RU2680474C2 - Device (options) and method for pump differential pressure and flow monitoring - Google Patents

Abstract

FIELD: pumps.SUBSTANCE: group of inventions relates to the field of sensorless control of a pump, in particular a pump or pumps for domestic and industrial systems of heating or cooling water. In the method, the device for monitoring pressure drop and flow rate in a pump comprises a processing or processor signal, configured to receive signals, containing information about motor readout values of power and speed, information about the equations of the characteristics of the pump and the system and the empirical power equations, constructed as a polynomial best-fit function in accordance with the laws of affinity for pumps based on the pump curve provided by the pump manufacturer, and with the possibility of determining corresponding signaling containing information about a pump or system pressure and a flow rate at the motor readout values of power and speed, based upon the signaling received.EFFECT: inventions are aimed at improving pump control accuracy without the need for instrument calibration.16 cl, 6 dwg

Description

RELATED APPLICATIONS

This application claims priority on provisional application No. 61 / 976,749 for a US patent (file No. 911-019.014-1 // F-B & G-X0012US01), filed April 8, 2014, under the name "Best Approach Sensorless Conversion Tool for Control differential pressure and flow rate in the pump ", which is incorporated into the text of this application by reference.

This application also relates to technologies developed by at least one of the inventors of the invention and disclosed in the following applications:

1) application No. 12 / 982,286 for a US patent (case No. 911-019.001-1 // F-B & G-1001), filed on December 30, 2010 under the name "Method and device for controlling a pump using the characteristic curve of the corresponding adjustable system, also known as the adaptive control curve ", according to which on April 15, 2014 issued US patent No. 8,700,221;

2) application No. 13/717,086 for a US patent (case No. 911-019.004-2 // F-B & G-X0001), filed December 17, 2012 under the name "Dynamic linear control methods and device for controlling a variable-speed pump", in which claims priority on provisional application No. 61 / 576,737 for a US patent filed December 16, 2011, which is currently withdrawn;

3) application No. 14/091,795 for a US patent (case No. 911-019.009-2 // F-B & G-X0005), filed November 27, 2013 under the title "Method and device for three-dimensional sensorless conversion", which claims priority for provisional application No. 61/771375 for a US patent filed March 1, 2013 and is currently withdrawn;

4) application No. 14 / 187,817 for a US patent (case No. 911-019.010-2 // F-B & G-X0008), filed February 24, 2014 under the name "Mixed theoretical and discrete sensorless transducer for controlling differential pressure and flow rate in a pump" , which claims priority for provisional application No. 61 / 803,258 for a US patent filed March 19, 2013 and is currently withdrawn;

5) U.S. Patent Application No. 14 / 339,594 (Case No. 911-019.012-2 // F-B & G-X0010US01), filed July 24, 2014, entitled "Best Approach and Similarity. Sensorless Transmitter for Monitoring Differential Pressure and Flow in a Pump ", which claims the priority of provisional application No. 61 / 976,749 for a US patent (case No. 911-019.012-1 // F-B & G-X0010US01), filed April 8, 2014; and

6) provisional application No. 62 / 007,474 for a US patent (file No. 911-019.015-1 // F-B & G-X0013), filed June 4, 2014 under the title "System and device for adaptive flow control - operational control system with minimum energy for injection versus sensorless use. ”

All of the above applications are assigned to the patent holder of this application and incorporated into it by reference.

The present invention is based on the technologies disclosed in the above applications.

BACKGROUND

1. Field of invention

The present invention relates to a method for controlling the operation of a pump; in particular, the present invention relates to a method and apparatus for controlling and / or monitoring the operation of a pump, for example, pumps for domestic and industrial heating or cooling water systems.

2. A brief description of the prior art

Introduction

The technology of sensorless control and monitoring of the operation of a liquid pumping system is known from the prior art, for example, a three-dimensional discrete method and a mixed theoretical three-dimensional discrete method of sensorless conversion, described in the applications mentioned above under numbers 3-5. The pressure and flow rate in the system can be determined directly from a pair of read engine values with a conversion error of about 5-15% by means of a three-dimensional discrete sensorless transducer, for example, based on pump calibration data, as indicated in application number 4. On the other hand, the sensorless transducer for the implementation of mixed theoretical and discrete transforms described in the application under the number 3, produces a conversion error of about 10-20% without the need for calibration of instruments, p and it is still necessary to obtain data on the power distribution system, taking into account the engine speed and the coefficient for converting said coefficient system for controlled fluid system.

Sensorless calibration of pump data, including instrumentation and data acquisition, is an interesting topic for discussion, and cannot be easily implemented due to the lack of pressure and flow sensors for most pump applications. In fact, collecting calibration data for a sensorless system for a pump and engine can be quite lengthy and tedious, even in the conditions of production assembly lines, not to mention the use of expensive instruments to obtain data and installations for testing liquid pump systems. Thus, the inventors who have submitted the present application recognize and take into account that a sensorless tool or method that eliminates or reduces the need for data calibration can be more beneficial for most sensorless pumping systems.

For a dynamic fluid system, the flow rate of which is controlled by valves or control devices, the coefficient of performance of the equivalent fluid system is an unknown variable, which essentially depends on the open position of the valves, as well as on the dynamic friction loss in the system. In such a controlled fluid system, pump efficiency is a variable variable due to a delay in the motor speed under a variable fluid load, and also due to certain effects of heat consumption due to mechanical friction in the pump, in particular at low speed, when the system is almost shut down. Thus, the inventors of this application also recognize and take into account that it is rather difficult to formulate any theoretical expressions for creating a sensorless pump transducer configured to determine the pressure and flow values in the system directly on the basis of the read motor values, such as power, current , torque, speed, etc.

SUMMARY OF THE INVENTION

In General, according to the claimed invention, a new and unique means or method of sensorless conversion according to the best approximation method for obtaining pressure and flow values in a pump or system based on a pair of read values of power and engine speed, for example, using the equations of characteristics of the pump and system and empirical power equation. The equation for the characteristics of the pump and the empirical equation of power can be expressed as a polynomial of best approximation in accordance with the similarity laws for pumps in explicit or transformed form, for example, based on the curve of pump characteristics provided by pump manufacturers. Thus, the values of pressure and flow in the system at the equilibrium point of pressure in the pump and the system at steady state operation can be expressed in the form of equations of characteristics of the pump and system, as well as the empirical power equation. The indicated sensorless device and method described in this application may be advantageous for most practical applications of sensorless control and monitoring of liquid pumps, providing a sufficiently high accuracy without the need to calibrate devices.

This application proposes a method representing a further development of the above technologies and based on them.

OPTIONS FOR PERFORMANCE

In accordance with some variants of execution, the invention may include or be a device containing a processor or processor module for signal processing, configured to perform at least the following functions:

receiving signals containing information about the read values of the power and speed of the engine, as well as the equations of characteristics of the pump and system and empirical equations of power, expressed as a polynomial of best approximation in accordance with the laws of similarity for pumps based on the curve of the pump characteristics provided by the pump manufacturer, and

determining appropriate signals containing information about the pressure and flow rate in the pump or system, taking into account the read values of the power and speed of the engine contained in the received signals.

During operation, the processor or processor module of the signal processing can be configured to determine the differential pressure and flow rate in the pump at the pressure equilibrium point in the pump or system with steady-state engine operation.

In operation, said processor or processor module 10a of the signal processing can also be configured to receive corresponding signals containing information about the pressure and flow rate in the pump or system, including to control the pressure drop and flow rate in the pump. These appropriate signals can be used to control the liquid pump system.

Embodiments may also be proposed in which said device comprises or is a liquid pumping system comprising, for example, said processor or processor for processing signals.

The received signals can be determined and obtained by means of appropriate sensors, configured to measure the read values of power and engine speed.

The received signals can be stored and obtained from the corresponding memory modules, which, for example, may contain equations of pump and system characteristics and empirical power equations expressed as a best approximation polynomial in accordance with similarity laws for pumps based on the pump curve provided pump manufacturer.

By way of example, said processor or processor module for signal processing may comprise or comprise at least one processor and at least one memory device comprising computer program code, said at least one memory device and computer program code having at least at least one processor is configured to provide at least the following functions of said processor or processor module for processing signals: receiving signals ( see, e.g., signals associated with them) and the definition of the controlled pressure. The specified processor or processor module signal processing may contain appropriate computer program code for implementing the necessary algorithms for signal processing and / or functionality as described in this application.

The proposed device may contain or be a pump control device or controller, including in the form of a PID (proportional-integral-differential) controller containing the specified processor or processor module for signal processing, for example, made, including, with the possibility of differential control pressure and flow in the pump.

In accordance with some embodiments, the invention can be implemented as a method comprising the following steps: signals containing information about the read values of the power and speed of the engine, as well as the equation of characteristics of the pump and system and empirical equations are received by a processor or processor module for signal processing powers, which are expressed as a polynomial of best approximation in accordance with the laws of similarity for pumps based on the curve of pumping nature Istik provided by the pump manufacturer; by means of the indicated processor or processor module of the signal processing, the corresponding signals are determined containing information about the pressure and flow rate in the pump or system taking into account the read values of the power and speed of the engine, which were contained in the received signals.

The specified method may also contain at least one of these features, including may include the stage at which by means of the specified processor or processor module of the signal processing, the corresponding signals are supplied containing information about the pressure and flow rate in the pump or system, which, for example , can be used to control a liquid pumping system.

The present invention can also be performed, for example, in the form of a computer program product containing a computer-readable medium with computer executable code embedded in this medium to implement this method, for example, by means of a signal processing device that is part of such a controller for a pump. For example, this computer program product can be made in the form of a compact disk, floppy disk, flash drive, memory card, as well as other type or type of drives configured to store the corresponding computer executable code on a computer-readable medium, which is known on present or will be developed in the future.

In conclusion, it should be noted that according to the embodiments described in this application, a means or method of sensorless conversion according to the best approximation method for determining the pressure and flow rate in a pump or system taking into account a pair of read values, namely, engine power and speed, for example, based on equations pump and system characteristics and empirical power equations. The equation of characteristics of the pump and the empirical equation of power can be expressed as a polynomial of best approximation in accordance with the similarity laws for pumps obtained on the basis of the curve of pump characteristics provided by pump manufacturers, which, for example, can be stored in the appropriate memory module and processed. The values of the pressure and flow drops in the pump can be determined at the equilibrium point of pressure in the pump and the system under steady state engine conditions, respectively. The sensorless conversion tool or method described herein for a pump can be easily implemented in most of the possible practical applications for controlling and monitoring liquid injection, while ensuring sufficient accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings contain the following figures, which are not necessarily to scale.

FIG. 1 schematically depicts a liquid sensorless pumping control system known from the prior art, in which, for example, the present invention can be implemented in accordance with one embodiment.

FIG. 2 depicts a sensorless conversion circuit for obtaining pressure and flow in a pump based on recorded power and speed values.

FIG. 3 depicts a graph of pressure (Ft) versus flow (GPM), which shows the curves of the characteristics of the pump, system and power, as well as the pressure equilibrium point at steady state operation in accordance with the implementation of some embodiments of the invention;

системы для расхода (GPM), на котором проиллюстрированы мощность двигателя и системные характеристики в соответствии с осуществлением некоторых вариантов выполнения предлагаемого изобретения.FIG. 4 shows a graph of power (in hp) versus performance

systems for flow (GPM), which illustrates engine power and system characteristics in accordance with the implementation of some embodiments of the invention.

FIG. 5 is a graph of pressure (Ft) versus flow (GPM) showing the pressure drop across the pump versus the flow in the system, determined by a sensorless transmitter (shown by solid lines) and based on data measured or recorded by sensors (shown symbols (e.g. rhombuses, triangles, stars, plus and minus signs, squares and crosses)) at various speeds, including at 24 Hz, 30 Hz, 36 Hz, 42 Hz, 48 Hz, 54 Hz and 60 Hz.

FIG. 6 depicts a block diagram of a device, for example, comprising a processor or processor module for processing signals in accordance with some embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a liquid sensorless pump control system comprising a centrifugal pump connected to a piping system with a flow and a controller, in which, for example, the invention may be implemented. FIG. 2 schematically depicts a sensorless conversion of the differential pressure and flow in a pump in accordance with the coefficient of characteristics of an equivalent fluid system that changes at the pump outlet, as well as engine power and speed at the other end of the motor drive. FIG. 3 schematically shows the curves of the characteristics of the pump, system and power and the corresponding equilibrium point of pressure in the pump and the system at steady state operation for a closed-loop system in which a stable suction pressure is ensured.

соответственно. Указанные законы подобия для насосов представляют собой уравнения для расхода в насосе, перепада давления и мощности двигателя, а именно Q/Q_max=n/n_max, Р/P_max=(n/n_max)² и w/w_max=(n/n_max)³, соответственно.In the case of a system with a closed circuit and a stable suction pressure, the flow rate and pressure in the system at a certain engine speed and system position can be determined at the equilibrium point of pressure in the pump and the system at a steady state operation, which is located at the intersection of the curves of the characteristics of the pump and the system, schematically depicted in FIG. 3. In this case, the characteristic curve of the pump for a point in time, which illustrates the dependence of the differential pressure P in the pump on the flow rate Q and the speed n of the engine, can be approximately represented as a polynomial P = ƒ (Q, n) based on the curve of the characteristics of the pump at maximum speed n _{max of the} engine and in accordance with the law of similarity for pumps. Thus, the flow rate in the system can be expressed in terms of the differential pressure function in the pump P = ƒ (Q, n), as well as through the flow equation in the system

respectively. The indicated similarity laws for pumps are equations for flow in the pump, pressure drop and engine power, namely Q / Q _max = n / n _max , P / P _max = (n / n _max ) ² and w / w _max = ( n / n _max ) ³ , respectively.

Following the above approach, for example, using the curve function of the pumping characteristics of the second order, converted by the best approximation method, and the flow equation in the system, for example, the flow in the system can be expressed as the following Equation (1):

where C _ν is the coefficient of the system, a, b and c are the coefficients of the function curve of the characteristics of the second-order pump, converted by the best approximation method, at a maximum speed n _{max of the} engine. The function used in this case for the pressure drop in the pump P = ƒ (Q, n) can be expressed as Equation (2):

It should be noted that other equations of the flow rate in the system and the pressure difference in the pump can be obtained, while other approximating or interpolating approaches can be chosen for constructing the curve, for example, a third-order polynomial can be used instead of the indicated expressions for approximation or interpolation.

To determine the flow rate and pressure in the system at a pressure equilibrium point under steady-state operation, based on a given pair of values of engine power and speed, according to equations (1) and (2), as a rule, the corresponding coefficient of the dynamic system should be known first. However, for a controlled fluid system in which the flow rate is controlled by valves or other flow controllers, there is no simple theoretical solution in the form of a formula. As described in this application, the ratio of empirical power values to system characteristics obtained on the basis of the power curve at the maximum engine speed n _max and using the similarity law, which is schematically illustrated in FIG. 4. As shown in the drawing, first, by the method of approximation or interpolation, a graph of the engine power function at maximum speed can be constructed taking into account the system coefficient. Then, in accordance with the laws of similarity for pumps, engine power at a given engine speed can be determined, for example, as w = (C _ν , n).

Following, in particular, the above approach, and using the second-order power function by the best approximation method, the coefficient C _{ν of the} system can be precisely expressed in the form of equation (3):

системы. При любом текущем значении скорости функция мощности двигателя w=w(C_ν, n)может быть выражена в виде Уравнения (4):where w is the engine power at speed n; A, B and C are the coefficients of the second-order engine power function according to the best approximation method at maximum engine speed, taking into account the normalized coefficient

system. At any current speed value, the engine power function w = w (C _ν , n) can be expressed as Equation (4):

In the event that an accuracy requirement can be made for a region of small speed values, and the system is in a practically disconnected state, using the similarity law to represent the power of the pumps may not be sufficient to ensure an accurate representation of the dependence of motor power and speed for the shear displacement of the engine speed values in this value range. A slightly increased value of power in the region of small values of speed as a result leads to a slightly increased value of the system coefficient from the inverse power dependence according to Equation (3), as well as to a slightly larger flow rate according to Equation (1), respectively. In this case, it may be necessary to transform the similarity law for engine power and speed, while Equation (4) can be modified as Equation (5):

where ƒ * (n) is the transformed similarity law expressed in the form of an approximating polynomial of the third order, namely, in the form of Equation (6):

where A ', B', C 'and D' are the coefficients of the third-order function of best approximation for power values normalized at maximum speed taking into account the normalized engine speed n / n _max . Unlike the similarity law for pump power w / w _max = (n / n _max ) ³ , the converted similarity law is a third-order approximating polynomial showing the dependence of power and speed obtained by approximating or interpolating a set of power values measured taking into account the set speed setpoints for any state of the system. Since the normalized power distribution ƒ * (n) is approximately the same for any state of the system, the state of the system can be any from disconnected to fully turned on. Similarly, as an additional example, it should be noted that Equations 3-6 can be represented in the form of any other expressions, while, accordingly, other types of approximate or interpolation methods for constructing the curve can be used.

Thus, the flow rate and pressure in the system at the equilibrium point of pressure in the pump and the system at engine speed in accordance with the established operating mode and the corresponding power consumption can be determined by Equations (1) and (2), while from Equations (3) and (4) or (5), respectively, the coefficient C _{ν of the} system can be obtained, which in the present description is called the sensorless transducer by the best approximation method. Thanks to the use of the indicated sensorless transducer by the best approximation method, it is possible to collect pressure and flow values in the pump system and compare them with data measured using sensors. The results illustrated in FIG. 5, demonstrate quite satisfactory accuracy, mainly with an error of about 5-10% in all ranges of speed values from 30 to 60 Hz in normal operation of the liquid zone of the pump and with an error of about 10-20% in the zone of low speed values and when the system is almost disconnected.

The best-approximation sensorless transducer described in this description can be used in most applications to control and control liquid injection, since this transducer is obtained from the equations for pump characteristics and power, as well as from the similarity law and is transformed using the best-approximation polynomial taking into account pump data provided by pump manufacturers. The specified Converter can be quite easily applied, while ensuring sufficient accuracy. However, the most important thing is that its use will help to eliminate the need for tedious and lengthy calibration of devices, since data or curves are provided by manufacturers and are available.

FIG. 6:

As an example in FIG. 6 shows a device 10 made in accordance with some embodiments of the invention, which, for example, may include a processor or processor module 10a signal processing, configured to perform at least the following functions:

receiving signals containing information about the read values of the power and speed of the engine, as well as the equations of the characteristics of the pump and system and empirical equations of power obtained using the best approximation polynomial and similarity laws for pumps based on the pump characteristics curve provided by the pump manufacturer,

determining the appropriate signals containing information about the pressure and flow rate in the pump or system, taking into account the read values of power and engine speed contained in the received signals.

The specified processor or processor module for signal processing can be configured to determine the pressure drop and flow rate in the pump at the pressure equilibrium point in the pump or system at a steady state engine operation during operation.

The specified processor or processor module 10A signal processing can also be configured to supply the appropriate signals containing information about the pressure and flow rate in the pump or system, including for monitoring the differential pressure and flow rate in the pump. Appropriate signals can be used to control the liquid pump system.

It will be obvious and understandable to a person skilled in the art that the invention can be implemented using equations of pump and system characteristics and empirical equations of power, for example, those described in this application, as well as using other types or types of equations of pump characteristics and systems and empirical equations of power that are currently known or will be obtained subsequently in the future.

It will be obvious and understandable to a person skilled in the art that the present invention can be carried out using pumping characteristics curves provided by pump manufacturers, for example, those described in this application and currently known in the art. However, other embodiments may be carried out within the scope of the invention, in which other types or types of pump characteristic curves provided by pump manufacturers for those pumps that will be developed in the future will be used.

For example, it should be noted that the functionality of the device 10 can be implemented using hardware, software, firmware, or a combination thereof. In the case of typical use of the software, the device 10 may comprise at least one microprocessor architecture, comprising, for example, at least one processor or microprocessor of the signal processing, which is an element 10a. A person skilled in the art will be able to specify a program for such a device based on a microcontroller or microprocessor to implement the functionality described in this application without further experimentation. For example, a processor or processor module 10a of the signal processing can be performed, for example, by a person skilled in the art with the possibility (without carrying out additional experiments) of receiving signals containing information about the read values of power and speed of the engine, as well as information about the equations of characteristics of the pump and system and empirical power equations transformed using the best approximation polynomial and similarity laws for pumps, based on the curve of pumping characteristics provided by oizvoditelem this pump, in accordance with the method described herein. For example, information about the read values of engine power and speed can be contained in recorded signals received, processed, and / or stored, for example, in the corresponding memory module, which is part of the microprocessor architecture. Similarly, for example, information about the pump and system characteristic equations and empirical power equations converted using the best approximation polynomial and similarity laws for pumps, taking into account the pump curve provided by the manufacturer of this pump, can be obtained, processed and / or stored in the appropriate a storage module that is part of the microprocessor architecture specified.

In addition, the processor or processor module for signal processing 10a can be performed, for example, by a person skilled in the art with the possibility of determining without additional experiments the corresponding signals containing information about the pressure and flow rate in the pump or system based on the read values of power and speed engine, based on the received signals in accordance with that specified in this application.

The scope of the invention is not limited to any particular embodiment using technology that is known today or will be developed subsequently in the future. The scope of the present invention also includes the implementation of the functional purpose of the processors 10a, made in the form of a stand-alone processor or processor module, a separate processor or processor modules, or in any combination thereof.

The device 10 may also contain, for example, other chips or components 10b of the signal processing processor, including a random access memory device or a memory device (RAM) and / or read-only memory device (ROM), input / output and control devices, data buses and address buses connecting the listed components, and / or at least one input processor and at least one output processor.

Various features that ensure novelty

The invention may comprise or constitute at least one of the following embodiments.

For example, in accordance with some embodiments, the present invention can be implemented or implemented in the form of a sensorless sensor method or method according to the best approximation method for determining the pressure drop and flow rate in a pump, which, for example, may include a sensorless sensor for a pump, configured to determination of the pressure drop in the pump and flow rate in a dynamic system, taking into account the read signals of speed and engine power based on the equations of nature curves the source of the pump and the system and empirical power equations expressed as follows:

P = ƒ (Q, n), P = (Q / C _ν ) ² and W = w (C _ν , n) as, for example, schematically illustrated in FIG. 3.

In accordance with some embodiments, the present invention can be practiced by using one preferred embodiment of the aforementioned means or sensorless best-fit method for differential pressure and flow in a pump, which, for example, may include an expression for determining a differential pressure in a pump or pressure in the system and flow rate at the equilibrium point for the pressure drop in the pump and the pressure in the system, which is at the intersection schematically and siderations curves pump characteristics and the system.

In accordance with some embodiments, the present invention can be carried out using the pump curve equations in the aforementioned tool or the best-fit sensorless conversion method, which, for example, may include pump curve models obtained based on pump characteristic equations taking into account a certain engine speed and flow rate in the system. The indicated models of the curves of the pump characteristics can be approximated using the function P = ƒ (Q, n) based on the characteristic curve of the liquid pump at maximum speed (or the curve of the characteristics of the pump) and the similarity law for pumps. To ensure a sufficiently good representation with high accuracy, the best approximation method can be used to obtain a function for the curve of pumping characteristics P = ƒ (Q, n). For example, to represent the curve of pumping characteristics at speed n, the following second-order best approximation polynomial can be used:

However, if possible, a higher-order polynomial can be used for a pump curve with a somewhat complicated shape to provide a better presentation. In the case of alternative use of other approximation or interpolation methods, some other formulas can be used to construct the curve. Methods for approximating or interpolating a curve are known in the art, and the scope of legal protection of the invention is not limited to any particular type or type of the above approaches that are currently known or will be developed in the future.

или ряд альтернативных выражений или приближений для представления кривой характеристик системы.In accordance with some embodiments, the present invention can be carried out using in the above tool or method a sensorless transformation according to the best approximation of the equation of the curve of the characteristics of the equivalent liquid system, which, for example, may contain a flow equation of the form

or a series of alternative expressions or approximations to represent a curve of system characteristics.

In accordance with some embodiments, the present invention can be carried out using the sensorless method in the aforementioned tool or method according to the method of best approximation of the pressure equilibrium point at steady state, which is at the intersection of the functions of the pump and system curves, as shown in FIG. 3. The values of the pressure in the system or the differential pressure and flow in the pump can be determined at the pressure equilibrium point based on a pair of read values for the engine, for example, speed and power, in the form of output values obtained by the sensorless conversion method. For example, to approximate a second-order curve for pumping characteristics by the best approximation method, the above equations (1) and (2), presented in the following form:

and

can be used as formulas to determine the flow rate and pressure in the system for use in a sensorless transducer, provided that a pair of values is known, namely, the speed and engine power, respectively. However, if necessary, the equations for converting the pressure and flow rate in the system can be expressed in a different form in accordance with the approach using the pressure equilibrium point in the steady state, approximating or interpolating functions of a higher order or some other types of functions can be used .

In accordance with some embodiments, the present invention can be carried out using the empirical power function best approximation method in the above-described means or method to determine the coefficient of performance of an equivalent system based on engine power and speed, said empirical function being, for example , an empirical power function of the form w (C _ν , n) taking into account the values of the engine speed and flow rate in the system. The indicated models of the power curve can be approximately expressed using the function w (C _ν , n) based on the power curve at maximum speed and in full accordance with the curve of the characteristics of the pump and the law of similarity. Similarly, for a sufficiently good representation of the power curve function w (C _ν , n) with high accuracy, the best approximation method can be applied. For example, a second-order best approximation polynomial according to the following Equation (4)

характеристик эквивалентной системы, значения которых получены на основе соответствующей кривой мощности, соответствующей кривой характеристик насоса при максимальной скорости, которая схематично проиллюстрирована на Фиг. 4. При необходимости для обеспечения лучшего представления функций кривой мощности может быть использован многочлен более высокого порядка или другие виды выражений.can be used to represent the power curve function taking into account the speed n of the engine and the normalized coefficient

characteristics of the equivalent system, the values of which are obtained on the basis of the corresponding power curve corresponding to the curve of the characteristics of the pump at maximum speed, which is schematically illustrated in FIG. 4. If necessary, a higher order polynomial or other types of expressions can be used to provide a better representation of the power curve functions.

In accordance with some embodiments, the present invention can be implemented using one preferred embodiment of an empirical power function in a sensorless conversion method using the best approximation method to determine the pressure drop and flow rate in the pump, which, for example, may contain the best approximation polynomial according to Equation (4 ):

and also the transformed power similarity law мощ * (n), expressed as a third-order polynomial in accordance with Equation (6):

The transformed power similarity law ƒ * (n) was obtained by approximating a set of power values normalized taking into account the corresponding maximum speed value from a set of known speed values at a certain state of the system, and can be used to compensate for changes in power values in the region of small speed values corresponding to the disabled system status.

In accordance with some embodiments, the present invention can be carried out using a sensorless conversion means or method according to the best approximation method of converting the coefficient of characteristics of the system, which, for example, can contain all kinds of expressions, namely, a solution in the form of a formula or a solution using some discrete numerical methods. For example, Equation (3) of the following form:

can be expressed as a formula derived to obtain an expression for determining the coefficient of characteristics of an equivalent system from equation (4) for an empirical power function.

In accordance with some embodiments, the invention may be practiced by using a best-approximation sensorless means or method in a liquid pumping system, which, for example, can be any closed-loop or open-loop liquid pumping system, including a primary pumping system system, secondary pumping system, water circulation system and pressure boosting system. These systems may consist of one or several sections.

In accordance with some embodiments, the present invention can be implemented using data according to the curves of pumping characteristics and power curves at maximum engine speed and be a means or method of sensorless conversion according to the best approximation method, in which, for example, data according to the curves can be used pump characteristics and power curves provided by pump manufacturers, or some values of pump characteristics measured at max. maximum engine speed during operation. Data according to the engine power curve can also be replaced by any possible electrical or mechanical signals read on the engine, for example, such as current or torque values of the engine, etc.

In accordance with some embodiments, the present invention can be carried out using, in a means or method, a sensorless conversion according to the best approximation method of liquid signals, which, for example, may contain, differential pressure values in the pump, pressure values in the system or on some of its plot, flow rate values in the system or on its plot, etc.

In accordance with some variants of execution, the present invention can be implemented using wire communication technologies and transmission of control signals, which, for example, can contain all the standard recording and transmitting means currently in use. Preferred, optimal and advantageous is the use of technology for transmitting signals through wireless sensors.

In accordance with some embodiments, the present invention can be carried out using the above pumps for liquid pumping systems, which, for example, can be a single pump, a circulation pump, a group of parallel connected pumps or circulation pumps, a group of series-connected pumps or circulation pumps, or their combinations.

In accordance with some embodiments, the present invention may be practiced using flow control systems, which, for example, may include manual or automatic valves, manual or automatic circular pumps, or combinations thereof.

The above options for implementation are given as examples, while the scope of legal protection of the invention also includes other types or types of implementation corresponding to those described in this application and not changing the essence of the invention.

Scope of legal protection of an invention

It should be understood that, unless otherwise indicated, any feature, characteristic, alternative, or modification of those specified in relation to a particular embodiment described herein may also be applied, used, or included in any other described embodiment. In addition, the drawings provided in this application are not to scale.

Despite the fact that the invention is described by the example of a centrifugal pump, the scope of legal protection of the invention includes the possibility of its implementation in relation to other types or types of pumps that are currently known or will be developed in the future.

Despite the fact that the invention is described and illustrated by the example of illustrative embodiments, the above, as well as other additions and exceptions may be made in these embodiments within the essence and scope of legal protection of the invention.

Claims (38)

1. A device for monitoring the differential pressure and flow rate in the pump, containing: a processor or processor module for signal processing, configured to implement at least the following: receiving signals containing information about the read values of the power and speed of the engine, as well as information about the equations of characteristics of the pump and system and empirical equations of power, which are expressed as a polynomial of best approximation in accordance with similarity laws for pumps based on the curve of pump characteristics provided by the pump manufacturer , and determining the appropriate signals containing information about the pressure and flow rate in the pump or system, taking into account the indicated read values of the power and speed of the engine contained in the specified received signals. 2. The device according to claim 1, wherein said processor or processor module for signal processing is configured to determine the pressure drop and flow rate in the pump at a pressure equilibrium point in the specified pump or system with steady state engine operation. 3. The device according to claim 1, wherein said processor or processor module for signal processing is configured to supply said corresponding signals containing information about pressure and flow rate in the pump or system, including for controlling pressure drop and flow rate in the pump. 4. The device according to claim 3, wherein said respective signals comprise information used to control the liquid pumping system. 5. A device for monitoring the differential pressure and flow rate in the pump, comprising a processor or processor module for signal processing, configured to implement at least the following: receiving signals containing information about the read values of the power and speed of the engine, as well as information about the equations of characteristics of the pump and system and empirical equations of power, which are expressed as a polynomial of best approximation in accordance with similarity laws for pumps based on the curve of pump characteristics provided by the pump manufacturer , and determining appropriate signals containing information about the pressure and flow rate in the pump or system, taking into account the indicated read values of the power and speed of the engine contained in the specified received signals, wherein said processor or processor module for signal processing is configured to: determining the pressure and flow rate in the pump or system at the equilibrium point of pressure in the pump or system at a steady state operation, which is at the intersection of certain curves of the characteristics of the pump and system, determining or providing a representation of the curve of the current pumping characteristics, which illustrates the dependence of the differential pressure P in the pump on the flow rate Q of the flow and engine speed n, by approximation using the polynomial P = ƒ (Q, n) based on the curve of the pumping characteristics at the maximum speed n _{max of the} engine and similarity laws for pumps, and determining the flow rate in the system by successively applying the differential pressure function in the pump of the form P = ƒ (Q, n) and the flow equation in the system

6. The device according to claim 5, wherein said processor or processor module for signal processing is configured to apply the indicated similarity laws for pumps, expressed as the following equations for flow rate in a pump, differential pressure and engine power, respectively: Q / Q _max = n / n _max , P / P _max = (n / n _max ) ² and w / w _max = (n / n _max ) ³ . 7. The device according to claim 6, in which the specified processor or processor module for signal processing is configured to determine the flow rate in the system based on the curve of the characteristics of the second-order pump, converted by the best approximation method, and the flow equation in the system, in the form of the following expression:

where C _v is the coefficient of the system, and a, b and c are the coefficients for the curve of the characteristics of the second-order pump, converted by the best approximation method, at a maximum speed n _{max of the} engine. 8. The device according to claim 7, wherein said processor or processor module for signal processing is configured to use the differential pressure function in the pump P = ƒ (Q, n), expressed as the following Equation (2):

9. The device according to claim 8, in which the specified processor or processor module of the signal processing processor is configured to provide a representation of the engine power function at maximum speed, taking into account the specified coefficient of the system, by approximation or interpolation and determining the engine power at a given engine speed as w = w (C _ν , n) using the indicated similarity law for pumps. 10. The device according to claim 9, in which the specified processor or processor module for signal processing is configured to use the function of engine power, converted using the polynomial of the best approximation of the second order, and representing the coefficient C _{v of the} system in the form of the following Equation:

where w is the engine power at speed n; A, B and C are the coefficients of the engine power function converted using the second-order best approximation polynomial at maximum engine speed, taking into account the normalized coefficient

system. 11. The device according to p. 10, in which the specified processor or processor module for signal processing is configured to represent the specified function of the engine power at any current speed value w = w (C _ν , n) in the form of the following Equation:

12. The device according to p. 10, in which the specified processor or processor module for signal processing is configured to apply the converted similarity law to represent the power and speed of the engine in the form of the following Equations:

where ƒ * (n) is the similarity law transformed by the approximation method using a third-order polynomial into the following equation:

where A ', B' C 'and D' are the coefficients of the power function converted using the third-order polynomial of best approximation, including power values normalized taking into account the ratio of the maximum speed to the normalized engine speed n / n _max . 13. A method of controlling the differential pressure and flow rate in the pump, including: receiving signals by a processor or processor module of the signal processing, and these signals contain information about the read values of the power and speed of the engine, as well as equations of characteristics of the pump and system and empirical equations of power, expressed as a polynomial of best approximation and similarity laws for pumps based on a curve pumping characteristics provided by the pump manufacturer, and determination by means of said processor or processor module of the signal processing of the corresponding signals containing information on pressure and flow rate in the pump or system, based on said read values of engine power and speed contained in the received signals. 14. The method according to p. 13, which includes the stage on which through the specified processor or processor module of the signal processing determine the pressure drop and flow rate in the pump at the pressure equilibrium point in the specified pump or system under steady state engine operation. 15. The method according to p. 13, which includes the stage on which through the specified processor or processor module of the signal processing receive the corresponding signals containing information about the pressure and flow rate in the specified pump or system, including to control the pressure drop and flow rate in the pump . 16. The method of claim 15, wherein said respective signals containing information are used to control the liquid pump system.

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