scholarly journals Autonomous Power Station Based on Rotary-Vane Engine with an External Supply of Heat

2015 ◽  
Vol 2 ◽  
pp. 97
Author(s):  
Mikhail Andreev ◽  
Yuriy Zhuravlev ◽  
Yuriy Lukyanov ◽  
Leonid Perminov
Keyword(s):  
Mathematical Model ◽  
Angular Displacement ◽  
Structural Complexity ◽  
Thermodynamic Cycle ◽  
State University ◽  
Physical Processes ◽  
Working Medium ◽  
Heat Intake ◽  
External Combustion ◽  
The Mathematical Model

Rotary-vane engine (RVE) with an external supply of heat is an aggregate consisting of two modules with a common output shaft, the heating device (heater) of working medium and the cooling device (cooler) of working medium, which connected with inlet and outlet ports of modules by system of pipeworks. Each module has two rotors with two vanes on each. Between the corresponding plane surfaces of the four vanes four working volumes are formed wherein thermodynamic cycle steps: ingress, compressing, heat intake, expansion stroke, discharge, outward heat transmission are going simultaneously. The angular displacement of modules relative to one another occurs pumping the working medium through the heater and cooler, which allows the conversion of thermal energy into mechanical work. Design features of the RVE with an external supply of heat allows create a closed gas-vapor cycle. The main specified advantages of the RVE with an external supply of heat are: fewer noxious emissions, multifuel capability, high motor potential (service life). Different problems of creation external combustion engines such as structural complexity of construction units, absence of adequate mathematical model of designed RVE with an external supply of heat are also pointed. The construction of the RVE with an external supply of heat developed in Pskov Polytechnic Institute (now the Pskov State University), the operation concept of the engine, the physical processes in the chamber modules RVE with an external supply of heat during each step and the mathematical model describing the physical processes proceeding in chamber RVE with an external supply of heat modules are considered.

Influence of Imperfections in the Working Media on Diesel Engine Indicator Process: Part 2 — Results

1998 ◽  
Author(s):  
Stanislav N. Danov ◽  
Ashwani K. Gupta
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
High Pressures ◽  
Combustion Process ◽  
Ideal Gas ◽  
Working Medium ◽  
High Pressures And Temperatures ◽  
Specific Heat Capacities ◽  
Working Media ◽  
The Mathematical Model

Abstract In the companion Part 1 of this two-part series paper several improvements to the mathematical model of the energy conversion processes, taking place in a diesel engine cylinder, have been proposed. Analytical mathematical dependencies between thermal parameters (pressure, temperature, volume) and caloric parameters (internal energy, enthalpy, specific heat capacities) have been obtained. These equations have been used to provide an improved mathematical model of diesel engine indicator process. The model is based on the first law of thermodynamics, by taking into account imperfections in the working media which appear when working under high pressures and temperatures. The numerical solution of the simultaneous differential equations is obtained by Runge-Kutta type method. The results show that there are significant differences between the values calculated by equations for ideal gas and real gas under conditions of high pressures and temperatures. These equations are then used to solve the desired practical problem in two different two-stroke turbo-charged engines (8DKRN 74/160 and Sulzer-RLB66). The numerical experiments show that if the pressure is above 8 to 9 MPa, the working medium imperfections must be taken into consideration. The mathematical model presented here can also be used to model combustion process of other thermal engines, such as advanced gas turbine engines and rockets.

A Differential Equation of the First Law of Thermodynamics for Modeling the Indicator Process of a Diesel Engine

1997 ◽  
Author(s):  
Stanislav N. Danov
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
High Pressure And Temperature ◽  
First Law Of Thermodynamics ◽  
Ideal Gases ◽  
Working Medium ◽  
Engine Cylinder ◽  
Computing Procedure ◽  
The Mathematical Model ◽  
Good Agreement

Abstract Several improvements to the mathematical model of the indicator process taking place at a diesel engine cylinder are proposed. The thermodynamic behavior of working medium is described by the equation of state, valid for real gases. Mathematical dependencies between thermal parameters (P, T, v) and caloric parameters (u, h, cv, cp) have been obtained. An improved mathematical model, based on the first law of thermodynamics, has been developed, taking into account working medium imperfections. The numerical solution of the simultaneous differential equations is made by a method of Runge-Kutta type. The computing procedure is iterative. Calculations in respect to the caloric parameters (u, h, cv and cp) for various gases under pressure up to 25 MPa and temperature up to 3000°C have been carried out. The results show, that there are significant differences between the values, calculated by equations for ideal gases, and the proposed equations for real gases under high pressure and temperature. Actual applied problems for two-stroke turbocharged engines Sulzer-RLB66 and 8DKRN 74/160 have been solved. The comparison between the experimental data and numerical results show very good agreement. The numerical experiments show that if the pressure is above 8–9 MPa, the working medium imperfections must be taken into consideration.

Simulation Model of the Thermodynamic Cycle of a Three-Cylinder Double-Acting Steam Engine

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Evzen Thoendel
Keyword(s):  
Mathematical Model ◽  
Thermodynamic Cycle ◽  
Steam Pressure ◽  
Heat Energy ◽  
Point Of View ◽  
Steam Engine ◽  
Pressure Reduction ◽  
Software Environment ◽  
The Mathematical Model ◽  
Pressure Reduction Station

Today, steam engines are used for special purposes only, for example to reduce steam pressure in pressure reduction stations, where they replace the traditional and inefficient throttling process. Throttling is the most used way to control the pressure in steam reduction stations. This way is unsatisfactory from the economical point of view, because the exergy is lost uselessly. It is a part of heat energy that can perform a work. The better way of a pressure reduction is an expansion in a backpressure turbine or in a steam engine by simultaneous transformation of the heat energy into electricity (cogeneration). This article describes the design and implementation of the mathematical model of a steam engine used as pressure regulator in a pressure reduction station. The present model is a part of a comprehensive mathematical model of a cogeneration unit and also a part of the author's doctoral thesis. The model assumes detailed mathematical description of physical processes in a steam engine and implementation in an MATLAB-SIMULINK software environment.

scholarly journals COMPUTATION OF HEAT AND MASS DISTRIBUTION IN SINTER LAYER BASED ON PDEs

2018 ◽  
pp. 226-233
Author(s):  
Kyrylo S. Krasnikov
Keyword(s):  
Mathematical Model ◽  
Iron Ore ◽  
Scientific Literature ◽  
Time Dependency ◽  
Physical Processes ◽  
Horizontal Movement ◽  
Ore Pellets ◽  
Air Movement ◽  
Simple Chemical ◽  
The Mathematical Model

The article presents mathematical model of interconnected physical processes on sintering machine during agglomeration of iron ore pellets. The mathematical model uses a system of partial differential equations. Velocity of the horizontal movement of the layer and the vertical velocity of the air movement through the layer as well as phase transition and simple chemical reactions of pellet and air components are taken into account in this model. The purpose of simulation is to determine the time dependency of sinter temperature distributed along the length and height of the layer and then define rational parameters for optimization of metallurgical process. In addition, concentration of sinter and gas components distributed along the height of the layer is computed. The numerical experiment shows that temperature front, which is lower in the layer cross-section, is sharper in comparison with the upper front, where the obtained agglomerate is cooled, as water requires a considerable amount of energy to evaporate. The obtained results are qualitatively consistent with the data in scientific literature.

scholarly journals Numerical investigation on the effect of the vessel rolling angle and period on the energy harvest

2021 ◽  
pp. 147509022110024
Author(s):  
Boyang Li ◽  
Rui Zhang ◽  
Qingyong Yang ◽  
Baoshou Zhang ◽  
Longjin Wang
Keyword(s):  
Mathematical Model ◽  
Angular Displacement ◽  
Mechanical Energy ◽  
Average Power ◽  
Energy Harvest ◽  
Matlab Simulation ◽  
Rolling Angle ◽  
Instantaneous Power ◽  
The Mathematical Model ◽  
Gravity Component

In order to harvest effectively the mechanical energy produced in the process of vessel rolling, an energy harvest unit installed on the vessel is designed to utilize the mechanical energy. Firstly, the structure of the unit is proposed, and the relevant mathematical model is established. The solution of the mathematical model is given by Newmark- β method. Then, the influence of vessel rolling period and angle on the unit’s power and related parameters of the block is studied by MATLAB simulation. The results show that when the vessel is rolling, the energy harvest unit has a considerable power generation effect, the rolling period and angle of the vessel have a great impact on the power of the unit. Under the condition of the same period, the vessel with a larger rolling angle corresponds to larger peak gravity component, peak angular displacement, peak linear velocity of block and average power of the unit. In addition, under the same sea conditions, numerical simulations carried out on the rolling motion of 70,000, 100,000, and 150,000-ton bulk vessels and related parameters of the unit, indicating that the instantaneous power of the unit is not uniform in actual sea conditions, but it can output power continuously.

scholarly journals Simulation of Electromagnetic-Acoustic Heating of the Oil Layer in Laboratory Conditions

2021 ◽  
Vol 16 (1) ◽  
pp. 109-116
Author(s):  
Gulnara R. Izmailova
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
High Frequency ◽  
Additional Term ◽  
Oil Reservoir ◽  
Combined Effects ◽  
Physical Processes ◽  
The Mathematical Model ◽  
Account Heat

This paper describes an experiment to study the combined effects of high-frequency electromagnetic and acoustic fields on a model of an oil reservoir. A mathematical model is described that describes the physical processes that occur in the reservoir. The heat equation takes into account heat transfer with the environment by introducing an additional term. The largest discrepancy between theoretical and experimental data does not exceed 28%. Qualitative coincidence of theoretical and experimental curves indicates the adequacy of the mathematical model.

MATHEMATICAL MODEL OF QUALITY ASSESSMENT OF CONTACT WORK IN E-LEARNING BASED ON WEBINARS

2019 ◽  
pp. 42-53
Author(s):  
A. N. Poletaykin ◽  
Yu. V. Shevtsova ◽  
V. V. Podkolzin ◽  
E. G. Strukova
Keyword(s):  
Mathematical Model ◽  
Information Science ◽  
Estimation Procedure ◽  
State University ◽  
E Learning ◽  
The Mathematical Model ◽  
Adequate Management ◽  
Quality Of Contact

The article deals with the problems of the quality of contact work in the implementation of training using distance educational technologies. The mathematical model of estimation of quality of the contact work realized by means of webinars is developed for a research of this problem. The analysis of the tasks arising at the organization of webinars is carried out, among which the problem of determination of the actual quality of webinars is recognized as one of essential, which is necessary for making adequate management decisions to improve the quality of contact work carried out through webinars. Three groups of the factors defining quality of distance learning in general were revealed for the solution of this problem: the quality of educational content, the professionalism of teachers, and the interaction of the teacher and student. The research of quality of webinars conducted by authors in 2018 in Siberian State University of Telecommunications and Information Science have allowed to define and formalize 31 indicators of quality of a webinar and 7 indicators of competence of a webinar leader, on the basis of which the mathematical model is developed. The model allows to carry out expert and expeditious estimation of the specified indicators, thereby to realize integrated differential approach to estimation of the aspects of quality of contact work in the form of a webinar. Also, mathematical solutions of increasing efficiency of the model implementation by applying neural network method to the estimation procedure for the majority of indicators are proposed, which allows obtaining adequate estimates of indicators without the participation of experts.

scholarly journals Code for calculating wave technology of thermal-gas-chemical formation treatment for oil recovery enhancement

2021 ◽  
Vol 1201 (1) ◽  
pp. 012028
Author(s):  
M N Kravchenko ◽  
V E Kroshilin ◽  
N N Dieva
Keyword(s):  
Mathematical Model ◽  
Oil Recovery ◽  
Oil And Gas ◽  
Field Research ◽  
High Viscosity ◽  
State University ◽  
Software Products ◽  
Russian State ◽  
Porosity And Permeability ◽  
The Mathematical Model

Abstract Transition to the development of hard-to-recover hydrocarbons, including in regions the far north, is fraught with difficulties in using classical technologies development. This is due to the low porosity and permeability of the reservoirs, high viscosity of the formation fluid and the manifestation of abnormal (non-Newton) properties of hydrocarbon fluids. In this regard, for more than ten years, pilot field research (FPI) in terms of the selection and optimization of technologies for collectors of complex structures. Since 2011, at the departments of the underground hydromechanics of Gubkin Russian State University of Oil and Gas (NRU) and gas wave dynamics of the Lomonosov Moscow State University, research is underway on the use of thermogas-chemical method with an injection of a binary mixture to stimulate the inflow. Since 2011, several settlement codes of different levels were created, which allowed carrying out support (pilot) in various fields. Based software products managed to evaluate the characteristics in the chemical reaction zone decomposition of the working chemical composition, evaluate safe regimes, excluding damage to the wellbore and assess the prolongation of the effect. Published more than 20 works (including patents) with the participation of the authors. Since 2019 the mathematical model is significantly complicated: the multiphase and non-isothermality of the process, non-uniformity of the flow. Currently established generalizing code, in the mathematical model of which is additionally taken into account different compressibility of phases and rheological properties of fluids, which allows more fine-tune the computational code for the type of a specific field, taking into account its geological features and damage to the bottomhole zone in the previous stages of development.

scholarly journals Examination of the Summer Stratification

1978 ◽  
Vol 9 (2) ◽  
pp. 105-120 ◽  
Author(s):  
Urban Svensson
Keyword(s):  
Mathematical Model ◽  
Temperature Distribution ◽  
Thermal Structure ◽  
Qualitative Evaluation ◽  
Lake Morphometry ◽  
Physical Processes ◽  
Vertical Temperature ◽  
Seasonal Stratification ◽  
Vertical Temperature Distribution ◽  
The Mathematical Model

The seasonal stratification in lakes is examined by a qualitative evaluation of important physical processes and with the aid of a mathematical model. From the description of the physical processes it is realized that the observed vertical temperature distribution is the synthesis of a number of complicated and inter-dependent phenomena. The mathematical model is employed for a quantitative estimate of the importance of lake morphometry and transparency. It is found that the vertical variation of horizontal area and variations in transparency strongly influence the thermal structure of a lake. Measurements of the temperature distribution in Lake Velen are compared to predictions obtained by the mathematical model. The agreement is found to be satisfactory and it is concluded that the mathematical model provides a realistic way of studying and predicting the summer stratification.

Influence of Imperfections in Working Media on Diesel Engine Indicator Process

2000 ◽  
Vol 123 (1) ◽  
pp. 231-239 ◽  
Author(s):  
S. N. Danov ◽  
A. K. Gupta
Keyword(s):  
Mathematical Model ◽  
High Pressure ◽  
Diesel Engine ◽  
High Pressures ◽  
Ideal Gas ◽  
Working Medium ◽  
Engine Cylinder ◽  
Specific Heat Capacities ◽  
Working Media ◽  
The Mathematical Model

Several improvements to the mathematical model for the indicator process in a diesel engine cylinder are proposed. The thermodynamic behavior of working media is described by the equation of state valid for real gases. Analytical mathematical dependencies between thermal parameters (pressure, temperature, volume) and caloric parameters (internal energy, enthalpy, specific heat capacities) have been obtained. These equations have been applied to the various products encountered during the burning of fuel and the gas mixture as a whole in the engine cylinder under conditions of high pressures. An improved mathematical model, based on the first law of thermodynamics, has been developed by taking into account imperfections in the working media that appear under high pressures. The numerical solution of the simultaneous differential equations is obtained by Runge–Kutta-type method. The mathematical model is then used to solve the desired practical problems in two different two-stroke turbo-charged engines: 8DKRN 74/160 and Sulzer-RLB66. Significant differences between the values calculated using ideal gas behavior and the real gas at high-pressure conditions have been found. The numerical experiments show that if the pressure is above 8 to 9 MPa, the imperfections in working medium must be taken into consideration. The results obtained from the mathematical dependencies of the caloric parameters can also be used to model energy conversion and combustion processes in other thermal machines such as advanced gas turbine engines with high-pressure ratios.

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