scholarly journals Analysis of Work Parameters of the Device for Hydraulic Removal of Weed Vegetation

2019 ◽  
Vol 29 (4) ◽  
pp. 614-634
Author(s):  
Andrey Yu. Izmaylov ◽  
Dmitriy O. Khort ◽  
Igor G. Smirnov ◽  
Rostislav A. Filippov ◽  
Alexey I. Kutyrev
Keyword(s):  
Penetration Depth ◽  
Movement Speed ◽  
Working Fluid ◽  
Technological Operation ◽  
Technological Parameters ◽  
Modes Of Operation ◽  
Vegetation Removal ◽  
First Case ◽  
Industrial Plantation ◽  
Hydraulic Removal

Introduction. The justification of parameters and introduction of new environmentally friendly technologies and technical means for weed control in the stalk zone is a pressing issue of major economic importance. The aim of the study is to justify the effective modes of operation trailer machine for the hydraulic removal weeds on the industrial plantation of horticultural crops. Materials and Methods. According to the analysis of existing technologies and technical means for weed vegetation removal from the stalk zone of garden plantings, a device for hydraulic removal of weed vegetation without the use of herbicides has been developed at Federal Scientific Agroengineering Center VIM. To identify the most effective modes of operation of the machine on an industrial plantation of an apple orchard, a factorial experiment was conducted. Statistical processing of the obtained experimental results was carried out using mathematical modeling. Results. The statistical analysis of the factor experiment data showed that the following operating modes of the device are the most effective for performing the technological operation of hydraulic removal weeds: the distance between the soil and the spray head is 14.5 cm, the working fluid supply pressure is 759 bar, the movement speed is 2.4 km/h. The static treatment mode for estimating the penetration depth of the jets with exposures of 10, 5, and 3 sec showed a penetration depth of 62, 34 and 12 mm, respectively. The diameters of the track were: In the first case 350 mm external and 330 mm internal (cutting width 24 mm); in the second and third cases – 340 mm for the outer and 328 mm for the inner (cutting width 16 mm). Discussion and Conclusion. As a result of the experiment, it was established that the machine is able to provide high-quality processing stalk zone when using water from the central water supply. After the unit cultivated the soil, 90% which was covered with weeds, only 20–30% of the visible green mass remains, the rest is mixed with the soil. After doube cultivation, the root system of weed vegetation remained in 10–13% of the area. The device meets the requirements of the technological operation weed vegetation removal in the stalk zone without the use of herbicides with sufficiently high technological parameters.

Quality Assessment of Machined Surfaces by an Optical Profilometer

2015 ◽  
Vol 669 ◽  
pp. 443-450
Author(s):  
Jana Gerková ◽  
Ľuboslav Straka
Keyword(s):  
Quality Assessment ◽  
Surface Quality ◽  
Production System ◽  
Head Movement ◽  
Movement Speed ◽  
Technological Parameters ◽  
Cutting Head ◽  
Optical Profilometer ◽  
Machined Surfaces

Technological parameters affecting the surface quality of cutting edges in production system with the AWJ technology include cutting head movement speed. The article examines and evaluates the quality of processed surface by the AWJ technology on selected materials as related to the change of cutting head movement speed. It was discovered that the movement speed for the AWJ technology has a significant effect on the surface quality

scholarly journals INFLUENCE OF CONSTRUCTIVE AND TECHNOLOGICAL PARAMETERS OF THE UNIT FOR STRIP TILL ON THE LUMPINESS

2020 ◽  
Author(s):  
G. Golub ◽  
◽  
A. Dvornyk
Keyword(s):  
Winter Wheat ◽  
Relative Position ◽  
Experimental Studies ◽  
Movement Speed ◽  
Technological Parameters ◽  
Depth Of Processing ◽  
Processing Depth ◽  
Economic Methods ◽  
Strip Tillage

The goal of the work. Investigate the influence of the relative position of the depth of processing with a chisel, the speed of movement of the unit and the distance between the cutting side discs on the lumpiness of the processed strip. Methods of research: analytical - quantitative determination of the quality of strip tillage; laboratory-field - for research, an experimental installation was completed with an MTZ-892 tractor and a section of the unit for strip tillage; statistical with generally accepted agronomic and economic methods. Results. Experimental studies of changes in the design and technological parameters of the unit for strip processing with the determination of lumpiness have been carried out. To study the main parameters, the depth of processing of the subsoiler (chisel) is taken from 13 to 27 cm, the distance between the cutting side discs is from 10 to 30 cm, the speed of the MTA is from 4 to 11 km/h. Unchanged parameters during the study: the distance from the axis of the front disc to the chisel is 50 cm, the distance from the chisel to the axis of the cutting side discs is 50 cm, the immersion depth of the cutting side discs is 10 cm. Experimental background is winter wheat stubble. Soil cultivation for winter wheat - deep (18 cm) disking, before that plowing to a depth of 25 cm. According to the research results, graphs of the dependence of lumpiness on the relative position of the chisel, cutting side discs and changes in the speed of the MTA were built. As the speed and distance between the side cutting discs increase, the lumpiness value decreases. Conclusions. Based on the results of the studies, the dependences of lumpiness on the relative position of the chisel and cutting side disks were obtained when the speed of the MTA was changed. It was determined that with an increase in the processing depth, the distance between the cutting side discs of 20 cm and the MTA movement speed of 7.5 km / h, a uniform increase in lumpiness is observed. The distance between the side cutting discs of 10 cm is not suitable for work.

Multi-Objective Optimization of a Combined Power and Cooling Cycle for Low-Grade and Midgrade Heat Sources

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Gokmen Demirkaya ◽  
Saeb Besarati ◽  
Ricardo Vasquez Padilla ◽  
Antonio Ramos Archibold ◽  
D. Yogi Goswami ◽  
...  
Keyword(s):  
Thermodynamic Cycle ◽  
Solution Concentration ◽  
Working Fluid ◽  
Low Grade ◽  
Basic Solution ◽  
Heat Sources ◽  
Fluid Mixture ◽  
Cooling Cycle ◽  
Multi Objective ◽  
First Case

Optimization of thermodynamic cycles is important for the efficient utilization of energy sources; indeed, it is more crucial for the cycles utilizing low-grade heat sources where the cycle efficiencies are smaller compared to high temperature power cycles. This paper presents the optimization of a combined power/cooling cycle, also known as the Goswami cycle, which combines the Rankine and absorption refrigeration cycles. The cycle uses a special binary fluid mixture as the working fluid and produces a power and refrigeration. In this regard, multi-objective genetic algorithms (GAs) are used for Pareto approach optimization of the thermodynamic cycle. The optimization study includes two cases. In the first case, the performance of the cycle is evaluated as it is used as a bottoming cycle and in the second case, as it is used as a top cycle utilizing solar energy or geothermal sources. The important thermodynamic objectives that have been considered in this work are, namely, work output, cooling capacity, effective first law, and exergy efficiencies. Optimization is carried out by varying the selected design variables, such as boiler temperature and pressure, rectifier temperature, and basic solution concentration. The boiler temperature is varied between 70–150 °C and 150–250 °C for the first and the second cases, respectively.

scholarly journals Unmanned Helicopter Type Aircraft for the Pesticides and Fertilizers Application

2020 ◽  
Vol 14 (1) ◽  
pp. 61-68
Author(s):  
L. A. Marchenko ◽  
M. V. Myzin ◽  
I. V. Kuznetsov ◽  
T. V. Mochkova ◽  
A. Yu. Spiridonov
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Agricultural Land ◽  
Unmanned Aircraft ◽  
Nitrogen Fertilizers ◽  
Working Fluid ◽  
Unmanned Aerial Systems ◽  
Unmanned Helicopter ◽  
Agricultural Field ◽  
Technological Parameters ◽  
Aerial Vehicle

Digital agricultural production is based on robotic agricultural technologies for the use of pesticides and fertilizers using unmanned aerial systems, which are based on unmanned aerial vehicles for monitoring agricultural land, the pesticides application, fertilizers and other agrochemicals. (Research purpose) To develop an unmanned helicopter based aircraft for applying pesticides and fertilizers, and to substantiate its technological parameters. (Materials and methods) The authors used methodological recommendations on the use of chemicals in the precision farming system, regulatory and technical documentation for unmanned aircraft systems. (Results and discussion) The authors determined the unmanned aerial vehicle main flight technical and technological parameters for the implementation of the applying pesticides and fertilizers process. They established the dependences of its productivity on the norms of introducing working fluids of pesticides and fertilizers, the agricultural field length, and the approach distance to the field. (Conclusions) The authors developed a helicopter-type unmanned aerial vehicle of a coaxial design with a take-off mass of 280 kilograms and a payload of 50-80 kilograms, a rotor diameter of 5.3 meters, a constructive boom width with sprayers of 5 meters, a working flight height of 1-5 meters, a working speed of 40-60 kilometers per hour, the rate of working fluid of pesticides application 10-20 liters per hectare and nitrogen fertilizers 30-120 liters per hectare. They established rational values for the application rates of pesticides – 10-20 liters per hectare, the agricultural field length – at least 0.8 kilometers, ensuring maximum productivity in flight hour when processing the agricultural field. They showed that the flight distance minimizing from the runway to the field significantly increased the productivity of applying pesticides and fertilizers.

scholarly journals Features of micro- and ultrastructure of low-fat butter and its low-fat analogues

Food systems ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 15-19
Author(s):  
E. V. Topnikova ◽  
E. N. Pirogova ◽  
Yu. V. Nikitina ◽  
T. A. Pavlova
Keyword(s):  
Penetration Depth ◽  
Milk Powder ◽  
Freeze Fracture ◽  
Milk Proteins ◽  
Average Diameter ◽  
Continuous Phase ◽  
Fat Content ◽  
Water Soluble ◽  
Low Fat ◽  
First Case

The aim of the research was to study the features of the structure of low-fat butter and butter pastes, which, in terms of composition and properties, more fully meet the requirements of a healthy diet than high-fat types of butter. The objects of research were: butter with fat content of 72.5%; butter with fat content of 55% made with the addition of skimmed milk powder; butter of the same fat content with the addition of stabilizers based on guar and xanthan gums and emulsifiers based on monoand diglycerides of fatty acids; butter pastes with fat content of 45% with similar additives used to increase the stability of the process of butter formation and improve the texture. The microstructure was studied using an MBI-6 microscope, and the ultramicrostructure was studied using a Phillips electron microscope. In the first case, the sample was prepared by crushing the sample, in the second one — by the method of ultrafast freeze-fracture and etching. Researches have shown that the use of the introduced ingredients improves the homogeneity of the structure of the studied products. Due to the ability of milk proteins and stabilizers to retain moisture, it is more evenly distributed and well retained in the fat matrix of the product, formed from crystalline and liquid fat in the form of a continuous phase, which is confirmed by a sufficient penetration depth of the fat-soluble dye. Plasma droplets in butter with fat content of 72.5% and 55% are more isolated than in butter pastes, as indicated by the greater penetration depth of the water-soluble dye. The average diameter of isolated moisture droplets in low-fat products was 3.3–5.4 μm, and the average diameter of the fat globules that form the basis of the crystalline framework was 5.4–7.4 μm, depending on the composition of the product. For butter with fat content of 72.5%, the values of these indicators were 2.8 and 4.0 μm. The results of the study indicate the presence of differences in the sizes of structural elements, but at the same time confirm the uniformity of the structure of low-fat products, allowing them to be attributed to dispersions «water-in-oil».

scholarly journals Analysis of the Throttle Speed Control Efficiency in Volumetric Hydraulic Drives

2019 ◽  
pp. 13-33
Author(s):  
K. D. Efremova ◽  
V. N. Pilgunov
Keyword(s):  
Control Method ◽  
Hydraulic Drive ◽  
Hydraulic Cylinder ◽  
Movement Speed ◽  
Working Fluid ◽  
Total Efficiency ◽  
Control Methods ◽  
Output Link ◽  
Hydraulic Cylinders ◽  
Load Characteristics

To control a movement speed of the output link of an executive hydraulic engine (hydraulic cylinder or hydraulic motor), volumetric hydraulic drives traditionally use volumetric and throttle control methods. Under volumetric control, a supply unit employs a pressure-regulated positive displacement pump, as a result of which it is impossible or difficult to separate and independently control the movement speed of the output links of the hydraulic cylinders. In case of throttle control, there is a significant dependence of the speed of the output link on the load it overcomes, a low efficiency of the hydraulic drive and hereto related active heating of the working fluid, as well as large energy losses. However, in embodiment, due to lack of an expensive variable pump, this method of control is much cheaper and can be used in a multi-channel hydraulic drive with a centralized supply unit.Depending on the throttling device localization in the hydraulic drive circuit, there are series (primary or secondary control) and parallel (working fluid bypass adjustment) throttle connection schemes. The secondary control scheme, which generates a pressure in the outlet of the executive hydraulic engine, is preferable due to the fact that it provides an increased pressure in both cavities of the executive hydraulic engine and, accordingly, a lack of combined air bubbles in the working fluid. Heat released in the throttle is discharged directly into the tank, and the pressure in the outlet reduces the danger level of the emergency situation consequences in the event of an unauthorized change in the sign of the load to be overcome. The quality of control is, mainly, assessed by the type of load characteristics, i.e. dependences of the output link speed and its developed power on the load to be overcome, as well as by the control efficiency (the total efficiency value of the regulating and executive subsystems of the hydraulic drive). The dependence of the dynamics and kinematics of the hydraulic drive on the control methods are of particular interest.The proposed paper, based on the developed mathematical models and their testing for specific sizes of hydraulic cylinders presents the numerical values of the load characteristics and dependences of the total efficiency on the load value to be overcome. Shows that the speed load characteristic steepness of an executive hydraulic cylinder and the sign of its derivative are determined by the throttle control method. The greatest power developed by the output link of the hydraulic engine is shifted to the loads that are 50 ... 70% of their maximum value.As a result of theoretical studies using numerical calculation methods, a technique has been developed for selecting a throttle control method with an assessment of its quality and efficiency. The results of the conducted studies expand the capabilities to forecast the dynamics and kinematics of the output link of the hydraulic drive at the stage of its engineering design.

Design and Operational Challenges of Switching Working Fluid for a Gen IV Nuclear Powered Closed-Cycle Gas Turbine: Case Studies of Nitrogen and Air, Helium and Argon

2020 ◽  
Author(s):  
Emmanuel O. Osigwe ◽  
Arnold Gad-Briggs ◽  
Nasiru Tukur ◽  
Pericles Pilidis
Keyword(s):  
Gas Turbine ◽  
Case Studies ◽  
Nuclear Power ◽  
Cycle Performance ◽  
Working Fluid ◽  
Closed Cycle ◽  
Working Fluids ◽  
First Case ◽  
Gen Iv

Abstract A unique benefit of using the closed-cycle gas turbine and gas turbomachines employed in the Gen-IV nuclear power plant is the flexibility it offers in terms of working fluid usage. This is so because of the self-containing nature of the closed-cycle gas turbine. To this end, the selection of the working fluid for the cycle operation is driven by several factors such as the cycle performance, system design, and component material compatibility with fluid properties, availability, and many more. This paper provides an understanding of the design and operational challenges of switching working fluids for a nuclear powered closed-cycle gas turbine. Using the plant output power of a simple closed-cycle configuration as a baseline condition, two case studies have been presented in this paper to explore the design and operational challenges of switching working fluids. In the first case study, the fluid was switched from nitrogen to air and in the second case study, helium and argon were utilised. In both cases, using thermodynamic flow relationship, the closed-cycle gas turbine turbomachinery components maps were analysed to understand the operational requirements for switching the working fluids. The paper also provided an insight into the turbomachinery component design considerations for this to be achieved. The overarching results from a thermodynamic perspective showed fluids with similar thermodynamic behaviour could be switched during idle synchronous speed.

scholarly journals THE PREDICTION OF STATIONARY MODES OF OPERATION OF GAS SUPPLY SYSTEMS BY THE METHOD OF INTEGRAL COEFFICIENTS

2019 ◽  
pp. 71-76
Author(s):  
Ye. I. Kryzhanivskyi ◽  
V. Ya. Hrudz ◽  
V. Ya. Hrudz (jun.) ◽  
R. V. Tereshchenko
Keyword(s):  
Operation Mode ◽  
Resistance Coefficient ◽  
Transmission System ◽  
Gas Pipeline ◽  
Technological Parameters ◽  
Modes Of Operation ◽  
Additional Information ◽  
Input And Output ◽  
Output Information ◽  
Main Gas Pipeline

The authors present the methods of generating the system of the integral coefficients of influence for gas transmission systems aiming at the estimation of the parameters of its work on stationary operating modes. Each change of the technological parameters of the operation mode at the input of the gas transmission system will necessarily cause the reaction of the system which will manifest itself in changing the corresponding parameters at its output. Obviously, the parameters of the input and output of the system are interconnected by a complex system of equations, the implementation of which requires certain time costs and gathering additional information about the technical and hydrogasdynamic states of the system at each moment. Under the conditions of incomplete loading of the gas transmission system, which involves frequent changes in its operation modes, the accomplishment of the task is not always possible. It is suggested to create a system of integral coefficients of influence which characterize the ratio of input and output information in different stationary modes, and formally submit it in a matrix form. The processes characterized by integral coefficients of influence implicitly contain the technological parameters of the gas pipeline (length, diameter, hydraulic resistance coefficient, heat transfer to the environment, etc.) which can not always be determined with sufficient accuracy by the deterministic methods. The suggested methodology involves the creation of simple and effective methods of predicting which allow estimating the state of the gas pipeline by the costs and pressures at the inputs and outputs of the system, that is, by the operational data that are being monitored. On the basis of the proposed methodology, it is suggested to create an operational system that will allow managing the modes of operation of the main gas pipeline in cases of frequent changes in pumping volumes. When changing the technological scheme of the gas transmission system, there is a need to adapt the integral coefficients of influence. The application of the proposed methods is illustrated by the example of the main gas pipeline Soyuz.

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 Simulation Of The Process Of Cavitation Treatment Of Liquid Feed

2021 ◽  
Vol 24 (2) ◽  
pp. 16-26
Author(s):  
Elchyn Aliiev ◽  
Roman Maliehin ◽  
Vitalii Ivliev ◽  
Olha Aliieva
Keyword(s):  
Liquid Phase ◽  
Rational Design ◽  
Film Flow ◽  
Cavitation Number ◽  
Raw Material ◽  
Movement Speed ◽  
Technological Parameters ◽  
Cavitation Phenomenon ◽  
Liquid Feed ◽  
Operation Process

The same fractional composition and uniformity of distribution of raw material components of plant origin in the mixture are the main criteria for the liquid feed quality. This is ensured by the homogenisation and dispersion of feed components using cavitation treatment. The purpose of the study is to simulate the process of cavitation treatment of liquid feed with a rotary cavitation disperser-homogeniser and substantiate its rational design and technological parameters. The task is to create such a rotary cavitation disperser-homogeniser, which allows simultaneously performing technological processes of dispersion, emulsification, and homogenisation of mixture components in a liquid medium with higher productivity, quality, and lower energy consumption. As a result of modelling the action of a rotary cavitation disperser-homogeniser in the Star CCM+ software, the distributions and dynamics of velocities of the liquid phase of the mixture and the pressure and concentration of the gaseous phase of liquid in the diffuser are established, which indicates the presence of cavitation. This confirms the operability of the developed design and technological facilities for the preparation of liquid feed and indicates the expediency of further research to substantiate its technological parameters. As a result of numerical modelling of the operation process of a rotary cavitation disperser-homogeniser, the dependences of the maximum (max) and minimum (min) movement speed of the liquid phase of the mixture in the inlet Vin and in the diffuser Vrot on the rotor speed n, inlet diameter Din and the number of resonators Nhole are determined. The qualitative criterion for evaluating the cavitation phenomenon in the developed equipment is the maximum and minimum cavitation number Xmax and Xmin, which depends on the rotation speed of the rotor n, the inlet diameter Din and the number of resonators Nhole. The value of the cavitation number Xmin=0.08 and Xmax=0.57 is achieved at n=2725 rpm, Din=0.049 m, Nhole=48, which corresponds to a film flow of liquid with a stable separation of the cavitation cavity from the rest of the continuous flow (film cavitation)

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