Cylinder Chamber Research Articles

Research on Intelligent Control Method for Radial Spinning Pressure Balance of Three-roller Spinning

Aiming at the imbalance of radial force in the traditional spinning process, an intelligent control method for radial spinning pressure balance of three-roller spinning machine is proposed. Firstly, an indirect measurement method of spinning pressure is proposed. By measuring the pressure in the two chambers of the output oil cylinder, the pressure of the rollers is calculated. Using the electro-hydraulic servo closed-loop control principle, the intelligent control of spinning pressure can be accomplished in one cycle by changing the rolling reduction of the roller. Secondly, three intelligent control methods of radial spinning pressure balance, sequential control method, simultaneous control method and immediate control method are proposed. Three evaluation indexes of workpiece wall thickness, radial runout and ellipticity are adopted. Influence rule of three different intelligent control methods of radial spinning pressure balance on workpiece spinning dimensional accuracy are studied by the evaluation indexes. The results show that the three evaluation indexes using the radial spinning pressure balance intelligent control method are significantly improved compared with the evaluation indexes without the radial spinning pressure balance control method. The size and precision of the parts are the best by the sequential control method.

Steady and Transient Analysis of Engine Cylinder Head with Fins at 3000C and 5000C

Abstract: The combustion chamber of a motor cycle's engine cylinder is subjected to high temperatures and thermal strains, on which fins are attached to cool the cylinder, and fins are given on the cylinder to boost the heat transfer rate. Thermal investigation of an engine block with fins was performed in this paper. The heat dissipation inside the cylinder may be determined by doing thermal analysis on cylinder block fins. The premise of cylinder block cooling is to extend the fins across the cylinder block, increasing the heat transfer rate. The engine block fins' parametric model was created in 3D software Solidworks, and thermal analysis was performed on the fins with grooves and fins without grooves with and without the block to determine temperature variation in transient and steady states, that is, with and without considering over time. ANSYS software is used for thermal analysis. Analysis is also performed on other materials. In this thesis report, two models were produced in software, and amended designs of the same model were studied, as well as a comparison of two models based on geometry and material.

1194. Efficacy of shortened high-level disinfection (HLD) protocols for GI duodenoscopes with disposable tips used for endoscopic retrograde cholangiopancreatography (ERCP)

Abstract Background The most efficient combination of manual washes (MW) and high-level disinfection (HLD) cycles for the reprocessing of duodenoscopes used for ERCP is unknown. The FDA recently announced the national recommendation for transition to duodenoscopes with disposable components. Methods We studied contamination of Pentax Medical duodenoscopes with disposable tips used for ERCP. Duodenoscopes were cleaned and disinfected following removal of the disposable tip. First, one manual wash was performed with detergent and brushes that fit into the suction channel, air/water valves, cylinder, and elevator chamber. Afterward, the duodenoscope underwent HLD with an automated endoscope re-processor. Our study evaluated the success of an abbreviated cycle of one MW followed by one HLD (MW-HLD) cycle compared to a pair of MW-HLD cycles. Each duodenoscope was sampled in 4 locations after the first MW-HLD cycle and the second: 1) The elevator tab, 2) elevator channel distal opening, 3) composite duodenoscope tip, and 4) the elevator channel (Figure 1). Samples 1-3 were collected with flocked swabs. Swabs were plated on routine medias for relevant enteric pathogens. The 4th was collected by flushing 25 mL of neutralizing buffer through the elevator channel, then scrubbing the channel with a brush, followed by another 25 mL flush. The 50 mL eluent was vacuum filtered through a 0.22-micron filter and plated on TSA. Antibiotic resistance was assessed via PCR. CFU and proportion of contaminated scopes were compared between MW-HLD cycles. Results 46 duodenoscopes were sampled from September 2021 through March 2022 resulting in 92 sample events and 368 total samples. After one MW-HLD cycle, 19 of 46 (41%) duodenoscopes remained contaminated, including 5 (11%) with VRE (Table 1). After two MW-HLD cycles, 11 (24%) remained contaminated and 0 (0%) with VRE (p=0.08, 0.02, respectively). Results were similar at the sample location level (p=0.03, 0.01, respectively). Proportion of duodenoscopes contaminated with any flora and Vancomycin-resistant Enterococcus spp. Conclusion Our data demonstrate that 1 MW-HLD cycle is insufficient at decontaminating duodenoscopes with disposable tips but do support the use of two MW-HLD cycles. VRE was identified after one MW- HLD cycle, but not after two MW-HLD cycles. Further studies are needed to determine the optimal combination of MWs and HLDs while minimizing HLD staff time. Disclosures All Authors: No reported disclosures.

CFD Analysis of an IC Engine with and Without Groove

Abstract: The combustion chamber of engine cylinder of motor cycle is subjected to a high temperature and thermal stresses, on which fins are, mounted in order to cool the cylinder, fins are provided on the cylinder to increase the heat transfer rate. In this report thermal analysis of engine block with fins were analysed. By doing thermal analysis on cylinder block fins, it is helpful to know the heat dissipation inside the cylinder. The principle behind the cooling of the cylinder block is to extend the fins over the cylinder block by which the heat transfer rate will be increased. The parametric model of engine block fins has been developed in 3D software Solidworks and thermal analysis is done on the fins with groove and fins without groove with and the block to determine temperature variation in transient state and in steady state that is, with and without consider over time. The Thermal analysis is done by using ANSYS software. Analysis is conducted with varying material also. In this thesis report two model were created in software and modified design of the same model were analyzed, and comparison of two models according to geometry and material wise analysed

Extended State Observer-Based Fuzzy Adaptive Backstepping Force Control of a Deep-Sea Hydraulic Manipulator with Long Transmission Pipelines

The force tracking control of deep-sea hydraulic manipulator systems with long transmission pipelines is disposed via fuzzy adaptive backstepping control based on an extended state observer in this paper. The pipeline model is established and then used to estimate the pressures in cylinder chambers, which are used to obtain the output force. In this process, the velocity of the piston, which is unmeasured, is needed, and an extended state observer is constructed to estimate the unmeasurable velocity signal. To cope with parameter uncertainties caused by changes in working depth, an adaptive algorithm is combined with the backstepping controller. Fuzzy logic is employed to design self-tuners that can automatically adjust the control parameters to guarantee force control performance from shallow seas to deep seas. The experimental results illustrate the success of the proposed control method. Comparative experimental results demonstrate that the extended state observer-based fuzzy adaptive backstepping controller has a relatively better tracking performance in different working conditions.

Influence of long-term thermal cycling in a corrosive environment on the change in properties and microstructure of SCh20 cast iron

The article considers the study of a metal sample of the wall of the working chamber of the compressor cylinder of the model 5G-100-7 made of SCh20 cast iron, which has been in operation since 1992 and is intended for pyrogas compression at a temperature of 110 °C, decommissioned due to the end of its service life. Mechanical tests were carried out as a result of which the mechanical characteristics of the metal were determined, such as tensile strength and Brinell hardness. The chemical composition of the metal was determined and an excess of sulfur content was established, which is explained by metal contamination due to the presence of sulfur compounds in the compressible medium. Pollution of the compressible medium is caused by the imperfection of the technology for cleaning pyrolysis gas from various impurities. The microstructure of the center of the wall and the edge of the sample, which are in direct contact with the compressible medium, has been studied. It has been established that the microstructure of the sample center is typical for gray cast iron. Along the edges of the wall, rounded corrosion pits and corrosion pits are observed. As a result of the analysis of the microstructure of the surface of the wall of the working chamber, it was found that there is a layer on the surface with dissolved graphite inclusions and the formation of pearlite grains with cementite along the boundaries. Under the surface layer, ferrite grains were found, as a result of the decomposition of perlite, and the transition of carbon to graphite with a morphology different from the base metal and cementite along the periphery of graphite inclusions and ferrite grains.

Real-Time Leak Detection in High Frequency Hydraulic Cylinder Based on Intelligent Control

Most of the existing hydraulic cylinder internal leakage detection methods are laboratory testing methods, mainly the pressure-holding method, measurement of hydraulic cylinder settlement method, and measuring cup measurement method. The internal leakage of the hydraulic cylinder affects the damping characteristics of the control system. Therefore, real-time internal leakage detection plays an important role in the control characteristics. This paper first proposes a wavelet analysis-based extraction of hydraulic cylinder internal leakage fault eigenvalues for analysis, that is, data processing. A convolutional neural network-based detection method is also proposed, in which the pressure signal of a chamber of a hydraulic cylinder is first obtained through simulation under four operating conditions: no leakage, small leakage, medium leakage, and large leakage. Compared to traditional modelling methods, the method overcomes the difficulties in modelling nonlinear hydraulic systems, requires only pressure signal acquisition, is simple and reliable, and is compared with traditional BP neural networks to demonstrate its superiority.

A computational analysis of the aerodynamic and aeromechanical behavior of a thermo-well for steam temperature measurement in a steam turbine

ABSTRACT The goal of the paper is twofold: firstly, it presents computational fluid dynamics analysis for finding maximum unsteady flow forces (and their frequencies) acting on a thermo-well for measuring steam temperature in a steam turbine control stage and secondly, it presents computational solid dynamics analysis of possibility of entry into resonance of the thermo-well structure. There have been analyzed two cases of flow with changing temperature, pressure, and mass flow rate in the control stage chamber of a turbine high-pressure cylinder. The problem is also described in the ASME standard PTC19.3 TW-2010 providing detailed guidelines for thermo-well calculations. The problem under consideration is only a part of whole technical analysis and obeys a primary hypothesis that a reason of the thermo-well damage was a resonance phenomenon.

Motion characteristics and energy efficiency of potential energy recycling system of telescopic handler

Telescopic handler is combined of truck crane and forklift. Equipped with different accessories, the telescopic handler can achieve fork loading, lifting and other operations. Large amount of energy is needed to maintain lifting and lowering in large range with high frequency of the working device of telescopic handler. There is no energy recycling device for the working device that leads to the large dissipating of gravitational potential energy. In order to recycle the wasted energy, a three-chamber hydraulic cylinder boom system (TCCBS) is proposed. In this paper, the recycling principle is described. Then the energy consumption characteristics are analyzed. Further, the mode of TCCBS of telescopic handler is established and analyzed. Compared with the double chamber cylinder boom system (DCCBS), the single-action time of the boom is reduced 4.15 s. The velocity shock decrease from 0.12 m/s to 0.02 m/s at the beginning of the boom lowering process. The peak pressure decreased from 24 MPa to 21 MPa and the average pressure decreased from 17 MPa to 13 MPa during boom lifting process. The potential energy recycling of the working device is 139 kJ, which accounts for about 47.1 % of total potential energy. The cumulative output energy of TCCBS is 311 kJ, which is 92 kJ less than the DCCBS. The comprehensive energy saving efficiency is 22.3 %. The results show that the TCCBS can realize the potential energy recycling.

Design & fabrication of closed loop hydraulic press to control pressure & flow

The present paper describes the design and fabrication development of a 250kN closed-loop hydraulic actuated press to control Force, velocity and position during stamping operations as well as mechanical tests. The press has one hydraulic servomechanism: a hydraulic cylinder, driven by a servo-solenoid P/Q valve, to support the operation; The press is equipped with a pressure sensor installed in the cylinder chamber for indirectly measuring the pressing force. On the press it is also possible to measure the position of the upper plate by using a micro-pulse linear transducer, which creates a precondition for the realization of a hybrid force /position /velocity-control algorithm. The control algorithms and monitoring process are implemented on a real-time hardware board. They are programmed in the LABVIEW software. Based on the experimental results, it can be concluded that electrically actuated control components supported by the appropriate computer programs make it possible to improve the characteristics of the hydraulic systems required in modern industrial plants. The software setup allows the implementation of a hybrid controller (force + position + velocity) for the hydraulic cylinder in such a way that it will be easy to switch between force, position and velocity control.

Modeling and experimental evaluation of vibration reduction of hydraulic-driven joint with a MRF damper

In order to reduce the impact force of the legged hydraulic-robot when it is driving on the ground, a new method based on magnetorheological technology is proposed for damping control of hydraulic mechanical legs in this paper. Firstly, the structure of hydraulic-driven leg with magnetorheological fluid (MRF) damper is designed, and the magnetic field simulation analysis of MRF damper is carried out to verify the rationality of magnetic circuit. Then the effects of different damping ratios on the dynamic performance of valve-controlled cylinder system are analyzed by theoretical modeling. Further, the co-simulation modeling of MRF damper and valve-controlled cylinder is established based on AMESIM to analyze the vibration reduction effect under impact force. Finally, the experiments of the hydraulic system designed in this paper are carried out under step load and triangular-wave load to obtain the system output displacement and pressure under two kinds of loads. Compared with the results without MRF damper, it is found that the new method can reduce the increase of pressure impact by 82% and almost eliminate the pressure fluctuation in the high pressure chamber of hydraulic cylinder.

Research on a novel electro-hydraulic brake system and pedal feel control strategy

The existing electro-hydraulic brake system does not consider the adverse effect of the failure of the brake pedal feel simulator on the function of the braking system and the driving safety of the vehicle. To solve the above problems, a novel electro-hydraulic brake system is proposed. Firstly, the structural scheme and the working modes of the system are analyzed, and the electro-hydraulic brake system model is established, and a control strategy for the controlling of the wheel cylinder pressure is put forward. Then, the pedal feel control strategy is studied, which can simulate arbitrary pedal characteristics by controlling the output torque of the motor. Moreover, for the failure of the pedal travel sensor, a pedal displacement estimation method is proposed based on the pressure sensor information of the front chamber of the master cylinder. And for the failure of the pedal feel simulation motor, the pressure of the front chamber of the master cylinder is controlled by adjusting the opening of the pedal feel simulation valve to realize the simulation of the pedal feel. The simulation results based on CarSim/AMESim/Simulink show that the proposed electro-hydraulic brake system has fast pressure response speed and quick pressure tracking accuracy. The pedal characteristics are essentially unchanged before and after the failure of the pedal feel simulation motor or the pedal travel sensor.

Prediction and verification for the models of temperature rising by medium bubbles in hydraulic system

In order to obtain the influence of the medium bubble contents on temperature rising characteristics of a hydraulic system, the working hydraulic system of a wheel loader was taken as the research object. By carrying out the comparison experiments of the hydraulic system with and without de-aeration devices on a 5-ton wheel loader, the air bubble contents and concerning temperatures were obtained. To identify the factors which have impact on temperature rising of the hydraulic system, the head chamber of boom cylinder is taken to analyze, and the temperature rising expression in a volume were deduced. By the utilization of the thermal hydraulic library, combining with mechanism and control libraries on AMESim simulation platform, the integrated simulation model of the whole system was established and verified, meanwhile, the simulation was carried out from aspects in different air contents and initial chamber temperatures. From the simulation, the prediction models of the air contents to temperature rising, and the pressures to temperature rising were predicted. Finally, the correctness of the prediction models are verified by experiment data and showing good results, which can be used to enrich and improve the calculation and evaluation methods of heat generation to any other hydraulic systems.

A Novel Electro-Hydraulic Compound Driving System With Potential Energy Regeneration Capability for Lifting Device

In order to realize the high energy efficiency and high performance motion control of the lifting device of construction machinery, this paper proposes an electro-hydraulic compound driving system that can regenerate the potential energy. In this new system, the high-power density combination of hydraulic cylinder with accumulator is used to balance the self-weight of the lifting device and recycle the gravitational potential energy directly. The green electro-mechanical actuator with high energy efficiency and control performance is used to control the motion of the lifting device. In addition, control valves are added to dynamically adjust the pressure of the two chambers of the hydraulic cylinder and increase the stiffness of the hydraulic system, which can restrain the impact of acceleration and deceleration of large inertia lifting device and rapid charging and discharging of accumulator on electro-mechanical actuator. Finally, a typical construction machinery excavator is structurally modified to build a test platform. The test results show that, under the same working conditions, the proposed electro-hydraulic compound driving system can further reduce energy consumption by 31% and reduce peak power by 15% than that of the high energy efficiency three-chamber hydraulic cylinder driving system with potential energy regeneration. The boom runs smoothly, and the velocity overshoot and fluctuation time are significantly reduced, realizing high performance driving of the lifting device with low energy consumption. The research results also have broad application prospects in missile erection devices, cranes, presses, and other equipment.

Cold plasma aseptic packaging

Cold plasma aseptic packaging

Ensuring the required law implementation accuracy of the transmission clutches control by regulating the working fluid volume in the hydraulic cylinder compensation chamber

Introduction (problem statement and relevance). Testing the vehicle automatic transmission and shifting gears without interrupting the power flow undesirable dynamic phenomena were revealed. The occurrence of “parasitic” centrifugal pressure in the clutch boosters was observed which resulted in self-activation of the control element, clamping the discs friction linings, which made the hydraulic cylinder emptying and piston removing from the package disks complicated. As a consequence of it there occurred a comfort decrease in the vehicle, and in some cases, the destruction of friction clutches. It was found that the reason for this occurrence was the filling degree instability of the compensation and piston chambers of the hydraulic cylinder clutch, which was not taken into account by the existing calculation and design methods under various initial conditions.The purpose of the study was to improve the implementation accuracy of the required control law of the transmission clutches by purposeful regulating the working fluid volume in the compensation chamber of the hydraulic cylinder clutch.Methodology and research methods. A road test technique was proposed for identifying and reproducing the conditions of the dynamic phenomenon manifestation. The developed mathematical model of the piston stroke made it possible to assess the dependence of the implementation quality of the required clutch control law when individual gears were engaged on the following parameters: the filling degree of the compensation chamber; features of solenoid valves operation; the stiffness of the return spring; the number of clutch friction pairs.Scientific novelty and results. On the experimental research basis of the worked out design and the use of scientifically grounded technical solutions the dynamic effect manifestation of the unbalanced “parasitic” centrifugal pressure rise was excluded.Practical significance. The developed and implemented technical solutions for stabilizing the pressure in the compensation chamber made it possible to ensure the required quality of gear shifting when limiting the dynamic and thermal loading of the friction discs, which made it possible to ensure the required level of dynamic characteristics and comfort ability of the product when shifting gears.

Improving the tests of catalytic converters accounting for the relationship between the composition of the working mixture entering the engine combustion chamber and CO and CH in exhaust gases

The article presents results of the study aimed to establish the relationship between the working mixture entering the engine combustion chamber and CO and CH in the exhaust gases. On the basis of the theory of fuel combustion in the engine chamber and the systematic approach, and using the mathematical methods, the fuel combustion in the combustion chamber is analyzed at low ambient temperatures to decrease emissions of carbon monoxide and hydrocarbons. The criterion for optimizing the tests of catalytic converters is substantiated for low temperatures - temperatures of the heat flow of the mixture at the exit from the combustion chambers of the engine cylinder. The limitation is the warm-up time of the catalytic converter when testing it on vehicles operating at low temperatures and the standards for the content of CO and CH in the exhaust gases of a passenger car engine. The application of the methods and the mathematical model can be the basis for supplementing UNECE Regulation No. 83-06 and improving the VI type test method for vehicles operating at low ambient temperatures.

Optimization Design of an Efficient Evacuator for Gun Barrels

Abstract Evacuators are key components of gun barrels, and their main function is to drain the gunpowder gas remaining in the gun bore from the muzzle by ejection. To design an efficient evacuator for the gun barrels, an optimization model with the mathematical expressions describing the working process of the evacuator was established. The four structural parameters that affect the efficiency of the evacuator, including the volume of the gas storage cylinder chamber, the distance of the nozzle from the muzzle end face, the cross-sectional area of the nozzles and the cross-sectional area of the valves, were optimized. The effective working time and reliability indicator of the optimized evacuator were improved. This work describes a framework for improving the design of highly efficient evacuators on gun barrels.

Anterior Chamber Characteristics, Endothelial Parameters, and Corneal Densitometry After Descemet Stripping Automated Endothelial Keratoplasty in Patients With Fuchs Dystrophy.

PurposeTo compare anterior segment parameters in patients with Fuchs endothelial dystrophy (FED) who underwent Descemet stripping automated endothelial keratoplasty (DSAEK) in one eye and no corneal surgery in the fellow eye.MethodsThis prospective study was conducted on 28 eyes of 14 patients with FED who underwent DSAEK in one eye at least one year prior (DSAEK group) and no corneal surgery in the fellow eye (control group). Each eye was analyzed with the anterior segment optical coherence tomography, specular microscopy, and Scheimpflug imaging systems. Data were compared between the two groups.ResultsThe mean age of the patients was 76.9 7.0 years. There were no statistically significant differences in the mean central corneal thickness (CCT), central anterior chamber depth, anterior chamber angle parameters, cylinder and keratometry values between two groups (all P-values 0.05). The paracentral corneal thickness, corneal volume, endothelial cell density, and hexagonal cell ratio measurements were statistically significantly higher in the DSAEK group than the control (all P-values < 0.05), and anterior chamber volume in the DSAEK group was significantly less than the control (P = 0.046). While posterior and total corneal densitometry values in the DSAEK group were statistically significantly lower than the control (P < 0.001 and P = 0.011, respectively), there were no statistically significant differences in the anterior or middle corneal densities (P = 0.108 and P = 0.134, respectively).ConclusionWe found that total corneal densitometry value decreased in DSAEK group. Although DSAEK surgery did not affect the anterior chamber angle parameters, it reduced the anterior chamber volume and increased the corneal volume and paracentral corneal thickness due to the addition of the DSAEK graft.

Investigation of flow behaviour and heat rejection for an air-cooled small multi-stage swash-plate compressor

Modelling the working process of a multi-stage reciprocating compressor is essential for improved performance and reliability. However, the squeeze-like thermal flows in the cylinder and valve plate-seat chamber, and their interactions with the inter-stage and exterior cooling flows, are so complex that detailed treatments of interactions with the surrounding environment have yet to be reported. To facilitate real-environment modelling, a numerical method is proposed within the framework of a multi-physics computational fluid dynamics package by incorporating a squeeze-like dynamic mesh and the fluid-structure interaction. With the developed approach, a three-stage four-cylinder compressor is simulated, where the valve dynamics, cylinder head heat rejection mechanism, and interior and exterior thermal-flow behaviour are exhibited. The results showed that the maximum impact velocity of the Stage 1 discharge valve is 4.8 times larger than that of the suction valve, which means that the Stage 1 discharge valve is more prone to fatigue damage. The suction air temperature is superheated owing to the heating of the cylinder head, which reduces the compressor volumetric efficiency and increases the compressor work. The predicted outer surface temperature of the cylinder head is comparable to the experimentally measured value, with a deviation of less than 6.9%, thus verifying the proposed method.