All-metal conical screw pump flow efficiency test method

Abstract

The invention provides an all-metal conical screw pump flow efficiency test method. The test method comprises the following steps: correctly connecting an all-metal conical screw pump with a test platform; carrying out equipment preheating operation; adjusting the position of the rotor to the minimum value, and recording the position at the moment; starting a gap adjusting program, and setting an initial rotor position; starting a motor, regulating and setting the rotating speed of a rotor, regulating a pressure regulating valve, and recording pressure, flow and torque data; gradually reducing the gap between the stator and the rotor according to a preset gap adjustment scheme, and repeating the pressure and flow adjustment and data recording process after each adjustment; calculating flow efficiency; the performance of the all-metal conical screw pump under different working conditions is comprehensively evaluated, comprehensive data support is provided for performance evaluation of the pump, the relation between the flow efficiency and all parameters can be accurately obtained, optimization of design and operation of the pump is facilitated, the overall performance of the pump is improved, the service life of the pump is prolonged, and energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of screw pumps, and specifically to a flow efficiency test method for all-metal conical screw pumps. Background Art

[0002] A screw pump is a type of pump device that transports liquids through the rotation of a screw. It has the characteristics of simple structure, reliable operation, stable liquid transportation, and strong self-priming ability. Screw pumps can transport liquids with high viscosity, containing solid particles or gases, and thus are widely used in multiple industries. During the oil and gas transportation process, screw pumps can be used to transport substances such as crude oil, natural gas, and asphalt. Special types of screw pumps such as twin-screw multiphase pumps are also used for oil and gas multiphase transportation, that is, to transport crude oil containing sand, gas, and water from the oil well liquid storage tank to the gathering station over a long distance.

[0003] All-metal screw pumps have important applications in fields such as oil and gas exploitation. However, existing test methods mainly focus on the research of single performance indicators such as torque and volumetric efficiency, lacking a systematic test method for the comprehensive performance indicator of flow efficiency. Flow efficiency is crucial for evaluating the overall performance of all-metal conical screw pumps under different working conditions. It can take into account the wear and transportation capacity of the pump, providing a key basis for the optimized design and practical application of the pump. Currently, there is no comprehensive and effective test method specifically for the flow efficiency of all-metal conical screw pumps, which to a certain extent limits the performance improvement and wide application of this type of screw pump. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a flow efficiency test method for all-metal conical screw pumps to solve the problems raised in the above background art. The present invention provides comprehensive data support for the performance evaluation of pumps, can accurately obtain the relationship between flow efficiency and various parameters, helps to optimize the design and operation of pumps, improve the overall performance and service life of pumps, and reduce energy consumption.

[0005] In order to achieve the above purpose, the present invention is realized through the following technical solutions: A flow efficiency test method for all-metal conical screw pumps, the test method includes the following steps:

[0006] S1. Conduct test operations, correctly connect the all-metal conical screw pump to the test platform, and check the integrity of each connection component;

[0007] S2. Conduct preheating operation of the equipment to ensure normal operation of the system, and the voltage and frequency meet the equipment requirements;

[0008] S3. Adjust the rotor position to the minimum value, record the position at this time, and the clearance at this time is in the just-fitting state;

[0009] S4. Start the clearance adjustment program, precisely lift the rotor using the lifting adjustment system, and set the initial rotor position;

[0010] S5. Start the motor, regulate the set rotor speed, adjust the pressure regulating valve, and record the pressure, flow rate, and torque data respectively at different valve openings;

[0011] S6. Gradually reduce the clearance between the stator and the rotor according to the predetermined clearance adjustment plan, and repeat the above pressure and flow rate adjustment and data recording processes after each adjustment;

[0012] S7. Calculate the flow efficiency based on the recorded pressure, flow rate, and torque data;

[0013] S8. Comprehensively evaluate the performance of the all-metal conical screw pump under different working conditions according to the calculated flow efficiency and the recorded data such as torque and volumetric efficiency.

[0014] Furthermore, it also includes selecting the all-metal conical screw pump before the experiment, calibrating the screw pump to be tested to ensure its complete structure and normal performance, and recording the basic parameters of the screw pump to be tested.

[0015] Furthermore, it also includes building the test device, selecting a variable-frequency motor as the rotor power source, controlling the screw pump speed by adjusting the motor output frequency through the frequency converter; installing a torque meter to record the torque data in real time, a pressure gauge to monitor the system pressure, and a flow meter to measure the fluid flow rate; setting a pressure regulating valve to maintain the system pressure constant.

[0016] Furthermore, it also includes determining the test working conditions, selecting a representative fluid viscosity, simulating well depth data at different depths by changing the pressure application value, formulating a detailed test plan, clarifying the test process and data recording requirements, and preparing a data recording form.

[0017] Furthermore, in step S4, calculate and record the corresponding mating clearance, which should allow the accumulated liquid in the oil pipe to be discharged and reduce the starting torque.

[0018] Furthermore, in step S6, the clearance adjustment plan is divided into two stages. Taking the rotor position Ln as the boundary, when the rotor position is greater than Ln or less than Ln, the adjustment intervals are respectively adjusted to different parameters.

[0019] Furthermore, the formula for calculating the flow efficiency is as follows:

[0020]

[0021] Among them, η flow is the flow efficiency, m 3 / KW·h; Q act is the actual displacement, m 3 / d; n is the rotational speed, r / min; T tor is the torque, N·m.

[0022] Furthermore, by analyzing the relationship between the mating clearance corresponding to the peak flow efficiency and the reasonable range of the mating clearances corresponding to torque and volumetric efficiency, verify whether the flow efficiency index can balance the pump wear and conveying capacity, and provide reasonable suggestions for adjusting the mating clearance for the engineering application of the all-metal conical screw pump.

[0023] Furthermore, the basic parameters of the screw pump to be tested include the stator diameter at the suction end, the stator diameter at the discharge end, the lead, the effective pump length, the eccentricity, the theoretical displacement, the rated outlet pressure, the maximum tolerable temperature, the maximum fluid-adaptable viscosity, and the pump body design life.

[0024] Furthermore, the verification scope for the screw pump to be tested includes checking whether there are obvious damages or defects such as cracks, deformations, and corrosion on the pump body, the surface conditions of the rotor and stator, and there should be no foreign matter attachment and obvious wear marks; and checking the connecting components such as flanges, bolts, and pipe joints to ensure that their threads are complete, the seals are good, and there are no signs of looseness, and ensure the tightness and connection reliability of the entire test system.

[0025] Advantages of the present invention:

[0026] 1. The flow efficiency test method for the all-metal conical screw pump comprehensively evaluates the performance of the all-metal conical screw pump under different working conditions according to the calculated flow efficiency and the recorded data such as torque and volumetric efficiency. Analyze the relationship between the mating clearance corresponding to the peak flow efficiency and the reasonable range of the mating clearances corresponding to torque and volumetric efficiency, verify whether the flow efficiency index can balance the pump wear and conveying capacity, and provide reasonable suggestions for adjusting the mating clearance for the engineering application of the all-metal conical screw pump.

[0027] 2. The flow efficiency test method for the all-metal conical screw pump can systematically study the flow efficiency of the all-metal conical screw pump under different working conditions and provide comprehensive data support for the performance evaluation of the pump; by accurately controlling and adjusting parameters such as the medium viscosity, pressure, and mating clearance, the relationship between the flow efficiency and each parameter can be accurately obtained, which helps to optimize the pump design and operation.

[0028] 3. The flow efficiency test method for the all-metal conical screw pump is based on the flow efficiency index, can establish a reasonable mating clearance adjustment mechanism for the all-metal conical screw pump, improve the overall performance and service life of the pump, reduce energy consumption, and has important application value in fields such as oil and gas extraction. Description of the Drawings

[0029] Figure 1 is a schematic diagram of the test device of the present invention;

[0030] Figure 2It is the characteristic curve of torque and fit clearance under different pressure-viscosities in the embodiments of the present invention;

[0031] Figure 3 It is the characteristic curve of volumetric efficiency and fit clearance under different pressure-viscosities in the embodiments of the present invention;

[0032] Figure 4 It is the characteristic curve of flow efficiency and fit clearance under different pressure-viscosities in the embodiments of the present invention. Specific embodiments

[0033] To make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0034] Please refer to Figures 1 to 4 , the present invention provides the following technical solutions: a flow efficiency test method for a full-metal conical screw pump, specifically including the following steps:

[0035] Step 1, use a GLB-258-24-S type full-metal conical screw pump for the test, ensure its complete structure and normal performance, and record its basic parameters, including the stator diameter at the suction end, the stator diameter at the discharge end, the lead, the effective pump length, the eccentricity, the theoretical displacement, the rated outlet pressure, the maximum bearing temperature, the maximum fluid adaptation viscosity, and the pump body design life, etc.

[0036] Conduct a comprehensive inspection of the appearance of the pump, check whether there are obvious damages or defects such as cracks, deformations, and corrosions on the pump body, especially the surface conditions of the rotor and stator, and there should be no foreign matter attachment and obvious wear marks. Check the connecting parts such as flanges, bolts, and pipe joints to ensure that their threads are complete, the seals are good, and there are no signs of looseness, and ensure the tightness and connection reliability of the entire test system

[0037] Build a test device, including selecting a variable-frequency motor as the rotor power source, adjusting the motor output frequency through a frequency converter to control the screw pump speed; installing a torque meter to record torque data in real time, a pressure gauge to monitor the system pressure, and a flow meter to measure the fluid flow; setting a pressure regulating valve to maintain the system pressure constant

[0038] According to the test plan, determine the working condition parameters to be tested, where the medium viscosity is 1 mPa·s and 50 mPa·s, the pressure application values are 5 MPa and 10 MPa, the screw pump speed is 100 r / min, etc., and record these parameters in detail in a pre-prepared data recording form. The data recording form should be reasonably designed, including columns such as test serial number, time, working condition parameters, measured torque, pressure, flow, etc. data, as well as calculation results such as flow efficiency and volumetric efficiency, etc., so as to clearly and accurately record and organize the test data.

[0039] Step 2, for the low-viscosity fluid simulating 1 mPa·s, deionized water meeting the laboratory standards is selected as the transport medium. Before use, the viscosity of the water is measured using a high-precision viscometer to ensure that its viscosity is within the range of 1 mPa·s ± 0.05 mPa·s.

[0040] For the medium-viscosity fluid simulating 50 mPa·s, an appropriate amount of special thickener is added to the deionized water. During the addition process, slow stirring is required to evenly disperse the thickener in the water, avoiding the formation of agglomerates or bubbles. After the addition is completed, the mixed solution is measured and calibrated multiple times using a viscometer to ensure that its viscosity is stably within the range of 50 mPa·s ± 1 mPa·s. At the same time, record information such as the addition amount and brand of the thickener for the repeatability and accuracy of subsequent tests.

[0041] Step 3, operate the lifting motor to adjust the position of the screw pump rotor to the minimum value. At this time, the full-metal conical screw pump has an exactly matching clearance. Use a displacement sensor with a precision of 0.1 mm to measure and record the initial position L0 of the rotor at this time as -5 mm. During the adjustment process, closely observe the movement state of the rotor to ensure its smooth movement without jamming or abnormal vibration.

[0042] According to the test plan, start the clearance adjustment program. Send precise control commands to the lifting motor through the control cabinet to lift the rotor to the predetermined initial position of 85 mm. The corresponding clearance at this position is 0.0443 mm. During the adjustment process, use a high-precision clearance measuring instrument to monitor the change of the clearance in real time to ensure that the set initial clearance value is reached, with the error controlled within ±0.0005 mm. This clearance setting can effectively discharge the liquid accumulated in the oil pipe, reduce the starting torque, and create favorable conditions for the smooth progress of subsequent tests.

[0043] Step 4, after confirming that the rotor position and clearance adjustment are in place and the system is ready, start the main motor. Precisely set the motor speed to 100 r / min through the frequency converter, and at the same time observe the starting process of the motor to ensure that the motor starts smoothly without abnormal noise and vibration. Within the first 5 minutes after the motor starts, closely monitor the reading changes of the torque meter, pressure gauge, and flow meter to ensure that all instruments and meters are working properly and the data is stable.

[0044] After the motor runs stably and the data acquisition is normal, operate the pressure regulating valve and gradually change the valve opening degree in ascending order. At each opening degree, wait for the system pressure to stabilize for 2 - 3 minutes, and then record the pressure values displayed by pressure gauge 1 and pressure gauge 2, the flow value recorded by the flow meter, and the torque data measured by the torque meter at this time. During the adjustment process, closely observe the pressure change trend of the system to ensure the smoothness and accuracy of pressure adjustment and avoid the impact of pressure mutations on the test results.

[0045] Step 5, after completing the data recording at a set opening of the pressure regulating valve, reduce the clearance between the stator and the rotor according to a predetermined clearance adjustment scheme. During the clearance adjustment process, slowly move the rotor using the lifting motor. After each adjustment, use the clearance measuring instrument to confirm again whether the mating clearance reaches the expected value. After the clearance adjustment is completed, repeat the above pressure and flow rate adjustment process and record the corresponding data. Taking the rotor position Ln as the boundary, when the rotor position is greater than Ln or less than Ln, adjust the intervals to different parameters respectively. The adjustment relationship between the rotor position and the adjustment interval in this embodiment is shown in the following table:

[0046] Table 1: Adjustment relationship between rotor position and adjustment interval

[0047] Rotor position Ln Adjustment interval Corresponding clearance change interval > 35 mm 10 mm 0.0052 mm ≤ 35 mm 2 mm 0.00104 mm

[0048] Taking the rotor position Ln = 35 mm as the boundary, when the rotor position is greater than Ln, the adjustment interval is 10 mm (corresponding to a clearance change interval of 0.0052 mm); when the rotor position is less than Ln, the adjustment interval is 2 mm (corresponding to a clearance change interval of 0.00104 mm). During the entire clearance adjustment and data recording process, keep the test environment and other operating condition parameters stable to ensure the comparability and reliability of the data.

[0049] Step 6, according to the recorded torque T tor (N·m), actual displacement Q act (m 3 / d), and rotational speed n (r / min), calculate the flow efficiency η flow (m 3 / KW·h) according to the following formula:

[0050]

[0051] Use data processing software to plot the flow efficiency - mating clearance characteristic curves under different pressure - viscosities. When plotting the curves, select appropriate axis scales and curve fitting methods so that the curves can clearly show the trend of the flow efficiency changing with the mating clearance. Through the analysis of the curves, observe the change rules of the flow efficiency under different operating conditions, and determine the mating clearance value corresponding to the peak value of the flow efficiency curve. At the same time, combined with the changes in torque and actual flow rate, analyze the internal relationship between the flow efficiency and these parameters, evaluate the conveying efficiency and energy consumption of the system under this clearance state, and provide data support and theoretical basis for the performance optimization of the all - metal conical screw pump

[0052] Step 7: Comprehensively analyze the calculated flow efficiency together with the recorded data such as torque and volumetric efficiency. Compare the changes in these performance indicators under different working conditions, and evaluate the overall performance of the all-metal conical screw pump under conditions such as different medium viscosities, pressure values, and mating clearances. Analyze the changing trends of the pump's flow efficiency, torque, and volumetric efficiency under high-viscosity medium and high-pressure working conditions, and judge the adaptability and reliability of the pump.

[0053] In this embodiment, the relationship between the mating clearance corresponding to the peak value of the flow efficiency and the reasonable range of the mating clearances corresponding to the torque and volumetric efficiency is deeply analyzed. According to the test results, determine the optimal mating clearance range of the all-metal conical screw pump under different working conditions on the premise of taking into account the pump's wear and conveying capacity. For example, if the mating clearance corresponding to the peak value of the flow efficiency is within the intersection of the double-optimal intervals of the torque and volumetric efficiency, and the overall performance of the pump is the best at this clearance, then this clearance range is used as the recommended mating clearance adjustment range. Combining the actual engineering application requirements, propose reasonable mating clearance adjustment strategies and suggestions, provide scientific guidance for the engineering application of the all-metal conical screw pump, improve the pump's operating efficiency and service life, and reduce energy consumption and maintenance costs.

[0054] Comprehensively evaluate the performance of the all-metal conical screw pump under different working conditions based on the flow efficiency calculated by the above method and the recorded data such as torque and volumetric efficiency. Analyze the relationship between the mating clearance corresponding to the peak value of the flow efficiency and the reasonable range of the mating clearances corresponding to the torque and volumetric efficiency, and verify whether the flow efficiency index can take into account the pump's wear and conveying capacity, so as to provide reasonable mating clearance adjustment suggestions for the engineering application of the all-metal conical screw pump.

[0055] The above has shown and described the basic principles, main features, and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic features of the present invention, the present invention can be implemented in other specific forms.

[0056] In addition, it should be understood that although this specification is described according to embodiments, not each embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. All-metal conical screw pump flow efficiency test method, characterized by: The experimental method includes the following steps: S1. Perform the test operation, correctly connect the all-metal conical screw pump to the test platform, and check the integrity of each connecting component; S2. Preheat the equipment to ensure that the system works normally and the voltage and frequency meet the equipment requirements; S3, adjust the rotor position to the minimum value, record the position at this time, and the matching clearance is just matched at this time; S4, start the gap adjustment program, use the lifting and lowering adjustment system to accurately lift the rotor and set the initial rotor position; S5, start the motor, set the rotor speed, adjust the pressure regulating valve, and record the pressure, flow and torque data at different valve openings; S6. gradually reducing the gap between the stator and the rotor according to a predetermined gap adjustment scheme, and repeating the above pressure and flow adjustment and data recording process after each adjustment; S7, calculating flow efficiency based on the recorded pressure, flow and torque data; S8. Comprehensively evaluate the performance of the all-metal conical screw pump under different working conditions based on the calculated flow efficiency and recorded torque, volumetric efficiency and other data.

2. The flow efficiency test method of the all-metal conical screw pump according to claim 1 is characterized in that: It also includes selecting the all-metal conical screw pump before the experiment, calibrating the screw pump to be tested to ensure its structural integrity and normal performance, and recording the basic parameters of the screw pump to be tested.

3. The flow efficiency test method of the all-metal conical screw pump according to claim 1 is characterized in that: It also includes building a test device, selecting a variable frequency motor as the rotor power source, and controlling the speed of the screw pump by adjusting the motor output frequency through the frequency converter; installing a torque meter to record torque data in real time, a pressure gauge to monitor system pressure, and a flow meter to measure fluid flow; and setting a pressure regulating valve to maintain a constant system pressure.

4. The flow efficiency test method of the all-metal conical screw pump according to claim 1, characterized in that: It also includes determining the test conditions, selecting representative fluid viscosities, simulating well depth data at different depths by changing the pressure values, developing a detailed test plan, clarifying the test process and data recording requirements, and preparing data recording tables.

5. The flow efficiency test method of the all-metal conical screw pump according to claim 1, characterized in that: In step S4, the corresponding fitting clearance is calculated and recorded. The clearance should allow the liquid accumulated in the oil pipe to be unloaded to reduce the starting torque.

6. The flow efficiency test method of the all-metal conical screw pump according to claim 1, characterized in that: In step S6, the gap adjustment scheme is divided into two stages, with the rotor position Ln as the boundary, and the gap is adjusted to different parameters when the rotor position is greater than Ln or less than Ln.

7. The flow efficiency test method of the all-metal conical screw pump according to claim 6 is characterized in that: The formula for calculating flow efficiency is as follows: Among them, η flow is the flow efficiency, m 3 / KW·h;Q act is the actual displacement, m 3 / d; n is the speed, r / min; T tor is the torque, N·m.

8. The flow efficiency test method of the all-metal conical screw pump according to claim 1, characterized in that: By analyzing the relationship between the fit clearance corresponding to the flow efficiency peak and the reasonable range of the fit clearance corresponding to the torque and volumetric efficiency, it is verified whether the flow efficiency index can take into account the wear and delivery capacity of the pump, and reasonable fit clearance adjustment suggestions are provided for the engineering application of all-metal conical screw pumps.

9. The flow efficiency test method of an all-metal conical screw pump according to claim 2, characterized in that: The basic parameters of the screw pump to be tested include the stator diameter at the suction end, the stator diameter at the discharge end, the lead, the effective pump length, the eccentricity, the theoretical displacement, the rated outlet pressure, the maximum withstand temperature, the maximum fluid adaptability viscosity and the design life of the pump body.

10. The flow efficiency test method of an all-metal conical screw pump according to claim 2, characterized in that: The scope of verification for the screw pump to be tested includes checking whether the pump body has obvious damage or defects such as cracks, deformation, corrosion, etc., and the surface condition of the rotor and stator, which should be free of foreign matter and obvious signs of wear; and checking the flanges, bolts, pipe joints and other connecting parts to ensure that their threads are intact, well sealed and without signs of looseness, to ensure the sealing and connection reliability of the entire test system.

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