MEASURING AND / OR CONTROL DEVICE FOR A FLUID DYNAMIC SYSTEM AND CORRESPONDENT METHOD

Description

[0001] The present invention relates to a measuring and / or control device for a fluid dynamic system according to the preamble of claim 1, a fluid dynamic system according to the preamble of claim 10 and a corresponding method according to the preamble of claim 13.

[0002] Fluid dynamic systems can be open or closed systems in which one or more fluids are conveyed and / or pressurized. The fluids can be compressible (e.g., gases, especially air) or incompressible (liquids, especially water or oil). In fluid dynamic systems, active components, such as turbomachines or positive displacement machines, pumps, control valves, especially electrically actuated valves, and / or passive components, such as boilers, radiators, and / or heat exchangers, can be connected by pipes or tubes, resulting in a piping system within the fluid dynamic system. Fundamentally, the combination of a turbomachine or positive displacement machine and an associated system constitutes a fluid dynamic system. Fluid dynamic systems are used, for example, in water supply, heating, and / or air conditioning systems, as well as in chemical and process engineering.

[0003] Fluid dynamic systems can reach a high degree of complexity and are characterized by a multitude of possible system states. These states can be described by the number and settings of the installed fluid dynamic components, such as fittings, valves, actuators, pressure accumulators, tanks, and reservoirs, as well as the operating state of the flow or positive displacement machine, such as rotational speed, flow rate, and delivery head. The complexity and temporal variability of the fluid dynamic system can mean that it is not typically measurable or identifiable in this sense.

[0004] In fluid dynamic systems, pressure changes can be introduced into the fluid dynamic system, particularly by active components such as hydrostatic and hydrodynamic turbomachinery, especially pumps, compressors or compressors, whose purpose is fluid transport, as well as valves. These pressure changes propagate as wave-like pressure fluctuations or pressure pulsations at the speed of sound and are reflected or absorbed and transmitted at locations with a sudden change in acoustic impedance, for example walls, valves or silencers.

[0005] When operating such a fluid dynamic system, a defined pressure or volume flow rate is required at specific points or consumers, depending on the task. The system therefore always has a defined demand that must be met by the fluid or positive displacement machine, for example, a pump. Ideally, the fluid or positive displacement machine supplies precisely the required flow rate for the system and thus operates energy-efficiently at the optimal operating point for the respective system state of the entire fluid dynamic system.

[0006] These system states are typically unknown, especially in more complex systems, and are subject to change over time due to factors such as altered valve positions, changes in hydraulic actuators, or system wear. Consequently, the actual requirements for the fluid or positive displacement machine, particularly a pump—i.e., the system's energy needs—are generally unknown. Therefore, the fluid or positive displacement machine is always operated in such a way that the requirements are met in every case. As a result, the operation of the fluid or positive displacement machine always consumes more energy than would actually be necessary, which is energy-inefficient.

[0007] From BÜKER JOHANNES ET AL: "Active noise cancellation applied to a centrifugal pump in a closed loop piping system", APPLIED ACOUSTICS, ELSEVIER PUBLISHING, GB, Vol. 178, 2021-03-02, ISSN; 0003-682X, a hydrodynamic actuator for the active and adaptive reduction of dynamic pressure pulses is known.

[0008] JP H05 332491 A discloses an active accumulator that reduces pressure pulsations in a line carrying flowing liquid.

[0009] An active damper for suppressing dominant harmonic pressure fluctuations in a fluid pipeline is known from PAN M ET AL: "Hybrid Fluid-borne Noise Control in Fluid-filled Pipelines", JOURNAL OF PHYSICS. CONFERENCE SERIES; Vol. 744, 2016-09-01, Page 012016, GB, ISSN: 1742-6588.

[0010] It is therefore an object of the present invention to provide a measuring and / or control device for a fluid dynamic system, a fluid dynamic system and a method for operating a measuring and / or control device for a fluid dynamic system, which overcome the aforementioned disadvantages.

[0011] The invention solves this problem with the features of the independent claims. Further preferred embodiments of the invention can be found in the dependent claims and the associated descriptions and drawings.

[0012] According to the basic concept of the application, a measuring and / or control device for a fluid dynamic system is proposed, wherein the fluid dynamic system comprises a turbomachine or positive displacement machine, ducts, and at least one further fluid dynamic component. The measuring and / or control device comprises at least a first pressure sensor, a pressure fluctuation generator for actively reducing pressure fluctuations in the fluid dynamic system, and a first control unit with an adaptive filter having a plurality of filter coefficients.The first control unit is configured to receive a pressure fluctuation signal from the first pressure sensor, receive or generate a reference signal, and generate a control signal from the reference signal using the adaptive filter. It then controls the pressure fluctuation generator with the control signal and continuously optimizes or adjusts the adaptive filter to minimize the pressure fluctuation signal. It is proposed that the measurement and / or control system include a second control unit configured to evaluate the filter coefficients of the adaptive filter of the first control unit, preferably continuously. to identify changes in the fluid dynamic system from changes in the filter coefficients over time; and / or to assign the filter coefficients to known system states of the turbo or displacement machine and / or the fluid dynamic system and / or parts of the fluid dynamic system; and / or to control the power and / or speed of the turbo or displacement machine of the fluid dynamic system to an efficient, in particular optimal, operating point of the turbo or displacement machine in the fluid dynamic system by evaluating the filter coefficients.

[0013] Accordingly, the measuring and / or control device is initially set up to compensate for pressure fluctuations in the fluid dynamic system.

[0014] The positive displacement machine is a primary source of pressure fluctuations in the fluid dynamic system, manifesting as dynamic changes or pulses in the pressure over time. These pressure fluctuations or oscillations represent unwanted losses and excitation of vibrations in the piping system. A positive displacement machine is, for example, a fluid dynamic pump. A positive displacement machine can be a fluid dynamic pump, such as a side-channel, radial, or axial pump, particularly a circulating pump. Furthermore, a positive displacement machine can be, for example, a compressor. A positive displacement machine can, in particular, be a piston machine, which preferably has a cycle frequency that corresponds to the rotational speed of a shaft of the piston machine. The positive displacement machine is preferably a speed-driven and / or speed-controlled positive displacement machine.

[0015] Pressure fluctuations are preferably measured downstream of the turbo or positive displacement machine by means of the first pressure sensor and converted into a pressure fluctuation signal, which is received by the first control unit. The pressure fluctuation signal is time-varying according to the existing pressure fluctuations, which occur particularly in the lines of the fluid dynamic system. The first pressure sensor is preferably arranged downstream of the turbo or positive displacement machine and the pressure fluctuation generator.

[0016] The pressure sensor is designed to measure the corresponding pressure, in particular the acoustic pressure. The pressure measurement by the pressure sensor can be performed using various methods, for example, strain gauges and / or accelerometers. The pressure sensor is preferably a type of transducer that converts an acoustic signal into an electrical signal.

[0017] The pressure fluctuations exhibit a dynamic pressure change over time, based on the static pressure in the fluid dynamic system. Static pressure can therefore also be understood as a mean or averaged pressure around which the pressure fluctuations oscillate.

[0018] The reference signal is received by the first control unit or, preferably, generated by the control unit and preferably comprises at least one sinusoidal oscillation. The amplitude of the sinusoidal oscillation in the reference signal preferably assumes a preset value. The reference signal may comprise further sinusoidal oscillations, the frequencies of which preferably correspond to an integer multiple of the first frequency. The further sinusoidal oscillations preferably have a lower, preset amplitude than the first sinusoidal oscillation. In alternative embodiments, the reference signal received or, preferably, generated by the first control unit may not comprise a sinusoidal oscillation, particularly in the case of a broadband reference signal.

[0019] The reference signal is filtered in the first controller unit using an adaptive filter, in particular a digital filter. Preferably, a finite impulse response filter (FIR filter) or an infinite impulse response filter (IIR filter), or a combination of these two filters, is used and implemented accordingly in the first controller unit. The filter has corresponding filter parameters that can modify the amplitude, phase, and / or frequency of the reference signal. After passing through the filter, the reference signal is referred to as the control signal, which is generated by the first controller unit. The filter, in particular the FIR filter, is adaptive, so that its behavior can be changed during operation, especially by adjusting the filter parameters.

[0020] The pressure fluctuation generator is controlled and operated with the control signal, which is additionally amplified in advantageous embodiments.

[0021] The effect of the interference between the pressure fluctuations of the fluid dynamic system or the turbo or displacement machine with the pressure fluctuations of the pressure fluctuation generator can be measured with the first pressure sensor downstream of the turbo or displacement machine, which detects the pressure fluctuations and generates a corresponding pressure fluctuation signal, which in turn is transmitted to the first control unit.

[0022] Accordingly, after an optimization phase, the adaptive filter, particularly through adjustment and optimization of the filter parameters, adjusts the reference signal to achieve the most destructive interference possible with pressure fluctuations. This reduces the pressure fluctuations in the fluid dynamic system, resulting in lower acoustic emissions and reduced resistance. The continuous optimization process allows for automatic adaptation to changes in the fluid dynamic system, such as the opening or closing of individual valves.

[0023] According to the proposed solution, the filter coefficients of the adaptive filter of the first control unit are continuously evaluated by the second control unit. Evaluating the filter coefficients used for the active reduction of pressure fluctuations allows the system states, particularly of the turbomachine or positive displacement machine, to be identified. This is especially advantageous for fluid dynamic systems that, due to their nature, size, and / or complexity, cannot be measured and / or are subject to constant changes.

[0024] The compensation of pressure fluctuations makes it possible in the regular operation of the fluid dynamic system to absorb the corresponding filter coefficients that describe the system and the system state, while simultaneously reducing the pressure fluctuations in the fluid dynamic system and the sound emissions of the fluid dynamic system.

[0025] The invention recognizes that pressure fluctuation compensation, which can also be understood as active noise canceling, enables the detection and description of the system state of a fluid dynamic system, with the corresponding values ​​being directly derived from the filter coefficients of the adaptive filter. Therefore, fluid dynamic systems that are inaccessible to conventional system identification methods can be identified and, in particular, continuously identified and evaluated during regular operation. Furthermore, this allows for acoustic decoupling of the turbo or displacement machine from the system or the rest of the fluid dynamic system during evaluation, so that the emitted pressure pulsations of the turbo or displacement machine are not reflected in the system or other parts of the fluid dynamic system and cannot act on the turbo or displacement machine again.In other words, the fluid or displacement machine is silenced from the perspective of the other parts of the system.

[0026] The filter coefficients represent the acoustic behavior of the fluid dynamic system, so that changes in acoustic behavior far from the first pressure sensor can also be detected.

[0027] The evaluation of the filter coefficients in the second control unit preferably allows for the identification of changes in the fluid dynamic system based on the changes in the filter coefficients over time. This enables conclusions to be drawn about changes, for example, in the flow or positive displacement machine system, particularly in the pump system. Preferably, the frequency band to be canceled out is divided across several adaptive filter channels, so that low-amplitude frequency components in the canceled pressure oscillations can be specifically distinguished and finely resolved. The filter coefficients generally correspond in their amplitude and sequence to the canceled oscillation components.

[0028] A change in the system state or system properties results in a change in the sound field and the filter coefficients, since the filter coefficients are continuously adjusted by the adaptive filter in response to changes in the sound field. The altered weighting of the filter coefficients, or the set of filter coefficients, thus allows conclusions to be drawn about changes in the system. The fluid dynamic system can therefore be continuously monitored during operation, and the system states can be identified (condition monitoring).

[0029] Alternatively or additionally, the evaluation of the filter coefficients in the second control unit can preferably be used to assign them to known system states of the turbomachine or positive displacement machine and / or the fluid dynamic system and / or parts of the fluid dynamic system. A specific system state, in particular a static system state, results in a characteristic set of filter coefficients, e.g., filter weights and parameters, during the continuous optimization of the adaptive filter.

[0030] The assignment can be made, for example, by comparing the filter coefficients with one or more sets of filter coefficients of a known system state. This allows, for example, effective monitoring and measurement (condition monitoring) of the fluid dynamic system and, in particular, of the turbomachine or positive displacement machine, such as a pump.

[0031] In advantageous embodiments, the second control unit comprises a neural network which is trained on the basis of known states, properties and / or events of the fluid dynamic system, in particular the flow or displacement machine, such that after the training process the training data can be correctly assigned to the corresponding states, properties and / or events.

[0032] For example, during training, the nodes and weights of the neural network can be iteratively adjusted using a learning algorithm based on the recognition error. The recognition error arises between the fluid dynamic system to be recognized, or its system state (particularly a flow or displacement machine), and the system or system state recognized by the neural network. The data points of the training data can be assigned to the nodes of the neural network individually or in groups, according to the quantity per data set and the system-related qualitative composition. By correctly recognizing and assigning known system states, properties, and events, these can be distinguished from unknown system states, properties, and events during operation of the fluid dynamic system.In this way, normal system states can be distinguished from abnormal system states, particularly of the turbomachine or positive displacement machine, so that, among other things, wear or damage to the turbomachine or positive displacement machine can be detected early. This allows maintenance work and repairs on the fluid dynamic system to be planned in a timely and efficient manner, thus enabling predictive maintenance.

[0033] Alternatively or additionally, the measuring and / or control device preferably regulates the power and / or speed of the turbo or displacement machine of the fluid dynamic system by evaluating the filter coefficients to find an efficient operating point, preferably the best efficiency point, of the turbo or displacement machine in the fluid dynamic system. The invention recognizes that a corresponding turbo or displacement machine in a fluid dynamic system, when operating at its best efficiency point (BEP), i.e., at an operating point with maximum efficiency, exhibits a characteristic acoustic behavior, which can be detected by the measuring and / or control device using the filter coefficients of the adaptive filter. The corresponding set of filter coefficients can therefore be compared with a corresponding operating point. In simplified terms, a specific sound or...A specific set of filter coefficients can be assigned to a specific operating point of the turbomachine or positive displacement machine. The evaluation of the filter coefficients to an efficient operating point, preferably BEP, of a turbomachine or positive displacement machine within a fluid dynamic system is possible by the measuring and / or control device even with dynamic characteristic curves in fluid dynamic systems when the turbomachine or positive displacement machine interacts with the rest of the fluid dynamic system.

[0034] To control the turbo or displacement machine, an optimal rotational speed for the turbo or displacement machine can be determined depending on the identified system state and, for example, output as a target rotational speed.

[0035] Such an evaluation of the acoustic behavior of the flow or displacement machine is possible through the active compensation of the pressure fluctuations of the entire fluid dynamic system, especially for complex, time-varying and unknown systems, whereby the evaluation is achieved directly through the filter coefficients used for the active compensation.

[0036] The proposed measuring and / or control device enables demand-based control of turbomachines or positive displacement machines in fluid dynamic systems, ensuring that the turbomachine or positive displacement machine can always be operated energy-efficiently, even if the actual system demand is unknown. This allows for significant energy and cost savings in a fluid dynamic system. Furthermore, the service life of the turbomachine or positive displacement machine, or its maintenance intervals, can be extended, as it can be operated according to demand. Operating the turbomachine or positive displacement machine at a speed exceeding its actual requirements in order to constantly meet demand is thus avoided. For example, an optimal rotational speed for the turbomachine or positive displacement machine can be determined and output based on the detected system state.

[0037] It is further proposed that the second control unit be configured to evaluate the filter coefficients for the characteristic acoustic behavior of the turbo or positive displacement machine. This evaluation of the characteristic acoustic behavior of the turbo or positive displacement machine is only possible through the compensation of pressure fluctuations, as it is acoustically decoupled from the other parts of the system or plant. Acoustic decoupling is essential here, because otherwise the turbo or positive displacement machine noise would be reflected within the system and superimposed in the turbo or positive displacement machine or the measurement. This typically results in measurement signals from turbo or positive displacement machine acoustics being recorded with low signal quality. Only through acoustic decoupling can the measurement signals be used with good quality for evaluation, system identification, and / or control.Through appropriate analysis, it can be determined whether the turbomachine or positive displacement machine is operating at an efficient operating point, particularly at the optimal operating point (BEP), or whether it can be controlled to operate at this point. Operating the turbomachine or positive displacement machine above the requirements of the fluid dynamic system can thus be avoided, which significantly increases energy efficiency.

[0038] According to a further development, it is proposed that the second control unit comprises a neural network trained to recognize characteristic acoustic behavior of a fluid or displacement machine from the filter coefficients. Using a neural network, characteristic acoustic behavior can be recognized in the abstract sets of filter coefficients.

[0039] According to a further development, it is proposed that the second control unit be configured to identify a characteristic system state of the turbomachine or positive displacement machine from the evaluation of the filter coefficients. This characteristic behavior could, for example, correspond to the behavior during operation at the turbomachine or positive displacement machine's optimal operating point.

[0040] Furthermore, it is proposed that the second control unit be configured to identify a characteristic system state of at least one other fluid dynamic component, for example, a boiler, basin, or fittings, preferably the system itself, from the evaluation of the filter coefficients. This is made possible by acoustic decoupling from the flow or displacement machine, so that the system states of other components can be identified, which can be used, for example, for their condition monitoring and maintenance planning.

[0041] It is further proposed that the second control unit be configured to regulate the turbo or positive displacement machine to a specific characteristic acoustic behavior. In advantageous embodiments, the rotational speed or the target rotational speed of the turbo or positive displacement machine can be controlled and / or regulated accordingly, so that a specific system state, for example, operation of the turbo or positive displacement machine at its optimal point, is achieved.

[0042] According to a further development, it is proposed that the second control unit be configured to store the filter coefficients. This storage can be continuous or at intervals. In this way, for example, the filter coefficients can be compared at different times, allowing even gradual changes in the fluid dynamic system to be detected and evaluated.

[0043] In a preferred embodiment, the actual rotational speed of the fluid or displacement machine can be detected and received by the first control unit, wherein the first control unit is configured to generate the reference signal from the actual rotational speed of the fluid or displacement machine.

[0044] The reference signal is thus generated depending on the detected rotational speed of the turbo or displacement machine and is therefore subject to the same temporal changes as the rotational speed of the turbo or displacement machine.

[0045] The rotational speed of a turbomachine or positive displacement machine can be detected, for example, using a speed sensor. Furthermore, in the case of electrically driven turbomachines or positive displacement machines, the rotational speed can sometimes be directly detected from the machine's electrical control circuitry, allowing the rotational speed to be received as a variable measurement by the control unit.

[0046] In addition to this variable measurement, preferred embodiments also provide a constant parameter of the fluid or displacement machine, in particular the number of impeller blades or rotor blades and / or guide vanes, on the control unit.

[0047] Furthermore, a change in the rotational speed of the turbomachine or positive displacement machine can be directly incorporated into the reference signal, without having to wait for the optimization phase to adapt to the modified system due to the altered rotational speed. Therefore, a change in the rotational speed of the turbomachine or positive displacement machine does not necessarily result in a significant adjustment of the filter parameters, thus considerably shortening the optimization phase until an optimum is reached. Through continuous optimization, a change in the rotational speed of the turbomachine or positive displacement machine, and consequently a change in the reference signal, is addressed both by the altered reference signal and by the continuous optimization or adaptation of the filter.

[0048] The pressure fluctuations generated by a turbomachine or positive displacement machine, in particular a pump, generally correspond approximately to an integer multiple of the rotational speed of the turbomachine or positive displacement machine in the case of a single-stage turbomachine or positive displacement machine, whereby the frequency or frequencies of these pressure fluctuations depend on the rotational speed and the type of turbomachine or positive displacement machine.

[0049] In an alternative embodiment, the measuring and / or control device comprises at least one second pressure sensor, and the first control unit is configured to receive a second pressure fluctuation signal as a reference signal from the second pressure sensor. The pressure fluctuations to be detected by the second pressure sensor are preferably measured between the fluid or displacement machine and the pressure fluctuation generator, so that they can be used as a reference signal in the measuring and / or control device.

[0050] This embodiment is particularly suitable for broadband acoustic excitations of a fluid dynamic system.

[0051] The measuring and / or control device may contain several primary pressure sensors. Furthermore, the measuring and / or control device may contain several secondary pressure sensors. The secondary pressure sensor can, in principle, be identical in design to the primary pressure sensor.

[0052] Preferably, the pressure fluctuation generator is controlled and operated by the control signal, which in advantageous embodiments is additionally amplified. The pressure fluctuation generator produces longitudinal pressure waves by using an oscillating source surface of the oscillator. The pressure fluctuation generator can, for example, be a fluid-static actuator. The pressure waves or pressure fluctuations preferably propagate initially in the longitudinal direction of a connecting pipe of the fluid-dynamic system in which the pressure fluctuation generator is positioned, before interfering with the other pressure fluctuations in the system. The source surface is preferably planar. However, the source surface can also be designed in a non-planar manner.

[0053] In advantageous embodiments, the connecting pipe, in which the pressure fluctuation generator is preferably arranged, is connected to the fluid dynamic system via a connecting piece. The geometric design of the connecting piece can vary depending on the application. For example, the connecting piece can be designed as an angled T- or Y-piece, or as an arc-shaped piece. The cross-section of the connecting pipe can also vary depending on the application. Preferably, the pressure fluctuations in the fluid dynamic system, in particular from the turbomachine or positive displacement machine, are superimposed on the pressure fluctuations of the pressure fluctuation generator within the connecting piece, whereby the pressure fluctuations in the fluid dynamic system can be minimized by destructive interference.

[0054] Furthermore, to solve the problem, a fluid dynamic system is proposed which comprises a flow or displacement machine, lines and at least one further fluid dynamic component, wherein the fluid dynamic system comprises a measuring and / or control device according to one of claims 1 to 9.

[0055] A corresponding fluid dynamic system can be operated in a particularly energy-efficient manner and with low unplanned downtime.

[0056] According to a further development, it is proposed that the pressure fluctuation generator be arranged downstream of the turbomachine or positive displacement machine, and the first pressure sensor be arranged downstream of the pressure fluctuation generator in the fluid dynamic system. This arrangement allows the active reduction of pressure fluctuations by the pressure fluctuation generator to be detected by the first pressure sensor, so that the adaptive filter can be continuously optimized accordingly.

[0057] It is further proposed that the second pressure sensor be located downstream of the fluid or displacement machine and upstream of the pressure fluctuation generator. This allows the pressure fluctuations generated by the fluid or displacement machine to be detected before they interact with the pressure fluctuations of the pressure fluctuation generator, thus enabling the generation of a reference signal.

[0058] Furthermore, to solve the problem, a method for operating a measuring and / or control device according to one of claims 1 to 9 for a fluid dynamic system is proposed, comprising the following steps: Receiving a pressure fluctuation signal from the first pressure sensor, receiving or generating a reference signal, generating a control signal from the reference signal using the adaptive filter, controlling the pressure fluctuation generator with the control signal, continuously optimizing or adjusting the adaptive filter to minimize the pressure fluctuation signal, evaluating the filter coefficients of the adaptive filter of the first control unit, and identifying changes in the fluid dynamic system from changes in the filter coefficients over time; and / or assigning these changes to known system states of the turbomachine or displacement machine and / or the fluid dynamic system and / or parts of the fluid dynamic system from the filter coefficients;and / or control of the power and / or speed of the turbo or positive displacement machine of the fluid dynamic system by evaluating the filter coefficients to find an efficient, in particular optimal, operating point, preferably the best point, of the turbo or positive displacement machine in the fluid dynamic system.

[0059] The invention is explained below with reference to preferred embodiments and the accompanying figures. Fig. 1 a fluid dynamic system with measuring and / or control device; and Fig. 2 another fluid dynamic system with measuring and / or control device.

[0060] Figure 1 Figure 1 shows a schematic representation of a fluid dynamic system 11 with a measuring and / or control device 10. Fluid dynamic systems 11 can be open or closed, as shown in the schematic representation of the Figure 1a closed fluid dynamic system 11 with a flow or displacement machine 12 in a simple circuit of pipes 13 and two symbolic further fluid dynamic components 14, for example valves, thermostats, heat exchangers, radiators, hydraulic actuators, in which the circuit is shown.

[0061] The flow or displacement machine 12 causes an increase in the static pressure in the fluid dynamic system 11 and, depending on the fluid dynamic components 14, a volume flow with a flow direction 23. The fluid dynamic system 11 can, for example, be the heating circuit of a residential building.

[0062] Pressure fluctuations are introduced into a fluid dynamic system 11, particularly by the flow or displacement machine 12. These fluctuations propagate within the fluid dynamic system 11 and excite vibrations in the structure, especially the pipes 13. This can lead to undesirable acoustic emissions, among other things.

[0063] The measuring and / or control device 10 has a pressure fluctuation generator 16 for the active reduction of pressure fluctuations, which introduces pressure fluctuations into the fluid dynamic system in a targeted manner in order to interfere destructively with the existing pressure fluctuations generated by the flow or displacement machine 12 and / or the fluid dynamic components 14.

[0064] The pressure fluctuation generator 16 is therefore hydraulically or fluid-dynamically connected to the fluid-dynamic system 11, which in the exemplary embodiment of the Figure 1 by means of an angled T-connector 24.

[0065] Downstream of the connector 24, a first pressure sensor 15 is arranged on line 13. This sensor detects pressure fluctuations and can thus determine the pressure in line 13 of the fluid dynamic system 11 over time. The pressure fluctuations are transmitted from the first pressure sensor 15 as a pressure fluctuation signal 18 to a first control unit 17.

[0066] The first control unit 17 receives the actual rotational speed 22 of the turbo or positive displacement machine 12, which is measured by a tachometer. In this embodiment, the turbo or positive displacement machine 12 has seven blades and an assumed rotational speed of 1450 revolutions per minute. The control unit 17 measures the rotational speed, multiplies it by the set number of blades, and generates a sinusoidal reference signal with a frequency of 169.2 Hz, which corresponds to the first blade pass frequency. The phase and amplitude of the sinusoidal reference signal can be preset in the control unit 17.

[0067] In this advantageous embodiment, the reference signal takes into account not only the first blade pass frequency but also the second and third blade pass frequencies. Accordingly, further sinusoidal oscillations at 338.4 Hz and 676.8 Hz are modulated into the reference signal. The phase and amplitude of the higher reference signal can assume preset values ​​in the control unit 17, with the amplitude for the second and third blade pass frequencies in the reference signal preferably being lower than the amplitude of the first blade pass frequency.

[0068] The first control unit 17 incorporates an adaptive finite impulse response filter, which filters the reference signal. Alternatively, an adaptive infinite impulse response filter, or alternatively, a combination of finite and infinite impulse response adaptive filters, is implemented. The filtered reference signal is fed as a control signal 19 to a pressure fluctuation generator 16, which is then controlled accordingly.

[0069] The pressure fluctuation generator 16 generates pressure fluctuations or pressure pulses which propagate along the wall of the line 13 and interfere in the connecting piece 24 with the pressure fluctuations in the fluid dynamic system 11, in particular with the pressure fluctuations which are induced by the flow or displacement machine 12.

[0070] The resulting pressure fluctuations are detected by the first pressure sensor 15 and transmitted to the controller unit 17 as a pressure fluctuation signal 18, thus providing feedback on the effect of the pressure fluctuation generator 16. A continuous minimization process is performed in the controller unit 17, which minimizes the pressure fluctuation signal 18 by varying the filter parameters of the digital, adaptive FIR filter within the controller unit 17. Consequently, the filter parameters are varied after a time interval according to the minimization method, for example, the mean squared error (MSA), and the result is evaluated as the pressure fluctuation signal 18. The continuous optimization of the adaptive filter also allows for adjustment to changes in the fluid dynamic system 11 in which the measuring and / or control device 10 is used.The changes in the filter behavior of the adaptive filter are used, among other things, to adjust the phase and amplitude of the back pressure or pressure fluctuations generated by the pressure fluctuation generator 16. The filter behavior of the adaptive filter is described by corresponding filter coefficients 20, which, during the continuous optimization of the adaptive filter to minimize the pressure fluctuation signal 18, describe the acoustic behavior of the fluid dynamic system 11.

[0071] Changes in or to the fluid dynamic system 11 directly affect the operating behavior of the flow or displacement machine 12 and thus the pressure fluctuations it generates. Examples of such changes include switching series or parallel pipe circuits with the fluid dynamic components 14 on and off (e.g., radiators on or off), as well as their targeted throttling by adjusting the valve position. Due to the changing system state of the fluid dynamic system 11, continuous identification of the circuit and adjustment of the control parameters in the controller unit 17 for the actuator 16 is particularly advantageous. This is achieved through the adaptive filter and the optimization process.

[0072] The filter coefficients 20 of the adaptive filter, for example parameters 1 to n, are transferred from the first control unit 17 to the second control unit 21. In possible embodiments, the first control unit 17 and the second control unit 21 can also be arranged within a common electronic processing unit.

[0073] The second control unit 21 evaluates the filter coefficients 20, thereby enabling the identification of the system state of the fluid dynamic system 11. By compensating for pressure fluctuations, the characteristic system state of the turbo or displacement machine 12 can also be evaluated and identified separately using the filter coefficients 20.

[0074] A system state, particularly a static system state, leads to a characteristic sound field at the first pressure sensor 15 and, upon cancellation, results in a characteristic set of filter weights and parameters, or filter coefficients 20. The filter coefficients 20 correspond to the canceled vibration components in the sound field. Due to its adaptive properties, the adaptive filter in the first control unit 17 adjusts the filter coefficients 20, or the filter weights and parameters, when there is a change in the sound field of the fluid dynamic system 11. The changed filter coefficients 20 therefore allow conclusions to be drawn about the changes in the fluid dynamic system 11.

[0075] In advantageous embodiments, a neural network in the second control unit 21, trained with known system states of the fluid dynamic system 11 or the turbo or positive displacement machine 12, is used to map known system states of the turbo or positive displacement machine 12 and / or the fluid dynamic system 11. By recognizing known system states, properties, and events, these can be distinguished from unknown system states, properties, and events during operation of the fluid dynamic system 11 by the measuring and / or control device 10. In this way, for example, normal and abnormal system states can be differentiated.

[0076] Furthermore, identifying the system states of the hydrodynamic system 11 and the turbo or displacement machine 12 can be used to describe the operating states of the turbo or displacement machine 12. The operating behavior of the turbo or displacement machine 12 results from its interaction with the other hydrodynamic system 11.

[0077] A positive displacement or positive displacement machine 12 always exhibits characteristic acoustic behavior when operating at its optimal point. For example, in centrifugal pumps, broadband noise increases with increasing operation outside the optimal point because the abnormal flow pattern across the pump impeller leads to additional mixing losses due to flow separation, which manifest as acoustic sources. Such changes in the characteristic acoustic behavior of a positive displacement or positive displacement machine 12 can only be detected due to the compensation of pressure fluctuations by the pressure fluctuation generator 16, which are then directly reflected in the filter coefficients 20 of the adaptive filter of the first control unit.The modified filter coefficients 20 can be evaluated in the second control unit 21 using machine learning or a neural network in such a way that, depending on the detected system state of the turbo or positive displacement machine 12, an optimal target speed 25 of the turbo or positive displacement machine 12 can be determined and output. This enables demand-based control of the turbo or positive displacement machine 12 by the second control unit 21, resulting in significant energy and cost savings during operation of the turbo or positive displacement machine 12.

[0078] Figure 2 Figure 1 shows a schematic representation of another fluid dynamic system 11 with a measuring and / or control device 10. In contrast to the exemplary embodiment of the Figure 1 The measuring and / or control device 10 of the Figure 2A second pressure sensor 26 is located downstream of the flow or displacement machine 12 and upstream of the pressure fluctuation generator 16 or the angled T-connector 24. The second pressure sensor 26 detects pressure fluctuations before they interfere with the pressure fluctuations of the pressure fluctuation generator 16 in the region of the connector 24, thereby actively reducing the pressure fluctuations. In this embodiment, the pressure fluctuations detected by the second pressure sensor 26 are received by the first control unit 17 and processed as a reference signal. Accordingly, a control signal (19) for the pressure fluctuation generator 16 is generated by the adaptive filter.

Claims

1. Measuring and / or control device (10) for a fluid-dynamic system (11), the fluid-dynamic system (11) comprising a flow or displacement machine (12), conduits (13), and at least one further fluid-dynamic component (14), the measuring and / or control device (10) comprising - at least one first pressure sensor (15), - a pressure fluctuation generator (16) for actively reducing pressure fluctuations in the fluid-dynamic system (11), - and a first control unit (17) which has an adaptive filter having a plurality of filter coefficients (20), - the first control unit (17) being designed to -- receive a pressure fluctuation signal (18) from the first pressure sensor (15), -- receive or generate a reference signal, and -- generate a control signal (19) from the reference signal by means of the adaptive filter, -- control the pressure fluctuation generator (16) using the control signal (19), -- and continuously optimize the adaptive filter in order to minimize the pressure fluctuation signal (18), characterized in that - the measuring and / or control system (10) comprises a second control unit (21) which is designed to - evaluate the filter coefficients (20) of the adaptive filter of the first control unit (17), and -- identify changes in the fluid-dynamic system (11) from changes in the filter coefficients (20) over time; and / or -- assign the filter coefficients (20) to known system states of the flow or displacement machine (12) and / or the fluid-dynamic system (11) and / or parts of the fluid-dynamic system (11); and / or -- control the power and / or speed of the flow or displacement machine (12) of the fluid-dynamic system (11) for an efficient operating point of the flow or displacement machine (12) in the fluid-dynamic system (11) by means of the evaluation of the filter coefficients (20).

2. Measuring and / or control device (10) according to claim 1, characterized in that the second control unit (21) is designed to - evaluate the filter coefficients (20) for a characteristic acoustic behavior of the flow or displacement machine (12).

3. Measuring and / or control device (10) according to either of the preceding claims, characterized in that - the second control unit (21) comprises a neural network which is trained to recognize characteristic acoustic behavior of a flow or displacement machine (12) from the filter coefficients (20).

4. Measuring and / or control device (10) according to any of the preceding claims, characterized in that the second control unit is designed to - identify a characteristic system state of the flow or displacement machine (12) from the evaluation of the filter coefficients.

5. Measuring and / or control device (10) according to any of the preceding claims, characterized in that the second control unit is designed to - identify a characteristic system state of at least one further fluid-dynamic component (14) from the evaluation of the filter coefficients.

6. Measuring and / or control device (10) according to any of the preceding claims, characterized in that the second control unit (21) is designed to - control the flow or displacement machine (12) for a particular characteristic acoustic behavior.

7. Measuring and / or control device (10) according to any of the preceding claims, characterized in that the second control unit (21) is designed to store the filter coefficients (20).

8. Measuring and / or control device (10) according to any of the preceding claims, characterized in that - the actual speed (22) of the flow or displacement machine (12) can be detected and received by the first control unit (17), the first control unit (17) being designed to generate the reference signal from the actual speed (22) of the flow or displacement machine (12).

9. Measuring and / or control device (10) according to any of claims 1 to 7, characterized in that - the measuring and / or control device (10) comprises at least one second pressure sensor (26), and - the first control unit (17) is designed to receive a second pressure fluctuation signal as a reference signal from the second pressure sensor (26).

10. Fluid-dynamic system (11) which comprises a flow or displacement machine (12), conduits (13), and at least one further fluid-dynamic component (14), characterized in that the fluid-dynamic system (11) has a measuring and / or control device (10) according to any of claims 1 to 9.

11. Fluid-dynamic system (11) according to claim 10, characterized in that the pressure fluctuation generator (16) is arranged downstream of the flow or displacement machine (12) and the first pressure sensor (15) is arranged downstream of the pressure fluctuation generator (16) in the fluid-dynamic system (11).

12. Fluid-dynamic system (11) according to claim 10 or 11, characterized in that the second pressure sensor (26) is arranged downstream of the flow or displacement machine (12) and upstream of the pressure fluctuation generator (16).

13. Method for operating a measuring and / or control apparatus (10) according to any of claims 1 to 9 for a fluid-dynamic system (11), comprising the following steps: - receiving a pressure fluctuation signal (18) from the first pressure sensor (15), - receiving or generating a reference signal, - generating a control signal (19) from the reference signal by means of the adaptive filter, - controlling the pressure fluctuation generator (16) using the control signal (19), - continuously optimizing the adaptive filter in order to minimize the pressure fluctuation signal (18), - evaluating the filter coefficients (20) of the adaptive filter of the first control unit (17), and - identifying changes in the fluid-dynamic system (11) from changes in the filter coefficients (20) over time; and / or - assigning the filter coefficients (20) to known system states of the flow or displacement machine (12) and / or the fluid-dynamic system (11) and / or parts of the fluid-dynamic system (11); and / or - controlling the power and / or speed of the flow or displacement machine (12) of the fluid-dynamic system (11) for an efficient operating point of the flow or displacement machine (12) in the hydrodynamic system (11) by means of the evaluation of the filter coefficients (20).