Search Results (132)

Deep drilling and horizontal wells, as important means of unconventional oil and gas development, face problems with the high energy consumption but low removal efficiency of traditional well washing equipment, the uneven cleaning of horizontal well intervals, and an insufficient degree of automation. This paper proposes a novel hydraulic drive well washing device which consists of two main units. The wellbore cleaning unit comprises a hydraulic drive cutting–flushing module, a well cleaning mode-switching module, and a filter storage module. The unit uses hydraulic and mechanical forces to perform combined cleaning to prevent mud and sand from settling. By controlling the flow direction of the well washing fluid, it can directly switch between normal and reverse washing modes in the downhole area, and at the same time, it can control the working state of corresponding modules. The assembly control unit includes the chain lifting module and the arm assembly module, which can lift and move the device through the chain structure, allow for the rapid assembly of equipment through the use of a mechanical arm, and protect the reliability of equipment through the use of a centering structure. The device converts some of the hydraulic power into mechanical force, effectively improving cleaning and plugging removal efficiency, prolonging the downhole continuous working time of equipment, reducing manual operation requirements, and comprehensively improving cleaning efficiency and energy utilization efficiency. Full article

Electric submersible pumps (ESPs) are critical for artificial lift operations; however, they are prone to frequent failures, often resulting in high operational costs and production downtime. Traditional ESP failure classifications are limited by lack of standardization and the conflation of failure modes with root causes. To address these limitations, this study proposes a new two-step integrated failure modes and root cause (IFMRC) classification system. The new framework clearly distinguishes between failure modes and root causes, providing a systematic, structured approach that enhances fault diagnosis and failure analysis and can lead to better failure prevention strategies. This methodology was validated using a case study of over 4000 ESP installations. The data came from Egypt’s Western Desert, covering a decade of operational data. The sources included ESP databases, workover records, and detailed failure investigation (DIFA) reports. The failure modes were categorized into electrical, mechanical, hydraulic, chemical, and operational types, while root causes were linked to environmental, design, operational, and equipment factors. Statistical analysis, in this case study, revealed that motor short circuits, low flow conditions, and cable short circuits were the most frequent failure modes, with excessive heat, scale deposition, and electrical grounding faults being the dominant root causes. This study underscores the importance of accurate root cause failure classification, robust data acquisition, and expanded failure diagnostics to improve ESP reliability. The proposed IFMRC framework addresses limitations in conventional taxonomies and facilitates ongoing enhancement of ESP design, operation, and maintenance in complex field conditions. Full article

Fuel electro-hydraulic servo valves are core components in the fuel control system of aero-engines, and their performance directly affects thrust regulation and power output precision. Due to the combustibility of the working medium in fuel systems and the lack of effective circulation filtration, the retention of micron-sized particles within the valve gap can lead to valve spool jamming, which is a critical reliability issue. This study, based on fractal theory and the liquid–solid two-phase flow model, proposes a parametric model for non-ideal surface valve gaps and analyzes the dynamics of particles subjected to drag, lift, and buoyant forces on rough surfaces. By numerically analyzing flow field models with different roughness levels and comparing them with an ideal smooth gap model, the migration characteristics of particles were studied. To verify the accuracy of the model, an upscaled experimental setup was built based on similarity theory, and PIV experiments were conducted for validation. Experimental results show that the particle release position and valve surface roughness significantly affect particle migration time. The weight of the release position on particle migration time is 63%, while the impact of valve surface roughness is 37%. In models with different roughness levels, the particle migration time increases more rapidly for roughness values greater than Ra0.4, while for values less than Ra0.4, the increase in migration time is slower. Furthermore, the study reveals that particle migration trajectories are independent of flow velocity, with velocity only affecting particle migration time. This research provides theoretical support for enhancing the reliability of fuel electro-hydraulic servo valves and offers a new perspective for the design of highly reliable hydraulic components. Full article

Electric forklifts are increasingly adopted in industrial environments due to their energy efficiency, reduced emissions, and lower operating noise compared to combustion alternatives. This paper presents a novel methodology for estimating the transported load weight in electric forklifts based on the output power signal of the DC–DC converter driving the electro-hydraulic lifting system. The proposed method leverages non-intrusive measurements of voltage and current to compute the lifting power, lifting speed, and energy, also allowing the computation of the lifting efficiency. The analysis confirmed that lifting energy is not linearly correlated with transported weight but lifting efficiency can be reasonably approximated as a function of lifting power and lifting speed, subsequently allowing the estimation of the transported mass. Experimental validation using 53 lifting events demonstrated that the methodology can estimate load weight with a reasonable mean absolute percentage error of 10.6% and 6.4% when using linear or multivariable regression analysis, respectively. These results demonstrate that the approach is sufficiently accurate for practical applications such as triggering load warnings when the estimated mass exceeds predefined safety thresholds. Full article

Elevators serve as essential vertical transportation systems for both passengers and heavy loads in modern buildings. Electromechanical lifts have become the dominant choice due to their performance advantages over hydraulic systems. A critical component of their drive mechanism is the Permanent Magnet Synchronous Motor (PMSM), which is subject to mechanical and electrical stress during continuous operation. This necessitates advanced monitoring techniques to ensure safety, system reliability, and reduced maintenance costs. In this study, a fault-tolerant PMSM is designed and evaluated through 2D Finite Element Analysis (FEA), optimizing key electromagnetic parameters. The design is validated through experimental testing on a real elevator setup, capturing operational data under various loading conditions. These signals are preprocessed and analyzed using advanced machine-learning techniques, specifically a Random Forest classifier, to distinguish between Normal, Marginal, and Critical states of motor health. The model achieved a classification accuracy of 94%, demonstrating high precision in predictive maintenance capabilities. The results confirm that integrating a fault-tolerant PMSM design with real-time data analytics offers a reliable solution for early fault detection, minimizing downtime and enhancing elevator safety. Full article

Objectives: This retrospective study aimed to evaluate the increase in vertical bone height following sinus lift procedures using the CAS (Crestal Approach Sinus) kit technique in combination with tissue-level implants. Additionally, the quantity of bone between the implant apex and the Schneiderian membrane was assessed to determine the effectiveness and safety of this minimally invasive approach. Methods: The study included 15 patients (20 implants) who underwent sinus lift procedures with the CAS kit technique and tissue-level implants in the posterior maxilla between September 2021 and October 2024. Inclusion criteria required a minimum residual bone height (RBH) of 2 mm. Cone-beam computed tomography (CBCT) scans were used for initial screening, and panoramic radiography evaluated outcomes at implant placement and nine months postoperatively. Primary outcomes included implant and prosthetic survival rates, as well as biological and technical complications. Secondary outcomes were vertical bone height and the amount of bone above the implant tip. Statistical analyses were conducted using the Wilcoxon signed-rank test with a significance level of 0.05. Results: All implants achieved successful osseointegration, with no implant or prosthetic failures and no biological or technical complications reported. The mean RBH at implant placement was 4.2 ± 1.4 mm, which increased to an overall membrane elevation of 13.8 ± 1.8 mm. At the 9-month follow-up, the overall membrane elevation was slightly reduced to 13.0 ± 1.6 mm (p = 0.000), with a mean bone gain of 9.6 ± 2.4 mm. The amount of bone above the implant tip was 3.4 ± 1.7 mm at placement, decreasing to 3.0 ± 1.2 mm at follow-up (p = 0.007). Conclusions: The CAS kit technique combined with tissue-level implants demonstrated significant vertical bone gain and high implant survival rates without complications. This minimally invasive approach proved effective and safe for sinus augmentation in patients with limited residual bone height. The findings support the CAS kit’s potential as a preferred technique for maxillary sinus elevation. Further research with larger cohorts and long-term follow-up is needed to validate these results. Full article

This article addresses the current issue of energy consumption in the hydraulic drive systems of working machines, with particular emphasis on elevators. This paper describes the results of experimental comparative research and estimation of energy and time consumption for two drive systems of a hydraulic indirect elevator. The purpose of this article is to compare the energy consumption of a typical multi-valve system (MV) system with that of an innovative new electro-hydraulic drive (EHD) system with a variable speed pump. The EHD system uses a frequency converter with an energy recovery module to control the speed of the car in both directions and the return of potential energy during the lowering cycle. The comparison of these drive systems was performed under the same conditions, realizing the same elevator work cycles. This paper proposes methods for estimating the energy consumption of an MV system based on measurement data collected during an experiment. The results indicate that the EHD system was less energy-intensive, even at below 60%. The smaller the load mass, the shorter the operating time of the EHD system compared to the MV system. The introduced coefficients defining the energy consumption per unit of mass and payload displacement showed more than twice the decrease in energy demand during lifting and energy recovery possibility during lowering. The EHD system provides the same coefficient values regardless of the distance traveled, which makes it a predictable system, in contrast to the MV system, especially during lowering cycles. The benefits of the EHD also include a less complex hydraulic system (elimination of most valves). Full article

Dynamic response characteristics of the passive heave compensator with auxiliary gas bottles are investigated in this paper. A mathematical model of the passive heave compensator is developed which includes mechanics, hydraulics and pneumatics. The key innovation of the proposed model is that the thermodynamic model of gas exchange between the piston accumulator and the gas bottles is derived and discussed. Meanwhile, a one-dimensional model of the pipeline resistance effect is established to calculate the pressure drop across the oil pipeline. The proposed model is used to evaluate the different design parameters of the passive heave compensator for heavy lifting cranes. A study was conducted to investigate the influence of the design parameters on the effectiveness of the passive compensator to reduce the payload displacement. The simulation results indicated that substantial improvement may be possible by careful design parameter selection and optimization. Full article

To explain one of the reasons why two adjacent deep-rooted desert plants can coexist over long periods, mutual water supply between species was investigated. The study focused on δD and δ¹⁸O stable isotopic characteristics of root water and soil water near the roots of Tamarix ramosissima Ledeb. and Alhagi sparsifolia Shap. in the Tarim River Basin in China during the growing season. The direct comparison method and the Mix SIAR model were employed to analyze the water sources of the plants and the contribution rates of each water source. A similarity proportional index was used to assess the hydraulic connections between plant species. The water sources of T. ramosissima and A. sparsifolia were soil water found at depths of 40 to 90 cm and 220 to 300 cm (a total contribution rate of 58.85%) and 130 to 190 and 240 to 300 cm (a total contribution rate of 81.35%) with groundwater depths of 2.5 to 3.0 m, respectively. When the groundwater depth increased to 4 m, the water sources for both T. ramosissima and A. sparsifolia were soil water at depths of 20 to 100 (a contribution rate of 70.60%) and 20 to 120 cm (a contribution rate of 49.60%), respectively. Both A. sparsifolia and T. ramosissima could lift water from deep soil or groundwater for their own growth needs and supply some water to each other, which suggests that desert plants were allowed to achieve mutual benefits and coexistence through hydraulic connections. These results enrich the theoretical understanding of desert plant coexistence and provide a scientific basis for desert vegetation restoration. Full article

In the harvesting operation, the stubble height of the grain is a vital parameter index in the combined harvesting operation; if the stubble is too high or too low, it will directly affect the harvesting quality and the service life of the header. At present, the profiling control system can only control the lift of the header in the vertical direction but not the horizontal direction and the angle of the cutter profiling. This study proposes a contouring control strategy and system for grain harvesting by analyzing the designed contouring adjustment mechanism and simulating the control method and hydraulic system through Amesim2404 software to simulate and analyze the control method and hydraulic system. Finally, different forward speeds of the harvester (5, 7, 9, and 11 km/h) and other cutting heights of the harvester were analyzed based on static and field tests and different stubble heights (100, 150, 200, and 250 mm) on the test indexes. The results of the field test showed that for different operating speeds, the error between the mean value of stubble height and the target value was small, the absolute error was less than 2 mm, the mean value of the coefficient of variation of stubble height was 4.53%, and the mean value of control accuracy is 94%. The developed adaptive control system of the profiled grain header has high precision and stability, which can provide a reference for the all-terrain profiling control technology of the combined harvester header deck. Full article

Bridges positioned near riverbeds experience complex interactions between flow dynamics and structural geometry, significantly affecting hydrodynamic loading and stability. This study analyzes the effect of deck proximity to the bed on pressure distribution and hydrodynamic loading, including drag and lift forces. Experimental tests were conducted in a rectangular channel using a scaled bridge deck model, varying deck positions, flow conditions, and upstream–downstream water depth levels. To the best of the authors’ knowledge, for the first time, a comparative analysis of hydrodynamic loads on bridge decks was conducted using both rigid and deformable granular beds. Pressure distributions on the front, rear, and bottom faces of the deck were measured using transducers sensors. Our findings corroborate that changes in Reynolds number have minimal impact on the deck drag and lift coefficients, under identical submergence conditions, whereas both coefficients decrease with the Froude number for both bed types. More importantly, the analysis of experimental evidence unveiled some interesting aspects pertaining to the physics of the phenomenon, allowing us to provide the following, unprecedented results: (1) lift and drag coefficients significantly decrease with proximity, exhibiting much higher values than those reported in the literature for larger clearance; (2) under identical hydraulic conditions (both upstream and downstream of the deck), drag and lift coefficients are significantly amplified by the presence of rigid beds compared to granular beds; and (3) the scour evolution alters the effective deck proximity, resulting in time-dependent hydrodynamic loads acting on the deck. Full article

Crawler cranes are mobile lifting equipment used in the process of hoisting goods. After the initial lifting, the crane may need a secondary lift due to adjustments in the position or height of the load. Addressing the common issue of load slipping during the secondary lift caused by hydraulic motor reversal, this study proposes a control strategy applicable to crawler crane secondary lifting. Initially establishing the dynamic characteristics of the secondary lift system, incorporating a delay coefficient, and matching motor pressure build-up with memory pressure, the strategy considers a variable pump input current control to identify the relationship between motor pressure build-up and brake release. Analyzing the dynamic characteristics of secondary lifting under different conditions, this study resolves the issue of hydraulic motor reversal during the second lift caused by heavy loads. The results of this study on crawler crane secondary lifting indicate that, when using a delay coefficient of 0.70 and releasing the brake, no slip phenomenon occurred during the secondary lift process under different load conditions, categorized as 200 tons, 600 tons, and 1000 tons. This ensures the stability and transition quality of the secondary lift, providing theoretical guidance for the control of the crawler crane secondary lifting. Full article

To address vibration issues in the operation of a lift-type power catwalk, dynamic analysis was conducted using ADAMS 2020 software. The analysis revealed that the vibrations originate from collisions that occur during the transition from the translation to the climbing phase. A quantitative vibration model was developed using the work–energy theorem, incorporating the coefficient of restitution. Based on this model, a composite disturbance rejection control law was designed, integrating sliding-mode speed planning with active disturbance rejection speed tracking. The MATLAB 2022b/Simulink simulations demonstrated that the ADRC strategy outperforms PID and DDPG control algorithms in terms of robustness. Co-simulation with ADAMS and MATLAB/Simulink confirmed the effectiveness of sliding mode speed planning, resulting in a 13.54% increase in the transport efficiency of lift-type power catwalks for drill pipes. Additionally, the oscillation of the output speed of the electro-hydraulic servo system at the collision point was reduced by 300% and the displacement, velocity, and acceleration fluctuations in the catwalk’s mechanical system were reduced by 85%, 75%, and 90%, respectively. The experiments on a lift-type power catwalk prototype confirmed that the proposed vibration suppression strategy effectively reduces vibrations. Full article

Symmetric lateral inlet pumping stations are commonly utilized for water lifting in agricultural multi-crop irrigation districts, but they often share non-ideal flow patterns, which can easily cause pump vibration and sediment deposition. In this paper, a symmetrical lateral pumping station in an irrigation district is taken as the research object, and CFD (Computational Fluid Dynamics) technology is used to study it. The model test used a model scale ratio of ${\lambda }_L$ = 1:18. Results: By comparing the CFD data and test data, the average relative error for the left station is found to be 3.213%, while that for the right station is 5.107%, indicating that the numerical simulation method is reliable. Six different rectification measures are proposed, the cross sectional flow pattern of the pumping station is observed, and the longitudinal profile of axial velocity distribution in the sump is analyzed. The velocity-weighted average angle and hydraulic loss of each case study are also analyzed. The flow operates smoothly in case study 7. The vortex in the approach channel disappears when the columns and bottom sill are finally installed. Compared to the original case study, the velocity-weighted average angle at the 5# station in case study 7 increased by 14%, and it increased by 13.9% at station #9. The flow became more stable, and hydraulic losses were minimized. The simulated hydraulic loss in case study 7 decreased by 14.2%. These findings can serve as a reference for similar pump station projects. Full article

The plumes generated during the collection of polymetallic nodules in the deep sea may have a significant impact on the marine ecosystem. Therefore, this article reviews the progress in deep-sea mining and monitoring technologies related to plumes. It is suggested that specific areas of environmental interest (APEIs) and positive altitude characteristic regions (such as seamounts and hills) in the process of polymetallic nodule collection can serve as refuges for benthic organisms and provide a biological basis for the recovery of biodiversity in mining areas. Water-supported vessels, pipeline lifting systems, and hydraulic collection methods are the least disruptive and most promising methods. By sorting out the deep-sea mining process, plumes can be roughly classified into seabed disturbance plumes and tailing plumes. The best way to address plume formation is at the source when developing environmentally friendly mining vehicles. The evaluation of plumes is crucial for the sustainable development of the environment and seabed resources. However, the mechanism is not clear at present. Therefore, laboratory simulation and in situ monitoring need to be coordinated, and attention should be paid to the impact on benthic marine organisms as much as possible during original operations. Plume research in the deep-sea mining process will also provide favorable support for the possible future development of seabed resources. Full article