A multi-stage pump set frequency stage number cooperative control system

Abstract

The application discloses a kind of multistage pump group frequency conversion level number collaborative control system, and the application relates to pump group frequency conversion control technical field, including pump group state monitoring module, noise characteristic database, frequency conversion level number collaborative control module, execution module;By real-time monitoring working condition data and dynamic control, the flow, pressure of pump group combined output is continuously close to demand value, avoid water shortage or pressure surplus, guarantee water supply quality;Significantly reduce pump group operating noise, rely on noise characteristic database to optimize frequency conversion frequency, realize total noise minimum under the condition of meeting working condition demand, improve surrounding sound environment, reduce personnel interference;Can realize energy saving and cost reduction, fine collaborative control each stage pump frequency, avoid energy waste, reduce pump body mechanical wear, prolong equipment life, reduce operation and maintenance cost;It also has strong flexibility and adaptability, can be flexibly set working condition demand according to actual scene, quickly respond to flow, pressure change.

Description

Technical Field

[0001] This invention relates to the field of pump set frequency conversion control technology, specifically a multi-stage pump set frequency conversion stage coordinated control system. Background Technology

[0002] In modern industrial production, urban water supply, and sewage treatment, multistage pump sets are widely used in fluid transport operations due to their advantages of flexibly superimposing flow and pressure parameters and adapting to high-head or high-flow conditions. However, the current operation and control of multistage pump sets still faces many technical bottlenecks, making it difficult to simultaneously meet operational requirements and optimize operational performance. Specific problems are as follows:

[0003] First, traditional variable frequency control (VFD) systems for multi-stage pump sets often employ "single-stage independent adjustment" or "uniform frequency allocation" modes, lacking coordinated management of the operating status of each pump stage. This type of control only roughly sets the VFD parameters based on overall flow or pressure requirements, failing to consider the differences in flow-pressure output characteristics of each pump stage at different frequencies. This easily leads to output mismatch between pump stages—some pumps operate under overload conditions, while others operate inefficiently. This not only makes it difficult to accurately meet the actual flow and pressure demands of the operating conditions but also wastes energy and shortens the overall service life of the pump set.

[0004] Secondly, existing control schemes generally neglect the management of pump unit operating noise. During the operation of multi-stage pump units, the frequency of each pump's variable frequency drive directly affects the noise intensity. Traditional control methods only focus on achieving flow and pressure targets, failing to incorporate noise levels into the control optimization system. With increasing demands on the operating environment from industrial production, and the growing application of pump units in urban water supply systems near residential areas, uncontrolled operating noise not only pollutes the environment and affects human health, but may also restrict pump unit operation and reduce overall operational efficiency due to excessive noise levels.

[0005] Furthermore, traditional pump control systems lack the ability to dynamically adapt to changing operating conditions. In practical applications, the flow and pressure requirements of water supply scenarios vary over time or depending on the usage environment. Existing controls often rely on fixed parameter settings, making it difficult to adjust the frequency of each pump according to real-time operating conditions. This results in frequent flow or pressure deviations in the pump set when operating conditions fluctuate, requiring manual intervention and adjustments. This increases operational complexity and maintenance costs, and also fails to guarantee the stability of fluid delivery.

[0006] In summary, current multi-stage pump control technology has significant shortcomings in terms of precise adaptation to operating conditions, noise control, and operational coordination. There is an urgent need for a control system that can coordinate flow rate, pressure demand, and noise control, and achieve coordinated optimization of frequency conversion of each pump stage, so as to improve the accuracy, economy, and environmental adaptability of pump operation. Summary of the Invention

[0007] Technical problems to be solved

[0008] To address the shortcomings of existing technologies, this invention provides a multi-stage pump group variable frequency stage coordinated control system, which solves the problems mentioned in the background section.

[0009] Technical solution

[0010] To achieve the above objectives, the present invention provides the following technical solution: a multi-stage pump group variable frequency stage coordinated control system, comprising:

[0011] Pump group status monitoring module: During the operation of the pump group, it monitors the flow and pressure of the pump group in real time through flow and pressure sensors to obtain the corresponding real-time operating condition data. It also extracts the operating condition requirement data corresponding to the pre-set flow and pressure values ​​that the pump group needs to achieve. At the same time, during the operation of the pump group, it monitors the operating status of each pump in real time, including the frequency conversion frequency of each pump stage. It also monitors the noise value of the pump group in real time through an external noise sensor. The captured real-time operating condition data, operating condition requirement data, operating status of each pump in the pump group, and noise value of the pump group in real time are transmitted to the frequency conversion stage collaborative control module.

[0012] Noise characteristics database: used to store the noise values ​​of each pump stage at different frequency conversion frequencies, as well as the corresponding flow rate and pressure;

[0013] Variable frequency stage coordinated control module: used to coordinately control the variable frequency of each pump in a multi-stage pump group based on the operating condition data provided by the pump group status monitoring module and the data in the noise characteristic database;

[0014] Execution module: Used to receive control commands generated by the variable frequency stage coordinated control module, and adjust the preset variable frequency device corresponding to each pump according to the control commands, so that each pump operates at the optimized variable frequency frequency.

[0015] As a further aspect of the present invention: the operating condition requirement data is determined by the staff on the central control system or operating terminal, based on the actual water supply scenario, by pre-setting the flow rate and pressure values ​​that the pump set needs to achieve, and then sending them to the pump set status monitoring module through a data transmission line.

[0016] As a further aspect of the present invention: for a pump group containing n pumps, they are respectively denoted as pump 1, pump 2, ..., pump n, where n represents the number of pumps in the multi-stage pump group;

[0017] Let the flow rate, representing pump i, be denoted as q. i Let the pressure of pump i be denoted as p. i Let the frequency of pump i be denoted as f. i , i = 1, 2, ..., n.

[0018] As a further aspect of the present invention, the noise characteristic database is constructed as follows:

[0019] Individual variable frequency operation experiments were conducted for each stage of the pump: for pump i, starting from a low frequency f i,1 Start by gradually increasing to a high frequency f i,m Where m is the number of frequency conversion operation experiments at different frequency conversion frequencies;

[0020] At the frequency conversion frequency f i,j Below, a noise sensor is used to measure the noise level N of pump i during operation. i (f i,j Simultaneously, flow sensors and pressure sensors are used to record the pump's operation at the variable frequency f. i,j The traffic q below i,j and pressure p i,j Where j is the variable frequency operation experiment number, j=1, 2, ..., m;

[0021] The noise, flow, and pressure data collected for each pump stage at different frequency conversions were categorized and organized.

[0022] As a further aspect of the present invention, the classification and organization method is as follows: an index is established according to the number of pump stages and the frequency conversion frequency, and then stored in the noise characteristic database.

[0023] As a further aspect of the present invention, the collaborative control method of the frequency conversion stage collaborative control module is as follows:

[0024] Based on the noise characteristic database, a variable frequency is initially assigned to each pump stage, so that when each pump operates at this variable frequency, the total flow and pressure values ​​provided by the combined pumps make the real-time operating data close to the operating requirements data.

[0025] The initial allocation method for each pump stage corresponding to a variable frequency is as follows: pump i is initially allocated a variable frequency, denoted as f. i,c Meanwhile, a query was performed from the noise characteristic database to find that pump i in f i,c The flow rate is denoted as q. i，c Pump i in f i,c The pressure below is denoted as p. i，c ;

[0026] Then, by using q from i=1 to i=n i,c Summation is performed to calculate the initial total flow rate Q provided by all pumps combined. c , and by using p from i=1 to i=n i,c Summation is performed to calculate the initial total pressure P provided by all pumps combined. c ;

[0027] Next, subtract the initial total flow value Q from the flow value in the operating condition demand data.c Calculate the flow deviation ΔQ after the initial frequency allocation, and subtract the initial total pressure value P from the pressure value in the operating condition demand data. c Calculate the pressure deviation ΔP after the initial allocation of the variable frequency;

[0028] The frequency converter frequency of each pump is adjusted based on the flow deviation ΔQ and pressure deviation ΔP, as follows:

[0029] By considering N from i=1 to i=n i (f i The noise levels of each pump are summed to calculate the total noise level N of the pump unit. z N i (f i ) is the pump i at the variable frequency frequency f i Noise level during runtime;

[0030] Subsequently, a set of frequency converters f1, f2, ... f were found. n ;

[0031] So that when: Under the condition of N z Minimum value;

[0032] In the formula, q i (f) i ) refers to the flow rate of pump i at the corresponding strain frequency, p i (f) i The pressure of pump i at the corresponding variable frequency is represented by Q, and Q and P are the total flow rate and total pressure provided by each pump in combination at a set of variable frequency frequencies, respectively.

[0033] As a further aspect of the present invention: the frequency conversion search process adopts a step-by-step iterative approach.

[0034] For each pump stage, within the adjustable range of its variable frequency, change its variable frequency. After each change of the variable frequency of pump i, query the flow rate, pressure and noise value of pump i at the new variable frequency from the noise characteristic database.

[0035] Next, calculate the total flow rate and pressure provided by all pumps in the pump set at this time, as well as the sum of the noise levels of each pump;

[0036] Then, the flow rate deviation and pressure deviation between the total flow rate and total pressure provided by each pump and the operating condition requirements are calculated, and the real-time operating condition data are determined to be close to the operating condition requirements based on the flow rate deviation and pressure deviation.

[0037] Repeat the above process, continuously adjusting the frequency of each pump, and determining the frequency at which the total noise of the pump set reaches a relatively minimum among all frequency adjustments;

[0038] Finally, the variable frequency stage coordinated control module generates the corresponding control commands and sends them to the execution module.

[0039] As a further aspect of the present invention, the method for determining whether real-time operating condition data closely approximates operating condition demand data is as follows:

[0040] If at least one of the comparison criteria is not met, either the flow deviation is less than the corresponding preset flow deviation threshold or the pressure deviation is less than the corresponding preset pressure deviation threshold, it indicates that the real-time operating data deviates from the operating requirement data.

[0041] If both the flow deviation and the pressure deviation are less than the corresponding preset flow deviation threshold and the pressure deviation are less than the corresponding preset pressure deviation threshold, it indicates that the real-time operating data is close to the operating requirement data.

[0042] As a further aspect of the present invention: when the real-time operating data is close to the operating requirement data,

[0043] The total noise of the pump unit at this time is compared with the total noise of the pump unit before the frequency conversion adjustment. If the total noise of the pump unit at this time is lower than the total noise of the pump unit before the frequency conversion adjustment, the frequency conversion adjustment is retained. If the total noise of the pump unit at this time is higher than the total noise of the pump unit before the frequency conversion adjustment, the frequency conversion adjustment is cancelled.

[0044] As a further aspect of the present invention: during the iterative adjustment of the frequency converter, all frequency converter adjustment results that meet the real-time operating data and are close to the operating requirements are retained. Finally, among all frequency converter adjustment schemes, the frequency converter with the smallest total noise value of the pump group is selected and determined as the target frequency converter where the total noise of the pump group reaches a relatively minimum state within all effective adjustment ranges.

[0045] As a further aspect of the present invention, the control command specifies the frequency to which each pump should be adjusted, i.e., the optimized frequency.

[0046] This invention provides a multi-stage pump group variable frequency stage coordinated control system. Compared with the prior art, it has the following advantages:

[0047] By real-time monitoring and dynamic control of core operating data such as pump flow and pressure, the flow and pressure output of multi-stage pump sets can be made to continuously approach the demand value of the actual water supply scenario. This effectively avoids water shortage or pressure excess caused by deviations in operating conditions, providing stable and reliable water pressure and quantity guarantees for different water use scenarios (such as residential daily water supply and industrial production water), and improving the overall quality of water supply services.

[0048] By constructing a noise characteristic database, the noise performance of pumps at different levels under various variable frequency drives (VFDs) can be accurately grasped. Based on this, the VFD frequencies can be optimized collaboratively to find the operating scheme with the lowest total noise level for the pump set while meeting operational requirements. This design effectively alleviates the problem of excessive noise during the operation of traditional pump sets. Whether applied to water supply pumping stations near residential areas or noise-sensitive industrial plants, it can effectively improve the acoustic environment quality of the surrounding environment and reduce noise interference to workers and nearby residents.

[0049] By precisely and collaboratively controlling the frequency of each pump stage, energy waste caused by excessively high frequencies or unreasonable operating conditions is avoided. Compared to traditional, rudimentary pump control methods, this system can dynamically adjust the operating frequency of each pump stage according to actual operating conditions, ensuring the pump set always operates close to its optimal efficiency and effectively reducing energy consumption. Simultaneously, a reasonable operating frequency also reduces mechanical wear on the pump body, extends the pump set's service life, lowers equipment maintenance and replacement costs, and brings significant economic benefits to the enterprise.

[0050] Because the operating conditions and demand data can be flexibly set by the staff according to the actual water supply scenario, the system can quickly respond to the flow and pressure changes in different scenarios. Whether it is a large flow of water supply during peak water use or a small flow of water with stable pressure during off-peak hours, it can achieve precise adaptation by adjusting the frequency of the variable frequency of each pump. Attached Figure Description

[0051] Figure 1 This is a system block diagram of a multi-stage pump group variable frequency stage coordinated control system according to the present invention. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Please see Figure 1 As shown, the embodiments of the present invention provide the following technical solutions:

[0054] As an embodiment of the present invention:

[0055] This invention relates to a multi-stage pump group variable frequency stage coordinated control system, comprising:

[0056] Pump unit status monitoring module: Used to monitor the flow rate Q0={q1, q2, ... q0} of the pump unit in real time during operation via flow and pressure sensors. n} and pressure P0={p1, p2, ... p n The system receives real-time operating data and transmits the captured flow and pressure signals to the variable frequency drive (VFD) collaborative control module.

[0057] Where i = 1, 2, ..., n, n represents the number of pump stages in the multistage pump group, that is, the pump group contains n pump stages, which are denoted as pump 1, pump 2, ..., pump n respectively, q i p refers to the flow rate of pump i. i Refers to the pressure of pump i;

[0058] And extract the pre-set flow rate value Q that the pump set needs to achieve. X and pressure value P X Corresponding operating condition requirements data;

[0059] In this embodiment, the operating condition demand data is set by the staff on the central control system or operating terminal according to the actual water supply scenario, such as the water usage patterns of hospitals and residential areas at different times, peak and trough water usage, etc., and the flow rate and pressure value that the pump set needs to reach are preset and sent to the pump set status monitoring module through the data transmission line.

[0060] Meanwhile, the operating status of each pump is monitored in real time during the operation of the pump set;

[0061] Operating status includes the frequency f of each pump stage. i ;

[0062] In addition, the noise level of the pump unit during operation can be monitored in real time through an external noise sensor;

[0063] In actual operation, due to minor changes in operating conditions, such as slight fluctuations in water demand, the flow rate or pressure of the pump set may deviate from the demand, or the noise level may deviate significantly from the expected minimum noise level. The pump set status monitoring module will quickly feed back these deviation data to the variable frequency stage collaborative control module, triggering the system to restart the variable frequency stage collaborative control process to readjust the frequency conversion frequency of each pump, ensuring that the pump set always maintains low operating noise while meeting the operating condition requirements.

[0064] Noise characteristics database: used to store the noise values ​​of each pump stage at different frequency conversion frequencies, as well as the corresponding flow rate and pressure;

[0065] The noise characteristics database was pre-built.

[0066] Variable frequency stage coordinated control module: used to coordinately control the variable frequency of each pump in a multi-stage pump group based on the operating condition data provided by the pump group status monitoring module and the data in the noise characteristic database;

[0067] Step K1, Preliminary frequency allocation:

[0068] Based on the noise characteristic database, a variable frequency is initially assigned to each pump stage, so that when each pump operates at this variable frequency, the total flow and pressure values ​​provided by the combined pumps make the real-time operating data close to the operating requirements data.

[0069] The method is as follows:

[0070] Pump 1 is initially assigned a variable frequency, denoted as f. 1,c Meanwhile, a query was performed from the noise characteristic database to find that pump 1 was at f 1,c The flow rate is denoted as q. 1，c Pump 1 in f 1,c The pressure below is denoted as p. 1，c ;

[0071] Pump 2 is initially assigned a variable frequency, denoted as f. 2,c Meanwhile, a query was performed from the noise characteristic database to find that pump 2 was at f 2,c The flow rate is denoted as q. 2，c Pump 2 in f 2,c The pressure below is denoted as p. 2，c ;

[0072] And so on:

[0073] Initially assign a variable frequency to pump n, denoted as f. n,c Meanwhile, a query was performed from the noise characteristic database to find that pump n in f n,c The flow rate is denoted as q. n，c Pump n in f n,c The pressure below is denoted as p. n，c c refers to the result corresponding to the initial allocation;

[0074] Then through:

[0075] Calculate the initial total flow rate Q provided by all pumps combined. c and the initial total pressure value P c ;

[0076] Then proceed as follows:

[0077] After calculating the initial allocation of the variable frequency drive, the initial total flow rate Q provided by each pump in combination is... c and the initial total pressure value P c The flow rate deviation ΔQ and pressure deviation ΔP are respectively compared with the operating condition demand data;

[0078] In the formula, Q X and P X These are the flow rate and pressure values ​​from the operating condition demand data, respectively.

[0079] When both the flow deviation ΔQ and the pressure deviation ΔP are less than the corresponding preset flow deviation threshold, it indicates that the real-time operating data is close to the operating requirement data.

[0080] If at least one of the comparison equations is not true, it means that the real-time operating data deviates from the operating condition requirement data.

[0081] Step K2, Frequency Conversion Adjustment and Optimization:

[0082] The frequency converter frequency of each pump is adjusted based on the flow deviation ΔQ and pressure deviation ΔP, as follows:

[0083] pass:

[0084] Calculate the sum of the noise values ​​of each pump, i.e., the total noise N of the pump set. z ;

[0085] Subsequently, a set of frequency converters f1, f2, ... f were found. n ;

[0086] So that when: Under the condition of N z Minimum value;

[0087] In the formula, q i (f) i ) refers to the flow rate of pump i at the corresponding strain frequency, p i (f) i ) refers to the pressure of pump i at the corresponding variable frequency; Q and P are the total flow rate and total pressure provided by all pumps in combination at the corresponding variable frequency, respectively;

[0088] The frequency search process employs a step-by-step iterative approach:

[0089] For each pump stage, within the adjustable range of its variable frequency, change its variable frequency. After each change of the variable frequency of pump i, query the flow rate, pressure and noise value of pump i at the new variable frequency from the noise characteristic database.

[0090] Next, calculate the total flow rate and pressure provided by all pumps in the pump set at this time, as well as the sum of the noise levels of each pump;

[0091] Then, the flow rate and pressure deviations between the total flow rate and total pressure provided by each pump and the operating condition requirements are calculated.

[0092] When both the flow deviation and the pressure deviation are less than the corresponding preset flow deviation threshold and the pressure deviation are less than the corresponding preset pressure deviation threshold, it indicates that the real-time operating data is close to the operating requirement data.

[0093] At the same time, the total noise of the pump group at this time is compared with the total noise of the pump group before the frequency conversion adjustment. If the total noise of the pump group at this time is lower than the total noise of the pump group before the frequency conversion adjustment, the frequency conversion adjustment is retained.

[0094] If the total noise of the pump unit is higher than the total noise of the pump unit before the frequency conversion adjustment, then the frequency conversion adjustment is cancelled.

[0095] If at least one of the comparison criteria is not met, either the flow deviation is less than the corresponding preset flow deviation threshold or the pressure deviation is less than the corresponding preset pressure deviation threshold, it indicates that the real-time operating data deviates from the operating demand data, and the frequency conversion adjustment is cancelled.

[0096] Repeat the above process, continuously adjusting the frequency of each pump until the flow deviation of the pump group is less than the corresponding preset flow deviation threshold and the pressure deviation is less than the corresponding preset pressure deviation threshold, and the total noise of the pump group reaches a relatively minimum state among all frequency adjustments.

[0097] Finally, the variable frequency stage coordinated control module generates the corresponding control commands and sends them to the execution module;

[0098] The control instructions specify the frequency to which each pump should be adjusted, i.e., the optimized frequency.

[0099] The execution module receives control commands generated by the variable frequency stage coordinated control module and adjusts the preset variable frequency device corresponding to each pump according to the control commands, so that each pump operates at the optimized variable frequency frequency.

[0100] This embodiment uses a pump set status monitoring module to monitor the pump set's operational data, such as flow rate, pressure, and noise, in real time. Combined with a variable frequency drive (VFD) stage collaborative control module, it performs coordinated optimization control of the VFD frequencies of multiple pump sets. It first performs an initial VFD frequency allocation, and then adjusts the frequency of each pump through a gradual iterative process. While ensuring that the pump set's flow rate and pressure meet the operating conditions, it effectively reduces the overall noise of the pump set, achieving a balance between operating requirements and low-noise operation. Simultaneously, the system can quickly respond to and readjust to minor changes in operating conditions and noise deviations, ensuring stable and efficient operation of the pump set under different water usage scenarios, and improving the reliability and economy of the water supply system.

[0101] As a second embodiment of the present invention:

[0102] In its specific implementation, compared to Embodiment 1, the technical solution of this embodiment differs from that of Embodiment 1 only in that this embodiment also proposes a method for constructing a noise characteristic database, as detailed below:

[0103] Step A1, Experimental Data Collection:

[0104] Perform individual variable frequency operation experiments on each stage of the pump:

[0105] Taking pump 1 as an example, from a low frequency f 1,1 Start by gradually increasing to a high frequency f 1,m ;

[0106] Where m represents the number of frequency conversion operation experiments at different frequency conversion frequencies;

[0107] At each frequency f 1,j Below, the noise level N1(f) of pump 1 during operation is measured using a noise sensor. 1,j Simultaneously, flow sensors and pressure sensors are used to record the flow rate q that the pump can provide at this frequency. 1,j and pressure p 1,j ;

[0108] Where j is the variable frequency operation experiment number, j=1, 2, ..., m;

[0109] For other pump stages: pump 2, pump 3, ... pump n, conduct experiments according to the same logic as pump 1, and collect noise values, flow rates and pressures at different frequency conversion frequencies.

[0110] Step A2, Data Processing and Storage:

[0111] The noise, flow, and pressure data collected for each pump stage at different frequency conversion frequencies were categorized and organized as follows:

[0112] An index is created based on the number of pump stages and the frequency conversion frequency, and then stored in the noise characteristic database;

[0113] When the variable frequency stage coordinated control module queries the noise, flow, and pressure of each pump stage at a specific variable frequency, it can quickly obtain the corresponding data from the database, providing a basis for adjusting and optimizing the variable frequency.

[0114] This embodiment clarifies the construction method of the noise characteristic database. By conducting experiments on each pump stage at different frequency conversion frequencies, the system collects and stores the noise value, flow rate, and pressure data of each pump at the corresponding frequency. This pre-built database provides accurate and reliable data support for the coordinated control of frequency conversion stages, enabling the control module to quickly obtain accurate information when querying and adjusting the frequency conversion of each pump. This ensures the scientific and efficient nature of frequency conversion adjustment and optimization, laying a solid data foundation for the stable operation of the entire control system.

[0115] As an embodiment of the present invention:

[0116] In specific implementation, compared with Embodiment 1 and Embodiment 2, the technical solution of this embodiment is to combine the solutions of Embodiment 1 and Embodiment 2.

[0117] This embodiment combines the variable frequency stage collaborative control scheme of Embodiment 1 with the noise characteristic database construction scheme of Embodiment 2. It possesses both real-time monitoring and collaborative optimization control functions to meet operating conditions and reduce noise, and a scientifically constructed database as data support. This combination enables the system to achieve precise frequency adjustment based on a comprehensive database during operation, and to dynamically respond to changes in operating conditions through a collaborative control mechanism. This further improves the stability, efficiency, and low noise characteristics of the pump unit, balancing the scientific nature and practicality of the control, and making it suitable for more complex water supply scenarios.

[0118] It should be stated that all user data collected in this application was collected with the user's consent and authorization, and the use of user data is legal and compliant, and the use and processing of user data comply with the relevant laws, regulations and standards of the relevant regions.

[0119] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0120] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0121] The above formulas are all dimensionless calculations. Dimensionless calculation involves introducing a reference benchmark, such as the maximum, minimum, standard deviation, or theoretical extreme value of a physical quantity, to transform the original physical quantity into a dimensionless relative value. This value is usually mapped to a specific interval, such as [0,1] or [-1,1], which eliminates the influence of units while preserving the relative size relationship of the physical quantities. The formula is derived from software simulation based on a large amount of collected data to obtain the most recent real-world results. The preset parameters and thresholds in the formulas are set by those skilled in the art according to the actual situation.

[0122] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0123] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A multi-stage pump set variable frequency stage number cooperative control system, characterized in that, Comprise: Pump set state monitoring module: for in the process of pump set operation, through the flow sensor and pressure sensor, real-time monitoring of pump set flow and pressure corresponding real-time working condition data, and extract the pre-set pump set needs to reach the flow value and pressure value corresponding working condition demand data, at the same time, in the process of pump set operation, real-time monitoring of each pump running state, running state includes each stage pump frequency, and through the external noise sensor, real-time monitoring of pump set running noise value, and the captured real-time working condition data, working condition demand data, pump set in each pump running state, and the noise value of pump set running is transmitted to the frequency number collaborative control module; For pump set contains n stage pump, it is respectively recorded as pump 1, pump 2, … Pump n, n represents the number of pump in multi-stage pump set; Let the flow rate of pump i be denoted as q i Let the pressure of pump i be denoted as p i Let the variable frequency of pump i be denoted as f i i = 1, 2,... n; Noise characteristic database: for storing each stage pump at different frequency of noise value, flow, pressure; Noise characteristic database construction method as follows: For each stage pump, separate variable frequency operation experiment is carried out: for pump i, from low frequency f i,1 to high frequency f i,m ; wherein m is the number of variable frequency operation experiments at different variable frequencies. At variable frequency f i,j Next, the noise value N of the pump i in operation is measured using a noise sensor i (f i,j ), while the flow rate q i,j and pressure p i,j of the pump at variable frequency f i,j are recorded using a flow sensor and a pressure sensor; wherein j is the variable frequency operation experiment number, j = 1, 2, … m. After collecting each stage pump at different frequency of noise value, flow, pressure data classification arrangement; Classification arrangement mode is: according to the number of pump and frequency of establishment index, then store in noise characteristic database; Variable frequency number collaborative control module: for according to the working condition demand data provided by pump set state monitoring module and the data in noise characteristic database, the frequency of each stage pump in multi-stage pump set is controlled collaboratively, and then the corresponding control instruction is generated based on the result of collaborative control and sent to the execution module; The collaborative control mode of the variable frequency number collaborative control module is as follows: According to the noise characteristic database, a frequency of each stage pump is preliminarily allocated, so that the total flow value and pressure value provided by the pumps are close to the real-time working condition data when the pumps run at the frequency. The initial allocation method for each pump stage corresponding to a variable frequency is as follows: pump i is initially allocated a variable frequency, denoted as f. i,c Meanwhile, a query was performed from the noise characteristic database to find that pump i in f i,c The flow rate is denoted as q. i，c Pump i in f i,c The pressure below is denoted as p. i，c ; The preliminary total flow value Q provided by the pumps in combination is then calculated by summing q i,c from i = 1 to i = n c , and the preliminary total pressure value P provided by the pumps in combination is calculated by summing p i,c from i = 1 to i = n c ; Then the flow value in the working condition requirement data is subtracted from the preliminary total flow value Q c , the deviation ΔQ of the flow after the preliminary allocation of the variable frequency frequency is calculated, and the pressure value in the working condition requirement data is subtracted from the preliminary total pressure value P c , the deviation ΔP of the pressure after the preliminary allocation of the variable frequency frequency is calculated. According to the flow deviation ΔQ and pressure deviation ΔP, the frequency of each pump is adjusted, and the method is as follows: The total sum of the pump noise values, i.e. the total noise N i (f i ) of the pump group is calculated by summing the values of the noise of each pump i from i = 1 to i = n z , N i (f i ) being the noise value of the pump i when it is operating at the variable frequency f i . A set of varying frequencies f1, f2,... f n is sought. such that N is minimized subject to: z the condition that the value of N is minimized. where q i (f i ) denotes the flow rate of pump i at the corresponding variable frequency, p i (f i ) denotes the pressure of pump i at the corresponding variable frequency; Q and P are the total flow rate and total pressure provided by the pumps in combination at a set of variable frequencies, respectively. The execution module is used for receiving the control instruction generated by the variable frequency number collaborative control module, and adjusting the corresponding preset frequency conversion device of each stage pump according to the control instruction, so that each pump runs at the optimized frequency.

2. The multi-stage pump group variable frequency stage number cooperative control system according to claim 1, characterized in that: The variable frequency frequency finding process adopts step-by-step iteration method: For each stage pump, change its frequency within the adjustable range of frequency, and query the flow, pressure and noise value of pump i at the new frequency from the noise characteristic database after changing the frequency of pump i each time; Then calculate the total flow value and pressure value provided by each pump, and the total of each pump noise value; Then calculate the flow deviation and pressure deviation between the total flow value and pressure value provided by each pump and the working condition demand; And according to the flow deviation and pressure deviation, determine whether the real-time working condition data is close to the working condition demand data; Then by constantly adjusting the frequency of each pump, and determining the frequency of the relative minimum state of the total noise of the pump set in all frequency adjustments.

3. The variable frequency stage number coordinated control system of a multi-stage pump set according to claim 2, characterized in that: The determination method of real-time working condition data close to working condition demand data is as follows: If at least one of the following conditions is not met: the flow deviation is less than the corresponding preset flow deviation threshold, and the pressure deviation is less than the corresponding preset pressure deviation threshold, it is determined that the real-time working condition data deviates from the working condition demand data. If all of the following conditions are met: the flow deviation is less than the corresponding preset flow deviation threshold, and the pressure deviation is less than the corresponding preset pressure deviation threshold, it is determined that the real-time working condition data is close to the working condition demand data.

4. The variable frequency stage number coordinated control system of a multi-stage pump set according to claim 3, characterized in that: In the case that the real-time working condition data is close to the working condition demand data, the total noise of the pump group at this time is compared with the total noise of the pump group before the frequency adjustment: When the total noise of the pump group at this time is lower than the total noise of the pump group before the frequency adjustment, the frequency adjustment is retained; When the total noise of the pump group at this time is higher than the total noise of the pump group before the frequency adjustment, the frequency adjustment is cancelled.

5. The variable frequency stage number coordinated control system of a multi-stage pump set according to claim 4, characterized in that: In the process of gradually iterating the frequency adjustment, all frequency adjustment results that meet the condition that the real-time working condition data is close to the working condition demand data are retained. Finally, among all the frequency adjustment schemes, the frequency with the minimum total noise of the pump group is selected as the target frequency, which is determined as the target frequency for achieving the relative minimum state of the total noise of the pump group within all effective adjustment ranges.

6. The variable frequency stage number coordinated control system of a multi-stage pump set according to claim 1, characterized in that: The control instruction explicitly indicates the frequency to which each stage of the pump should be adjusted, i.e., the optimized frequency.

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