A real-time detection and calculation method of volumetric efficiency based on the temperature difference of three ports of a plunger pump

Abstract

The present invention provides a real-time detection and calculation method of volumetric efficiency based on the temperature difference at three ports of a plunger pump, and belongs to the field of plunger pump status monitoring. It includes three parts, namely: temperature sensor arrangement, signal acquisition and preprocessing, and a method for calculating volumetric efficiency based on the temperature difference at three ports of a plunger pump. The specific process is: the temperature sensors are arranged at special temperature measurement positions at the oil inlet, oil outlet, oil return or shell of the plunger pump to provide real-time data input for calculating volumetric efficiency; a temperature signal conditioning and digital-to-analog conversion device is built to complete data transmission, data that interferes with the calculation of volumetric efficiency is eliminated, and the temperature difference at three ports of the plunger pump is calculated; the volumetric efficiency is calculated based on the temperature difference at three ports of the plunger pump. The present invention utilizes the strong correlation between the temperature difference at three ports of the plunger pump and the volumetric efficiency to establish a real-time mapping relationship between the two, and proposes a real-time detection and calculation method for the volumetric efficiency of the plunger pump by monitoring the temperature signal, which will be helpful for the status monitoring and daily maintenance of the plunger pump.

Description

Technical Field

[0001] This invention provides a method for real-time detection and calculation of volumetric efficiency based on the temperature difference at the three ports of a plunger pump, relating to the field of plunger pump condition monitoring technology, and particularly to a method for real-time detection of the volumetric efficiency of a plunger pump. Background Technology

[0002] Piston pumps are the most common power components in hydraulic systems. After prolonged operation, their volumetric efficiency gradually decreases due to wear and deformation under stress. This results in a reduction in the amount of oil and pressure input to the hydraulic system under the same operating conditions, directly affecting the performance of the actuators. In the design and production of piston pumps, volumetric efficiency testing is a crucial standard for determining pump quality. For reliability and safety reasons, when the volumetric efficiency of a piston pump falls below a certain limit, the pump is considered to have reached the end of its service life and can no longer be used. Furthermore, if the volumetric efficiency status of the piston pump during operation is unclear, subsequent periodic maintenance will lack focus, leading to additional maintenance costs or serious accidents due to untimely repairs. Therefore, it is essential to develop a convenient and reliable method for real-time detection and calculation of piston pump volumetric efficiency.

[0003] As shown in invention patents such as "A Device for Detecting the Volumetric Efficiency of an Oil Pump" (application number CN201810855646.6), "An Online Device for Detecting the Volumetric Efficiency of a Constant Pressure Variable Pump" (application number CN201120305740.8), "A Test System and Method for the Volumetric Efficiency of an Aero-engine Fuel Gear Pump" (application number CN 202210509519.7), and "A Method for Calculating the Design Volumetric Efficiency of a Gear Pump" (application number CN 201910466017.9), most patented methods for calculating volumetric efficiency currently focus on gear pumps. This is because gear pumps have a simple structure, low operating pressure, and a simple testing process, and can generally be tested by installing a flow meter with moving parts. However, most plunger pumps operate in high-pressure, high-flow, and high-power applications, such as aircraft control surfaces, hydraulic press compression, engineering machinery operation, and ship lifting. In these applications, the hydraulic systems bear high pressure and intense vibration, making it unsuitable to install large, moving-part, and low-reliability testing devices such as flow meters. Meanwhile, modifying pipelines or piston pumps to install detection devices with moving parts, such as flow meters, will affect the working performance of the piston pump and hydraulic system, causing additional power loss and reducing equipment safety and reliability.

[0004] The invention patent "Plunger Pump and its Volumetric Efficiency Measurement Method and Plunger Stroke Adjustment Method" (application number CN201310428733.0) describes a method for measuring the volumetric efficiency of a plunger pump that requires shutting down the pump and disassembling it for specialized testing. This method of measuring the volumetric efficiency of the plunger pump after disassembly affects production and incurs additional costs. Because the airtightness of the testing system differs from that of the actual hydraulic system in operation, the volumetric efficiency measured by this method tends to be higher. Furthermore, it cannot achieve real-time online monitoring of the plunger pump, making it impossible to determine the pump's operating status in real time and thus hindering the timely detection or prevention of malfunctions. With long-term operation of the plunger pump, the aging of the testing equipment leads to a gradual decrease in testing accuracy, and replacing the testing equipment requires additional costs.

[0005] Therefore, current methods cannot effectively achieve real-time monitoring of the volumetric efficiency of plunger pumps under complex operating conditions. It is essential to invent a real-time monitoring and easily maintained method for detecting the volumetric efficiency of plunger pumps. Through engineering practice, the inventors discovered a potential correlation between changes in the internal temperature of the plunger pump and its volumetric efficiency; the temperature difference between the inlet, outlet, and return port (or casing) is strongly correlated with volumetric efficiency. Among various sensing devices, temperature sensors, with their lack of moving parts, small size, and light weight, are highly suitable for monitoring the condition of plunger pumps. Therefore, a special method for calculating volumetric efficiency based on the real-time detection of the temperature difference between the three ports of the plunger pump is proposed. Summary of the Invention

[0006] (I) Purpose of the Invention

[0007] The purpose of this invention is to provide a real-time detection and calculation method for the volumetric efficiency of a plunger pump, addressing the technical problem that the volumetric efficiency of plunger pumps cannot be detected by traditional flow meters under high pressure, high flow rate, and high power operating conditions. This invention relates to a real-time detection and calculation method for volumetric efficiency based on the three-port temperature difference of a plunger pump, overcoming the problem that the high pressure and strong vibration of hydraulic systems prevent the installation of large-volume detection devices with moving parts on plunger pumps. Based on the strong correlation between the three-port temperature difference and volumetric efficiency, this invention proposes a special arrangement and detection method for the plunger pump temperature sensor, establishing a method for real-time detection and calculation of volumetric efficiency using the three-port temperature difference as data input. This provides convenient conditions for the condition monitoring and daily maintenance of plunger pumps.

[0008] (II) Technical Solution

[0009] The technical solution and specific implementation process involved in this invention are as follows:

[0010] The technical solution of this invention is a real-time detection and calculation method for volumetric efficiency based on the temperature difference of the three ports of a plunger pump, including: the arrangement of temperature sensors for detecting and calculating the volumetric efficiency of the plunger pump, the acquisition and preprocessing of temperature signals, and a method for calculating volumetric efficiency based on the temperature difference of the three ports of the plunger pump.

[0011] For example, the plunger pump is driven by a three-phase asynchronous motor and connected via a coupling with a speed and torque sensor. Temperature sensors are installed at the inlet, outlet, and return port (or housing) of the plunger pump. The arrangement of the temperature sensors depends on the specific pump structure, and their purpose is to measure real-time temperature data of typical parts of the plunger pump, providing a data basis for subsequent temperature signal processing and volumetric efficiency calculation.

[0012] The signal collected by the temperature sensor is connected to the main control box via a cable and processed by the signal conditioning and digital-to-analog conversion device.

[0013] The main control box is externally connected to a computer, which uses a special algorithm to clean the converted data, removing data that interferes with the calculation of the plunger pump's volumetric efficiency, and completing signal acquisition. Data cleaning plays a special and irreplaceable role in this process, specifically proposed due to the unique characteristics of this volumetric efficiency calculation method. This is because the special process of removing temperature-adverse sample data (not specifically referring to data outliers) has a significant impact on the final volumetric efficiency calculation and prediction.

[0014] The final real-time temperature data collected for the oil inlet, oil outlet, and oil return port (or casing) are as follows: T in T out T re ;

[0015] For temperature signal T in T out T re Perform the following calculations:

[0016] △T1=T re -T in

[0017] △T2=T out -T in

[0018] △T3=T re -T out

[0019] The temperature difference between the return oil and the inlet oil is ΔT1, the temperature difference between the outlet oil and the inlet oil is ΔT2, and the temperature difference between the return oil and the outlet oil is ΔT3.

[0020] Based on the three-port temperature difference data of the plunger pump, this paper establishes the three-port temperature difference-volume efficiency η of the plunger pump using different methods such as the plunger pump thermal failure principle, machine learning, and regression analysis. vp The predictive model improves the accuracy of calculating the predicted volumetric efficiency, ultimately yielding the plunger pump's volumetric efficiency η. vp The calculation formula is in the following form:

[0021] η vp =f(ΔT1,ΔT2,ΔT3)

[0022] For example, using the simplest linear regression analysis, a formula can be established using the inlet-outlet temperature difference ΔT1, the outlet-outlet temperature difference ΔT2, and the outlet-return temperature difference ΔT3:

[0023] η vpi =b0+b1ΔT1+b2ΔT2+b3ΔT3+μ i

[0024] Then, the least squares method is used to estimate the parameters, and the solutions for coefficients b0, b1, b2, and b3 are obtained.

[0025] Then, the standard error is calculated, and the accuracy of the calculation is not lower than the required limit for the actual volumetric efficiency;

[0026] Finally, based on the three-port temperature difference of the plunger pump and its volumetric efficiency η... vp Using a predictive model and real-time data input, the real-time volumetric efficiency η of the plunger pump is calculated. vp The real-time volumetric efficiency prediction curve of the plunger pump was obtained.

[0027] (III) Beneficial Effects of the Invention

[0028] This invention provides a method for real-time detection and calculation of the volumetric efficiency of a plunger pump under conditions where detection devices with moving parts, large size, and low reliability are limited. Based on the strong correlation between the temperature difference at the three ports of a plunger pump and its volumetric efficiency, and utilizing the advantages of temperature sensors—lightweight, no moving parts, small size, and high reliability—this invention proposes a convenient method for real-time detection and calculation of volumetric efficiency based on the temperature difference at the three ports of a plunger pump, addressing three aspects: temperature sensor arrangement, data acquisition and processing, and volumetric efficiency calculation.

[0029] The present invention relates to a method for predicting the volumetric efficiency of a plunger pump by calculating the temperature difference at the three ports of the plunger pump. This method can use real-time temperature data to provide feedback on the current volumetric efficiency of the plunger pump, show the real-time working status of the plunger pump, reduce the daily maintenance costs of the plunger pump, and improve the safety and reliability of the plunger pump. Attached Figure Description

[0030] To more clearly illustrate the implementation process of this method, the accompanying drawings are summarized below. Obviously, these drawings are merely for illustrative purposes. Those skilled in the art can easily develop other forms of drawings and specific implementation schemes for calculating the volumetric efficiency of a plunger pump using temperature signal detection in different scenarios without any creative effort.

[0031] Figure 1 The flowchart shows the implementation of the plunger pump volumetric efficiency testing scheme based on this method.

[0032] Figure 2 A schematic diagram of the sensor arrangement for calculating the volumetric efficiency of a plunger pump based on temperature signal detection;

[0033] Figure 3 Flowchart of data acquisition and calculation process for the three-port temperature of a plunger pump;

[0034] Figure 4 The flowchart shows the method for calculating the volumetric efficiency based on the temperature difference at the three ports of a plunger pump.

[0035] Figure 5 A schematic diagram showing the real-time display curve of temperature difference signal and volumetric efficiency;

[0036] Appendix Figure 2 The list of components represented by each number is as follows:

[0037] 1-Three-phase asynchronous motor, 2-Coupling with torque and speed measurement functions, 3-Plunger pump, 4-Inlet temperature sensor, 5-Outlet temperature sensor, 6-Return port / housing temperature sensor, 7-Oil tank. Detailed Implementation

[0038] The specific embodiments of the present invention will now be described in their entirety with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the method of the present invention and do not represent the entire implementation process. Other embodiments based on the method in this embodiment, without creative effort, are all within the protection scope of the present invention.

[0039] Example:

[0040] like Figure 2 , Figure 3 As shown, the specific implementation of the real-time detection and calculation method for volumetric efficiency based on the three-port temperature difference of a plunger pump according to the present invention includes: sensor arrangement for detecting and calculating the volumetric efficiency of a plunger pump based on temperature signals, temperature signal acquisition and preprocessing, and volumetric efficiency calculation based on the three-port temperature difference of the plunger pump.

[0041] like Figure 2As shown, the plunger pump 3 is driven by a three-phase asynchronous motor 1 and connected by a coupling 2 with a speed and torque sensor. Temperature sensors 4-6 are installed at the oil inlet, oil outlet, and oil return port (or housing) of the plunger pump, respectively.

[0042] like Figure 3 As shown, the signals collected by the temperature sensors 4-6 are connected to the main control box via cables and undergo signal conditioning and digital-to-analog conversion.

[0043] like Figure 3 As shown, the main control box is externally connected to a computer, which uses a special algorithm to clean the converted data and remove data that interferes with the calculation of the plunger pump volumetric efficiency.

[0044] like Figure 4 As shown, the final real-time temperature data collected for the oil inlet, oil outlet, and oil return port (or casing) are as follows: T in T out T re ;

[0045] like Figure 4 As shown, for the temperature signal T in T out T re Perform the following calculations:

[0046] △T1=T re -T in

[0047] △T2=T out -T in

[0048] △T3=T re -T out

[0049] The temperature difference between the return oil and the inlet oil is ΔT1, the temperature difference between the outlet oil and the inlet oil is ΔT2, and the temperature difference between the return oil and the outlet oil is ΔT3.

[0050] like Figure 4 As shown, based on the three-port temperature difference data of the plunger pump, and utilizing different methods such as the plunger pump thermal failure principle, machine learning, and regression analysis, a three-port temperature difference-volume efficiency η of the plunger pump is established. vp The predictive model improves the accuracy of calculating the predicted volumetric efficiency, thus obtaining the volumetric efficiency η of the plunger pump. vp The calculation formula is in the following form:

[0051] η vp =f(ΔT1,ΔT2,ΔT3)

[0052] For example, using the simplest linear regression analysis, a formula can be established using the inlet-outlet temperature difference ΔT1, the outlet-outlet temperature difference ΔT2, and the outlet-return temperature difference ΔT3:

[0053] η vpi =b0+b1ΔT1+b2ΔT2+b3ΔT3+μ i

[0054] Then, the least squares method is used to estimate the parameters, and the solutions for coefficients b0, b1, b2, and b3 are obtained.

[0055] Then, the standard error is calculated, and the accuracy of the calculation is not lower than the required limit for the actual volumetric efficiency;

[0056] Based on the three-port temperature difference-volume efficiency η of the plunger pump vp Using a predictive model and real-time data input, the real-time volumetric efficiency η of the plunger pump is calculated. vp ;

[0057] like Figure 5 As shown, the final predicted change curve of the real-time volumetric efficiency of the plunger pump is obtained.

[0058] In this embodiment, the real-time volumetric efficiency η can be calculated based on the temperature difference data from the three ports. vp The temperature curve is used to achieve real-time detection and calculation of the plunger pump's volumetric efficiency. If the temperature difference between the three ports is too large, the calculated actual volumetric efficiency of the plunger pump will be too low and exceed a certain range, indicating that the plunger pump has failed. This allows for real-time monitoring of the plunger pump's operating status. Figure 5 The curves showing the real-time results of temperature difference signal and volumetric efficiency are schematic diagrams drawn for illustrative and clear purposes only, and do not represent the specific temperature difference and volumetric efficiency changes of the plunger pump.

[0059] In the descriptions of "Embodiments" and "Examples" in this specification, the methods, processes, and implementations described are not necessarily the same actual examples. Furthermore, the methods, processes, and implementations described in the "Embodiments" or "Examples" of this invention can be combined in any one or more embodiments or examples.

[0060] The embodiments described above are merely illustrative of the method of the present invention and do not provide detailed implementation details, nor do they limit the invention to specific implementation methods. The embodiments involved in this specification are intended to better explain the principles and application process of the method of the present invention, so that those skilled in the art can better understand and utilize the present invention.

[0061] This invention is limited only by the claims and their full scope and equivalents.

Claims

1. A real-time detection and calculation method for volumetric efficiency based on the temperature difference of three ports of a plunger pump, characterized in that: include: The sensor arrangement for calculating the volumetric efficiency of a plunger pump based on the detection of temperature signals, the temperature signal collection and processing process, and a volumetric efficiency calculation method based on the temperature difference of three ports of a plunger pump are described in the following specific steps: Step 1: The plunger pump (3) is driven by a three-phase asynchronous motor (1) and connected via a coupling (2) with a speed torque sensor. The oil inlet, oil outlet and oil return port of the plunger pump are respectively equipped with temperature sensors (4-6); Step 2: The signal collected by the temperature sensor (4-6) is processed by a signal conditioning and digital-to-analog conversion device; Step 3: Use a special algorithm to clean the converted data, remove the data that interferes with the calculation of the volumetric efficiency of the plunger pump, and obtain the return oil-inlet temperature difference △T1, the outlet oil-inlet temperature difference △T2, and the return oil-outlet temperature difference △T3; Step 4: Based on the temperature difference data of the three ports of the plunger pump, the plunger pump three-port temperature difference-volume efficiency η is established by using the plunger pump thermal failure principle, machine learning and regression analysis. vp Predictive models; Step 5: Based on the temperature difference between the three ports of the plunger pump - volumetric efficiency η vp The prediction model and real-time temperature data are input to calculate the real-time volumetric efficiency η of the plunger pump. vp .

2. The method for real-time volumetric efficiency detection and calculation based on the temperature difference of three ports of a plunger pump according to claim 1, characterized in that: In steps 1-5, the type of sensor selected for detecting and calculating the volumetric efficiency is a temperature sensor, which is arranged at the oil inlet, oil outlet, and oil return of the plunger pump. Its purpose is to measure the real-time temperature of typical parts of the plunger pump as the data basis for calculating the real-time volumetric efficiency.

3. The method for real-time detection and calculation of volumetric efficiency based on the temperature difference of three ports of a plunger pump according to claim 1, characterized in that: In steps 4 and 5, the volumetric efficiency is calculated based on the temperature difference at the three ports of the plunger pump, and the plunger pump three-port temperature difference-volume efficiency η is established using the plunger pump thermal failure principle, machine learning, and regression analysis methods. vp The prediction model does not refer to a single method, but includes the random combination of the detailed methods in these three categories, as well as the overall idea of ​​using temperature difference data to calculate the predicted volumetric efficiency.

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