Plunger pump volumetric efficiency prediction method based on oil inlet temperature, oil return port temperature and load pressure

Abstract

The invention provides a plunger pump volumetric efficiency prediction method based on temperature and load pressure of an oil inlet and an oil return port, which belongs to the field of plunger pump state detection and mainly comprises the following steps: acquiring and processing data of temperature and pressure sensors; and calculating the volumetric efficiency based on the oil inlet temperature, the oil return port temperature and the load pressure. The method specifically comprises the steps that temperature sensors are arranged at an oil inlet and an oil return opening of the plunger pump, a pressure sensor is arranged at an outlet of the plunger pump, and real-time data input is provided for calculating the volume efficiency; a temperature signal conditioning and digital-to-analog conversion device is built, data transmission is completed, and data having interference on calculation of the volumetric efficiency is eliminated; and calculating the volumetric efficiency based on the temperatures of the oil inlet and the oil return port of the plunger pump and the load pressure. According to the method, the high correlation between the temperatures of the oil inlet and the oil return opening of the plunger pump, the load pressure and the volume efficiency is utilized, the real-time mapping relation between the temperatures and the volume efficiency is established, the method for achieving real-time detection and calculation of the volume efficiency of the plunger pump by monitoring temperature signals is provided, and state monitoring and daily maintenance of the plunger pump are facilitated.

Description

Technical Field

[0001] The invention belongs to the field of plunger pump state monitoring and relates to a method for predicting the volumetric efficiency of a plunger pump based on the temperatures of an oil inlet and an oil return port and load pressure. Background Art

[0002] Most current transportation vehicles rely on hydraulic systems, which are widely used due to their fast dynamic response, high output power, and self-lubrication. As the heart of transportation vehicles, hydraulic systems directly impact the reliability and safety of equipment. The plunger pump, providing power for the hydraulic system, is the core of the hydraulic system. However, after long-term operation, due to wear and deformation under stress, the leakage flow between the friction pairs within the plunger pump increases, reducing volumetric efficiency and causing higher volumetric losses. The lost work is converted into heat energy that accumulates within the plunger pump, causing severe temperature rise and affecting the operational stability and reliability of the plunger pump.

[0003] Existing methods for monitoring the volumetric efficiency of plunger pumps are unable to effectively achieve real-time monitoring. This is partly because the working environment of plunger pumps is generally high pressure, high flow, and high power, making it difficult to install devices such as flow meters that have relatively low reliability and affect the operation of the plunger pump. Furthermore, some detection methods are limited by the detection equipment and require disassembly and inspection after shutdown. This also results in certain errors in the assessment of the volumetric efficiency of the plunger pump. However, real-time monitoring of the volumetric efficiency of the plunger pump is crucial. For reliability and safety reasons, when the volumetric efficiency of a plunger pump falls below a certain limit, it is considered that the pump can no longer be used. If the volumetric efficiency status of the plunger pump during operation is unclear, subsequent regular maintenance will be untargeted, resulting in additional maintenance costs or serious accidents due to untimely maintenance. Therefore, it is very necessary to invent a method for detecting the volumetric efficiency of a plunger pump that allows real-time monitoring and is easy to maintain. There is a potential connection between the changes in the internal temperature and load pressure of the plunger pump and the volumetric efficiency. Its oil inlet temperature, oil return port temperature and load pressure have a strong correlation with the volumetric efficiency. Therefore, a method for predicting the volumetric efficiency of the plunger pump based on the oil inlet, oil return port temperature and load pressure is proposed. Summary of the Invention

[0004] (1) Purpose of the invention

[0005] The purpose of the present invention is to address the problem that the volumetric efficiency of the plunger pump cannot be monitored in real time, and to propose a method for real-time detection and calculation of the volumetric efficiency of the plunger pump, so as to solve the technical problem that the volumetric efficiency of the plunger pump cannot be detected by a traditional flow meter under high-pressure, large-flow, and high-power working conditions. The present invention relates to a method for predicting the volumetric efficiency of a plunger pump based on the temperature of the oil inlet and return port and the load pressure, which can overcome the above-mentioned problem and achieve real-time monitoring and evaluation. Based on the strong correlation between the temperature of the oil inlet and return port of the plunger pump, the load pressure and the volumetric efficiency, the present invention proposes a special arrangement and detection method for the plunger pump temperature sensor, and establishes a method for real-time detection and calculation of the volumetric efficiency using the temperature of the oil inlet and return port of the plunger pump and the load pressure as data input, which provides convenient conditions for the status monitoring and daily maintenance of the plunger pump.

[0006] (2) Technical solution

[0007] The technical solution of the present invention is: a method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and oil return port temperatures and load pressure, including the following: collecting and processing temperature and pressure sensor data; and calculating the volumetric efficiency based on the oil inlet and oil return port temperatures and load pressure. The specific steps are:

[0008] Step 1: 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 respectively installed at the oil inlet and oil return ports of the plunger pump, and a pressure sensor is installed at the outlet pipeline of the plunger pump. The specific installation position is related to the pump body structure of the plunger pump. The sensors are installed as needed to measure the real-time temperature data of the oil in the oil inlet and oil return pipelines of the plunger pump and the real-time pressure data of the plunger pump outlet load, providing a data basis for subsequent signal processing and volumetric efficiency calculation.

[0009] Step 2: The signals collected by the temperature sensor and pressure sensor are processed by signal conditioning and digital-to-analog conversion devices, and the sensor data is collected into the computer through the A / I port to achieve real-time data transmission;

[0010] Step 3: The data collected by the computer is cleaned by a special algorithm to remove the data that interferes with the calculation of the volumetric efficiency of the plunger pump to complete the signal collection. Data cleaning is special and plays an irreplaceable role in this process. Due to the strong correlation between the oil inlet and return port temperatures and the load pressure on the volumetric efficiency calculation, bad sample data will greatly affect the prediction of volumetric efficiency and requires intelligent elimination, such as cleaning sensor system errors, digital-to-analog conversion errors, etc. The data anomalies caused by the error are finally collected. i , oil return temperature T r , load pressure P o ;

[0011] Step 4: Based on the plunger pump's oil inlet and return port temperature and load pressure data, and utilizing the plunger pump's thermal failure principle, develop an intelligent algorithm and build a model to predict the impact of the plunger pump's oil inlet and return port temperature and load pressure on volumetric efficiency.

[0012] Step 5: Based on the plunger pump oil inlet, oil return port temperature and load pressure-volume efficiency η v Prediction model, processes real-time temperature and pressure data, and calculates the real-time volumetric efficiency η of the plunger pump v , the real-time volumetric efficiency prediction change curve of the plunger pump is obtained, and then the model parameters are corrected according to the prediction error until the prediction requirements are met.

[0013] (3) Beneficial Effects of the Invention

[0014] The present invention provides a method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and return port temperatures and load pressure. Starting from the real-time evaluation of the plunger pump's volumetric efficiency, and based on the strong correlation between the oil inlet and return port temperatures, load pressure, and volumetric efficiency, an intelligent prediction algorithm is developed and verified. The effectiveness of this method is verified through simulation. This method solves the current problem of unclear operating patterns and unknown status of plunger pumps, realizes the prediction of the plunger pump's volumetric efficiency, characterizes its operating status in real time, ensures the high-efficiency operation of the plunger pump, and improves the operational reliability and safety of the plunger pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The invention provides a method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and oil return port temperatures and load pressure.

[0016] Figure 2 The figure is a schematic diagram of the arrangement of the temperature sensor and the pressure sensor of a certain type of plunger pump in an embodiment of the present invention.

[0017] Figure 3 Schematic diagram of plunger pump temperature and pressure signal processing and conversion in an embodiment of the present invention.

[0018] Figure 4 Schematic diagram of a method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and oil return port temperatures and load pressure in an embodiment of the present invention.

[0019] Figure 5 Schematic diagram of the volumetric efficiency prediction result and actual result curve in the embodiment of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to a simulation example. The implementation method described in this embodiment is only a special case of the method of the present invention and does not represent the entire implementation process.

[0021] This example uses a certain model of plunger pump as the research object. The system uses a motor to drive the plunger pump's main shaft to provide torque and speed, and a torque-speed meter detects the input power. The system also uses a cooling system to cool the outlet and return oil, maintaining the oil tank temperature within a constant range to minimize the impact on volumetric efficiency prediction. Figure 1 This is a flow chart of the method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and return port temperatures and load pressure of the present invention. The main contents include: collecting and processing data from temperature and pressure sensors; calculating the volumetric efficiency based on the oil inlet and return port temperatures and load pressure. The specific implementation steps are as follows:

[0022] Step 1: Install temperature sensors at the oil inlet and return port of the plunger pump respectively, and install a pressure sensor at the outlet pipeline of the plunger pump to measure the real-time temperature data of the oil in the oil inlet and return pipelines of the plunger pump and the real-time pressure data of the plunger pump outlet load, providing data basis for subsequent signal processing and volumetric efficiency calculation. The specific installation locations are as follows: Figure 2 As shown, the outlet load of the plunger pump is changed by adjusting the proportional valve;

[0023] Step 2: The signals collected by the temperature sensor and pressure sensor are all processed through signal conditioning and digital-to-analog conversion devices, and the sensor data is collected into the computer through the A / I port, and memory is allocated for real-time data transmission, such as Figure 3 As shown;

[0024] Step 3: The data is then cleaned by the computer's internal algorithm to remove data that interferes with the calculation of the plunger pump's volumetric efficiency, such as Figure 3 As shown in the figure. Due to the strong correlation between the oil inlet and return port temperatures and the load pressure on the volumetric efficiency calculation, bad sample data will greatly affect the prediction of volumetric efficiency and need to be intelligently eliminated, such as data anomalies caused by cleaning sensor system errors, digital-to-analog conversion errors, etc., and finally the oil inlet temperature T is collected. i , oil return temperature T r , load pressure P o ;

[0025] Step 4: Based on the plunger pump oil inlet and return port temperature and load pressure data, and using the plunger pump thermal failure principle, develop an intelligent algorithm and build a model to predict the plunger pump oil inlet and return port temperature and load pressure-volumetric efficiency.

[0026] This embodiment uses a neural network algorithm to predict the volumetric efficiency, which is only a special case of volumetric efficiency prediction. The neural network automatically extracts features by learning training data and generates outputs with specific functions. Its structure includes an input layer, a hidden layer, and an output layer. The collected and processed data is used as the input layer, that is, the input signal is the oil inlet temperature T i , oil return temperature Tr , load pressure P o The hidden layer converts the input into a more representative feature representation through a series of complex calculations. In this embodiment, the LBF layer is selected as the first hidden layer, which contains 128 neurons. Then two hidden layers are set, with 64 units in each layer. Finally, the output layer converts the results of the hidden layer into the result output, that is, the output volume efficiency η v The specific prediction process is as follows Figure 4 As shown;

[0027] Step 5: Based on the plunger pump oil inlet, oil return port temperature and load pressure-volume efficiency η v Prediction model, processes real-time temperature and pressure data, and calculates the real-time volumetric efficiency η of the plunger pump v , get the real-time volumetric efficiency prediction curve of the plunger pump, such as Figure 5 As shown, the model parameters are then adjusted according to the prediction error until the prediction requirements are met.

Claims

1. A method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and oil return port temperatures and load pressure, characterized in that: include: Temperature and pressure sensor data acquisition and processing; Calculates volumetric efficiency based on oil inlet and return port temperatures and load pressure. The specific steps are as follows: Step 1: The plunger pump is driven by a motor and connected via a coupling with a speed and torque sensor. Temperature sensors are installed at the oil inlet and oil return ports of the plunger pump, and a pressure sensor is installed at the outlet pipe of the plunger pump. Step 2: The signals collected by the temperature sensor and the pressure sensor are subjected to signal conditioning and digital-to-analog conversion devices; Step 3: Use a special algorithm to clean the converted data, remove the data that interferes with the calculation of the plunger pump volumetric efficiency, and obtain the oil inlet temperature T i , oil return temperature T r , load pressure P o ; Step 4: Based on the plunger pump's oil inlet and return port temperatures and load pressure data, and utilizing the plunger pump's thermal failure principle, develop an intelligent algorithm and build a model to predict the plunger pump's oil inlet and return port temperatures and load pressure-volume efficiency. Step 5: Based on the plunger pump oil inlet, oil return port temperature and load pressure-volume efficiency η v The prediction model is input with real-time temperature and pressure data to calculate the real-time volumetric efficiency η of the plunger pump. v .

2. The method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and oil return port temperatures and load pressure according to claim 1, characterized in that: In steps 1-5, it is emphasized that the sensors selected for detecting and calculating volumetric efficiency are temperature and pressure sensors. The temperature sensors are placed at the plunger pump's oil inlet and return port, and the pressure sensor is placed at the plunger pump's oil outlet. Their purpose is to measure the real-time temperature of typical parts of the plunger pump and the real-time outlet pressure of the entire pump, which serve as the data basis for calculating the real-time volumetric efficiency. The addition or reduction of the number of sensors or their combination with other sensors cannot change the patent's initial proposal of a method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and return port temperatures and load pressure.

3. The method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and oil return port temperatures and load pressure according to claim 1, characterized in that: In step 3, the data cleaning algorithm for the plunger pump's temperature and pressure sensors, as used in this method, specifically emphasizes the difference between this method's data removal process, which interferes with the calculation of the plunger pump's volumetric efficiency, and other online monitoring methods. This emphasizes the unique and irreplaceable role of this process in this method, as the removal of sample data with poor temperature characteristics (not specifically data outliers) significantly impacts the final volumetric efficiency calculation and prediction.

4. The method for predicting the volumetric efficiency of a plunger pump based on the oil inlet and oil return port temperatures and load pressure according to claim 1, characterized in that: In steps 4 and 5, the volumetric efficiency is calculated based on the oil inlet and return port temperatures and load pressure of the plunger pump. The plunger pump thermal failure principle, machine learning, regression analysis and other methods are used to establish the plunger pump oil inlet and return port temperature + load pressure - volumetric efficiency η v 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 the oil inlet, oil return port temperature and load pressure data to calculate the predicted volumetric efficiency.

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