Analytical estimation of the distribution of thermal neutron flow

The neutron's evaluation of impact on the internal reflector as an example of the plate reactor in single-group approximation. As a result there were obtained wave equations analytical solutions and graphic solution of the formulated problem

The Influence of Gas-Phase Hydrogenation Parameters on the Processes of Activation, Sorption and Accumulation of Hydrogen in the Powder of Pure Titanium

The technique for hydrogenation of powder hydrogen-storage materials based on gas-phase hydrogenation method has been developed in this work. The using of developed technique allow prepare pure titanium powder samples with hydrogen concentration in range from 0.5 to 4 wt.%. It was showed, that pressure increasing from 0.5 to 2 atm at constant temperature 400 °C leads to decreasing of powder activation time from 140 to 15 s. Temperature increasing on 50 °C and more degrees leads to significant decreasing of powder activation time. Pressure increasing from 0.5 to 2 atm leads to increasing of hydrogen sorption rate and concentration in 1.27 and 1.19 times respectively. Temperature increasing from 400 to 550 °C leads to increasing of hydrogen sorption rate in 1.3 times, but decreasing of hydrogen concentration in 1.45 times, which associated with decreasing of hydrogen saturation limit. Optimal values of temperature (400 °C) and pressure (2 atm) for pure titanium powder hydrogenation have been determined

Assessment of Efficiency of Regenerative Heating System of Feed Water for High Temperature Turbine Plant on Decentralized Power Engineering Facilities

The results of theoretical researches on efficiency of air heater use have been presented. The results of the research show the possibility of increase of energy efficiency of electrical power unit on electrical energy consumption by 2% at the initial temperature of steam 1073 K. The possibility of decrease of unit consumption of reference fuel by 4% has been stated

Characteristics of alcohol-coal-water slurries spraying

The aim of this work is to substantiate the efficiency of ethyl or isoamyl alcohol application as the third component of coal-water fuels based on the results of experimental study of coaxial spraying. Studies of alcohols influence on spraying characteristics of coal-water fuels can rarely be found in the literature. Instantaneous fields of fuel droplets velocities in several cross-sections of the jet were determined using Particle Image Velocimetry method. Interferometric Particle Imaging method was used to determine droplets distribution by size in the jet of sprayed coal-water fuel. It was experimentally established that substitution of water (no more than 3 % by weight) in the composition of coal-water slurry by fairly typical alcohols leads to decrease in droplet velocities of alcohol-coal-water slurries in comparison with conventional coal-water fuel by 15-18 %. Concentration of sufficiently small fuel droplets (up to 200 microns) increases by 13.4±0.2 % and by 6.6±0.2 % during atomization of alcohol-coal-water slurries with addition of ethyl and isoamyl alcohol, respectively. Introduction of no more than 5 % by weight of the studied alcohols into the coal-water slurry will reduce the cost of fuel by 15-73 % in comparison with fuel oil. Influence of small additives of ethyl and isoamyl alcohol in the composition of coal-water fuel on spraying characteristics proves the possibility of efficient application of such three-component slurries in thermal power engineering. The results obtained are of practical significance, since they illustrate the possibility of reducing the ignition delay time for droplets of alcohol-coal-water slurries after they are sprayed in the furnaces of boiler units

Comparison of differential and integral methods for coal oxidation kinetic analysis

The influence of two different methods of kinetic analysis on obtained values of kinetic constants of coal oxidation process was studied. The oxidation of T-grade bituminous coal of Kuznetskiy deposit and 2B-grade lignite of Borodinskoe deposit was investigated by means of thermogravimetric analysis. All measurements were carried out with heating rates 2,5, 10, 25 and 40 K/min in temperature range 300-1100 K in air medium. The dependences of activation energy and frequency factor on conversion were obtained using two isoconversional methods: differential method of Freidman and integral method of Kissinger-Akahira-Sunose. The average values of activation energy which were obtained by KAS method were higher by 14.5 % for bituminous coal and 23.3 % for lignite in comparison with values obtained by Freidman method. The same relations were observed for frequency factor values

Numerical Estimation of the Formation Process of Anthropogenic Precipitation in the Atmosphere

The processes of condensation of sulfur trioxide SO[3] and water vapor H[2]O. Sulfuric anhydride is formed in flues of thermal power plants (TPP) by partial oxidation of SO[2] (up to 5 % of the total SO[2]) from the combustion of high-sulfur fuels, and belongs to a class of mild-hazard products. Sulfuric anhydride in the interaction with water vapor, which refers to greenhouse gases, under certain conditions, it forms sulfuric acid

Analytical Estimation of the Central Reflector Impact on Thermal Neutron Flux Density in Research Reactors

In this research was shown an analytical assessment of the impact of the central reflector as an example of spherical reactor in one-group approximation. From the external reflector introduced an effective border that simplifies the mathematical problem of critical task. The validation of the research is done just for one of the IRT-T reactor conditions

Mathematical modeling of the formation of sedimentary acid precipitation in the atmosphere in view of the evaporation of moisture from their surface

The article presents the results of numeric simulation of the formation of sedimentary acid precipitation in the atmosphere taking into account the evaporation of moisture from their surfaces. It is established that the joint condensation of vapors of sulfuric anhydride and water vapor, given the flow of solar energy and the evaporation process significantly slows the growth of drops. The possibility of achieving the underlying surface by the formed sediments is analyzed

Technical project of complex fast cycle heat treatment of hydrogenous coal preparation

Problems of heat-treated milled hydrogenous coal preparation site creation in leading fast cycle heat treatment complex were considered. Conditions for effective use of electrostatic methods of heat-treated milled hydrogenous coal preparation were set. Technical project of heat treatment of milled hydrogenous coal preparation site was developed including coupling of working equipment complex on fast heat treatment and experimental samples of equipment being designed for manufacturing. It was stated that methods of electrical separation are used for heat-treated milled hydrogenous coal preparation with effective ways of organic and mineral components separation. Laboratory test for determination of optimal separation size sent into separators of heat-treated milled hydrogenous coal were made

Steam Pyrolysis of Oil Sludge for Energy-Valuable Products

Experimental studies of the steam pyrolysis of oil sludge were performed using a flow-type pilot plant with 300 kg/h capacity (raw material) to obtain energy-valuable products, such as liquid hydrocarbons (30.4 wt%), semi-coke (39.6 wt%), non-condensable gas-phase compounds (26.5 wt%), and bitumen (3.5 wt%). The pyrolysis process was conducted at a temperature of 650 ° C and with a steam flow rate of 150 kg/h. Liquid hydrocarbons were considered a target product. Comprehensive studies of their physicochemical characteristics, atomization process, droplet ignition, and combustion were carried out. The studied sample had physicochemical characteristics similar to traditional fuel oil (calorific value-42.6 MJ/kg, sulfur content-0.8 wt%). The jet spraying angle was 25° in view of the improved rheological properties of the test sample, with a homogeneous jet structure and a predominant droplet diameter of no more than 0.4 mm. The flame combustion process was accompanied by the formation of microexplosions, the frequency and intensity of which depended on the temperature of the air (Tg = 450-700 °C). This study, in view of its applied nature, is of interest in the design of new installations and technological systems for hydrocarbon pyrolysis