Monitoring method for a turbopump

Abstract

The invention relates to a method for monitoring the functionality and / or state of a centrifugal pump (1), comprising the steps of: during operation (20) of the centrifugal pump (1) in a reference operating mode, acquiring (30) at least one operating parameter of the centrifugal pump (1), evaluating (40) the at least one operating parameter to obtain information about the functionality and / or state of the centrifugal pump (1), and operating (10, 70) the centrifugal pump (1) in a normal operating mode before and / or after operation (20) of the centrifugal pump (1) in the reference operating mode, wherein the centrifugal pump (1) is operated in the reference operating mode at least for a predefined period at a maximum speed stage.

Description

Technical area

[0001] The invention relates to a method for monitoring a centrifugal pump. The invention also relates to a centrifugal pump. Background of the invention

[0002] Centrifugal pumps are known in the art and are used to pump a fluid by means of the rotary motion of an impeller provided within the centrifugal pump. The impeller is driven by a motor in the centrifugal pump via a rotor shaft. Such centrifugal pumps are controlled by a controller.

[0003] Monitoring such a centrifugal pump is essential in practice to ensure that the required performance is achieved. Solutions are being sought to improve centrifugal pump monitoring. Description of the invention

[0004] Based on this situation, the present invention aims to provide solutions that enable a centrifugal pump to be monitored cost-effectively and with the shortest possible downtime. In particular, solutions are to be provided that avoid or at least significantly reduce the disadvantages of the prior art.

[0005] The object of the invention is achieved by the features of the independent claims. Advantageous embodiments are specified in the subclaims, the description, and the drawings.

[0006] Accordingly, the problem is solved by a method for monitoring the functionality and / or condition of a centrifugal pump. The proposed method comprises the following steps: during operation of the centrifugal pump in a reference operating mode, detecting at least one operating parameter of the centrifugal pump, evaluating the at least one operating parameter to obtain information about the functionality and / or the state of the centrifugal pump, and operating the centrifugal pump in a normal operating mode before and / or after operating the centrifugal pump in the reference operating mode, wherein the centrifugal pump is operated at a maximum speed level in the reference operating mode at least for a predefined period of time.

[0007] In other words, a method is proposed in particular in which a centrifugal pump is placed into a monitoring state by running the centrifugal pump at its maximum speed for a certain period of time, in particular temporarily, after and / or before the centrifugal pump has been / is being operated in its normal state. While the monitoring state exists, one or more so-called operating parameters of the centrifugal pump are recorded, whereby the maximum speed will of course regularly be present. The operating parameter(s) are evaluated and provide information about the condition or functionality or (residual) performance of the centrifugal pump. Since it is normally known what performance the centrifugal pump is likely to achieve at maximum speed or full load, an operating parameter recorded at the maximum speed provides this information.In particular, the predefined period here is not long compared to the service life of the centrifugal pump or compared to the start-up time of the centrifugal pump, for example less than one minute, so that this information can be obtained quickly and the normal state only needs to be interrupted for a very short time or does not exist.

[0008] A key aspect of the proposed solution is that the functionality and condition of the centrifugal pump can be monitored with minimal time expenditure. The centrifugal pump does not need to be shut down, thus preventing a backlog of flow. Furthermore, the centrifugal pump usually achieves a flow rate that is slightly higher than the target, which can be easily compensated for, so that, despite monitoring the centrifugal pump—provided the performance test is actually performed—there is usually no loss of time.

[0009] Another advantage of the solution is that, with today's control technology, it is easy to retrofit existing centrifugal pumps with the solution according to the invention. The solution according to the invention can generally be implemented in practice purely from a control perspective, so that in most cases only programming of the centrifugal pump's control system will be required.

[0010] A centrifugal pump is generally a fluid machine that uses rotary motion and dynamic forces to pump liquids, predominantly as a fluid. In addition to tangential acceleration of the fluid, also called the medium, centrifugal force occurring in radial flow is used for pumping, so that centrifugal pumps are also referred to as centrifugal pumps. During normal operation of the centrifugal pump, a motor housing is preferably arranged above a pump housing, in which an impeller driven by the motor via the rotor shaft is provided for pumping the fluid. The motor housing can be fixedly connected to the pump housing and / or can be designed as a single piece. The fluid preferably comprises water or another liquid medium, such as wastewater. The motor housing is preferably made of metal, in particular stainless steel, and / or the pump housing is made of plastic.Typically, the centrifugal pump comprises a motor, an impeller driven by the motor for conveying a fluid, and a controller configured to control the motor. The centrifugal pump may include a frequency converter. A centrifugal pump without a frequency converter may also be provided, i.e., a frequency converter-free centrifugal pump.

[0011] The controller, also called a control device, preferably comprises a microcontroller, a microprocessor, an integrated circuit, or the like as an electronic component, by means of which the motor of the centrifugal pump can be controlled, for example, based on a predefined and / or adjustable program and / or based on input information such as sensors. The controller is particularly programmable. The controller can switch the centrifugal pump between the normal operating mode and the reference operating mode. The controller can control operation in the respective operating mode.

[0012] An operating mode, in particular normal operating mode or reference operating mode, is understood to mean in particular a status of the centrifugal pump.

[0013] During operation of the centrifugal pump, particularly in one of the centrifugal pump's operating modes, for example, in normal operating mode and / or in reference operating mode, a fluid is pumped. The method typically refers to the operation of the centrifugal pump. However, it may also be the case that the centrifugal pump does not pump any fluid or runs dry in normal operating mode and / or in reference operating mode. This can also be advantageous for monitoring or obtaining information.

[0014] An operating parameter is generally understood to be a measured quantity or key figure that relates specifically to the operation of the centrifugal pump. In a simple case, the operating parameter relates, for example, to the current flow rate of the centrifugal pump. The operating parameter can, for example, comprise measurement data, a signal, and / or a value. The operating parameter can represent a physical or dimensioned key figure, refer to physical quantities, and / or be a dimensionless key figure. The operating parameter can be recorded, for example, using a controller and / or a sensor. Recording can also be done by reading a dial gauge or a measuring device.

[0015] The operating parameter can be selected from a speed or a speed of a centrifugal pump motor, a discharge head, an intermediate circuit voltage, a motor current, an electrical power, an operating voltage, a volume flow, and / or a vibration function of the centrifugal pump. For the generally known control of the centrifugal pump, the intermediate circuit voltage and / or a motor current or the motor currents and / or the electrical power / power consumption of the centrifugal pump and / or the operating voltage may already be available or measured, so that they can be usefully used for monitoring. The pumped volume flow can also be known because it can be displayed for the operation of the centrifugal pump. The vibration function can be recorded at various points on the centrifugal pump, for example, with regard to electrical signals / quantities or with regard to mechanical signals / quantities, e.g.by means of a sensor assigned to the centrifugal pump, e.g., an accelerometer or similar. The vibration function is usually a time-related function of acceleration. Current and / or voltage curves can also be recorded as time-related functions to serve as at least one operating parameter.

[0016] Evaluation typically involves manual and / or computer-assisted processing of the operating parameter. For example, a signal is smoothed and / or converted. For example, the operating parameter is compared with a reference or reference value. This allows statements to be made regarding functionality or condition.

[0017] During evaluation, for example, it is assessed whether at least one operating parameter lies within a permissible value range. The permissible value range can be predefined or determined based on initial measurements, e.g. based on scatter. A vibration spectrum or frequency spectrum can be compared with a previously determined reference state or a reference value. For example, the amplitudes can be compared for each frequency and the deviation can be determined and summed up. In particular, it can be specifically checked whether the amplitudes differ at selected frequencies in the measured spectrum. Example: The amplitude ratio of the vibration at the rotational frequency to the first harmonic is analyzed. If the amplitude ratio of the current measurement is 10% greater than the reference measurement, this indicates an imbalance. Alternatively or additionally, principles of artificial intelligence (AI) orevaluated using AI methods. A large number of reference measurements or reference values, for example, obtained in normal operating mode, advantageously form a "good" cluster. It is then checked in the reference operating state whether the current measurement, i.e., at least one operating parameter, lies within this cluster.

[0018] The functionality and / or condition usually relate to the (residual) performance of the centrifugal pump. For example, the information about the functionality and / or condition quantifies whether and to what extent the centrifugal pump still achieves the desired performance.

[0019] In particular, the predefined period falls within the period of operation in the reference operating mode. In other words, the predefined period is the shortest possible duration for which the reference operating mode can exist. It is conceivable that the reference operating mode exists and that the centrifugal pump delivers a flow rate that corresponds to the flow rate in normal operating mode. The centrifugal pump does not have to be operated continuously at the maximum speed in the reference operating mode. However, it is intended that the maximum speed is reached at least for the duration of the predefined period, and that the reference operating mode is present during this time, preferably also immediately after and / or before the predefined period has been / is completed.It can be provided that in the reference operating mode, the predefined period of time predetermines the duration for which the maximum speed level may be present, so that a lower or higher speed level should be present before and after.

[0020] A speed level is the speed of the centrifugal pump in revolutions per unit of time, for example, revolutions per minute. The maximum speed level refers to the technically intended maximum speed or highest rated speed of the centrifugal pump, for example, as usually stated in the manual and / or on a nameplate. If speed levels differ from one another, this means that the speeds of the speed levels (compared in the same unit, e.g., rpm) are different. When two speed levels are mentioned, it can typically be assumed that the speed levels have different speeds.

[0021] According to a preferred development, the centrifugal pump is operated in the reference operating mode for a period of at least and / or at most 10, 30, 60, or 180 seconds. The reference operating mode should last for more or less than 10, 30, 60, or 180 seconds. For example, the reference operating mode is maintained for exactly one minute. During this time, the maximum speed level can then be reached. This ensures that the reference operating mode is present long enough, but not too long, to monitor the functionality or condition. In particular, this ensures that the operating parameter provides reliable information and that the centrifugal pump is not subjected to excessive stress.

[0022] According to another preferred development, the centrifugal pump is operated in the reference operating mode for at least one further predefined period of time with at least one further speed level. In other words, at least two speed levels are approached in the reference operating mode, one of which, in particular exactly one of which, relates to the maximum speed of the centrifugal pump. For example, the centrifugal pump can thus be gradually brought up to maximum speed or carefully moved away from the maximum speed. In particular, the centrifugal pump is operated at a lower speed level after or before operation at the maximum speed level, or after and before operation at the maximum speed level. This ensures that the operating parameter can be recorded with the greatest possible repeatability and also that the centrifugal pump is stressed as gently as possible.

[0023] According to another preferred embodiment, the predefined period is 1 to 20 seconds, preferably 5 to 15 seconds, in particular 10±5 seconds or 10±2 seconds. It has been found that such a period yields very reliable results without significantly disrupting normal operation.

[0024] It is conceivable that the centrifugal pump is operated in the reference operating mode and before and / or after the predefined period (at maximum speed level) with at least one further speed level for a further predefined period. In this respect, one or more further speed levels are added to the maximum speed level when the reference operating mode is present. The further speed level (or several of them) are of course to be provided before or after the predefined period as a further predefined period. In particular, all predefined periods added together result in the total duration or the previously described duration of the reference operating mode of e.g. 10, 15, 20, 25, 30 or another number of seconds.

[0025] Optionally, a first additional predefined period of 10±5 s with a speed corresponding to 10% to 40%, in particular 25%, of the maximum speed level is provided as a first additional speed level. In other words, the first additional speed level can, for example, specify a speed of the centrifugal pump that amounts to one-tenth to four-tenths, in particular one-quarter or 25%, of the maximum possible speed of the centrifugal pump.

[0026] Optionally, a second further predefined period of 10±5 s with a speed corresponding to 30% up to 70%, in particular 50%, of the maximum speed level is provided as a second further speed level.

[0027] Optionally, a third additional predefined period of 10±5 s with a speed corresponding to 50% up to 100%, in particular 75%, of the maximum speed level is provided as a third additional speed level.

[0028] Optionally, a fourth additional predefined period of 5±3 s with a speed corresponding to 10% up to 40%, in particular 25%, of the maximum speed level is provided as a fourth additional speed level.

[0029] The terms "first," "second," "third," "fourth," etc., are to be understood as proper nouns. An order may, but need not, be implied. The proper nouns can be interchanged at will.

[0030] During a further predefined period, the centrifugal pump should run at a defined slower speed than during the predefined period, gradually reaching the predefined period with maximum speed. This is advantageous for quickly reaching a state at maximum speed, which can be reached with high repeatability and minimal time loss. Furthermore, the departure from the predefined period, or ultimately the reference operating state, is advantageously adjusted in such a way that as few disturbances as possible occur in practice.

[0031] According to another preferred development, the evaluation comprises a comparison, in particular based on a threshold value, of the at least one operating parameter with at least one reference value for the reference operating mode. It can therefore be provided that the operating parameter is examined to determine whether threshold values ​​are exceeded or undershot. For example, a maximum and a minimum value of the operating parameter can be provided as threshold values, wherein an exceedance of the maximum value or an undershoot of the minimum value can be detected during the evaluation and can be recognized and stored as useful information about the functionality or the condition. For example, if the actual delivery rate as an operating parameter falls below an expected minimum delivery rate as a reference value, this can imply that the centrifugal pump is clogged.Threshold-based here specifically means that exceeding or falling below limits is considered. The reference value usually has the same unit as the operating parameter, so it can also have no unit, for example.

[0032] The analysis can be performed cloud-based and / or using a controller assigned to the centrifugal pump. Cloud-based means that the analysis can be performed remotely from the centrifugal pump on a server. The controller can be located locally on the centrifugal pump or physically attached to the pump.

[0033] In a preferred embodiment, in order to save data volume, the at least one operating parameter is recorded in the form of a data excerpt at a respective speed level, in particular at the maximum speed level. The data excerpt relates in particular to a time period that is shorter than a / the predefined time period. The data excerpt is in particular in the middle and / or at the end of a / the predefined time period. The data excerpt particularly preferably comprises at least the last and / or penultimate second in a predefined time period, in particular the predefined time period with the maximum speed level. This requires as little computing power as possible and saves energy and storage space. Optionally, the personnel expenditure can also be reduced.

[0034] In a preferred embodiment, the at least one reference value for the reference operating mode is selected from a motor speed, a delivery head, an intermediate circuit voltage, a motor current, an electrical power, an operating voltage, a volume flow, and / or a vibration function of the centrifugal pump. The reference value can be provided with a tolerance. The reference value can include a minimum value and / or a maximum value, in particular as a limit or threshold value. Experience has shown that very precise information about the functionality or condition can be obtained in this way.

[0035] In a preferred embodiment, the following step is provided: monitoring compliance with the reference operating mode while the centrifugal pump is operating in the reference operating mode, in particular based on a threshold value and / or by analyzing a frequency spectrum or vibration spectrum of the at least one operating parameter. In other words, not only can the reference operating mode be activated or started, it can also be checked whether, for example, the requested speed level (e.g. maximum speed level) is reached. In particular, the centrifugal pump can monitor compliance with an operating mode, in particular the reference operating mode, during operation. For example, it can be monitored for the reference operating mode whether, for example, the volume flow or the delivery rate changes significantly due to changes in the fluid system with the centrifugal pump. If this is the case, the measured data orAt least one operating parameter is not used for further analysis or evaluation. This increases reliability.

[0036] In a preferred embodiment, the evaluation comprises measuring the at least one operating parameter, in particular with regard to a vibration amplitude, storing the at least one operating parameter in a database, and / or software-based data processing. The operating parameter can thus be mathematically analyzed. This allows for highly repeatable findings to be obtained.

[0037] In a preferred embodiment, the following step is provided: determining the at least one reference value by analyzing the normal operating mode, wherein the at least one reference value is determined if the analysis shows that temporal changes of the at least one operating parameter in the normal operating mode over a temporal duration are within a predetermined range, preferably wherein the range is up to 10% and / or the duration is up to 10 seconds, and / or a vibration spectrum or frequency spectrum of the at least one operating parameter in the normal operating mode is at least substantially reproducible, and / or temporal changes of the at least one operating parameter in the normal operating mode are at least substantially reproducible. In other words, it is hereby proposed, for example, to determine the reference value such that a substantially stationary state of the centrifugal pump exists.It is preferable to set the reference value in normal operating mode and at maximum speed to achieve the best results.

[0038] In a preferred embodiment, the following step is provided: determining the at least one reference value by data processing and / or input, wherein the determination takes place before, during, and / or after operation in the normal operating mode. Preferably, the reference value of the reference operating mode is determined such that the centrifugal pump is operated below a minimum discharge head, is not operated in a pumping state, is operated in dry running, and / or is operated at the maximum speed level, in particular with a speed tolerance of ±10%.

[0039] The at least one reference value can also be determined or measured in the laboratory for several centrifugal pumps of a series. For example, the centrifugal pumps can start up the reference operating mode at defined times or in a triggered manner, in which case the at least one operating parameter can then be measured and then defined as the at least one reference value. If several centrifugal pumps are used, the extent of the scatter compared to the at least one reference value in the series can also be determined, for example in order to provide a corresponding tolerance for the at least one reference value or the at least one operating parameter. The tolerance can correspond to the scatter, be lower or higher, or correspond to a multiple of the scatter.

[0040] In a preferred embodiment, the following step is provided: triggering the centrifugal pump to be placed in the reference operating mode, wherein the triggering occurs in a time-controlled, event-controlled, and / or triggered by a trigger signal, in particular while the centrifugal pump is operating in the normal operating mode. Triggering can occur, for example, every 24 hours. Triggering can occur, for example, when it is detected that the maximum speed level is already present in the normal operating mode; in this case, the speed level is then held for at least the predefined period. Triggering can also be triggered internally, for example, by an internal algorithm of the centrifugal pump.The triggering can also be triggered externally, preferably with the trigger signal being received by a device separate from the centrifugal pump, and preferably with the centrifugal pump sending a return signal to the device about the presence of the reference operating mode. The separate device may be a central computer that monitors and / or controls at least one, but usually several, centrifugal pumps. The connection between the centrifugal pump or the centrifugal pump control system and the separate device can be wireless or wired. A BUS signal and / or a digital input can be provided for triggering. A BUS signal and / or a digital output can be provided for sending the return signal. External CM systems, such as those often provided by users of the centrifugal pump, for example content management systems, can also advantageously access the reference operating mode in this way.

[0041] Preferably, several different reference operating modes are provided in order to be able to provide information on the state of the centrifugal pump at different pumping capacities. In this way, a suitable reference operating mode can be selected, for example containing speed levels that are closer to the normal operating mode. The triggering can therefore occur in such a way that the reference operating mode into which the centrifugal pump is placed has the smallest difference from the previous normal operating mode with regard to the at least one operating parameter. Although the at least one operating parameter is regularly recorded at the maximum speed level, the at least one operating parameter can also be recorded at lower speed levels that are then closer to the selected speed levels in the normal operating mode. This can save energy and also provide even more practical insights into the residual performance of the centrifugal pump.

[0042] In a preferred embodiment, the following step is provided: aborting the operation of the centrifugal pump in the reference operating mode when an abort criterion is received. In other words, for example, an abort criterion can be provided which can be received, for example from the controller; the abort criterion should cause the reference operating mode to no longer exist. In particular, the normal operating mode should be restarted after or as a result of receiving the abort criterion. If the abort criterion has been received, the centrifugal pump can be switched off. If the abort criterion has been received, the step of operating the centrifugal pump in a compensation operating mode can be carried out alternatively or additionally. If the abort criterion has been received, the step of operating the centrifugal pump in the normal operating mode can be carried out alternatively or additionally.The termination criterion may be reaching, in particular exceeding or falling below, a deviation threshold value by the at least one operating parameter.

[0043] In a preferred embodiment, the following step is provided: processing the at least one operating parameter to provide information on a deviation in a delivery volume delivered by the centrifugal pump and / or a pressure generated by the centrifugal pump, wherein the deviation occurred due to operation in the reference operating mode. For example, it may be that due to the temporary operation in the reference operating mode, too much fluid was delivered than would actually have been delivered had the reference operating mode not been called up. In this respect, information is preferably provided on how much fluid was delivered in excess in order to have a basis for deciding whether the deviation should be corrected.

[0044] In particular, operation of the centrifugal pump in a / the compensation operating mode is provided to compensate for the deviation, preferably by temporarily adjusting—for example, reducing or increasing—the speed of a / the motor, a delivery head, an intermediate circuit voltage, a motor current, an electrical power, an operating voltage, and / or a volume flow. Alternatively or additionally, operation of the centrifugal pump in the compensation operating mode can be provided in such a way that the deviations are at least substantially compensated on average over time.

[0045] During the reference operating mode, the centrifugal pump typically does not control according to the control task otherwise desired by the customer, which is regularly specified in the normal operating mode. The resulting deviation should be identified and compensated for using the compensation operating mode. The following approaches are particularly suitable for this purpose.

[0046] In the case of flow control, the centrifugal pump's task is to keep the flow constant. In this case, the centrifugal pump can accumulate a flow deviation and temporarily increase and / or decrease the target flow upon or after leaving the reference operating mode, so that the desired flow is delivered on average over the entire period.

[0047] In the case of differential pressure control, the centrifugal pump's task is to keep the differential pressure constant. In this case, the centrifugal pump can accumulate the differential deviation and, after leaving the reference operating mode, temporarily increase and / or decrease the target flow rate so that the desired differential pressure is provided on average over the entire period.

[0048] If the reference state is aborted, it is the task of the centrifugal pump, particularly by means of an internal control function of the centrifugal pump, to determine the actual speed level to be set based on the measured data or the at least one operating parameter and a setpoint specification. If a resulting deviation from the reference operating mode exceeds a specified value (or the integral of this deviation reaches a specified value), the reference operating mode is exited and the centrifugal pump returns to normal operating mode. Optionally, the reference operating mode can then be reached at a later state.

[0049] Furthermore, a centrifugal pump is proposed that has a controller configured to carry out the method described herein. The controller may be configured to be specifically programmed to implement the method. Therefore, not just any centrifugal pump with a programmable controller can be considered the centrifugal pump proposed here; rather, appropriate programming must also be provided or implemented. Short description of the drawings

[0050] The invention is explained in more detail below with reference to the attached drawings using preferred embodiments.

[0051] The drawings show Fig. 1 is a schematic view of a method with a centrifugal pump according to a preferred embodiment of the invention, and Fig. 2 is a schematic view of a method with a centrifugal pump according to a further preferred embodiment of the invention, which is provided on a cloud-based basis. Detailed description of the implementation examples

[0052] Fig. 1 and Fig. 2 each show a centrifugal pump 1 with a motor, an impeller driven by the motor for conveying a fluid, and a controller. The controller is designed to carry out a method according to the invention that enables advantageous monitoring of the centrifugal pump 1. In Fig. 2 Furthermore, a cloud 2 is shown, which is intended in particular for evaluation 40 and triggering 15.

[0053] With reference to Fig. 1a method for monitoring the functionality and / or condition of a centrifugal pump is shown. Here, individual reference numerals 10, 15, 20, 50, 60, 70 represent essentially chronologically executed steps or milestones and / or trigger points of the method. The method begins, for example, in step 10 with operation of the centrifugal pump 1 in a normal operating state, for example, where a fluid is pumped in a controlled manner according to customer requirements. Step 15 will regularly result in a triggering event. In this respect, triggering 15 puts the centrifugal pump 1 into a reference operating mode, which is then present in step 20, with triggering 15 occurring in a time-controlled manner, specifically during operation 10 of the centrifugal pump 1 in the normal operating mode.The transition from step 10 to step 20 usually occurs by increasing the engine speed to maximum speed, so that the engine operates at its technically designed maximum speed. This usually takes a short moment, e.g., less than 10 seconds. If the maximum speed is already present in step 10, the transition essentially occurs instantaneously.

[0054] The trigger signal in step 15 can optionally be received by a device separate from the centrifugal pump 1, whereby the centrifugal pump 1 can send a feedback signal to the device indicating that the reference operating mode is present. However, triggering 15 can also occur time-based, for example, every 24 hours.

[0055] The trigger 15 is with regard to Fig. 2This is optionally realized by Cloud 2 initiating the triggering 15 via a trigger signal. The return signal can then be sent from centrifugal pump 1 back to Cloud 2.

[0056] In this case, several different reference operating modes are provided to provide information on the status of the centrifugal pump 1 at different pumping capacities. Triggering 15 is regularly performed such that the selected reference operating mode, to which the centrifugal pump 1 is placed, exhibits the smallest possible difference from the previous normal operating mode 10 with respect to an operating parameter.

[0057] The reference operating mode is maintained for a period of 10 to 180 seconds. During the reference operating mode, centrifugal pump 1 is operated at a maximum speed level or maximum speed for a predefined period of time. In this case, the predefined period is exactly ten seconds or 10 s.

[0058] Before and after the predefined period, while still in reference operating mode, centrifugal pump 1 is operated for further predefined periods at lower speed levels that are close to the normal operating mode. A first predefined period, lasting 10 s, provides a speed of 50% of the maximum speed level as the first additional speed level at which centrifugal pump 1 is to be operated. A second predefined period, lasting 5 s, provides a speed of 25% of the maximum speed level as the second additional speed level. Optionally, further speed levels or predefined periods can be provided. The sum of all predefined periods here is therefore 10 s + 10 s + 5 s = 25 s, which should be the reference operating mode for the period of 25 s.

[0059] In step 22, additional monitoring of compliance with the reference operating mode during operation 20 of the centrifugal pump 1 in the reference operating mode is carried out, specifically threshold-based and / or by analyzing a frequency spectrum or vibration spectrum of the at least one operating parameter.

[0060] During operation 20 of the centrifugal pump 1 in the reference operating mode, step 30 is provided. In step 30, at least one operating parameter of the centrifugal pump 1 is recorded. At least during this time, the centrifugal pump 1 is operated at the maximum speed level or maximum speed for at least the predefined period of time.

[0061] The at least one operating parameter in the present case is an oscillation function, in particular containing an acceleration of the centrifugal pump 1, and additionally a volume flow.

[0062] Following the detection 30 and / or during the detection 30, the at least one operating parameter can be evaluated in step 40, in particular still during operation 20. The evaluation 40 is provided for obtaining information about the functionality and / or the state of the centrifugal pump 1.

[0063] The evaluation 40 takes place within the centrifugal pump 1 or by means of the control system assigned to the centrifugal pump 1. To save data volume, the at least one operating parameter is recorded in the form of a data excerpt from the maximum speed level, whereby the data excerpt covers only the last two seconds within the predefined period. In other words, the oscillation function is recorded or viewed only in the ninth and tenth seconds of the predefined period, which in this case is 10 seconds.

[0064] Referring to Fig. 2It should be noted that this is essentially an identical procedure as in Fig. 1 is carried out. Deviating from Fig. 1 is in Fig. 2 However, it is intended that the evaluation 40 is carried out in the previously mentioned Cloud 2, i.e., away from the centrifugal pump 1. For this purpose, at least one operating parameter is transmitted to Cloud 2, for example, wirelessly or wired. For this purpose, the arrow from 30 to 40 is shown dashed.

[0065] The evaluation 40 comprises a threshold-based comparison 42 of the at least one operating parameter with at least one reference value for the reference operating mode. The at least one reference value comprises, by way of example—like the at least one operating parameter—a vibration function of the centrifugal pump 1 and a volume flow of the centrifugal pump 1. A comparison can be made as to whether the volume flow in the reference operating mode corresponds to the volume flow of the reference value or to what extent the volume flow in the reference operating mode deviates from it.

[0066] The evaluation 40 also includes measuring 44 the at least one operating parameter, in particular with regard to a vibration amplitude. Furthermore, storing 46 of the at least one operating parameter in a database and software-based data processing are provided.

[0067] Furthermore, an interruption 50 of the operation 20 of the centrifugal pump 1 in the reference operating mode is provided, in particular when an interruption criterion is received. Once the interruption criterion has been received, the centrifugal pump 1 can be switched off as needed. In this case, upon receipt of the interruption criterion, an operation 60 of the centrifugal pump 1 in a compensation operating mode is provided, or a switching of the centrifugal pump 1 into the compensation operating mode is provided. When the compensation operating mode is terminated, an operation 70 in the normal operating mode is provided again, which is essentially equivalent to operation 10 and thus closes the chronological cycle. Alternatively, the step of operating 70 of the centrifugal pump 1 in the normal operating mode can also be performed directly, without step 60.The termination criterion in this case is the reaching of a deviation threshold value by the at least one operating parameter by considering whether an integral of the volume flow exceeds a threshold value.

[0068] In a step 48, typically before the termination 50, processing of the at least one operating parameter is provided in this case to provide information on a deviation in a delivery volume pumped by the centrifugal pump 1 and / or a pressure generated by the centrifugal pump 1. The deviation occurred due to operation 20 in the reference operating mode. The deviation can be used, if necessary, in step 60 or operation 60, which is why a dashed arrow leads from 48 to 60 here. In this respect, operation 60 of the centrifugal pump 1 in the compensation operating mode is provided to compensate for the deviation, for example by operating the centrifugal pump 1 in such a way that the deviations are balanced out on average over time.

[0069] The method also includes steps 12 and 14. In step 12, determining, the previously mentioned at least one reference value is determined. This can be done by analyzing the normal operating mode, wherein the at least one reference value is determined if the analysis shows that temporal changes of the at least one operating parameter in the normal operating mode lie within a predetermined range over a period of time, and / or that a vibration spectrum or frequency spectrum of the at least one operating parameter in the normal operating mode is at least substantially reproducible, and / or that temporal changes of the at least one operating parameter in the normal operating mode are at least substantially reproducible.

[0070] In step 14, "Determining," the at least one reference value is determined by data processing and / or input. Determining 14 can occur before, during, and / or after operation 10, 70 in the normal operating mode. The reference value is determined, in particular, such that the centrifugal pump 1 is operated below a minimum discharge head, is not operated in a pumping state, is operated in dry running, and / or is operated at the maximum speed level, in particular with a speed tolerance of ±10%.

[0071] The described embodiments are merely examples that can be modified and / or supplemented in a variety of ways within the scope of the claims. Each feature described for a specific embodiment can be used independently or in combination with other features in any other embodiment. Any feature described for an embodiment of a particular category can also be used in a corresponding manner in an embodiment of a different category. List of reference symbols

[0072] Centrifugal pump 1 Cloud 2 Operate (normal operating mode) 10 Establish 12 Establish 14 Trigger 15 Operate (reference operating mode) 20 Monitor 22 Capture 30 Evaluate 40 Compare 42 Surveying 44 Save from 46 Process 48 Cancel 50 Operate (compensation operating mode) 60 Operate (normal operating mode) 70

Claims

1. Method for monitoring a functionality and / or a state of a centrifugal pump (1), comprising the steps of: during operation (20) of the centrifugal pump (1) in a reference operating mode, detecting (30) at least one operating parameter of the centrifugal pump (1), evaluating (40) the at least one operating parameter to obtain information about the functionality and / or the state of the centrifugal pump (1), and operating (10, 70) the centrifugal pump (1) in a normal operating mode before and / or after operation (20) of the centrifugal pump (1) in the reference operating mode, wherein the centrifugal pump (1) is operated at a maximum speed level in the reference operating mode at least for a predefined period of time.

2. Method according to the preceding claim, wherein the operation (20) of the centrifugal pump (1) in the reference operating mode is carried out for a period of at least and / or at most 10, 30, 60 or 180 seconds.

3. Method according to one of the preceding claims, wherein the centrifugal pump (1) is operated in the reference operating mode for at least one further predefined period of time with at least one further speed level, and is preferably operated with a lower speed level after and / or before operation with the maximum speed level.

4. Method according to one of the preceding claims, wherein the predefined period of time is 10±5 s, and preferably the centrifugal pump (1) in the reference operating mode and before the predefined period of time optionally for a first further predefined period of time of 10±5 s at a speed corresponding to 10% up to 40%, in particular 25%, of the maximum speed level as a first further speed level, and optionally for a second further predefined period of time of 10±5 s at a speed corresponding to 30% up to 70%, in particular 50%, of the maximum speed level as a second further speed level, and optionally for a third further predefined period of time of 10±5 s at a speed corresponding to 50% up to 100%, in particular 75%, of the maximum speed level as a third further speed level, and after the predefined period of time optionally for a fourth further predefined period of 5±3 s at a speed corresponding to 10% up to 40%, in particular 25%,the maximum speed level is operated as a fourth additional speed level., 5. Method according to one of the preceding claims, wherein the evaluation (40) comprises a particularly threshold-based comparison (42) of the at least one operating parameter with at least one reference indication for the reference operating mode and / or is carried out cloud-based or by means of a controller assigned to the centrifugal pump (1).

6. Method according to one of the preceding claims, wherein, in order to save data volume, the at least one operating parameter is recorded in the form of a data excerpt at a respective speed level, in particular at the maximum speed level, wherein the data excerpt comprises in particular at least one last and / or penultimate second in a predefined period of time.

7. Method according to one of the preceding two claims, wherein the at least one reference indication for the reference operating mode is selected from a speed of a motor, a delivery head, an intermediate circuit voltage, a motor current, an electrical power, an operating voltage, a volume flow and / or an oscillation function of the centrifugal pump (1).

8. Method according to one of the preceding claims, comprising the step: monitoring (22) compliance with the reference operating mode during operation (20) of the centrifugal pump (1) in the reference operating mode, in particular threshold-based and / or by analyzing a frequency spectrum of the at least one operating parameter.

9. Method according to one of the preceding claims, wherein the evaluation (40) comprises measuring (44) the at least one operating parameter, in particular with regard to a vibration amplitude, storing (46) the at least one operating parameter in a database and / or software-based data processing.

10. Method according to one of the preceding claims, comprising the step: determining (12) the at least one reference value by analyzing the normal operating mode, wherein the at least one reference value is determined if the analysis shows that temporal changes of the at least one operating parameter in the normal operating mode over a temporal duration are within a predetermined range, preferably wherein the range is up to 10% and / or the duration is up to 10 seconds, and / or a vibration spectrum of the at least one operating parameter in the normal operating mode is at least substantially reproducible, and / or temporal changes of the at least one operating parameter in the normal operating mode are at least substantially reproducible.

11. Method according to one of the preceding claims, comprising the step: determining (14) the at least one reference value by data processing and / or an input, wherein the determining (14) takes place before, during and / or after operation (10) in the normal operating mode, preferably wherein the reference value of the reference operating mode is determined such that the centrifugal pump (1) is operated below a minimum delivery head, is not operated in a delivery state, is operated in dry running and / or is operated at the maximum speed level, in particular with a speed tolerance of ±10%.

12. Method according to one of the preceding claims and comprising the step: triggering (15) that the centrifugal pump (1) is placed in the reference operating mode, wherein the triggering (15) is time-controlled, event-controlled and / or carried out by a trigger signal, in particular during operation (10, 70) of the centrifugal pump (1) in the normal operating mode, preferably wherein the trigger signal is received by a device separate from the centrifugal pump (1), and wherein the centrifugal pump (1) sends a return signal to the device about the presence of the reference operating mode.

13. Method according to one of the preceding claims, wherein a plurality of different reference operating modes are provided in order to be able to provide information on the state of the centrifugal pump (1) at different pumping powers, in particular wherein the triggering (15) takes place in such a way that the reference operating mode into which the centrifugal pump (1) is placed has the smallest difference to the previous normal operating mode (10, 70) with regard to the at least one operating parameter.

14. Method according to one of the preceding claims and comprising the step: aborting (50) the operation (20) of the centrifugal pump (1) in the reference operating mode when an abort criterion is received, wherein, when the abort criterion has been received, the centrifugal pump (1) is switched off, or the step: operating (60) the centrifugal pump (1) in a compensation operating mode or the step: operating (70) the centrifugal pump (1) in the normal operating mode is carried out, in particular wherein the abort criterion is the reaching of a deviation threshold value by the at least one operating parameter.

15. Method according to one of the preceding claims and comprising the steps of: processing (48) the at least one operating parameter to provide information on a deviation of a delivery volume delivered by the centrifugal pump (1) and / or a pressure generated by the centrifugal pump (1), wherein the deviation has occurred due to operation (20) in the reference operating mode, operating (60) the centrifugal pump (1) in a / the compensation operating mode to compensate for the deviation, preferably by temporarily adjusting the speed of a motor, a delivery head, an intermediate circuit voltage, a motor current, an electrical power, an operating voltage, a volume flow and / or by operating the centrifugal pump (1) in the compensation operating mode such that the deviations are compensated on average over time.

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