc-shaped pressurized pump chamber, 6 is the flow control valve, 7 is the electromagnetic flow meter, 8 is the pressure transmitter, 9 is the central controller, 10 is the cavitation tank, and 11 is the pressure stabilizing tank. DETAILED DESCRIPTION

[0029] The present application will be described in detail below with reference to the drawings and preferred embodiments, the objects and effects of the present application will become more apparent, and it should be understood that the specific embodiments described herein are merely intended to explain the present application and not to limit the present application.

[0030] In the drawings, only components related to the present application are shown, rather than the number, shape and size of components when actually implemented, the shape, number and proportion of each component when actually implemented can be arbitrarily changed, and the layout of the components can be more complex. The structure, proportion, size, etc. shown in the drawings of the specification are only used to cooperate with the content disclosed in the specification for understanding and reading by those skilled in the art, and do not limit the implementation conditions of the present application, so they do not have technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope covered by the disclosed technology.

[0031] As shown in Figure 2 and Figure 3 , it is an impeller 1 of a centrifugal pump, the blades of the impeller include back-curved blades 3 inside the front cover plate and the rear cover plate, and short blades 2 arranged along the circumference of the impeller are arranged at the outer edges of the front cover plate and the rear cover plate. The short blades 2 are straight blades extending radially outward from the impeller. The end of each back-curved blade 3 is connected to a short blade 2, and two short blades 2 are arranged between two adjacent back-curved blades 3.

[0032] As shown in Figure 4 , in order to adapt to the impeller 1, the internal flow passage cross section of the volute is increased by one circular arc face on the basis of the traditional single circular arc face, that is, the internal flow passage cross section of the volute is a peanut shell type cross section containing two parallel circular arcs. When the impeller 1 is working, part of the fluid pressurized by the impeller leaks from one side of the short blade 2, and due to the action of gravity, re-enters the short blade 2 in the circumference of the impeller, and is pressurized again by the impeller 1, thereby realizing repeated circulation of the fluid, so that the fluid obtains more energy, which is beneficial to improve the lift and reduce the occurrence of cavitation, and since the short blades 2 are straight blades extending along the radial direction, the stability of the lift and the flow can be maintained, and the constant pressure effect can be achieved.

[0033] According to the basic equation of the centrifugal pump:

[0034]

[0035] In the formula, H is the theoretical lift, Q is the theoretical flow, v2 is the peripheral velocity of the liquid at the outlet of the impeller, n is the rotational speed of the impeller, β2 is the flow angle, D2 is the outlet diameter, and b2 is the blade outlet width.

[0036] The short blade outlet angle is perpendicular to the vertical state, according to the theoretical characteristic curve of the pump head flow, compared with the traditional impeller structure (β2<90°), not only improves the head, but also plays a constant pressure role. Figure 5

[0037] As shown in Figure 6 The embodiment of the application also provides an intelligent energy-saving control system comprising the above centrifugal pump, including a flow control valve 6, an electromagnetic flowmeter 7, a pressure transmitter 8, a central controller 9, a cavitation tank 10, and a constant pressure tank 11. The pressure transmitter 8 is located at the inlet and outlet positions of the centrifugal pump, used to measure the inlet pressure and outlet pressure of the pump and real-time feedback to the central controller 9. The electromagnetic flowmeter 7 is located at the outlet position of the constant pressure tank 11, used to measure the outlet flow of the pump at constant pressure and real-time feedback to the central controller 9. The flow control valve 6 is located after the electromagnetic flowmeter 7 to facilitate the control of the outlet flow. The central controller 9 is connected to the flow control valve 6, the electromagnetic flowmeter 7, the pressure transmitter 8, and the motor of the pump, and can calculate the performance characteristic curve of the pump in real time (including the flow-head curve, the efficiency-flow characteristic curve, and the shaft power-flow characteristic curve).

[0038] As shown in Figure 6 and Figure 7 The central controller 9 will monitor the performance characteristic curve of the pump in real time, set the threshold of head, flow or efficiency, and use the Bayesian Regularization BP (BRBP) neural network for prediction and prediction. When the BRBP neural network has a prediction error of less than 5%, it can adopt adaptive head, flow or efficiency settings to achieve the purpose of intelligent control.

[0039] The Bayesian Regularization BP neural network is based on the BP neural network, which introduces the Bayesian regularization rule to train the BP neural network, without the need for accurate setting of network parameters, with particularly fast training speed, good generalization performance and far exceeding the BP neural network.

[0040] The central controller 9 automatically adjusts the motor speed and the flow control valve 6 according to the adaptive control of the BRBP neural network to reduce cavitation and maintain high-efficiency operation, so that the centrifugal pump operates in the set working condition, thereby achieving the best state. The central controller 9 can also manually adjust the motor speed and the flow control valve 6 according to the efficiency threshold and the flow threshold to achieve the set working condition, thereby achieving the energy-saving requirement. The BRBP neural network can use the real-time monitored pump performance data as the training set, and verify the real-time prediction results to ensure that the error is always less than 5%.

[0041] ​Those skilled in the art can understand that the above description is only the preferred examples of the present application and is not used to limit the present application, and although the present application is described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for part of the technical features. Any modification, equivalent replacement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high pressure constant pressure centrifugal pump, characterized by, The centrifugal pump comprises a pump body and an impeller (1); the impeller (1) comprises a front cover plate, a rear cover plate, and rear curved blades (3) inside the front cover plate and the rear cover plate; The impeller (1) further comprises short blades (2) fixed at the outer edges of the front cover plate and the rear cover plate and arranged uniformly in the circumferential direction of the impeller (1); the short blades (2) are straight blades extending radially outwardly from the impeller (1), the end of each rear curved blade (3) is connected with one short blade (2), and a plurality of short blades (2) are arranged between two adjacent rear curved blades (3); The internal flow passage section of the volute of the pump body is a peanut shell type section comprising two parallel circular arcs; The short blades extend outwardly beyond the outer edges of the front cover plate and the rear cover plate and into the peanut shell type section of the volute.

2. The high-pressure constant- pressure centrifugal pump according to claim 1, characterized in that, Two short blades (2) are arranged between two adjacent rear curved blades (3).

3. An intelligent energy saving control system comprising the high pressure constant pressure centrifugal pump of claim 1, wherein, The centrifugal pump further comprises a flow control valve (6), an electromagnetic flowmeter (7), a pressure transmitter (8), a central controller (9), a cavitation tank (10), and a pressure stabilizing tank (11); The pressure transmitter (8) is located at the inlet and outlet positions of the centrifugal pump and is used to measure the inlet pressure and outlet pressure of the centrifugal pump and to feed back the measured values to the central controller (9) in real time; The electromagnetic flowmeter (7) is located at the outlet position of the pressure stabilizing tank (11) and is used to measure the outlet flow of the centrifugal pump under constant pressure and to feed back the measured values to the central controller (9) in real time; The flow control valve (6) is located behind the electromagnetic flowmeter (7) and is used to control the outlet flow of the centrifugal pump; The central controller (9) is electrically connected with the motor of the centrifugal pump, the flow control valve (6), the electromagnetic flowmeter (7), and the pressure transmitter (8) and is used to calculate the lift of the centrifugal pump in real time and to calculate the performance characteristic curve of the pump in real time.

4. The intelligent energy saving control system of claim 3, wherein, The central controller (9) further performs prediction and estimation according to the set threshold values of lift, flow, or efficiency and by using a Bayesian regularized BP neural network; when the prediction error of the Bayesian regularized BP neural network is less than the set threshold value, the set values of lift, flow, or efficiency are self-adapted, the motor speed of the centrifugal pump and the flow control valve (6) are automatically adjusted, and the centrifugal pump is operated under the set working condition.

5. The intelligent energy saving control system of claim 3, wherein, The set working condition of the centrifugal pump operation includes the working condition with the highest efficiency or the most energy-saving working condition.

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