scholarly journals Development and Approbation of Methodology Aimed to Define the Reasons for Turbine Unit Capacity Limitation Based on the Specified Mathematical Model of its Condenser

2021 ◽  
pp. 79-87
Author(s):  
Aleksandr Shempelev ◽  
Keyword(s):  
Mathematical Model ◽  
Turbine Unit ◽  
Operating Mode ◽  
Vacuum System ◽  
Data Sampling ◽  
Capacity Limitations ◽  
Unit Capacity ◽  
Abnormal Operation ◽  
Operational Data ◽  
Limiting Pressure

The purpose of this work is to develop and test the methodology of elucidation of the reasons for turbine unit capacity limitations based on a mathematical model of its condenser. This pur-pose is achieved by using a mathematical model of the condenser as part of the developed methodology, taking into account the separate effects of contamination of the heat exchange surfaces, air suction into the vacuum system and the operating mode of the main ejector. Based on operational data sampling, the value of the limiting pressure in the condenser, excess of which leads to limitation of turbine unit capacity, was determined. It was established that the cause of power limitation is the abnormal operation of the main ejector due to inadmissible high temperature in the intermediate cooler of its first stage. For regimes that were not pressure-limited, using a mathematical model, the degree of tubes contamination, its influence on the condenser pressure and the power generated by the turbine unit, and the influence of actual air suctions on the condenser pressure were determined. The most important result of the study is to determine the possibility and feasibility of using the developed and tested methodology for solv-ing similar problems for any type of turbine unit equipped with a condenser. The significance of the work lies in the fact that the proposed approach expands the possibilities of using mathemat-ical models of this class in terms of solving such problems.

Analysis and Simulation of One Worker with Multi-Machine Mode

2014 ◽  
Vol 889-890 ◽  
pp. 1227-1230
Author(s):  
Jin Fei Liu ◽  
Ming Chen ◽  
Xiang Long Qi
Keyword(s):  
Mathematical Model ◽  
Process Simulation ◽  
Operating Mode ◽  
Analysis Process ◽  
Machine Assignment ◽  
The Difference ◽  
Plant Simulation ◽  
Machine Work

One operator with multi-machine operating mode is an important part of the analysis of operator-machine work, because it takes it into consideration that the utilization of both machines and operators. It is necessary to study its classification, application and analysis process, besides, a mathematical model is constructed to analyze the differences in efficiency for operators and machines, which are caused by the difference of machine assignment amount. Finally, The process simulation and verification is based on the platform of Plant simulation.

Modeling and Energetic Analysis of Soybean Meal Drying in the Indirect Rotary Dryer

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
Gianini R. Luz ◽  
Paulo R. Paraíso ◽  
Luiz M. M. Jorge ◽  
Cid M. G. Andrade
Keyword(s):  
Mathematical Model ◽  
Soybean Meal ◽  
Initial Temperature ◽  
Empirical Equations ◽  
Operational Conditions ◽  
High Consumption ◽  
Rotary Dryer ◽  
Energetic Analysis ◽  
Energetic Performance ◽  
Operational Data

The process of soybean meal industrial drying requires a high consumption of energy, and it is usually performed in an indirect rotary dryer. A study aiming for the reduction of this energy consumption is vital for the competitiveness of this product. Thus, the purpose of this work was to develop a mathematical model of soybean meal drying, in permanent regime, in order to assess the optimal operational conditions of the dryer and its energetic performance. The developed model is based on balances of mass and energy, and using constitutive and empirical equations. The model validation was carried out through operational data. From this, the influences of the initial temperature, initial moisture, and relative humidity of air, as well as the dryer energetic performance, were investigated.

scholarly journals Modeling of monitoring processes with uneven and fuzzy observation intervals

2021 ◽  
Vol 4 (135) ◽  
pp. 135-148
Author(s):  
Vladislav Skalozub ◽  
Oleg Murashov
Keyword(s):  
Mathematical Model ◽  
Time Series ◽  
Fuzzy Time Series ◽  
Clinical Monitoring ◽  
Fuzzy Data ◽  
Data Sampling ◽  
Patients With Diabetes ◽  
Sampling Intervals ◽  
Weight Method ◽  
Modeling Algorithm

The paper presents the results of applying a separable mathematical model for analyzing fuzzy time series with uneven and fuzzy data sampling intervals. The study of the efficiency of an advanced quantile modeling algorithm is presented. The implementation of models of measurement sequences with fuzzy steps is conducting by applying the approach based on α-levels. The center of weight method was used for scalarization the fuzzy result. A separable model was used for modeling the processes of clinical monitoring of patients with diabetes.

scholarly journals MATHEMATICAL MODEL OF INTERACTION OF MILLING KNIVES WITH SOIL

2018 ◽  
Vol 12 (4) ◽  
pp. 67-71
Author(s):  
Александр Акимов ◽  
Aleksandr Akimov ◽  
Юрий Константинов ◽  
Yuriy Konstantinov ◽  
Борис Туровский ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Translational Motion ◽  
Operating Mode ◽  
Geometric Parameters ◽  
Relative Depth ◽  
Power Characteristics ◽  
Proposed Model ◽  
Curved Blade ◽  
Kinematic Coefficient ◽  
Force Characteristics

As working units of tillage mills, both curved (L-shaped) blade knives and straight blade knives are used. The soil reactions to these working units depend on soil properties, geometric parameters of the working parts, parameters determining the modes of their operation and the angle of rotation of the working units. When constructing a mathematical model for the interaction of working parts with soil, all these factors must be taken into account, while striving to simplify the proposed model. Accounting for the dependence of force characteristics of the working units on the angle of their rotation is not an easy task, and in most cases it is solved with the help of specially set experiments. A mathematical model is proposed for the interaction of a direct lamellar milling knife with soil, which makes it possible to determine the components of the resulting soil reactions to such a knife, the total moment of these reactions, and the power consumed for cutting the soil, depending on the knife rotation angle. This model takes into account the geometry of the working unit through the radii of the hub and cutters, the angle of installation of the milling knife and its length. The operating mode of the knife is set by the kinematic coefficient, equal to the ratio of the circumferential velocity of the knife end to the speed of the translational motion of a mill, and the maximum relative depth of the milling knife in the soil. The constructed model makes it possible to determine the dependence of the maximum values of the considered power characteristics of the knife on the indicated geometric parameters and the parameters of the knife operating mode, which makes it possible to simplify experiments to determine the power characteristics of the cutter and significantly reduce its volume. This model can be used to select the optimal knife parameters. In addition, the proposed model can be used to calculate the power characteristics of the rack of a curved blade knife, which consumes a significant amount of energy during milling.

scholarly journals Simulation of contact interaction of piezoelectric engine elements

2019 ◽  
Vol 3 (4) ◽  
pp. 222-229
Author(s):  
A. V. Azin ◽  
S. A. Kuznetsov ◽  
S. A. Ponomarev ◽  
S. V. Ponomarev ◽  
S. V. Rikkonen
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Operation Mode ◽  
Experimental Studies ◽  
Operating Mode ◽  
Element Model ◽  
Piezo Element ◽  
Element Activity ◽  
Piezo Electric

In the article the results of a new type of piezo-electric step-engine research are presented. The original construct of piezo-electric step-engine is contained in special engineering lever called grab device that can organize back and forward rod’s motion with only one piezo element activity. To choose the effective process of piezo-electric step-engine work the mathematical model was created. This mathematical model describes inner piezo-electric step-engine process with features of contact and electroelastic deformation. Using the ANSYS application package, а finite element model of the piezo-electric step-engine has been developed. This finite element model allows estimate the stress-strain state of structural elements of the piezo-electric step-engine and determine the effective step-by-step operation mode of the piezo-electric step-engine. Using the finite element model, the influence of the piezo-electric step-engine operating mode parameters on the amount of displacement of the rod is studied. According to results of experimental studies, the proposed numerical model allows to simulate the dynamic process of step-operation of a piezo-electric step-engine with an error of no more than 6 %. This finite element model include the external load on piezo-electric step-engine and can be used to design piezo-electric step-engine of various fields of application.

scholarly journals Wear issues of pumping units

2021 ◽  
Vol 264 ◽  
pp. 04081
Author(s):  
Oybek Ishnazarov ◽  
Abdusaid Isakov ◽  
Utkir Islomov ◽  
Umirzoq Xoliyorov ◽  
Dilshod Ochilov
Keyword(s):  
Mathematical Model ◽  
Wear Resistance ◽  
Service Life ◽  
Rotation Speed ◽  
Operating Mode ◽  
Factors Influencing ◽  
Pump Shaft ◽  
Pumping Unit ◽  
Pumping Units ◽  
The Mathematical Model

The article presents the possibility of increasing the service life of pumping units. Particular attention is paid to the regulation of the speed of rotation of the pumping unit. There are some assumptions in the mathematical model that do not affect the final result. The factors influencing the operating mode are given. It is indicated that the speed of rotation of the pump shaft significantly affects the wear resistance of the pump blades. Thus, the regulation of the pump rotation speed will rationally increase its service life.

scholarly journals A novel continuous berth scheduling model at multiple marine container terminals with tidal considerations

2017 ◽  
Vol 2 (2) ◽  
pp. 142-157 ◽  
Author(s):  
Ali Dadashi ◽  
Maxim A. Dulebenets ◽  
Mihalis M. Golias ◽  
Abdolreza Sheikholeslami
Keyword(s):  
Mathematical Model ◽  
Time Of Day ◽  
Container Terminals ◽  
Channel Depth ◽  
Content Type ◽  
Access Channel ◽  
Marine Container Terminals ◽  
Bandar Abbas ◽  
Berth Scheduling ◽  
Operational Data

Purpose The paper aims to propose a new mathematical model for allocation and scheduling of vessels at multiple marine container terminals of the same port, considering the access channel depth variations by time of day. Design/methodology/approach This paper proposes a new mathematical model for allocation and scheduling of vessels at multiple marine container terminals of the same port, considering the access channel depth variations by time of day. The access channel serves as a gate for vessels entering or leaving the port. During low-depth tidal periods the vessels with deep drafts have to wait until the depth of the access channel reaches the required depth. Findings A number of numerical experiments are performed using the operational data collected from Port of Bandar Abbas (Iran). Results demonstrate that the suggested methodology is able to improve the existing port operations and significantly decrease delayed vessel departures. Originality/value The contribution of this study to the state of the art is a novel mathematical model for allocation and scheduling of vessels at multiple terminals of the same port, taking into consideration channel depth variations by time of day. To the best of the authors’ knowledge, this is the first continuous berth scheduling linear model that addresses the tidal effects on berth scheduling (both in terms of vessel arrival and departure at/from the berth) at multiple marine container terminals.

scholarly journals Analysis of modern modeling methods in problems of stabilization of motions of mechatronic systems with differential constraints

2018 ◽  
Vol 7 (2.23) ◽  
pp. 9
Author(s):  
Krasinskiy A.Ya ◽  
Krasinskaya E.M.
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Operating Mode ◽  
Mechatronic Systems ◽  
Natural Behavior ◽  
Holonomic Constraints ◽  
Operating Modes ◽  
Modeling Methods ◽  
Nonlinear Mathematical Models ◽  
Steady Motions

The most important problem of controlling mechatronic systems is the development of methods for the fullest possible application of the properties of our own (without the application of controls) motions of the object for the optimal use of all available resources. The basis of this can be a non-linear mathematical model of the object, which allows to determine the degree of minimally necessary interference in the natural behavior of an object with the purpose of stable implementation of a given operating mode. The operating modes of the vast majority of modern mechatronic systems are realized due to the steady motions (equilibrium positions and stationary motions) of their mechanical components, and often these motions are constrained by connections of various kinds. The paper gives an analysis of methods for obtaining nonlinear mathematical models in stabilization problems of mechanical systems with differential holonomic and non-holonomic constraints. 

scholarly journals Development of a Distributed Mathematical Model and Control System for Reducing Pollution Risk in Mineral Water Aquifer Systems

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 151
Author(s):  
Alexander V. Martirosyan ◽  
Yury V. Ilyushin ◽  
Olga V. Afanaseva
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Mineral Water ◽  
Structural Integrity ◽  
Mutual Influence ◽  
Operating Mode ◽  
Mineral Waters ◽  
Object A ◽  
Input Action ◽  
Aquifer Systems

The article is devoted to the problem of the growing need of the mineral water fields’ exploitation process automation. The implementation of control systems and mathematical modeling methods can significantly reduce the fields’ structural integrity violation and pollution of aquifers risks. This research is especially relevant for the fields with difficult conditions of mineral waters occurrence, since the insufficient accuracy of determining the fields’ operating mode parameters can lead to a severe incident. The article describes a distributed mathematical model developed from the geo-filtration equation. Based on this model, a new method for assessing the mutual influence of the fields, the production of which is carried out from one aquifer, is presented. For a more detailed study of the operating mode parameters influence on the object a physical model of the reservoir was developed. The using of Arduino sensors and the developed software allows us to construct a 3D graph of the input action and its response at the different points of the object as temperature distribution. The simulation results make it possible to use the proposed model for the automatic control system synthesis.

Study of operating conditions and consumption fuel for a gas turbine plant.

2020 ◽  
Vol 23 (2) ◽  
pp. 65-69
Author(s):  
E. LYUBIMENKO ◽  
◽  
A.A SHTEPA ◽  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Turbine Unit ◽  
Constant Pressure ◽  
Operating Mode ◽  
Gas Turbine Unit ◽  
Optimal Operating ◽  
Turbine Plant ◽  
Gas Consumption ◽  
Gas Turbine Plant

Carrying out research work to determine the working conditions and determine the fuel consumption in a gas turbine installation. The descriptions of a gas turbine unit operating on gaseous fuel are presented: in normal and standby operating modes. The optimal operating mode of the gas turbine plant is combined: the production of heat and electricity. A study of the operating mode of a gas turbine unit at a constant pressure of 0.1 MPa and a temperature when air enters the compressor of a gas turbine unit with fuel combustion has been carried out. The features of the use of an energy carrier in a gas turbine unit during the year are highlighted and analyzed. The structure and current consumption of natural gas in a gas turbine unit for accounting for the consumption of energy carriers is described. As a result of the study, a substantiation of the concept of calculating the predictive function for accounting for the costs of non-renewable energy resources for a gas turbine plant, used natural gas, is proposed. This, in turn, ensures effective planning and increasing the economic efficiency of the enterprise. All this makes it possible to regulate the modes and costs of using fuel during the operation of a gas turbine unit. A study of the operating mode of the gas turbine unit at a constant pressure of 0.1 MPa and a temperature of 10 ° C was carried out, when the optimal operating mode of the gas turbine unit is the combined production of thermal and electrical energy. The choice of the predicting function by which it is better to forecast the use of the energy carrier for the current year has been proposed and substantiated. The scientific novelty of the research lies in the formulation of the substantiation of the conceptual principles for the construction of a mathematical model of the use and accounting of energy consumption based on the use of predictive functions and recommendations are provided on how to rationally use natural resources. The practical significance of the work lies in forecasting and calculating the volume of natural gas consumption (thousand m3) by the enterprise for the next year, and this, in turn, allows us to adjust the gas consumption for the future and make informed decisions on how it is possible to reduce fuel consumption or use it as efficiently as possible.

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