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DK181714B1 - System and method for detecting pressure surges - Google Patents

System and method for detecting pressure surges Download PDF

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Publication number
DK181714B1
DK181714B1 DKPA202300317A DKPA202300317A DK181714B1 DK 181714 B1 DK181714 B1 DK 181714B1 DK PA202300317 A DKPA202300317 A DK PA202300317A DK PA202300317 A DKPA202300317 A DK PA202300317A DK 181714 B1 DK181714 B1 DK 181714B1
Authority
DK
Denmark
Prior art keywords
motor
speed
detection unit
pump
magnetic field
Prior art date
Application number
DKPA202300317A
Other languages
Danish (da)
Inventor
Kühne Eva
Original Assignee
Ewa Sensors Aps
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ewa Sensors Aps filed Critical Ewa Sensors Aps
Priority to DKPA202300317A priority Critical patent/DK181714B1/en
Priority to PCT/DK2024/050086 priority patent/WO2024213216A1/en
Application granted granted Critical
Publication of DK181714B1 publication Critical patent/DK181714B1/en
Publication of DK202300317A1 publication Critical patent/DK202300317A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H1/00—Measuring characteristics of vibrations in solids by using direct conduction to the detector
    • G01H1/003—Measuring characteristics of vibrations in solids by using direct conduction to the detector of rotating machines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
    • F04D15/0077—Safety measures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
    • F04D15/0077—Safety measures
    • F04D15/0083—Protection against sudden pressure change, e.g. check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
    • F04D15/0088—Testing machines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D1/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2270/00—Control
    • F05D2270/80—Devices generating input signals, e.g. transducers, sensors, cameras or strain gauges
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2270/00—Control
    • F05D2270/80—Devices generating input signals, e.g. transducers, sensors, cameras or strain gauges
    • F05D2270/807—Accelerometers

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Control Of Non-Positive-Displacement Pumps (AREA)
  • Control Of Positive-Displacement Pumps (AREA)

Abstract

A method for monitoring water hammer (10) in an environment (20) comprising at least one pump (4) having an electrical induction motor (8) is disclosed. The at least one pump (4) is in fluid communication with a number of pipes (12, 12') and configured to pump a media (18), wherein the method comprises the step of detecting: a) the synchronous speed (ꞶB) of the magnetic field of the motor (8) and b) the rotational speed (ꞶM) of the motor (8). The method comprises the following steps: - for a predefined time period, on the basis of the detected synchronous speed (ꞶB(t)) of the magnetic field of the motor (8) and the rotational speed (ꞶM(t)) of the motor (8) calculating the slip speed (S(t)) of the motor (8) as function of time (t), wherein the slip speed (S(t)) is defined as the difference between the synchronous speed (ꞶB(t)) of the magnetic field of the motor (8) and the rotational speed (ꞶM(t)) of the motor (8): (2) S(t) = (ꞶB(t) - ꞶM(t)) / ꞶB - determining the alternating portion (A1(t)) of the slip speed (S(t)); - analysing the alternating portion (A1(t)) of the slip speed (S(t)) and concluding that water hammer (10) is present in one of the pipes (12, 12') if: a) the alternating portion (A1(t), A2(t), A3(t)) of the slip speed (S(t)) comprises three spaced apart positive peaks (P1, P3, P5), wherein the time (t1) between the first positive peak (P1) and the second positive peak (P3) is larger than the time (t2) between the second positive peak (P2) and the third positive peak (P5) and b) the first positive peak (P1) is larger than the second positive peak (P3) and the second positive peaks (P3) is larger than the third positive.

Description

DK 181714 B1 1
Field of invention
The present invention relates to a method for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor, wherein the at least one pump is in fluid communication with a number of pipes and configured to pump a media. The present invention also relates to a water hammer detection system for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor, wherein the at least one pump is in fluid communication with a number of pipes and configured to pump a media.
Prior art
Water hammer is a pressure surge or wave, caused when a fluid in motion is forced to stop or change direction suddenly - a momentum change.
This phenomenon commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe.
This pressure wave can cause major problems, from noise and vibration to pipe rupture or collapse.
In electrical induction motors the slip speed is the difference between an electrical induction motor's synchronous and asynchronous speed e.g. measured as revolutions per minute (RPM). The synchronous speed is the speed of the revolution of the magnetic field in the stator winding of the motor. The asynchronous speed is the rotating speed of the motor shaft.
Typically, the slip speed S is defined as the difference between the rotational speed of the motor øm and the synchronous speed ws of the magnetic fields of the motor: This can be defined as: (1) S = (ws - Om)
DK 181714 B1 2
When the rotor is not turning the slip speed S is 0 RPM. Full-load slip speed, however, is typically in the rage between 30-60 RPM.
The prior art methods and systems for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor are rather complex and expensive. Moreover, the prior art solutions are not capable of distinguishing between water hammer and vibrations that are not related to water hammer. Accordingly, there is a need for a method and a system which reduces or even eliminates the above mentioned disadvantages of the prior art.
US 20170248142 Al discloses a method for detecting faults or operational parameters in a pump assembly by use of a handheld communication device is described. The pump assembly includes an electric motor and a pump, wherein the pump assembly or electric motor has at least one rotating shaft The method comprises the steps of: a) contactless measuring a sound signal emanating from the pump assembly by use of a microphone connected to or implemented in the handheld communication device, b) processing the measured sound signal, and c) recognising one or more sound emanating condition including any possible faults by way of the processed sound signal. It would be desirable to have an alternative solution that is simpler and cheaper.
US 20200182684 Al discloses a system for continuously monitoring at least one machine including a plurality of magnetic sensors synchronously sensing magnetic fields emitted by at least one machine.
The plurality of magnetic sensors are sensing the magnetic fields along a corresponding plurality of channels and outputting magnetic field emission signals corresponding to the magnetic fields. A signal analyser is receiving at least a portion of the magnetic field emission signals and performing analysis of the magnetic field emission signals. The signal
DK 181714 B1 3 analyser is providing an output based on the analysis, wherein the output includes at least an indication of a condition of the at least one machine.
A control module is receiving the indication of the condition and initiating at least one of a repair event on the at least one machine. An adjustment to a maintenance schedule of the at least one machine and an adjustment to an operating parameter of the at least one machine based on the indication. It would be desirable to have an alternative solution that is simpler and cheaper.
It is an object of the invention to provide an alternative to the than the prior art solutions by providing a simpler and cheaper system and method for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor.
It is also an object to the invention to provide a system and a method that is capable of distinguishing between water hammer and vibrations that are not related to water hammer.
Summary of the invention
The object of the present invention can be achieved by a method as defined in claim 1 and by a system as defined in claim 9. Preferred embodiments are defined in the dependent subclaims, explained in the following description and illustrated in the accompanying drawings.
The method according to the invention is a method for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor, wherein the at least one pump is in fluid communication with a number of pipes and configured to pump a media, wherein the method comprises the step of detecting: a) the synchronous speed ws of the magnetic field of the motor and b) the rotational speed om of the motor, wherein the method comprises the following steps:
DK 181714 B1 4 - for a predefined time period, on the basis of the detected synchronous speed we(t) of the magnetic field of the motor and the rotational speed am(t) of the motor calculating the slip speed S(t) of the motor as function of time, wherein the slip speed S(t) is defined as the difference between the synchronous speed øs(t) of the magnetic field of the motor and the rotational speed om(t) of the motor: (2) S(t) = ws(t) - om(t) - determining an alternating portion A(t) of the slip speed S(t); - analysing the alternating portion Ai(t) of the slip speed S(t) and concluding that water hammer is present in one of the pipes if: a) the alternating portion Ai(t) of the slip speed S(t) comprises three spaced apart positive peaks (Pi, P3, Ps), wherein the time (ti) between the first positive peak Pi; and the second positive peak Ps is larger than the time (tz) between the second positive peak Ps and the third positive peak Ps and b) the first positive peak Pi is larger than the second positive peak Ps and the second positive peak Ps is larger than the third positive peak Ps.
Hereby, it is possible to provide a simpler and cheaper method than the prior art solutions. It is also possible to provide a method that is capable of distinguishing between water hammer and vibrations that are not related to water hammer.
In an embodiment, the method comprises: a) determining if the alternating portion A; is repeated or not and b) if the alternating portion A(t) is repeated it is concluded that water hamming is occurring.
In an embodiment, the method determines if the alternating portion A; is repeated within a predefined time from a previous alternating portion
Ai. In an embodiment, the predefined time is in the range 0.01-10 times
DK 181714 B1 the duration of the previous alternating portion Ai. In an embodiment, the predefined time is in the range 0.02-5 times the duration of the previous alternating portion Ai. In an embodiment, the predefined time is in the range 0.2-3 times the duration of the previous alternating portion 5 Ai.
The method is suitable for detecting water hammer in an environment comprising at least one pump having an electrical induction motor. The method is suitable for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor.
At least one pump is in fluid communication with a number of pipes and configured to pump a media. The pump would typicall be connected to an inlet pipe that delivers the media to be pumped. The pump would typically be connected to an outlet pipe receiving media that is pressurised by the pump.
The method comprises the step of detecting the synchronous speed ws of the magnetic field of the motor. In an embodiment, this step is carried out by applying a non-invasively installed detection unit. In an embodiment, the detection unit comprises a sensor configured to detect a magnetic field.
The method comprises the step of detecting the rotational speed am of the motor, In an embodiment, this step is carried out by applying a non- invasively installed detection unit. In an embodiment, the detection unit comprises a sensor configured to detect vibrations. In this embodiment, the system is configured to determine the rotational speed om of the motor on the basis of detected vibration data.
The method comprises the step of, for a predefined time period, on the basis of the detected synchronous speed ws(t) of the magnetic field of the
DK 181714 B1 6 motor and the rotational speed om(t) of the motor calculating the slip speed S(t) of the motor as function of time.
The slip speed S(t) is defined as the difference between the synchronous speed we(t) of the magnetic field of the motor and the rotational speed om(t) of the motor: (2) S(t) = øs(t) - om(t)
The method comprises the step of, for a predefined time period, on the basis of the detected synchronous speed øs(t) of the magnetic field of the motor and the rotational speed ww(t) of the motor determining the alternating portion Ai(t) of the slip speed S(t).
The method comprises the step of analysing an alternating portion Ax (t) of the slip speed S(t) and concluding that water hammer is present in one of the pipes if: a) the alternating portion Ai(t) of the slip speed S(t) comprises three spaced apart positive peaks Pi, Ps, Ps, wherein the time ti between the first positive peak Pi and the second positive peak Ps is larger than the time t: between the second positive peak Ps and the third positive peak Ps and b) the first positive peak Pi is larger than the second positive peak Ps and the second positive peak Ps is larger than the third positive peak Ps.
The peaks can be detected by using any suitable peak detection technique. In an embodiment, the peak detection technique applies the fact that the first derivative of a peak has a downward-going zero- crossing at the peak maximum. To avoid false zero-crossing due to the noise, it is possible to: a) first smooth the first derivative of the signal, before looking for downward-going zero-crossings, and
DK 181714 B1 7 b) take only those zero crossings whose slope exceeds a certain predetermined minimum (slope threshold) at a point where the original signal exceeds a certain minimum (amplitude threshold).
By adjusting the smooth width, slope threshold, and amplitude threshold, it is possible to detect only the desired peaks and ignore peaks that are too small, too wide, or too narrow.
In an embodiment, the method comprises the step of determining the mean value of the slip speed S(t), wherein the alternating portion A(t) of the slip speed S(t) is determined by subtracting the mean value of the slip speed S(t) from the slip speed S(t).
In an embodiment, the method comprises the step of applying a detection unit that is attached to the motor of the pump, wherein the detection unit is configured to measure the magnetic field of a stator of the motor and hereby determine the synchronous speed we of the magnetic field of the motor.
In an embodiment, the method comprises the step of applying a detection unit that is attached to the motor of the pump, wherein the detection unit is configured to detect vibrations and hereby determine the rotational speed ov of the motor.
In an embodiment, the detection unit that is detachably attached to the motor of the pump.
In an embodiment, the detection unit is attached to the motor of the pump by using mechanical fastening structures including bolts, a hose clamp, or a mounting bracket.
In an embodiment, the motor comprises a motor shaft, wherein the detection unit is configured to, on the basis of the vibrations detected by the detection unit, determine the rotational speed om of the motor shaft.
DK 181714 B1 8
Determination of the rotational speed øm of the motor shaft may be carried out by using prior art technique disclosed in US 11009520 B2 or in the article "A Method for Estimation of Motor Rotational Speed from
STFT Spectrogram at a Non-stationary Conditions” IFAC-PapersOnLine
Volume 51, Issue 6, 2018, Pages 283-288.
In an embodiment, the method comprises the step of determining that a foreign body is in the pumped media if: a) the alternating portion A(t), A>(t), As(t) comprises a U-shaped peak having a peak level that is larger than three times the average of the alternating portion A(t), A>(t), As(t) outside the U-shaped peak.
In an embodiment, the area below a single U-shaped positive peak having a duration tz is more than 10 times the area below any adjacent signal for a time corresponding to two times the duration ts.
In an embodiment, the method comprises the step of determining that gravel is in the pumped media (18) if the variance of the alternating portion Ai(t), A>(t), As(t) is larger than three times the average of the alternating portion A(t), A>(t), As(t).
In an embodiment, the detection unit comprises a communication module configured to wirelessly transmit detected data.
In an embodiment, the detection unit comprises a housing, wherein an accelerometer and a coil assembly is provided in the housing.
In an embodiment, coil assembly is configured to determine the amplitude of the magnetic field of the motor.
DK 181714 B1 9
In an embodiment, coil assembly is configured to determine the direction of the magnetic field of the motor.
In an embodiment, coil assembly is configured to determine the direction of the magnetic field in two dimensions.
In an embodiment, coil assembly is configured to determine the direction of the magnetic field in three dimensions.
In an embodiment, a communication module is provided in the housing.
The water hammer detection system for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor, wherein the at least one pump is in fluid communication with a number of pipes and configured to pump a media, wherein the system comprises a detection unit arranged and configured for detecting: a) the synchronous speed wg of the magnetic field of the motor and b) the rotational speed om of the motor, wherein the system is configured to: - for a predefined time period, on the basis of the detected synchronous speed we(t) of the magnetic field of the motor and the rotational speed wm(t) of the motor calculate the slip speed S(t) of the motor as function of time t, wherein the slip speed S(t) is defined as the difference between the synchronous speed ws(t) of the magnetic field of the motor and the rotational speed øm(t) of the motor: (2) S(t) = ws(t) - om(t) - determine the alternating portion A(t) of the slip speed S(t); - analyse the alternating portion Ai(t) of the slip speed S(t) and concluding that water hammer is present in one of the pipes if: a) the alternating portion Ai(t) of the slip speed S(t) comprises three spaced apart positive peaks Pi, Ps, Ps, wherein the time ti between the first positive peak Pi and the second
DK 181714 B1 10 positive peak Ps is larger than the and the time t> between the second positive peak Ps and the third positive peak Ps and b) the first positive peak Pi is larger than the second positive peak Ps and the second positive peak Ps is larger than the third positive peak Ps.
Hereby, it is possible to provide a simpler and cheaper system than the prior art solutions. It is also possible to provide a system that is capable of distinguishing between water hammer and vibrations that are not related to water hammer.
In an embodiment, the system is configured to: a) determine if the alternating portion A; is repeated or not and b) if the alternating portion Ai(t) is repeated it is concluded that water hamming is occurring.
In an embodiment, the system is configured to determine if the alternating portion A; is repeated within a predefined time from a previous alternating portion Ai. In an embodiment, the predefined time is in the range 0.01-10 times the duration of the previous alternating portion Ai. In an embodiment, the predefined time is in the range 0.02- 5 times the duration of the previous alternating portion Ai. In an embodiment, the predefined time is in the range 0.2-3 times the duration of the previous alternating portion Aj.
The system is suitable of detecting water hammer in an environment comprising at least one pump having an electrical induction motor. The system is suitable for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor.
The system according to the invention is a water hammer detection
DK 181714 B1 11 system for monitoring water hammer in an environment comprising at least one pump having an electrical induction motor, wherein the at least one pump is in fluid communication with a number of pipes and configured to pump a media.
In an embodiment, the media is a water containing media. In an embodiment, the media is water.
The system comprises a detection unit arranged and configured for detecting: a) the synchronous speed wg of the magnetic field of the motor and b) the rotational speed om of the motor.
In an embodiment, the detection unit comprises a vibration sensor.
In an embodiment, the detection unit comprises a magnetic field sensor.
The system is configured to: - for a predefined time period, on the basis of the detected synchronous speed we(t) of the magnetic field of the motor and the rotational speed wm(t) of the motor calculate the slip speed S(t) of the motor as function of time t, wherein the slip speed S(t) is defined as the difference between the synchronous speed ws(t) of the magnetic field of the motor and the rotational speed øm(t) of the motor: (2) S(t) = øs(t) - om(t)
The system is configured to determine the alternating portion A(t) of the slip speed S(t).
The system is configured to analyse the alternating portion A:(t) of the slip speed S(t) and concluding that water hammer is present in one of the pipes if:
DK 181714 B1 12 a) the alternating portion Ai(t) of the slip speed S(t) comprises three spaced apart positive peaks Pi, Ps, Ps, wherein the time ti between the first positive peak Pi and the second positive peak Ps is larger than the time t> between the second positive peak Ps and the third positive peak Ps i and b) the first positive peak Pi is larger than the second positive peak Ps and the second positive peak Ps is larger than the third positive peak Ps.
In an embodiment, the system is configured to determine the mean value of the slip speed S(t), wherein the alternating portion Ai(t) of the slip speed S(t) is determined by subtracting the mean value of the slip speed
S(t) from the slip speed S(t).
In an embodiment, the detection unit is attached to the motor of the pump, wherein the detection unit is configured to measure the magnetic field of a stator of the motor and hereby determine the synchronous speed ws of the magnetic field of the motor.
In an embodiment, the detection unit is attached to the motor of the pump, wherein the detection unit is configured to detect vibrations and hereby determine the rotational speed øm of the motor.
In an embodiment, the detection unit is detachably attached to the motor of the pump.
In an embodiment, the motor comprises a motor shaft, wherein the wherein the detection unit is configured to, on the basis of the detected vibrations determine the rotational speed wm of the motor shaft.
In an embodiment, the system is configured to determine that a foreign body is in the pumped media if:
DK 181714 B1 13 a) the alternating portion A(t), A>(t), As(t) comprises a U-shaped peak having a peak level that is larger than three times the average of the alternating portion A(t), A>(t), As(t) outside the U-shaped peak.
In an embodiment, the system is configured to determine that gravel is in the pumped media if the variance of the alternating portion (A(t),
A>(t), As(t)) is larger than three times the average of the alternating portion (A1(t), A>(t), As(t)).
In an embodiment, the detection unit comprises a communication module configured to wirelessly transmit detected data.
In an embodiment, the detection unit comprises a housing, wherein an accelerometer and a coil assembly is provided in the housing.
In an embodiment, coil assembly is configured to determine the amplitude of the magnetic field of the motor.
In an embodiment, coil assembly is configured to determine the direction of the magnetic field of the motor.
In an embodiment, coil assembly comprises two coils arranged and configured to determine the direction of the magnetic field of the motor.
In an embodiment, coil assembly comprises three coils arranged and configured to determine the direction of the magnetic field of the motor.
In an embodiment, a communication module is provided in the housing.
In an embodiment, the detection unit comprises a tachometer arranged and configured to measure the rotation speed of the shaft of the motor.
DK 181714 B1 14
In an embodiment, a tachometer is arranged in the housing. By using the tachometer, which is also known as a revolution-counter or RPM gauge, it is possible to measure the rotation speed of the shaft of the motor.
In an embodiment, at least one Hall effect sensor is arranged in the housing. Hereby, it is possible to detect the presence and magnitude of the magnetic field of the motor.
Description of the Drawings
The invention will become more fully understood from the detailed description given herein below. The accompanying drawings are given by way of illustration only, and thus, they are not limitative of the present invention. In the accompanying drawings:
Fig. 1 shows a schematic view of a system according to the invention;
Fig. 2 shows two curves depicting the synchronous speed ws of the magnetic fields of the motor and the rotational speed wm of the motor as function of time t;
Fig. 3A shows the alternating portion A(t) of the slip speed S(t) as function of time t in a situation, in which water hammer is occurring;
Fig. 3B shows the alternating portion A(t) of the slip speed S(t) as function of time t in a situation, in which a foreign body is in the media being pumped by the pump;
Fig. 3C shows the alternating portion As(t) of the slip speed S(t) as function of time t in a situation, in which gravel is in the pumped media;
Fig. 4 shows a flowchart illustrating the steps of a method according to the invention;
Fig. 5A shows a pipe 12 with no flowing media due to a closed valve;
Fig. 5B shows the pipe 12 shown in Fig. 5A, in a configuration in
DK 181714 B1 15 which the media is flowing through the open valve;
Fig. 5C shows the pipe 12 shown in Fig. 5B, in a configuration in which water hammer occurs when the valve is being closed;
Fig. 6 shows a system according to the invention;
Fig. 7A shows a detection unit according to the invention and
Fig. 7B shows another detection unit according to the invention.
Detailed description of the invention
Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, a system 2 of the present invention is illustrated in Fig. 1.
Fig. 1 illustrates a water hammer detection system 2 for monitoring water hammer in an environment 20. The environment 20 comprises at a pump 4 having an electrical induction motor 8. The pump 4 is in fluid communication with an inlet pipe 12’ and an outlet pipe 12. The pump 4 is arranged and configured to pump a media. The media will typically be a liquid, preferably a water-containing liquid. In an embodiment, the pump 4 is arranged and configured to pump sewage water.
The system 2 comprises a detection unit 24 arranged and configured to detect: a) the synchronous speed ws(t) of the magnetic field of the motor 8 and b) the rotational speed om(t) of the motor 8.
The system 2 is configured to for a predefined time period, on the basis of the detected synchronous speed ws(t) of the magnetic field of the motor 8 and the rotational speed wm(t) of the motor 8 calculate the slip speed S(t) of the motor 8 as function of time (t).
The slip speed S(t) is defined as the difference between the synchronous speed ws(t) of the magnetic field of the motor 8 and the rotational speed
DK 181714 B1 16 om(t) of the motor 8. Accordingly, the slip speed can be defined by the following equation S(t): (2) S(t) = ws(t) - om(t)
The detection unit 24 is configured to determine the alternating portion
A1(t) of the slip speed S(t) by calculating the mean value of the slip speed
S(t) by using of a filter 16.
Fig. 1 illustrates that the slip speed S(t) of the motor 8 as S as function of time (t) can be split into two components: - A mean value Cand - An alternating A(t).
Fig. 2 illustrates a first curve depicting the synchronous speed ws (frequency F) of the magnetic fields of the motor as function of time t.
Fig. 2 also illustrates a second curve depicting the rotational speed om (frequency F) of the motor as function of time t. The mean value C of the slip speed (the difference between the synchronous speed wg of the magnetic fields of the motor and the rotational speed wm of the motor is indicated.
Fig. 3A illustrates the alternating portion Ai(t) of the slip speed S(t) as function of time t in a situation, in which water hammer is occurring.
A first condition is fulfilled since: a) the alternating portion Ai(t) of the slip speed S(t) comprises three spaced apart positive peaks Pi, Ps, Ps, wherein Py > P3 > Ps b) the time ti between the first positive peak Pi; and the second positive peak Pz is larger than the time t; between the second positive peak P3 and the third positive peak Ps.
Since these two conditions are fulfilled, the system and method according
DK 181714 B1 17 to the invention will conclude that water hammer is present. However, for ensuring that the water hammer is present is determined if the signature of the alternating portion Ai(t) is repeated. Since this is the case, it can be concluded that water hammer is present.
It can be seen that the water hammer signature is repeated. In an embodiment, the method takes advantage of this by requiring repetition of the signature as a criterion when it should be determined that water hammer is present.
Fig. 3B illustrates the alternating portion Ax(t) of the slip speed S(t) as function of time t in a situation, in which a foreign body is in the media being pumped by the pump. The alternating portion A>(t) contains a U- shaped positive peak having a peak level Ls that is larger than three times the RMS of the alternating portion A(t) outside the U-shaped peak.
The U-shaped positive peak has a duration t:. The area below a single
U-shaped positive peak is more than 10 times the area below any adjacent signal for a time corresponding to two times the duration ts.
Fig. 3C illustrates the alternating portion As(t) of the slip speed S(t) as function of time t in a situation, in which gravel is in the pumped media.
The variance of the alternating portion As(t) is larger than three times the RMS of the alternating portion Az(t). The alternating portion As(t) contains a series of peaks having peak levels Ls, Ly, Ls that are larger than the amplitude Ls of the remaining portion of the alternating portion
As(t).
Fig. 4 illustrates a flowchart illustrating the steps of a method according to the invention. The first step the synchronous speed ws(t) of the magnetic field of the motor 8 and the rotational speed am(t) of the motor 8 is provided.
DK 181714 B1 18
In the next step the slip speed S(t) of the motor 8 as function of time t is calculated by using the formula: (2) S(t) = we(t) - om(t)
In the next step, the alternating portion Ai(t) of the slip speed S(t) is determined and analyses.
In the next step is determined if the alternating portion A(t) of the slip speed S(t) comprises several spaced apart positive peaks Pi, P3, Ps, wherein the time ti, tz between adjacent positive peaks Pi, P3, Ps fulfills that ti: > to. If this condition is not fulfilled, the first method will start over from the initial step. If, on the other hand, this condition is fulfilled, the method will continue to the next step, in which it is determined if the part of the level Lz of the first of said positive peaks P1 is at least three times as large as the level Li of the part of the alternating portion Ai(t) of the slip speed S(t) that contains none of said positive peaks P1, P3, Ps. If this condition is not fulfilled, the first method will start over from the initial step. If, on the other hand, this condition is fulfilled, it is concluded that a pressure shockwave is present:
Accordingly, the conditions for water hamming are present. In order to ensure that water hamming is occurring it is, however, determined if the alternating portion A1(t) is repeated or not. If the alternating portion
Ai(t) is repeated (like shown in and explained with reference to Fig. 3A) it can be concluded that water hamming is occurring.
Fig. 5A illustrates a pipe 12 with no flowing media 18 because the valve 14 is closed.
Fig. 5B illustrates the pipe 12 shown in Fig. 5A, in a configuration in which the media 18 is flowing through the open valve 14. The direction of the
DK 181714 B1 19 media 18 is indicated with arrows.
Fig. 5C illustrates the pipe 12 shown in Fig. 5B, in a configuration in which water hammer 10 occurs when the valve 14 is being closed.
Fig. 6 illustrates a system 2 according to the invention. The system 2 comprises a rotatory machine 4 that is mechanically connected to a floor 34. The rotatory machine is a pump 4 comprises a motor 8 provided with a motor shaft 22. The motor 8 is arranged and configured to rotate a pump shaft 15 of a pump that is driven by the motor 8.
The pump shaft 15 is connected to the motor 8 via a coupling 11.
The system 2 comprises a detection unit 24 placed on the motor 8 of the first rotatory machine 4. The detection unit 24 is configured to be attached to and hereby detect vibration data 28 of the rotatory machine 4,
The system 2 comprises a processing unit 32 configured to receive and process said data 28. The processing unit 32 may be contained in a web- based server accessible via the Internet 30. In an embodiment, the processing unit 32 is integrated in the detection unit 24. In an embodiment, the processing unit 32 is integrated in an external device (e.g. a laptop computer or a tablet that is communicatively connected to the detection unit 24).
The rotatory machine 4 is mechanically connected to the floor 34 via a base member 20 placed on the floor 34.
The system 2 is designed for monitoring water hammer in an environment comprising the rotary machine 4 formed as a pump.
The pump housing 17 is connected to and receives a media to be pumped
DK 181714 B1 20 via an inlet pipe 12’. The pump housing 17 is connected to and pumps the media out through an outlet pipe 12.
It is important to underline that the pump 4 may be different from the ones shown in Fig. 1. In an embodiment, the rotatory machine(s) are pumps, wherein the motor and the pump are joint (built together or integrated). In an embodiment, the rotatory machine(s) are pumps, wherein the motor of the pump is fixed the pump housing of the pump.
The detection unit 24 may be attached to any suitable structure of the motor 8. The attachment may be established by using any suitable mechanical fastening structures including bolts, a hose clamp, or a mounting bracket.
Fig. 7A illustrates a detection unit 24 according to the invention. The detection unit 24 comprises a housing 40 configured to be attached to a motor of a pump. The detection unit 24 comprises a battery 42 for providing electrical power to the detection unit 24. The detection unit 24 comprises a printed circuit board 44 provided with a communication module 36. The communication module 36 is configured to communicate wirelessly with an external device (e.g. via a local network). In an embodiment, the detection unit 24 comprises a modem configured for sending digital data wirelessly. In an embodiment, detection unit 24 comprises a Bluetooth radio module with built-in antenna.
The detection unit 24 comprises an accelerometer 38 arranged and configured to detect vibrations of the detection unit 24. Accordingly, when the detection unit 24 is attached to a motor, the accelerometer 38
Ci capable of detecting the vibrations of the motor. In an embodiment, the accelerometer 38 is a multi-axis accelerometer configured to detect both the magnitude and the direction of the proper acceleration, as a vector quantity. In an embodiment, the accelerometer 38 is a two-axis
DK 181714 B1 21 accelerometer. In an embodiment, the accelerometer 38 is a three-axis accelerometer. In an embodiment, the accelerometer 38 is a single-axis accelerometer 38.
In an embodiment, the accelerometer 38 is a micromachined microelectromechanical systems (MEMS).
In an embodiment, the detection unit 24 comprises a control unit. In an embodiment, the control unit comprises a processing unit.
The detection unit 24 comprises a coil assembly 60 arranged and configured to detect the magnetic field of a motor to which the detection device is attached. In an embodiment, the coil assembly 60 comprise one or more coils arranged and configured to detect the direction and magnitude of the magnetic field of the motor. In an embodiment, the coil assembly 60 comprise two coils arranged and configured to detect the direction and magnitude of the magnetic field of the motor. In an embodiment, the coil assembly 60 comprise three coils arranged and configured to detect the direction and magnitude of the magnetic field of the motor.
Fig. 7B illustrates another detection unit according to the invention. The detection unit 24 comprises a housing 40 configured to be attached to a rotatory machine such as a pump or motor. The detection unit 24 comprises a power supply 46 connected to a power cable 48 protruding from the housing 40.
The detection unit 24 comprises a printed circuit board 44 provided with a communication module 36. The communication module 36 is connected to an external device by using a data cable 52. The data cable 52 may be electronically connected to a control box of rotatory machine (e.g. a pump). In an embodiment, the detection unit 24 comprises no communication module but is electrically connected to an external
DK 181714 B1 22 communication module (e.g. built into an external device such as a control box of a pump or a motor).
The detection unit 24 comprises an accelerometer 38 corresponding to the one shown and explained with reference to Fig. 7A. In an embodiment, the detection unit 24 comprises a control unit. In an embodiment, the control unit comprises a processing unit. The detection unit 24 comprises a coil assembly 60 arranged and configured to detect the magnetic field of a motor to which the detection device is attached.
In an embodiment, the coil assembly 60 comprise one or more coils arranged and configured to detect the direction and magnitude of the magnetic field of the motor. In an embodiment, the coil assembly 60 comprise two coils arranged and configured to detect the direction and magnitude of the magnetic field of the motor. In an embodiment, the coil assembly 60 comprise three coils arranged and configured to detect the direction and magnitude of the magnetic field of the motor.
DK 181714 B1 23
List of reference numerals 2 System 4 Pump 6 Motor shaft 8 Motor
Water hammer 11 Coupling 10 12, 12’ Pipe 14 Valve
Pump shaft 16 Filter 17 Pump housing 15 18 Pumped media (e.g. water)
Environment 21 Base member 22 Motor shaft 24 Detection unit 20 28 Data (e.g. sent as wireless signals) 30 Internet 32 Processing unit 36 Communication module 38 Accelerometer 40 Housing 42 Battery 44 Printed circuit board 46 Power supply 48 Power cable 52 Data cable 60 Coil assembly
S Slip speed
DK 181714 B1 24
OB Synchronous speed of the magnetic fields of the motor (OM Rotational speed of the motor (the asynchronous speed) we (t) Synchronous speed of the magnetic fields of the motor as function of time om (t) Rotational speed of the motor as function of time t Time ti Time
F Frequency (e.g. revolutions per minute, RPM)
C Mean value
Li, Lo Level
Ls, La Level
Ls, Le Level
L7, Ls Level
A(t) Alternating part of the slip speed as function of time
A>(t) Alternating part of the slip speed as function of time
As(t) Alternating part of the slip speed as function of time t2 Duration
Pi Peak
P3 Peak
Ps Peak

Claims (16)

DK 181714 B1 25 PatentkravDK 181714 B1 25 Patent claim 1. Fremgangsmåde til overvågning af trykstgd (10) i et miljø (20) omfattende mindst én pumpe (4) med en elektrisk induktionsmotor (8), hvor den mindst ene pumpe (4) står i fluidforbindelse med et antal rør (12, 127) og er konfigureret til at pumpe et medium (18), hvor fremgangsmåden omfatter trinnet med detektering af: a) den synkrone hastighed (wg) for motorens (8) magnetfelt og b) motorens (8) omdrejningshastighed (am), hvor fremgangsmåden omfatter følgende trin: - i et foruddefineret tidsrum, på basis af den detekterede, synkrone hastighed (ws(t)) for motorens (8) magnetfelt og motorens (8) omdrejningshastighed (om(t)) at beregne motorens (8) sliphastighed (S(t)) som en funktion af tid (t), hvor sliphastigheden (S(t)) defineres som forskellen mellem den synkrone hastighed (ws(t)) for motorens (8) magnetfelt og motorens (8) omdrejningshastighed (øm(t)): (2) S(t) = øs(t) - w(t), kendetegnet ved, at fremgangsmaden omfatter: - bestemmelse af en vekslende del (A(t), A(t), As(t)) af sliphastigheden (S(t)); - analyse af den vekslende del (A:(t), A>(t), As(t)) af sliphastigheden (S(t)) og at konkludere, at trykstød (10) er til stede i ét af rørene (12, 127), hvis: a) den vekslende del (Ai(t), A>(t), As(t)) af sliphastigheden (S(t)) omfatter tre adskilte, positive toppe (Pi, Ps, Ps), hvor tiden (ti) mellem den første positive top (P1) og den anden positive top (Ps) er længere end tiden (t2) mellem den anden positive top (Pl) og den tredje positive top (Ps) og b) den første positive top (Pi) er større end den anden positive top (Ps), og den anden positive top (Ps) er større end den tredje positive top (Ps).1. Method for monitoring pressure stgd (10) in an environment (20) comprising at least one pump (4) with an electric induction motor (8), where the at least one pump (4) is in fluid communication with a number of pipes (12, 127 ) and is configured to pump a medium (18), the method comprising the step of detecting: a) the synchronous speed (wg) of the motor (8) magnetic field and b) the rotational speed (am) of the motor (8), the method comprising following steps: - in a predefined period of time, on the basis of the detected synchronous speed (ws(t)) of the motor (8) magnetic field and the motor (8) rotational speed (rpm(t)) to calculate the slip speed of the motor (8) (S (t)) as a function of time (t), where the slip speed (S(t)) is defined as the difference between the synchronous speed (ws(t)) of the motor (8) magnetic field and the motor (8) rotational speed (øm(t) )): (2) S(t) = øs(t) - w(t), characterized in that the procedure includes: - determination of an alternating part (A(t), A(t), As(t)) of the slip velocity (S(t)); - analysis of the alternating part (A:(t), A>(t), As(t)) of the slip velocity (S(t)) and to conclude that pressure shock (10) is present in one of the tubes (12 , 127), if: a) the alternating part (Ai(t), A>(t), As(t)) of the slip velocity (S(t)) includes three distinct, positive peaks (Pi, Ps, Ps), where the time (ti) between the first positive peak (P1) and the second positive peak (Ps) is longer than the time (t2) between the second positive peak (Pl) and the third positive peak (Ps) and b) the first positive peak (Pi) is greater than the second positive peak (Ps), and the second positive peak (Ps) is greater than the third positive peak (Ps). DK 181714 B1 26DK 181714 B1 26 2. Fremgangsmåde ifølge krav 1, hvor fremgangsmåden omfatter trinnet med bestemmelse af middelværdien (C) af sliphastigheden (S(t)), hvor den vekslende del (Ai(t), A(t), As(t)) af sliphastigheden (S(t)) bestemmes ved at trække middelværdien (C) af sliphastigheden (S(t)) fra sliphastigheden (S(t)).2. Method according to claim 1, wherein the method comprises the step of determining the mean value (C) of the slip velocity (S(t)), where the alternating part (Ai(t), A(t), As(t)) of the slip velocity ( S(t)) is determined by subtracting the mean (C) of the slip velocity (S(t)) from the slip velocity (S(t)). 3. Fremgangsmåde ifølge krav 1 eller 2, hvor fremgangsmåden omfatter trinnet med at anvende en detekteringsenhed (24), der er fastgjort til pumpens (8) motor (4), hvor detekteringsenheden (24) er konfigureret til at: a) måle magnetfeltet for en stator i motoren (8) og derved bestemme den synkrone hastighed (ws) for motorens (8) magnetfelt og b) detektere vibrationer og derved bestemme motorens (8) omdrejningshastighed (am). 3. Method according to claim 1 or 2, wherein the method comprises the step of using a detection unit (24) attached to the motor (4) of the pump (8), wherein the detection unit (24) is configured to: a) measure the magnetic field of a stator in the motor (8) thereby determining the synchronous speed (ws) of the magnetic field of the motor (8) and b) detecting vibrations and thereby determining the rotational speed (am) of the motor (8). 4, Fremgangsmåde ifølge krav 3, hvor motoren (4) omfatter en motoraksel (6), hvor detekteringsenheden (24) er konfigureret til på basis af de detekterede vibrationer at bestemme motorakslens (6) omdrejningshastigheden (om).4, Method according to claim 3, wherein the motor (4) comprises a motor shaft (6), wherein the detection unit (24) is configured to determine, on the basis of the detected vibrations, the rotational speed (rpm) of the motor shaft (6). 5. Fremgangsmåde ifølge et hvilket som helst af de foregående krav, hvor fremgangsmåden omfatter trinnet med bestemmelse af, at der er et fremmedlegeme i de pumpede medier (18), hvis: a) den vekslende del (A:(t), A>(t), As(t)) omfatter en U-formet top med et topniveau (L4), der er tre gange større end gennemsnittet af den vekslende del (A1(t), A>(t), As(t)) uden for den U-formede top.Method according to any one of the preceding claims, wherein the method comprises the step of determining that there is a foreign body in the pumped media (18) if: a) the alternating part (A:(t), A> (t), As(t)) includes a U-shaped peak with a peak level (L4) three times greater than the average of the alternating part (A1(t), A>(t), As(t)) outside the U-shaped top. 6. Fremgangsmåde ifølge et hvilket som helst af de foregående krav, hvor fremgangsmåden omfatter trinnet med bestemmelse af, at der er grus i de pumpede medier (18), hvis variansen for den vekslende delA method according to any one of the preceding claims, wherein the method comprises the step of determining that there is gravel in the pumped media (18) if the variance for the alternating part DK 181714 B1 27 (Ai(t), A>(t), As(t)) er tre gange større end gennemsnittet af den vekslende del (A1(t), A>(t), As(t)).DK 181714 B1 27 (Ai(t), A>(t), As(t)) is three times greater than the average of the alternating part (A1(t), A>(t), As(t)). 7. Fremgangsmåde ifølge et hvilket som helst af de foregående krav, hvor > detekteringsenheden (24) omfatter et kommunikationsmodul (36), der er konfigureret til trådløs overførsel af detekterede data (28).Method according to any one of the preceding claims, wherein > the detection unit (24) comprises a communication module (36) configured for wireless transmission of detected data (28). 8. Fremgangsmåde ifølge et hvilket som helst af de foregående krav, hvor detekteringsenheden (24) omfatter et hus (40), og hvor et accelerometer (38) og en spoleanordning (60) er tilvejebragt i huset (40).Method according to any one of the preceding claims, wherein the detection unit (24) comprises a housing (40) and wherein an accelerometer (38) and a coil device (60) are provided in the housing (40). 9. Trykstødsdetekteringssystem (2) til overvågning af trykstød (10) i et miljø (20) omfattende mindst én pumpe (4) med en elektrisk induktionsmotor (8), hvor den mindst ene pumpe (4) står i fluidforbindelse med et antal rør (12, 12’) og er konfigureret til at pumpe et medium (18), hvor systemet (2) omfatter en detekteringsenhed (24), der er indrettet og konfigureret til at detektere: a) den synkrone hastighed (wg) for motorens (8) magnetfelt og Bb) motorens (8) omdrejningshastighed (om), hvor systemet (2) er konfigureret til: - i et foruddefineret tidsrum, på basis af den detekterede, synkrone hastighed (ws(t)) for motorens (8) magnetfelt og motorens (8) omdrejningshastighed (m(t)) at beregne motorens (8) sliphastighed (S(t)) som en funktion af tid (t), hvor sliphastigheden (S(t)) defineres som forskellen mellem den synkrone hastighed (ws(t)) for motorens (8) magnetfelt og motorens (8) omdrejningshastighed (øm(t)): (2) S(t) = øs(t) - w(t), kendetegnet ved, at systemet (2) er konfigureret til at: - bestemme en vekslende del (A:(t), Ax(t), As(t)) af sliphastigheden (S(); - analysere den vekslende del (Ai(t), Ax(t), As(t)) af sliphastigheden9. Pressure surge detection system (2) for monitoring pressure surges (10) in an environment (20) comprising at least one pump (4) with an electric induction motor (8), wherein the at least one pump (4) is in fluid communication with a number of pipes ( 12, 12') and is configured to pump a medium (18), the system (2) comprising a detection unit (24) arranged and configured to detect: a) the synchronous speed (wg) of the motor (8 ) magnetic field and Bb) the motor (8) rotational speed (om), where the system (2) is configured to: - for a predefined period of time, on the basis of the detected synchronous speed (ws(t)) of the motor (8) magnetic field and the motor (8) rotational speed (m(t)) to calculate the motor (8) slip speed (S(t)) as a function of time (t), where the slip speed (S(t)) is defined as the difference between the synchronous speed (ws (t)) for the magnetic field of the motor (8) and the rotational speed of the motor (8) (øm(t)): (2) S(t) = øs(t) - w(t), characterized in that the system (2) is configured to: - determine an alternating part (A:(t), Ax(t), As(t)) of the slip velocity (S(); - analyze the alternating part (Ai(t), Ax(t), As(t)) of the slip velocity DK 181714 B1 28 (S(t)) og konkludere, at trykstød (10) er til stede i ét af rørene (12, 12"), hvis: a) den vekslende del (Ai(t), A>(t), As(t)) af sliphastigheden (S(t)) omfatter tre adskilte, positive toppe (Pi, Ps, Ps), hvor tiden (ti) mellem den første positive top (P1) og den anden positive top (Ps) er længere end tiden (t) mellem den anden positive top (Ps) og den anden positive top (Ps) og b) den første positive top (Pi) er større end den anden top (P3) og den anden positive top (Pz) er større end den tredje top (Ps).DK 181714 B1 28 (S(t)) and conclude that pressure shock (10) is present in one of the pipes (12, 12"), if: a) the alternating part (Ai(t), A>(t) , As(t)) of the slip velocity (S(t)) comprises three distinct, positive peaks (Pi, Ps, Ps), where the time (ti) between the first positive peak (P1) and the second positive peak (Ps) is longer than the time (t) between the second positive peak (Ps) and the second positive peak (Ps) and b) the first positive peak (Pi) is greater than the second peak (P3) and the second positive peak (Pz) is greater than the third peak (Ps). 10. System (2) ifglge krav 9, hvor systemet er konfigureret til at bestemme middelværdien (C) af sliphastigheden (S(t)), hvor den vekslende del (Ai(t), A>(t), As(t)) af sliphastigheden (S(t)) bestemmes ved at trække middelværdien (C) af sliphastigheden (S(t)) fra sliphastigheden (S(t)).10. System (2) according to claim 9, wherein the system is configured to determine the mean value (C) of the slip velocity (S(t)) where the alternating part (Ai(t), A>(t), As(t) ) of the slip velocity (S(t)) is determined by subtracting the mean value (C) of the slip velocity (S(t)) from the slip velocity (S(t)). 11. System (2) ifølge krav 9 eller 10, hvor detekteringsenheden (24) er fastgjort til pumpens (8) motor (4), hvor detekteringsenheden (24) er konfigureret til at: a) måle magnetfeltet for en stator i motoren (8) og derved bestemme den synkrone hastighed (ws) for motorens (8) magnetfelt og b) detektere vibrationer og derved bestemme motorens (8) omdrejningshastighed (ww).11. System (2) according to claim 9 or 10, wherein the detection unit (24) is attached to the motor (4) of the pump (8), wherein the detection unit (24) is configured to: a) measure the magnetic field of a stator in the motor (8 ) thereby determining the synchronous speed (ws) of the motor (8) magnetic field and b) detecting vibrations and thereby determining the rotational speed (ww) of the motor (8). 12. System (2) ifølge krav 11, hvor motoren (4) omfatter en motoraksel (6), hvor detekteringsenheden (24) er konfigureret til, på basis af de detekterede vibrationer, at bestemme motorakslens (6) omdrejningshastighed (om).12. System (2) according to claim 11, wherein the motor (4) comprises a motor shaft (6), wherein the detection unit (24) is configured to determine, on the basis of the detected vibrations, the rotational speed (rpm) of the motor shaft (6). DK 181714 B1 29DK 181714 B1 29 13. System (2) ifølge et hvilket som helst af de foregående krav 9-12, hvor systemet (2) er konfigureret til at bestemme, at der er et fremmedlegeme i de pumpede medier (18), hvis: a) den vekslende del (A1(t), A>(t), As(t)) omfatter en U-formet top med et topniveau (Ls), der er er tre gange større end gennemsnittet af den vekslende del (A1(t), A>(t), As(t)) uden for den U-formede top.System (2) according to any one of the preceding claims 9-12, wherein the system (2) is configured to determine that there is a foreign body in the pumped media (18) if: a) the alternating part (A1(t), A>(t), As(t)) includes a U-shaped peak with a peak level (Ls) that is three times greater than the average of the alternating part (A1(t), A> (t), As(t)) outside the U-shaped peak. 14. System (2) ifølge et hvilket som helst af de foregående krav 9-13, hvor systemet (2) er konfigureret til at bestemme, at der er grus i de pumpede medier (18), hvis variansen for den vekslende del (A(t), A>(t), As(t)) er tre gange større end gennemsnittet af den vekslende del (Ai(t), A(t), As(t)).System (2) according to any one of the preceding claims 9-13, wherein the system (2) is configured to determine that there is gravel in the pumped media (18) if the variance of the alternating part (A (t), A>(t), As(t)) is three times greater than the average of the alternating part (Ai(t), A(t), As(t)). 15. System (2) ifølge et af kravene 9-14, hvor detekteringsenheden (24) omfatter et kommunikationsmodul (36), der er konfigureret til trådløs overførsel af detekterede data (28).15. System (2) according to one of claims 9-14, wherein the detection unit (24) comprises a communication module (36) configured for wireless transmission of detected data (28). 16. System (2) ifølge et af kravene 9-15, hvor detekteringsenheden (24) omfatter et hus (40), og hvor et accelerometer (38) og en spoleanordning (60) er tilvejebragt i huset (40).16. System (2) according to one of claims 9-15, wherein the detection unit (24) comprises a housing (40), and wherein an accelerometer (38) and a coil device (60) are provided in the housing (40).
DKPA202300317A 2023-04-12 2023-04-12 System and method for detecting pressure surges DK181714B1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060071666A1 (en) * 1999-09-28 2006-04-06 Reliance Electric Technologies, Llc Detection of pump cavitation/blockage and seal failure via current signature analysis
US20060127227A1 (en) * 2004-04-09 2006-06-15 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US20170248142A1 (en) * 2014-10-15 2017-08-31 Grundfos Holding A/S Method and system for detection of faults in pump assembly via handheld communication device
US20200182684A1 (en) * 2017-04-26 2020-06-11 Augury Systems Ltd. Systems and methods for monitoring of mechanical and electrical machines
EP4024147A1 (en) * 2021-01-05 2022-07-06 EWA Sensors ApS Sensor device for monitoring rotational machinery and method for monitoring rotational machinery
WO2023088931A1 (en) * 2021-11-17 2023-05-25 Grundfos Holding A/S Method and apparatus for detecting hydraulic shock

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060071666A1 (en) * 1999-09-28 2006-04-06 Reliance Electric Technologies, Llc Detection of pump cavitation/blockage and seal failure via current signature analysis
US20060127227A1 (en) * 2004-04-09 2006-06-15 A.O. Smith Corporation Controller for a motor and a method of controlling the motor
US20170248142A1 (en) * 2014-10-15 2017-08-31 Grundfos Holding A/S Method and system for detection of faults in pump assembly via handheld communication device
US20200182684A1 (en) * 2017-04-26 2020-06-11 Augury Systems Ltd. Systems and methods for monitoring of mechanical and electrical machines
EP4024147A1 (en) * 2021-01-05 2022-07-06 EWA Sensors ApS Sensor device for monitoring rotational machinery and method for monitoring rotational machinery
WO2023088931A1 (en) * 2021-11-17 2023-05-25 Grundfos Holding A/S Method and apparatus for detecting hydraulic shock

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