Enhancement of dynamic performance of wave energy converter by introducing a flow control

The stabilization of power take-off (PTO) is imperative especially under circumstances of fluctuating input wave energy. In this paper, a flow control valve is introduced to optimize the transient process of the hydraulic PTO, which can contribute to a quicker adjustment and a stronger stability. Under variations of input power and load torque in transient process, an open-loop control method and a closed-loop control method are proposed as the opening law of the above valve, and the hydraulic motor speed, the pressure at the accumulator inlet and the generated power are chosen as indicators to examine the regulation performance. Then, the synergic effect of the flow control valve and the accumulator in the transient process is discussed. The effectiveness of the two presented control methods on the fluctuation suppression is respectively tested and compared in both regular wave and irregular wave situations via simulation. To validate the practical effectiveness of the proposed methods, field experiments are conducted. The results demonstrate that the open-loop control can only improve the damping ability of the hydraulic PTO in the speed raising stage, while the closed-loop control can improve the stability both in the speed raising stage and in the load increasing stage.

Agile Smart Completion Application for Effective Water Production Control in Heterogeneous Carbonate Reservoir in Abu Dhabi Offshore Reservoir

This paper provides the learnings from a successful application of a smart completion in a complex heterogeneous carbonate reservoir. It details the study, planning, coordination, and implementation process of two pilot wells by a multidisciplinary team, and pilot production performance results, illustrating the success. First, to select an optimum completion design for the field, multi-segment well option and local grid refinement option were applied to the reservoir simulation model including calibration of faults/fractures. Second, based on the modified model, sensitivity analysis was conducted; 1) by selecting different types of completion including Open-hole, blank pipes (BP), compartmentalized slotted liners (SL), inflow control device (ICD) and hydraulic flow control valve (FCV); 2) by optimizing the number of compartments (packer and blank pipe placements for all cases), and ICD / FCV numbers and nozzle sizes. Using the data from the modeled cases, economic analysis was conducted, which indicated that the ICD in conjunction with sliding sleeves (SSD) was the best option. Two candidate wells were selected to cover the variation of reservoir characteristics: one well representing the heterogeneous part of the reservoir with high-density of faults, fractures and kurst, and another one representing the relatively homogenous part of the reservoir suffering from heel to toe effect. A multidisciplinary implementation team was set up to align all stakeholders on subsurface requirements, following up the completion design, coordinating material procurement and logistics for mobilizations, daily drilling operations follow-up, real-time logging data interpretations and completion design adjustment. Evaluation of the two pilots’ results based on predefined KPIs during the study, exceeded overall expectations.

Control System of a Robotic Irrigation Machine Based on the Mamdani Fuzzy Algorithm

The article analyzes the tasks that can be solved by agricultural robots. The purpose of the study was the robotization of the "Fregat" type crop irrigation machine by the fuzzy control of irrigation technological processes, which allows to control the irrigation rate. It is proposed to use in a robotic irrigation machine the analog valve-setter of the speed of the last cart, powered by electricity. It is recommended to include a diagnostic subsystem in the fuzzy control system of the flow control valve, which includes sensors for measuring the soil moisture and the slope of the irrigation machine in various areas of the field. The mathematical model of fuzzy control of the irrigation machine is developed based on the software control of the water supply depending on the terrain of the field, the speed of irrigation machine and soil moisture to reduce water consumption and improve the efficiency and quality of irrigation. The Mamdani algorithm, which is implemented in the MATLAB package, is proposed as a fuzzy inference system. The formalization of the description of the indicators of the irrigation machine is carried out by specifying linguistic variables. The proposed mathematical model can be used in the design of control systems for other robotic agricultural machines.

Testing and Analysis of Fasteners

By considering the tightening process, the experimental testing will be conducted to explore the mechanism of bolt selfloosening under biaxial loading. The most common mode of failure is overloading: Operating forces of the application produce loads that exceed the clamp load, causing the joint to loosen over time or fail catastrophically. Over torque might cause failure by damaging the threads and deforming the fastener, though this can happen over a very long time. Also, the bolts may fail under fatigue. The components used in the system are bolts, pneumatic cylinder and flow control valve. The pneumatic cylinder is actuated with the help of compressor. The flow of air in the cylinder will be controlled with the help of pneumatic cylinder which will be acted on the bolts in two directions that is from downward & upward direction. This means the load will be tensile and shearing load. The bolts are attached to the plates. Because of actuation of the pneumatic cylinder the bolts will become loose. These bolts will be tested by using biaxial loading. The result & conclusion was drawn after the experimental testing. Keywords: Bi-axial Loading, Fasteners, Bolt Loosening, Residual Torque, Fastener Overloading

Design and Analysis of a Flow-Control Valve With Controllable Pressure Compensation Capability for Mobile Machinery

There are the problems in the traditional pressure-compensation flow-control valve, such as low flow control accuracy, small flow control difficulty, and limited flow range. For this, a method of continuous control pressure drop Δprated (i.e. the pressure drop across the main throttling orifice) to control flow-control valve flow is proposed. The precise control of small flow is realized by reducing the pressure drop Δprated and the flow range is amplified by increasing pressure drop Δprated. At the same time, it can also compensate the flow force to improve the flow control accuracy by regulating the pressure drop Δprated. In the research, the flow-control valve with controllable pressure compensation capability (FVCP) was designed firstly and theoretically analyzed. Then the sub-model model of PPRV and the joint simulation model of the FVCP were established and verified through experiments. Finally, the continuous control characteristics of pressure drop Δprated, the flow characteristics, and flow force compensation were studied. The research results demonstrate that, compared with the traditional flow-control valve, the designed FVCP can adjust the compensation pressure difference in the range of 0∼3.4 MPa in real-time. And the flow rate can be altered within the range of 44%∼136% of the rated flow. By adjusting the compensation pressure difference to compensate the flow force, the flow control accuracy of the multi-way valve is improved, and the flow force compensation effect is obvious.

AIR FLOW CONTROL VALVE DEVELOPMENT WITH REINFORCED OPERATING PARAMETERS

Recent research has shown that particles in the air and harmful gases in the environment increase the risk of various respiratory diseases and mortality rates. For effective ventilation, particles and harmful gases in the environment must be captured before they are released into the environment. Air flow control valves (AFCVs) play an active role in the capture of particles and harmful gases in the environment with central ventilation system. In the study, an innovative AFCV, which is the most critical part of central ventilation systems, has been developed. Performance criteria in the innovative AFCV design have been the capture rate, the flow rate and turbulence intensity. In this study, six valves are designed as an alternative to the current valve. The designed valves were mounted on the central ventilation system hood and numerical analysis was performed. ANSYS Fluent software was used for the analysis. The best and worst valves were determined as a result of numerical analysis. Prototypes of the determined valves were created and experimental verification tests were carried out. Again, numerical analyses simulating the experimental tests were performed with these two valves. The experimental test results and numerical analysis results were compared. As a result, due to the innovative AFCV design, the air flow and the capture speed have been increased and the turbulence intensity has been reduced.

Precision Control of Spraying Quantity Based on Linear Active Disturbance Rejection Control Method

Current methods to control the spraying quantity present several disadvantages, such as poor precision, a long adjustment time, and serious environmental pollution. In this paper, the flow control valve and the linear active disturbance controller (LADRC) were used to control the spraying quantity. Due to the disturbance characteristics in the spraying pipeline during the actual operation, the total disturbance was observed by a linear extended state observer (LESO). A 12 m commercial boom sprayer was used to carry out practical field operation tests after relevant intelligent transformation. The experimental results showed that the LADRC controller adopted in this paper can significantly suppress the disturbance in practical operation under three different operating speeds. Compared with the traditional proportional–integral–differential controller (PID) and an improved PID controller, the response speed of the proposed controller improved by approximately 3~5 s, and the steady-state error accuracy improved by approximately 2~9%.

Water Flow Control Valve

A water flow control valve is very important tool as per mechanical industry. Present invention in general relates to the field of mechanical engineering and more specifically to water flow control valve, which comprises of Y shape pipe and on/off circle ring. Controlling the water flow is not easy task it is time consuming and simultaneously required more labor which is both slow and exhausting task. Also in simple "Y" shape pipe (two different directions), one cannot control the flow or direction in that shape. Thus there is an urgent need to design and develop am improved system or device for controlling the flow of water. Many attempts are made for the same and few of them are discussed below. CN104373661A discloses power-off protection type water flow control valve. A magnet is fixed to a valve rod, a coil can drive the valve rod, which is driven by the magnet, to move vertically in a reciprocating mode, and a control circuit makes the valve be opened or closed through control over the current direction of the coil. Compared with the prior art, the power-off protection type water flow control valve has the advantages of being capable of effectively lowering the using cost of a user, long in service life, capable of performing water flow protection in case of power-off and providing a manual opening and closing function so that using can be not affected for the user even under the power-off condition, reliable in performance, capable of being assembled or manufactured in an integrated mode and convenient to produce; the opening or closing state can be kept without current, and energy consumption is low.

All-Electric Intelligent Completion System: Evolution of Smart Completion

Field D is a mature offshore field located in East Malaysia. A geologically complex field having multiple-stacked reservoirs with lateral and vertical faulted compartments & uncertainty in reservoir connectivity posed a great challenge to improve recovery from the field. Severe pressure depletion below bubble point and unconstrained production from gas cap had contributed to premature shut-ins of more than 50% of strings. As of Dec 2019, the field has produced at a RF less than 20%. Initial wells design consisted of conventional dual strings & straddle packers with sliding sleeves (SSD). Field development team was challenged for a revamp on completion design to enhance economic life of the depleting field. In 2015, as part of Phase-1 development campaign, nine wells including four water injectors were completed initiating secondary recovery through water flood. An approach of Smart completion comprising of permanent downhole monitoring system (PDHMS) and hydraulic controlled downhole chokes or commonly known as flow control valve (FCV) was adopted in all the wells in order to optimize recovery from the field and step towards intervention-less solutions. Seeing the benefits of intelligent completion in Phase-1, Phase-2, drilled and completed in 2019 – 2020 has been equipped with new technology "All-electric Intelligent Completion System" in 4 out of 8 oil producers. The new design addresses the reservoir complexity, formation pressure and production challenges and substantial cost optimization, phasing out the load of high OPEX to CAPEX. Installation of "All-electric Intelligent Completion System" has proven to be an efficient system compared to hydraulic smart completions system. It requires 50% to 75% less installation time per zone and downhole FCV shifting time is less than five minutes compared to several hours full cycle for hydraulic system. The new system has capability to complete up to 27 zones per well with single cable. It gave more options and flexibility in order to selectively complete more zones compared to hydraulic FCVs which requires individual control line for each zone. Future behind casing opportunities (BCO) have been addressed upfront, saving millions of future investment on rig-less intervention. In addition to that, non-associated gas (NAG) zones have been completed to initiate in-situ gaslift as and when required avoiding the dependency on aging gaslift facility. The scope of the paper is to show case the well design evolution during Field D development and highlight on how smart completion has evolved from original dual completion to hydraulic smart and recently to electric smart system, how it has contributed to cost and production optimization during installation and production life and also support the gradual digitalization of the Field D. In the end it demonstrates the optimized completion design to enhance the overall economic life of the depleting field.