Determining Reliability Parameters for a Closed-Cycle Small Combined Heat and Power Plant

The paper provides numerical values of the reliability parameters for independent power sources within the ambient temperature and output power range corresponding to the operation under the climatic conditions of Eastern Siberia and the Far East of the Russian Federation. We have determined the optimal values of the parameters necessary for the reliable operation of small CHP plants (combined heat and power plants) providing electricity for isolated facilities

Investigation of the Extinguishing Features for Liquid Fuels and Organic Flammable Liquids Atomized by a Water Flow

The processes of heat and mass transfer were investigated experimentally while moving and evaporating the atomized water flow in high-temperature combustion products of typical liquid fuels and organic flammable liquids: gasoline, kerosene, acetone, crude oil, industrial alcohol. We determined typical periods of liquid extinguishing by an atomized water flow of various dispersability. Data of the discharge of extinguishing medium corresponding to various parameters of atomization and duration of using the atomization devices was presented. It is shown that U[m]≈3.5 m/s is a minimal outflow velocity of droplets during moving while passing the distance of 1m in the high-temperature gas medium to stop the combustion of organic liquid

Numerical simulation of heat and mass transfer under the conditions of phase transitions and chemical reaction during ignition of condensed substances by single hot particles

Physical and mathematical models of heat and mass transfer under the conditions of phase transitions and chemical reactions have been developed for the numerical analysis of condensed substances ignition by a single particle (size from 0.5 mm to 5 mm) heated up to high temperature (above 800 K). Liquid, solid and gel fuels were considered as condensed substances. Metal and non-metal particles were used as ignition sources. A heat and mass transfer mathematical model is presented as a system of nonlinear non-stationary differential equations in the private derivatives corresponding to the basic provisions of the general theory of heat transfer in chemical kinetics and free convection. An algorithm for solving differential equations with the corresponding initial and boundary conditions is based on the finite- difference method. The locally one-dimensional method was used to solve difference analogous of differential equations. One-dimensional difference equations were solved using an implicit four-point difference scheme. Nonlinear equations were solved by the iteration method. Mathematical model verification and the assessment of numerical research results reliability was executed by its comparison with experimental results. Also the verification of the law of conservation of energy in the solution area of the ignition problem was performed. Besides, testing of applied numerical methods and the developed silving algorithm on the example of a group of less complex challenges of thermal conduction and thermal convection was held. The minimum parameters of hot particles (temperature, size) and the ignition delay time of condensed substances were determined for local heat sources with different shapes. The influence of thermal conduction, convection and radiative heat transfer mechanisms in the “particle – condensed substance” system was established on the ignition characteristics

Major Contaminants in Industrial and Domestic Wastewater

This paper provides an overview on the type and concentration of the major contaminants in industrial and domestic wastewater. The present study was conducted to analyze and collect data on hazardous substances in wastewater from petrochemical plants, pulp and paper mills, electroplating industries, power plants, and municipal sources (households and small industries)

Evaporation Features of Water Droplets with Typical Subsoil Impurities During the Motion Through High-Temperature Gas Environment: Research Experience at Tomsk Polytechnic University

This paper investigates experimentally the evaporation rate of water droplets with typical subsoil impurities (clay, silt, soil, sand) during the motion through high-temperature gas environment. The experiments were conducted at Tomsk Polytechnic University using high-speed video recording and modern video processing methods. Here, we analyze the influence of the impurity concentration on the intensity of heating and phase changes. The present study defines, how the preheating of impurities affects the completeness of the evaporation of water droplets with impurities. As a result, of studies, we draw the conclusion that it is possible to use water from natural reservoirs without prior preparation for wildfires extinguishing

Using A High-Temperature Flue Gases in the Technology of Combustion Neutralization of Wastewater

This paper provides an analysis of composition of typical polluting contaminants of industrial wastewater. The study suggest industry branches, wastewater of which contains the greatest amount of organic flammable substanses (petroleum и oil). The present study was conducted to analyze an opportunity to replace fuel torch by the high-temperature flow of flue gases in the realization thermal treatment method (combustion neutralization)

Experimental Investigation of Droplet Evaporation of Suspension Based on Water with Subsurface Admixtures in a Flame Area

The influence of typical mixtures (clay, sand, soil, silt) on integral characteristics of droplet evaporation of suspension based on water in high-temperature (about 1100 K) gases was investigated experimentally by the optical methods and high-speed (to 10{5} frames per second) video recording system. The significant intensification of heat up and evaporation of suspension droplets was defined when varying the relative mass fraction of admixtures within the range γ=0−0.1 for a sand, γ=0−0.01 for clay, ground, and silt

Determination of Necessary and Sufficient Operational Conditions of The Sleeve-Type Bearings in Autonomous Power Plants of Ormat Type Under Conditions of Siberia and the Far East

The analysis of integral reliability characteristics for autonomous energy sources in gas pipelines of Russia is carried out. The reasons of the most frequent failures are determined. Recommendations for increase of integral reliability characteristics for autonomous energy sources are formulated

Evaporation Rate of a Liquid Layer Streamlined by Gas Flow in Minichannel

Paper presents the experimental results of mass evaporation rate from ethanol layer surface into a moving in parallel way air flow. Dependences of the mass evaporation rate on the gas velocity, temperature difference between gas and liquid layer, and liquid layer thickness were obtained. The assumption about the formation of the concentration boundary layer at the interface was made. It is found that with increasing the gas flow velocity the gradient of vapor concentration in the gas phase increases; as a result the evaporation rate rises. When changing the liquid layer thickness, the local maximum of evaporation rate was observed, but for 2 mm thickness layer two maxima were found. Probably, it is due the appearance of unstable structures on the liquid surface

Static contact angle versus volume of distilled water drop on micro patterned surfaces

Static contact angle was determined experimentally in the condition of wetting of polished and laser patterned surfaces of stainless steel substrates by distilled water drops with different volumes. In contrast with polished surface, the contact angle was found to depend on drop volume on micro patterned surfaces. In addition, the enhancement of both hydrophilic and hydrophobic properties was observed on laser patterned surfaces