Automating operations is challenging due to the structural characteristics of the sucker rod. This article proposes an automation approach based on process reconstruction, which includes wellhead positioning, 90-degree flipping of the upper and lower rods, and vertical replacement; alternating between gentle and harsh clamping while using a double sucker rod and elevator guidance system; combining hoisting and clamping through the elevator's rotary action on the flange and core; enabling simultaneous operations and process improvements; and visible master/slave control. Using the sucker rod as an example to split the process path, Gantt chart analysis is used to propose improvement measures. The completion of the on-site prototype manufacturing application demonstrates the practicality of both the equipment and process, as well as a significant increase in operational efficiency compared to manual methods. This technology leads the development of automation in minor workover operations and makes the non-landing operation mode of vehicle-mounted root box pipe poles feasible.

Lotus root possesses a unique internal cavity structure. Accurately determining its mechanical properties is essential for optimizing postharvest handling equipment and reducing mechanical damage. This study aimed to determine the apparent elastic modulus of lotus root and evaluate the effectiveness of Hooke’s law and Hertz’s theory in predicting its overall mechanical behavior through finite element analysis. A three-dimensional lotus root model incorporating the internal cavity structure was reconstructed using reverse engineering techniques. Three finite element models were established: cylindrical specimen model, lotus root segment model, and intact lotus root model. The results showed that lotus root tissue exhibits significant mechanical anisotropy (p < .01), while inter-individual variability is the primary source of variation in the elastic modulus. Under spherical probe compression, lotus root sustained damage at a load of 90.7 N, with a corresponding deformation of 2.09 mm. Under flat plate compression, the minimum rupture force of lotus root was 578.7 N, with a corresponding deformation of 5.49 mm. The apparent elastic modulus determined from intact lotus root model compression tests was 8.22 MPa. Among the three finite element models, the intact lotus root model achieved the highest prediction accuracy, with a compressive force error of 16.24%, significantly outperforming the cylindrical specimen model (56.15%) and the root segment model (37.22%).

Based on the independently developed water jet experimental platform, experiments and numerical studies were conducted on the inclined jet erosion of cohesive soil under different jet velocities (U0), inclination angles (θ), and target distances (h) to reveal the dynamic evolution characteristics of the three-dimensional flow field inside the erosion hole. A physical model for cohesive soil jet scouring was established, in which the Bingham rheological parameters were incorporated into the solver via User-Defined Function (UDF), and the Volume of Fluid (VOF) method was employed to track the evolution of the water–soil interface. Experimental results indicate that, with increasing θ, the scour hole morphology gradually transforms from “deep and narrow” to “shallow and wide,” accompanied by a significant reduction in sediment accumulation and a marked enhancement in inner-wall stability. The maximum scour depth ( ε_m ), radius ( r_m ), and volume ( ξ ) increase markedly with increasing U₀. When θ = 30°, the scour hole length and volume reach their maximum values, with r_m = 832 mm and √(ξ) = 511 mm, respectively. Whereas the maximum scour depth ε_m = 590 mm is obtained at θ = 22.5°. The erosion process induced by the inclined jet can be divided into three stages: initial impingement, unstable expansion, and dynamic equilibrium, during which the scour hole morphology evolves from an elliptical shape to a wing-like pattern and ultimately develops into a stable scour hole. On this basis, a dimensionless scouring equation for predicting the equilibrium scour depth was established by combining theoretical analysis with experimental data. The scour depth exhibits a logarithmic growth with dimensionless time. This study provides important guidance for optimizing subsea pipeline installation and improving the efficiency of dredging operations.

Global climate change has triggered frequent extreme weather events, leading to a significant increase in the frequency and intensity of forest fires. Traditional fire monitoring methods such as manual inspections, sensor technologies, and remote sensing satellites have limitations. With the advancement of drone technology and deep learning, using drones combined with artificial intelligence for fire monitoring has become mainstream. This paper proposes an improved YOLOv8-based model that incorporates local convolution instead of full convolution in the C2F module and integrates the EMA module to enhance the feature channel interaction modeling capability and contextual information utilization, thereby reducing model complexity and increasing efficiency. Additionally, in order to address the risk of false positives and missed detections caused by vegetation, terrain, and lighting changes in forests, we have introduced the AgentAttention module in the Backbone. This module combines Softmax and linear attention to optimize feature extraction, improving the model’s accuracy and robustness. Furthermore, in order to tackle the challenges of detecting flames and smoke at different scales and angles, we have designed the BiFormer module, which adaptively fuses global and local features, significantly enhancing the model’s multi-scale and multi-angle detection capability. Experimental results show that the improved model achieves Precision and Recall of 93.57% and 88.51%, respectively, representing improvements of 5.05% and 2.72% over the original model. It also optimizes FPS, GFLOPs, and Params by 14.3%, 25%, and 19.7%, respectively. This research has significant application prospects in forest fire early warning, emergency response, and loss reduction, while also providing strong technical support for forest resource protection and public safety.

Jet erosion is a frequent occurrence in maritime engineering and in river erosion. This study was based on a self-developed water jet experimental platform, and conducted experimental and simulation studies on the vertical jet erosion of cohesive soil under different velocities ( U_0 ) and target distances (h). To describe in detail the three-dimensional dynamic changes in the soil jet scouring hole. Build a custom function (UDF) model for soil erosion, embed the experimentally measured Bingham rheological model parameters into the solver, and combine them with the Krieger–Dougherty model to determine the threshold of ϕ_c = 0.35 for the soil initiation volume on the iso-surface during the simulation process. According to the dynamic size changes of the simulated jet scouring holes, jet scouring is divided into four stages: initial stage, expansion stage, unstable expansion stage, and stable development stage. The experimental data for jet erosion holes is fitted, and dimensionless equations ε_m∞ , √(ξ) , and r_0∞ for viscous soil erosion holes under equilibrium erosion conditions are proposed, with a correlation coefficient of 0.94, 0.90 and 0.91. By comparing the simulation and experimental data, it was found that the scour hole depth developed logarithmically with dimensionless time, further verifying the effectiveness of the simulation model.

To investigate the connection between nozzle jet performance and structural characteristics (contraction angle θ, outlet diameter d, ratio of straight segment to outlet diameter L2/d), impact force studies were performed on nine nozzles with varied structures using a self-developed water jet experimental platform, with target distances of 20mm, 100 mm, 200 mm, and 300 mm with jet pressures of 0.1 MPa, 0.2 MPa, and 0.3 MPa. The impact force of a nozzle water jet grows dramatically as the outlet diameter increases. When the pressure of the water jet remains constant, the impact force increases as the target distance increases. The maximum water jet impact force is 6.1 KG when the d is 11 mm. The BP neural network, the PSO and the GA-BP neural networks were utilized to forecast and assess the nozzle impact force at a target distance of 300 mm, respectively. The results reveal that, when compared to the PSO and the BP neural network, the GA-BP neural network projected values are more consistent with the measured values, with a lower average error rate and greater predictive capacity.

Abstract Water jet technique is widely used in the dredging of rivers and canals, and has significant engineering value. This work develops the sediment dynamic model to build a velocity-based bed load sediment transport model. The process of low-pressure water jet river bed erosion was investigated at various water jet pressures and nozzle outlet diameters, with the Shields Parameter serving as the sediment initiation threshold. The process of developing a flow scour pit is divided into three key stages: particle triggering, quick development, and dynamic equilibrium. A transient simulation of submerged three-dimensional jet erosion was performed using a mixture model in Fluent software, with the laboratory physical model parameters as reference. The numerical simulation findings that the erosion sand pit characteristic parameters agreed with experimental data, and the particle initiation model was also confirmed. An empirical formula was established based on numerical modeling and experimental data to estimate the characteristic size of the scouring pit during jet erosion equilibrium.

Due to the alternating loads on pumping units and the integration of new energy sources, multisource DC microgrid pumping unit well groups experience increased fluctuations in voltage and power as well as superimposed peak and valley values. This work presents a distributed control strategy for pumping unit well groups on a multisource DC microgrid based on the weighted moving average algorithm. A centralized control program is implanted in the RTU of the single-well controller of each pumping unit, and communication with each well is realized via SCADA and multicast communication, resulting in a distributed well group system. The real-time power values of the pumping well group are calculated by grouping the power values, and each group is weighted using the total power fluctuation threshold of the well group as the control target. Then, a weighted moving average algorithm is used to predict the next power value and form a table of predicted real-time power spectra. According to the power values in the community power spectrum table, the inverter frequency is proportionally adjusted downwards to reach the power peak before deceleration; after the power peak is crossed, the frequency is increased in the same way to reach the power valley before acceleration. Finally, the peak and valley power values of the bus system level off and further learn to reach the set impulse; ultimately, a stable impulse is formed. In laboratory testing and field application in the Shengli Oilfield XIN-11 block, the group control software module effectively suppressed the active power peak and valley values and voltage fluctuations of the bus system, the active power fluctuation rate range decreased by more than 70%, and the DC bus voltage fluctuation range decreased by more than 80%; moreover, the active power decreased by approximately 6% without additional hardware costs.

The bionic nozzle was designed based on earthworms' non-smooth surface structure and the properties of auxiliary jet holes. The drag reduction mechanism and hydraulic characteristics of convex structure-auxiliary jet hole inner wall nozzle (SG), convex structure inner wall nozzle (VS), concave structure inner wall nozzle (CS), and smooth inner wall nozzle (S) were simulated and analyzed using computational fluid dynamics (CFD). The simulation results show that the maximum instantaneous velocities of the four nozzles are SG (29.2 m/s) > VS (28.79 m/s) > CS (28.55 m/s) > S (28.35 m/s). The biomimetic nozzle's convex structure generates a reverse velocity field, and this causes the low-speed fluid to cluster along the vertical direction of the jet, generating a low-speed turbulent band and enabling the low-speed field to constantly rise toward the jet's center area, thus reducing fluid resistance. The auxiliary jet holes can further reduce the intensity of turbulent processes and achieve the goal of reducing drag. Therefore, the SG-shape has the most significant drag reduction effect. Based on the coupling of CFD and finite element analysis (FEA), the relationship between input parameters (auxiliary jet hole diameter P1, convex structure diameter P2, and auxiliary jet hole length P3) and output response (maximum principal elastic strain and maximum principal stress) was determined. Response surface methodology was used to optimize P1, P2, and P3 parameters of SG-shape, resulting in the optimal combination of P1 = 1.45 mm, P2 = 2.71 mm, and P3 = 9.27 mm. Through CFD simulation and water jet impact test verification, the maximum velocity of the optimized biomimetic nozzle is 31.2 m/s, which is 6.8% higher than before optimization. The maximum impact force generated by the optimized water jet is 8.61 KG, a significant increase of 7.5% compared to before optimization.

A fully hydraulic intelligent lotus root harvester has been designed to solve the difficult problem in the harsh muddy water environment of the lotus pond. Power distribution is achieved through proportional hydraulic pumps, proportional speed control valves, directional valves, and low speed high torque motors, Forward and reverse control and hydraulic flow adjustment to achieve speed changes such as forward, backward, and turning of the machine. Accurately regulate speed and direction to meet the walking and transition requirements of Lotus Pond; Innovatively designed a chassis structure with the core of “wide rubber track +buoyancy box+ four point linkage lifting device”, which can adapt to different operating water depths; Hydraulic, pneumatic, and electric joint control, Realize remote control of low-pressure and high flow jet, The chain reversing and swinging mechanism integrates chain reversing, lifting, and jetting to achieve swinging jetting, Dynamically adjusting the distance between the jet unit and the mud surface, Vigorously improving the efficiency of low-pressure and high-flow jet.

Abstract Due to the pumping units' dual role as alternating loads and new energy sources, multi-source DC microgrid pumping unit well clusters experience increased fluctuation in voltage and power as well as peak and valley values that are superimposed. This work presents a distributed cooperation strategy based on the grouping weighted moving average algorithm for pumping unit well groups in multi-source DC microgrid. Centralized control program is implanted in the RTU of the single well controller of each pumping unit, and the communication of each single well is realized by SCADA system to construct the distributed well group system. The real-time power values of the pumping well group are calculated by grouping the power values and granting weighted weights to each group, using the total power fluctuation threshold of the well group as the control target, and further using a weighted moving average algorithm to predict the next power value and form a table of predicted real-time power spectra. According to the power value in the community power spectrum table, the inverter frequency is proportionally adjusted downward to achieve the power peak before deceleration to reach; after crossing the power peak, the frequency is raised in the same way to accelerate the compensation to achieve the power valley before acceleration to reach, that is, acceleration compensation, and finally achieve the power peak and valley values of the bus system to level off, and further learn to reach the set impulse, and finally form a stable impulse. Through laboratory testing and field application in Shengli XIN-11 block application proved: the group control software module not only effectively suppresses the active power peak and valley values and voltage fluctuations of the bus system, the active power fluctuation rate range decreases by more than 70%, the DC bus voltage fluctuation range decreases by more than 80%, but also reduces active power by about 6% without increasing the cost of new hardware.

Nitrogen is already widely used in pipeline replacement and other related processes in the operations of LNG/LPG and offshore platforms. Now, it is being applied to processes in deep-water operations as well. In the paper, skid-mounted PSA nitrogen generation modules using high-pressure, high-purity tube bundles were designed and developed for application on offshore platforms. Firstly, the special requirements of offshore platforms for nitrogen production modules, such as high pressure and high purity and certification, are analyzed, and key technical difficulties are identified. Integrated tube bundle modules were used to design the PSA nitrogen reaction tower and pressure vessel, which effectively avoided certification difficulties and reduced costs. The proposed equipment was combined with a high-pressure molecular sieve for experimental research. A carbon molecular sieve (CMS) with pressure up to 1.7 MPa was selected, which exceeded that of mainstream CMSs (0.6-0.8 MPa). For the control scheme, an overlapping start-up mode was adopted for compiling the control program, which is realized through PLC + touch screen implementation + pneumatic control. The entire machine was integrated into 3 skid-mounted modules, and the relevant performance tests were carried out after manufacturing was completed. The output pressure was at least 1.4 MPa and the overall indicators met the design requirements. This project had introduced a new design concept and method for the development of skid-mounted high-pressure, high-purity nitrogen generation modules to be used on LNG/LPG and offshore platforms, and especially those modules required for deep-water operations.

为了提高修井作业的自动化程度,提出了"立式接替作业、吊卡不流转"的新型修井作业工艺.立式翻转猫道是该工艺的核心部件.分析了立式翻转猫道的结构组成,建立了简化的力学模型,求解得到液压缸驱动力变化规律,并通过SolidWorks Motion软件分析获得仿真曲线.理论解析与仿真分析结果一致,验证了理论解析的正确性.利用Adams软件对立式翻转猫道进行动力学仿真,得到了翻转运动规律.为立式翻转猫道设计和翻转运动控制提供了理论依据.

In view of the facts that the traditional intangible assets value assessment method is not suitable for the evaluation of technical achievement value, the paper proposes a practical value evaluation method combined with the application of its nation characteristics based on big data analysis. The paper reviews technological achievements characteristics, the determinant factors of the evaluation, evaluation principles and existing problems. Evaluation standard system based on work breakdown structures is made, which is based on a large data query retrieval and mining analysis. Further the paper sets standard of data query and operation specification, and establishments technology achievements assessment network service platform based on the “Internet plus”. The paper offers an illustration of price of technological achievements evaluation auxiliary to the database related technology market price benchmarking value. Finally, through a large number of practical examples, the feasibility and practicability of the method are proved. This paper contributes to value evaluation of technological achievements theoretically and operation in the busilaness managerial implication.

针对单塘面积大、藕塘密集的地区设计了一种作业幅宽为4 m的水射流式莲藕采挖机.由于宽幅挖藕机水管道分支较多,易出现各喷头出水压力不均匀现象,导致莲藕漏采、受损.基于Fluent对挖藕机水管道进行了仿真分析,发现调整喷头间距不能有效降低压力波动,而通过调整喷头出口截面直径可显著改善喷头出水压力均匀性,出水压力波动范围由0.36 MPa降低到0.18 MPa,为宽幅水射流式挖藕机的喷头、射流系统的设计提供了参考.

PurposeThe purpose of this paper is to study the effects of operating conditions including process coefficient, lubricant viscosity and cavitation pressure on the cavitation of spiral groove liquid-film seal (SG-LFS).Design/methodology/approachA mathematical model of SG-LFS is established based on the JFO boundary and a relative density is introduced. The universal governing equation after a coordinate transformation is discretized by the FVM method and solved by the Gauss-Seidel relaxation scheme.FindingsThe results indicate that the two-dimensional size of cavitation and cavitation degree are affected significantly by the process coefficient and lubricant viscosity but the effect of cavitation pressure can be ignored.Originality/valueThe effect mechanisms of operating conditions on the cavitation of SG-LFS are studied by the JFO boundary and cavitation degree characterized by a relative density. The results presented are helpful to perfect and deeply understand the cavitation mechanism of liquid-film seal.Peer reviewThe peer review history for this article is available at:https://publons.com/publon/10.1108/ILT-03-2020-0083/

为探索微观表面形貌对液膜密封空化的影响,基于满足质量守恒的JFO空化模型及坐标变换,建立考虑微观表面形貌的双坝区螺旋槽液膜密封数学模型;采用有限体积法离散求解控制方程,综合分析表面粗糙度、周向波度和径向锥度对螺旋槽液膜密封空化发生的影响规律.结果 表明:相比而言,密封面计入微观表面形貌后,摩擦副液膜中空穴区发生位置分散且形状不规则;以空化面积比为判据,较大表面粗糙度对液膜空化促生虽起到积极作用,但数据较小,可忽略不计;锥度对液膜中空穴促生和抑制影响有限,波幅的增加显著促进液膜中空穴的发生;高频波数时,正锥度有利于降低液膜空化面积比,抑制空穴.

Based on the planetary gear mechanism which realizes the three-leaf rose line drawing method, the ratio of the number of teeth of the sun gear, the planetary gear, the internal gear, and the length of the tracing rod are deduced. The calculation formulas of the number of teeth and the length of the tracing rod for drawing rose lines of any leaf are obtained. SolidWorks is used for modeling and dynamic simulation. The simulation results show that the conclusion is correct.

Continuous circulation valve (CCV) drilling is an important form of continuous circulation drilling (CCD), whose key technology lies in the design of CCV. In this paper, a T-type integrated triple valves is designed and developed, which integrates the by-pass pressure relief valve and the main channel three-way ball valve in the same principal axis section. The CCV can be switched up and down and bypass through manual adjustment mechanism, which achieves the switch between normal circulation drilling and bypass circulation drilling. In order to verify the rationality of the design, ABAQUS software is used to analysis the situation with different tension, pressure, bending, twist, internal pressure and external pressure. The result confirmed that the overall strength met the requirements. So as to analyze the feasibility of manually rotating hexagon wrench to adjust and switch the three-way valve, the maximum torque of T-type three-way valve is discussed by combining simulation analysis and numerical calculation, and the Switch t-type three - way valve can be realized manually. Further simulation verifies that the overall sealing is good of the three-way valve body valve when the three-way valve is opened and closed. The change of the diameter of T-type three-way valve causes the acceleration of liquid flow rate and the increase of mud internal pressure, which has certain iMPact on the three-way body. Generally, the three-way body has no influence on the flow flux of mud in the whole drill pipe. Finally, it is verified through field application that the T-type integrated three-way valve design is reasonable, and the simulation and calculation analysis reach the expected goal.

Safety assessment method of the subsea pipeline under the third?party impact load has not yet reached the extent of application to engineering practice?In order to solve this problem, the finite element method is used for the research on the impact damage of subsea pipeline considering the concrete layer?Based on influences of the factors such as material nonlinearity, geometric nonlinearity and contact interface nonlinearity on structural damage and deformation of the subsea pipeline, a deep analysis is conducted for influences of falling object shape, falling object velocity, falling object mass and concrete layer thickness on plastic deformation of pipeline?The anal?ysis results show that impact damage resistance of the subsea pipeline decreases with increase of concrete layer thickness; among cube, sphere and cone of the falling object, the cone has the most severe impact damage, and the impact damage of the subsea pipeline is proportional to mass and velocity of the falling object?The study results have important reference significance for risk assessment, engineering design and disaster prevention and mitigation of the subsea pipeline.