Centrifugal water pump operation efficiency and temperature rise trend early warning method and system

Abstract

This application discloses a method and system for early warning of operating efficiency and temperature rise trend of a centrifugal water pump. The method includes: real-time acquisition of the pump motor's input electrical power, outlet pressure, and ambient temperature; establishing the relationship between pressure and flow characteristics, estimating the actual output flow rate and calculating the output hydraulic power, and obtaining the operating efficiency by combining the input electrical power; estimating the equivalent temperature of the motor windings based on the input electrical power, operating efficiency, and temperature, and calculating the temperature change rate; triggering a first early warning signal when the operating efficiency shows a downward trend and reaches a preset condition, and triggering a second early warning signal when the temperature change rate shows an upward trend and reaches a preset condition; issuing an early warning based on the early warning signals and cooling requirements, and adjusting the operating state. This application effectively solves the problem that traditional control systems cannot detect insufficient actual flow and accumulated motor heat load through a dual early warning mechanism of efficiency decline and temperature rise rate increase.

Description

Technical Field

[0001] This application relates to the field of electrical control technology for centrifugal water pumps, and in particular to an early warning system for the operating efficiency and temperature rise trend of centrifugal water pumps. Background Technology

[0002] In continuous process industrial production sectors such as chemical engineering, metallurgy, and automobile manufacturing, cooling water circulation systems are critical infrastructure for maintaining the stable operation of production line equipment. Taking the painting workshop of an automotive parts factory as an example, the electrophoretic coating line and painting robots need to operate within a constant temperature range, requiring cooling volumes of hundreds of tons per hour. The core power source is a high-power centrifugal water pump. These pumps typically run continuously for months or even a year without interruption, and their operational reliability directly determines the availability of the production line. Traditional centrifugal pump electrical control mainly relies on mechanical pressure switches or programmable logic controllers based on electronic pressure sensors. The system status is determined by monitoring the pump outlet pressure, and the pump operating frequency is adjusted to maintain the set water pressure within the pipeline network. This control method, using pressure as the single monitoring variable, can meet basic needs under conditions of good water quality and clean pipelines during the initial system commissioning. However, as operating time increases, deeper monitoring blind spots gradually emerge.

[0003] During long-term high-temperature, high-speed circulation, dissolved minerals and suspended particles in the cooling water gradually deposit on the heated surfaces of heat exchangers and in low-flow-rate areas of the pipes, forming scale and causing a continuous increase in system hydraulic resistance. This scale accumulation is a slow, gradual process, taking anywhere from several weeks to several months, and it shows almost no abnormal reaction in the pump outlet pressure—because the pressure sensor measures the static pressure at the pump outlet, not the actual flow rate. Therefore, existing control systems, based on pressure feedback, may mistakenly assume the system is "normal," when in reality the cooling water flow rate is continuously decreasing due to increased pipe resistance, and the cooling capacity of the production equipment is gradually becoming insufficient. This hidden fault mode of "normal pressure but insufficient actual flow" makes it difficult for maintenance personnel to detect the problem during routine inspections, often only realizing the fault when the equipment experiences overheating alarms or the motor burns out. Furthermore, scale accumulation also affects pump characteristics by gradually reducing operating efficiency; that is, the actual output hydraulic power decreases under the same input power, and this efficiency degradation trend is also undetectable in existing control schemes.

[0004] Meanwhile, to overcome increased resistance and maintain outlet pressure, the water pump is forced to operate at a higher head, causing the actual load and power consumption of the motor to continuously increase. However, traditional overcurrent protection devices are designed to handle sudden faults such as short circuits and severe overloads. Their operating thresholds are typically set several times the rated current, and they have delay characteristics ranging from seconds to tens of seconds, making them unable to respond to this slow load increase measured in months. During the gradual increase in load, the motor remains under slight overload for an extended period, causing the winding temperature to accumulate continuously, accelerating insulation aging, and potentially leading to insulation breakdown and sudden burnout without warning.

[0005] In summary, the existing control system relies solely on pressure sensor feedback for judgment, which has two core flaws: First, although the increased pipe resistance caused by scale buildup leads to a continuous decrease in the actual cooling water flow, the change in the pump outlet pressure reading is minimal, making it impossible for the control system to detect the severe deficiency in actual cooling capacity, and maintenance personnel cannot discover the hidden fault of continuously decreasing cooling flow. Second, the load on the motor due to the increased resistance increases very slowly, always remaining below the operating threshold of traditional overcurrent protection devices, causing the hidden danger of "normal pressure but insufficient flow" to be overlooked. Third, it cannot detect the gradual accumulation of internal thermal load in the motor, resulting in traditional overcurrent protection failing to provide effective early warning before a fault occurs. Summary of the Invention

[0006] This application provides a method and system for early warning of centrifugal water pump operating efficiency and temperature rise trend, which at least solves the problems of increased system resistance caused by scale and dirt accumulation during long-term operation of centrifugal water pumps in existing cooling water circulation systems, leading to motor overload, insufficient cooling flow and eventual motor burnout, while existing control systems cannot effectively warn of these potential faults.

[0007] In a first aspect, this application provides a method for early warning of the operating efficiency and temperature rise trend of a centrifugal water pump, comprising the following steps: Real-time data collection of the pump motor's input power, pump outlet pressure, and ambient temperature. Establish the characteristic relationship between pump pressure and flow rate, estimate the actual output flow rate based on the outlet pressure and the characteristic relationship, calculate the pump output hydraulic power based on the actual output flow rate and the outlet pressure, and obtain the pump motor operating efficiency by combining the input electrical power. The equivalent temperature of the motor windings is estimated based on the input power, the operating efficiency, and the temperature, and the rate of temperature change of the motor windings is calculated based on the change in the equivalent temperature. When the operating efficiency shows a downward trend and the downward trend reaches a preset efficiency decline condition, a first warning signal is triggered; when the temperature change rate shows an upward trend and the upward trend reaches a preset temperature rise rate increase condition, a second warning signal is triggered. Based on the first or second warning signal and the cooling requirements of the production line, an early warning is issued and the operating status of the water pump is adjusted.

[0008] Secondly, this application provides a centrifugal water pump operating efficiency and temperature rise trend early warning system, the system comprising: The data acquisition module is used to collect the input power of the water pump motor, the outlet pressure of the water pump, and the temperature of the water pump operating environment in real time. The efficiency evaluation module is used to establish the characteristic relationship between pump pressure and flow rate, estimate the actual output flow rate based on the outlet pressure and the characteristic relationship, calculate the output hydraulic power of the pump based on the actual output flow rate and the outlet pressure, and obtain the operating efficiency of the pump motor by combining the input electrical power. The temperature rise assessment module is used to estimate the equivalent temperature of the motor windings based on the input power, the operating efficiency, and the temperature, and to calculate the rate of temperature change of the motor windings based on the change in the equivalent temperature. The early warning triggering module is used to trigger a first early warning signal when the operating efficiency shows a downward trend and the downward trend reaches a preset efficiency decline condition, and to trigger a second early warning signal when the temperature change rate shows an upward trend and the upward trend reaches a preset temperature rise rate increase condition. The response control module is used to issue an early warning and adjust the operating status of the water pump based on the first early warning signal or the second early warning signal and the cooling requirements of the production line.

[0009] Thirdly, this application provides a computer device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described in the first aspect.

[0010] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0011] Compared with related technologies, the centrifugal water pump operating efficiency and temperature rise trend early warning method and system provided in this application have at least the following technical effects: By comprehensively monitoring the input power, outlet pressure, and ambient temperature of the water pump motor, a pressure-flow characteristic relationship is established to estimate the actual output flow rate, and then the operating efficiency of the water pump is calculated. This effectively identifies the efficiency decline trend caused by scale accumulation, overcoming the deficiency of traditional control systems that cannot detect insufficient actual cooling flow rate by relying solely on pressure readings. At the same time, by estimating the equivalent temperature of the motor windings based on the input power, operating efficiency, and temperature, and calculating the rate of temperature change, the accumulation trend of internal heat load of the motor can be captured from a thermodynamic perspective, enabling early warning of potential overload risks of the motor and avoiding the problem that traditional overcurrent protection devices cannot respond to slow heat accumulation due to their time delay characteristics.

[0012] In summary, this application, through a dual early warning mechanism of efficiency decline and temperature rise rate increase, can issue targeted early warning signals at different stages of fault development, enabling maintenance personnel to take timely countermeasures and effectively avoid sudden motor burnout and unexpected production line shutdowns.

[0013] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0014] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart illustrating a method for early warning of centrifugal water pump operating efficiency and temperature rise trend according to an exemplary embodiment.

[0015] Figure 2 This is a flowchart illustrating the zero-point drift correction of the pressure sensor in step S10 according to an exemplary embodiment.

[0016] Figure 3 This is a flowchart illustrating the triggering of the efficiency degradation condition in step S40 according to an exemplary embodiment.

[0017] Figure 4 This is a flowchart illustrating the triggering of the temperature rise rate condition in step S40 according to an exemplary embodiment.

[0018] Figure 5 This is a flowchart illustrating the early warning response control in step S50 according to an exemplary embodiment.

[0019] Figure 6 This is a block diagram illustrating a centrifugal water pump operating efficiency and temperature rise trend early warning system according to another exemplary embodiment. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0021] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0022] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0023] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship. The terms "first," "second," and "third" used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0024] Example 1 This invention provides a method for early warning of centrifugal water pump operating efficiency and temperature rise trend. Figure 1 This is a flowchart illustrating a method for early warning of centrifugal water pump operating efficiency and temperature rise trend, according to an exemplary embodiment. Figure 1 As shown, the method includes the following steps: S10. Real-time acquisition of the pump motor's input power, pump outlet pressure, and pump operating environment temperature.

[0025] In this step, a three-phase power transmitter (such as a Hall sensor or Rogowski coil power meter) installed on the power supply circuit of the water pump motor collects the input electrical power of the motor in real time at a sampling frequency of not less than 1Hz. An industrial-grade pressure transmitter (with a range selected according to the rated head of the water pump and an accuracy of not less than 0.5) installed on the water pump outlet pipeline collects the outlet pressure in real time at the same sampling frequency. A digital temperature sensor installed in the pump room or control cabinet collects the temperature of the water pump operating environment in real time. The collected power, pressure, and temperature data are transmitted in real time to the industrial controller for processing and storage via RS485 or Ethernet bus.

[0026] S20. Establish the characteristic relationship between pump pressure and flow rate, estimate the actual output flow rate based on the outlet pressure and the characteristic relationship, calculate the pump output hydraulic power based on the actual output flow rate and the outlet pressure, and obtain the pump motor operating efficiency by combining the input electrical power.

[0027] In this step, the characteristic relationship between pump pressure and flow rate is obtained from the performance curve plotted by the pump manufacturer during factory testing. This curve describes the flow output relationship of the pump at different heads. During the pump installation and commissioning phase, the head-flow rate data at different operating points are entered into the parameter database of the control system to form a digital performance curve table. In actual operation, based on the corrected outlet pressure value (corresponding to the actual pump head), the corresponding actual output flow rate is estimated from the digital performance curve through database lookup or linear interpolation. For variable frequency speed control pumps, the performance curve also needs to be similarly converted according to the current operating frequency to obtain the flow rate value at the corresponding frequency. Then, the output hydraulic power is calculated according to the following formula: in, The density of water, It is the acceleration due to gravity. Head (i.e., the height of the water column corresponding to the outlet pressure). This represents the actual output flow rate. Operating efficiency. Then calculate according to the following formula: in, This refers to the input electrical power.

[0028] S30. Estimate the equivalent temperature of the motor windings based on the input power, the operating efficiency, and the temperature, and calculate the rate of temperature change of the motor windings based on the change in the equivalent temperature.

[0029] In this step, the equivalent temperature of the motor windings can be estimated using a thermal model. This thermal model considers the motor's copper and iron losses (which can be derived from the input power and operating efficiency), as well as the influence of ambient temperature on heat dissipation. Equivalent Temperature Calculate using the following formula: in, For ambient temperature, temperature rise Calculated using the thermal resistance model according to the following formula: in, The density of water, It is the acceleration due to gravity. Head (i.e., the height of the water column corresponding to the outlet pressure). This represents the actual output flow rate. For input electrical power and operating efficiency The calculated motor power loss The equivalent thermal resistance from the motor windings to the surrounding environment is determined by the motor specifications or factory thermal characteristic test data. The rate of temperature change is obtained by calculating the change in equivalent temperature over adjacent sampling periods and then taking the moving average.

[0030] S40. When the operating efficiency shows a downward trend and the downward trend reaches a preset efficiency decline condition, a first warning signal is triggered. When the temperature change rate shows an upward trend and the upward trend reaches a preset temperature rise rate increase condition, a second warning signal is triggered.

[0031] In this step, the system simultaneously performs efficiency trend analysis and temperature rise rate trend analysis in a dual-channel parallel manner. In the efficiency analysis channel, the linear regression slope is calculated using a sliding window method on continuously collected operating efficiency data. When the slope is consistently negative and its absolute value exceeds a set threshold for a preset number of days, a first warning signal is triggered. This signal indicates that the pump's operating efficiency is showing a continuous downward trend, possibly caused by factors such as increased hydraulic resistance due to scale buildup in the pipes or reduced hydraulic efficiency due to long-term impeller wear. In the temperature rise analysis channel, the continuously estimated rate of change in motor winding temperature is also analyzed using a sliding window. When the temperature rise rate slope is consistently positive and exceeds a set threshold for a preset number of days, a second warning signal is triggered. This signal indicates that the internal heat load of the motor is showing a continuous accumulation trend, possibly caused by factors such as the motor operating under slight overload conditions for a long time or deteriorating heat dissipation due to dust accumulation in the motor's ventilation and cooling pathways. The warning thresholds and processing cycles for the two trend analyses can be configured independently to adapt to different sensitivity requirements for efficiency and temperature rise in various industrial scenarios.

[0032] S50. Based on the first or second warning signal and the cooling requirements of the production line, issue a warning and adjust the operating status of the water pump.

[0033] In this step, when a warning signal is received, the response level is adjusted according to the production line load level and the duration of the warning. The warning information is sent to the maintenance personnel through the audible and visual alarm device, and if necessary, a frequency adjustment command is sent to the frequency converter to reduce the water pump operating frequency, thereby reducing the motor load.

[0034] In the above embodiment, the technical solution establishes a pressure-flow characteristic relationship by real-time acquisition of the input power, outlet pressure, and ambient temperature of the water pump motor, to estimate the actual output flow and calculate the operating efficiency. At the same time, it estimates the equivalent temperature of the motor windings and calculates the rate of temperature change. Then, it triggers an early warning and dynamically adjusts the water pump operating status based on the dual conditions of efficiency decrease and temperature rise rate increase. This achieves a complete closed loop from hydraulic performance monitoring and heat load assessment to early warning response, effectively solving the problem that traditional control systems cannot detect insufficient actual cooling flow and heat load accumulation inside the motor by relying solely on pressure readings, thus avoiding sudden motor burnout and unexpected production line shutdowns.

[0035] In one possible design, Figure 2 This is a flowchart illustrating step S10, pressure sensor zero-point drift correction, according to an exemplary embodiment. (Refer to the attached diagram.) Figure 2 Before acquiring the outlet pressure in real time in step S10, pressure sensor zero-point drift correction is also included: S11. After the water pump motor is in a stopped state and continues for a preset time, read the report value of the pressure sensor as the zero point reading.

[0036] In this step, after the water pump motor stops and remains off for a preset period of time, the water pressure in the pipeline system will tend to reach a stable static pressure value. At this time, the output of the pressure sensor should theoretically be equal to this static pressure value. However, due to factors such as temperature drift and aging, the actual output of the sensor may deviate from the true value. Therefore, it is necessary to read the sensor report value at this time as the zero-point reading for subsequent correction calculations.

[0037] S12. Compare the zero-point reading with the expected true static pressure value to calculate the zero-point drift.

[0038] In this step, the actual static pressure value can be calculated based on the elevation difference of the pump installation location and the pipeline layout, or it can be obtained on-site by measuring with a high-precision standard pressure gauge during pump shutdown. Zero-point drift. Calculate using the following formula: in, For zero-point reading, This represents the expected actual static pressure value.

[0039] S13. After the outlet pressure is collected in real time, the zero-point drift is subtracted to obtain the corrected pressure value, and the corrected pressure value is used for the estimation of the actual output flow and the calculation of operating efficiency.

[0040] In this step: in, For real-time collection of outlet pressure, The corrected pressure value replaces the original collected value and is used for flow estimation and efficiency calculation in subsequent step S20.

[0041] In the above embodiment, the zero-point drift is calculated by reading the zero-point reading of the pressure sensor during the water pump shutdown and comparing it with the expected true static pressure value. The drift is then subtracted during real-time acquisition for correction, eliminating measurement deviations caused by factors such as temperature drift and aging during long-term operation of the pressure sensor. This ensures the accuracy of subsequent flow estimation and efficiency calculation, making early warning judgments more reliable.

[0042] In one example, in the circulating cooling water pump room of a chemical plant, the cooling water circulation system is equipped with a centrifugal water pump with a rated power of 315kW, supplying circulating cooling water to the cooling pipes of the injection molding machines in the workshop. During monthly inspections, maintenance personnel performed a sensor zero-point drift calibration procedure: the water pump motor was stopped for 30 minutes until the pipeline pressure was fully stable, and the pressure sensor report value was read as 0.52MPa. The expected true static pressure value, calculated based on the elevation difference between the water pump installation location and the highest point of the system, was 0.50MPa, resulting in a zero-point drift of 0.02MPa. After calibration, the system resumed operation. When the real-time outlet pressure was 0.78MPa, the system automatically subtracted the zero-point drift to obtain a corrected pressure value of 0.76MPa. This corrected value was used in the subsequent flow estimation step S20, effectively avoiding flow estimation errors caused by long-term sensor drift.

[0043] In one possible design, Figure 3 This is a flowchart illustrating the triggering of the efficiency degradation condition in step S40 according to an exemplary embodiment. (Refer to the attached diagram.) Figure 3 The step of triggering the first warning signal in step S40 includes: S401. Periodically collect operational efficiency data to form an efficiency data sequence, and perform trend analysis on the efficiency data sequence to obtain efficiency change trend values.

[0044] In this step, a daily data collection period is used as the data collection cycle. The average efficiency within that cycle is calculated as the representative efficiency value for that cycle. Efficiency representative values ​​are collected continuously for several cycles to form an efficiency data sequence. A linear regression method is then used to analyze the trend of the efficiency data sequence, with time as the independent variable and the efficiency representative value as the dependent variable. The slope of the linear regression is then fitted as the trend value of efficiency change.

[0045] S402. When the efficiency change trend value is continuously lower than the preset efficiency decline threshold, it is determined that the operating efficiency is continuously declining, and the first warning signal is triggered.

[0046] In this step, the efficiency trend value is compared with a preset efficiency decline threshold. When the slope remains negative and the absolute value exceeds the threshold for a preset number of days, it is determined that the operating efficiency is continuously declining, triggering the first warning signal.

[0047] In the technical solution of the above embodiments, by using linear regression trend analysis instead of single-point judgment to detect the continuous downward trend of efficiency, short-term fluctuation noise can be effectively filtered out, the long-term degradation direction of efficiency can be accurately identified, and false warnings can be avoided due to occasional changes in operating conditions.

[0048] In one example, in the circulating water system of the painting workshop in an automotive parts factory, a 250kW centrifugal water pump supplies circulating cooling water to the electrophoretic coating line and the cooling pipes of the painting robot. The system continuously collected operating efficiency data for 30 days. The daily representative operating efficiency value gradually decreased from 78.2% to 75.1%, and the maintenance engineer observed this slow downward trend through the system interface. Linear regression analysis was performed on these 30 data points, resulting in a regression slope of -0.105% / day. The preset efficiency decline threshold was -0.05% / day. When the slope was below this threshold for 7 consecutive days, the system automatically determined that the operating efficiency was continuously declining and triggered the first warning signal, indicating to the maintenance personnel that the water pump may have scale buildup or impeller wear problems.

[0049] In one possible design, Figure 4 This is a flowchart illustrating the triggering of the temperature rise rate condition in step S40 according to an exemplary embodiment. (Refer to the attached diagram.) Figure 4 The step of triggering the second warning signal in step S40 includes: S403. After smoothing the temperature change rate, periodically collect data to form a temperature data sequence. Perform time difference calculation on the temperature data sequence to obtain the temperature change at each time point, and take the average value of each temperature change to obtain the temperature change rate.

[0050] In this step, the estimated equivalent temperature sequence of the motor windings is first smoothed using a moving average filter, with a window length of 5 sampling periods. Using one hour as a sampling period, the time difference of the smoothed temperature sequence is calculated, as shown in the following formula: This allows us to obtain the temperature change at each time point. Then, we take the average of several consecutive temperature changes to obtain the rate of temperature change.

[0051] S404. Perform trend analysis on the temperature change rate to obtain the temperature rise rate change trend value. When the temperature rise rate change trend value is continuously higher than the preset temperature rise rate increase threshold, it is determined that the temperature change rate is continuously rising, and a second warning signal is triggered.

[0052] In this step, the linear regression method is also used to analyze the trend of temperature change rate. When the temperature rise rate trend value is continuously higher than the preset temperature rise rate threshold, it is determined that the temperature change rate is continuously rising, triggering the second warning signal.

[0053] In the technical solution of the above embodiments, by smoothing and differentially processing the temperature change rate and then performing trend analysis, a meaningful temperature rise acceleration trend can be extracted from the slowly changing temperature signal, which makes up for the problem that traditional temperature threshold protection can only respond to overheating that has already occurred and cannot predict temperature rise acceleration.

[0054] In one example, in the circulating water system of the aforementioned automotive parts factory, after the first warning signal is triggered, the system simultaneously monitors the temperature rise rate of the motor windings. The smoothed equivalent temperature sequence of the motor windings is 225.0℃, 225.3℃, 225.8℃, 226.5℃, 227.4℃, and 228.5℃. The temperature changes calculated using differential methods are 0.3℃ / h, 0.5℃ / h, 0.7℃ / h, 0.9℃ / h, and 1.1℃ / h, respectively. The average of the three most recent changes is taken as 0.9℃ / h. After collecting temperature change rate data for 14 consecutive days, the linear regression slope is +0.032℃ / h / day. When the slope is higher than the threshold of +0.02℃ / h / day for five consecutive days, the system triggers a second warning signal. The warning message indicates that the temperature rise rate of the motor windings is accelerating, and it is recommended to immediately arrange a shutdown for maintenance to clean the scale in the pipes.

[0055] In one possible design, Figure 5 This is a flowchart illustrating the early warning response control in step S50 according to an exemplary embodiment. (Refer to the attached document.) Figure 5 Step S50 includes: S501. When the first warning signal or the second warning signal is received, obtain the load level of the production line and the duration of the current warning signal.

[0056] In this step, the production line load level can be obtained in real time from the production management system, typically categorized into three levels: low load, medium load, and high load. The duration of the warning signal begins counting from the moment it is first triggered.

[0057] S502. Adjust the warning response level according to the load level and the duration. When the load level is higher than the preset load threshold or the duration exceeds the preset time threshold, send a frequency adjustment command to the frequency converter of the water pump to reduce the operating frequency of the water pump.

[0058] In this step, the early warning response level is divided into three levels: Level 1 warning (only audible and visual alerts, no frequency adjustment), Level 2 warning (reducing the water pump operating frequency by 5%), and Level 3 warning (reducing the water pump operating frequency by 10% and notifying maintenance personnel to arrive on site). When the load level is higher than the preset load threshold or the warning duration exceeds the preset time threshold, the response level is upgraded.

[0059] In the above embodiment, the response level is dynamically adjusted by combining the actual load level of the production line and the duration of the warning, which avoids the problems of insufficient cooling due to excessive frequency reduction during high load periods and continuous risk accumulation due to insufficient response during low load periods, thus achieving a balance between protection and production.

[0060] In one possible design, when the first warning signal is triggered, step S40 also includes a joint determination: S405. When the first warning signal is triggered, further detect whether the rate of temperature change is increasing.

[0061] In this step, after the first warning signal (efficiency decline) has been triggered, it is further checked whether the temperature rise rate increases synchronously in order to determine whether the efficiency decline and the temperature rise acceleration originate from the same root cause.

[0062] S406. If the rate of temperature change shows an upward trend and reaches the condition of the rate of temperature rise, it is determined that there is heat load accumulation inside the motor, and the warning information of the first warning signal indicates the cause of motor overload.

[0063] In this step, when efficiency decreases and temperature rises simultaneously, it means that the decrease in efficiency and the acceleration of temperature rise of the water pump motor are due to the same root cause—the increase in system resistance caused by scale accumulation, which increases the motor load. At this time, the warning message clearly indicates that the motor is overloaded.

[0064] S407. If the rate of temperature change does not show an upward trend or does not reach the condition for the rate of temperature rise, it is determined that the heat load is not accumulated inside the motor, and the second warning signal is issued. The warning information of the second warning signal indicates the cause of non-motor overload.

[0065] In this step, if only the efficiency decreases but the temperature rise does not accelerate, it means that the efficiency decrease may be due to other factors, such as pump impeller wear or seal leakage. At this time, the warning information indicates that the cause is not motor overload, guiding maintenance personnel to check for hydraulic problems.

[0066] In the above embodiment, the technical solution distinguishes between motor overload faults and non-motor overload faults by jointly determining the efficiency reduction signal and the temperature rise signal, providing maintenance personnel with more accurate fault location information, avoiding blind troubleshooting, and shortening fault handling time.

[0067] In one possible design, the step of issuing a warning in step S50 further includes adaptive adjustment of audio-visual intensity: S503. Obtain the real-time location information of the maintenance personnel, and select the noise level reported by one or more distributed noise sensors closest to the maintenance personnel as the local noise level.

[0068] In this step, the positioning tags worn by maintenance personnel report their location information in real time. Multiple noise sensors deployed in the system are distributed in different areas such as the pump room, power distribution room, and control room. Based on the current location of the maintenance personnel, the readings of the 1 to 3 nearest noise sensors are selected, and their average value is taken as the local noise level.

[0069] S504. Adjust the sound and light intensity of the warning signal according to the local noise level.

[0070] In this step, the audible and visual intensity of the warning signal is adjusted according to the local noise level: when the local noise level is low, the standard audible and visual intensity is used, and when the local noise level is high, the intensity of the audible and visual alarm is increased to ensure that maintenance personnel can notice the warning signal in a timely manner in a noisy industrial environment.

[0071] In the above embodiment, the warning intensity is adaptively adjusted according to the actual noise level of the area where the maintenance personnel are located, thus avoiding the problem that a fixed intensity warning is drowned out in a noisy environment and too harsh in a quiet environment, and ensuring that the warning information can be effectively conveyed.

[0072] In one example, after an early warning signal was issued at the circulating water pump room, the on-duty maintenance personnel were conducting a routine inspection in the power distribution room. The inverters and transformers in the power distribution room generate high background noise during operation. The two distributed noise sensors closest to the maintenance personnel read 72dB and 68dB respectively, and the system took the average of 70dB as the local noise level. Because the local noise level was higher than the preset 60dB benchmark, the system automatically increased the alarm volume from the standard 65dB to 75dB and increased the flashing alarm frequency from 1Hz to 3Hz, ensuring that the maintenance personnel could still promptly perceive the early warning signal and proceed to the pump room to handle the situation despite the high background noise in the power distribution room.

[0073] In summary, the centrifugal water pump operating efficiency and temperature rise trend early warning method provided by this invention collects input power, outlet pressure, and ambient temperature in real time, establishes a pressure-flow characteristic relationship to estimate the actual output flow and calculate the operating efficiency, estimates the equivalent temperature of the motor windings and calculates the temperature change rate, and achieves a complete closed loop from hydraulic performance monitoring and heat load assessment to early warning response through a dual early warning mechanism of efficiency decline and temperature rise rate increase combined with dynamic response control. This effectively solves the problem that traditional control systems cannot detect insufficient actual cooling flow and internal heat load accumulation of the motor by relying solely on pressure readings, thus avoiding sudden motor burnout and unexpected production line shutdowns.

[0074] Example 2 Embodiment 2 of this application provides a centrifugal water pump operating efficiency and temperature rise trend early warning system. Figure 6 This is a block diagram illustrating a centrifugal water pump operating efficiency and temperature rise trend early warning system according to another exemplary embodiment. Figure 6 As shown, the system includes: Data acquisition module 01 is used to collect the input power of the water pump motor, the outlet pressure of the water pump, and the temperature of the water pump operating environment in real time; Efficiency evaluation module 02 is used to establish the characteristic relationship between water pump pressure and flow rate, estimate the actual output flow rate based on the outlet pressure and the characteristic relationship, calculate the output hydraulic power of the water pump based on the actual output flow rate and the outlet pressure, and obtain the operating efficiency of the water pump motor by combining the input electrical power. Temperature rise assessment module 03 is used to estimate the equivalent temperature of the motor winding based on the input power, the operating efficiency and the temperature, and to calculate the temperature change rate of the motor winding based on the change in the equivalent temperature. The early warning triggering module 04 is used to trigger a first early warning signal when the operating efficiency shows a downward trend and the downward trend reaches a preset efficiency decline condition, and to trigger a second early warning signal when the temperature change rate shows an upward trend and the upward trend reaches a preset temperature rise rate increase condition. The response control module 05 is used to issue an early warning and adjust the operating status of the water pump based on the first early warning signal or the second early warning signal and the cooling requirements of the production line.

[0075] The centrifugal water pump operating efficiency and temperature rise trend early warning system provided in Embodiment 2 of the present invention, through the coordinated operation of the data acquisition module 01, efficiency evaluation module 02, temperature rise evaluation module 03, early warning trigger module 04 and response control module 05, realizes the closed-loop management of automatic monitoring, intelligent judgment and dynamic response to the decline in centrifugal water pump operating efficiency and abnormal temperature rise of motor windings. It effectively solves the problem that traditional control systems cannot detect insufficient actual cooling flow and accumulation of internal heat load of motor by relying solely on pressure readings, and avoids sudden burnout of motor and unexpected shutdown of production line.

[0076] This application also provides a computer device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the method described in Embodiment 1 above. Specifically, the computer device may be an industrial control computer, a programmable logic controller (PLC), or an embedded controller. The memory is used to store the computer program and temporary data generated during operation. The processor is responsible for reading and executing the computer program in the memory to drive the computer device to complete the various steps in the above method. The input / output interface is used to connect external devices such as a power sensor for the water pump motor, an outlet pressure sensor, an ambient temperature sensor, and a frequency converter.

[0077] This application also provides a computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the steps of the method described in Embodiment 1 above. Specifically, the computer-readable storage medium can be a non-volatile storage medium such as a solid-state drive, embedded flash memory, or read-only memory. When the system starts up, the processor loads and executes the computer program from the storage medium, thereby realizing automatic monitoring and management of the centrifugal water pump's operating status.

[0078] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for early warning of centrifugal water pump operating efficiency and temperature rise trend, characterized in that, Includes the following steps: Real-time data collection of the pump motor's input power, pump outlet pressure, and ambient temperature. Establish the characteristic relationship between pump pressure and flow rate, estimate the actual output flow rate based on the outlet pressure and the characteristic relationship, calculate the pump output hydraulic power based on the actual output flow rate and the outlet pressure, and obtain the pump motor operating efficiency by combining the input electrical power. The equivalent temperature of the motor windings is estimated based on the input power, the operating efficiency, and the temperature, and the rate of temperature change of the motor windings is calculated based on the change in the equivalent temperature. When the operating efficiency shows a downward trend and the downward trend reaches a preset efficiency decline condition, a first warning signal is triggered; when the temperature change rate shows an upward trend and the upward trend reaches a preset temperature rise rate increase condition, a second warning signal is triggered. Based on the first or second warning signal and the cooling requirements of the production line, an early warning is issued and the operating status of the water pump is adjusted.

2. The method according to claim 1, characterized in that, Before establishing the characteristic relationship between pump pressure and flow rate, the following steps are also included: After the water pump motor is in a stopped state for a preset time, the reported value of the pressure sensor is read as the zero point reading. The zero point reading is compared with the expected real static pressure value to calculate the zero point drift. After the outlet pressure is collected in real time, the zero-point drift is subtracted to obtain the corrected pressure value, which is then used for the estimation of the actual output flow and the calculation of operating efficiency.

3. The method according to claim 1, characterized in that, The step of triggering the first warning signal when the operating efficiency shows a downward trend and the downward trend reaches a preset efficiency decline condition includes: Periodically collect operational efficiency data to form an efficiency data sequence, and perform trend analysis on the efficiency data sequence to obtain efficiency change trend values; When the efficiency change trend value is continuously lower than the preset efficiency decline threshold, it is determined that the operating efficiency is continuously declining, and the first warning signal is triggered.

4. The method according to claim 1, characterized in that, The step of triggering the second warning signal when the rate of temperature change shows an upward trend and the upward trend reaches a preset temperature rise rate condition includes: After smoothing the temperature change rate, periodic data collection is performed to form a temperature data sequence. The temperature data sequence is then subjected to time difference calculation to obtain the temperature change at each time point, and the average value of each temperature change is taken to obtain the temperature change rate. Trend analysis is performed on the temperature change rate to obtain the temperature rise rate change trend value. When the temperature rise rate change trend value is continuously higher than the preset temperature rise rate increase threshold, it is determined that the temperature change rate is continuously rising, triggering a second warning signal.

5. The method according to claim 1, characterized in that, The steps of issuing an early warning and adjusting the operating status of the water pump include: When the first warning signal or the second warning signal is received, the load level of the production line and the duration of the current warning signal are obtained; The warning response level is adjusted according to the load level and the duration. When the load level is higher than the preset load threshold or the duration exceeds the preset time threshold, a frequency adjustment command is sent to the frequency converter of the water pump to reduce the operating frequency of the water pump.

6. The method according to claim 1, characterized in that, When the first warning signal is triggered, further detection is needed to determine whether the rate of temperature change is increasing. If the rate of temperature change shows an upward trend and reaches the condition of the rate of temperature rise, it is determined that there is heat load accumulation inside the motor, and the warning information of the first warning signal indicates the cause of motor overload. If the rate of temperature change does not show an upward trend or does not reach the condition for the rate of temperature rise, it is determined that the cause is not the internal heat load of the motor, and the second warning signal is issued. The warning information of the second warning signal indicates the cause of the non-motor overload.

7. The method according to claim 5, characterized in that, The steps for issuing an early warning also include: Obtain the real-time location information of the maintenance personnel, and select the noise level reported by one or more distributed noise sensors closest to the maintenance personnel as the local noise level; The audible and visual intensity of the warning signal is adjusted according to the local noise level.

8. A centrifugal water pump operating efficiency and temperature rise trend early warning system, characterized in that, The system includes: The data acquisition module is used to collect the input power of the water pump motor, the outlet pressure of the water pump, and the temperature of the water pump operating environment in real time. The efficiency evaluation module is used to establish the characteristic relationship between pump pressure and flow rate, estimate the actual output flow rate based on the outlet pressure and the characteristic relationship, calculate the output hydraulic power of the pump based on the actual output flow rate and the outlet pressure, and obtain the operating efficiency of the pump motor by combining the input electrical power. The temperature rise assessment module is used to estimate the equivalent temperature of the motor windings based on the input power, the operating efficiency, and the temperature, and to calculate the rate of temperature change of the motor windings based on the change in the equivalent temperature. The early warning triggering module is used to trigger a first early warning signal when the operating efficiency shows a downward trend and the downward trend reaches a preset efficiency decline condition, and to trigger a second early warning signal when the temperature change rate shows an upward trend and the upward trend reaches a preset temperature rise rate increase condition. The response control module is used to issue an early warning and adjust the operating status of the water pump based on the first early warning signal or the second early warning signal and the cooling requirements of the production line.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 7.

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