Laboratory Works on Control Theory Using Scilab/Xcos

Приведен краткий научно-аналитический обзор о современном техническом состоянии и ближайших перспективах развития мировой теплоэнергетики. Рассмотрены основные теплоэнергоустройства, схемы построения и виды тепловых электрических станций (ТЭС). Указаны преимущества и недостатки ТЭС перед другими видами электрических станций, генерирующих тепло и электричество. Приведены основные технические характеристики крупнейших ТЭС Украины. Обозначены существующие проблемные задачи и возможные пути их решения в области теплоэнергетики Украины.

The highly mathematical nature of introductory level vibrations and control theory courses results in students struggling to understand the concepts. Hands-on activity demonstrated in class can help them better understand the concepts. However, there is still an ongoing effort to lower the currently substantial cost of educational laboratory equipment for undergraduate-level engineering courses. Also, with the COVID-19 crisis, the Spring 2020 academic year took an unexpected turn for academics and students all over the world. Engineering faculty who teach laboratories had to move online and instruct from home. Online course preparation takes more time and effort compared to traditionally designed face-to-face courses and was compounded considering the unprecedented situation where many instructors didn't have time to record data from existing lab equipment or record video in their laboratories. In this paper, we present a Matlab Simscape GUI program designed to simulate modeling and control of dynamical systems for vibrations and control theory courses, and their associated laboratories, as one potential solution for online instruction. To complement the simulation program, online classroom and homework activities were designed using a learning sciences approach connecting several critical educational theories which can bolster student motivation, engagement with the material, and overall learning performance. The simulation is presented along with data from 19 students who completed the associated classroom and homework activities. Survey results probing student perceptions about the value of the learning tasks for the simulation were overwhelmingly positive and indicate this approach holds promise in supporting student learning.

New tendencies in publishing data on the thermophysical properties of substances are considered taking as an example water and steam, substances used as the main working fluid in thermal and nuclear power engineering. The advantages and shortcomings of both the traditional approach to publishing data on the properties of substances in hard printed form and the modern one, according to which the data are published in electronic form on Internet websites, are pointed out. The important requirements for publishing data in electronic form are described: the data must be presented in the form of network open and interactive calculations with examples of using them. A critical analysis of the relevant Internet resources is given. Some aspects of the work conducted by the International Association on the Properties of Water and Steam (IAPWS) are described. Particular examples of possible ways in which modern IT-resources on calculating the properties of substances can be set up are given: a hard printed handbook, a calculation program for being installed on a computer, calculation documents for downloading from a website, and using server calculations based on the technologies Mathcad Calculation Server on the website of the Moscow Power Engineering Institute National Research University and SMath on the website of the Elsevier electronic publishing house.

Optimal Protection from Impact, Shock, and Vibration

Robust Gain-Scheduled PSD Controller Design from Educational Perspective

Technical characteristics of an innovative prototype e-learning platform using satellite communications for control theory courses are exposed. A detailed account of all necessary tools and mechanisms is presented enabling real time text, and audio/video based communication between tutors and learners. The provided end-user driven services include: a virtual classroom, offline operation, sharing of applications, private/public chatting, audio/video streaming. In addition a concise description of the pilot network architecture depending on the DVB-RCS standard is presented justifying further the choice of the communications platform. Simulation results concerning the teaching of fundamental issues in Networked Control Theory within the proposed architecture are provided. Connections with hybrid configurations such as wireless terrestrial broadband technologies (DVB-RCS/ WiMAX, DVB-RCS/Wi-Fi) are further analyzed and justified. Finally some conclusive anticipated directions related to the future of modern control courses education in connection with state of art technological advances are explored. AMS (classification): 97U50, 97U70, 97U80, 97D99

Towards a Modern Concept for Teaching Control Engineering

The paper is devoted to the experimental studies of the aerodynamic drag of staggered bundles of helical tubes in order to create highly effective heat exchangers with reduced weight and size. The researches of the aerodynamic drag of staggered bundles of helical tubes at their airflow were carried out on an experimental setup, which is an open-circuit wind tunnel of rectangular cross section and conducted by the method of physical modeling in an isothermal flow, using the data of the drainage selection of static pressures before and after the bundle. The influence of geometric characteristics of helical tubes and parameters of their placement in the bundle on the aerodynamic drag is shown. The comparison of the aerodynamic drag of the bundles of helical and plain tubes of the same outside diameter depending on the incident velocity was conducted. The research results can be used in developing recuperative heat exchangers having high heat-aerodynamic efficiency and applied in thermal power engineering, petrochemical industry, gas compressor units of the gas transportation system ofUkraine. The obtained results can be the basis for aerodynamic calculations in the design of new heat exchangers of helical tubes.

The purification of exhaust gases of some industries by solid wastes of other enterprises is promising and up-to-date in environmental protection. This paper presents the research results on purification of waste gases from ammonia and benzene by wastes from thermal power engineering (fly ash) and chemical industry (secondary polytetrafluoroethylene). Operation of heat power industry plants, which are powered by bituminous coal, results in producing fly ash which is to be stored in special ash ponds. Ash ponds occupy large areas and significantly burden the local ecosystem. Using ash in building, sound-absorbing, and heat insulating materials’ production reduces the volumes of ahs ponds. Fly ash can be used as a base for heterogeneous catalysts. Fly ash can also be used in zeolite production and for soil structure improvement. A number of studies provide positive results of wastewater treatment from oil products and heavy metal ions, as well as absorption of air sulfur(IV) oxide. We propose fly ash using as a sorbent for ammonia adsorbing from exhaust gases in nitric acid and nitrogen fertilizers production. The adsorbate can be applied as a fertilizer for acid soils. Secondary polytetrafluoroethylene is a co-product of polytetrafluoroethylene production. It can be converted into ultradisperse powder with particle sizes of 0.20–1.35 µm by method of exhaustive fluoridation; the powder applies to a sponge material. The resulting sorbent can be used to extract benzene vapors from the exhaust gases of industries using benzene, for example, as a solvent. Compared to activated carbon, the developed sorbent effectively removes benzene vapors from exhaust gases. Over time, the purification efficiency of heated gases decreases to almost zero. Presumably this is due to liquid benzene fraction condensation on the sorbent surface.

Experimental studies of sorption on water treatment from ammonium ions by a calcined sorbent based on ash-and-slag waste from thermal power engineering have been carried out. The calcined sorbent was obtained by calcining samples of ash-and-slag from coal combustion at the Novocherkassk State District Power Plant at a temperature of 600 оC for 30 min. The sorption capacity of a sorbent with a dose of 2.0 g per 50 mL of a model solution, a stirrer speed of 200 rpm, pH 7, and sorption time from 10 to 180 minutes was studied. The influence of the initial concentration of model solutions with the content of ammonium ions 5, 20, 50 and 100 mg/L on the amount of adsorption and treatment efficiency was studied. The highest treatment efficiency of 60% was obtained for an initial concentration of ammonium ions in a solution of 20 mg/L. Processing of experimental data was carried out according to the models of pseudo-first, pseudo-second-order and intra-particle diffusion kinetics. The best description of the experimental data was obtained using the pseudo-first order model, which has the highest value of the coefficient of determination. The adsorption equilibrium in the system ammonium ions – calcined sorbent was studied for the initial concentration of ammonium ions in solution: 5, 20, 30, 50, 100, 200, 300 mg/L. Processing of experimental data on equilibrium was carried out on the basis of two-parameter adsorption isotherms: Langmuir, Freindlich and Temkin. The value of the coefficient of determination according to the Langmuir isotherm is the largest R2 = 0.9904. Dependences between the cleaning efficiency at adsorption equilibrium and the initial concentration of ammonium ions in solution for the system ammonium ions – calcined sorbent are obtained. With an increase in the initial concentration of ammonium ions in the solution, the treatment efficiency at low initial concentrations increases, and decreases with increasing concentration.

Human factor management tool while performing high-risk work in thermal power engineering

The monograph presents methods for calculating the dehydration of wet granular materials in industrial centrifuges, filter presses and vacuum filters under the influence of gravitational forces, as well as by purging the granular layer with dry air with elevated temperature; physical and mathematical models of gas absorption and the theory of capturing submicron dust by condensation in foam, centrifugal bubbling apparatus and hollow nozzle scrubbers, packing columns and tubular absorbers; physical and mathematical models of dry adsorption of gases in packing columns and flues by injecting a dispersed adsorbent into the flow are presented, a method for determining the phase equilibrium constants of sorption processes based on the developed models is proposed; physical and mathematical modeling and analysis of the combustion process of dispersed solid ash fuel in a four-stage cyclone gorenje is carried out. the furnace. It can be useful in the educational process for a number of specialties, in particular thermal power engineering, chemical-technological, metallurgical profiles, environmentalists, as well as for researchers and graduate students and in engineering practice.

Recently, prospective direction of the combustion theory development is the preparation of fuel compositions and study of the composite fuels ignition characteristics, for example, in the form of emulsions and suspensions. Such fuels and their combustion processes are characterized by higher environmental, energy, economic, and operational properties. Of great interest is the use of gel fuels prepared by thickening emulsions and suspensions to the state of elastically deformable materials for the aerospace industry and thermal power engineering. Gel fuels have advantages over widespread liquid fuels in environmental and fire safety aspects of storage processes, transportation, and combustion.

Experimental and numerical study of coal dust ignition by a hot particle

Abstract. Thermal power engineering takes one of the first places by the scale of the impact on the environment. Thermal power plant emissions are mainly deposited on the ground. Soil compounds, binding heavy metal ions (НM) for a long time, prevent their migration. The buffer capacity of the soil for metals depends on many factors: soil composition, acidity, complexity, oxidation–reduction,sorption–desorption, etc. Examination of the HM content in the soils is necessary for monitoring the environment, its protection from pollution. One of the largest pollutants in Kharkiv region is Zmiiv TPP. The goal of the work is to find out peculiarities of heavy metal contamination of the soil near the Zmiiv TTP and develop recommendations on improving the situation. In order to reach the goal, the following tasks have been solved: features of accumulation of various heavy metals in the soils have been specified, dependence between the soils pH and presence of certain chemical elements in them has been defined, dependance between the content of contamination and development of slow soluble compounds in the soil has been studied. Research methodology. The main principle of control for soil contamination is checking of concentration compliance with the established maximum permissible concentration (MPC) and approximate permissible concentration (APC). HM concentrations in the aqueous extract from the soil were determined by the atomic-emission spectral analysis, atomic absorption analysis and by the method of capillary electrophoresis. To determine the composition of the solid inorganic part of soils X-ray phase analysis was performed. Results of research. It is established that the most polluted areas are located within 10 km from TPP. The most disseminated pollutants in the area are Cu, Br, Co, V, Cr. The soils of the Siverskyi Donets Basin retain Cu, Zn and Pb ions to a large extent. Scientific novelty. Metals V, Cr are anionogenics, acid residues are formed in slightly alkaline soils and together with HM they form insoluble or slightly soluble compounds leading to their accumulation. Compounds SrCrO4, SrCr2O7, Sr(VO3)2, Zn2V2О7, Zn3(VО4)2, Zn(VО3)2 were found in the soils. Based on the determination of the coefficients of poly-elemental contamination, it is shown that maximum concentrations of HM are higher and variations of concentrations are wider except Pd, Zn and Cd in the soils with high humus, buffering and ability to form complexes with metal ions. The correlation relationships between pH, macro- and і microelements in various soils are determined. The highest correlation coefficient is between Al concentration and pH (0.6-0.9). Practical significance. Recommendations have been developed to reduce the level of soil contamination near Zmiiv TPP: reconstruction of the boiler unit, installation of an electrostatic precipitator to collect ash, using ash and slag waste in the production of Portland cement, liming soil for discrimination of HM.