Hydraulic pipe-piping turbulent flushing process based on multi-parameter dynamic regulation

Abstract

The application discloses a hydraulic pipe turbulent flushing process based on multi-parameter dynamic regulation, directly reuses hydraulic system body components to build a flushing pipeline, does not need to additionally increase equipment or pipelines, greatly reduces equipment investment cost, is simple and convenient to operate and is extremely strong in universality; Re is greater than or equal to 4000 as a turbulent criterion, through independent high-frequency sensing of a branch and millisecond-level closed-loop automatic regulation, it is ensured that each branch is in a stable and complete turbulent state throughout the process, and technical pain points that traditional process parameters depend on manual experience are completely solved; a Reynolds number and a multi-parameter quantitative coupling model are innovatively constructed, accurate collaborative regulation of flow, pressure and temperature is realized, only two kinds of simplified flushing modes are set to adapt to the demand of branches of all specifications, and overall operation efficiency is increased by more than 80%; the whole process effectively meets the flushing quality requirement of high-cleanliness hydraulic pipelines, and effectively speeds up the engineering construction progress.

Description

Technical Field

[0001] This invention relates to the field of hydraulic system maintenance technology, specifically to a hydraulic piping turbulent flushing process based on multi-parameter dynamic control. The flushing pipeline is constructed based on the hydraulic system's main components and actual oil circuit logic, offering two modes: single-branch flushing and combined full-branch flushing. By constructing a Reynolds number-multi-parameter quantitative coupling model to determine the turbulence control threshold, and combining independent pressure, flow, and temperature sensing monitoring of each branch with millisecond-level closed-loop adjustment, the entire pipeline is kept in a fully turbulent state with Re ≥ 4000. This method is particularly suitable for flushing operations of hydraulic systems in engineering machinery, metallurgical equipment, and machine tools that utilize the main hydraulic components to construct the flushing pipeline. Background Technology

[0002] During the processing and installation of hydraulic piping, impurities such as iron filings, welding slag, and dust may remain. If not effectively flushed, these impurities will enter the hydraulic actuators and valve assemblies, causing component wear and jamming, and affecting the operational accuracy and service life of the hydraulic system. Existing hydraulic piping flushing processes mostly use constant flow flushing with fixed parameters, failing to precisely control the turbulence state based on the Reynolds number. Furthermore, the flushing pipeline combinations are limited and cannot adapt to the characteristics of different pipe diameters and branches. Additionally, the coordinated thresholds for flow rate, pressure, and temperature under turbulent conditions are not clearly defined, resulting in unstable turbulence during flushing, poor impurity removal, and low flushing efficiency.

[0003] Existing similar patents, such as Chinese invention patent with publication number CN101386012B, disclose a gas-liquid mixing flushing method for hydraulic and lubrication pipelines. First, compressed air is used to blow away dirt inside the pipeline, and then an oil flushing device is used to flush the pipeline. The flushing oil is sampled and tested at intervals until the test results meet the requirements. This technology does not involve constructing a Reynolds number and multi-parameter quantitative coupling model, and cannot achieve precise coordinated control of flow, pressure, and temperature. It also does not set two simplified flushing modes to adapt to the needs of all branch specifications.

[0004] Based on a comprehensive analysis of existing technologies, their common shortcomings are mainly reflected in the following three core technical challenges: the reuse of hydraulic system components, the matching of Reynolds number and multi-parameter collaborative thresholds, and the intelligent control of graded Reynolds number. At the same time, there are also problems such as insufficient flushing adaptability and low parameter control accuracy.

[0005] In summary, current technology is insufficient to meet the precise flushing requirements of complex hydraulic piping in high-end equipment, and there is an urgent need to develop a hydraulic piping turbulence flushing process based on multi-parameter dynamic control. Summary of the Invention

[0006] The purpose of this invention is to provide a hydraulic piping turbulent flushing process based on multi-parameter dynamic control. This process utilizes hydraulic system components to construct flushing pipelines, follows actual oil circuit logic to achieve constant temperature heating and stable oil supply, establishes a quantitative coupling model of Reynolds number and multiple parameters, enables independent high-frequency monitoring and millisecond-level closed-loop adjustment of individual branches, and adapts to both single-branch and combined-branch flushing modes. This ensures that each pipeline is in a fully turbulent state with Re ≥ 4000 throughout the flushing process, improving flushing efficiency and piping cleanliness while reducing equipment investment costs.

[0007] Core design principles: The flushing pipeline is built entirely based on the hydraulic system components, following the actual oil circuit logic. The oil temperature is monitored using the tank's built-in temperature gauge, eliminating the need for additional sensors, pipelines, or other components, thus reducing equipment costs. With Re≥4000 as the core constraint, all operations revolve around maintaining a fully turbulent state. Parameter fine-tuning is performed during filtration, filter replacement, and branch switching to ensure uninterrupted turbulence. Each hydraulic branch acts as an independent control unit, enabling independent monitoring and adjustment of flow rate, pressure, and temperature. When flushing all branches simultaneously, power dispersion is avoided, adapting to the needs of different branch specifications. Clearly defined turbulence control thresholds for temperature, pressure, and flow rate are established, creating a quantitative coupling relationship between these three parameters and the Reynolds number, achieving multi-parameter coordinated control and improving turbulence stability. Two flushing modes are provided: single-branch and full-branch combined flushing, catering to practical application needs, simplifying the operation process, and improving flushing efficiency.

[0008] Core turbulence control threshold: oil temperature threshold 40~50℃, within this range 46 # / 68 # The anti-wear hydraulic oil exhibits a stable low kinematic viscosity, which is beneficial for increasing the flow velocity in the pipe and maintaining turbulence. Temperature fluctuations are monitored by a tank temperature gauge and are ≤±2℃. Pressure thresholds are ≤2.5MPa for branches of DN50 and above, and ≤1.5MPa for branches of DN40 and below, with pressure fluctuations ≤±0.1MPa, ensuring stable flow and preventing pipe leakage or flow instability. Flow thresholds are ≤±2L / min for DN15 (15~20L / min), DN20 (20~30L / min), DN25 (25~35L / min), DN40 (45~55L / min), DN50 (75~85L / min), DN65 (95~105L / min), DN80 (120~130L / min), and DN100 (140~150L / min), ensuring stable flow velocity in the pipe and guaranteeing Re≥4000.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A hydraulic piping turbulent flushing process based on multi-parameter dynamic control is proposed. This process utilizes the hydraulic system's main components to construct a closed-loop flushing pipeline, adapting to both single-branch and combined-branch flushing modes. It achieves turbulence optimization and multi-parameter dynamic control, specifically including the following steps:

[0011] S1: Constructing a Reynolds number-multi-parameter quantization coupling model and a pipeline turbulence threshold library

[0012] A Reynolds number-multi-parameter quantitative coupling model with Re≥4000 as the core is established, integrating the quantitative relationships between Reynolds number, pipe velocity, flow rate, pressure, temperature, and medium viscosity. The core formula is:

[0013] 1) Reynolds number formula: Re = v·d / ν (v is the average flow velocity in the pipe, m / s; d is the inner diameter of the pipe, m; ν is the kinematic viscosity of the medium, m² / s).

[0014] 2) Flow rate to velocity conversion formula: Q = v×πd² / 4×60×1000 (Q is the flushing flow rate, L / min);

[0015] 3) Friction pressure loss formula: ΔP =λ·(L / d)·(ρv² / 2) (λ=0.3164 / Re^0.25; L is the pipe length, m; ρ is the medium density, kg / m³).

[0016] 4) Flushing power matching formula: P = Q·ΔP / (60η) (η is the pump efficiency, with a value of 0.75~0.85; P is the flushing power, kW).

[0017] Hydraulic pipeline parameters of full diameter (DN15~DN100), different lengths, wall thicknesses, and materials were collected, along with the kinematic viscosity and density parameters of anti-wear hydraulic oil at 30~60℃. Through quantitative coupling model calculations, the minimum critical flow rate and pressure required for different pipelines to maintain Re≥4000 were determined. Combined with the core thresholds of oil temperature, pressure, and flow rate, a standardized, comprehensive pipeline turbulence critical threshold library was compiled to provide data support for parameter solving.

[0018] S2: Intelligent solution for optimal matching parameters of turbulence in each branch and the combined turbulence of all branches.

[0019] Based on the actual parameters (pipe diameter, length, wall thickness, material) of the hydraulic branch to be flushed, the minimum critical flow rate, pressure, and other basic data of this branch at 40~50℃ are retrieved from the turbulence critical threshold library, and 46 are selected. # Or 68 # Anti-wear hydraulic oil is used as the flushing medium, and all data are input into the Reynolds number-multi-parameter quantization coupling model.

[0020] With Re ≥ 4000 as a hard constraint, and maximizing turbulence intensity and minimizing pressure loss as the dual objective functions, a particle swarm optimization (PSO) algorithm or a genetic algorithm is selected for intelligent parameter optimization. The PSO algorithm uses a learning factor of 1.5–2.0 and an inertia weight of 0.6–0.9, while the genetic algorithm uses a crossover probability of 0.6–0.8 and a mutation probability of 0.01–0.05. After the algorithm iteration is complete, it automatically outputs the exclusive optimal flow and pressure parameters for single flushing of each branch and combined flushing of all branches. These parameters have a ±10% resistance to fluctuations, ensuring that the Reynolds number remains ≥ 4000 even with small changes in operating conditions.

[0021] S3: Build a closed-loop flushing pipeline based on the main components.

[0022] Based on the hydraulic system components, and following the oil circuit logic sequence of "constant temperature heating of the oil tank, stable oil supply, branch distribution, return oil filtration and sewage discharge, and return to the oil tank," a closed-loop flushing pipeline is constructed, with the specific configuration as follows:

[0023] Oil heating and primary oil supply: The electronic heater directly heats the flushing medium in the oil tank at a constant temperature, and the oil temperature is monitored in real time by a temperature gauge and maintained at 40~50℃; the oil from the oil tank passes through the inlet filter and the variable main oil pump in sequence to the main oil inlet pipeline, realizing the primary filtration of the medium and power transmission.

[0024] Staged pressure regulation and flow merging: The medium in the main oil inlet pipeline is divided into two paths after passing through the ball valve and the overflow valve. One path goes through the oil booster pipeline, the adjustable oil booster pump, and the check valve, while the other path goes directly through the check valve. The two paths merge to achieve flow replenishment and pressure stabilization. After merging, the medium passes through the flow meter and pressure gauge to complete the main path parameter monitoring, and then is connected to the main oil inlet pipeline.

[0025] Branch line distribution: The main oil inlet line is connected to each hydraulic branch line via an electromagnetic directional valve. The actuator is connected to a short-circuit line to ensure that the medium participates in the flushing of the branch line in full. Each hydraulic branch line is independently equipped with pressure, flow and temperature sensors to achieve accurate monitoring of branch line parameters.

[0026] Return oil filtration and closed loop: The medium from all hydraulic branches is collected in the main return oil pipe, and then passes through the return oil filter to filter impurities, drain valve, drain pipe and drain port to discharge deposited impurities. Finally, the clean medium flows back to the oil tank, forming a closed loop flushing circuit.

[0027] Fuel tank auxiliary configuration: The top of the fuel tank is equipped with a vent cap and a level gauge, and the side wall is equipped with a temperature gauge, which respectively realizes fuel tank venting, fuel level monitoring and intuitive display of fuel temperature.

[0028] S4: Implementation of turbulence control for single-branch and combined-branch flows

[0029] Following the principle of "first single branch, then merging all branches," turbulence control in two modes is achieved through the linkage adjustment of the electromagnetic reversing valve with the variable main oil pump and the adjustable booster pump. Specific steps are as follows:

[0030] Single-branch turbulent flushing: Close the solenoid directional valves of all other branches, open only the solenoid directional valve of the target branch, adjust the frequency of the variable main oil pump to the optimal flow rate of the branch, and adjust the pressure to the optimal pressure with the relief valve. Monitor the branch with the branch sensor and Reynolds number monitor to ensure that the Re of the branch is ≥4000. Complete the single-branch turbulent flushing of all branches in this way.

[0031] Full-branch combined turbulent flushing: Simultaneously open the solenoid directional valves of all branches, adjust the variable main oil pump to the base flow rate, and start the adjustable booster pump to supplement the flow and pressure according to the total flow requirements of each branch, ensuring that the total flow of the main line meets the combined flushing requirements; by independently adjusting the opening of the solenoid directional valves of each branch, the flow and pressure of each branch are precisely matched to their optimal parameters, ensuring that the Re of all branches is ≥4000, and achieving coordinated maintenance of turbulent flow in the combined flushing of all branches.

[0032] S5: Independent branch monitoring and millisecond-level dynamic closed-loop adjustment

[0033] Reynolds number monitors are installed in each hydraulic branch, and together with the pressure, flow and temperature sensors built into the branch, an independent monitoring system is built for each branch. All monitoring devices collect data at a sampling frequency of ≤1 second and transmit it to the PLC control system in real time via industrial Ethernet. The control system touch screen displays the real-time parameter values, threshold ranges and Reynolds number change curves of each branch.

[0034] The PLC control system has built-in turbulence state maintenance logic. When the monitored data deviates from the preset threshold or the Reynolds number is less than 4000, the control system automatically and accurately corrects the parameters within 5 seconds. The core adjustment logic is as follows:

[0035] Low Reynolds number and insufficient flow: Directly increase the frequency of the variable main oil pump (single branch / main line) or the adjustable booster pump (combined flushing) to increase the flow rate of the corresponding branch and increase the flow velocity in the pipe to a Reynolds number ≥ 4000.

[0036] Low Reynolds number and insufficient pressure: First, adjust the relief valve to increase the system oil supply pressure and solve the problem of flow instability caused by pressure loss. Then, fine-tune the frequency of the oil pump to bring the flow back to the threshold range and maintain a Reynolds number ≥ 4000.

[0037] If the Reynolds number is low and the oil temperature is <40℃: Immediately start the electronic heater to heat the oil in the tank at a constant temperature. Monitor the temperature in real time with a temperature gauge until the oil temperature rises back to 40~50℃, reduce the kinematic viscosity of the medium, and achieve a rapid increase in the Reynolds number. Maintain the pressure and flow rate within the threshold throughout the process.

[0038] Deviation of parameters in a single branch during combined flushing: Without changing the parameters of the main oil supply system, the opening of the solenoid directional valve of the branch is adjusted independently to achieve precise correction of the flow and pressure of the single branch, ensuring that the Reynolds number of the branch is ≥4000.

[0039] Filter blockage leads to increased pressure: The system automatically prompts for filter replacement, while fine-tuning the overflow valve and oil pump frequency converter to compensate for pressure and flow changes, ensuring stable parameters in each branch and a Reynolds number ≥ 4000.

[0040] S6: Graded gradient filtration and circulating flushing under turbulent conditions

[0041] Under the premise that the PLC control system maintains complete turbulence in each branch, graded gradient filtration is achieved through a switchable dual-element return oil filter in the order of "first single branch, then merging all branches". The specific process is as follows:

[0042] Initial flushing stage: Switch the return oil filter to a 10μm precision filter element with a dirt holding capacity of ≥100g, and perform initial flushing on each branch in sequence, with each branch flushed continuously for 48 hours; after the initial flushing of each branch is completed, switch to the combined mode of all branches and continue initial flushing for 48 hours while maintaining turbulence. Under the fully turbulent state, welding slag, oxide scale, and large iron filings on the inner wall of the pipeline are continuously stripped off by the turbulent shear force and promptly filtered and removed by the 10μm filter element, avoiding secondary pollution caused by the circulation of large particulate impurities.

[0043] Fine rinsing stage: After the initial rinsing is completed, the return oil filter is switched to a 3μm high-precision filter element without stopping the machine. The filter element has a filtration ratio β≥200. Fine rinsing is performed in the same order of single branch and full branch merging. The fine rinsing time is 24~48 hours (adjusted according to the degree of pipeline contamination). Turbulent shear force continuously peels off the tiny particulate impurities on the inner wall of the pipeline, which are efficiently removed by the 3μm filter element, greatly improving the cleanliness of the oil and pipeline.

[0044] Circulating flushing and filter element replacement: The filtered clean flushing medium is re-entered into the flushing circuit through a variable main oil pump, realizing the recycling of the medium and reducing the medium waste rate to below 5%; both 10μm and 3μm filter elements are equipped with differential pressure monitoring devices. When the differential pressure is ≥0.15MPa, the system automatically prompts to replace the filter element. During the replacement process, the parameters are finely adjusted by the PLC control system to ensure that the Reynolds number of each branch is ≥4000 and the turbulent state is uninterrupted.

[0045] S7: Acceptance of Turbulent Flushing Effect

[0046] After all branch lines are thoroughly flushed, the cleanliness of the oil is tested using an online laser particle counter installed on the main return oil line. The testing standards strictly adhere to the NAS1638 classification standard.

[0047] If the test results meet the corresponding quality standard level in NAS1638, the hydraulic piping is deemed to have passed the turbulent flushing test. The PLC control system then sequentially shuts down the solenoid directional valves of each branch, the variable main oil pump, and the adjustable booster pump to complete the flushing operation. If the test results do not meet the corresponding quality standard level in NAS1638, the turbulent state is not shut off. The fully turbulent state of all branches is maintained and fine flushing is performed until the cleanliness test meets the standard.

[0048] After all pipelines have passed the flushing test, the PLC control system automatically records the flushing data throughout the process, including pressure, flow rate, temperature, Reynolds number parameter change curves, filter replacement records, and cleanliness test data during the single flushing of each branch and the combined flushing of all branches. This forms a complete turbulent flushing quality acceptance report, which serves as the quality basis for the commissioning of the hydraulic system.

[0049] Compared with the prior art, the beneficial effects of the present invention are:

[0050] The present invention provides a hydraulic piping turbulent flushing process based on multi-parameter dynamic control, which has the following significant advantages compared with the prior art:

[0051] This invention directly reuses hydraulic system components to build flushing pipelines, eliminating the need for additional equipment or pipelines, significantly reducing equipment investment costs. It is easy to operate and highly versatile. Using Re≥4000 as the turbulence criterion, it ensures that each branch is in a stable, fully turbulent state throughout the process through independent high-frequency sensing and millisecond-level closed-loop automatic adjustment, completely solving the technical pain point of traditional process parameters relying on manual experience. It innovatively constructs a Reynolds number and multi-parameter quantitative coupling model to achieve precise and coordinated control of flow rate, pressure, and temperature. Two simplified flushing modes can adapt to the needs of all branch specifications, improving overall work efficiency by over 80%. The entire process effectively meets the flushing quality requirements of high-cleanliness hydraulic pipelines, significantly accelerating project construction progress. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of a hydraulic piping turbulent flushing process based on multi-parameter dynamic control.

[0053] In the picture:

[0054] 1. Oil tank; 2. Shut-off valve; 3. Level gauge; 4. Inlet filter; 5. Electronic heater; 6. Thermometer; 7. Vent cap; 8. Main inlet oil line; 9. Ball valve; 10. Variable main oil pump; 11. Overflow valve; 12. Incremental oil line; 13. Adjustable incremental oil pump; 14. Flow meter; 15. Check valve; 16. Pressure gauge; 17. Temperature sensor; 18. Main inlet oil line; 19. Solenoid directional valve; 20. Exhaust valve; 21. Actuator; 22. Short pipe line; 23. Hydraulic branch line; 24. Main return oil line; 25. Detection port; 26. Drain valve; 27. Drain pipe; 28. Drain outlet; 29. ​​Return oil filter; 30. Pressure sensor; 31. Flow sensor. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0056] Example 1:

[0057] Please see Figure 1 In this embodiment of the invention, a hydraulic piping turbulent flushing process based on multi-parameter dynamic control is provided. The embodiment relies on a closed-loop flushing pipeline constructed from the hydraulic system's main components. For a hydraulic piping combination consisting of one DN65 carbon steel branch (360 meters long, 5mm wall thickness) and two DN32 stainless steel branches (585 meters long, 3mm wall thickness each), the hydraulic pipeline flushing quality level requirement is NAS1638 Grade 6, using 46... # Anti-wear hydraulic oil is used as the flushing medium. The specific operating steps of the present invention are explained in detail to verify the turbulence control effect of single branch and full branch merging and the ability to dynamically adjust multiple parameters.

[0058] In the above embodiment, the flushing system includes: an oil tank 1, a shut-off valve 2, a level gauge 3, an inlet oil filter 4, an electronic heater 5, a thermometer 6, a vent cap 7, a main oil inlet pipeline 8, a ball valve 9, a variable main oil pump 10, an overflow valve 11, an oil booster pipeline 12, an adjustable oil booster pump 13, a flow meter 14, a check valve 15, a pressure gauge 16, a temperature sensor 17, a main oil inlet pipeline 18, a solenoid directional valve 19, an exhaust valve 20, an actuator 21, a short pipeline 22, a hydraulic branch pipeline 23, a main return oil pipeline 24, a detection port 25, a drain valve 26, a drain pipe 27, a drain outlet 28, a return oil filter 29, a pressure sensor 30, and a flow sensor 31.

[0059] In the above embodiments, the implementation steps are as follows:

[0060] Step 1: Model Construction and Parameter Retrieval. A Reynolds number-multi-parameter quantization coupled model is established, and DN65, DN32, and DN46 branches are retrieved from the turbulence critical threshold library. # Parameters of anti-wear hydraulic oil at 45℃, of which 46 # The hydraulic oil has a kinematic viscosity of 35 mm² / s and a density of 890 kg / m³. The minimum critical flow rate for the DN65 branch to maintain Re≥4000 is 95 L / min and the pressure is 1.8 MPa. The minimum critical flow rate for the DN32 branch is 40 L / min and the pressure is 1.0 MPa.

[0061] Step 2: Intelligent solution for optimal parameters. The pipeline and medium parameters are input into the coupled model, and the particle swarm optimization algorithm (learning factor 1.8, inertia weight 0.7) is used to find the optimal parameters: DN65 branch single flushing flow rate 100L / min, pressure 2.0MPa (Re=4920≥4000); single DN32 branch single flushing flow rate 45L / min, pressure 1.2MPa (Re=4850≥4000); total combined flushing flow rate of all branches is 190L / min (DN65 branch 100L / min and 2 DN32 branches each 45L / min), provided by variable main oil pump 10 100L / min, and adjustable booster pump 13 supplementing pressure by 90L / min.

[0062] The third step is to construct a closed-loop pipeline. Construct a closed-loop flushing pipeline according to the connection routes of the main components. This includes 5 pairs of electronic heaters and 1 oil tank (46). # Hydraulic oil is heated, and the temperature is monitored and maintained at 45℃ by temperature gauge 6. Oil from tank 1 is connected to the main oil inlet line 8 via oil inlet filter 4 and variable main oil pump 10. After passing through ball valve 9 and overflow valve 11, the oil is divided and repressurized, and then connected to the main oil inlet line 18 via flow meter 14 and pressure gauge 16. It is then divided into 3 branches via solenoid directional valve 19. Each branch is equipped with pressure sensor 30, flow sensor 31, temperature sensor 17 and Reynolds number monitor. All branches are connected to the main return oil line 24, and the oil flows back to tank 1 via return oil filter 29 and drain valve 26, completing the closed loop construction.

[0063] The fourth step is to control turbulence by combining single-branch and full-branch flows.

[0064] 1) Close the solenoid directional valves 19 of the other two branches, open the valve of the DN65 branch, adjust the variable main oil pump to 10 to 100 L / min and the overflow valve to 2.0 MPa, monitor and display Re=4920, and complete the single flushing of the DN65 branch.

[0065] 2) Sequentially start the single flushing of two DN32 branch lines, adjust the variable main oil pump to 10 to 45 L / min and the overflow valve to 11 to 1.2 MPa, and monitor the display Re = 4850;

[0066] 3) Simultaneously open the valves of 3 branches, adjust the variable main oil pump 10 to 100L / min, start the adjustable booster pump 13 to 90L / min, adjust the opening of the solenoid reversing valve 19 of each branch, so that the DN65 branch maintains 100L / min and 2.0MPa, and each DN32 branch maintains 45L / min and 1.2MPa. The monitoring shows that the Re of all branches is ≥4000, realizing the turbulence coordination of the entire branch.

[0067] Step 5: Dynamic closed-loop adjustment. Start all monitoring devices and collect data at a frequency of 1 second / time. After 18 hours of flushing, the oil inlet filter 4 is slightly clogged, causing the pressure of the DN65 branch to drop to 1.8MPa, the flow rate to drop to 92L / min, and Re to drop to 3950 < 4000. The PLC control system adjusts the overflow valve 11 to 2.0MPa within 4 seconds, and then increases the frequency of the variable main oil pump 10 to restore the flow rate to 100L / min and Re to rise to 4920. Other branch parameters are kept stable by fine-tuning the valve opening.

[0068] Step 6: Graded gradient filtration and rinsing.

[0069] 1) Switch the return oil filter 29 to a 10μm filter element, and sequentially complete the single flushing of 3 branches (48 hours per branch) and the initial flushing of all branches combined for 48 hours. The maximum filter pressure difference is 0.12MPa, and no filter element replacement is required.

[0070] 2) Switch to 3μm filter element without shutdown (filtration ratio β=250), and perform fine flushing for 36 hours in the order of single branch and full branch merging. When the filter element pressure difference rises to 0.15MPa after 30 hours of fine flushing, the system prompts to replace the filter element. During the replacement process, the PLC finely adjusts the oil pump frequency and overflow valve 11, and the Re of each branch is maintained at ≥4000.

[0071] 3) The filtered medium is circulated back throughout the entire process, with a media waste rate of only 3%.

[0072] Step 7: Cleanliness acceptance. After fine rinsing, the cleanliness of the oil is tested by an online laser particle counter. The result is NAS1638 Level 5, which meets the Level 6 standard or above, and the rinsing is deemed qualified. The PLC control system shuts down all valves and oil pumps, automatically records all parameters, and generates a turbulent rinsing quality acceptance report.

[0073] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A hydraulic piping turbulent flushing process based on multi-parameter dynamic control, wherein the flushing pipeline is constructed relying on the main components of the hydraulic system, characterized in that, It includes only two modes: single-branch flushing and combined flushing of all branches. Through its main components, it achieves oil heating, oil supply, independent branch monitoring, and closed-loop regulation, ensuring that each pipeline is in a fully turbulent state with Re≥4000 throughout. Specifically, it includes the following steps: 1) Constructing a Reynolds number-multi-parameter quantitative coupling model and a pipeline turbulence threshold library: With Re≥4000 as the core, a quantitative coupling model is established that includes Reynolds number, pipe velocity, flow rate, pressure, temperature, and medium viscosity. The optimal oil temperature threshold is defined as 40~50℃, the pressure of branches with DN50 and above is ≤2.5MPa, the pressure of branches with DN40 and below is ≤1.5MPa, and the flow rate thresholds for each pipe diameter from DN15 to DN100 are adapted to the Re≥4000 requirement. Parameters of commonly used industrial hydraulic pipelines and anti-wear hydraulic oils are collected to construct a turbulence critical threshold library. 2) Intelligent solution for optimal matching parameters of turbulence in each branch and the entire branch: Based on the actual parameters of the branch to be flushed, the basic data is retrieved from the threshold library and input into the model. With Re≥4000 as a hard constraint and the goal of maximizing turbulence intensity and minimizing pressure loss, the particle swarm optimization algorithm or genetic algorithm is used to find the optimal parameters and output the exclusive optimal flow and pressure parameters of each branch and the entire branch. 3) A closed-loop flushing pipeline is built based on the main body components: The oil in the tank (1) is heated as a whole by the electronic heater (5). The oil from the tank (1) is connected to the main oil inlet pipeline (8) through the oil inlet filter (4) and the variable main oil pump (10). After passing through the ball valve (9) and the overflow valve (11), the oil is divided into branches for pressure replenishment. After merging, it is connected to each hydraulic branch (23) through the main oil inlet pipeline (18) and the electromagnetic reversing valve (19). Each branch is independently equipped with a pressure sensor (30), a flow sensor (31), and a temperature sensor (17). The oil from all branches is collected into the main return oil pipe (24). After passing through the return oil filter (29), the drain valve (26), the drain pipe (27), and the drain port (28), the oil flows back to the tank (1) to form a closed-loop flushing pipeline. The tank (1) is equipped with a temperature gauge (6) to monitor the oil temperature. 4) Implementation of single branch and combined turbulence control: First, complete the single branch turbulence flushing, and then realize the combined turbulence coordinated flushing of the entire branch. Through the linkage adjustment of electromagnetic reversing valve (19) with variable main oil pump (10) and adjustable booster pump (13), ensure that each branch obtains matching flow and pressure parameters during single branch and combined flushing, and maintain Re≥4000; 5) Independent monitoring of branches and millisecond-level dynamic closed-loop regulation: Data is collected at a frequency of ≤1 second through the pressure sensor (30), flow sensor (31), temperature sensor (17) and matching Reynolds number monitor of each branch. When the parameters deviate from the threshold or Re < 4000, the control system completes the parameter correction within 5 seconds by adjusting the variable main oil pump (10), adjustable booster pump (13), overflow valve (11) and electronic heater (5) to ensure turbulence throughout the process; 6) Graded gradient filtration and circulation flushing under turbulent conditions: Under the premise of maintaining complete turbulence, the initial flushing of 10μm precision for 48 hours and the fine flushing of 3μm precision for 24~48 hours are completed through the return oil filter (29) in the order of first single branch and then all branches are merged. During the filtration and filter element replacement process, the parameters are finely adjusted to maintain the turbulence without interruption. 7) Turbulent flushing effect acceptance: The cleanliness of the oil is detected by an online laser particle counter. If it reaches the quality level corresponding to NAS1638, it is considered qualified. If it does not meet the standard, turbulent flushing is maintained and the flushing continues. After acceptance, the parameters of the whole process are automatically recorded to form a quality acceptance report.

2. The process according to claim 1, characterized in that, The specific connection route of the closed-loop flushing pipeline mentioned in step 3) is as follows: oil tank (1), oil inlet filter (4), variable main oil pump (10), main oil inlet pipeline (8), ball valve (9), overflow valve (11), divided into two routes: one route goes through the booster pipeline (12), adjustable booster pump (13), and check valve (15), and the other route goes directly through check valve (15). After the two routes merge, they pass through the flow meter (14), pressure gauge (16), and main oil inlet pipeline (18) in sequence. The main oil inlet pipeline (18) passes through the solenoid directional valve (19). Each hydraulic branch (23) is connected to a short pipe (22) and the actuator (21) is connected to a short pipe. All hydraulic branches (23) are connected to the main return oil pipe (24), which then flows through the return oil filter (29), drain valve (26), drain pipe (27), and drain port (28) in sequence, and finally flows back to the oil tank (1). The electronic heater (5) directly heats the oil in the oil tank (1) at a constant temperature. The vent cap (7), level gauge (3), and temperature gauge (6) are all located in the oil tank (1). The oil temperature is monitored by the temperature gauge (6).

3. The process according to claim 1, characterized in that, The specific steps for implementing single-branch and full-branch combined turbulence control as described in step 4) are as follows: 1) Single branch flushing: Close all other branch solenoid directional valves (19), open only the target branch solenoid directional valve (19), adjust the variable main oil pump (10) to the optimal parameters of the branch, ensure Re≥4000, and complete the single branch flushing of all branches in sequence. 2) Combined flushing of all branches: Simultaneously open the solenoid directional valves (19) of all branches, the variable main oil pump (10) provides the basic flow, the adjustable booster oil pump (13) provides additional pressure, and the opening degree of each branch solenoid directional valve (19) is independently adjusted to achieve the optimal parameters of flow and pressure matching of each branch, ensuring that Re≥4000 for all branches.

4. The process according to claim 1, characterized in that, The particle swarm optimization algorithm has a learning factor of 1.5~2.0 and an inertia weight of 0.6~0.

9. The genetic algorithm has a crossover probability of 0.6~0.8 and a mutation probability of 0.01~0.

05. The optimal parameters output by the algorithm have a resistance to fluctuations of ±10%. After fluctuations, the Reynolds number of each branch is still ≥4000. The sampling accuracies of the pressure sensor (30), flow sensor (31), and temperature sensor (17) of each hydraulic branch (23) are ±0.02MPa, ±0.5L / min, and ±0.5℃, respectively. The sampling accuracy of the Reynolds number monitor is ±30Re.

5. The process according to claim 1, characterized in that, The return oil filter (29) is a switchable dual filter element structure. The 10μm initial flushing filter has a dirt holding capacity of ≥100g, and the 3μm fine flushing filter has a filtration ratio β of ≥200. The filter is equipped with a differential pressure monitoring device. When the differential pressure is ≥0.15MPa, the system will automatically prompt to replace the filter element. During the replacement process, the variable main oil pump (10), the variable booster pump (13) frequency conversion frequency and the overflow valve (11) opening are adjusted to compensate for pressure and flow changes and ensure that the turbulent state of each branch is not interrupted.

6. The process according to claim 1, characterized in that, The specific logic of the millisecond-level dynamic closed-loop adjustment is as follows: 1) Re < 4000 and insufficient flow: Increase the frequency of the variable main oil pump (10) or the adjustable booster pump (13) to increase the flow of the corresponding branch; 2) Re < 4000 and pressure is insufficient: First adjust the relief valve (11) to increase the system pressure, and then fine-tune the oil pump frequency to match the flow threshold; 3) Re < 4000 and oil temperature < 40℃: Start the electronic heater (5) to heat the oil in the oil tank (1), and monitor the oil temperature through the temperature gauge (6) until it rises back to 40~50℃; 4) Deviation of single branch parameters during combined flushing: Independently adjust the opening of the solenoid directional valve (19) of the branch to achieve accurate correction of single branch parameters without changing the main oil supply parameters.

7. The process according to claim 1, characterized in that, The core formula of the quantization coupling model is: 1) Reynolds number formula: Re = v·d / ν; 2) Flow rate to velocity conversion formula: Q=v×πd² / 4×60×1000; 3) Formula for friction loss: ΔP =λ·(L / d)·(ρv² / 2), where λ=0.3164 / Re^0.25; 4) Flushing power matching formula: P = Q·ΔP / (60η), where η is 0.75~0.85; all formula calculation results meet Re≥4000 and the requirements of oil temperature, pressure and flow rate thresholds.

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