Method and system for measuring and calculating pump efficiency of agricultural irrigation electric centrifugal pump

Abstract

The invention discloses a method and system for measuring the efficiency of an agricultural irrigation electric centrifugal pump, and relates to the technical field of agricultural centrifugal pump energy-saving operation management.The method comprises the steps that a first function relation and a second function relation matched with a to-be-measured centrifugal pump are obtained from a database; the first function relational expression is used for describing a mapping relation between the pump lift and the pump shaft power; the second function relational expression is used for describing a mapping relation between the pump lift and the pump efficiency; the actual pump lift of the centrifugal pump to be measured during operation is substituted into the first function relation and the second function relation, and a corresponding pump shaft power reference value and a corresponding pump efficiency reference value are obtained through calculation; and based on the pump shaft power reference value, the pump efficiency reference value and the actual pump shaft power of the to-be-tested centrifugal pump during operation, the actual pump efficiency of the to-be-tested centrifugal pump is obtained through calculation. According to the method, the actual pump efficiency can be calculated without a pump flow monitoring device, and the problem that the pump efficiency cannot be monitored due to high cost of small and medium-sized agricultural irrigation users is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy-saving operation management of agricultural centrifugal pumps, and particularly relates to a pump efficiency calculation method and system for an agricultural irrigation electric centrifugal pump. BACKGROUND

[0002] The agricultural irrigation electric centrifugal pump is a common and important fluid conveying device, and is one of important energy consumption devices for agricultural production. Real-time grasping of the running efficiency of the centrifugal pump and timely discovery of abnormal changes in the efficiency are important contents of energy-saving and consumption-reducing management of agriculture and enterprises.

[0003] Due to the fact that the actual situation on site is not completely consistent with the expected situation of the centrifugal pump in design and selection, the efficiency of the centrifugal pump in actual operation may greatly deviate from the high-efficiency operation zone of the original design. The real-time monitoring device for the pump efficiency of the centrifugal pump can be installed to real-time grasp the running efficiency of the pump, and the pump in the low-efficiency operation zone can be timely adjusted according to the running efficiency, so that the energy consumption of enterprises in the fluid conveying link can be effectively reduced.

[0004] In the conventional pump efficiency calculation method and measurement system, a pump flow measurement device with high price needs to be installed, but the installation and operation environment is strictly required, and professional calibration needs to be performed regularly, so the maintenance cost is high. Therefore, considering the cost factor, most of the small and medium-sized enterprise users cannot install the pump flow measurement device, and cannot real-time grasp whether the centrifugal pump is running in the designed high-efficiency zone. According to experience, many water pumps in such occasions are running in the non-high-efficiency zone, and even work in the low-efficiency state for a long time without knowing, which causes considerable energy loss in the agricultural field. SUMMARY

[0005] The present application solves the technical problem that small and medium-sized agricultural irrigation users cannot perform pump efficiency monitoring due to high cost, and aims to provide a pump efficiency measurement method and system for agricultural irrigation electric centrifugal pumps, which solves the above problems.

[0006] The present application is implemented by the following technical scheme:

[0007] In a first aspect, the present application provides a pump efficiency measurement method for agricultural irrigation electric centrifugal pumps, comprising:

[0008] obtaining a first function relationship and a second function relationship matched with the centrifugal pump to be measured from a database; the first function relationship is used to describe the mapping relationship between the pump head and the pump shaft power; and the second function relationship is used to describe the mapping relationship between the pump head and the pump efficiency;

[0009] obtaining the actual pump head of the centrifugal pump to be measured when running;

[0010] The actual pump head is substituted into the first function formula and the second function formula respectively, and corresponding pump shaft power reference value and pump efficiency reference value are calculated;

[0011] An actual pump shaft power of the centrifugal pump to be measured is obtained;

[0012] Based on the pump shaft power reference value, the pump efficiency reference value and the actual pump shaft power, an actual pump efficiency of the centrifugal pump to be measured is calculated; the actual pump efficiency = (the pump shaft power reference value / the actual pump shaft power) * the pump efficiency reference value.

[0013] Optionally, before obtaining the first function formula and the second function formula matched with the centrifugal pump to be measured from the database, the method further comprises:

[0014] A performance data set of a centrifugal pump to be measured under a standard performance state is obtained; the performance data set comprises a plurality of groups of one-to-one corresponding pump head, pump shaft power and pump efficiency; the centrifugal pump to be measured and the centrifugal pump to be measured belong to the same type;

[0015] Based on the performance data set, the first function formula and the second function formula are respectively established by mathematical fitting, and the key identification information of the centrifugal pump to be measured, the first function formula and the second function formula are stored in the database.

[0016] Optionally, the first function formula is as follows:

[0017]

[0018] In the formula, is the pump shaft power; is the pump head; c n is a constant coefficient, and n is the order of the polynomial;

[0019] The second function formula is as follows:

[0020] In the formula, is the pump efficiency; is the pump head, is a constant coefficient; n is the order of the polynomial.

[0021] Optionally, the actual pump head of the centrifugal pump to be measured when running is obtained, comprising:

[0022] The first fluid static pressure value of a first measuring point on an outlet pipeline of the centrifugal pump to be measured and the second fluid static pressure value of a second measuring point on an inlet pipeline are measured;

[0023] The vertical height difference between the first measuring point and the second measuring point is obtained.

[0024] calculating an actual pump head based on the first fluid static pressure value, the second fluid static pressure value and the vertical height difference; the actual pump head = the first fluid static pressure value - the second fluid static pressure value + the vertical height difference.

[0025] Optionally, the actual pump shaft power of the centrifugal pump under operation is obtained by:

[0026] measuring the electric power of a driving motor connected to the centrifugal pump under operation;

[0027] obtaining the motor efficiency of the driving motor, and the transmission efficiency of a transmission device between the driving motor and the centrifugal pump under operation;

[0028] multiplying the electric power, the motor efficiency and the transmission efficiency to obtain the actual pump shaft power.

[0029] Optionally, the transmission efficiency is obtained according to the type of the transmission device according to the following rules:

[0030] when the transmission device is a direct connection structure, the transmission efficiency is 1.0;

[0031] when the transmission device is a shaft coupling, the transmission efficiency is 0.95 to 0.98;

[0032] when the transmission device is a triangular belt, the transmission efficiency is 0.9 to 0.95;

[0033] when the transmission device is a flat belt, the transmission efficiency is 0.85.

[0034] In a second aspect, the present application provides a system for measuring the efficiency of an agricultural irrigation electric centrifugal pump, comprising:

[0035] a driving motor connected to a centrifugal pump under operation through a transmission device, for providing power for the operation of the centrifugal pump under operation;

[0036] a pump outlet pressure gauge installed at a first measuring point on an outlet pipeline of the centrifugal pump under operation, for measuring a first fluid static pressure value at the first measuring point and sending the first fluid static pressure value to a centrifugal pump efficiency calculation device through an instrument data transmission line;

[0037] a pump inlet pressure gauge installed at a second measuring point on an inlet pipeline of the centrifugal pump under operation, for measuring a second fluid static pressure value at the second measuring point and sending the second fluid static pressure value to the centrifugal pump efficiency calculation device through the instrument data transmission line;

[0038] a digital inductive power meter for measuring the electric power of the driving motor and sending the electric power of the driving motor to the centrifugal pump efficiency calculation device through RS-485 data transmission line;

[0039] the centrifugal pump efficiency calculation device, which is in communication connection with the pump outlet pressure gauge, the pump inlet pressure gauge and the digital inductive power meter respectively, is used for receiving the first fluid static pressure value, the second fluid static pressure value, the electric power of the driving motor and the user input parameter data, and executing the pump efficiency calculation method of the agricultural irrigation electric centrifugal pump as described in any one of the first aspect; wherein the user input parameter data includes the vertical height difference between the first measuring point and the second measuring point, the transmission efficiency of the transmission device and the motor efficiency of the driving motor.

[0040] Optionally, the centrifugal pump efficiency calculation device comprises:

[0041] a programmable function storage and calculation module for receiving the first fluid static pressure value, the second fluid static pressure value, the electric power of the driving motor and the user input parameter data, and executing the pump efficiency calculation method of the agricultural irrigation electric centrifugal pump as described in any one of the first aspect;

[0042] a power module which is a rechargeable battery or a power conversion circuit adapted to 220V alternating current, for providing power;

[0043] a data input and display module for receiving the user input parameter data and displaying the actual pump efficiency of the measured centrifugal pump.

[0044] Optionally, the data input and display module is further used for:

[0045] when the power module is a rechargeable battery, displaying the remaining power of the power module;

[0046] when the remaining power is less than the preset power, displaying an alarm information.

[0047] Optionally, the distance between the first measuring point and the outlet flange of the centrifugal pump to be measured is 5 to 10 times of the inner diameter of the outlet pipeline, the first measuring point is located before the flow regulating valve and the distance between the first measuring point and the flow regulating valve is 3 to 8 times of the inner diameter of the outlet pipeline; the distance between the second measuring point and the inlet flange of the centrifugal pump to be measured is 3 to 10 times of the inner diameter of the inlet pipeline.

[0048] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0049] The application provides a method for measuring the efficiency of an agricultural irrigation electric centrifugal pump, which comprises the following steps: obtaining a first function relationship and a second function relationship matched with a centrifugal pump to be measured from a database; the first function relationship is used to describe the mapping relationship between the pump head and the pump shaft power; the second function relationship is used to describe the mapping relationship between the pump head and the pump efficiency; the actual pump head of the centrifugal pump to be measured during operation is substituted into the first function relationship and the second function relationship respectively, and the corresponding pump shaft power reference value and pump efficiency reference value are calculated; and the actual pump efficiency of the centrifugal pump to be measured is calculated based on the pump shaft power reference value, the pump efficiency reference value and the actual pump shaft power of the centrifugal pump to be measured during operation. The method can dynamically calculate and output the actual pump efficiency by pre-building the database containing the mapping relationship among the pump head, the pump shaft power and the pump efficiency and collecting real-time data on site, without the pump flow, so that the expensive pump flow measuring device is not needed, the problem that the pump efficiency monitoring cannot be performed by the majority of small and medium-sized agricultural irrigation users due to high cost is solved, the pump efficiency online monitoring technology can be popularized and applied on a large scale, and the user or the manager can know whether the pump is operated in the high-efficiency area at any time according to the actual pump efficiency, and the problem of low efficiency caused by equipment wear, working condition deviation (for example, improper valve opening) and the like can be found in time. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the example embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:

[0051] Figure 1 The flowchart of the method for measuring the efficiency of the agricultural irrigation electric centrifugal pump provided by the embodiment of the application is shown in the figure;

[0052] Figure 2 The fitting relationship among the pump head, the pump shaft power and the pump efficiency provided by the embodiment of the application is shown in the figure;

[0053] Figure 3 The structural schematic diagram of the measuring system for the efficiency of the agricultural irrigation electric centrifugal pump provided by the embodiment of the application is shown in the figure;

[0054] Figure 4 The structural schematic diagram of the centrifugal pump efficiency calculation device provided by the embodiment of the application is shown in the figure.

[0055] Reference signs:

[0056] 1 - centrifugal pump; 2 - transmission device; 3 - driving motor; 4 - digital induction power meter; 5 - motor power supply cable; 6 - RS-485 data transmission line; 7 - centrifugal pump efficiency calculation device; 8 - wireless data transmission link; 9 - network cloud platform; 10 - data transmission line; 11 - other system monitoring equipment; 12 - instrument data transmission line; 13 - pump inlet pressure gauge; 14 - pump outlet pressure gauge. DETAILED DESCRIPTION

[0057] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with embodiments and drawings, the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and do not limit the present application.

[0058] In order to solve the problem that small and medium-sized agricultural irrigation users cannot perform pump efficiency monitoring due to high cost, the present application provides a method for measuring efficiency of an agricultural irrigation electric centrifugal pump. Figure 1 A flowchart of the method for measuring efficiency of the agricultural irrigation electric centrifugal pump provided by the present application is shown in FIG. 1. Figure 1 The method for measuring efficiency of the agricultural irrigation electric centrifugal pump is introduced as follows.

[0059] S1, obtaining a first function relationship and a second function relationship matched with the centrifugal pump to be measured from a database.

[0060] In the specific implementation process, the first function relationship and the second function relationship associated with various types of centrifugal pumps are pre-stored in the database, and the matched first function relationship and the second function relationship can be found from the database according to the type of the centrifugal pump to be measured. The first function relationship is used to describe the mapping relationship between the pump head and the pump shaft power; and the second function relationship is used to describe the mapping relationship between the pump head and the pump efficiency.

[0061] In one possible embodiment, the database is established as follows:

[0062] Obtaining a performance data set of the centrifugal pump to be measured under a standard performance state; based on the performance data set, the first function relationship and the second function relationship are respectively established through mathematical fitting, and the key identification information of the centrifugal pump to be measured, the first function relationship and the second function relationship are associated and stored in the database.

[0063] In practical implementation, the centrifugal pump under test refers to a centrifugal pump of the same type as the one being tested, which has undergone standard performance testing. Standard performance conditions refer to the operating state of the centrifugal pump under test, determined through standard performance testing under the rated operating conditions (such as rated speed and pumping clean water) set by the manufacturer. The performance dataset includes multiple sets of one-to-one corresponding pump head, pump shaft power, and pump efficiency. Pump head refers to the energy increment gained per unit weight of liquid flowing through the centrifugal pump; pump shaft power refers to the input mechanical power required to drive the centrifugal pump shaft to rotate; pump efficiency is the ratio of the effective output power of the centrifugal pump (i.e., the water power converted into liquid energy) to the pump shaft power.

[0064] There are several ways to obtain performance datasets, which are described below:

[0065] The first method involves extracting the relationship data between pump head, pump shaft power, and pump efficiency from the performance parameter data or performance curves of the corresponding model of centrifugal pump provided by the manufacturer of the centrifugal pump being tested, in order to form a performance dataset.

[0066] The second method involves extracting the relationship data between pump head, pump shaft power, and pump efficiency from the test report issued by the testing unit after conducting standard performance tests on the centrifugal pump under test, in order to form a performance dataset.

[0067] After obtaining the performance dataset, the pump head As the independent variable, with the corresponding pump efficiency As the dependent variable, multiple groups in the performance dataset ( The data points are fitted with a univariate polynomial to obtain the first functional relationship, as shown below:

[0068]

[0069] In the formula: Pump shaft power; For pump head; c n Let be the constant coefficients determined through fitting, and n be the order of the polynomial.

[0070] After obtaining the performance dataset, the pump head As the independent variable, with the corresponding pump shaft power As the dependent variable, multiple groups in the performance dataset ( The data points are fitted with a univariate polynomial to obtain the second functional relationship, as shown in the following expression:

[0071]

[0072] In the formula, For pump efficiency; For pump head, is a constant coefficient determined by fitting; n is the order of the polynomial.

[0073] Through analysis of the actual pump performance curve, the order n of fitting is usually selected between 2 and 6, that is, the fitting accuracy can be ensured while overfitting is avoided. In general, when n≦6, the minimum variance of data fitting can meet greater than 0.99.

[0074] The first function relationship (pump head-pump efficiency relationship) and the second function relationship (pump head-pump shaft power relationship) fitted by the measured centrifugal pump, together with the key identification information (such as the manufacturer, pump model, and factory date) of the centrifugal pump, are stored as a complete record in the database of the network cloud platform. Through long-term accumulation, the reference performance function relationship (the first function relationship and the second function relationship) of centrifugal pumps of different manufacturers and different models is continuously stored in the database, and eventually a database covering almost all centrifugal pump manufacturers, pump models, and pump factory dates on the market is formed. Users can query, use, and download from the database through the network.

[0075] S2, obtaining the actual pump head of the centrifugal pump to be measured when running.

[0076] In a possible embodiment, the first fluid static pressure value of the first measuring point on the outlet pipe of the centrifugal pump to be measured and the second fluid static pressure value of the second measuring point on the inlet pipe are measured; the vertical height difference between the first measuring point and the second measuring point is obtained; and the actual pump head is calculated based on the first fluid static pressure value, the second fluid static pressure value, and the vertical height difference.

[0077] In the specific implementation process, the calculation formula of the actual pump head is as follows:

[0078]

[0079] wherein, is the actual pump head; is the first fluid static pressure value; is the second fluid static pressure value; is the vertical height difference.

[0080] S3, substituting the actual pump head into the first function relationship and the second function relationship respectively, to calculate the corresponding pump shaft power reference value and pump efficiency reference value.

[0081] In the specific implementation process, the actual pump head is substituted into the first function relationship to calculate the pump shaft power reference value corresponding to the actual pump head, and the actual pump head is substituted into the second function relationship to calculate the pump efficiency reference value corresponding to the actual pump head.

[0082] S4, obtaining the actual pump shaft power of the centrifugal pump when running.

[0083] In one possible embodiment, the electrical power of the drive motor connected to the centrifugal pump under test is measured; the motor efficiency of the drive motor and the transmission efficiency of the transmission device between the drive motor and the centrifugal pump under test are obtained; the electrical power, motor efficiency and transmission efficiency are multiplied to obtain the actual pump shaft power.

[0084] In practical implementation, the formula for calculating the actual pump shaft power is as follows:

[0085]

[0086] In the formula, This refers to the actual pump shaft power. The electrical power of the drive motor; The efficiency of the drive motor; The transmission efficiency of the transmission device.

[0087] Motor efficiency refers to the efficiency with which a drive motor converts input electrical energy into output mechanical energy. This efficiency value varies depending on the motor model, load rate, and manufacturer, typically ranging from 0.85 to 0.98. In practical applications, the motor efficiency can be obtained by consulting the corresponding product technical manual provided by the drive motor manufacturer.

[0088] In this embodiment of the application, the measured motor power ( ), and successively deduct the motor's own losses (from (reflection) and transmission losses (by) The reflection ultimately yields the actual mechanical power transmitted to the pump shaft. In this way, low-cost and highly feasible indirect measurement of pump shaft power can be achieved without the need to install expensive equipment such as torque sensors.

[0089] Different transmission methods have different transmission efficiencies. In one possible embodiment, the transmission efficiency is determined according to the following rules based on the type of transmission device:

[0090] When the transmission device is a direct-drive structure, the transmission efficiency is taken as 1.0;

[0091] When the transmission device is a coupling, the transmission efficiency is between 0.95 and 0.98.

[0092] When the transmission device is a V-belt, the transmission efficiency is between 0.9 and 0.95.

[0093] When the transmission device is a flat belt, the transmission efficiency is 0.85.

[0094] In the embodiments of the present application, the recommended efficiency value range of different transmission types (direct connection, coupling, triangular belt, flat belt) (such as 1.0 for direct connection, 0.95-0.98 for coupling, etc.) is defined in advance, and the complex field transmission loss evaluation is converted into a simple type selection and numerical substitution problem. The implementer does not need to perform professional testing or complex calculation, and can quickly and uniformly determine the transmission efficiency parameter, greatly reducing the complexity of field implementation and the technical requirements for the operator.

[0095] S5, based on the pump shaft power reference value, the pump efficiency reference value and the actual pump shaft power, the actual pump efficiency of the centrifugal pump to be measured is calculated and obtained.

[0096] In the specific implementation process, the calculation formula of the actual pump efficiency is as follows:

[0097]

[0098] Among them, is the actual pump efficiency; is the pump shaft power reference value; is the pump efficiency reference value; is the actual pump shaft power.

[0099] Taking the type of the measured centrifugal pump as an example, the type of the measured centrifugal pump is 8SA-10 (S200-63), the actual pump head of the measured centrifugal pump is 67mH2O, the power of the driving motor is 70.1kW, in the embodiment, the measured centrifugal pump and the driving motor adopt the direct connection mode of the coupling, therefore the value of the transmission efficiency is 0.97. In the embodiment, the driving motor adopts Y280S-2 type 75kW three-phase asynchronous motor, according to the product technical manual, the value of the motor efficiency is 0.92. The height difference between the first measuring point and the second measuring point is 0. Adopting the agricultural irrigation electric centrifugal pump efficiency measuring method provided in the present application, the pump shaft power reference value is 56.1kW, the pump efficiency reference value is 78.5%, and the actual pump efficiency of the measured centrifugal pump is 70.3%.

[0100] According to the principle of fluid mechanics, for a fluid conveying pipeline system with a certain state, the fluid pressure at the inlet of the pipeline and the pipeline flow rate present a monotonic corresponding relationship. For the actual pipeline system existing in the field, when the state of the flow control valve is unchanged, the pipeline flow rate should also be the same when the system inlet fluid pressure is the same. Therefore, the present application provides an agricultural irrigation electric centrifugal pump efficiency measuring method, which uses a comparative calculation method to calculate the efficiency of the actual centrifugal pump in the field by using part of the actual operating parameters of the pump measured on site according to the performance parameters of the same type standard centrifugal pump. The calculation method is simple and fast.

[0101] ​Based on the same inventive concept, please refer to Figure 3 The application also provides a measuring system for the efficiency of an agricultural irrigation electric centrifugal pump, comprising:

[0102] A driving motor 3 is connected to the centrifugal pump 1 to be measured through a transmission device 2, and is used to provide power for the operation of the centrifugal pump 1 to be measured;

[0103] A pump-out pressure gauge 14 is installed at a first measuring point on the outlet pipeline of the centrifugal pump 1 to be measured, and is used to measure a first fluid static pressure value at the first measuring point and send the first fluid static pressure value to the centrifugal pump efficiency calculation device 7 through the instrument data transmission line 12;

[0104] A pump-in pressure gauge 13 is installed at a second measuring point on the inlet pipeline of the centrifugal pump 1 to be measured, and is used to measure a second fluid static pressure value at the second measuring point and send the second fluid static pressure value to the centrifugal pump efficiency calculation device 7 through the instrument data transmission line 12;

[0105] A digital induction power meter 4 is used to measure the electric power of the driving motor 3 and send the electric power of the driving motor 3 to the centrifugal pump efficiency calculation device 7 through the RS-485 data transmission line 6;

[0106] The centrifugal pump efficiency calculation device 7 is in communication connection with the pump-out pressure gauge 14, the pump-in pressure gauge 13 and the digital induction power meter 4 respectively, and is used to receive the first fluid static pressure value, the second fluid static pressure value, the electric power of the driving motor 3 and the parameter data input by the user, and execute the pump efficiency calculation method of the agricultural irrigation electric centrifugal pump as described in Figure 1 ; wherein the parameter data input by the user includes the vertical height difference between the first measuring point and the second measuring point, the transmission efficiency of the transmission device 2 and the motor efficiency of the driving motor 3.

[0107] Specifically, the model of the centrifugal pump 1 to be measured is, for example, 8SA-10 (S200-63), the transmission device 2 is, for example, a shaft coupling, and the driving motor 3 is, for example, a Y280S-2 type 75kW three-phase asynchronous motor.

[0108] Optionally, the digital induction electric power meter 4 can be directly connected in series with the power supply cable 5 of the driving motor 3 through an electric power meter, and the electric power of the driving motor 3 is measured by a direct measurement method, and the electric power of the driving motor 3 can also be measured by an electromagnetic induction principle.

[0109] Optionally, the measuring system further comprises a network cloud platform 9, and the network cloud platform 9 comprises a database, and the database stores the first function relationship formula and the second function relationship formula associated with various types of centrifugal pumps.

[0110] Specifically, the centrifugal pump efficiency calculation device 7 can download the first function formula and the second function formula matched with the centrifugal pump 1 to be measured from a database on the network cloud platform 9 through a wireless data transmission link 8.

[0111] Optionally, the distance between the first measuring point and the outlet flange of the centrifugal pump 1 to be measured is 5 to 10 times the inner diameter of the outlet pipeline, the first measuring point is located before the flow regulating valve, and the distance between the first measuring point and the flow regulating valve is 3 to 8 times the inner diameter of the outlet pipeline; the distance between the second measuring point and the inlet flange of the centrifugal pump 1 to be measured is 3 to 10 times the inner diameter of the inlet pipeline.

[0112] Please refer to Figure 4 The centrifugal pump efficiency calculation device provided in the embodiment of the present application comprises:

[0113] The programmable function storage and calculation module is configured to receive the first fluid static pressure value, the second fluid static pressure value, the electric power of the driving motor, and the parameter data input by the user, and execute the pump efficiency calculation method of the agricultural irrigation electric centrifugal pump as described above. Figure 1 The pump efficiency calculation method of the agricultural irrigation electric centrifugal pump as described above;

[0114] The power module is a rechargeable battery or a power conversion circuit adapted to 220V alternating current, and is configured to provide electric power.

[0115] The data input and display module is configured to receive the parameter data input by the user, and display the actual pump efficiency of the centrifugal pump to be measured.

[0116] Specifically, the user can input the parameter data through the data input and display module according to the actual situation on site, including the vertical height difference between the first measuring point and the second measuring point, the transmission efficiency of the transmission device, and the motor efficiency of the driving motor. The programmable function storage and calculation module can execute the pump efficiency calculation method of the agricultural irrigation electric centrifugal pump provided in the present application according to the first fluid static pressure value, the second fluid static pressure value, the electric power of the driving motor, and the parameter data input by the user, to obtain the actual pump efficiency of the centrifugal pump 1 to be measured.

[0117] Further, the programmable function storage and calculation module can send the actual pump efficiency of the centrifugal pump 1 to be measured to the data input and display module for display, and can also output to other system monitoring devices 11 through the data transmission line 10.

[0118] Optionally, the data input and display module is further configured to:

[0119] When the power module is a rechargeable battery, the remaining power of the power module is displayed.

[0120] When the remaining power is less than the preset power, an alarm information is displayed.

[0121] It should be noted that the centrifugal pump efficiency calculation device in the embodiment corresponds to each step in the agricultural irrigation electric centrifugal pump efficiency measurement method in the foregoing embodiment one by one, and therefore, the specific implementation of the embodiment can refer to the implementation of the foregoing agricultural irrigation electric centrifugal pump efficiency measurement method, which will not be described herein again.

[0122] In summary, the application provides an agricultural irrigation electric centrifugal pump efficiency measurement system, which completely discards the high-precision flow measurement device indispensable in the conventional pump efficiency monitoring, and instead uses a conventional industrial pressure gauge and an electric power meter. The hardware of the complete system is simple, and the procurement and installation costs are greatly reduced, so that the monitoring cost of pump efficiency can be borne by the majority of small and medium-sized agricultural irrigation users, and the popularization of the pump efficiency online monitoring technology is truly realized.

[0123] Based on the same inventive concept, the application further provides a computer device, which comprises a processor, a memory, and a computer program stored in the memory, and the computer program realizes the foregoing agricultural irrigation electric centrifugal pump efficiency measurement method when executed by the processor.

[0124] Based on the same inventive concept, the application further provides a computer storage medium, which stores a computer program, and the computer program realizes the foregoing agricultural irrigation electric centrifugal pump efficiency measurement method when executed by a processor.

[0125] In some embodiments, the computer readable storage medium can be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disc, or CD-ROM; or various devices including one or any combination of the above memories. The computer can be various computing devices including smart terminals and servers.

[0126] In some embodiments, the executable instructions can be in the form of programs, software, software modules, scripts or codes, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and can be deployed in any form, including being deployed as independent programs or as modules, components, subroutines or other units suitable for use in a computing environment.

[0127] As an example, the executable instructions can but not necessarily correspond to files in a file system, can be stored in a part of a file storing other programs or data, for example, stored in one or more scripts in a Hyper Text Markup Language (HTML) document, stored in a single file dedicated to the program in question, or stored in multiple cooperative files (for example, files storing one or more modules, subroutines or code portions).

[0128] By way of example, the executable instructions can be deployed in one computing device or in a plurality of computing devices located at one site or distributed across multiple sites and interconnected by a communication network.

[0129] It has to be remarked that, in this text, the terms "comprising", "including", or any other variant thereof, are intended to cover a non-exclusive inclusion, such that processes, methods, articles, or systems that comprise a list of elements are not limited to those elements, but can include other elements not expressly listed, or inherent to such processes, methods, articles, or systems. Without further limitation, an element preceded by "comprising" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or system that comprises the recited element.

[0130] The above-mentioned sequence numbers of the embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0131] The above detailed description merely describes the specific implementation of the present application. It is to be understood that this detailed description does not limit the protection scope of the present application, and any modification, equivalent replacement, improvement, 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 method of calculating the pump efficiency of an electric centrifugal pump for agricultural irrigation, characterized in that, The method comprises the following steps: obtaining a first function relationship and a second function relationship matched with the centrifugal pump to be tested from a database; the first function relationship is used to describe the mapping relationship between the pump head and the pump shaft power; the second function relationship is used to describe the mapping relationship between the pump head and the pump efficiency; obtaining the actual pump head of the centrifugal pump to be tested during operation; substituting the actual pump head into the first function relationship and the second function relationship respectively, and calculating the corresponding pump shaft power reference value and pump efficiency reference value; obtaining the actual pump shaft power of the centrifugal pump to be tested during operation; based on the pump shaft power reference value, the pump efficiency reference value and the actual pump shaft power, the actual pump efficiency of the centrifugal pump to be tested is calculated; the actual pump efficiency = (the pump shaft power reference value / the actual pump shaft power) x the pump efficiency reference value.

2. The method of claim 1, wherein, Before obtaining the first function relationship and the second function relationship matched with the centrifugal pump to be tested from the database, the method further comprises the following steps: obtaining the performance data set of the measured centrifugal pump under the standard performance state; the performance data set comprises a plurality of groups of one-to-one corresponding pump head, pump shaft power and pump efficiency; the measured centrifugal pump and the centrifugal pump to be tested belong to the same type; based on the performance data set, the first function relationship and the second function relationship are respectively established by mathematical fitting, and the key identification information of the measured centrifugal pump, the first function relationship and the second function relationship are stored in the database.

3. The method of claim 1, wherein, The first function relationship is as follows: ； In the formula: P is the pump shaft power; H is the pump head; c n is a constant coefficient, and n is the order of the polynomial; The second function relationship is as follows: ； wherein is the pump efficiency; is the pump head, is a constant coefficient; n is the order of the polynomial.

4. The method of claim 1, wherein, The actual pump head of the centrifugal pump to be tested during operation is obtained, which comprises the following steps: measuring the first fluid static pressure value of the first measuring point on the outlet pipeline of the centrifugal pump to be tested and the second fluid static pressure value of the second measuring point on the inlet pipeline; obtaining the vertical height difference between the first measuring point and the second measuring point; based on the first fluid static pressure value, the second fluid static pressure value and the vertical height difference, the actual pump head is calculated; the actual pump head = the first fluid static pressure value-the second fluid static pressure value + the vertical height difference.

5. The method of claim 1, wherein, The actual pump shaft power of the centrifugal pump to be tested during operation is obtained, which comprises the following steps: measuring the electric power of the driving motor connected with the centrifugal pump to be tested; obtaining the motor efficiency of the driving motor, the transmission efficiency of the transmission device between the driving motor and the centrifugal pump to be tested; multiplying the electric power, the motor efficiency and the transmission efficiency to obtain the actual pump shaft power.

6. The method of claim 5, wherein the pump efficiency of the agricultural irrigation electric centrifugal pump is calculated by the following equation: ###0001### where, P = pump efficiency, Q = flow rate, H = head, and N = rotational speed of the pump. 5 The transmission efficiency is valued according to the type of the transmission device as follows: when the transmission device is a direct connection structure, the transmission efficiency is 1.0; when the transmission device is a shaft coupling, the transmission efficiency is 0.95 to 0.98; when the transmission device is a triangular belt, the transmission efficiency is 0.9 to 0.95; when the transmission device is a flat belt, the transmission efficiency is 0.

85.

7. A system for calculating the pump efficiency of an electric centrifugal pump for agricultural irrigation, characterized by The method comprises the following steps: a driving motor connected with the centrifugal pump to be tested through a transmission device, used to provide power for the operation of the centrifugal pump to be tested; a pump-out pressure gauge installed at a first measuring point on an outlet pipe of the centrifugal pump to be measured, for measuring a first fluid static pressure value at the first measuring point and sending the first fluid static pressure value to the centrifugal pump efficiency calculation device through an instrument data transmission line; a pump-in pressure gauge installed at a second measuring point on an inlet pipe of the centrifugal pump to be measured, for measuring a second fluid static pressure value at the second measuring point and sending the second fluid static pressure value to the centrifugal pump efficiency calculation device through the instrument data transmission line; a digital induction power meter for measuring the electric power of the driving motor and sending the electric power of the driving motor to the centrifugal pump efficiency calculation device through an RS-485 data transmission line; the centrifugal pump efficiency calculation device is in communication connection with the pump-out pressure gauge, the pump-in pressure gauge and the digital induction power meter respectively, for receiving the first fluid static pressure value, the second fluid static pressure value, the electric power of the driving motor and the user-input parameter data, and executing the pump efficiency calculation method of the agricultural irrigation electric centrifugal pump according to any one of claims 1-6; wherein the user-input parameter data includes the vertical height difference between the first measuring point and the second measuring point, the transmission efficiency of the transmission device and the motor efficiency of the driving motor.

8. The system for estimating the efficiency of an agricultural irrigation electric centrifugal pump according to claim 7, characterized in that, the centrifugal pump efficiency calculation device comprises: a programmable function storage and calculation module for receiving the first fluid static pressure value, the second fluid static pressure value, the electric power of the driving motor and the user-input parameter data, and executing the pump efficiency calculation method of the agricultural irrigation electric centrifugal pump according to any one of claims 1-6; a power module which is a rechargeable battery or a power conversion circuit adapted to 220V alternating current, for providing power; a data input and display module for receiving user-input parameter data and displaying the actual pump efficiency of the centrifugal pump to be measured.

9. The system for estimating the efficiency of an agricultural irrigation electric centrifugal pump according to claim 8, characterized in that, the data input and display module is further used for: when the power module is a rechargeable battery, displaying the remaining power of the power module; when the remaining power is less than a preset power, displaying an alarm information.

10. The system for estimating the efficiency of an agricultural irrigation electric centrifugal pump according to claim 9, characterized in that, the distance between the first measuring point and the outlet flange of the centrifugal pump to be measured is 5 to 10 times the inner diameter of the outlet pipe, the first measuring point is located before the flow regulating valve, and the distance between the first measuring point and the flow regulating valve is 3 to 8 times the inner diameter of the outlet pipe; the distance between the second measuring point and the inlet flange of the centrifugal pump to be measured is 3 to 10 times the inner diameter of the inlet pipe.

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