EP2562424B1 - Method and equipment for controlling a multipoint fluid distribution system - Google Patents

Method and equipment for controlling a multipoint fluid distribution system Download PDF

Info

Publication number
EP2562424B1
EP2562424B1 EP12382344.5A EP12382344A EP2562424B1 EP 2562424 B1 EP2562424 B1 EP 2562424B1 EP 12382344 A EP12382344 A EP 12382344A EP 2562424 B1 EP2562424 B1 EP 2562424B1
Authority
EP
European Patent Office
Prior art keywords
pressure
pump
point
consumption
demand
Prior art date
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.)
Active
Application number
EP12382344.5A
Other languages
German (de)
French (fr)
Other versions
EP2562424A3 (en
EP2562424A2 (en
Inventor
Gabriel Alejandro Bica Caffera
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Gidelmar S A
Gidelmar SA
Original Assignee
Gidelmar S A
Gidelmar SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Gidelmar S A, Gidelmar SA filed Critical Gidelmar S A
Priority to EP12382344.5A priority Critical patent/EP2562424B1/en
Publication of EP2562424A2 publication Critical patent/EP2562424A2/en
Publication of EP2562424A3 publication Critical patent/EP2562424A3/en
Application granted granted Critical
Publication of EP2562424B1 publication Critical patent/EP2562424B1/en
Application status is Active legal-status Critical
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D15/00Control, e.g. regulation, of pumps, pumping installations or systems
    • F04D15/0066Control, e.g. regulation, of pumps, pumping installations or systems by changing the speed, e.g. of the driving engine

Description

    Field of the Art
  • In a first aspect, the present invention relates to a method for controlling a multipoint fluid distribution system and particularly to a method which comprises controlling the fluid supply pressure for a plurality of consumption points which may require different supply pressures.
  • In a second aspect, the present invention comprises a piece of control equipment suitable for implementing the method of the first aspect of the present invention.
  • The invention provides an intelligent strategy which enables automatically adapting the operating conditions of a centrifugal pump and adjusting its performance to the various needs of different consumption points (variable demand), offering an adequate pressure at all times to said consumption point or points and further allowing an optimised use of water and energy resources.
  • Background of the Invention
  • The concern for water and energy saving is inspiring new household water pressurising and distributing systems in order to obtain a greater economic saving.
  • Some prior inventions disclose systems and/or methods for pressurising or controlling water pumps.
  • US2005095150A1 describes a centrifugal multi-stage pump including a microcontroller implementing a series of algorithms for controlling the pump operation by varying the rotating speed of its motor depending on the various parameters, such as the discharge height, the rotating speed of the motor of the pump, the supply pressure and the presence or absence of supply, temperature, etc.
  • US646446 B2 relates to a controller for controlling operating parameters, such as the flow, speed or pressure of a centrifugal pump including a memory where data indicative of one or more operating conditions are recorded, one or more sensors fixed to the pump for detecting an operating condition and generating a signal indicative of same and a processor running an algorithm using the recorded data and the signal generated by the sensor to in turn generate a control signal representative of a correction factor to be applied to the pump which is, for example, relative to a variation in the rotating speed of the motor of the pump.
  • EP1286240B1 describes a method for obtaining a curve of discharge height versus flow rate [Hinstalation(Q)] or electric consumption versus flow rate [Pinstalation(Q)] descriptive of the setpoint values of an installation for regulating the pumping capacity of a pump actuated by an electric motor the rotating speed of which is regulated, wherein a physical magnitude representative of the momentary pumping capacity of the pump is detected by means of a differential pressure sensor installed at the consumption point and a controller with an electric signal proportional to that physical magnitude is input as an actual value by means of which controller the rotating speed of the electric motor and thus the pumping capacity of the pump is regulated with the help of the curve descriptive of the setpoint values of the installation.
  • EP1286240B1 proposes obtaining the curve descriptive of the setpoint values which takes into consideration, at least by sections, the installation losses depending on the pumped flow rate by means of the opening of one or more consumption point every time, the detection of a functional service parameter of the consumption point, the momentary pump power variation until the consumer service parameter acquires a pre-set value and the obtainment of a pair of pump parameters which is representative of the momentary pumping capacity of the pump (such as H and Q or P and Q) at the time in which said pre-set value is acquired and the storage of those values. Finally, a function is calculated by means of a mathematical curve plotting method from the saved values of the pair of pump parameters and that function is stored as a [Hinstalation(Q)] curve descriptive of the setpoint values of the installation.
  • US 5540555 describes a multipoint fluid distribution system which at least includes a primary pump and a variable speed secondary pump by means of which the fluid supply pressure for a plurality of consumption points requiring different supply pressures taken as setpoint pressures for said control is controlled and which includes a plurality of pressure sensors arranged in part of or in all said consumption points for remotely measuring the supply pressure and varying the values of the setpoint pressures depending on the measured pressures, varying the speed of the secondary pump depending on said setpoint pressure values.
  • Summary of the Invention
  • The invention provides an alternative to the mentioned state of the art by means of an intelligent distribution system which allows adapting the operating condition and the performances offered by a centrifugal pump to the needs of demand at all times offering an suitable pressure according to the geometrical origin of the consumption point and allowing facilitating the user to modify (within pre-established margins) the supply conditions by selecting a specific performance level.
  • The objective of the invention is to achieve, by means of the method, a pumping control system and a centrifugal pump proposed to achieve a saving in pumped fluid and power when the centrifugal pump works in a minimum operating conditions suitable for providing sufficient pressure in the consumption points, thereby increasing the durability of the pumping installation.
  • To that end, a method for controlling a multipoint fluid distribution system which according to the prior art comprises:
    • setting the working conditions of the motor of a centrifugal pump of the distribution system by determining a fluid supply pressure for feeding a plurality of consumption points which may require different supply pressures taken as pump setpoint pressures, and
    • measuring the supply pressure in at least one point of said fluid distribution system and varying the values of said setpoint pressures depending on the measured pressure.
  • According to the principals of the invention, said point of the distribution system where the mentioned pressure measurement is performed is a point previous to said consumption points through which the pumped fluid directed towards said consumption points flows and it is a preferably a point inside the pump or contiguous thereto, for example located in a discharge conduit close to same.
  • The method of the invention comprises performing the following steps in sequence:
  1. a) permanently acquiring a successive series of supply pressure values (Pi) measured in said previous point;
  2. b) successively varying the pump rotating speed for compensating said pressure variation in response to a pressure variation detected in said previous point as a result of said measurements of step a);
  3. c) detecting that at least two of said pressure values (Pi1), (Pi2), measured in said previous point increases or decreases in response to said variation of the pump rotating speed, and obtaining (in a diagram of flow discharge height) a curve of demand by calculating the coefficients of a known mathematical function descriptive of said curve of demand relating discharge height and flow rate of the pump, making said coefficient calculations from said measured pressure values (Pi1), (Pi2) and of corresponding calculated flow rate values;
  4. d) determining a consumption point which is equal to the value of the discharge height obtained when applying a flow rate value equal to zero in said mathematical function descriptive of the curve of demand with calculated coefficients (intersection of said curve of demand with the y-axis reflecting the discharge height);
  5. e) adopting a pump rotating speed providing a pump setpoint pressure depending on said consumption point determined in step d), and
  6. f) restarting steps b) to e) in the event that another pressure variation is detected in said succession of values measured in step a) (which is performed at all times), indicative of an alteration in the demand.
  • Said variation of pump rotating speed of step b) will be an increase in speed if the measured pressure values (Pi) are below an initial setpoint pressure, or a decrease in said speed if said measured pressure values (Pi) are above said initial setpoint pressure.
  • On the other hand said mathematical function descriptive of a curve of demand includes an opening constant of the consumption point as one of the mentioned coefficients, and the mentioned curve of demand refers to at least one opening constant per consumption point.
  • The method envisages calculating each of said flow rate values of step c) from the corresponding measured pressure value (Pi) and from a characteristic pump curve selected from a plurality of known characteristic pump curves previously recorded in the system (stored for example in a non-volatile, accessible memory), one per rotating speed, relating discharge height with flow rate,.
  • The mentioned calculation of the corresponding flow rate values is based on the scaling laws which establish that the flow rate is proportional to the speed and the pressure is proportional to the square thereof.
  • Therefore, the following actions are performed for calculating the flow rate (Qc) from the actual pressure (P) and speed (v):
    1. 1 - Determining the closest characteristic curves of speed v1< v <v2.
    2. 2 - Calculating the pressures similar to the current one at speeds v1 and v2 (according to scaling laws): P 1 = P * v 1 / v 2
      Figure imgb0001
      P 2 = P * v 2 / v 2
      Figure imgb0002
    3. 3 -Finding the closest points within the curve v 1 : P 1 L < P 1 < P 1 H
      Figure imgb0003
      v 2 : P 2 L < P 2 < P 2 H
      Figure imgb0004
    4. 4 - Reading the flow rate in the four points found from the point matrix:
      • Q1L: flow rate at pressure P1L i speed v1.
      • Q1H: flow rate at pressure P1H i speed v1.
      • Q2L: flow rate at pressure P2L i speed v2.
      • Q2H: flow rate at pressure P2H i speed v2.
    5. 5 - Calculating the flow rates by interpolation (quadratic) Q 1 = Q 1 L 2 + Q 1 H 2 - Q 1 L 2 * P 1 - P 1 L / P 1 H - P 1 L 1 / 2
      Figure imgb0005
      Q 2 = Q 2 L 2 + Q 2 H 2 - Q 2 L 2 * P 2 - P 2 L / P 2 H - P 2 L 1 / 2
      Figure imgb0006
      Qc = Q 1 + v - 1 * Q 2 - Q 1 / v 2 - v 1
      Figure imgb0007
  • For each of the pressure values of step c) (Pi1), (Pi2) (in which an increasing or decreasing trend can be seen), and with the aid of the rotating speeds and the characteristic pump curves, a corresponding flow rate is thus obtained, making obtaining a curve of demand possible by applying the mathematical function expressing the flow rate and pressure relationship.
  • To assure the precision of the calculated values, acquiring successive measurements of the pump suction pressure has also been envisaged, and applying a correction of the successive pressure measurements in said previous point, taking into account the value of the measured suction pressure.
  • According to a preferred aspect of the invention, a proposal is made to use several bundles or sets of characteristic pump curves corresponding to different working conditions of said pump, including at least the temperature of the drive motor of the pump and operating time of the pump recorded in the system (also stored in an accessible memory). More precise and reliable flow rate calculations are thus achieved since they correspond with the operating situation of the pump at all times during its entire operation.
  • The features of the centrifugal pump will thus be input by means of a set of characteristic curves at different speeds and at different temperatures of the pump acquired in a laboratory. The data can be input as a polynomial or as a point matrix. In the latter case linear or quadratic interpolations will be performed between the data to enable knowing any point of the curve.
  • The method comprises performing at least said steps a) to e) for locating two or more of said consumption points of the step d) in a different location.
  • According to the mentioned control method, if after determining said consumption point, or first consumption point, in said step d) a drop in the supply pressure in said common point is detected the method comprises determining that said drop in pressure has been caused by one of the following reasons:
    1. i) because the flow rate of the consumption point has been modified (increase or decrease) adopting a second opening constant; or
    2. ii) because at least one second consumption point has been added, in the latter case fluid being supplied to both consumption points through said common point,
    discriminating one case from another based on detecting one and the same or a different consumption point when obtaining, as discussed, the new curve of demand.
  • According to the method which is being described, in the case of i), an associated resulting curve of demand combining the curves of demand of the same consumption point for first and second opening constants is obtained and used for varying the setpoint pressure of step e)
  • In contrast, if reason ii) occurs in step c) a new curve of demand is determined from the coefficients of at least the previous curve of demand and the difference of the flow rates calculated in the new situation, from the successive readings of the pressure values in said previous point. If there were already two previous curves of demand obtained from previous situations of applying the method, the coefficients of said previously known two curves of demand would be taken into consideration, in addition to the difference in the flow rates calculated in the new situation with respect to the immediate preceding situation.
  • It has been further envisaged that, once said consumption point has been identified, additional tasks for controlling and monitoring said consumption point locally or remotely in a customised manner and by actuating the pump and modifying the supply conditions thereof in a predetermined extension (limited variation range). A user can thus influence the system by setting its performance to achieve a determined comfort and he/she can also manage the water and energy saving of the installation.
  • Lastly, the method further envisages applying a correction to the location of the consumption point determined in step d), said correction comprising the consumption intensity measurement of the pump at all times and using known characteristic power curves of consumption /flow rate of the pump previously stored in the system.
  • In one embodiment, said correction is only applied when the calculated flow rate values are below a predetermined threshold value, i.e., for flow rate values less than 1500 l/h, for example.
  • The invention also provides a piece of control equipment for controlling a multipoint fluid distribution system which provides fluid to a plurality of consumption points requiring different supply pressures, the control system comprising, according to a known structure, the following elements:
    • a pressure sensor arranged for measuring the supply pressure in at least one point of said fluid distribution system;
    • control means in connection with said pressure sensor and with regulation means for regulating the speed of a centrifugal pump of said fluid distribution system, configured for controlling the fluid supply pressure for said plurality of consumption points, actuating on said regulation means, taking said different supply pressures as setpoint pressures for said control, and for varying the values of said setpoint pressures depending on the pressure measured by said pressure sensor.
  • The control equipment according to this invention is provided for implementing the proposed method described above and for such purpose the point of the distribution system where the pressure sensor is arranged is a point (advantageously inside the pump or contiguous thereto) previous to said consumption points through which the fluid directed to at least part of said consumption points flows, and the control system comprises at least one memory where the following are recorded:
    • said known mathematical function descriptive of a curve of demand relating discharge height and flow rate of the pump, and
    • a plurality of characteristic pump curves, one per rotating speed, relating discharge height with flow rate in different working conditions;
  • In turn, said control means include processing means, they have access to the values recorded in said memory and are configured for:
    • ∘ controlling the pressure sensor for carrying out step a) of the method;
    • ∘ controlling said regulation means for regulating the speed of the pump for performing step b) of the method;
    • ∘ performing steps c) and d) of the method by means of said processing means using at least the values measured by the pressure sensor and those recorded in said at least one memory; and
    • ∘ performing step e) of the method by means of said processing means depending on the location determined in step d).
    Brief Description of the Drawings
  • The foregoing and other advantages and features will be better understood from the following detailed description of several embodiments referring to the attached drawings which must be interpreted in an illustrative and non-limiting manner, in which:
    • Figure 1 shows a diagram of flow rate, discharge height, the obtainment of a curve of demand 10 according to the principals of the method proposed by this invention only from acquiring a successive series of supply pressure measurements Pi at different rotating speeds of the centrifugal pump, detecting a variation in pressure (herein a drop), modifying the pump rotating speed to compensate said variation, detecting points Pi1, Pi2 where an inflection or a trend change (in the case depicted, an increase) and calculating the corresponding flows rates using, to that end, a series of characteristic pump curves (11a, 11b,11c, 11d, 11e, 11f), one per rotating speed which are shown as a graph in the figure as explained above. The figure also shows how a consumption point 12 is obtained for the shown situation according to that detailed above.
    • Figure 2 illustrates a diagram of pressure (discharge height)/ flow rate of several curves of demand 13a, 13b, 13c, 13e is response to different requests of the fluid distribution system, three of said curves 13a, 13b, 13c having a common point of origin or height 14 (consumption point) and a fourth curve having a different consumption point 15. In the diagram one of the characteristic curves 11a of a centrifugal pump at a fixed frequency has also been depicted.
    • Figure 3 illustrates obtaining a curve of demand 18 by applying the proposed method when simultaneity situations arise between consumption points of different floors illustrated from corresponding curves of consumption 16, 17.
  • Lastly, Figure 4 is a graph illustrating, in a diagram, flow rate/ time in different characterised consumption points of a dwelling: 19 (sink: 20a hot water, 20b cold water); 21 (wash basin), 22 (shower), 23 (taps), (24) bidet, 25 (WC), observing the disparity of the supply conditions that they require.
  • Detailed Description of the Invention
  • A proposal is made to use a centrifugal pump with a brushless DC type synchronous motor (although it is possible to use an alternating current motor) for the purpose of knowing the speed accurately and preventing the sliding of the motor from affecting the calculations to be made by computational means (for example a microcontroller integrated in a card).
  • The pressure sensor used is a digital transducer calibrated at different temperatures and with a 14 bit analogue/digital converter, for the purpose of obtaining sufficient resolution.
  • The calculations have been made in a type of 32 bit floating point to enable covering very large ranges of numbers, taking into account that a sum of flow rates raised to the fourth magnitude is performed when calculating the height.
  • Tests have been carried out with a centrifugal pump with a check valve in the suction for facilitating precise pressure reading of the installation.
  • In a preferred embodiment, the proposed system is designed for a home pressure system of a single family dwelling and applied in a pump and frequency variator assembly for meeting the needs of such dwelling. However, this concept is completely applicable, and even more appealing economically speaking, if its application is considered in the pressure system of a building with many floors where the differences between the maximum pressure required for the top floor and that required for lower floors are greater.
  • The proposed control system is also applicable to any industrial distribution system with a frequency variator which requires operating at different objective pressures automatically without the need for additional auxiliary elements or a costly installation.
  • System Characterisation
  • Figure 2 shows the characteristic curve 11a of a centrifugal pump at a fixed frequency. This characteristic curve relates the flow rate (Q) and the pressure (H): H Q = a 1 Q 3 + b 1 Q 2 + c 1 Q + d 1 mca
    Figure imgb0008
    Q H = a 2 H 3 + b 2 H 2 + c 2 H + d 2 m 3 / h
    Figure imgb0009
  • Wherein the values of a, b, c and d are pump-dependent coefficients.
  • The influence of the variation of the rotating speed (ω) of the pump in the resulting characteristic curve which are related according to the scaling laws must also be taken into account. n = ω 1 ω 0 actuai maximum 50 Hz Q 1 = a H 1 n 2 3 + b H 1 n 2 2 + c H 1 n 2 + d
    Figure imgb0010
  • Similarly, the curve of demand (defining the consumption point) can be characterised in a similar manner, in which load losses (ΔH) are related with the flowing flow rate (Q) which is formally expressed as the following: Δ H = O + K Q 2
    Figure imgb0011
  • The influence of the point O (geometric origin of the consumption point) and the value of K (opening constant of the consumption point) can be seen in Figure 1.
  • Detection of the origin
  • It is necessary to know the value of O, independently of the value of the opening constant to enable providing the suitable pressure.
  • It is possible to determine the value of the origin 12 (see Figure 1) if the pressure and flow rate values in two points Pi1, Pi2 of the curve of the system are provided, which are achieved by making the pump work at two different and close enough rotating speeds so that it is not noticed in the consumption point.
  • If the pressures (H) are measured and the flow rates are calculated through the relationships defined in the characterisation phase of the system the values of K and consequently O are obtained. K = H 2 - H 1 Q 2 2 - Q 1 2 O = H 1 - K Q 1 2
    Figure imgb0012
  • Once the geometric origin 12 of the consumption point is determined the new setpoint pressure can be calculated taking into account the pressure required by the BTC (building technical code) according to: P PC = O + P CTE
    Figure imgb0013
  • With the control methods of a current constant pressure system, the system is able to work at the optimum pressure required according to the geometric origin 12 of the consumption point.
  • The origin detection method becomes complex when simultaneity situations arise between points of the same or different floors, which requires the definition of a more complex monitoring and control protocol, according to the method explained above and illustrated in Figure 3 for obtaining the curve 18 from curves of demand 16, 17 of two different consumption points.
  • With the possibility of detecting the consumption point 12 even in simultaneity situations, the system provides optimum performance in any possible demand situation.
  • Given that the performance in terms of flow rates required by the BTC are greater than the mean, being able to provide the system with automatic operating modes which allow reducing consumption is interesting. For that purpose, the following is proposed:
    • ∘ Two or more operating modes at reduced pressure providing an added saving at water and energy level
    • ∘ Acceptable comfort reduction in the service
    • ∘ Easy mode activation/deactivation/change
  • In the different saving modes lower pressures which at the same time involve a reduction in electrical and flow rate consumption additional to those offered from the curve of demand obtained by applying the method of this invention are offered.
  • Likewise it is envisaged that the user can apply a correction coefficient to the desired pressure in the consumption point involving a positive or negative increase in said pressure, introducing for such purpose a correcting factor (within of a specified range) which will be taken into account in the future for calculating the subsequent curves of consumption.
  • Consumption point characterisation
  • Characterising a consumption point involves knowing its curve of demand, i.e., the flow rate provided for each pressure value.
  • To that end it is assumed that, according to that described above, the relationship H = O + K Q2 is complied with.
  • As a consequence of the dynamic nature of the electric/hydraulic system, much more information will be obtained if all the pressure and speed readings which can be obtained are used. In other words, instead of attempting a location on a specific curve, all the intermediate points will be taken, thus the variations of pressure are progressive, without gaps.
  • When variations exist, it is important that each pressure reading corresponds with the speed in the same instant. To that end, filtering the readings and correcting the delays so that the points are coherent is necessary. In this sense it is advisable that the changes in pressure and speed occur with the most constant acceleration possible.
  • On the other hand and as indicated above, the set of points can be taken both in ascending as descending direction. Therefore, when the pressure is below the setpoint the points will be taken in an ascending manner (from lower to higher speed and pressure) and when the pressure is above the setpoint they will be taken in a descending manner (from higher to lower speed and pressure).
  • The precision obtained will depend greatly on the number of points used. This depends both on the acceleration (the slower the variations the better) and on the range of variation of the points (the wider the better) having to adopt a compromise that assures comfort.
  • Calculation of the height and opening constant of each consumption point
  • The parameters will be obtained by means of a linear regression between the pressure and the square of the flow rate (Q2), linked by the relationship Q = (a+b* H)2.
    Then, the height will be O=a/b and the opening constant K=b
  • A proposal is made to use the relationship Q2= a+b*H, instead of H= a+b*Q2, because the regression is performed by means of the minimum square method, and in this case it is of interest to minimize the error of flow rate, mainly for low consumption.
  • Therefore: O = Σ H * Σ H * Q 2 - Σ H 2 * Σ Q 2 / n * Σ H * Q 2 - Σ H * Σ Q 2
    Figure imgb0014
    k = n * Σ H * Q 2 - Σ H * Σ Q 2 / n * Σ H 2 - Σ H 2
    Figure imgb0015
  • Detection of condition change of the system or simultaneity
  • The flow rate provided when there is a consumption point is Qp wherein (Qp)2= k*(H-O), wherein k and O have been calculated by means of the mentioned method.
  • If the calculated flow rate is different from that provided (greater or lesser), it means that the consumption points have changed and performing a new regression is necessary, but taking the flow rate variation with respect to that provided (Qc-Qp) as data for the purpose of knowing the contribution of the new consumption point. If any consumption point (lower flow rate) has been closed, this variation will be negative, and the resulting negative k will be indicative of this decrease.
  • Once the new results have been obtained, decision must be made on how the consumption points are modified:
    1. a) If an additional tap has been opened in a flat different from the previous ones, the value of k will be positive and the point O will be different from any previously calculated consumption point. In this case a new consumption point would be added.
    2. b) If the additional tap which has been opened belongs to the same flat with an already operating previous tap, the value of k will be positive and the value of O will be similar to the previous consumption point. In this case the opening constant of said consumption point is modified. Optionally, if the heights are not identical, it is possible to perform a correction by calculating a weighted mean between the previous O and the new one.
    3. c) If a tap is closed, be it partially or completely, the value of k will be negative. In this case the value of the opening constant of the consumption point closest in height is reduced, or the consumption point is eliminated, depending on the case.
  • With reference to Figure 4 illustrating the results of a study wherein different characterised consumption points are shown, it is indicated that taking the control system to a more optimal operation, providing higher savings, researching different aspects in addition to those proposed in the previous phases is feasible.
  • Performing the following is particularly contemplated
    • Specific identification of the consumption point for maximum utilisation of hydraulic and energy resources according to demand.
    • Leakage check
    • Real time monitoring
    • Remote control
    • Communication of the control system with a home automation system.

    Claims (14)

    1. A method for controlling a multipoint fluid distribution system which comprises:
      setting the working conditions of the motor of a centrifugal pump of the distribution system by determining a fluid supply pressure for feeding a plurality of consumption points which may require different supply pressures taken as the pump setpoint pressures, and
      measuring the supply pressure in at least one point of said fluid distribution system and varying the values of said setpoint pressures depending on the measured pressure,
      wherein said point of the distribution system where said pressure measurement is performed is a point previous to said consumption points through which the pumped fluid flows, and wherein the method comprises performing the following steps in sequence:
      a) permanently acquiring a successive series of supply pressure values (Pi) measured in said previous point; and
      b) successively varying the pump rotating speed for compensating said pressure variation in response to a pressure variation detected in said previous point as a result of said measurements of step a);
      the method being characterised in that it further comprises:
      c) detecting that at least two of said pressure values (Pi1), (Pi2), measured in said previous point increases or decreases in response to said variation of the pump rotating speed, and obtaining a curve of demand (10) by calculating the coefficients of a known mathematical function descriptive of said curve of demand relating discharge height and flow rate of the pump, making said coefficient calculations from said measured pressure values (Pi1), (Pi2) and of corresponding calculated flow rate values;
      d) determining a consumption point (12) which is equal to the value of the discharge height obtained when applying a flow rate value equal to zero in said mathematical function descriptive of the curve of demand with calculated coefficients;
      e) adopting a pump rotating speed providing a pump setpoint pressure, depending on said consumption point determined in step d), and
      f) restarting steps b) to e) in the event that another pressure variation is detected in said succession of values measured in step a) indicative of an alteration in the demand.
    2. The method according to claim 1, characterised in that said variation of pump rotating speed of step b) is an increment if the measured pressure values (Pi) are below an initial setpoint pressure, or a decrease if said measured pressure values (Pi) are above said initial setpoint pressure.
    3. The method according to claim 1, characterised in that it comprises calculating each of said flow rate values of step c) from the corresponding measured pressure value (Pi) and from a characteristic pump curve selected from a plurality of known characteristic pump curves (11a, 11b, 11c, 11d, 11e, 11f) previously recorded in the system, one per rotating speed, relating discharge height with flow rate.
    4. The method according to claim 3, characterised in that it comprises using several bundles or sets of characteristic pump curves corresponding to different working conditions of the pump, including at least temperature of the drive motor of the pump and operating time of the pump, registered in the system.
    5. The method according to any one of the preceding claims, characterised in that said mathematical function descriptive of a curve of demand includes an opening constant of the consumption point as one of said coefficients, and said curve of demand refers to at least one opening constant per consumption point.
    6. The method according to any one of the preceding claims, characterised in that it comprises performing at least said steps a) to e) for at least locating two of said consumption points of step d) in a different location.
    7. The method according to any one of the preceding claims, characterised in that it further comprises acquiring successive measurements of the pump suction pressure, and applying a correction of the successive pressure measurements in said previous point, taking into account the value of the measured suction pressure.
    8. The method according to any one of claims 1 to 6, characterised in that if after determining said consumption point (12), or first consumption point, in said step d) a drop in the supply pressure in said common point is detected, the method comprises determining that said drop in pressure has been caused by one of the following reasons:
      i) because the flow rate of the consumption point has been modified adopting a second opening constant; or
      ii) because at least one second consumption point has been added, in the latter case fluid being supplied to both consumption points through said common point,
      discriminating one case from another based on detecting one and the same or a different consumption point in the new curve of demand.
    9. The method according to claim 8, characterised in that in the case of i), an associated resulting curve of demand combining the curves of demand of the same consumption point for first and second opening constants is obtained and used for varying the setpoint pressure of step e).
    10. The method according to claim 8, characterised in that if reason ii) occurs in step c) the new curve of demand is determined from the coefficients of at least the previous curve of demand and the difference of the flow rates calculated in the new situation, from the successive readings of the pressure values in said previous point.
    11. The method according to any one of the preceding claims, characterised in that it comprises, once said consumption point has been identified, performing additional tasks for controlling and monitoring said consumption point locally or remotely in a customised manner and by actuating the pump and modifying the supply conditions thereof in a predetermined extension.
    12. The method according to any one of the preceding claims, characterised in that said previous point of pressure measurement is a point inside the pump or contiguous thereto.
    13. The method according to any one of the preceding claims, characterised in that by further applying a correction to the location determined in step d) said correction comprising the consumption intensity measurement of the pump at all times and using known characteristic power curves of consumption /flow rate of the pump previously stored in the system.
    14. A piece of control equipment for controlling a multipoint fluid distribution system by pumping, wherein the distribution system provides fluid to a plurality of consumption points requiring different supply pressures, and said control equipment comprises:
      - at least one pressure sensor arranged for measuring the supply pressure in at least one point of said fluid distribution system;
      - control means in connection with said at least one pressure sensor and with regulation means for regulating the speed of a pump of said fluid distribution system, and configured for controlling the fluid supply pressure for said plurality of consumption points, actuating on said regulation means, taking said different supply pressures as setpoint pressures for said control, and for varying the values of said setpoint pressures depending on the pressure measured by said at least one pressure sensor
      the system being characterised in that it implements the proposed method according to any one of the preceding claims, in that said point of the distribution system where said pressure sensor is arranged is a point previous to said consumption points through which the fluid directed to at least part of said consumption points flows, and in that:
      - the control equipment comprises at least one memory where the following are recorded:
      - at least said known mathematical function descriptive of a curve of demand (10) relating discharge height and flow rate of the pump, and
      - a plurality of characteristic pump curves, one per rotating speed, relating discharge height with flow rate in different working conditions;
      and in that said control means include processing means, they have access to the values recorded in said memory and are configured for:
      ∘ controlling the pressure sensor for carrying out step a) of the method;
      ∘ controlling said regulation means for regulating the speed of the pump for performing step b) of the method;
      ∘ performing steps c) and d) of the method by means of said processing means using at least the values measured by the pressure sensor and those recorded in said at least one memory; and
      ∘ performing step e) of the method by means of said processing means depending on the location determined in step d).
    EP12382344.5A 2012-09-07 2012-09-07 Method and equipment for controlling a multipoint fluid distribution system Active EP2562424B1 (en)

    Priority Applications (1)

    Application Number Priority Date Filing Date Title
    EP12382344.5A EP2562424B1 (en) 2012-09-07 2012-09-07 Method and equipment for controlling a multipoint fluid distribution system

    Applications Claiming Priority (2)

    Application Number Priority Date Filing Date Title
    ES12382344.5T ES2541584T3 (en) 2012-09-07 2012-09-07 Method and control equipment of a multi-point liquid distribution system
    EP12382344.5A EP2562424B1 (en) 2012-09-07 2012-09-07 Method and equipment for controlling a multipoint fluid distribution system

    Publications (3)

    Publication Number Publication Date
    EP2562424A2 EP2562424A2 (en) 2013-02-27
    EP2562424A3 EP2562424A3 (en) 2013-03-13
    EP2562424B1 true EP2562424B1 (en) 2015-05-27

    Family

    ID=46980870

    Family Applications (1)

    Application Number Title Priority Date Filing Date
    EP12382344.5A Active EP2562424B1 (en) 2012-09-07 2012-09-07 Method and equipment for controlling a multipoint fluid distribution system

    Country Status (2)

    Country Link
    EP (1) EP2562424B1 (en)
    ES (1) ES2541584T3 (en)

    Families Citing this family (2)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    DE102014110911A1 (en) 2014-07-31 2016-02-04 Xylem Ip Management S.À.R.L. Method for operating a liquid delivery system and delivery pump
    DE102014222390A1 (en) * 2014-11-03 2016-05-04 Continental Automotive Gmbh Method for creating a characteristic field of a fluid pump, use of a limited valve, use of a stepped valve and control unit for a fluid delivery system

    Family Cites Families (7)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    JPS6293498A (en) * 1985-10-21 1987-04-28 Hitachi Ltd Operation of speed controlled pump
    DE4243118A1 (en) * 1992-12-21 1994-06-23 Continental Ag Maintaining constant press. in hydraulic system
    US5540555A (en) * 1994-10-04 1996-07-30 Unosource Controls, Inc. Real time remote sensing pressure control system using periodically sampled remote sensors
    DE19831997A1 (en) * 1998-07-16 2000-01-20 Ewald Hennel Method for regulating the pressure of a fluid
    US6464464B2 (en) * 1999-03-24 2002-10-15 Itt Manufacturing Enterprises, Inc. Apparatus and method for controlling a pump system
    AT273533T (en) 2001-08-22 2004-08-15 Vogel Pumpen Method for determining a pump control characteristic
    US7407371B2 (en) 2003-10-29 2008-08-05 Michele Leone Centrifugal multistage pump

    Also Published As

    Publication number Publication date
    ES2541584T3 (en) 2015-07-21
    EP2562424A3 (en) 2013-03-13
    EP2562424A2 (en) 2013-02-27

    Similar Documents

    Publication Publication Date Title
    JP5186530B2 (en) System and method for flow monitoring and control
    US10048706B2 (en) System and method for optimizing use of individual HVAC units in multi-unit chiller-based systems
    US5742500A (en) Pump station control system and method
    US8032235B2 (en) Model predictive control system and method for reduction of steady state error
    US4526513A (en) Method and apparatus for control of pipeline compressors
    US9151516B2 (en) Smart energy controlled water heater
    US8303260B2 (en) Method and apparatus for pump protection without the use of traditional sensors
    CA2443175C (en) Control system for progressing cavity pumps
    US5626287A (en) System and method for controlling a water heater
    EP1662147B1 (en) Control unit for compressor
    US9181953B2 (en) Controlling pumps for improved energy efficiency
    ES2227112T3 (en) Procedure to determine a characteristics of a pump.
    US8180593B2 (en) Determination and control of wellbore fluid level, output flow, and desired pump operating speed, using a control system for a centrifugal pump disposed within the wellbore
    EP2659141B1 (en) Method and apparatus for pump control using varying equivalent system characteristic curve, aka an adaptive control curve
    JP2001152875A (en) Method and system for compensating measurement error
    CN104871107B (en) For optimizing the automatic learning control system and method that can consume input variable
    US20070185661A1 (en) Measurement method and arrangement
    US10048701B2 (en) Dynamic linear control methods and apparatus for variable speed pump control
    CN103809437B (en) A motor constant air volume control method
    CA2841412C (en) Estimating fluid levels in a progressing cavity pump system
    US20080300727A1 (en) Method of calculating pump flow rates and an automated pump control system
    DE602004004496T2 (en) Energy consumption in an electric drive
    EP1645928B1 (en) Method of determining the supply state of a heating surface and supply state regulator
    US9810438B2 (en) Controlled hydronic distribution system
    Viholainen et al. Energy-efficient control strategy for variable speed-driven parallel pumping systems

    Legal Events

    Date Code Title Description
    AX Request for extension of the european patent to:

    Extension state: BA ME

    AK Designated contracting states

    Kind code of ref document: A2

    Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

    RIC1 Information provided on ipc code assigned before grant

    Ipc: F04D 15/00 20060101AFI20130205BHEP

    AX Request for extension of the european patent to:

    Extension state: BA ME

    AK Designated contracting states

    Kind code of ref document: A3

    Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

    17P Request for examination filed

    Effective date: 20130418

    INTG Intention to grant announced

    Effective date: 20141202

    AK Designated contracting states

    Kind code of ref document: B1

    Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

    REG Reference to a national code

    Ref country code: GB

    Ref legal event code: FG4D

    REG Reference to a national code

    Ref country code: CH

    Ref legal event code: EP

    REG Reference to a national code

    Ref country code: AT

    Ref legal event code: REF

    Ref document number: 729013

    Country of ref document: AT

    Kind code of ref document: T

    Effective date: 20150615

    REG Reference to a national code

    Ref country code: IE

    Ref legal event code: FG4D

    REG Reference to a national code

    Ref country code: DE

    Ref legal event code: R096

    Ref document number: 602012007567

    Country of ref document: DE

    REG Reference to a national code

    Ref country code: ES

    Ref legal event code: FG2A

    Ref document number: 2541584

    Country of ref document: ES

    Kind code of ref document: T3

    Effective date: 20150721

    REG Reference to a national code

    Ref country code: AT

    Ref legal event code: MK05

    Ref document number: 729013

    Country of ref document: AT

    Kind code of ref document: T

    Effective date: 20150527

    REG Reference to a national code

    Ref country code: LT

    Ref legal event code: MG4D

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: HR

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: FI

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: NO

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150827

    Ref country code: LT

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: PT

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150928

    REG Reference to a national code

    Ref country code: NL

    Ref legal event code: MP

    Effective date: 20150527

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: BG

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150827

    Ref country code: GR

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150828

    Ref country code: LV

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: IS

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150927

    Ref country code: RS

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: AT

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: EE

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: DK

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: PL

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: CZ

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: SK

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: RO

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20150527

    REG Reference to a national code

    Ref country code: DE

    Ref legal event code: R097

    Ref document number: 602012007567

    Country of ref document: DE

    REG Reference to a national code

    Ref country code: CH

    Ref legal event code: PL

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: LU

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150907

    Ref country code: MC

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    26N No opposition filed

    Effective date: 20160301

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: SI

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    REG Reference to a national code

    Ref country code: IE

    Ref legal event code: MM4A

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: IE

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20150907

    Ref country code: LI

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20150930

    Ref country code: CH

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20150930

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: BE

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: PLFP

    Year of fee payment: 5

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: MT

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: SM

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: HU

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

    Effective date: 20120907

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: CY

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: SE

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    Ref country code: NL

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: TR

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: PLFP

    Year of fee payment: 6

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: MK

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: PLFP

    Year of fee payment: 7

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: AL

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20150527

    PGFP Annual fee paid to national office [announced from national office to epo]

    Ref country code: GB

    Payment date: 20180907

    Year of fee payment: 7

    PGFP Annual fee paid to national office [announced from national office to epo]

    Ref country code: DE

    Payment date: 20180930

    Year of fee payment: 7

    PGFP Annual fee paid to national office [announced from national office to epo]

    Ref country code: ES

    Payment date: 20181001

    Year of fee payment: 7

    PGFP Annual fee paid to national office [announced from national office to epo]

    Ref country code: FR

    Payment date: 20190930

    Year of fee payment: 8

    Ref country code: IT

    Payment date: 20190911

    Year of fee payment: 8