WO2025109639A1

WO2025109639A1 - Method and system for evaluating the energy performance of a pumping unit

Info

Publication number: WO2025109639A1
Application number: PCT/IT2024/050239
Authority: WO
Inventors: Giacomo FREZZA
Original assignee: Caprari SpA
Current assignee: Caprari SpA
Priority date: 2023-11-22
Filing date: 2024-11-20
Publication date: 2025-05-30
Anticipated expiration: 2026-05-22

Abstract

The method for evaluating the energy performance of a pumping unit comprises the step of acquiring first values related to at least one pair of parameters of said pumping unit, said at least one pair of parameters being measured during a test of said pumping unit, said first values being indicative of an optimal operation of said pumping unit. The method further comprises the step of acquiring second values related to at least one pair of parameters of said pumping unit, said at least one pair of parameters being measured during an initial verification of the operation of said pumping unit in the system for which it is intended, said second values being indicative of an initial operation of said pumping unit in the system.

Description

METHOD AND SYSTEM FOR EVALUATING THE ENERGY PERFORMANCE OF A PUMPING UNIT

Technical field

[01] The present invention relates to a method and a system for evaluating the energy performance of a pumping unit, herein the pumping unit comprises a pump and an actuator member adapted to drive the pump in motion.

Prior art

[02] The need to monitor the operation of pumps, especially electric pumps, in the systems in which they are used has long been known in order to prevent any malfunctions and prevent system shutdowns. The malfunctions can be due to different factors, for example construction defects of a component of the electric pump or problems related to the system (leaks in the pipes, change in the dynamic level of the sump over time, etc.).

[03] Therefore, several systems and related methods have been developed for monitoring the operation of a pump.

[04] International application WO2020253926 discloses a computer-implemented system for controlling and monitoring a pump system. The system comprises at least one pump, a sensor adapted to provide signals representative of an operation state of the pump from a mechanical, fluid and electrical point of view and a control module arranged to control the status of the pump in response to the signals received. The system further envisages a digital module comprising an API for processing the data and an archive in which the digital module receives signals indicative of the operation state of the pump and stores the data in the archive. The digital module communicates with a chatbot agent which is configured to communicate with the API and a user. The chatbot agent, at the user's request, provides information on the current or historical state of the pump by using the digital module API, extracting information from the archive, and transmits a control signal to the pump system to set the pump to a requested operation state. The chatbot agent helps the user to identify the correct control parameter to send a control signal to the pump system which modifies the operation state thereof. The digital module can be used to forecast the future operation of the pump based on data present in the archive or data from sensors and the forecast is made using machine learning algorithms or artificial intelligence.

[05] A further example of a method for monitoring an electric pump is illustrated in international application W02023/020998. The method has the aim of detecting a fault in a centrifugal pump, in particular a blockage of the impeller member, and envisages evaluating at least one harmonic of the current of the electric motor driving the pump. The method is based on the fact that mechanical damage to the pump or to the drive motor affects certain frequencies in the current spectrum. The method is implemented in a pump data processing unit or an external data processing unit. Also disclosed is a system comprising a pump implementing the aforesaid method for calculating a damage factor and transmitting it, by means of a gateway, to a cloud-based external unit.

[06] The solutions developed for monitoring a pump mainly have the objective of checking if there are faults in the pump but have not been specifically designed to reduce energy consumption.

[07] Patent application GB 2313197 illustrates a method for evaluating the performance of a pump which envisages determining the flow rate of the pump and measuring the head. Subsequently, the method envisages comparing the flow rate and head results with the flow rate and head data obtained in initial conditions or in optimal conditions. The step of determining the pump flow rate envisages obtaining information on the power consumed by the pump and reading the corresponding flow rate value from the curve provided by the manufacturer, carrying out appropriate calculations to obtain a more accurate flow rate value.

[08] A problem with the disclosed method is that it does not allow a sufficiently accurate evaluation to be carried out, as it necessarily requires evaluating the problems of the installation system in order to be able to compare the power consumed to the power measured by the manufacturer, or to the power flow rate curve provided by the manufacturer, therefore, errors may occur. For example, any power losses in the system or further problems which can affect the power consumed must be considered. Furthermore, the method envisages measuring the head and this means that appropriate calculations must be made on the pressures found in the system. The latter aspect can further introduce errors in evaluating the performance of the pump.

[09] The problem of energy efficiency in the industrial field has significant importance, which has become even greater in recent years. Therefore, the need is felt to devise new pump monitoring solutions which allow minimizing energy consumption.

Presentation of the invention

[10] The task of the present invention is to solve the aforementioned problems, devising a method for evaluating the energy performance of a pumping unit which allows optimizing the energy consumption related to the management of the system in which the unit is installed.

[11] Within the scope of such a task, it is a further object of the present invention to provide a method for evaluating the energy performance of a pumping unit which provides direct and easily understandable information to the monitoring operators regarding any corrective actions to be taken to reduce energy consumption.

[12] It is further an object of the present invention to devise a method which allows accurately evaluating the energy performance of a pumping unit.

[13] A further object of the present invention is to devise a method for evaluating the energy performance of a pumping unit which allows the operating life of the pumping unit to be increased.

[14] Another object of the invention is to provide a method which allows identifying any malfunctions of the pumping unit.

[15] The cited objects are achieved, according to the present invention, by the method for evaluating the energy performance of a pumping unit according to claim 1 and by the system for evaluating the energy performance of a pumping unit according to claim 9, as well as by the computer program according to claim 12.

[16] The method for evaluating the energy performance of a pumping unit implemented by means of an electronic computer comprises the step of acquiring first values related to at least one pair of parameters of said pumping unit, said at least one pair of parameters being measured during a test of said pumping unit, said first values being indicative of an optimal operation of said pumping unit.

[17] Preferably, said first values are measured during a test of said pumping unit with a procedure established by current legislation. The method then envisages the step of acquiring second values related to at least one pair of parameters of said pumping unit, said at least one pair of parameters being measured during an initial verification of the operation of said pumping unit in the system for which it is intended, said second values being indicative of an initial operation of said pumping unit in the system.

[18] The step of acquiring second values related to at least one pair of parameters of said pumping unit during an initial verification of the operation of said pumping unit in the system allows the pumping unit to be "contextualized" within the system in a simple and accurate manner.

[19] The method then envisages comparing said first values with said second values and deriving reference values indicative of the difference between said first values and said second values.

[20] In a use phase of said pumping unit in said system, the method envisages continuously acquiring third values related to at least one pair of parameters of said pumping unit.

[21] Finally, the method comprises the step of continuously comparing said third values with said second values and reporting an irregularity if the difference between said third values and said second values is greater than the identified reference value.

[22] The method allows optimizing energy consumption, as it envisages continuously comparing the third values, which give information on the working point of the pumping unit, and the second values, having a reference value which must not be exceeded.

[23] It should be noted that a prerogative of the method according to the present invention is the fact of acquiring first values related to at least one pair of parameters of the pumping unit, measured during a test of said pumping unit, and acquiring second values related to at least one pair of parameters of said pumping unit measured during an initial verification of the operation of said pumping unit in the system for which it is intended and then comparing the second values with the first values. Obtaining reference values, by comparing the first values with the second values, makes the method simple since it is enough to compare the third values of at least one pair of parameters of the pumping unit, acquired in a use phase, with the second values, using the reference values, to obtain information on the energy performance of the pumping unit in the system. In this regard, it should be noted that the parameters of the pumping unit acquired, which can be for example the gauge pressure and the flow rate for the second and third values, are sufficient for evaluating the correct operation of the system and it is not necessary to have further information on the system, therefore, thorough knowledge of the system is not required. If the pumping unit parameters acquired comprise the head and the flow rate for the first values, the gauge pressure and the flow rate for the second and third values, and also the absorbed power, an evaluation of the energy performance of the system can be carried out. This last aspect is relevant because the number of parameters acquired is reduced and, therefore, also the possibility of measurement errors occurring, with a consequent greater accuracy in evaluating energy performance.

[24] A further aspect to be highlighted is that the first parameter values of the pumping unit are used to allow the interpretation of the parameter values acquired during use, by means of the comparison with the second values and obtaining the reference values. In use, the operator works with the second values and the third values of the parameters, which refer to the pumping unit in the system, with a consequent simplification of the work.

[25] Preferably the parameters comprise, in the case of said first values, the head and the flow rate of said pumping unit.

[26] Preferably, in the case of said second values and said third values, the parameters comprise the gauge pressure and the flow rate. It should be noted that the gauge pressure is the pressure measured by sensor means arranged at the delivery of the pumping unit and it is advantageous because these values are acquired directly on the system. Thereby, the operator must not use further data, for example the pressure drops of the system, reducing the possibility of errors occurring in a data entry step or due to non-detailed knowledge of the system.

[27] The method according to the present invention greatly facilitates the operator in the work of verifying the operation of the pumping unit because it actually provides information on the possible deviation of the gauge pressure, flow rate and preferably also absorbed power values, acquired by the sensor means present on the system, with respect to the same values measured during an initial verification of operation of the pumping unit in the system. The deviation can be due to numerous factors, for example the wear of the pump and/or the motor.

[28] Preferably the parameters further comprise one or more of the following parameters: the absorbed power, the temperature, the vibratory state of said pumping unit.

[29] Advantageously, if an electric pump controlled by a device is used to vary the speed of the motor member associated with the pump, the method envisages carrying out the steps of acquiring the first values and acquiring the second values at a first predetermined frequency, respectively, and also comprises the step of processing the first values and the second values, by means of affinity laws, to obtain corresponding first values and second values at a second frequency different from the first predetermined frequency.

[30] Advantageously, the method also envisages comparing said third values with predetermined values defining a performance range of said pumping unit, said predetermined values comprising a minimum flow rate (Qmin), a maximum flow rate (Qmax), a flow rate at which said pumping unit works with maximum hydraulic efficiency (QBEP), a flow rate at which said pumping unit works at 75% with respect to the flow rate measured at maximum hydraulic efficiency (QPL (Part Load)), a flow rate at which said pumping unit works at 110% with respect to the flow rate measured at maximum hydraulic efficiency (QOL (Over Load))-

[31] The aforesaid step allows easily verifying if the pumping unit is working in a range, comprised between QPL and QOL where the energy consumption is optimal. Furthermore, it is possible to verify whether the working flow rate of the pumping unit is close to the maximum performance flow rate QBEP.

[32] Preferably, the method comprises the step of defining a curve for said first values and for said second values, respectively.

[33] Preferably, the method comprises the step of defining a polynomial equation associated with a trend line which approximates said curve for said first values and for said second values, respectively.

[34] Preferably, the method further envisages displaying, by means of a user interface, said third values of the parameters of the pumping unit, in particular the gauge pressure, the flow rate and preferably also the power absorbed, at a predetermined time instant, and the second values.

[35] Preferably, said third values represent the working point of said pumping unit at a predetermined time instant.

[36] Preferably, the method envisages displaying, by means of said user interface, said working point at a predetermined time instant and the trend line which approximates the curve of said second values of the pumping unit. The display by means of a user interface facilitates the operator in understanding the data.

[37] Preferably, said method envisages displaying in real time, by means of said user interface, said third values and the trend line which approximates the curve of said second values.

[38] The present invention further relates to a system for evaluating the energy performance of a pumping unit comprising sensor means configured to measure values related to at least one pair of parameters of said pumping unit.

[39] Preferably, the system comprises transmission means configured to transmit the values measured by said sensor means to processing means.

[40] Preferably, the system comprises said processing means which are configured to perform the aforesaid steps of the method, in particular the steps of acquiring the first values and the second values, comparing the first values with the second values and deriving reference values indicative of the difference between the first and the second values, continuously acquiring, in a use phase of the pumping unit, third values related to at least one pair of parameters and continuously comparing said third values with the second values, reporting an irregularity if the difference is greater than the reference value identified.

[41] Preferably, the processing means are comprised in a cloud platform.

[42] Preferably, the sensor means comprise at least one flow sensor and at least one pressure sensor.

[43] The sensor means can also comprise a temperature measurement sensor and/or a sensor for measuring the vibratory state of the pump or of the motor member which drives the pump.

[44] Preferably, the system further comprises sensor means adapted to measure the following parameters: power factor, current asymmetry, isolation measurement, phase sequence, missing phase. In the case of using an electric pump of the submersible type, the system further comprises means for monitoring any failure in the degree of protection of the motor casing from water infiltration. In the case of using an electric pump, the system can further comprise a control device for varying the speed of the electric motor member adapted to drive the electric pump.

[45] Preferably, the system comprises a user interface, accessible by an operator responsible for managing the system in which the pumping unit is installed. The user interface can be the interface of an electronic device, for example a computer, a tablet or a smartphone which is in communication with the processing means.

[46] Preferably, the user interface allows to display, in real time, the third values of the parameters of the pumping unit, in particular the gauge pressure and the flow rate at a predetermined instant of time, which represents the working point of the pumping unit, and the trend line related to the second values of the pumping unit.

[47] Preferably, the user interface also allows displaying information on the operating hours of the pumping unit and/or on the number of total starts and/or on the number of starts which occurred in a predetermined time interval, preferably in one hour.

[48] The present invention further relates to a computer program comprising instructions which, when the program is run by an electronic computer, cause the electronic computer to carry out the following steps of the method of acquiring the first values and the second values; comparing the first values with the second values and deriving reference values indicative of the difference between the first and the second values; continuously acquiring, in a use phase of the pumping unit, third values related to at least one pair of parameters and continuously comparing said third values with the second values, reporting an irregularity if the difference is greater than the reference value identified.

Description of the drawings

[49] The details of the invention will become more apparent from the detailed description of a preferred embodiment of the method for evaluating the energy performance of a pumping unit according to the invention, illustrated by way of example in the accompanying drawings, wherein:

Figure 1 shows a block diagram of the method according to the invention;

Figures 2 and 3 respectively show two curves related to the head/gauge pressure of a pumping unit as a function of the flow rate, obtained under different operating conditions, and two curves related to the power absorbed by an electric pump as a function of the flow rate, also obtained under different operating conditions;

Figure 4 shows two curves related to the head/gauge pressure of a pumping unit as a function of the flow rate, obtained under different operating conditions, in which a working point of the pumping unit at a predetermined instant and some characteristic points of the performance range of the pumping unit are indicated;

Figure 5 shows two curves related to the power absorbed by an electric pump as a function of the flow rate, obtained under different operating conditions, in which a working point of the electric pump is indicated at a predetermined instant;

Figure 6 shows a curve related to the gauge pressure of a pumping unit as a function of the flow rate in which a working point of the pumping unit at a predetermined instant and some characteristic points of the performance range of the pumping unit are indicated;

Figure 7 shows a curve related to the power absorbed by an electric pump as a function of the flow rate in which a working point of the electric pump is indicated.

Description of embodiments of the invention

[50] With particular reference to such figures, the block diagram illustrating the steps of the method for evaluating the energy performance of a pumping unit according to the present invention is indicated as a whole with 1 .

[51] The term pumping unit is intended as a unit comprising a pump and an actuator member, wherein the actuator member is adapted to drive the pump in motion. The actuator member can be, for example, an endothermic motor, a hydraulic motor, an electric motor.

[52] Preferably, the method is indicated for monitoring and managing an electric pump, i.e., a pumping unit comprising a pump and an electric motor member adapted to drive the pump in motion. The method can obviously also be implemented for a different type of pumping unit.

[53] In the following description the term electric pump will be used with reference to a pumping unit comprising an electric motor and a pump.

[54] The method for evaluating the energy performance of a pumping unit is implemented by means of an electronic computer.

[55] The method first envisages the step of acquiring first values related to at least one pair of parameters of the pumping unit, wherein the parameters are measured during a test of the pumping unit (step a). The test is preferably carried out in a test room of the pump manufacturer. It is good practice to carry out this test using the procedure according to UNI EN ISO 9906.

[56] The first values, represented by diamond-shaped symbols in Figures 2-5, are indicative of optimal operation of the pumping unit.

[57] The first values are provided by the manufacturer to the customer and are related to the pumping unit which the customer has selected according to the needs of their system.

[58] Thereafter, the method envisages acquiring second values related to at least one pair of parameters of the pumping unit, wherein the parameters are measured during an initial verification of the operation of the unit in the system for which it is intended. In practice, the pumping unit is installed in the system where it will be used and a verification of its operation is carried out, measuring the aforesaid second values (step b), which are indicated with the circle and triangle symbols respectively in Figure 2 and Figure 3.

[59] The second values allow verifying how the system and the pumping unit interact by mutually influencing each other, therefore, they allow evaluating the influences of the system on the pumping unit.

[60] The parameters comprise, in the case of the first values, the head (indicated with H in Figures 2 and 4) and the flow rate (indicated with Q in Figures 2-7). The parameters, in the case of the second values, comprise the gauge pressure measured at the delivery of the pumping unit (indicated with H in Figures 2, 4 and 6) and the flow rate (indicated with Q in Figures 2-7). In the case of an electric pump, the parameters can also comprise the power (indicated with P in Figures 3, 5, and 7) absorbed as the flow rate varies. The values of the aforesaid parameters are measured by special sensor means, not illustrated in the figures, and are acquired in order to be processed later.

[61] It should be specified that the magnitude indicated with the symbol H in Figures 2, 4 and 6, must therefore be interpreted differently for the first values and the second values. In the case of the first values, the magnitude H refers to the total head which is defined as the difference of the energy possessed by the fluid between the delivery port and the suction port of the pump.

[62] In the case of the second values, the magnitude H refers to the delivery gauge pressure as the operator responsible for verifying the operation of the pumping unit in the system acquires the values measured by pressure sensor means arranged at the delivery of the pumping unit. The use of delivery gauge pressure values is advantageous because they are values acquired directly on the system. This prevents the operator from using further data, for example the system pressure drops, with a consequent decrease in the probability of errors occurring, for example in a data entry step or due to a non-detailed knowledge of the system.

[63] In the disclosure which follows, the use of the term head, with reference to the first values, and the term gauge pressure, with reference to the second values and third values, which will be disclosed below, is to be interpreted according to the respective definitions provided above.

[64] Advantageously, respective curves are defined for both the first values and for the second values, indicated in Figures 2, 3, 4 and 5 as curve 1 for the first values and curve 2 for the second values.

[65] The method further envisages processing, for each curve, a trend line which approximates the respective curve. The values of the coefficients of the polynomial which analytically describes the relative trend line are then obtained for the first values and for the second values. In Figures 2-5 the trend lines associated with respective polynomial equations are indicated as polynomial 1 for the first values and polynomial 2 for the second values.

[66] The next step envisages comparing the first values with the second values and deriving a set of reference values which are congruent with the domain of the first values and the second values, respectively (step c). Domain is intended as a predetermined range of flow rate values in which both the first values and the second values are defined.

[67] In particular, the differences between the first values and the second values are calculated. In the case of head/gauge pressure and flow rate values, the equal flow rate pressure differences between the curve of the first values and the curve of the second values within the domain are calculated. The recorded pressure differences contribute to defining a polynomial 3, not illustrated in the figures, which contains the reference values therein. In particular, the coefficients of the polynomial 3 are calculated as the difference between the coefficients of the polynomial 1 and the coefficients of the polynomial 2. Such reference values are used, in addition to evaluating the energy performance of the pumping unit, also for evaluating the efficiency of the system and/or the pumping unit.

[68] The aforesaid steps allow performing a calibration of the system in which the pumping unit is installed and allow defining the reference values which will be used in the next operative part. In more detail, the second values and the polynomial 2 represent the optimal operation of the pumping unit in the system in which it is inserted and the polynomial 3 allows relating the performance of the pumping unit in the system to the performance of the pumping unit found by the manufacturer in its own test room and therefore interpreting the energy performance in the use phase of the pumping unit.

[69] The method envisages, in a use phase of the pumping unit in the system, continuously acquiring third values related to a pair of pump parameters (step d).

[70] In the case of the third values, the parameters are the gauge pressure and the flow rate, wherein the delivery gauge pressure is measured by pressure sensor means arranged at the pump delivery.

[71] Finally, the method envisages continuously comparing the third values with the second values, verifying how much the performance of the pumping unit in use is deviating from the performance found in the initial verification of the operation of the pumping unit in the system. If the deviation from the second values is greater than a predefined reference value, an operating irregularity is reported (step e). It should be noted that a deviation from the second values may be due to a different operation of the system, to normal wear and tear occurring over time but also to any anomalies occurring in the operation.

[72] The irregularity is reported automatically, for example by means of information displayed on a user interface.

[73] The parameters are measured by special sensor means, as specified below.

[74] The third values related to the gauge pressure and flow rate parameters indicate the working point of the pumping unit which is, therefore, compared with the corresponding second values of the parameters. This allows evaluating the deviation of the working point from the second values.

[75] With reference to Figures 6 and 7, which respectively show the trend of the gauge pressure as the flow rate varies and the power absorbed as the flow rate varies, a working point of the pumping unit (symbol x) is represented, measured at a predetermined instant, together with the polynomial 2 which analytically describes the relative trend line which approximates the curve of the second values. The method envisages calculating the deviation of the working point from the polynomial 2 and assessing whether it is greater than the predetermined reference value.

[76] The method further envisages comparing the third values, i.e., the working point of the pumping unit at a predetermined instant, with predetermined values which define a performance range of the pumping unit. These predetermined values comprise the minimum flow rate Qmin, the maximum flow rate Q_max, the maximum efficiency flow rate of the pumping unit QBEP (Best Efficiency Point), at which the pumping unit works with maximum hydraulic efficiency, the flow rate QPL (Part Load) at which the pumping unit works at 75% with respect to the flow rate measured at maximum hydraulic efficiency, the flow rate QOL (over Load) at which the pumping unit works at 110% with respect to the flow rate measured at maximum hydraulic efficiency. The percentages of 75% and 110% of the maximum efficiency flow rate QBEP identify, for energy saving purposes, an optimal/energetically virtuous field of operation of the pumping unit according to the indications and rules provided by the European Commission and the corresponding American regulatory bodies.

[77] The comparison of the third values, which represent the working point of the pumping unit at a predetermined instant, with these significant values for the performance of the pumping unit, is important to have different types of information, for example information about the energy consumption of the pumping unit, its performance and its correct use. In particular, a pumping unit should always work between the maximum flow rate Qmax and the minimum flow rate Qmin so that reliability problems of the pumping unit itself do not occur.

[78] If the working flow rate of the pumping unit is close to the flow rate QBEP it means that it is working at its maximum efficiency while the flow rates QPL QOL define a range in which the pumping unit should work in order to have an optimal energy consumption.

[79] The method further envisages automatically reporting an anomaly detected following the comparison between the third values and the values defining the performance range of the pump.

[80] If an electric pump controlled by a device to vary the speed of the motor member associated with the pump is installed in a system, the method envisages carrying out steps a and b at a first predetermined frequency and processing the first values and the second values, by means of affinity laws, to obtain corresponding first values and second values at a second frequency different from the first predetermined frequency (step f).

[81] The present invention further relates to a system for evaluating the energy performance of a pumping unit, not illustrated in the figures.

[82] The system comprises sensor means configured to acquire values related to at least one pair of parameters of the pumping unit, comprising the gauge pressure and the flow rate of the pumping unit.

[83] The sensor means comprise at least one flow sensor and at least one pressure sensor. The sensor means can comprise an energy meter. In the case of using an energy meter, in addition to the flow rate and gauge pressure values, the first and second flow rate and power values are also acquired, as already mentioned (see Figures 3, 5 and 7).

[84] The sensor means can comprise a temperature measurement sensor and/or a sensor for measuring the vibratory state of the pump or of the motor member which drives the pump.

[85] The sensor means are arranged in the system in which the pumping unit is installed and are arranged to transmit the measured values of the parameters of the pumping unit to system processing means, preferably by special transmission means. The transmission means can consist of a data acquisition and transmission router.

[86] In the case of using an electric pump, the system can further comprise a control device for varying the speed of the electric motor member adapted to drive the electric pump.

[87] The system comprises the aforesaid processing means which are to perform the abovedescribed steps a-e of the method.

[88] According to an embodiment, the processing means are part of a cloud platform. The platform comprises at least one archive in which the values of the parameters of the pumping unit are stored, in particular the first values, the second values and the third values.

[89] It is possible to envisage that the system comprises a user interface, accessible by an operator in charge of managing the system in which the pumping unit is installed. The user interface can be the interface of an electronic device, for example a computer, a tablet or a smartphone which is in communication with the processing means.

[90] The user interface allows to display, in real time, the third values of the parameters of the pumping unit, in particular the gauge pressure and the flow rate at a predetermined time instant, which represents the working point of the pumping unit, and the trend line related to the second values of the pumping unit (see Figure 6).

[91] The user interface allows displaying, in real time, also further parameters, for example, temperature, current, voltage, power, power factor, current asymmetry, isolation measurement, phase sequence, missing phase and vibratory status of the pump, with the presence of the relative sensor means in the system.

[92] It is further possible to display on the user interface information on the operating hours of the pumping unit and/or on the number of total starts and/or on the number of starts which occurred in a predetermined time interval, preferably in one hour.

[93] The interface can also allow access to previous information of the system, indicating the efficiency status thereof found in the operating period, for each of the magnitudes measured by the sensor means.

[94] The system further comprises an electrical control panel which preferably comprises the power meter.

[95] A further object of the present invention is a computer program comprising instructions which, when the program is run by an electronic computer, cause the electronic computer to carry out steps a-e of the method.

[96] The method which is the subject matter of the present invention achieves the object of optimizing energy consumption, as it envisages continuously comparing the third values, measured at a certain time instant, which give indications on the working point, with the second values or, better, with the trend line which approximates such second values, having a reference value available. Monitoring that the pumping unit operates so as not to exceed the acceptable reference value means monitoring that the pumping unit operates according to a sustainability in terms of energy consumption as well as in a correct manner.

[97] A prerogative of the invention is the fact that the working point of the pumping unit is also compared, continuously, with the flow rates of the pumping unit which define its performance range. It is thereby possible to easily verify whether the pumping unit is working in a range, comprised between QPL and QOL where the energy consumption is optimal. The information is provided to the monitoring operator in an easy manner. Furthermore, it is possible to verify whether the working flow rate is near the maximum performance flow rate QBEP.

[98] It should be noted that the deviation of the working point of the pumping unit with respect to the trend line described by the relative polynomial of the second values provides information on any problems of the pumping unit itself or of the system in which it is installed. If the working point is initially on the polynomial and, over time, distances itself from the polynomial, it can be indicative of a pumping unit malfunction or system problems, for example, wear, leaks, damage to some components, etc.

[99] This continuous monitoring achieves the objective of increasing the life of the pumping unit since it is continuously verified that it has optimal operation, as close as possible to the point of maximum performance. In fact, it must be considered that the fault of the pumping unit often originates in the poor management thereof or if the pumping unit is used for performances which are far from optimal, the operating life of the pumping unit is compromised. Ensuring that the pumping unit works at maximum efficiency means increasing the life of the pumping unit and ensuring that no faults occur if there are no construction defects.

[100] The system described by way of example is susceptible to numerous modifications and variations according to different needs.

[101] In the practical implementation of the invention, the materials employed, as well as the shape and sizes, may be any according to requirements.

[102] Where technical features mentioned in each claim are followed by reference marks, such reference marks have been included for the sole purpose of increasing the understanding of the claims and consequently they do not have any limiting value on the scope of each element identified by way of example by such reference marks.

Claims

1. A method for evaluating the energy performance of a pumping unit implemented by an electronic computer, characterized in that it comprises the following steps: a. acquiring first values related to at least one pair of parameters of said pumping unit, said at least one pair of parameters being measured during a test of said pumping unit, said first values being indicative of an optimal operation of said pumping unit; b. acquiring second values related to at least one pair of parameters of said pumping unit, said at least one pair of parameters being measured during an initial verification of the operation of said pumping unit in the system for which it is intended, said second values being indicative of an initial operation of said pumping unit in the system; c. comparing said first values with said second values and deriving reference values indicative of the difference between said first values and said second values; d. in a use phase of said pumping unit in said system, continuously acquiring third values related to at least one pair of parameters of said pumping unit; e. continuously comparing said third values with said second values and reporting an irregularity if the difference between said third values and said second values is greater than the identified reference value.

2. The method of claim 1 , wherein said steps a. and b. are performed at a preset first frequency and in that it comprises, following said step b. and said step d., the further step f. of processing said first values and said second values, by means of affinity laws, to obtain corresponding first values and second values at a second frequency different from the first predetermined frequency.

3. The method of claim 1 or 2, wherein said parameters comprise the head and flow rate of said pumping unit in the case of said first values, said parameters comprising the gauge pressure and the flow rate in the case of said second values and said third values.

4. The method of claim 3, wherein said parameters comprise one or more of the following parameters: the absorbed power, the temperature, the vibratory state of said pumping unit.

5. The method of any one of the preceding claims, wherein it further envisages comparing said third values with predetermined values defining a performance range of said pumping unit, said predetermined values comprising a minimum flow rate (Qmin), a maximum flow rate (Qmax), a flow rate at which said pumping unit works with maximum hydraulic efficiency (QBEP), a flow rate at which said pumping unit works at 75% with respect to the flow rate measured at maximum hydraulic efficiency (QPL (Part Load)), a flow rate at which said pumping unit works at 110% with respect to the flow rate measured at maximum hydraulic efficiency (QOL (Over Load))-

6. The method of any one of the preceding claims, wherein it comprises the step of defining a curve for said first values and for said second values, respectively.

7. The method of claim 6, wherein it envisages displaying, by means of a user interface, the third values of said parameters of said pumping unit, representing the working point of said pumping unit at a predetermined time instant, and the trend line which approximates the curve of said second values of the pumping unit.

8. The method of claim 6 or 7, wherein it comprises the step of defining a polynomial equation associated with a trend line which approximates said curve respectively for said first values and for said second values.

9. A system for evaluating the energy performance of a pumping unit comprising sensor means configured to measure values related to at least one pair of parameters of said pumping unit; processing means configured to carry out steps a-e of the method according to claim 1 ; transmission means configured to transmit the values measured by said sensor means to said processing means.

10. The system of claim 9, wherein said sensor means comprise at least one flow sensor and at least one pressure sensor.

11. The system of claim 9 or 10, wherein said pumping unit is an electric pump and in that it comprises a control device for varying the speed of a motor member of said electric pump.

12. A computer program comprising instructions which, when the program is run by an electronic computer, cause the electronic computer to carry out steps a-e of the method according to claim 1.