scholarly journals Assessment of Hydrostatic Temperature Conditions Machine Plate Supports

2019 ◽  
pp. 1-6
Author(s):  
Almokhammad A. Mokhammad ◽  
Evgeny A. Sorokin ◽  
Maksim V. Brungardt
Keyword(s):  
Support System ◽  
Metal Cutting ◽  
Experimental Studies ◽  
Hydraulic Drive ◽  
Operation Time ◽  
Operating Conditions ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Operational Conditions ◽  
Temperature Deformations

The working fluid temperature in the hydrostatic support system of the metal working machine plate is determined as a function of the drive operation time under different operating conditions. Temperature deformations of parts, units and assemblies of metal cutting machines are greatly influenced by the temperature of hydraulic drive working fluid, so the issues of optimization of working fluid temperature are given more attention. Experimental studies of the operating fluid temperature of the hydraulic support system of the faceplate and parameters affecting its changes were carried out under conditions close to operational conditions. Parts of different mass (0.5-3.8 t) were processed at different speeds of plate rotation

scholarly journals Experimental and Theoretical Analysis of a Linear Focus CPV/T System for Cogeneration Purposes

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2960 ◽  
Author(s):  
Carlo Renno
Keyword(s):  
Focal Length ◽  
Concentration Field ◽  
Operating Conditions ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Atmospheric Conditions ◽  
High Concentration ◽  
Environment Temperature ◽  
Temperature Levels ◽  
T System

The knowledge of the actual energy performances of a concentrating photovoltaic and thermal (CPV/T) system with a linear focus optics, allows to evaluate the possibility of adopting this type of system for cogeneration purposes. Hence, the main aim of this paper is the design, realization, setting and modeling of a linear focus CPV/T system in the high concentration field. An experimental linear focus CPV/T plant was created in order to determine its electrical and thermal performance under different working conditions in terms of environment temperature, sunny and cloudy conditions, focal length, etc. Moreover, a theoretical model of the linear focus CPV/T system was also studied. This model evaluates the temperatures of the working fluid that flows in the cooling circuit of the CPV/T system under several operating conditions. The temperatures of the triple junction (TJ) cells, experimentally evaluated referring to different solar radiation and atmospheric conditions, were considered as the input data for the model. The values of the fluid temperature, theoretically and experimentally determined, were thus compared with good agreement. The electrical production of the CPV/T system depends generally on the TJ cell characteristics and the concentration factor, while the thermal production is above all linked to the system configuration and the direct normal irradiance (DNI) values. Hence, in this paper the electric power obtained by the linear-focus CPV/T system was evaluated referring to the cogeneration applications, and it was verified if the TJ cell and the cooling fluid reach adequate temperature levels in this type of system, in order to match the electrical and the thermal loads of a user.

scholarly journals Comparing hydraulic and electromechanical drives by electric motor’s power

2019 ◽  
Vol 294 ◽  
pp. 01002
Author(s):  
Otto Grigorov ◽  
Galyna Anishchenko ◽  
Evhen Druzhynin ◽  
Vsevolod Strizhak ◽  
Mariana Strizhak ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Electric Motor ◽  
Asynchronous Motor ◽  
Hydraulic Drive ◽  
Operation Time ◽  
Operating Conditions ◽  
Positive Displacement ◽  
Work Cycle

The authors have made the analysis of energy consumption by positive-displacement hydraulic drive and asynchronous motor with phase rotor in the course of crane mechanisms operation at all stages of motion: acceleration, movement at nominal or intermediate speed, and deceleration. There have been determined and compared equivalent capacities per work cycle for electric and hydraulic drives of crane mechanisms depending on operating conditions group and operation time. There has been justified the decrease of rated capacity of electric motor of crane mechanisms’ hydraulic drive as compared with the case of applying asynchronous motor with phased rotor for the same mechanisms.

Applicability of Pump Models for Varying Operational Conditions

2003 ◽  
Author(s):  
Heikki O. J. Kauranne ◽  
Jyrki T. Kajaste ◽  
Asko U. Ellman ◽  
Matti T. Pietola
Keyword(s):  
Rotational Speed ◽  
Operating Conditions ◽  
Fluid Temperature ◽  
Limited Information ◽  
Operational Conditions ◽  
Axial Piston Pumps ◽  
Pump Construction ◽  
Temperature And Pressure ◽  
Axial Piston ◽  
Type Pressure

It is commonly known that the characteristics of a fluid power pump depend on pump type, pressure, rotational speed and displacement. But in addition to these, also all the other parameters or factors associated with the operating conditions may have a significant effect on the characteristics. The most important of these are the pump construction and size, operating point temperature and the characteristics of the oil, which also depend on temperature and pressure. The aim of this study is to show the effects that the varying operational conditions have on the characteristics of a axial piston pump, to compare the measured characteristics with other published characteristics of axial piston pumps and to study the capability of pump models to represent these characteristics. The results include information of the effects of fluid temperature, type of fluid and the setting value of the displacement on the pump characteristics along with the effects of pressure and rotational speed. The sensitivity of the pump to each of the parameters is discussed. The effect of limited information of pump characteristics on the reliability of simulation results is studied using the Schlo¨sser models.

scholarly journals SELF-CLEANING FILTER FOR CLOSED HYDROSYSTEMS OF AGRICULTURAL EQUIPMENT

2021 ◽  
Vol 295 (2) ◽  
pp. 130-138
Author(s):  
M. STADNIK ◽  
◽  
А. VIDMYSH ◽  
S. SHARGORODSKIY ◽  
V. RUTKEVYCH ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Pressure Pulsation ◽  
Experimental Studies ◽  
Hydraulic Drive ◽  
Operating Mode ◽  
Working Fluid ◽  
Hydraulic Systems ◽  
Agricultural Equipment ◽  
Self Cleaning ◽  
Special Stand

The issue of increasing the reliability and durability of hydraulic units of closed hydraulic systems of agricultural equipment is considered, due to better cleaning of the working fluid by filtration units. The design of a self-cleaning filter with hydraulic automatic control of backwashing of slotted filtration elements with a counterflow of the working fluid is proposed. A special stand has been developed for simulating the operation of a self-cleaning filter of closed hydraulic systems of agricultural equipment. Experimental studies on a special stand confirmed the efficiency of the proposed design and made it possible to identify its main advantages in comparison with domestic and foreign counterparts. Based on the analysis of transient processes with increased pressure pulsation of agricultural equipment of a closed hydraulic drive, the actual pressure drop at which automatic flushing is triggered was established, compared with the calculated one, in which it was impossible to take into account such real factors as friction in the sealing units, the characteristics of the springs, distortions, tightness of valve pairs, fluctuations in dimensional chains. The most optimal operating mode of auto-washing equipment with a choke diameter of 1.0 mm has been determined. The auto-washing equipment was switched on at a pressure drop of 1.5 MPa (15 atm) and in an improved mode – pressure pulsations with an amplitude of 2 MPa (20 atm) when the auto-wash was turned off decreased in time to 0.12 s. It is noted that the developed self-cleaning filter for closed hydraulic systems of agricultural equipment will improve the reliability and increase the service life of the elements of hydraulic units and the machine itself as a whole.

Sustainable management of leakage from wastewater pipelines

2005 ◽  
Vol 52 (12) ◽  
pp. 189-198 ◽  
Author(s):  
D. DeSilva ◽  
S. Burn ◽  
G. Tjandraatmadja ◽  
M. Moglia ◽  
P. Davis ◽  
...  
Keyword(s):  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Sustainable Management ◽  
Potential Effect ◽  
Operating Conditions ◽  
Pipeline System ◽  
Operational Conditions ◽  
Pipe Networks ◽  
Support Tools

Wastewater pipeline leakage is an emerging concern in Europe, especially with regards to the potential effect of leaking effluent on groundwater contamination and the effects infiltration has on the management of sewer reticulation systems. This paper describes efforts by Australia, in association with several European partners, towards the development of decision support tools to prioritize proactive rehabilitation of wastewater pipe networks to account for leakage. In the fundamental models for the decision support system, leakage is viewed as a function of pipeline system deterioration. The models rely on soil type identification across the service area to determine the aggressiveness of the pipe environment and for division of the area into zones based on pipe properties and operational conditions. By understanding the interaction between pipe materials, operating conditions, and the pipe environment in the mechanisms leading to pipe deterioration, the models allow the prediction of leakage rates in different zones across a network. The decision support system utilizes these models to predict the condition of pipes in individual zones, and to optimize the utilization of rehabilitation resources by targeting the areas with the highest leakage rates.

Performance Analysis of Photovoltaic Thermal (PVT) Panels Considering Thermal Parameters

2016 ◽  
Author(s):  
W. J. A. Jayasuriya ◽  
A. U. C. D. Athukorala ◽  
A. T. D. Perera ◽  
M. P. G. Sirimanna ◽  
R. A. Attalage
Keyword(s):  
Wind Speed ◽  
Performance Analysis ◽  
Mass Flow ◽  
Flow Analysis ◽  
Operating Conditions ◽  
Solar Irradiation ◽  
Heat Transfer Fluid ◽  
Design Parameters ◽  
Working Fluid ◽  
Fluid Temperature

Solar PVT panels are getting popular for wider spectrum of applications for concurrent heat and power generation (CHP). These panels can provide the heating demand of buildings while generating electricity which becomes ideal for building applications of urban energy systems. Energy flow analysis of such panels and performance analysis of such systems becomes essential to design PVT systems matching with the operating conditions. A number of studies have used both theoretical and experimental methods to optimize PVT. However, this task is challenging due to interrelation of CHP production based on two different phenomena where classical optimization methods cannot be applied directly. Hence basic performance analysis considering primary design parameters plays a major role. In this study, a computational model is developed to evaluate sensitivity of design, operating and climatic parameters for a hybrid PVT system and to analyze the performances of PVT for five different design configurations. Five main configurations of the PVT system are considered based on the heat transfer fluid and the arrangements of glass and tedlar layers of PVT collector. This study presents comprehensive performance analysis conducted to evaluate the sensitivity of mass flow rate and working fluid temperature for the five different design configurations of PVT panels. Results show that glass-tedlar water collector performs better when compared to other configurations. Subsequently, the sensitivity of wind speed and solar irradiation is evaluated. The behavior of thermal and electrical efficiencies is analyzed at different wind speed and solar irradiation levels for a range of mass flow rates and working fluid temperatures. Important conclusions on the performance of PVT panels are given based on this detailed analysis.

scholarly journals Determination of allowable fluid temperature during start-up operation of outlet header under the assumption of constant and temperature-dependent material properties

2013 ◽  
Vol 34 (3) ◽  
pp. 3-14
Author(s):  
Dariusz Rząsa ◽  
Piotr Duda
Keyword(s):  
Power Plants ◽  
Operation Time ◽  
Optimum Operating ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Temperature Dependent ◽  
Allowable Limit ◽  
Heating And Cooling ◽  
Start Up ◽  
Operation Cycle

Abstract Modern supercritical power plants operate at very high temperatures and pressures. Thus the construction elements are subjected to both high thermal and mechanical loads. As a result high stresses in those components are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stresses that are defined according to boiler regulations. It is important to find optimum operating parameters, that can assure safe heating and cooling processes. The optimum parameters define temperature and pressure histories that can keep the highest stresses within allowable limit and reduce operation time as much as possible. In this paper a new numerical method for determining optimum working fluid parameters is presented. In this method, properties of steel can be assumed as constant or temperature dependent. The constant value is taken usually at the average temperature of the operation cycle. For both cases optimal parameters are determined. Based on these parameters start-up operations for both cases are conducted. During entire processes stresses in the heated element are monitored. The results obtained are compared with German boiler regulations - Technische Regeln fur Dampfkessel 301.

scholarly journals IMPROVEMENT OF TECHNOLOGICAL EQUIPMENT OF THE MACHINE FOR TRIMMING TREE CROWNS IN ROADSIDE FOREST BELTS

2017 ◽  
Vol 7 (1) ◽  
pp. 205-210
Author(s):  
Попиков ◽  
Petr Popikov ◽  
Бухтояров ◽  
Leonid Bukhtoyarov
Keyword(s):  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Operating Conditions ◽  
Cutting Process ◽  
Design Parameters ◽  
Working Fluid ◽  
Hydraulic Motor ◽  
Technological Parameters ◽  
Tree Crowns ◽  
Circular Saw

When cleaning cutting, pruning of branches of roadside trees and shelter belt contour cutters are widely used, cutters is designed for total horizontal, vertical and oblique trimming crowns. These devices are hinged or removable ones and aggregated with wheeled tractors of traction class 0.6 to 1.4 kN, widespread in forestry. Improving the design of such devices is made in the following areas: cutting devices and hydraulic drives. In the proposed working body of the machine for cutting tree crowns containing base machine, crane on the handle of which a rotary hydraulic motor (rotator)is mounted, the shaft of which has movable connection with the housing of the circular saw with one-sided sharpening in the direction of the detachable part of the branch, V-shaped emphasis in the form of unilateral action hydraulic cylinder with spring-loaded rod, piston cavity which is connected in series with the drain lines of the hydraulic motor which is mounted an adjustable throttle to create pressure of the working fluid (support). In this implementation of the device when circular goes deep into the branch, which is cut, the V - shaped support with spring-loaded rod moves all the way in the branch and eliminates the clamping of the saw blade in the cut, which will improve reliability and performance. The article has developed a mathematical model of device for pruning tree crowns by circular saw with hydraulic drive on the basis of common methodology for the simulation of planar mechanisms. Differential equations of the cutting process were composed. The model of proposed design of the device for cutting tree crowns allows to study the influence of geometrical and mechanical parameters of the branches of the trees, technological parameters of cutting process on energy consumption and quality of the cut, taking into account design parameters. The model allows also to assess the performance and to examine the effectiveness of the device in different operating conditions.

scholarly journals Establishment of rational parameters of temperature of working liquid in the hydraulic drive of the excavator of the fourth dimensional group at different equipment

2021 ◽  
pp. 98
Author(s):  
Igor Pimonov ◽  
Igor Pohorilyi ◽  
Maksim Fedyuchkov
Keyword(s):  
Hydraulic System ◽  
Hydraulic Drive ◽  
Internal Flow ◽  
Technical Condition ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Hydraulic Motor ◽  
Dimensional Group ◽  
Increasing Temperature ◽  
Working Liquid

The article considers the hydraulic drive of a modern excavator on which the influence of the working fluid temperature on the power is established, depending on the technical condition of the hydraulic elements. Studies have shown that new pumps and which have operating wear, have different rational temperature of the working fluid. It is impossible to imagine modern construction machines without equipping them with a hydraulic drive. The operation of the hydraulic drive largely determines the efficiency of operation of both a single machine and the entire fleet, which consists of new and old machines . The efficiency of hydrated machines is ensured in their design, manufacture, and operation, where an important role is played by the parameters of the working fluid: the degree of its contamination and temperature (viscosity). The influence of the temperature of the working fluid on the efficiency of the hydraulic drive and the ability to control the efficiency of the hydraulic drive with the help of temperature have not been studied enough. One of the promising areas in determining the rational temperature of the working fluid is the development of new designs of heat exchangers, heaters, diagnostic devices, which will be able to assess the technical condition of individual elements and the hydraulic drive as a whole. Establishing a rational temperature of the working fluid as a necessary parameter of the hydraulic system is mandatory when using modern methods to increase the efficiency of operation, maintenance and repair of hydraulic drives. With increasing temperature of the working fluid, its viscosity decreases and the loss of pressure and power in the mains of the hydraulic drive. However, this increases the internal flow of hydraulic units, which leads to an increase in power loss. Studies have shown that new pumps and which have operational wear, have different rational temperature of the working fluid. At rational values of temperature to the hydraulic motor the worn out pumps can give almost twice more power, than at 50 ° C, recommended for new pumps. The driving power of the pump, thus, practically does not change.

scholarly journals EXPERIMENTAL RESOURCE STAND RESEARCH OF THE GOLDEN DIVISION DISTRIBUTOR

2019 ◽  
pp. 80-86
Author(s):  
Volodymyr Rutkevych
Keyword(s):  
Hydraulic Drive ◽  
Operating Conditions ◽  
Working Fluid ◽  
Stable Operation ◽  
Initial Stage ◽  
Flow Divider ◽  
Main Components ◽  
Working Bodies ◽  
Cost Characteristics

The article discusses and analyzes the operating conditions of a modern hydraulic drive. Despite the difficult operating conditions of modern agricultural machinery (difficult working conditions, frequent changes in the technological load on the working bodies, low quality of the working fluid, increased dust content and temperature fluctuations), the hydraulic drive is its main reliable element. The basis of hydraulic drives is hydraulic spool type devices, they remain the main components of a modern hydraulic drive, are able to increase energy, dynamic, cost characteristics and increase the reliability and durability of this drive. The advantages, disadvantages and directions of improvement of this drive are noted. The modern directions of development of the hydraulic drive aimed at increasing the reliability, durability and adaptability to changing the technological load on the working bodies are considered. A booth design is proposed that allows to investigate a resource study of the developed spool splitter of a forage stem feeder. As a result of the research at the initial stage, some shortcomings in the structural implementation of the developed spool of the flow divider at the time up to 2·104 cycles were revealed. After analyzing the operating conditions and making changes to the design of the stem feeder spacer spacer and retesting, the spacer spacer showed stable operation, with more than 6.6·105 load cycles.

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