EP4365453A2 - Method for operating an electronically controlled pump unit - Google Patents

Abstract

The method is used to operate an electronically controlled pump unit (1), in which setting parameters of the pump (2) can be set in an electronic control system (6) to adapt to the hydraulic requirements of the local installation situation (4, 5). The operating data are recorded during operation of the pump unit (1). After a predetermined time, the registered operating data is used to check whether the pump unit (1) has been adjusted compared to the factory default settings since commissioning. If this is not the case, a signal (11) is emitted to draw attention to the adjustment that is still required. (Fig. 1)

Description

The invention relates to a method for operating an electronically controlled pump unit with the features specified in the preamble of claim 1 and to an electronic control of an electric motor-driven centrifugal pump unit with the features specified in the preamble of claim 9.

Modern pump units, particularly centrifugal pump units driven by an electric motor, have an electric motor connected to a power converter/frequency converter so that the pumps can be operated in a wide range of speeds and thus cover a comparatively large power spectrum. In circulation pump units, for example, it is state of the art to drive the pump at any constant speed, but also to control operation according to predetermined pump curves. Usually, controls are provided which are operated using hydraulic sensors or, if necessary, only based on the electrical values of the motor. For example, heating circulation pumps can be operated with constant pressure curves, with constant flow curves, with proportional pressure curves or the like. In pressure boosting systems, so-called booster pumps, not only the target delivery pressure has to be set, but also the switching points at which another pump is switched on or off.

This variance made possible by the motor electronics makes it possible to operate a pump unit in an energetically optimized manner for the respective application, but this requires that the pump unit has also been adjusted accordingly in order to be operated in an energetically optimized manner.

In practice, however, the problem often arises that the pump units are installed and put into operation with the factory settings or that the settings are made as a precautionary measure to prevent undersupply. This means that pump units that are actually very energy-efficient run for years with poor efficiency due to inadequate or incorrect setting of the parameters and require more electrical energy than is actually necessary. In addition to the increased energy costs, this often also means that the differential pressure generated by the pump is too high, which can lead to unnecessary leaks in the system and unnecessarily high noise emissions from the pump.

Against this background, the invention is based on the object of designing a method for operating an electronically controlled pump unit in such a way that the above-mentioned problems are avoided as far as possible. In addition, the electronic control of an electric motor-driven centrifugal pump unit is to be adapted to carry out such a method.

The procedural part of this object is achieved by a method having the features specified in claim 1; an electronic control for carrying out the method according to the invention is specified in claim 9.

The method according to the invention for operating an electronically controlled pump unit, in which in an electronic Control system in which the pump setting parameters can be set to adapt to the hydraulic requirements of the local installation situation and in which operating data of the pump unit is recorded during operation, is characterized according to the invention in that after a predetermined time, the recorded operating data is used to check whether the pump unit can be operated in a more energy-efficient range or at least to check whether all setting parameters have not been changed compared to a presetting and then, if it is determined that the pump unit can be operated in a more energy-efficient range or that the setting parameters have not yet been changed compared to the presetting, a signal is emitted to change the setting parameters. The method should preferably be automated, i.e. run automatically, by being implemented in the electronic control system, as described further below.

The basic idea of the invention is to carry out a check after a predetermined time, which either checks on the basis of the operating data recorded within this time interval whether the pump unit can be operated in a more energy-efficient range or, if this check cannot be carried out or does not lead to a clear result, at least checks whether the setting parameters of the pump unit have ever been changed compared to a presetting, in order to then emit a signal on the basis of which it can be recognized that a change in the setting parameters should at least be checked.

In principle, a pump unit within the meaning of the invention can be any electric motor-driven pump with an electronic control system in which the setting parameters of the pump can be adapted to the hydraulic requirements of the local installation situation. are changeable. Typically, these are single- or multi-stage centrifugal pumps controlled by means of a power converter/frequency converter. However, a pump unit in the sense of the invention can also be a number of individual pump units which are operated by a common control system, as is the case with pressure boosting systems (eg booster pumps).

The signal emitted can, for example, be used to control an indicator light provided on the pump unit, to emit an acoustic alarm or to transmit a corresponding data set to a cloud-based database or a server of the manufacturer and/or operator of the pump unit.

The method according to the invention is expediently started with the installation of the pump unit, in which case the factory presetting of the pump unit is the default setting. Then, after a predetermined time, a check is made as to whether this factory presetting has been changed or not and, if there has been no change, the corresponding signal is emitted.

In this respect, it is more advantageous if, after a predetermined time, the registered operating data is used to check whether the pump unit can be operated in a more energy-efficient range. For this purpose, a further development of the method according to the invention provides that, for the energy evaluation of the operating data, electrical operating data of the motor, in particular the electrical power of the motor, which is already available on the control side, and hydraulic operating data of the pump, in particular the pressure and/or flow, are used. This makes it possible to determine the energy behavior of the pump unit without any additional data. to analyze. The hydraulic power resulting from the hydraulic operating data is compared with the electrical power of the motor in order to determine the efficiency of the unit. The power of the electric motor is available from the control electronics, and from the hydraulic data a pressure, typically the differential pressure applied by the pump, is usually available via a sensor, so that the hydraulic power can be determined in conjunction with the speed also available on the motor side. Alternatively or additionally, the data from a flow sensor can be used for this purpose. The hydraulic power is known to be the product of differential pressure, flow rate, the density of the pumped medium and the gravitational acceleration. This data can therefore be used to determine the efficiency of the pump unit at specific times or continuously by evaluating the energy from the operating data.

The operating data are advantageously recorded at intervals or continuously, i.e. recorded and stored, in order to be able to carry out an efficiency test after the predetermined time. It is expedient to carry out such an efficiency test not only from the initial commissioning, but at regular intervals. In order to keep the amount of data to be recorded as small as possible, it is sensible to set limit values, whereby only if these limit values are exceeded or undershot, or the time course of the undershoot or overshoot, is to be recorded. For example, to determine efficiency, it can be specified that the pump unit determines its efficiency, i.e. the ratio between hydraulic power and electrical power, every six minutes. If the limit value has been set at a maximum of 30%, then only the operating points are to be recorded where the efficiency factor is less than 0.7. The total number of operating points to be taken into account is then calculated by dividing the predetermined time by six minutes. The inventive The method can not only be used to force an energy-efficient operation of the pump unit, but can also be used to determine and indicate a significant under- or over-dimensioning of the pump unit.

The method according to the invention can ideally lead to an automatic adjustment of the setting parameters of the pump unit, particularly when the pump unit is connected to the Internet, if not only the transmission and registration of the operating data of the pump unit takes place via an Internet-based network, but also a corresponding adjustment of the setting parameters can be initiated after a network-side check. However, this requires not only a data connection of the pump unit to the Internet-based network, but also the possibility of changing the operating parameters via this network.

For pump units that do not provide for such internet-based setting via a network, a data set with appropriately adjusted setting parameters can be made available for download on the network side, which the service technician can download to his smartphone, for example, and then read into the electronic motor control on site. Ideally, the process in which the efficiency of the pump unit is checked is carried out continuously during the entire operating time. In view of the large amount of data that then has to be recorded and processed, it will be useful in practice to check within a relatively short time after initial commissioning whether the pump unit is running efficiently in terms of energy and then to check this later at longer intervals. In this respect, it is advantageous to choose the predetermined time in which the operating data is recorded between one hour and seven days. Once the pump unit has been put into an energetically efficient mode, more favourable condition and the hydraulic boundary conditions no longer change fundamentally, as is often the case, then it may be sufficient to repeat the energy efficiency test after a certain period of time. Such a period of time is typically between six months and five years, but can also be shorter in individual cases.

The method according to the invention can typically be implemented in existing pump units by means of a software update in the electronic motor control. However, the signal output is then tied to the hardware capabilities of the pump unit. In the simplest form, if the pump unit has no network connection, in particular no internet access, a display, for example a red indicator light or a yellow flashing light, is activated and alternatively or additionally an acoustic signal is emitted so that everyone who is near the pump unit is aware that there is obviously a need for action. If there is a network connection, which is already the case with a large number of pump units, in particular larger ones, then it is advantageous if the signal is transmitted in the form of a data packet via the internet-based network to a server, which informs the manufacturer or the maintenance company that there is a need for action. In this case, it is advantageous if the data packet contains the location data of the pump unit, as spatial assignment is then possible without access to other personal databases.

The electronic control of an electric motor-driven centrifugal pump unit according to the invention is used to carry out the method according to the invention. It has means for setting setting parameters to adapt the pump unit to the hydraulic requirements of the local installation situation. These can by buttons/switches/touch screens on the unit itself, with which the setting parameters can be changed, for example by selecting corresponding control curves or pressure/flow setpoints. However, such means can also be formed wirelessly, for example by means of a mobile computer, typically smartphones or tablets, on which a corresponding software application runs with which this data can be entered and transmitted wirelessly to the electronic control system. If the electronic control system is connected to a network, these means can also be formed by transmitting corresponding settings over the network.

The control itself is designed to register or forward operating data of the pump unit. Depending on the available storage and computing capacity, the method according to the invention, including registration and evaluation of the registered data, can be carried out within the electronic control of the pump unit or at least partially via a network-connected server with which the electronic control is in data connection.

According to the invention, the electronic control of the pump unit is designed to determine itself whether a setting of the setting parameters has been made after a predetermined time compared to a registered setting and to automatically emit a signal if the setting has not been made. In principle, such a check can be carried out automatically by the control at regular intervals or even continuously. However, it is particularly advantageous if this predetermined time begins when the control is put into operation and the registered setting is the factory setting. This ensures that when the pump unit is installed at its destination after delivery by the manufacturer and connected to the electrical supply network, immediately after During this initial commissioning, it is at least monitored whether the setting parameters have been changed compared to the factory settings or not. If this is not the case and the signal requesting the setting parameters to be adjusted is given, it can be assumed with a high degree of probability that the pump unit is running in an energy-optimized range, since no setting of the setting parameters has been made after installation and commissioning.

In an advantageous further development, however, the electronic control is further designed to automatically determine whether the pump unit is being operated in an energy-efficient range or not. The storage and computing operations required in this regard are more complex, however, which is why they can advantageously also be carried out externally via a network. For this purpose, as well as for transmitting the signal and/or operating data, the control advantageously has an interface to a network, preferably to an internet-based network. Such an interface can be wired, for example as a LAN connection, but is particularly advantageously designed for wireless data transmission, for example via WLAN or a mobile phone connection.

Since pump units are often located in areas not covered by wireless networks - whether underground or in basements - it can be advantageous according to a further development of the invention to design the electronic control in such a way that it is provided for transmitting the setting parameters using a software application of a mobile input device, in particular a smartphone. The mobile input device can establish the connection to the network, which may not have to happen at the same time. The setting parameters to be transmitted are then advantageously taken from the network using of the mobile input device and subsequently transferred to the electronic control system.

In order to be able to implement the method according to the invention with the least possible hardware outlay in an electronic control system, a further development of the invention provides that the setting parameters are stored in a file in the control system and that only the change in this file is monitored. A file in the sense of this invention can also be a group of files or a folder; the crucial point is that the monitoring can take place without specifically monitoring the setting parameters themselves, but simply by monitoring the file, which, when changed, has a changed date or another identifier.

The setting parameters of the electronic control are advantageously one or more of the control variables such as flow rate, delivery pressure, speed, power, whereby the hydraulic control variables flow rate and/or delivery pressure can typically be set in the form of control curves.

Fig. 1

in schematischer Darstellung eine cloudbasierte Einbindung einer elektronischen Motorsteuerung eines Pumpenaggregates,

Fig. 2A bis C

drei Diagramme mit Pumpenkurven und

Fig. 3

ein Ablaufdiagramm.

The invention is explained in more detail below with reference to embodiments shown in the drawings.

Fig.1

a schematic representation of a cloud-based integration of an electronic motor control of a pump unit,

Fig. 2A to C

three diagrams with pump curves and

Fig.3

a flow chart.

In Fig.1 a pump unit 1 is shown, a so-called booster pump, which is made up of three centrifugal pumps 2 connected in parallel, each of which is driven by a frequency converter-controlled electric motor 3, which pumps from a common suction line 4 into a common pressure line 5. The pump unit 1 has a higher-level electronic control 6, into which setting parameters, in particular the delivery pressure and the switching on and off points of the individual pumps, can be entered. This electronic control has an interface to a network that is cloud-based. The control 6 is equipped with a WLAN module and a mobile radio module, via which it is wirelessly connected to the network of the pump manufacturer 7 via the Internet 8, i.e. the "cloud". The electronic control is also equipped with a Bluetooth interface, via which it can communicate with a smartphone 9, via which an operator 10 can query and change the setting parameters available in the control 6. The smartphone 9 is also connected to the Internet 8 and thus to the network of the manufacturer 7 via its radio interface.

The electronic control 6 is designed to check after a predetermined time after the pump unit 1 has started operating whether the setting parameters have been changed compared to the factory settings. These parameters are digitally stored in a file in the control 6, and the control 6 monitors the storage date of the file. From the initial start-up, a timer runs, which is set to 72 hours, for example, so that after this predetermined time has elapsed, a check is made to see whether the storage date of the file has changed or not. If this is not the case, a signal is emitted, namely on the control 6 itself to activate a warning light 11, which emits a flashing signal as a sign that the pump unit 1 has not yet been set. At the same time, a corresponding data signal is emitted to the network, so that the database of the Manufacturer 7, specifying the GPS data of the location of the pump unit, this is noted and at the same time a message appears that this pump unit must be set up by a service technician. Depending on the design and connection to the network, this required setting can be made via the network itself or via the manufacturer 7 or operator. In the embodiment shown, a service technician is required, i.e. an operator 10 who goes to the pump unit 1 with his smartphone 9 and a software application running on it in order to adjust the setting parameters in the controller 6 accordingly via his smartphone 9. The service technician 10 receives not only the message via the network 8 that the pump unit 1 must be configured with regard to its setting parameters, but also the location data and, if available, the data that can be downloaded from the network 8 for adjusting the setting parameters.

In addition to this device for monitoring the setting of the setting parameters, the electronic control 6 has a further function with which the operating points are recorded at intervals of three minutes during operation of the pump unit and these are evaluated with regard to their energy efficiency, as can be seen from the Fig. 2A to C as explained below:

The Fig. 2A shows a typical pump curve of a pump unit, where the delivery head is plotted as a function of the delivery rate. The delivery head is the differential pressure between the pump inlet and pump outlet, the delivery rate is the volume flow per unit of time. The Fig. 2A The pump curve shown schematically represents a centrifugal pump at a constant speed. The Fig. 2B shows the electrical power P of this pump unit as a function of the flow rate.

When using a power converter/frequency converter with electronic control 6, the pump unit can be operated on a variety of different pump curves according to Fig. 2A and 2B driven, as shown by Fig. 2C , which shows three such curves ω1, ω2 and ω 3, which represent different speeds. These curves represent the efficiency η as a function of the flow rate at a speed. The efficiency is the quotient of hydraulic power and electrical power, ideally one. The electrical power is determined by the input power, i.e. the product of current and voltage of the driving electric motor or motors, and is available in the form of data in the control unit 6. The hydraulic power results from the product of flow rate, head, density and gravitational acceleration. It can be calculated using differential pressure and flow sensors. In the absence of a flow rate signal, the calculation is often only carried out on the basis of the differential pressure signal. As the three curves ω1, ω2 and ω3 of the Fig. 2C To illustrate, there is only one point of highest effectiveness (BEP) at each speed [BEP stands for Best Efficiency Point].

These efficiency calculations are carried out and stored in the electronic control system 6 at intervals of, for example, three minutes. The corresponding operating points are in Fig. 2C exemplified by crosses.

After a predetermined time, the electronic control system checks the efficiency at the pump's operating points using the previously determined effectiveness curves, which are either determined during operation or are specifically approached. It can now be determined using the operating points and temporal correlation whether they are in the BEP range or outside it. A limit value of 30%, for example, is used as a basis, so that only It is considered how many of the operating points are outside this 30% limit and how many are inside. Those outside this limit are in Fig. 2C shown in group M.

The electronic control 6 is thus able to check whether the pump unit can be operated in a more energy-efficient range by changing the setting parameters. If this is the case, the control 6 sends a corresponding signal to the network so that the manufacturer or operator is prompted to change the setting parameters.

The setting parameters suitable for the pump unit can be specified by the manufacturer and transmitted wirelessly via the network to the smartphone 9 of the operator 10, who then transmits them to the electronic control 6 of the pump unit 1, or they can be selected and set by the operator himself.

In Fig. 2C the operating points are shown in a range M that lies outside the 30% of the BEPs. It is therefore shown that eight of the ten operating points lie outside the 30% range and thus 80% of the operating points fall below the specified efficiency limit range. In this case, an adjustment of the setting parameters is required.

Based on Fig.3 the process flow is shown. In a first step 15, the efficiency curves of the pump unit are generated. These can either be targeted or determined during operation for different flow rates depending on the speed, which is always known on the motor side and thus on the control side. Since the curves are never complete, either the pump unit can be controlled to run the entire curve or interpolated. In practice, it is sufficient to determine the BEPs that result for each speed. Once this data has been collected, the efficiency test of the pump can be carried out during operation. It goes without saying that these procedures can initially overlap in time, but this is not a problem.

If the efficiency monitoring is to be run again after a time interval of, for example, six months or one or two years after the pump has been put into operation and the first check, it starts in step 16 after the timer has expired according to the set time of six months, one or two years after the first check of the pump unit.

The efficiency of the current operating point of the pump unit is now calculated and saved at a predetermined time interval, for example every ten minutes. After a predetermined time of, for example, 48 hours, this calculation and saving of the efficiency in the operating points is terminated in the third step 17. In the fourth step 18, the distribution of the operating points is then evaluated on the control side with regard to their efficiency in relation to the BEP. If a predetermined percentage of the operating points, for example more than 60% of the operating points, fall below the BEP by more than 30%, a signal is emitted in the fifth step 19, depending on the evaluation result, to change the setting parameters or to replace the pump with a smaller or larger one.

If the control system determines that the operating points are within the previously defined 30% limit in terms of their efficiency, the process may only be restarted after a predetermined time interval has elapsed, so that the pump unit is monitored for efficiency virtually throughout its entire operating life. If the setting parameters are changed after the signal is given in the fifth step 19, the process is also resumed in the second step 16, whereas if the pump is replaced, the process starts again with the first step 15.

List of reference symbols

1

Pump unit

2

Centrifugal pump

3

Electric motor

4

Suction line

5

Pressure line

6

electronic control

7

Manufacturer/Operator

8th

Internet/Cloud

9

smartphones

10

operator

11

Warning light

15

First step (determining the efficiency curves for different speeds)

16

second step (starting the program and starting the timer six months, one, two years)

17

third step (saving and determining the efficiency of operating points)

18

fourth step (evaluation of the determined efficiency values)

19

fifth step (signal delivery)

Claims (13)

Method for operating an electronically controlled pump unit, in which setting parameters of the pump can be set in an electronic control system to adapt to the hydraulic requirements of the local installation situation, and in which operating data of the pump unit are registered during operation, characterized in that after a predetermined time, the registered operating data are used to check whether the pump unit can be operated in a more energy-efficient range, and then, if this is determined, a signal is emitted to change the setting parameters. Method according to claim 1, characterized in that for the energetic evaluation of the operating data, electrical operating data of the motor, in particular the electrical power of the motor, and hydraulic operating data of the pump, in particular pressure and/or flow, are used. Method according to claim 1 or 2, characterized in that the registration of operating data and the checking are repeated after the predetermined time or a time interval after the checking has taken place. Method according to one of the preceding claims, characterized in that after the predetermined time, a further check is carried out on the basis of the registered operating data as to whether one or more predetermined, preferably temporally correlated, operating data limit values have been exceeded and, if this is determined, a signal is emitted to change the setting parameters. Method according to one of the preceding claims, characterized in that the operating data of the pump unit are registered via an internet-based network and after the predetermined time it is checked on the network side whether the pump unit can be operated in a more energy-efficient range in order to then preferably adapt or maintain the setting parameters accordingly on the network side or to make the setting parameters available for adoption. Method according to one of the preceding claims, characterized in that the predetermined time is between one hour and seven days and/or the time interval is between 1 and 5 years. Method according to one of the preceding claims, characterized in that the signal activates a visual display and/or acoustic signal or is transmitted via the internet-based network, preferably together with the location data of the pump unit. Electronic control (6) of an electric motor-driven centrifugal pump unit (1), in particular for carrying out the method according to one of the preceding claims, with means for setting setting parameters for adapting the pump unit (1) to the hydraulic requirements of the local installation situation (4, 5), wherein the control (6) is designed to register and/or forward operating data, characterized in that the control (6) is further designed to automatically determine whether the pump unit is operated in an energetically favorable range or not. Electronic control according to claim 8, characterized in that the control (6) has an interface to a preferably internet-based network (8), via which the signal and/or the operating data can be forwarded. Electronic control according to claim 8 or 9, characterized in that the control (6) has an interface for wireless data transmission. Electronic control according to one of the preceding claims 8 to 10, characterized in that the control (6) is designed for wireless transmission of the setting parameters by means of a software application of a mobile input device, in particular a smartphone (9) and/or for transmission from the network (8). Electronic control according to one of the preceding claims 8 to 11, characterized in that the setting parameters are stored digitally in a file of the control (6) and that the change in this file is monitored. Electronic control according to one of the preceding claims 8 to 12, characterized in that the setting parameters are one or more of the controlled variables delivery rate, delivery pressure, speed, power, wherein delivery rate and/or delivery pressure are preferably adjustable in the form of control curves.

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