EP2354555B2 - Method for optimising the energy of pumps - Google Patents

Description

The invention relates to a method for energy optimization in the operation of several speed-controllable centrifugal pumps in a hydraulic system.

In particular, in heating systems of larger buildings or more complex design is a variety of pumps, ie centrifugal pumps installed with this driving electric motor to reliably provide the individual parts of the system with fluid or heat. Modern pumps of this type are speed controllable, ie they have a frequency converter or speed controller and appropriate control electronics, with which they can supply a wide range of hydraulic requirements in terms of performance. When a plurality of such pumps work together in a plant, be it by parallel, series or combination thereof, results in a complex hydraulic network, which often makes it difficult to see which pump which function. It is even more difficult, of course, to operate these pumps in such a way that, in total, they run only approximately energy-optimized. See for example DE 10 2004 041 661 A1 ,

Against this background, the invention has the object to provide a method for energy optimization of the pumps of such a hydraulic system, without the performance of the system, in particular the supply of all system components suffers.

This object is achieved according to the invention by the method specified in claim 1. The invention further provides a pump for carrying out this method according to claim 12. Advantageous embodiments of the invention are set forth in the subclaims, the following description and the drawing.

The inventive method for energy optimization in the operation of several speed-controllable centrifugal pumps in a hydraulic system, eg. As a heating system, a Grundwasserabsenkungsanlage, an irrigation system, a sewage plant and the like based on that is first determined which pumps are assigned as pilot pumps directly to a consumer and which pumps are arranged downstream of the pilot pumps, after which the downstream pump for energy optimization with varying speeds be controlled.

The basic idea of the method according to the invention is therefore to first of all determine which pumps of the system are pilot pumps. Pilot pumps are those pumps that are directly associated with a consumer, d. H. Pumps whose input or output is typically assigned directly to a consumer. In the majority of cases such pumps are typically located in front of the consumer, but they may also be behind the consumer, d. H. These are then pilot pumps which connect to the consumer on the suction side. So, pilot pumps are all the pumps that connect directly to a consumer, whether on the suction side or on the pressure side. These pilot pumps are the pumps that primarily supply the consumer and are therefore only indirectly used for energy optimization. For this purpose, according to the invention, the pumps arranged downstream of the pilot pumps are provided, which are controlled at varying speeds in order to achieve energy optimization. These downstream pumps are thus varied in their speeds until an energy optimization is achieved. Thus, as described below, an energy optimization of the pilot pumps is achieved, which change their operating point as typically controlled pumps.

Energy optimization in the sense of the invention does not necessarily have to be a best state, but can also consist in an improvement in the energy efficiency of the plant compared to an actual state.

The pilot pumps downstream pumps in the context of the invention are in the pilot pumps that promote directly into a consumer, these hydraulically upstream pumps. In the case of the pilot pumps which discharge from a consumer, ie which are connected to the consumer on the suction side, the downstream pumps are the pumps which are hydraulically connected downstream.

According to the invention, one or more energy optimization circuits are formed, each consisting of one or more pilot pumps and one or more downstream pumps, which are pumped into or supplied from the pilot pumps, with downstream pumps each associated with only one energy optimizing circuit, after which the one or more Energy optimization circuits are energy-optimized.

The basic idea here is therefore first of all to divide up the possibly complex hydraulic system into energy optimization circuits, which are selected such that simplified system parts are formed which can be energy-optimized without great effort.

An energy optimization circuit is always formed from one or more pilot pumps and one or more downstream pumps, which feed into the pilot pump or are fed from these. The downstream pumps need not be direct, but may also indirectly feed into or feed from the pilot pumps, depending on how far they are hydraulically subordinate.

The energy optimization circuits are chosen so that downstream pumps are each assigned to only one energy optimization circuit. In contrast, one or more pilot pumps can also be assigned to several energy optimization circuits.

The basic idea is to form energy optimization circuits in which there is at least one pilot pump at the end or beginning, wherein the pilot pump, which is immediately before or behind the consumer, for the hydraulic supply to the consumer, in particular the required delivery height has to ensure, whereas the upstream or hydraulically downstream pumps can be changed in their control until the total energy consumption of the energy optimization circuit has a minimum or at least is reduced. If all of the energy optimization circuits so formed are energy-optimized, then the entire hydraulic system is also energy-optimized with regard to the operation of the centrifugal pumps incorporated therein. The energy optimization circuits are optimized one after the other, irrespective of the order in which the circuits are optimized. The optimization process is expediently carried out continuously during the operation of the pumps so that the energy optimization takes place again in the case of hydraulic changes in the system on the basis of the changed operating points of the pump.

An energy optimization circuit typically has one or more pilot pumps, as well as one or more downstream pumps, wherein the downstream pumps directly convey into at least one pilot pump or are directly fed from at least one pilot pump.

According to an advantageous development of the method according to the invention, an energy optimization circuit comprises all the pilot pumps into which the one or more downstream pumps deliver or from which the downstream pumps are fed.

In order to optimize an energy optimization circuit, a size e is determined according to the invention for each pump, which quantity is determined by the quotient of the change in the absorbed power and the change in the hydraulic output of the pump. The sizes e of the pilot pumps are then optionally d. H. if there are several, add and match the magnitude e of each of these upstream and downstream pumps by variance of the drive of these pumps, with parallel connected upstream or downstream pumps being considered as a pump. The basic idea is to take into account the change in power consumption, typically the electrical line intake of the pump with the change in the hydraulic power output and add these quotients of the pilot pump and then to vary the control of the downstream pumps until they add to this by addition the individual quotient of the size of the pilot pump formed e coincides, since then the power absorbed by the energy optimization circuit power is minimal or at least low. The size e of each downstream pump is to be equated with the size which is formed by the addition of the corresponding quotients of the pilot pumps. In this case, the energy optimization takes place such that a size e of one or more pilot pumps is determined at the time t = 0 and subsequently energy-optimized on the basis of this variable e, the downstream pumps as described above. It is understood that if the downstream pumps are energy-optimized based on the quantity e at time t = 0, this size e of the one or more pilot pumps changes, so that at the end of the optimization process of the energy optimization circuit at time t = 1 a variable e possibly deviating from the size e at the time t = 0 at time t = 1. The optimization process can then be performed again by determining the size e of the one or more pilot pumps at time t = 1 and driving the downstream pumps accordingly. The more frequently this process is carried out, the better the result, with almost no change in the system soon reaching an almost optimal value. In order to arrive as quickly as possible at the desired optimization result, it is particularly expedient not to compensate the difference in the E values between the sum of the pilot pumps and the pump to be optimized in one speed step, but only a part thereof, preferably between 20% and 50%. , This already takes into account the change in the E values of the pilot pumps. This percentage is system-specific and depends on the dynamic behavior of consumers. Thus, the energy optimization circuits are expediently energy-optimized in succession and constantly in the manner described above in order to operate the plant in a conservative manner even in the event of changing operating conditions.

If pumps are connected in parallel within this energy optimization circuit, then these are considered as a common pump, that is to say with a common variable e, with an optimization method which is described below being advantageously used for the pumps connected in parallel.

The power consumed is expediently taken from the electrical power P of the drive motor, which is available on a pump-side basis in the case of rotary-number-controlled pumps on a regular basis without appreciable expense.

Since the hydraulic output of a pump is difficult to determine, is provided according to a development of the invention, as a measure of the delivered hydraulic power, the head h of the pump or the flow q of the pump to use. As will be described below, depending on the hydraulic task, the delivery head h or the delivery rate q is used to form the variable e. These variables are advantageously provided by the pump itself, since a corresponding signal in speed-controlled pumps, which typically have a control electronics, without major Effort can be provided. It is expedient to provide in parallel both a signal representing the quotient of the change in the recording of the electrical power P and the change in the delivery height h, as well as an electrical signal which is the quotient of the change in the absorbed power P and the change represents the flow q. Both signals can be used depending on the choice of optimizing circuit in the inventive method. The variables themselves typically need not be determined separately on the pump side, since, for example, in modern frequency converter-controlled pumps for the entire characteristic diagram of the operating points, the electrical and hydraulic properties of the pump are known and stored in an electronic memory. As a rule, they can therefore always be calculated by linking the stored values. Instead of using the change in the hydraulic output power of the pump, a quantity directly related thereto, for example in a heating system, the change in the amount of heat Q, which is a function of the flow rate q and the temperature difference .DELTA.T (Q = q * .DELTA.T) or another related change in size is used. In order to optimize energy in parallel with one another as described above in the method according to the invention within an energy optimization circuit, according to a further development of the invention, these pumps are controlled such that the size eq of the parallel-connected pumps is the same is large, wherein the size eq is formed by the quotient of the change in absorbed power P and the change in the delivery rate q of the respective pump. It is therefore used in parallel-connected pumps as a characteristic variable for the output hydraulic power, the flow rate, which makes sense, since parallel-connected pumps are designed to realize a Födermenge that could not be provided with a single pump or at least not economically.

In heating systems, in which parallel-connected pumps are operated as so-called double pumps, it may be provided not to provide such a double pump for the parallel operation of two pumps, but only as a replacement pump in case of failure of the other pump. Then it goes without saying that due to a signal provided by this double pump, the shut-down pump is not involved in energy optimization.

If parallel-connected pumps have been energy-optimized as described above, then in the method according to the invention they are to be regarded as a single pump. Since for the energy optimization of such pumps not connected in parallel, the delivery height h, ie, the booster pressure, is used as the quantity for the hydraulic power, in the case of the pump according to the invention the size e _h is formed in that the quotient of the change in absorbed power P and the change in the delivery height h of each of the parallel-connected pumps is determined and these quotients are then added.

In the case of pumps connected in series, whether these are individual pumps connected in series or groups of pumps connected in parallel, or both, an amount e _h , which is determined by the quotient of the change in absorbed power P and the change in the delivery head, is advantageously used for energy optimization h the respective pump or pump group (as described above) is formed. This quantity e _h is then equated to the corresponding size eh, possibly formed by addition, of the associated pilot pumps, variable sizes being achieved by variance of the control of the downstream pumps on both sides, and thus energy optimization being achieved.

The energy optimization method according to the invention has its limits where a pump reaches saturation, ie. H. promotes on the curve of their maximum performance. Then, this pump can not be controlled to increase performance, which is to be considered in the energy optimization process, be it that a pilot pump is approaching the saturation limit to be supported hydraulically by downstream pumps or a downstream pump that comes close to the saturation limit, in as far as not allowed to absorb higher power in the course of the energy optimization process.

The energy optimization method according to the invention fundamentally requires the knowledge of the functional relationship of the hydraulic system. According to one embodiment of the invention, however, the functional relationship of the hydraulic system can also be determined by appropriate control of the pump in the system by the pump itself. It is provided according to the invention that of the pumps in the system at least one pump is initially controlled with a first and then compared to the first speed speed, the resulting hydraulic variables or changes are detected on the consumer side and / or pump side and conclusions about the hydraulic arrangement can be made on the basis of these values. For example, by two pumps by speed control of one of the pumps and pressure measurement or flow measurement can be easily determined whether the pumps are connected in parallel or in series. According to this principle, finally, the functional hydraulic relationship of the entire system can be determined, as illustrated below with reference to an embodiment.

According to the invention, the functional relationship of several controllable in their speed Pumps in a system determined by the fact that in at least one pump, the speed is changed and determined from the resulting hydraulic reaction at least a functional relationship of the system. Depending on the extent of the functional relationship to be determined, one or more pumps with a different speed can be controlled in order to determine this relationship. Thus, for example, to determine whether two pumps are connected in parallel or in series are sufficient to control one of the pumps at an increased speed to then determine by pressure or flow measurement compared to the original state in which way these pumps are connected.

1. a) In einem ersten Verfahrensschritt werden alle in der Anlage verbauten Pumpen mit vorzugsweise konstanter Drehzahl angesteuert und zu jeder Pumpe oder zu jedem den Pumpen zugeordneten Verbraucher oder jeder Verbrauchergruppe, wenn einer Pumpe mehrere Verbraucher zugeordnet sind, eine hydraulische Größe erfasst. Typischerweise werden die Pumpen dabei mit einer konstanten mittleren Drehzahl angesteuert und zwar solange, bis sich quasi stationäre Werte einstellen. Diese Werte werden entweder pumpenweise oder verbraucherweise erfasst, es handelt sich dabei wahlweise um den Druck oder den Volumenstrom (Fördermenge), wobei diese nicht notwendigerweise direkt erfasst werden müssen, sondern in an sich bekannter Weise auch durch andere Größen, z.B. elektrische Größen des Antriebs der Pumpen indirekt ermittelt werden können.
2. b) Es werden dann nacheinander jeweils eine der Pumpen oder mehrere Pumpen mit veränderter Drehzahl angesteuert und die sich dabei jeweils ergebende Änderung der hydraulischen Grö-βen erfasst. Es wird also jede einzelne Pumpe typischerweise mit einer gegenüber der gemäß Schritt a erhöhten Drehzahl angesteuert und es werden dann die Änderungen der hydraulischen Größen erfasst, die sich entweder verbraucherseitig oder pumpenseitig ergeben, wobei pumpenseitig sowohl die hydraulischen Größen der mit veränderter Drehzahl angesteuerten Pumpe als auch die der anderen Pumpen erfasst werden. Grundsätzlich spielt es dabei keine Rolle, ob die veränderte Drehzahl eine gegenüber der Drehzahl gemäß Schritt a erhöhte oder erniedrigte ist, vorteilhaft wird jedoch in der Regel eine demgegenüber erhöhte Drehzahl gewählt. Es versteht sich, dass in gleicher Weise nacheinender alle Pumpen entweder mit gegenüber der Drehzahl im Schritt a erhöhter oder aber abgesenkter Drehzahl betrieben werden müssen um die sich dabei ergebenden hydraulischen Änderungen der hydraulischen Größen zu erfassen.
3. c) In einem dritten Verfahrensschritt wird dann nachdem die Änderungen der hydraulischen Größen erfasst sind die Zuordnung der Pumpen oder Pumpengruppe zu den Verbrauchern oder Verbrauchergruppen anhand dieser erfassten hydraulischen Größenänderungen bestimmt.

According to an advantageous development of the invention, the method is applied in three basic method steps, namely as follows:

1. a) In a first process step, all installed in the system pumps are driven with preferably constant speed and to each pump or to each pump associated consumers or each consumer group, when a pump is assigned to several consumers, detects a hydraulic variable. Typically, the pumps are driven at a constant average speed and that until quasi-stationary values set. These values are either pump-wise or consumer-detected, it is either the pressure or the flow rate (flow), which need not necessarily be detected directly, but in a conventional manner by other sizes, such as electrical variables of the drive Pumps can be determined indirectly.
2. b) One of the pumps or a plurality of pumps with a different speed is then activated one after the other in each case and the change in the hydraulic quantities resulting therefrom is detected in each case. Thus, each individual pump is typically controlled with respect to the speed increased according to step a and then the changes of the hydraulic variables are detected, resulting either on the consumer side or on the pump side, wherein pump both the hydraulic variables of the pump controlled at a different speed and that of the other pumps are detected. In principle, it does not matter whether the changed speed is increased or decreased in comparison with the speed of step a, but as a rule an increased speed is advantageously selected. It is understood that in the same way nacheinender all pumps must be operated either with respect to the speed in step a increased or lowered speed to capture the resulting hydraulic changes in the hydraulic variables.
3. c) In a third method step, after the changes in the hydraulic variables are detected, the assignment of the pumps or pump group to the consumers or consumer groups is determined on the basis of these detected hydraulic changes in size.

The method according to the invention can be implemented in the digital frequency converter electronics in the case of the advantageous use of frequency converter-controlled pumps, in which case a data connection between the pumps should be formed wirelessly or wirelessly, for example via network cables, in order to appropriately coordinate the pumps in accordance with the method and furthermore the hydraulic variables to detect at the pumps or at the consumers. However, this method can also be implemented in a separate controller, which is connected in a wired or wireless manner to the pumps and possibly to the consumers or their sensors.

The method according to the invention offers the great advantage that it can be carried out with equipment that is typically present anyway in the heating system, ie. H. with the exception of the controller and the data network, no additional measures should be provided in the system. However, control and data combination can be integrated with a suitable design of the pump in this at only a small additional cost. In addition, the data network is not required for the subsequent energy optimization process.

The evaluation of the thus determined hydraulic variables and size changes can be done in a simple manner. In this case, the methods fundamentally differ as to whether the hydraulic variables or their changes are detected on the pump side or the consumer side.

If the sizes on the consumer side, d. H. in a consumer or a consumer group, when multiple consumers are associated with a pump, then, according to a development of the method in the pumps that produce the same consumer-side hydraulic size changes when driving at a different speed determined that they are assigned to a pump group. A pump group consists of two or more pumps connected in parallel and / or in series. The first assignment step is therefore to determine on consumer-side size detection, whether the pumps are hydraulically interconnected as individual pumps or in groups in the system.

According to a further advantageous embodiment of the method, it is found that when at a speed change of one or sequentially following several pumps only one consumer or a consumer group is influenced according to the speed change increasing or decreasing, that then the pump or pumps are assigned to each affected consumer or each affected consumer group directly, ie no more pumps more in the conduction path between the aforementioned pump / the aforementioned pump and the Consumer or consumer group.

In order to determine the functional relationship within a pump group is provided according to a development of the method to control all pumps of the pump group with constant speed, so for example according to step a, in which case the pressure difference generated by the respective pump, for example by a differential pressure sensor to the respective pump is detected. It is then successively each one of the pumps controlled with a modified, preferably increased pressure and detects the resulting differential pressure change or speed changes of the other pumps, after which the assignment of the pump within the pump group is determined based on the detected size changes, as this is based on the hydraulic Basic laws for parallel or Reiheschaltung of pumps results. In order to determine the functional relationship within the pump group, either the pumps of a pump group can subsequently be actuated with a changed, preferably increased speed and the flow rate can be detected by the respective pump or else the pumps are actuated one after the other to generate an increased differential pressure, in which case the pressure levels that are established recorded this and the other pumps and the assignment of the pump is determined within the pump group based on the possibly resulting changes.

According to an advantageous development of the method according to the invention, the pump or the pumps, which in their speed change two or more consumers or consumer groups according to the speed change increasing or decreasing influence according to the number of affected consumers or consumer groups assigned. It can thus be determined which pumps apply which load and thus the assignment of the pumps are determined among each other.

It is particularly advantageous if in the method according to the invention it is not the absolute values of the hydraulic variables or size changes that are detected, but only their direction, since then a very simple and non-calibrated sensor system can be used on the one hand and only low computing power on the other hand and reduced space requirements needed. It is therefore sufficient for carrying out the method according to the invention to detect whether the respectively detected hydraulic variable increases or decreases at speed or pressure change of a specific pump. It only depends on a simplified direction detection, which is sufficiently accurate if it can be categorized into three groups, namely greater (+1), smaller (-1) and equal (0).

If the inventive method to be performed by detecting the hydraulic variables of the pump, so for example, the pressure or the flow rate, which is generally cheaper in terms of equipment, since frequenzumrichtergesteuerte heating circulation pumps are now regularly equipped with differential pressure sensors, then it is expedient, first with the Method to determine whether the hydraulic system is a hydraulic network or whether it consists of two or more independent parts of the system. In independent parts of the system has a speed change or pressure increased control of a pump in the other part of any influence, so that in this way with the method initially the hydraulically miteinender connected equipment parts can be determined.

The methods in which, for determining the functional relationship, hydraulic variables of the pumps, typically pressure or differential pressure or volumetric flow, are in principle different from one another.

If what is provided according to an embodiment of the invention, the volume flows and thus hydraulic changes in volume flow changes are detected, then the functional relationship of the pumps can be determined as follows, wherein the changes in driving a pump with increasing speed noted below are. It should be stressed, however, that the

Changes can be used in an analogous manner, if the control is carried out at reduced speed:
A matrix is formed in which the hydraulic changes of at least one hydraulically independent part of the plant are detected, whereby the directional changes are advantageously also detected here, ie the matrix is formed with the values 0 for steady, +1 for rising and -1 for falling , In this case, line by line to each pump which results in their control at a different speed changes in the hydraulic variables at this pump and at the other pumps. Furthermore, each column is assigned a column, with the rows within the matrix sorted according to their number of ascending changes (+1) ascending from top to bottom and the columns corresponding to their number of ascending changes (+1) ascending from left to right , In the top line of the matrix, therefore, the changes of the pump are recorded, which have the fewest changes in generates the totality of the pump, the associated column of this pump joins at the same place in the upper left of the matrix. The pump with the most increasing changes is in the last, so lowest line, which pump is then also the last column, so assigned the rightmost column. It is understood that the matrix, since it is necessarily mirror-symmetrical with respect to its diagonal, can also be arranged in exactly the opposite way.

The matrix is divided by a diagonal, which runs from one to the other matrix axis which quasi cuts or erases the fields of the matrix, in which an increasing size change is typically a 1. These are the fields where the pump assignment of column and row match. By considering the number of increasing changes in the hydraulic variables in each column below the aforementioned diagonals or in each row above the aforementioned diagonal, it can then be determined which pumps are hydraulically connected next to each other and which hydraulically in series.

For the pumps where an equal number of incremental changes (+1) of the hydraulic variables are indicated in the columns below the diagonal or in the lines above the diagonal of the matrix, these are pumps connected side by side, ie those pumps which are off same line and out of the same pressure level.

According to a development of the method according to the invention, the pumps are determined, which are assigned directly to a consumer or to a consumer group, d. H. promote in such a consumer or a consumer group without the interposition of other pumps. These are the pumps where there is no increasing change in hydraulic sizes in a row below the diagonal or in a column above the diagonal of the matrix. For this purpose, if appropriate, the first pump of the matrix which is assigned to the first row and the first column and which lies on the diagonal may also belong. This results from the row or column sorting.

According to a development of the method according to the invention, it is determined by evaluating the matrix how many pumps of the respective considered pump are connected upstream hydraulically. For this purpose, the number of increasing changes of the hydraulic variables in the columns under the diagonal or in the lines above the diagonal of the matrix is detected. This number corresponds to the number of pumps upstream of the respective pump, whereby no statement is made about the hydraulic connection of the upstream pumps. According to a variant of the method in which the matrix is formed in the same way as described above, it can be determined which pumps are hydraulically next to each other and which are hydraulically connected in series, based on the number of increasing changes in the hydraulic variables in each row below or in each column above one Divide matrix and extending from one to the other matrix axis diagonal. In this case, according to a development of the method according to the invention, the number of increasing changes in the hydraulic variables in the rows below the diagonal or in the columns above the diagonal of the matrix can be used to determine the number of pumps which are hydraulically connected downstream of the respective pump thus the number can be assigned.

The inventive method can be evaluated when hydraulic variables of the pump, either be carried out by the fact that the flow rate of the pump is detected or alternatively the pressure or the differential pressure of the pump. If the determination of the pressure changes to take place, according to the invention, in the same manner as described above, a matrix is formed, in which the hydraulic changes of at least one hydraulically independent part of the plant are detected, whereby line by line to each pump in their control for the promotion with changed Pressure is given to resulting changes in the hydraulic magnitude of this and the other pumps and wherein each pump is assigned a column. The rows are sorted according to their number of decreasing changes (-1) ascending from top to bottom and the columns according to their number decreasing changes from left to right and then using the number of decreasing changes in the hydraulic size in each column below or in each row one dividing the matrix and determining from one to the other matrix axis extending diagonal, which pumps are hydraulically next to each other and which are hydraulically connected in series. Here, too, the diagonal forms a symmetrical division of the matrix and passes through the fields always indicated as increasing change, which in the row and column respectively relate to the same pump. These fields are not counted as in the above, even in the subsequent evaluation.

In this case, an equal number of decreasing changes in the hydraulic variables in the columns below the diagonal or in the lines above the diagonal of the matrix indicates the juxtaposition of the corresponding pumps.

A different number of decreasing changes in hydraulic sizes in columns below the diagonal or in rows above the diagonal of the matrix indicates the series connection of the respective pumps.

If a line below the diagonal does not have a decreasing change in hydraulic magnitudes, or a column above the diagonal of the matrix, then this determines the immediate assignment of the corresponding pump to a consumer or group of consumers.

The number of decreasing changes of the hydraulic variables in the columns below the diagonal or in the lines above the diagonal of the matrix indicates according to a development of the method according to the invention the number of the respective pump hydraulically upstream pumps.

Based on the number of decreasing changes in the hydraulic variables in each column below or in each row above a diagonal dividing the matrix and extending from one to the other matrix axis, according to a further development of the method according to the invention, it is alternatively determined which pumps are hydraulically connected next to one another and which are hydraulically connected in series. In this case, the pumps, which have the same number of decreasing changes in the hydraulic variable in the column below or in the row above the diagonal of the matrix, are hydraulically connected next to one another and connected in series with different numbers.

According to a development of the method according to the invention, the number of decreasing changes of the hydraulic variables in the rows below the diagonal or in the columns above the diagonal of the matrix indicates the number of pumps in each case hydraulically connected downstream.

It thus becomes clear that the above-described matrix unambiguously determines the functional relationship of the pumps when a hydraulic change in size is detected at each pump. When detecting hydraulic changes at the consumer or a consumer group, it may be necessary, as described above, in addition to differentiate pump groups by means of the change of a hydraulic size of the pump to the effect whether they are connected in parallel or in series.

The energy optimization method according to the invention and also the above-described method for determining the functional relationship of the pumps can be realized by an electronic control and regulating device, which is typically designed as a digital control and regulation unit and has a data connection to the pump. Such a data connection can be made, for example, wirelessly via radio or wired in the manner of a network connection between the pump and the control unit. The control unit can also form part of a pump. It may be particularly useful when a control unit is provided, which is data-connected to the pumps, so that practically any pumps can be used for the application of the method according to the invention, if they are modified accordingly, ie at least one data connection for connection have the control unit. It is, however, particularly expedient if the pumps themselves are designed such that they have the variables required for the control method, in particular the magnitude e _h , which is the quotient of the change in the absorbed power P for changing the delivery height h and _eq which determines the Quotient of the change in the absorbed power P and the change in the flow rate q indicating the pump provide. These values are typically readily available in the control electronics in the case of speed-controllable pumps, which is why it would only be exceptionally sensible to determine them separately in an external control unit. Furthermore, the control electronics of the pump should generate a signal S, if and as long as the respective pump has reached its power saturation. It is understood that in digital signal processing, a signal is always present and then a value of 0 to 1 or vice versa is set, which represents the saturation.

According to one embodiment of the invention, it may be expedient to provide a part of the control unit on the pump side, for example, for energy optimization parallel pumps and on the other hand only provide the part of the control unit as an external device, which for the optimization of energy optimization circuits or the entire plant serves.

Figur 1

ein Schaltbild einer hydraulischen Anlage,

Figur 2

die Anordnung der Energieoptimierungskreise in der Anlage gemäß Figur 1,

Figur 3

das hydraulische Schaltbild einer anderen hydraulischen Anlage,

Figur 4

die Lage der Energieoptimierungskreise in der Anlage gemäß Figur 3,

Figur 5

ein Energieoptimierungsschaltbild, bei dem 4 Pumpen miteinander verschaltet sind und

Figur 6

ein Energieoptimierungsschaltbild, bei dem 5 Pumpen miteinander verschaltet sind.

The invention, insofar as it relates to the optimization method, is explained in more detail below with reference to exemplary embodiments. Show it

FIG. 1

a circuit diagram of a hydraulic system,

FIG. 2

the arrangement of the energy optimization circuits in the system according to FIG. 1 .

FIG. 3

the hydraulic circuit diagram of another hydraulic system,

FIG. 4

the location of the energy optimization circuits in the system according to FIG. 3 .

FIG. 5

an energy optimization diagram in which 4 pumps are interconnected and

FIG. 6

an energy optimization diagram in which 5 pumps are interconnected.

The basis of FIG. 1 For example, the hydraulic system shown represents a heating system which has a total of 5 consumers or consumer groups V1, V3, V6, V7 and V10, as well as 14 speed-controllable centrifugal pumps pu1 - pu14. In order to optimize consumption of this plant with regard to the operation of the pumps, energy optimization circuits are first of all to be formed. For this purpose, it must first be determined which pumps form pilot pumps, ie, it is necessary to determine the pumps which are directly assigned to a consumer. In the diagram according to FIG. 1 these are the pumps pu1, pu2, pu3, pu6, pu7 and pu10. The pumps pu1 and pu2 are connected in parallel and upstream of the load V1, ie directly assigned. The pumps pu3, pu6, pu7 and pu10 are connected upstream of the corresponding consumers V3, V6, V7 and V10.

To form energy optimization circuits, one or more pilot pumps and the downstream pumps that feed into them are now assigned to an energy optimization circuit. A first energy optimization circuit EK1 is formed by the two pilot pumps pu1 and pu2, which are arranged parallel to one another, as well as the upstream pump pu12 which feeds them. A second energy optimizing circuit EK2 is formed by the pilot pump pu3 and the preformed pump pu1 conveying it. A third energy optimization circuit EK3 is formed by the three pilot pumps pu1, pu2, pu3 and the upstream pumps pu4 and pu5, which are arranged in series with one another. A fourth energy optimization circuit EK4 is formed by the two pilot pumps pu6 and pu7 and the upstream pump pu13. Furthermore, a fifth energy optimization circuit EK5 is formed, which is formed by the pilot pumps pu1, pu2, pu3, pu6 and pu7 and the upstream pumps pu8 and pu9. The other pumps, which are also upstream of these pilot pumps, are not assigned to this energy-optimizing circuit EK5 since they are already assigned to other energy-optimization circuits. Finally, an energy-optimizing circuit EK6 is formed, which consists of the pilot pump pu10 and the pump 14, which feeds into this pump.

The energy optimization circuits EK1 - EK6 are now energy-optimized one after the other, which energy-optimized the entire system in terms of pump operation. In this case, a size e _{h is first} determined in each energy optimization circuit with respect to the pilot pumps by determining the quotient from the change in the absorbed pump power P to the change in the delivery head h during plant operation by these pumps. Are in a power optimization circuit comprises two or more pilot pumps exist, such as in the circles EK1, EK3, EK4 and EK5, the variables are e _h the pilot pump is added and with the size e _h of each of the upstream pumping equated for itself. The upstream pumps are controlled with a correspondingly variable speed until these e-values are the same and thus the energy optimization circuit is optimized. Thus, for example, the e-values of the pumps PU6 and PU7 are added in the energy-optimizing circuit EK4 and the pump PU 13 is variably controlled until the magnitude e _{h of} the pump PU 13 corresponds to the sum of the magnitudes e _{h of} the pumps PU6 and PU7.

In the energy optimization circuit 3, the size e _{h of} the pumps pu1, pu2 and pu3 are added in an analogous manner and equated successively with the size e _{h of} the pump pu4 and the pump pu5 and the pumps pu5 or pu4 are variably controlled until these values coincide ,

If EK5 two pumps are connected in parallel as in the energy optimization circuit as PU8 and PU9 the case with the pump, then the pumps connected in parallel are first energy-optimized to each other by size e is determined _q in the operation of each of these pumps, which the Change of absorbed power P to change the flow rate q indicates. The pumps pu8 and pu9 are then controlled in their speed by variance until the sizes eq of both pumps match. For the energy optimization within the energy optimization circuit EK5, the pumps pu8 and pu9 are then considered as a pump. For this purpose, a size e _{h is} determined by these pumps by the quotient from the change of the absorbed power P of a pump to the change of the delivery head h to each of the pumps is detected and added. The energy optimization within the energy optimization circuit EK5 is then continued by equating this magnitude e _{h of} the two pumps pu8 and pu9 with the sum of the corresponding e _h variables of the pilot pumps.

The basis of FIG. 3 shown hydraulic system corresponds in its function substantially to the above and with reference to FIG. 1 shown, but with the difference that the pumps pu1 - pu14 not there as in FIG. 1 in the run to the consumers V, but in the return are switched to it. The pilot pumps are thus connected on the suction side with the consumers V, the pumps downstream of the pilot pumps are connected downstream hydraulically. Thus, in an analogous manner, the pilot pumps pu1 and pu2 which are assigned to the consumer V1, the pilot pumps pu3, pu6, pu7 and pu10, which are assigned to the consumers V3, V6, V7 and V10. The upstream pumps are correspondingly similar to those in FIG. 4 illustrated energy optimization circuits EK1 - EK5 clarify.

Based on FIG. 5 It is illustrated how four hydraulically interconnected pumps PUI - PUIV are connected with each other and how the energy optimization takes place. The hydraulic connections are shown by broken lines and the data connections in solid lines. In the illustrated embodiment, the pump PUIV is connected upstream of the pumps PUI, PUII and PUIII, the pumps PUI, PUII and PUIII being connected in parallel and representing pilot pumps in relation to a consumer connected on the output side. It is in the FIG. 5 each pump a speed controller 10 and an energy optimization unit 11 assigned. The upstream pump PUIV is associated with an energy optimization unit 11a, which is designed as an external unit, whereas the units 11 form part of the respective pump. Since the pumps PUI, PUII and PUIII are connected in parallel, they are first optimized for each other by the pumps are controlled such that their sizes eq, which by the difference quotient or differential quotient of power consumption P and flow rate q each Pump are formed to be equated, ie the pumps are controlled by means of the speed controller 10 as long as variable speeds until these values match. It is how the representation according to FIG. 5 illustrates, always one of the parallel pumps except the energy optimization, which ensures the generation of the applied by the pump discharge pressure, the other two pumps can then be energy-optimized in terms of flow. In the illustration according to FIG. 5 the pump PUI is switched as a pilot pump for pressure control while the pumps PUII and PUIII share the required flow rate together with the pump PUI. The upstream pump PUIV fulfills a pressure task, which is why the energy optimization takes place via the magnitude e _h , which is formed by the difference or differential quotient of power consumption P and delivery height h.

As the illustrations make clear, it is expedient if all the pumps participating in the process generate both a signal eq and a signal e _h , the signal eq being used with pumps connected in parallel and the signal e _{h being used} with pumps connected in series. In parallel-connected pumps, in addition to optimizing the group of parallel-connected pumps, the signal e _{h is} used to optimize the group in combination with the other pumps, virtually as a single pump.

Based on FIG. 6 is an energy optimization process of 5 pumps PUI, PUII, PUIII, PUIV and PUV shown, wherein as in the embodiment of FIG. 5 the pumps PUI, PUII and PUIII are connected in parallel and are connected upstream of the pilot pumps PUIV and PUIV. Here, too, an internal optimization by means of the energy optimization devices 11 via the signals eq and subsequently an energy optimization of the pump group, consisting of the pumps PUI, PUII, PUIII via the energy optimization device 11 to the pilot pumps PUIV and PUV. The quantities e _{h of} the pumps PUIV and PUV are added and equated to the sum of the e _h values of the pumps PUI, PUII, PUIII connected in parallel and connected upstream of the pilot pumps, and the latter pumps are actuated in a variable-speed manner until the abovementioned e _h sizes match and thus one Optimization of this energy optimization cycle is done.

In the drawings, for the sake of better understanding, the quantities e _{h are} dP / dh and the quantities eq are dP / dq / dq respectively provided with the number corresponding to the numbering of the corresponding pump.

Figur 7a

ein hydraulisches Schaltbild einer Anlage mit mehreren Pumpen und Verbrauchern

Figur 7b

eine Matrix zu der Anlage gemäß Figur 7a,

Figur 8a

ein Schaltbild von vier nebeneinander angeordneten Pumpen,

Figur 8b

das zeitliche Verhalten der Pumpen bei Druckerhöhungen,

Figur 9a

ein Schaltbild einer Pumpengruppe aus nebeneinander und hintereinander angeordneten Pumpen,

Figur 9b

das Verhalten der Pumpen bei Ansteuerung mit geänderter Drehzahl,

Figur 10a

ein Schaltbild von drei parallel angeordneten Pumpen,

Figur 10b

das Verhalten der Pumpen bei Drehzahländerung,

Figur 11a

ein Schaltbild von drei hintereinander angeordneten Pumpen,

Figur 11 b

das Verhalten der Pumpen bei Ansteuerung mit einer Drehzahländerung,

Figur 12

ein hydraulisches Schaltbild einer hydraulischen Anlag entsprechend Figur 7 jedoch mit pumpenseitiger Sensoranordnung,

Figur 13

eine erste Matrix zu der Anlage gemäß Figur 12 und

Figur 14

eine zweite Matrix zu der Anlage gemäß Figur 12.

The invention, as far as the method for determining the functional relationship of pumps in a plant, is described below with reference to Fig. 7 to 14 explained in more detail. Show it

Figure 7a

a hydraulic circuit diagram of a system with several pumps and consumers

FIG. 7b

a matrix to the plant according to Figure 7a .

FIG. 8a

a circuit diagram of four juxtaposed pumps,

FIG. 8b

the temporal behavior of the pumps at pressure increases,

FIG. 9a

a circuit diagram of a pump group of juxtaposed and successively arranged pumps,

FIG. 9b

the behavior of the pumps when actuated with changed speed,

FIG. 10a

a circuit diagram of three parallel pumps,

FIG. 10b

the behavior of the pumps when the speed changes,

FIG. 11a

a circuit diagram of three successively arranged pumps,

FIG. 11 b

the behavior of the pumps when driven with a speed change,

FIG. 12

a hydraulic circuit diagram of a hydraulic system accordingly FIG. 7 however with pump-side sensor arrangement,

FIG. 13

a first matrix to the plant according to FIG. 12 and

FIG. 14

a second matrix to the plant according to FIG. 12 ,

The basis of FIG. 7 and FIG. 12 shown hydraulic system is not to be explained in detail here heating system. It is equipped with a total of 11 pumps PU1 - PU11. These altogether 11 pumps supply 6 consumers V1 - V6. These consumers may be single consumers, but are typically consumer groups, such as a network of parallel heat exchangers, as is customary in housing for space heating, which may also be connected in groups in parallel and / or in series. Each consumer is assigned a sensor S1, S3, S6, S7, S10 or S11, which detects the pressure dropping at the consumer.

The plant consists of two hydraulically independent plant components, namely the in Figure 7a System part shown on the bottom right, consisting of the pump PU 11 and the consumer V6 and the rest of the system component. In the remaining part of the system, at the lowest level, a pump PU10 supplies a load V5, in parallel two pumps PU8 and PU9 connected in parallel feed via a downstream one Pump PU6 the consumer V3 and in parallel via a downstream pump PU7 the consumer V4. The pumps PU1, PU2 and PU3 are supplied via the pumps PU5 and PU4 connected in series, which in turn, however, supply the load V1 or the load V2 to the consumer in parallel. This arrangement is chosen arbitrarily and serves exclusively to illustrate the method according to the invention.

To carry out the method, all pumps PU1 to PU11 are first of all actuated at a constant rotational speed, typically an average rotational speed which is selected so that the system is operated as intended, but reserves are present, so that the pumps may be in contact with the increased rotational speed can be controlled. The pumps are typically frequency converter-controlled heating circulation pumps as they are customary in the market.

All pumps are operated at a constant speed, this speed should be constant relative to the respective pump, among each other, the speeds may of course differ. If one of the pumps has to be controlled with a different speed during the process due to the system's demand, this can be done if the correspondingly changed speed is taken into account mathematically. During this control with constant speed, pressures are determined at the sensors S1, S3, S6, S7, S10 and S11. There will now be a first pump, e.g. the pump PU1 is controlled with a changed speed, for example an increased speed, and by means of the sensors S1, S3, S6, S7, S10 and S11, the changes or non-changes that may then be detected are detected.

For this purpose, a matrix is expediently set up as in FIG. 7b is shown. In the matrix, the pumps PU1-PU 11 are on one, here vertical axis and on the other. Here the horizontal axis sensors S1 - S11 listed and then to capture in the resulting fields, if and possibly what hydraulic changes result when driving a pump with increased speed. A categorization into 0, -1 and 1 takes place, where 0 stands for no change, 1 for an increasing hydraulic variable and -1 for a falling hydraulic variable.

When driving the pump PU1 with increased speed thus results according to the FIG. 7b at the sensor S1 an increasing pressure difference, at the sensor S3 a falling pressure difference at the sensor S6 a falling pressure difference at the sensor S7 a falling pressure difference and at the sensor S10 also a falling pressure difference compared to the feedforward of this pump PU1 with lower speed. The sensor S11 does not change, since it concerns a part of the plant which is not hydraulically connected to the pump PU1. When these changes are detected, the pump PU1 is again brought down to the previously activated constant first speed, after which the pump PU2 is now driven at an increased speed and the changes resulting in the sensors S1-S11 are then entered in the matrix. This is done subsequently with all pumps until the matrix is completely as in FIG. 7b is executed.

The matrix representation is listed here only for simplified numerical representation, but in principle not required for the evaluation. It can now be determined on the basis of the control first of all that the pumps PU1 - PU10 have no influence on the sensor S11 and thus the consumer V6. Conversely, the pump PU 11 has no influence on the consumers V1 - V5, with the result that these must be two independent parts of the plant, the pump PU11 obviously only supplies the consumer V6.

In the remaining part of the plant, which has the pumps PU1 - PU 10, it is now first examined which pumps are arranged in groups of pumps, that is, which pumps are connected in parallel or in series to form a group. The pumps are switched to groups, which trigger the same hydraulic changes on the consumer side as they change their speed. This is true as in the matrix FIG. 7b for the pumps PU8 and PU9, for the pumps PU1 and PU2 as well as for the pumps PU4 and PU5. These pumps are thus identified as groups, so it is still necessary to determine whether these are connected in parallel or in series, which will be described below.

It is then determined which pumps affect only one consumer or only one consumer group according to the speed change in a speed change, ie pressure increasing at a speed increase and pressure-reducing influence at a speed reduction. As in the embodiment, the basis of FIG. 7 is shown, it is assumed that the pump in process step b are driven at an increased speed compared to the previously lower constant speed, these pumps arise here in that they have only a positive 1 in the row. These are the pumps PU 1, PU 2, PU 3, PU 6, PU 7, PU 10 and of course PU 11, which belongs to the other part of the plant. These pumps are directly associated with a consumer, ie they supply the consumer without the interposition of other pumps.

Based on these assignments, however, it can be determined not only which pumps are directly associated with a consumer, but also which consumers are supplied by which pumps at all. So it can be seen that the pump PU10 only the consumer V5 and this applied directly. With regard to the pump group PU8 and PU9, it can be seen that they influence the sensors S1, S3, S6 and S7 in the same direction, ie that a higher pressure drops at these sensors when the pump is actuated at an increased rotational speed, ie an increasing pressure Pressure change is given. This means that the pumps PU8 and PU9 feed the consumers V1 - V4, but only indirectly, ie that other pumps must be interposed. With regard to the pumps PU4 and PU5 can be found in the same way that they supply the consumers S1 and S3, but also indirectly because the consumers V3 and V4 are supplied directly from the pump PU6 or PU7, the pumps PU4 and PU5 as a pump group However, these consumers do not influence in the same direction shows that the pump group PU4 and PU5 and the pump PU6 and the pump PU7 are connected side by side with the pumps PU6 and PU7 are assigned to the respective consumers V3 and V4 while the pump group PU4 and PU5 consumers V1 and V2 applied, but also not directly.

In so far now only to determine how the pump groups are interconnected. These three groups of pumps PU8 and PU9, PU4 and PU5 as well as PU1 and PU2 must therefore still be investigated. For this purpose, however, additional sensors are needed, which detect the differential pressure of the respective pumps of the pump group or the flow. In the embodiments according to the FIGS. 8 and 9 Differential pressure sensors are used parallel to the pump whereas in the embodiments according to the FIGS. 10 and 11 Volumetric flow sensors so-called. Flow meter associated with the pump. Regardless of which sensors are used, the method described above is again used to determine the arrangement of the pump in a pump group, ie, the pumps are first as based on the FIGS. 10 and 11 shown, operated at a constant speed, after which a pump, here the pump PU1 is driven at an increased speed. Based on the changing volume flow of these and the other pumps can now be determined whether the arranged to a pump group pumps are connected in series or in parallel. In parallel connection according to FIG. 10a results in control of a pump here the pump PU1 with increased speed ω 1 of this pump, an increased flow q1 whereas the other two pumps PU2 and PU3 continue to run at the previous constant speed, but have a lower flow q2 or q3. It follows immediately that the pumps must be connected in parallel, otherwise the flow rates would have to increase, as determined by FIG. 11 it is clear where three pumps PU1 - PU3 are connected in series. If the pump PU1 is actuated here at an increased rotational speed ω 1, then, despite the constant rotational speed of the pumps PU2 and PU3, there is an increased flow rate q1, q2 and q3 of all three pumps.

If the arrangement of the pumps by means of pressure sensors so differential pressure sensors to be determined parallel to the pump, then one of the pumps of a pump group after all have been driven to generate a constant pressure, one of the pumps is driven to generate an increased pressure. This is in the examples according to FIG. 8 and FIG. 9 in each case takes place at the pump PU1. How the time course of the change of the hydraulic variables is, is the FIG. 8b refer to. After the pressure jump of the pump PU 1, the pressure at the pumps PU2, PU3 and PU4 remains virtually unchanged, the speeds of the pumps PU2 and PU3 drop slightly rising pressure, which suggests a parallel connection, whereas the speed of the pump PU4 at the same Pressure rises, indicating that this pump is not one of the pumps in parallel. Analog results in the series connection of the pumps PU1, PU2 and PU3 to a group a pressure change only in the pump PU1 and all other pumps only a speed change, namely upwards.

As the above explanations clarify, thus the circuit diagram according to Figure 7a be completely determined. Since in the above-described method only one sensor or each consumer group is assigned a sensor, a separate pump-side sensor system must be used to determine the arrangement of the pumps in the pump groups.

In so far often is cheaper to perform the inventive method exclusively with pump-side pressure, differential pressure or flow sensors, as shown by the FIGS. 12-14 is shown. This process proceeds in the same way, ie first all pumps are driven at a constant speed in a first step and then in a second step subsequently all pumps individually and sequentially with contrast, changed speed, typically increased speed. The resulting changes are captured in a matrix as determined by FIG. 13 for the flow measurement of the pumps and by means of FIG. 14 for the differential pressure measurement on the pumps is shown. The matrix is the same as the one from FIG. 7b is formed, ie 0 stands for no change in the hydraulic size of the corresponding sensor when driving the corresponding pump with increased speed, 1 stands for increasing change and -1 for falling change.

For the evaluation of the matrix according to FIG. 13 however, it is necessary to sort them by lines first. When detecting volume flow changes as shown in FIG. 13 are recorded, the sorting of the lines is performed according to the number of increasing changes in ascending order from top to bottom. Thus, the top line concerning the pump PU7 has a 1, namely at q 11. Also, the line PU10 arranged underneath only knows one 1 namely at q10. Lines PU7 and PU6 each have 3 increasing changes, lines PU1. PU2 and PU3 each 5 increasing changes, the line PU4 and PU5 7 increasing Changes and the line PU8 and PU9 8 increasing changes. According to this order, the rows are sorted from top to bottom in ascending order. Each line is assigned a pump and each column of the pump associated sensor. The columns are sorted in ascending order in the same way as the pumps from left to right, so that a mirror symmetry of the matrix with respect to a diagonal D formed by the fields affecting the same pump. This diagonal extends from top left to bottom right in the matrix starting from the field PU11 q11 to the rock PU9, q9.

The functional relationship, d. H. The structure of the system can be determined directly using this matrix. Thus, first of all, in the same way as in the first exemplary embodiment, it can be ascertained from the zeros in the first column below the diagonal or in the first row above the diagonal that the pumps PU1-PU10 belong to a different part of the plant than the pump PU11 this pump only affects its own sensor q11.

Based on the number of increasing changes, ie the numbers 1 of the flow in each column under the diagonal D or in each row above the diagonal D, which divides the matrix, which pumps hydraulically side by side and which are hydraulically connected in series. An equal number, as for example in columns q7 and q6 and q5 in FIG. 13 occurs under the diagonal D, says that these pumps are arranged side by side, whereas a contrasting number, such as at q4 -here are three- indicates that this pump PU5 is not next to, but behind one of the aforementioned pump. How the arrangement is given results from the number of increasing changes. In this case, the number of increasing changes in the hydraulic variables in the columns below the diagonal or mirror-symmetrically in the lines above the diagonal of the matrix indicates the number of pumps connected hydraulically upstream of the respective pump. Thus, for example, the pump PU1, which is assigned to the sensor q1, in the column q1 below the diagonal with four ones, ie four increasing changes in the hydraulic variables, which means that four pumps of the pump PU1 are connected upstream. This can be determined for each of the pumps.

Furthermore, it can be determined which of the pumps are directly associated with a consumer or a consumer group, namely, these are the pumps, in which no increasing change in the hydraulic variables is listed in a row below the diagonal or a column above the diagonal of the matrix , This applies, for example, to the pump PU7, in its associated line in FIG. 13 below the diagonal are only the numbers 0 and -1, in the same way for PU6, there are the numbers 0, -1, -1, etc. Based on these provisions can thus be determined which pumps are connected side by side, how many pumps of the respective Pump are hydraulically connected upstream and connect which pumps directly to a consumer or a consumer group. Thus, the circuit arrangement according to FIG. 12 clearly determined.

Furthermore, in FIG. 13 also be determined based on the number of increasing changes in the hydraulic variable in each row under or in each column on the diagonal D of the matrix, which pumps are hydraulically connected side by side and which are connected in series. The number of increasing changes (+1) indicates the number of pumps which are hydraulically connected downstream of this pump. So points in FIG. 13 the pump PU8 in the line 7 ones below the diagonal D on, which means that this pump seven pumps are connected downstream. These are the pumps PU1 - PU7. You read in FIG. 13 Under PU4, the line below the diagonal D results in 3 ones, ie three downstream pumps. It is like the circuit diagram according to FIG. 12 clarified by the pumps PU1 - PU3.

In an analogous manner, the evaluation of the matrix is carried out according to FIG. 14 in which instead of the flow changes q the pressure changes s are indicated. However, not the increasing changes 1 but the decreasing changes -1 are used here for the evaluation, but otherwise the evaluation takes place in the same way as with reference to FIG FIG. 13 described.

Claims (17)

1. A method for energy optimisation on operation of several speed-controllable centrifugal pumps in a hydraulic facility, in which pumps are activated with a varying rotational speed for energy optimisation, in which it is firstly determined which pumps as pilot pumps are directly assigned to a consumer and which pumps are subordinate to the pilot pumps, whereupon the subordinate pumps are activated with varying rotational speeds for energy optimisation, characterised in that one or more energy optimisation circuits are formed, which each consist of one or more pilot pumps and one or more subordinate pumps which deliver into the pilot pumps or are fed from these, wherein subordinate pumps are each assigned to only one energy optimisation circuit, whereupon the energy optimisation circuit or circuits are energy-optimised, wherein an energy optimisation circuit is optimised by way of a variable e being determined for each pump of the energy optimisation circuit, said variable e being determined by the quotient of the change of taken-up power and the change of delivered hydraulic power of the pump and the variables e of the pilot pumps are added and are herewith brought to agree with the variable e of each of the pumps of the energy optimisation circuit which are connected upstream or downstream of these by way of variance of the activation of the pumps which are connected in series upstream or downstream, wherein pumps which are connected upstream or downstream and which are connected in parallel are considered as one pump.
2. A method according to claim 1, characterised in that an energy optimisation circuit comprises one or more pilot pumps and one or more subordinate pumps which directly deliver into at least one pilot pump or are fed directly from this.
3. A method according to claim 1 or 2, characterised in that an energy optimisation circuit comprises all the pilot pumps, into which the one or more subordinate pumps deliver or from which these are fed.
4. A method according to one of the preceding claims, characterised in that the electrical input power P of the drive motor is used as the taken-up power.
5. A method according to one of the preceding claims, characterised in that the delivery head h of the pump is used as a measure for the delivered hydraulic power.
6. A method according to one of the claims 1 to 4, characterised in that the delivery rate q of the pump is used as a measure of the delivered hydraulic power.
7. A method according to one of the preceding claims, characterised in that pumps connected in parallel are activated such that the variable e_q of the pumps which are connected in parallel is equally large, wherein the variable e_q is formed by the quotient of the change of taken-up power P and the change of the delivery rate q of the pump.
8. A method according to one of the preceding claims, characterised in that pumps which are connected in parallel are considered as one pump and concerning which the variable e_h for this one pump is formed by the addition of the quotients of the change of taken-up power P and the change of the delivery head h of each of the pumps which are connected in parallel.
9. A method according to one of the preceding claims, characterised in that a variable e_h of each of the pumps connected in series is used for energy optimisation, said variable being formed by the quotient of the change of taken-up power P and the change of the delivery head h of the pump.
10. A method according to one of the preceding claims, characterised in that a pump is no longer activated in a power-increasing manner on or directly before reaching its power saturation.
11. A method according to one of the preceding claims, characterised in that at least one pump is changed in its rotational speed, and at least one functional relationship of the facility is determined from the hydraulic reaction resulting therefrom, for determining the functional relationship of pumps in the facility.
12. A pump for carrying out a method according to one of the preceding claims, characterised by an electric motor and a centrifugal pump driven by this, with an electronic speed controller with control electronics, at which the control electronics produce a signal which represents a variable e which is determined by the quotient of the change of taken-up power P and the change of a hydraulic output variable or of a variable of the pump which is influenced by this.
13. A pump according to claim 12, characterised in that the hydraulic output variable for determining the variable e_h is the delivery head h of the pump.
14. A pump according to claim 12 or 13, characterised in that the hydraulic output variable for determining the variable e_q is the delivery rate q of the pump.
15. A pump according to one of the preceding claims, characterised in that the control electronics produce a signal S which represents the power saturation.
16. A pump according to one of the preceding claims, characterised in that a control and regulation unit is provided for carrying out the method according to one or more of the claims 1 to 11.
17. A pump according to claim 16, characterised in that the control and regulation unit is a digital one.

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