IT202300024801A1 - METHOD AND SYSTEM FOR EVALUATION OF THE ENERGY PERFORMANCE OF A PUMPING UNIT - Google Patents

Description

Description

METHOD AND SYSTEM FOR PERFORMANCE EVALUATION

ENERGY OF A PUMPING GROUP

Technical field

The present invention relates to a method and a system for evaluating the energy performance of a pumping unit, wherein the pumping unit comprises a pump and an actuator suitable for driving the pump into motion.

Known art

The need to monitor the operation of pumps, especially electric pumps, in the systems in which they are used has long been recognized in order to prevent malfunctions and prevent system shutdowns. Malfunctions can be due to various factors, such as, for example, construction defects in an electric pump component or system-related problems (leaks in the pipes, changes in the dynamic level of the well over time, etc.).

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

International application WO2020253926 describes a computer-implemented system for controlling and monitoring a pump system. The system includes at least one pump, a sensor capable of providing signals representative of the pump's operating state from a mechanical, fluid, and electrical perspective, and a control module designed to control the pump's state in response to the received signals. The system also includes a digital module comprising an API for processing data and a repository in which the digital module receives signals indicative of the pump's operating state and stores the data in the repository. The digital module communicates with a chatbot agent that is configured to communicate with the API and a user. The chatbot agent, upon request from the user, provides information on the current or historical state of the pump using the digital module's API, extracting information from the repository, and transmits a control signal to the pump system to set the pump to a required operating state. The chatbot agent assists the user in identifying the correct control parameter to send a control signal to the pump system that changes its operating state. The digital module can be used to predict future pump operation based on archived data or sensor data, and the prediction is made using machine learning algorithms or artificial intelligence.

A further example of a method for monitoring an electric pump is illustrated in international application WO2023/020998. The method aims to detect a fault in a centrifugal pump, in particular a blockage of the impeller, and involves 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 the drive motor influences certain frequencies in the current spectrum. The method is implemented in a data processing unit of the pump or in an external data processing unit. Also described is a system comprising a pump that implements the aforementioned method to calculate a damage factor and transmit it, via a gateway, to an external cloud-based unit.

The solutions developed to monitor a pump are primarily aimed at verifying whether there are pump failures but have not been specifically designed to reduce energy consumption.

The issue of energy efficiency in the industrial sector is of significant importance, which has become even greater in recent years, and there is a keenly felt need to devise new pump monitoring solutions that allow energy consumption to be minimized.

Presentation of the invention

The aim of the present invention is to solve the aforementioned problems by devising a method for evaluating the energy performance of a pumping unit that allows for the optimization of energy consumption related to the management of the system in which the unit is installed.

Within the scope of this task, a further aim of the present invention is to provide a method for evaluating the energy performance of a pumping unit that provides direct and easily understandable information to monitoring operators regarding any corrective actions to be taken to reduce energy consumption.

A further object of the present invention is to devise a method for evaluating the energy performance of a pumping unit which allows for an increase in the operating life of the pumping unit.

Another object of the invention is to provide a method that allows for the identification of any malfunctions of the pumping unit.

The aforementioned 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 8, as well as by the computer program according to claim 11.

The method for evaluating the energy performance of a pumping unit implemented by an electronic computer comprises the phase of acquiring first values relating 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 optimal operation of said pumping unit.

The method then includes the phase of acquiring second values relating to at least one pair of parameters of said pumping unit, said at least one pair of parameters being measured during an initial check 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.

The method then involves comparing the first values with the second values and obtaining reference values indicative of the difference between the first values and the second values.

In a phase of use of said pumping group in said plant, the method provides for continuously acquiring third values relating to at least one pair of parameters of said pumping group.

Finally, the method includes 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.

The method allows for energy consumption optimization as it involves continuously comparing the third values, which provide information on the pumping unit's operating point, and the second values, having a reference value that must not be exceeded.

Preferably, the parameters include, in the case of said first values, the head and flow rate of said pumping group.

Preferably, in the case of said second and third values, the parameters include the manometric pressure and the flow rate. It should be noted that the manometric pressure is the pressure measured by sensors located at the pumping unit's delivery port and is advantageous because these values are acquired directly from the system. This way, the operator does not need to use additional data, such as, for example, the system's pressure drops, reducing the possibility of errors occurring during data entry or due to incomplete knowledge of the system.

Preferably, the parameters also include one or more of the following parameters: the absorbed power, the temperature, the vibration state of said pumping unit.

Advantageously, if an electric pump controlled by a device is used to vary the speed of the motor associated with the pump, the method involves performing the phases of acquiring the first values and acquiring the second values at a first predetermined frequency and also includes the phase of processing the first values and the second values, using the affinity laws, to obtain corresponding first values and second values at a second frequency different from the first predetermined frequency.

Advantageously, the method also provides for comparing said third values with predetermined values that define a performance range of said pumping group, said predetermined values including a minimum flow rate (Qmin), a maximum flow rate (Qmax), a flow rate at which said pumping group operates at maximum hydraulic efficiency (QBEP), a flow rate at which said pumping group operates at 75% of the flow rate measured at maximum hydraulic efficiency (QPL).

(Part Load)), a flow rate at which the pumping unit operates at 110% of the flow rate measured at maximum hydraulic efficiency (QOL(Over Load)).

This step allows you to easily check whether the pumping unit is operating within the optimal energy consumption range between QPL and QOL. Furthermore, you can check whether the pumping unit's operating flow rate is close to the maximum efficiency flow rate QBEP.

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

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

The present invention also relates to a system for evaluating the energy performance of a pumping unit comprising sensor means configured to measure values relating to at least a pair of parameters of said pumping unit.

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

Preferably, the system comprises said processing means which are configured to perform the aforementioned phases of the method, in particular the phases of acquiring the first values and the second values, comparing the first values with the second values and obtaining reference values indicative of the difference between the first and second values, continuously acquiring, in a phase of use of the pumping unit, third values relating to at least one pair of parameters and continuously comparing said third values with the second values, signaling an irregularity if the difference is greater than the identified reference value.

Preferably, the processing means are included in a cloud platform. Preferably, the sensor means comprise at least one flow sensor and at least one pressure sensor.

The sensor means may also include a temperature measurement sensor and/or a sensor for measuring the vibration state of the pump or the motor part that drives the pump.

If an electric pump is used, the system may also include a control device to vary the speed of the electric motor used to operate the electric pump.

Preferably, the system includes a user interface, accessible by an operator responsible for managing the system in which the pumping unit is installed. The user interface may be the interface of an electronic device such as a computer, tablet, or smartphone that communicates with the processing equipment.

Preferably, the user interface allows the third values of the pumping unit parameters to be displayed in real time, in particular the manometric pressure and the flow rate at a predetermined instant in time, which represents the operating point of the pumping unit, and the trend line relating to the second values of the pumping unit.

The present invention also relates to a computer program comprising instructions which, when the program is executed by an electronic computer, cause the electronic computer to perform the following steps of the method: acquiring the first values and the second values; comparing the first values with the second values and obtaining reference values indicative of the difference between the first and second values; continuously acquiring, during a phase of use of the pumping unit, third values relating to at least one pair of parameters and continuously comparing said third values with the second values, signaling an irregularity if the difference is greater than the identified reference value.

Brief description of the drawings

The details of the invention will become more evident 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 attached drawings, in which:

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

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

Figure 4 shows two curves relating to the head/manometer pressure of a pumping unit as a function of the flow rate, obtained in 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 relating 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 relating to the manometric 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 relating 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. Embodiments of the invention

With particular reference to these figures, the block diagram 1 indicates the steps of the method for evaluating the energy performance of a pumping unit according to the present invention.

The term pumping unit refers to a unit comprising a pump and an actuator, where the actuator is designed to drive the pump. The actuator may be, for example, an internal combustion engine, a hydraulic motor, or an electric motor.

The method is preferably used to monitor and manage an electric pump, i.e., a pumping unit comprising a pump and an electric motor that drives the pump. The method can obviously also be implemented for a different type of pumping unit.

In the following description, the term electric pump will be used to refer to a pumping unit comprising an electric motor and a pump.

The method for evaluating the energy performance of a pumping unit is implemented using an electronic computer.

The method first involves acquiring initial values for at least one pair of pump unit parameters, in which the parameters are measured during a pump unit test (phase a). The test is preferably carried out in the pump manufacturer's testing facility. It is good practice to conduct this test using the procedure according to UNI EN ISO 9906.

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

The first values are made available by the manufacturer to the customer and relate to the pumping unit that the customer has selected based on the needs of their system.

Subsequently, the method involves acquiring second values relating to at least one pair of parameters of the pumping unit, in which the parameters are measured during an initial check of the unit's operation in the system for which it is intended. In practice, the pumping unit is installed in the system in which it will be used and a check of its operation is performed by measuring the aforementioned second values (phase b), which are indicated by the circle and triangle symbols in Figures 2 and 3, respectively.

The second values allow us to verify how the system and the pumping unit interact and influence each other, therefore, they allow us to evaluate the influences of the system on the pumping unit.

The parameters include, in the case of the first values, the head (indicated by H in figures 2 and 4) and the flow rate (indicated by Q in figures 2-7). The parameters, in the case of the second values, include the manometric pressure measured at the pumping unit's delivery (indicated by H in figures 2, 4, and 6) and the flow rate (indicated by Q in figures 2-7). In the case of an electric pump, the parameters may also include the power (indicated by P in figures 3, 5, and 7) absorbed as the flow rate varies. The values of the aforementioned parameters are measured using special sensors, not shown in the figures, and are acquired for subsequent processing.

Please note that the quantity indicated by the symbol H in figures 2, 4, and 6 must therefore be interpreted differently for the first and second values. In the case of the first values, the quantity H refers to the total head, which is defined as the difference in energy possessed by the fluid between the delivery port and the suction port of the pump.

In the case of the second values, the quantity H refers to the delivery manometric pressure since the operator in charge of checking the operation of the pumping unit in the system acquires the values measured by pressure sensors positioned at the delivery of the pumping unit. The use of delivery manometric pressure values is advantageous because they are values acquired directly on the system. This prevents the operator from using additional data, such as, for example, the system's pressure drops, with a consequent reduction in the probability of errors occurring, for example during data entry or due to incomplete knowledge of the system.

In the following description, the use of the term head, with reference to the first values, and of the term manometric pressure, with reference to the second and third values, which will be described below, is to be interpreted according to the respective definitions provided above.

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

The method also involves developing, for each curve, a trend line that approximates the respective curve. The coefficient values of the polynomial that analytically describes the respective trend line are then obtained for the first and 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.

The next step involves comparing the first values with the second values and obtaining a set of reference values that are consistent with the domain of the first and second values, respectively (step c). A domain is a predetermined range of flow rates within which both the first and second values are defined.

Specifically, the differences between the first and second values are calculated. For head/manometer pressure and flow rate values, the pressure differences are calculated for the same flow rate between the curve of the first values and the curve of the second values within the domain. The recorded pressure differences contribute to defining a polynomial 3, not shown in the figures, which contains the reference values. Specifically, the coefficients of polynomial 3 are calculated as the difference between the coefficients of polynomial 1 and the coefficients of polynomial 2. These reference values are used not only to evaluate the energy performance of the pumping unit, but also to evaluate the efficiency of the system and/or pumping unit.

The aforementioned steps allow for calibration of the system in which the pumping unit is installed and allow for the definition of the reference values that will be used in the subsequent operational phase. More specifically, the second values and polynomial 2 represent the optimal operation of the pumping unit in the system in which it is inserted, and polynomial 3 allows for the performance of the pumping unit in the system to be compared to the performance of the pumping unit found by the manufacturer in its own test room and therefore for an energetic interpretation of the performance during the use phase of the pumping unit.

The method involves, in a phase of use of the pumping unit in the system, continuously acquiring third values relating to a pair of pump parameters (phase d).

In the case of the third values, the parameters are the gauge pressure and the flow rate, where the gauge pressure at the delivery end is measured by pressure sensors arranged at the pump delivery end.

Finally, the method involves 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 observed during the initial check of the pumping unit's operation in the system. If the deviation from the second values is greater than a predefined reference value, an operating irregularity is reported (phase e). It is noted that a deviation from the second values may be due to different system operation, normal wear and tear over time, or even any operational anomalies.

Irregularities are reported automatically, for example through information displayed on a user interface.

The parameters are measured by special sensors, as specified below.

The third values for the manometric pressure and flow rate parameters indicate the pumping unit's operating point, which is then compared with the corresponding second parameter values. This allows us to evaluate the operating point's deviation from the second values.

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

The method also involves comparing the third values, i.e. the operating point of the pumping unit at a predetermined time, with predetermined values that define a performance range of the pumping unit. These predetermined values include the minimum flow rate Qmin, the maximum flow rate Qmax, and the maximum efficiency flow rate of the pumping unit QBEP (Best Efficiency).

Point), at which the pumping unit operates at maximum hydraulic efficiency, the QPL (Part Load) flow rate at which the pumping unit operates at 75% of the flow rate measured at maximum hydraulic efficiency, and the QOL (Over Load) flow rate at which the pumping unit operates at 110% of the flow rate measured at maximum hydraulic efficiency. The percentages of 75% and 110% of the flow rate at maximum efficiency QBEP identify, for energy saving purposes, an optimal/energetically virtuous range of operation for the pumping unit according to the indications and rules provided by the European Commission and the corresponding American regulatory bodies.

Comparing the third values, which represent the pumping unit's operating point at a predetermined time, with these values, which are significant for the pumping unit's performance, is important to obtain various types of information, such as information regarding the pumping unit's energy consumption, performance, and proper use. In particular, a pumping unit should always operate between the maximum flow rate Qmax and the minimum flow rate Qmin to avoid reliability problems with the pumping unit itself.

If the pumping unit's operating flow rate is close to the QBEP flow rate, it means that it is working at its maximum efficiency, while the QPL and QOL flow rates define a range in which the pumping unit should work to have optimal energy consumption.

The method also provides for automatic reporting if an anomaly is detected following the comparison between the third values and the values that define the pump's performance range.

In the case where an electric pump controlled by a device for varying the speed of the motor associated with the pump is installed in a system, the method involves executing phases a and b at a first predetermined frequency and processing the first values and the second values, using the affinity laws, to obtain corresponding first values and second values at a second frequency different from the first predetermined frequency (phase f).

The present invention also relates to a system for evaluating the energy performance of a pumping unit, not illustrated in the figures. The system comprises sensor means configured to acquire values relating to at least one pair of parameters of the pumping unit, including the manometric pressure and the flow rate of the pumping unit.

The sensor means comprise at least one flow sensor and at least one pressure sensor. The sensor means may comprise a power meter (energy meter). When using a power meter, in addition to the flow rate and manometric pressure values, primary and secondary flow rate and power values are also acquired, as previously mentioned (see Figures 3, 5, and 7). The sensor means may comprise a temperature sensor and/or a sensor for measuring the vibration state of the pump or the motor that drives the pump.

The sensor devices are located in the system where the pumping unit is installed and are designed to transmit the measured values of the pumping unit parameters to the system's processing devices, preferably via dedicated transmission devices. The transmission devices may consist of a data acquisition and transmission router.

If an electric pump is used, the system may also include a control device to vary the speed of the electric motor used to operate the electric pump.

The system comprises the aforementioned processing means which are configured to perform the steps a-e described above of the method.

According to one embodiment, the processing means are part of a cloud platform. The platform includes at least one archive in which the pump unit parameter values are stored, specifically the first values, the second values, and the third values.

The system may include a user interface, accessible by an operator responsible for managing the system in which the pumping unit is installed. The user interface may be the interface of an electronic device such as a computer, tablet, or smartphone that communicates with the processing equipment.

The user interface allows you to view, in real time, the third values of the pumping group parameters, in particular the manometric pressure and the flow rate at a predetermined instant in time, which represents the operating point of the pumping group, and the trend line relating to the second values of the pumping group (see figure 6).

The user interface also allows for real-time viewing of additional parameters such as temperature, current, voltage, power, and pump vibration status, provided the relevant sensors are present in the system. The interface can also provide access to previous system information, which indicates the system's efficiency status during the operating period, for each of the parameters measured by the sensors.

The system also includes an electrical control panel which preferably includes the power meter.

A further object of the present invention is a computer program comprising instructions that, when the program is executed by a computer, cause the computer to execute steps a-e of the method. The method of the present invention achieves the goal of optimizing energy consumption by continuously comparing the third values, measured at a specific point in time, which provide indications of the operating point, with the second values, or rather, with the trend line that approximates these 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 sustainably in terms of energy consumption as well as correctly.

A prerogative of the invention is the fact that the pumping unit's operating point is also continuously compared with the pumping unit's flow rates, which define its performance range. In this way, it is possible to easily verify whether the pumping unit is operating within an optimal energy consumption range between QPL and QOL. The information is made easily available to the monitoring operator. Furthermore, it is possible to verify whether the operating flow rate is close to the maximum efficiency flow rate QBEP.

It is noted that the deviation of the pumping unit's operating point from the trend line described by the corresponding polynomial of the second values provides information on any problems with the pumping unit itself or the system in which it is installed. If the operating point initially lies on the polynomial and, over time, distances itself from the polynomial, it may indicate a malfunction of the pumping unit or problems with the system such as, for example, wear, leaks, damage to some components, etc.

This continuous monitoring achieves the goal of increasing the life of the pumping unit by continuously verifying that it is operating optimally, as close as possible to its maximum efficiency point. It must be considered that pumping unit failure often arises from poor management. If the pumping unit is used for performance levels that are far from optimal, the operating life of the pumping unit is compromised. Ensuring that the pumping unit operates at maximum efficiency means increasing its life and ensuring that failures do not occur unless there are construction defects.

The system described as an example is susceptible to numerous modifications and variations depending on different needs.

In the practical implementation of the invention, the materials used, as well as the shape and dimensions, can be any according to the needs.

Where the technical features mentioned in each claim are followed by reference signs, such reference signs have been included for the sole purpose of enhancing the understanding of the claims and consequently they have no limiting value on the purpose of each element identified by way of example by such reference signs.

Claims (11)

Claims 1) Method for the evaluation of the energy performance of a pumping unit implemented by an electronic computer characterised by the fact that it includes the following phases: a. acquire first values relating to at least one pair of parameters of said pumping group, said at least one pair of parameters being measured during a test of said pumping group, said first values being indicative of optimal functioning of said pumping group; b. acquire second values relating to at least one pair of parameters of said pumping unit, said at least one pair of parameters being measured during an initial check 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. compare said first values with said second values and obtain reference values indicative of the difference between said first values and said second values; d. in a phase of use of said pumping group in said plant, continuously acquire third values relating to at least one pair of parameters of said pumping group; e. continuously compare said third values with said second values and report an irregularity if the difference between said third values and said second values is greater than the identified reference value. 2) Method according to claim 2, characterized in that said phases a. and b. are performed at a predetermined first frequency and in that it comprises, following said phase b. and said phase d., the further phase f. of processing said first values and said second values, by means of the affinity laws, to obtain corresponding first values and second values at a second frequency different from the first predetermined frequency. 3) Method according to claim 1 or 2, characterized in that said parameters include the head and the flow rate of said pumping group in the case of said first values, said parameters including the manometric pressure and the flow rate in the case of said second values and said third values. 4) Method according to claim 3, characterized in that said parameters include one or more of the following parameters: the absorbed power, the temperature, the vibratory state of said pumping group. 5) Method according to one of the preceding claims, characterized in that it also provides for comparing said third values with predetermined values that define 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 operates at maximum hydraulic efficiency (QBEP), a flow rate at which said pumping unit operates at 75% of the flow rate measured at maximum hydraulic efficiency (QPL (Part Load)), a flow rate at which said pumping unit operates at 110% of the flow rate measured at maximum hydraulic efficiency (QOL (Over Load)). 6) Method according to one of the preceding claims, characterized in that it comprises the step of defining a curve for said first values and for said second values respectively. 7) Method according to claim 6, characterized in that it comprises the step of defining a polynomial equation associated with a trend line that approximates said curve for said first values and said second values respectively. 8) System for the evaluation of the energy performance of a pumping group comprising sensor means configured to measure values relating to at least one pair of parameters of said pumping group; processing means configured to perform 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. 9) System according to claim 8, characterized in that said sensor means comprise at least one flow sensor and at least one pressure sensor. 10) System according to claim 8 or 9 characterised in that said pumping unit is an electric pump and in that it comprises a control device for varying the speed of a motor part of said electric pump. 11) A computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform steps a-e of the method according to claim 1.