Piston Diameter Research Articles

Low-Force Shear Blades Developed for High-Strength Coiled Tubing

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 204403, “Development of Low-Force Shear Blades for High-Strength Coiled Tubing,” by Scott Sherman, Nexus Energy Technologies, prepared for the 2021 SPE/ICoTA Virtual Well Intervention Conference, 22–25 March. The paper has not been peer reviewed. As coiled tubing (CT) grades have evolved during the past 20 years and wall thicknesses have increased, the resulting force required to shear coil has more than doubled. An industry need existed to develop a shear blade for blowout preventers (BOPs) that could cut high-strength CT using legacy pressure-control equipment already in use. The paper describes the iterative process of development of a novel shear blade able to cut high-strength CT with 50% of the normal shear force. Objective The objective of the work detailed in the complete paper was to develop a novel CT-shearing system capable of cutting high-strength heavy-wall CT with reduced hydraulic pressures. Considering that CT will continue to evolve in terms of yield strength, the goal of the study was to future-proof BOPs wherever possible to protect customers from the liability of obsolete equipment. The authors write that, ultimately, BOPs will need to cut 175-grade CT strings with a 7-mm wall thickness with 103 MPa of wellbore pressure and less than 17.2 MPa hydraulic pressure. Development Process Initially, the following five options were considered: - Larger-diameter cylinders. This seemingly simple option, which would generate more shear force, was ruled out because the implementation would not be backward-compatible with existing well-control equipment and the larger cylinder volume would result in slower cycle times. - Boosted actuators. These could double shear force while maintaining piston diameter. While this solution is simple, theoretically, these actuators require twice as much hydraulic fluid from the accumulator to function. This results in a closing time that is nearly double that of a nonboosted actuator. - Pressure-balanced actuators. With this option, hydraulic forces would not need to overcome the forces related to wellbore pressure in addition to providing sufficient force to shear CT. These actuators do increase the amount of shear force available to cut CT when used on high-pressure wells. However, they increase complexity, cost, and weight and could result in trapped wellbore fluids within the actuator that could lead to corrosion-related issues. - Increasing hydraulic pressure to a given set of rams using a pressure multiplier for the shear rams or a similar system. This solution was deemed unsuitable because the hydraulics of most BOPs are designed for 150% of their rated pressure. Doubling the hydraulic pressure available to the BOP could damage the hydraulic cylinders and associated actuators, resulting in a catastrophic well-control situation. - Modifying shear blade geometry to reduce the shear force needed to cut CT using existing equipment. This was selected as the most-logical approach because the modified shear blades could be retrofitted into existing BOPs. Furthermore, this solution would not require modification to existing wellsite equipment such as accumulator skids and would not increase the weight or size of the BOP stack.

Mathematical model of a single-acting pneumatic cylinder actuator

Pneumatic actuators are widely used in industry as the most reliable automation tools. The efficiency of automated systems depends on the speed of pneumatic actuators. Therefore, the development of methods studying the dynamic processes of pneumatic actuators is an urgent task. this paper concerns a mathematical model of a single-acting pneumatic cylinder actuator, which is convenient for computer calculations using universal mathematical packages. As an example of the application of a mathematical model, paper shows the influence of the piston diameter on transient processes in a pneumatic actuator.

Studying a low-temperature engine with external heat supply

The article presents some results of studying the most optimal parameters of the displacer and the piston of a low-temperature engine with external heat supply to increase its efficiency when converting low-grade heat. The developed design of the engine does not have a displacer rod, which provides better sealing and reduces mechanical friction losses. Synchronization of the piston and the displacer movement is ensured by the permanent magnets interaction. The analysis of the results of computer simulation of the PV diagram with an increased diameter of the displacer in relation to the piston diameter plays a positive role in increasing the efficiency and power of the engine. Increasing the diameter of the displacer also leads to increasing the area of the PV diagram and its approach to the ideal thermal Stirling cycle. The simulation results show that increasing the diameter of the displacer above 17/1 does not lead to increasing the area of the PV diagram, and with a larger ratio, on the contrary, it reduces the parameters of the engine efficiency. Further increasing the diameter of the displacer is not advisable in terms of technical and economic ratios. The proposed engine with external heat supply is capable of converting heat from geothermal or industrial wastewater, as well as heated water using a solar collector.

Research of transverse dynamic oscillation for the piston in labyrinth compressor

In labyrinth compressor, non-contact labyrinth sealing clearance was designed between piston and cylinder wall to process oil-free gas containing fine particles. To prevent the collision between piston and cylinder wall, this labyrinth clearance was usually set bigger than 2‰ of the piston diameter. Such a big clearance seriously increased the leakage rate and reduced the volume efficiency of the compressor. Thus, it was necessary to investigate the piston transverse oscillation, and find a way to minimize the oscillation amplitude to reduce the labyrinth clearance set. In this paper, a dynamic model was established to predict the piston transverse oscillation based on inertia mass vibration analysis and finite difference method. Experiments investigation of the piston transverse oscillation track showed high prediction accuracy of the proposed model. Then, structure parameters optimization of the compressor was carried out to reduce piston oscillation amplitude. It was found that ratio of the crank shaft radius to connecting rod length and the position of the guide bearing were two key parameters determining the oscillation amplitude. Finally, a case study showed that the oscillation amplitude could be reduced by 53% by adopting optimized parameters.

Optimization analysis of linear compressor using R290 for capacity-modulation performance improvement

Abstract The capacity-modulation performance of a linear compressor is greatly affected by the relationship between input parameters and control parameters owing to the free-piston structure. This study investigates the capacity-modulation characteristic theoretically and proposes an optimization method of the linear compressor for better performance. Suitable configurations for capacity-modulation are obtained based on the judging criteria of adjusting-range of required voltages and the relationship between supply voltages and output powers. The results show that piston diameter has a significant impact on capacity-modulation performance. The parameter combinations of initial clearance and spring stiffness under different piston diameters are divided into different zones, and zones for suitable configurations show similar shapes. A prototype using R290 is developed according to the optimization results and tested under the rated condition. The experimental results show great agreement with the analytical results, and the prototype shows excellent cooling and capacity-modulation performance with the cooling capacity ranging from 583.8 W to 1628.6 W, which demonstrates the accuracy and reliability of the optimization method. The maximum coefficient of performance is up to 4.25 under the condition of the evaporation temperature, condensation temperature, super-heating degree, and sub-cooling degree of 2.7 °C, 42.3 °C, 10.0 °C, and 4.0 °C, respectively.

Sizing Optimization of Pneumatic Actuation Systems Through Operating Point Analysis

Abstract This paper reports a study on the static and dynamic behavior of pneumatic actuation systems, resulting in a comprehensive view of the influence of the system parameters on the energy efficiency and dynamic performance. The operating point approach based on the steady-state analysis of a pneumatic actuation system is used for developing analytical expressions to describe the relationship between the piston diameter and the system performance, including displacement time, stroke end velocity, and energy efficiency. The validity of the proposed equations is demonstrated by comparison with results from a test rig. Sensitivity analysis using a nonlinear dynamic simulation model indicated that a specific operating region exists, where good energy efficiency and the maximum dynamic performance are achieved. Moreover, the results show that an oversized system becomes more inefficient in both energetic and dynamic aspects. The results obtained provide a very consistent foundation for developing a method for pneumatic system sizing.

Simulation and verification of measurement system for deep-sea pressure and its small fluctuation pressure

Combined pressure measuring system (CPMS), which is mainly used for measuring deep-sea larger pressure and its small fluctuation pressure, is studied. First, the working principle of the CPMS is introduced. Second, the mathematical model of the CPMS is established. Third, the influence of the cross-sectional area of the piston, the equivalent mass of the piston, the diving speed, the cross-sectional diameter of the compensator piston, the air content of the liquid medium, and the small fluctuation pressure on the measurement performance of the CPMS is analyzed using the simulation model. Then, the design principle of the system is summarized. Finally, the test platform is built. The results show that the dynamic pressure is not more than 0.025 bar when the pressure change speed is 0.2 bar/s, the pressure is 2.8 × 10−3 bar under 20 bar, thereby verifying the validity and accuracy of the measurement method and providing theoretical basis and reference for the design and optimization of the measurement system.

Development of a Beta-Type Moderate-Temperature-Differential Stirling Engine Based on Computational and Experimental Methods

Stirling engine is a favorable technique in the application of waste heat recovery or cogeneration system. This paper aims at developing a beta-type Stirling engine which is operated at moderate heating temperature (773–973 K). Rhombic drive mechanism is utilized to make coaxial motion of displacer and piston. Based on the proposed dimensions, a theoretical model combining thermodynamic and dynamic analysis is built to predict the performance of the Stirling engine. Thermodynamic analysis deals with variations of properties in each chamber while dynamic analysis handles the resultant shaft torque produced by the Stirling engine. Furthermore, a prototype engine is manufactured, and experimental test is carried out to validate the simulated results in this research. Under heating temperature of 973 K, charged pressure of 8 bar, rotation speed of 1944 rpm, shaft power of 68 W is obtained from the prototype Stirling engine. Power density is calculated to be 1.889 W-c.c.−1 by theoretical prediction and 1.725 W-c.c.−1 by tested result. The impact of the geometrical dimensions is investigated to survey the optimal piston diameter which is related to compression ratio and swept volume.

Development and research the electronic control system for gas engines converted on the basis of diesels

The object of research is an electronic microprocessor control system for gas internal combustion engines with spark ignition for operation on liquefied petroleum gas. The system consists of two main subsystems, the accumulative power supply common rail LPG injection subsystem and the contactless electronic ignition subsystem with a movable voltage distributor. In addition, the control system also includes a subsystem for controlling the filling of the cylinders with the charge of the working mixture, consisting of a throttle valve and an idle speed regulator with a conical damper. The control system, depending on the software version, is capable of providing group or sequential injection of liquefied petroleum gas into the inlet pipe of each cylinder in the area close to the inlet valve. Such a control system can be used when converting (re-equipping) both new diesel engines into spark-ignition gas engines, and those that are in operation. The feasibility of such a conversion is to reduce operating costs with powerful vehicles for diesel fuel, by replacing it with cheaper and environmentally friendly liquefied petroleum gas.To test the efficiency of the control system, a D-240-LPG-«B» model gas engine was developed and manufactured to operate on liquefied petroleum gas. The gas engine was converted on the basis of the D-240 transport diesel engine (atmospheric, four-stroke, liquid-cooled, 4-cylinder engine with a piston diameter of 110 mm and a stroke of 125 mm). Reducing the compression ratio of the diesel engine was achieved by modifying a semi-closed diesel combustion chamber of the TsNIDI type into an open combustion chamber in the form of an axisymmetric «truncated cone». For efficient control of three subsystems of the D-240-LPG-«B» model gas engine, an electronic microprocessor control unit of the Avenir Gaz 37 «B» model was developed and manufactured. The tests carried out on the D-240-LPG-«B» gas engine with the Avenir Gaz 37 «B» control unit showed the efficiency of using the electronic microprocessor control system.

Investigation on fuel injection quantity of low-speed diesel engine fuel system based on response surface prediction model

To analyze the fuel injection quantity of low-speed diesel engine fuel system, an AMESim model was established. Its accuracy was validated by fuel injection quantity and system pressures. Based on D-optimal design of experiment and partial least squares regression, the response surface prediction model of fuel injection quantity was obtained. The R2 and Radj2 of the prediction model are 0.995 and 0.984 respectively and the standardized residuals of the predicted values are distributed between −2 and 2. Meanwhile, the maximum relative error between the calculated and predicted fuel injection quantity is only 3.48%. The predictive capacity of the model is proved. Then the significance analysis upon the structural parameters was performed. The results show that the diameters of fuel plunger and hydraulic piston and the interactions between the diameter of fuel plunger and the diameter of high-pressure fuel tube, between the diameter of hydraulic piston and the pre-tightening force of needle spring are the key factors influencing the fuel injection quantity for their p-values are less than 0.05. Since the p-values of the diameters of high-pressure fuel tube and nozzle hole and the interaction between the two are less than 0.001, they have significant effects on fuel injection quantity.

Comparative study showing relevance of prosthesis diameter and hearing outcome in stapes surgery

<p class="abstract"><strong>Background:</strong> Otosclerosis presents as conductive hearing loss, stapedotomy is the treatment for otosclerosis, and different sizes of piston diameter are available for the procedure. Aims and objectives were to study and compare hearing improvement between the 0.4 and 0.6 mm sizes of teflon piston in stapedotomy.</p><p class="abstract"><strong>Methods:</strong> It was a prospective randomized controlled trial. Patients fulfilling inclusion criteria were subjected for small fenestra stapedotomy. Patients were divided into two groups after randomization into group A (with 0.4 mm piston diameter) and group B (with 0.6 mm piston diameter). The hearing outcome with standard audiological assessment was performed at one month and six months postoperatively. </p><p class="abstract"><strong>Results:</strong> Comparison of 1 month AB gap among the patients with 0.4 mm piston and 0.6 mm piston showed that there was no statistically significant difference among both the groups of patients (independent t test p value=0.699). Comparison of 6 month AB gap among the patients with 0.4 mm piston and 0.6 mm piston showed that there was no statistically significant difference among both the groups of patients (independent t test p value=0.54).</p><p class="abstract"><strong>Conclusions:</strong> There was no significant difference in hearing improvement among the individual methods (piston size 0.4 and 0.6) with each other both in 1 month post-operative and 6 month post-operative follow up. Hence, we conclude that there is no relevance of different diameter of teflon piston prosthesis (0.4 mm versus 0.6 mm) as far as hearing outcome is concerned.</p>

Stiffness of a Nonlinear Adiabatic Polytropic Air Spring Model: Quantitative and Conductive Investigation

The conservation of mass and energy formulas along with the Newton’s second law of motion are used to derive a simple nonlinear adiabatic air spring model. The purpose of this paper is to evaluate air spring stiffness and identify the characteristic behavior of this model. The model consists of six coupled nonlinear differential equations. The assessment of this model is based on solving these governing equations numerically using the Runge Kutta routine Matlab based platform. It has been found out that the air spring stiffness increases exponentially with the increase in the air spring piston diameter. Due to its sensitivity and its nonlinearity, the model shows signs of chaos, which have been observed in the vertical motion or in the control volume, pressure for the chosen range of parameters.

Effect of Multi-Factor Coupling on the Movement Characteristics of the Hydraulic Variable Valve Actuation

Studies show that the valve lift (VL) of the cam-driven hydraulic variable valve actuation (VVA) can be continuously adjusted in the range of 0–8.2 mm by controlling the opening of the throttling valve. In the present study, an orthogonal experiment with interaction was designed to analyze the effect of multi-factor coupling on the VL, valve-seating velocity (VSV), and pressure fluctuation in the valve piston cavity. In order to reduce the pressure fluctuation, the Taguchi method was applied to find the optimal combination of the key parameters including the diameter of the piston, the spring preload of the valve-seating buffer mechanism (VSBM), the spring preload of the valve, and the valve piston mass. The correctness of the VVA simulation model is verified through experiments. Moreover, the pressure fluctuation is analyzed through a numerical simulation. The obtained results showed that as long as the VSV is less than 0.5 m·s−1, the pressure fluctuations in hydraulic VVA can be reduced by several means, such as increasing the spring stiffness of the VSBM and valve, increasing the valve piston area and diameter size of the thin-walled hole, and reducing the valve piston mass and total hydraulic oil volume.

Application of the Taguchi method for finite element analysis of a shear-type magnetorheological fluid damper

A magnetorheological fluid damper is a device in which a magnetorheological fluid is filled in a damper. In this device, the magnetic field is controlled by an external current (voltage) so that the magnetic force of a piston inside the damper changes like an electromagnet. The damping force of the damper is controlled by changing the magnetic force of the piston. With the increasing magnetic force of the piston, the viscosity of the magnetorheological fluid in the damper increases. The primary aim of this study was to maximize the magnetic flux density and identify the following influencing factors from the relevant literature: piston and outer tube materials, piston length, piston diameter, cylinder wall thickness, damper channel clearance, gap channel length, current, and magnetorheological fluid. A magnetic circuit analysis was performed using ANSYS Maxwell, and the optimal parameter combination was identified using the Taguchi method. The analysis of variance was used to examine the influence of various factors on quality characteristics. This study helps understand the relation between structure size, material, and magnetic flux density and contributes to future generations of magnetorheological fluid damper design analysis.

Design, Construction and Evaluation of a Multi-piston Pump

The multi-piston pump, is a linear type of positive displacement pump, working on the principle of direct lift. The height to which the pump can directly lift the water is primarily controlled by factors that include the capacity of the operator, the clearance between the washers and the riser pipe and the speed of the washers. The materials for the construction of this pump can be obtained locally, even from the dump sites, hence its nickname “the pump from the dump”. It would not only serve as a means of lifting water easily, but will also improve the standard of living of the people. This pump could be an option for pumping water in relatively remote and deprived areas. This study highlights on the design, construction and evaluation of multi-piston pump. The pump went through vigorous design procedures and construction stages. The detailed working drawings of the pump were produced and constructions work carried out. Equations were established in order to know how the whole system behaves. It can be deduced from the study that pump discharge is influenced by piston diameter and the distance between the pistons. This pump can be used for small-irrigation schemes.
 Keywords: Pump; Hand-dug wells; Pipes; Discharge; Velocity.

Research on Theoretical Modeling and Parameter Sensitivity of a Single-Rod Double-Cylinder and Double-Coil Magnetorheological Damper

For the single-rod double-cylinder and double-coil magnetorheological (MR) damper studied in this paper, the damping force model of the damper is established by adopting multidisciplinary domain modeling method bond graph theory. Firstly, combined with the structure of the MR damper, the bond graph model of the MR damper was established, the damping force model of the damper was derived through the bond graph theory, and the influence factors, such as the displacement, velocity, and acceleration of the damper were considered in the model. Based on the simulation of force-displacement and force-velocity characteristics of the damping force carried out by the damper theoretical model under different currents and velocities as well as the comparison with the damper bench test results, it was found that the force-displacement and force-velocity characteristic experiment curves of the damper agreed well with the simulation results. Under different working conditions, the maximum error of damping force of the MR damper was 7.2%. The damping force model of the MR damper studied in this paper was compared with that of the damper without considering the inertia force of MR fluid, and the influence of the inertia force of MR fluid on the damping force of the MR damper was analyzed. The results show that when the frequency of the damper is large, the inertial force of MR fluid has an important influence on the damping force; therefore, considering the inertial force of MR fluid in the model can greatly improve the accuracy of the model. The influence degree of key parameters on the damping force of the MR damper was studied through the theoretical model; such key parameters ranging from large to small were the channel clearance, energizing current, piston diameter, motion velocity, channel length, zero-field viscosity of MR fluid, and nitrogen pressure. This provides a basis for the adjustment of the damping force of the MR damper.

Розроблення та дослідження системи управління газовим ДВЗ, конвертованим на базі тракторного дизеля

The article shows the feasibility and advantages of using agricultural machinery (such as powerful diesel wheeled and tracked tractors) of gas motor fuels, liquefied petroleum gas in comparison with traditional liquid motor fuels. The expediency of converting tractor diesel engines into gas engines with spark ignition is substantiated. An electronic control system for gas internal combustion engines with spark ignition is developed, consisting of two main systems and of the electronic control unit Avenir Gaz 37 level «A». The principle of operation of a gas engine control system is described, with a liquefied petroleum gas system for the intake gas through an air-gas mixer, a non-contact electronic ignition system with a movable voltage distributor, a cylinder filling system with a charge of the working mixture and Avenir Gaz 37 ECU level «A». A gas-fired internal combustion engine of the D-240- LPG-«A» model for operation in the LPG was developed and created. The gas engine was converted on the basis of the D-240 tractor diesel engine (atmospheric, four-cycle, liquid cooling, 4-cylinder engine with a piston diameter of 110 mm and a stroke of 125 mm), which is mounted on universal wheeled tractors MTZ-80 and MTZ-82. The paper presents the test results of a gas engine model D-240-LPG-«A» on the Zöllner electric load bench with an upgraded microprocessor measurement and control system. Were filmed load characteristics of the gas engine, on the basis of which the main technical characteristics of the gas D-240-LPG-«A» are determined, as well as its effective parameters. Technical characteristics showed that the rated power of the gas ICE D-240-LPG-«A» amounted to 97% of the nominal power of the D-240 diesel engine. It is proved in the article that the energy and economic parameters of the D-240-LPG-«A» gas engine obtained as a result of the tests confirmed the feasibility of converting tractor diesel engines into gas engines with spark ignition. In addition, the technical parameters obtained in the tests showed that such a conversion is an effective way to reduce operating costs by agricultural machinery by replacing more expensive diesel fuel with cheaper liquefied petroleum gas.

Effect of Piston Diameter on Internal Combustion Engine Having Six Cylinders

Earlier as in the case of petrol or diesel engine when more power is required or if there are some kind of unwanted exhaust emission then oversized pistons are used which are generally larger in diameter as compared to standard one. This paper mainly based on change in performance of the internal combustion engine having six cylinders by changing the diameter of piston. This paper compares various piston diameter performance in which we keep the friction power constant. This IC engine is work on 4-stroke diesel engine having 6 number of piston cylinder arrangement and for supply of diesel, rotary fuel injection system with KBS for cold start is use.

A Review of Diameter Measurement and a Proposal for the Improvement Thereof

In order to establish traceability of area of pressure measurement, piston–cylinder assemblies are characterized dimensionally. Piston, cylinder and master ring gauges demand diameter measurement uncertainty of about 30 nm. As focused efforts to achieve the requisite uncertainty, most of the trendy diameter measuring machines, used and available across the globe, are studied for their designs and performance. Conceptually, the uncompensated systematic error contributes significantly to the uncertainty of the measurements. In order to understand the magnitudes of the various errors, some of the key comparison reports are also studied. Based on the analysis of the review, laser-based displacement interferometer measurement systems are proposed. Theoretically, the proposed models reduce the Abbe’s error.

Performance analysis of linear compressor using R290 for commercial refrigerator

Linear compressor is a promising alternative for commercial refrigerator using R290. In this paper, a design program of linear compressor is set up. The leakage mass flow rate is modeled based on small hole leakage principle. The errors of the model are within 10%. The cooling performance of linear compressor with different piston diameter for commercial referigerator using R290 is analyzed. As the linear compressor is set to have the same swept volume, small piston diameter is beneficial to the COP improvement, but has a few decrease of cooling capacity. As the linear compressor is set to have the same cooling capacity by adjusting power frequency, COP of the linear compressor with piston diameter of 28 mm and 30 mm gets a little decrease because the power frequency deviates from the inherent frequency. The optimal piston diameter of 12 CC swept volume for the commercial refrigeration is suggested to be from 30 mm to 32 mm.