EP0864755B2 - Double pump with sequential or synchronous operation - Google Patents

Double pump with sequential or synchronous operation Download PDF

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Publication number
EP0864755B2
EP0864755B2 EP98104145A EP98104145A EP0864755B2 EP 0864755 B2 EP0864755 B2 EP 0864755B2 EP 98104145 A EP98104145 A EP 98104145A EP 98104145 A EP98104145 A EP 98104145A EP 0864755 B2 EP0864755 B2 EP 0864755B2
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EP
European Patent Office
Prior art keywords
pump
supply flow
pumps
switched
speed
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Legal status (The legal status 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 status listed.)
Expired - Lifetime
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EP98104145A
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German (de)
French (fr)
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EP0864755B1 (en
EP0864755A2 (en
EP0864755A3 (en
Inventor
Jürgen Resch
Jürgen Hübner
Hunnekuhl
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Wilo SE
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Wilo AG
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Publication of EP0864755A3 publication Critical patent/EP0864755A3/en
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Classifications

    • 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
    • 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
    • F04D15/02—Stopping of pumps, or operating valves, on occurrence of unwanted conditions
    • F04D15/029—Stopping of pumps, or operating valves, on occurrence of unwanted conditions for pumps operating in parallel

Definitions

  • the invention relates to a method for operating a double pump with a first pump for generating smaller flow Q kl at specifiable differential pressure between the Pumpenansaug- and the Pumpenauslouseite and a second pump switchable to the first pump for generating larger flow Q gr and one of the two pumps controlling pump control.
  • Double pumps are well known in the art and are used i.a. used in heating circuits to cover peak demand of the subsidized heating water can. Modern double pumps are controlled by changing the speed to a constant or predetermined variable end pressure.
  • Two control concepts are used for the double pumps.
  • the two pumps of the double pump are synchronized over the entire control range to cover the required flow rate, i. at the same speed, operated.
  • the second concept only one of the two pumps is initially used to cover the required flow rate. Once this pump has reached its maximum speed, the second pump is switched on and continuously upshifted to cover even larger flow rates, the first pump continues to run at maximum speed.
  • a method according to the preamble of claim 1 is known from a controller PMU 2000 in conjunction with pumps called UPE series 2000 Grundfos.
  • the object of the invention is to improve the efficiency of a conventional double pump without changing the structure of the double pump.
  • Such a controller has the advantage that the two pumps of the double pump promote almost in the entire delivery range closer to their respective optimum efficiency, so that thereby increases the overall efficiency of the double pump according to the invention.
  • Such an operation of the double pump has the further advantage that a good control accuracy can be achieved without a separate pressure sensor, only by detecting and evaluating the pump-internal parameters speed, current and absorbed power.
  • This control accuracy is ensured because the connection of the second pump falls within a range in which the power consumption increases steeply enough with increasing flow rate of the first pump, so that a change in performance is sufficiently accurately determined and thus at the achieved flow rate Q * the second pump can be switched on.
  • This is not guaranteed in known double pumps, which are operated by the second control concept, since in the range of maximum speed, the power curve is flat or falling and by monitoring the power consumption of the first pump, the connection point of the second pump can not be determined with sufficient accuracy.
  • the second pump is not switched off when the demand is not at the same flow rate Q *, in which it was previously switched on, so that an unstable operating state is avoided.
  • the so specified hysteresis prevents a permanent switching on and off of the second pump and a concomitant rapid wear of the double pump.
  • FIG. 1 shows a delivery-height flow diagram with marked pumps and load curves for the two known from the prior art control concepts.
  • FIG. 2 shows for a certain constant head, the power consumption of the two known from the prior art and explained above control concepts for double pumps. It can be clearly seen that the power required to achieve a certain flow rate Q for small flow rates in synchronous operation (first control concept) is greater than the load-dependent Zuschalt bride (second control concept), in which Reaching the maximum speed of the first pump, the second pump is connected.
  • the power curves of the two control concepts intersect with increasing flow rates at the flow rate Q *. With flow rates Q greater than Q *, the power consumption of the synchronous operation of the double pump is significantly lower than that of the connection operation when the maximum speed of the first pump is reached. Consequently, the performance curves coincide with very high flow rates when both pumps deliver at maximum speed.
  • the inventive connection of the second pump at the flow rate Q * is achieved that the power consumption P of the double pump respectively corresponds to the lowest curve above and below the flow rate Q * of the two control concepts.
  • FIG. 4 shows the power consumption of the first pump for a constant speed. It can be clearly seen that the curve shape for delivery flows Q greater than Q * flattening and even falling at even larger flow rates. If no external pressure sensor was used to determine the pressure difference between Pumpenansaug- and Pumpenauslouseite, but only the pump's internal parameters speed, power absorbed and power consumption observed so can not be determined by the up to the maximum flow flat or falling waveform of power consumption when the maximum flow rate of the pump is reached.

Description

Die Erfindung betrifft ein Verfahren zum Betrieb einer Doppelpumpe mit einer ersten Pumpe zur Erzeugung von kleineren Förderströmen Qkl bei vorgebbarem Differenzdruck zwischen der Pumpenansaug- und der Pumpenauslaßseite und einer zur ersten Pumpe zuschaltbaren zweiten Pumpe zur Erzeugung von größeren Förderströmen Qgr und einer die beiden Pumpen steuernden Pumpensteuerung.The invention relates to a method for operating a double pump with a first pump for generating smaller flow Q kl at specifiable differential pressure between the Pumpenansaug- and the Pumpenauslaßseite and a second pump switchable to the first pump for generating larger flow Q gr and one of the two pumps controlling pump control.

Doppelpumpen sind aus dem Stand der Technik hinlänglich bekannt und werden u.a. in Heizkreisläufen eingesetzt, um Bedarfsspitzen des geförderten Heizungswassers abdecken zu können. Moderne Doppelpumpen werden dabei durch Veränderung der Drehzahl auf konstanten oder vorgegebenen variablen Endruck geregelt.Double pumps are well known in the art and are used i.a. used in heating circuits to cover peak demand of the subsidized heating water can. Modern double pumps are controlled by changing the speed to a constant or predetermined variable end pressure.

Dabei kommen zwei Steuerungskonzepte für die Doppelpumpen zum Einsatz. Beim ersten Steuerungskonzept werden die beiden Pumpen der Doppelpumpe über den gesamten Regelungsbereich zur Deckung des benötigten Förderstroms synchron, d.h. mit gleicher Drehzahl, betrieben. Beim zweiten Konzept wird dagegen zuerst lediglich eine der beiden Pumpen zur Deckung des geforderten Förderstroms verwendet. Sobald diese Pumpe ihre maximale Drehzahl erreicht hat, wird die zweite Pumpe zugeschaltet und zur Deckung noch größerer Förderströme kontinuierlich hochgeregelt, wobei die erste Pumpe weiterhin mit maximaler Drehzahl läuft.Two control concepts are used for the double pumps. In the first control concept, the two pumps of the double pump are synchronized over the entire control range to cover the required flow rate, i. at the same speed, operated. In the second concept, however, only one of the two pumps is initially used to cover the required flow rate. Once this pump has reached its maximum speed, the second pump is switched on and continuously upshifted to cover even larger flow rates, the first pump continues to run at maximum speed.

Pumpen gemäß dem zweiten Steuerungskonzept sind z.B. aus den Dokumenten US 3,775,025 , GB 2 253 245 A und US 3,726,606 bekannt, wobei als Steuerungsgrößen Druck, Motorleistung bzw. benötigter Förderstrom herangezogen werden.Pumps according to the second control concept are eg from the documents US 3,775,025 . GB 2 253 245 A and US 3,726,606 known, being used as control variables pressure, engine power or required flow rate.

Ein Verfahren nach dem Oberbegriff des Anspruchs 1 ist von einer Steuerung PMU 2000 in Verbindung mit Pumpen der Bezeichnung UPE Serie 2000 der Firma Grundfos bekannt.A method according to the preamble of claim 1 is known from a controller PMU 2000 in conjunction with pumps called UPE series 2000 Grundfos.

Nachteilig wirkt sich bei diesen Steuerungskonzepten jedoch der erhöhte Energiebedarf aus. So ist der Wirkungsgrad der Pumpe bekanntlich stark abhängig vom Förderstrom.However, the disadvantage of these control concepts is the increased energy requirement. Thus, the efficiency of the pump is known to be highly dependent on the flow rate.

Aufgabe der Erfindung ist es, den Wirkungsgrad einer herkömmlichen Doppelpumpe zu verbessern ohne den Aufbau der Doppelpumpe zu verändern.The object of the invention is to improve the efficiency of a conventional double pump without changing the structure of the double pump.

Dies Aufgabe wird erfindungsgemäß durch die Merkmale des Anspruchs 1 gelöst.This object is achieved by the features of claim 1.

Eine derartige Steuerung hat den Vorteil, daß die beiden Pumpen der Doppelpumpe fast im gesamten Förderbereich näher an ihrem jeweiligen Wirkungsgradoptimum fördern, so daß sich hierdurch der Gesamtwirkungsgrad der erfindungsgemäßen Doppelpumpe erhöht.Such a controller has the advantage that the two pumps of the double pump promote almost in the entire delivery range closer to their respective optimum efficiency, so that thereby increases the overall efficiency of the double pump according to the invention.

Ein derartiger Betrieb der Doppelpumpe hat weiterhin den Vorteil, daß ohne einen separaten Drucksensor, nur durch Erfassung und Auswertung der pumpeninternen Parameter Drehzahl, Strom und aufgenommene Leistung, eine gute Regelgenauigkeit erreicht werden kann. Diese Regelgenauigkeit ist deshalb gewährleistet, da das Zuschalten der zweiten Pumpe in einem Bereich fällt, in dem die Leistungsaufnahme bei zunehmendem Förderstrom der ersten Pumpe noch steil genug ansteigt, so daß eine Leistungsänderung genügend genau ermittelbar ist und somit bei erreichtem Förderstrom Q* die zweite Pumpe zugeschaltet werden kann. Dies ist bei bekannten Doppelpumpen, welche mittels des zweiten Steuerungskonzepts betrieben werden nicht gewährleistet, da im Bereich der maximalen Drehzahl die Leistungskurve flach bzw. fallend verläuft und durch die Beobachtung der Leistungsaufnahme der ersten Pumpe der Zuschaltpunkt der zweiten Pumpe nicht hinreichend genau ermittelbar ist.Such an operation of the double pump has the further advantage that a good control accuracy can be achieved without a separate pressure sensor, only by detecting and evaluating the pump-internal parameters speed, current and absorbed power. This control accuracy is ensured because the connection of the second pump falls within a range in which the power consumption increases steeply enough with increasing flow rate of the first pump, so that a change in performance is sufficiently accurately determined and thus at the achieved flow rate Q * the second pump can be switched on. This is not guaranteed in known double pumps, which are operated by the second control concept, since in the range of maximum speed, the power curve is flat or falling and by monitoring the power consumption of the first pump, the connection point of the second pump can not be determined with sufficient accuracy.

Es ist weiterhin vorteilhaft, wenn die zweite Pumpe bei sinkendem Bedarf nicht bei dem gleichen Förderstrom Q* abgeschaltet wird, bei dem sie vorher zugeschaltet wurde, damit ein instabiler Betriebszustand vermieden wird. Die so vorgegebene Hysterese verhindert ein dauerndes Zu- und Abschalten der zweiten Pumpe und einen damit einhergehenden schnellen Verschleiß der Doppelpumpe.It is also advantageous if the second pump is not switched off when the demand is not at the same flow rate Q *, in which it was previously switched on, so that an unstable operating state is avoided. The so specified hysteresis prevents a permanent switching on and off of the second pump and a concomitant rapid wear of the double pump.

Nachfolgend wird anhand von Diagrammen die Erfindung näher erläutert.The invention will be explained in more detail with reference to diagrams.

Es zeigen:

Figur 1
Ein Förderhöhe-Förderstrom-Diagramm für eine Doppelpumpe;
Figur 2
ein Leistungsaufnahme-Diagramm für eine Doppelpumpe im Synchron- sowie im lastabhängigen Zuschaltbetrieb;
Figur 3
ein Förderhöhe-Förderstrom-Diagramm für die erfindungsgemäße Doppelpumpe;
Figur 4
ein Leistungsaufnahme-Förderstrom-Diagramm für eine Pumpe der Doppelpumpe.
Show it:
FIG. 1
A head-flow diagram for a double pump;
FIG. 2
a power consumption diagram for a double pump in synchronous and load-dependent connection operation;
FIG. 3
a head-flow diagram for the double pump according to the invention;
FIG. 4
a power consumption flow diagram for a pump of the double pump.

Figur 1 zeigt ein Förderhöhe-Förderstrom-Diagramm mit eingezeichneten Pumpen und Verbraucherkennlinien für die beiden aus dem Stand der Technik bekannten Steuerungskonzepte. FIG. 1 shows a delivery-height flow diagram with marked pumps and load curves for the two known from the prior art control concepts.

Figur 2 zeigt für eine bestimmte konstante Förderhöhe die Leistungsaufnahme der beiden aus dem Stand der Technik bekannten und oben erläuterten Steuerungskonzepten für Doppelpumpen. Es ist deutlich zu erkennen, daß die benötigte Leistung zur Erzielung eines bestimmten Förderstroms Q bei kleinen Förderströmen im Synchronbetrieb (erstes Steuerungskonzept) größer ist als beim lastabhängigen Zuschaltbetrieb (zweites Steuerungskonzept), bei dem nach Erreichen der maximalen Drehzahl der ersten Pumpe die zweite Pumpe hinzugeschaltet wird. Die Leistungskurven der beiden Steuerungskonzepte schneiden sich bei größer werdenden Förderströmen beim Förderstrom Q*. Bei Förderströmen Q größer Q* ist die Leistungsaufnahme des Synchronbetriebs der Doppelpumpe deutlich geringer als die des Zuschaltbetriebes bei Erreichen der maximalen Drehzahl der ersten Pumpe. Die Leistungskurven decken sich konsequenterweise bei sehr großen Förderströmen, wenn beide Pumpen mit maximaler Drehzahl fördern. FIG. 2 shows for a certain constant head, the power consumption of the two known from the prior art and explained above control concepts for double pumps. It can be clearly seen that the power required to achieve a certain flow rate Q for small flow rates in synchronous operation (first control concept) is greater than the load-dependent Zuschaltbetrieb (second control concept), in which Reaching the maximum speed of the first pump, the second pump is connected. The power curves of the two control concepts intersect with increasing flow rates at the flow rate Q *. With flow rates Q greater than Q *, the power consumption of the synchronous operation of the double pump is significantly lower than that of the connection operation when the maximum speed of the first pump is reached. Consequently, the performance curves coincide with very high flow rates when both pumps deliver at maximum speed.

Aus dem Leistungsdiagramm der Figur 2 ist ferner zu entnehmen, daß die Leistungsaufnahme beim Zuschalten der zweiten Pumpe (zweites Steuerungskonzept) sprunghaft steigt.From the performance diagram of FIG. 2 can also be seen that the power consumption increases when connecting the second pump (second control concept) leaps and bounds.

Durch das erfindungsgemäße Zuschalten der zweiten Pumpe bei dem Förderstrom Q* wird erreicht, daß die Leistungsaufnahme P der Doppelpumpe jeweils dem niedrigsten Kurvenverlauf ober- und unterhalb des Förderstroms Q* der beiden Steuerungskonzepte entspricht.The inventive connection of the second pump at the flow rate Q * is achieved that the power consumption P of the double pump respectively corresponds to the lowest curve above and below the flow rate Q * of the two control concepts.

Zur Erzielung des stabilen Betriebszustands erfolgt, wie aus Figur 3 ersichtlich ist, das Zuschalten der zweiten Pumpe nicht beim gleichen Förderstrom wie das Abschalten. Dabei muß der Förderstrom Qzu zur Erzeugung einer Hysterese größer als der Abschaltförderstrom Qab gewählt werden.To achieve the stable operating state takes place as out FIG. 3 it can be seen, the connection of the second pump not at the same flow as the shutdown. In this case, the flow Q must be selected to generate a hysteresis greater than the Abschaltförderstrom Q from .

Figur 4 zeigt die Leistungsaufnahme der ersten Pumpe für eine konstante Drehzahl. Es ist deutlich zu erkennen, daß sich der Kurvenverlauf für Förderströme Q größer Q* abflacht und bei noch größeren Förderströmen sogar fallend ist. Würde kein externer Drucksensor zur Ermittlung der Druckdifferenz zwischen Pumpenansaug- und Pumpenauslaßseite verwendet, sondern würden ausschließlich die pumpeninternen Parameter Drehzahl, aufgenommene Leistung sowie Stromaufnahme beobachtet, so kann durch den bis zum maximalen Förderstrom flach bzw. abfallenden Kurvenverlauf der Leistungsaufnahme nicht sicher festgestellt werden, wann der maximale Förderstrom der Pumpe erreicht ist. FIG. 4 shows the power consumption of the first pump for a constant speed. It can be clearly seen that the curve shape for delivery flows Q greater than Q * flattening and even falling at even larger flow rates. If no external pressure sensor was used to determine the pressure difference between Pumpenansaug- and Pumpenauslaßseite, but only the pump's internal parameters speed, power absorbed and power consumption observed so can not be determined by the up to the maximum flow flat or falling waveform of power consumption when the maximum flow rate of the pump is reached.

Durch das erfindungsgemäße Zuschalten der Pumpe bei dem Förderstrom Q*, welcher deutlich kleiner ist als der Förderstrom Q bei maximaler Drehzahl der ersten Pumpe, wird erreicht, daß das Zuschalten der zweiten Pumpe in einen Bereich der Leistungsaufnahme-Kurve gem. Figur 4 fällt, bei dem der Kurvenverlauf noch genügend steil ansteigend ist, so daß mit der Beobachtung der pumpeninternen Parameter der Zuschaltpunkt hinreichend genau bestimmbar ist.The inventive connection of the pump at the flow rate Q *, which is significantly smaller than the flow rate Q at maximum speed of the first pump, it is achieved that the connection of the second pump in a range of power consumption curve gem. FIG. 4 falls, in which the curve is still sufficiently steeply rising, so that with the observation of the pump-internal parameters of the Zuschaltpunkt is sufficiently accurately determined.

Die Ermittlung des Differenzdrucks bzw. des momentan geförderten Förderstroms Q einer Pumpe mit Hilfe der pumpeninternen Parameter ist Stand der Technik und soll hier nicht weiter erläutert werden.The determination of the differential pressure or the currently funded flow rate Q of a pump with the aid of the pump-internal parameters is state of the art and will not be explained further here.

Claims (5)

  1. Procedure for operating a double pump with a first pump to produce smaller supply flows Qkl at a specifiable differential pressure between the pump intake side and the pump output side and a second pump which can be switched on to work together with the first pump to produce larger supply flows Qgr, and a pump control controlling the two pumps, wherein the pump control continually increases the speed of the first pump until a specified supply flow Q* is reached, in which the second pump is switched off until the specified supply flow Q* is reached, and when the supply flow Q* is reached, the pump control switches on the second pump to work together with the first pump and both pumps feed at the same speed for all supply flows Q >= Q* (Q is greater than or equal to Q*), characterised in that, when switching on, the pump control decreases the speed of the first pump to the speed of the second pump in such a manner that the supply flow Qzu that is produced solely by the first pump prior to switching on the second pump, is produced in identical parts conjointly by both pumps after switching on.
  2. Procedure in accordance with claim 1, characterised in that, starting from a supply flow of Q > Q* (Q is greater than Q*), the pump control switches off the second pump in the event of falling demand as soon as the supply flow Q produced by both pumps is approximately equal to Q*.
  3. Procedure in accordance with claim 1 or 2, characterised in that the second pump is switched on at a supply flow Qzu and switched off at a supply flow Qab, in which Qzu > Qab.
  4. Procedure in accordance with one of the preceding claims, characterised in that, when the second pump is switched off, the pump control increases the speed of the first pump in such a manner that the supply flow produced by the first pump is identical to the supply flow produced conjointly by both pumps prior to the second pump being switched off.
  5. Procedure in accordance with one of the preceding claims, characterised in that the supply flow Q produced by the double pump can be determined by means of the pumps' internal parameters of speed, electricity input and power consumed.
EP98104145A 1997-03-14 1998-03-09 Double pump with sequential or synchronous operation Expired - Lifetime EP0864755B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19710675 1997-03-14
DE19710675A DE19710675B8 (en) 1997-03-14 1997-03-14 Double pump with single and synchronous operation

Publications (4)

Publication Number Publication Date
EP0864755A2 EP0864755A2 (en) 1998-09-16
EP0864755A3 EP0864755A3 (en) 2000-11-29
EP0864755B1 EP0864755B1 (en) 2003-08-13
EP0864755B2 true EP0864755B2 (en) 2011-03-16

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DE (2) DE19710675B8 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014222962A1 (en) 2014-11-11 2016-05-12 Ksb Aktiengesellschaft Efficient operation of multi-pump systems
DE102017223189A1 (en) 2017-12-19 2019-06-19 KSB SE & Co. KGaA Multi-pump system and method for its operation

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Publication number Priority date Publication date Assignee Title
DE19958829C1 (en) 1999-11-30 2001-08-02 Mannesmann Ag Fuel cell system with a device for supplying fuel
EP1984628B1 (en) * 2006-02-13 2014-12-17 Ingersoll-Rand Company Multi-stage compression system and method of operating the same
DE102010055841A1 (en) 2010-12-23 2012-06-28 Wilo Se Method for operating a double pump or multi-pump unit
WO2018137019A1 (en) 2017-01-27 2018-08-02 S. A. Armstrong Limited Dual body variable duty performance optimizing pump unit
CA172776S (en) 2017-01-27 2017-10-23 S A Armstrong Ltd Control pump
EP3421805A1 (en) * 2017-06-30 2019-01-02 Taco, Inc. Self-sensing parallel control of pumps

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Publication number Priority date Publication date Assignee Title
DE3225141A1 (en) † 1982-07-06 1984-02-16 Grundfos A/S, 8850 Bjerringbro SPEED-CONTROLLED PUMP UNIT
DE4128390C1 (en) † 1991-08-27 1992-12-24 Loewe Pumpenfabrik Gmbh, 2120 Lueneburg, De Rapid control appts. for fluid supply installation - has controller connected via digital communication line to pump motor regulators which provide setting signals for frequency converters

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US3726606A (en) * 1971-11-19 1973-04-10 A Peters Sump apparatus
US3970413A (en) * 1972-01-24 1976-07-20 Francois Duveau Fluid distribution apparatus and method
US3775025A (en) * 1972-02-02 1973-11-27 Maher Corp Constant pressure pumping unit
DE3238020A1 (en) * 1982-10-13 1984-04-19 Linde Ag, 6200 Wiesbaden Device for conveying a liquid
DE3918246A1 (en) * 1989-06-05 1990-12-06 Eggs Elektrotechnik Water pressure intensifier system - incorporates single pump with adjustable capacity
GB2253245B (en) * 1991-02-28 1994-10-19 Hamworthy Heating Ltd Flow related control means for a pump

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3225141A1 (en) † 1982-07-06 1984-02-16 Grundfos A/S, 8850 Bjerringbro SPEED-CONTROLLED PUMP UNIT
DE4128390C1 (en) † 1991-08-27 1992-12-24 Loewe Pumpenfabrik Gmbh, 2120 Lueneburg, De Rapid control appts. for fluid supply installation - has controller connected via digital communication line to pump motor regulators which provide setting signals for frequency converters

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014222962A1 (en) 2014-11-11 2016-05-12 Ksb Aktiengesellschaft Efficient operation of multi-pump systems
DE102017223189A1 (en) 2017-12-19 2019-06-19 KSB SE & Co. KGaA Multi-pump system and method for its operation
WO2019121753A1 (en) 2017-12-19 2019-06-27 KSB SE & Co. KGaA Multiple pump system and method for the operation thereof

Also Published As

Publication number Publication date
DE19710675B8 (en) 2012-03-29
EP0864755B1 (en) 2003-08-13
EP0864755A2 (en) 1998-09-16
EP0864755A3 (en) 2000-11-29
DE19710675B4 (en) 2012-01-12
DE59809242D1 (en) 2003-10-02
DE19710675A1 (en) 1998-09-17

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