The Investigation of Structure Heterogeneous Joint Welds in Pipelines

Welding joints of dissimilar steels don’t withstand design life. One of the important causes of premature destructions can be the acceleration of steel structural degradation due to cyclic mechanical and thermal gradients. Two zones of tube from steel 12H18N9T, exhibiting the structural instability at early stages of the decomposition of a supersaturated solid austenite solution, were subjected to investigation. Methods of x-ray spectral and structure analysis, micro hardnessmetry were applied for the research. Made the following conclusions, inside and outside tube wall surfaces of hazardous zones in welding joint have different technological and resource characteristics. The microhardness very sensitive to changes of metal structure and can be regarded as integral characteristic of strength and ductility. The welding processes are responsible for the further fibering of tube wall structure, they impact to the characteristics of hot-resistance and long-term strength due to development of ring cracks in the welding joint of pipeline. The monitoring of microhardness and structural phase conversions can be used for control by changes of mechanical properties in result of post welding and reductive heat treatment of welding joints

Possible directions for using bran in heat-power engineering

In connection with the necessity of providing of ecofriendlyness of energy the researches sent to the increase of stake of biomass in fuel and energy balance are actual direction of science and technique. The aim of work is put the study of heating engineering properties of bran and research of possibility of briquetting as it applies to the power use in the stratified fire-box devices. Research methods included standard methodologies of ISO and physical experiment. It is shown as a result of research that bran on the warmth of combustion is comparable with brown coals, but has a less ash-content considerably. However shallow factious composition of bran and caking in the process of ashing will result in high operating costs at their incineration in a natural kind. The variant of the power use of bran is considered as the preforms got the thermal pressing, and the optimal temperature of pressing, equal 150°C. On the example of pressing of shell of cedar nuts possibility of the use of bran is shown as connective, is set here

Research of the opportunity of using bran as a building material

As a result of the functioning of the agro-industrial complex, several million tons of bran that require recycling are annually produced in Russia. At present, there is no resource-efficient way of utilizing bran, which ensures its ecological compatibility and economic efficiency. In this regard, the purpose of the paper is to investigate the possibility of using wheat bran as a building material. The article presents the prerequisites for the construction of low-rise buildings using wheat bran as a building material: an experiment was carried out for the manufacture of bran blocks, and their thermophysical characteristics, maximum crushing strength, and moisture resistance were measured. Building blocks made from bran have a thermal conductivity comparable to the thermal conductivity of wood. The high strength of the bran blocks to squeeze indicates the possibility of their use for the construction of low-rise buildings without any strengthening of their design. However, this blocks exhibit hydrophilic properties, which requires the application of a protective layer. For example, a conventional wood varnish can be use as such a coating

Research of the opportunity of using bran as a building material

As a result of the functioning of the agro-industrial complex, several million tons of bran that require recycling are annually produced in Russia. At present, there is no resource-efficient way of utilizing bran, which ensures its ecological compatibility and economic efficiency. In this regard, the purpose of the paper is to investigate the possibility of using wheat bran as a building material. The article presents the prerequisites for the construction of low-rise buildings using wheat bran as a building material: an experiment was carried out for the manufacture of bran blocks, and their thermophysical characteristics, maximum crushing strength, and moisture resistance were measured. Building blocks made from bran have a thermal conductivity comparable to the thermal conductivity of wood. The high strength of the bran blocks to squeeze indicates the possibility of their use for the construction of low-rise buildings without any strengthening of their design. However, this blocks exhibit hydrophilic properties, which requires the application of a protective layer. For example, a conventional wood varnish can be use as such a coating

Numerical simulation of synthesis gas incineration

The authors have analysed the expediency of the suggested low-grade fuels application method. Thermal processing of solid raw materials in the gaseous fuel, called synthesis gas, is investigated. The technical challenges concerning the applicability of the existing gas equipment developed and extensively tested exclusively for natural gas were considered. For this purpose computer simulation of three-dimensional syngas-incinerating flame dynamics was performed by means of the ANSYS Multiphysics engineering software. The subjects of studying were: a three-dimensional aerodynamic flame structure, heat-release and temperature fields, a set of combustion properties: a flare range and the concentration distribution of burnout reagents. The obtained results were presented in the form of a time-averaged pathlines with color indexing. The obtained results can be used for qualitative and quantitative evaluation of complex multicomponent gas incineration singularities

Biomass Conversion into Solid Composite Fuel for Bed-Combustion

The purpose of this research is the conversion of different types of biomass into solid composite fuel. The subject of research is the heat conversion of biomass into solid composite fuel. The research object is the biomass of the Tomsk region (Russia): peat, waste wood, lake sapropel. Physical experiment of biomass conversion is used as method of research. The new experimental unit for thermal conversion of biomass into carbon residue, fuel gas and pyrolysis condensate is described. As a result of research such parameters are obtained: thermotechnical biomass characteristics, material balances and product characteristics of the heat-technology conversion. Different methods of obtaining solid composite fuel from the products of thermal technologies are considered. As a result, it is established: heat-technology provides efficient conversion of the wood chips and peat; conversion of the lake sapropel is inefficient since the solid composite fuel has the high ash content and net calorific value

Composite Solid Fuel: Research of Formation Parameters

Involving of local low-grade fuels resources in fuel and energy balance is actual question of research in the present. In this paper the possibility of processing low-grade fuel in the solid fuel composite was considered. The aim of the work is to define the optimal parameters for formation of the solid composite fuel. A result of researches determined that dextrin content in the binder allows to obtain solid composite fuel having the highest strength. The drying temperature for the various fuels was determined: for pellets production was 20-80 °C, for briquettes – 20-40 °C

Thermal Energy Consumption in the Heat-Technology Production of Solid Composite Fuel From Low-Grade Raw Materials

An evaluation is made of the thermal energy consumed in the heat-technology production of solid composite fuel from low-grade organic raw materials. It is shown that the heat of decomposition of the organic mass and the combustion of the by-products of heat-technology may be sufficient to cover all the energy needs for processing peat, brown coal and wood chips. Producing solid composite fuel from sapropel requires external resources to compensate for part of the heat consumed. Calculations show that it is possible for the thermal processing of raw materials to proceed autothermally due to the heat of decomposition when the moisture content at the reactor inlet is limited: for peat it should be no more than 35%, 54% for brown coal, and 37% for wood chips. The low heat of decomposition of the sapropel organic mass means that its thermal processing cannot proceed autothermally

Testing the Design of Technical Solutions for Liquid Hydrocarbon Wastes Fire Disposal

The relevance of the work is caused by the need to develop the environmentally friendly heat-generating devices for disposal liquid technological wastes. The main aim of the research is to optimize the constructive implementation of technical solutions for disposal liquid hydrocarbon wastes. Using the software package "Ansys Multiphysics" the authors have simulated the combustion front at various flow conditions and measured reaction rate, temperature and components concentrations in the combustion zone. The results of the investigation have shown that the proposed technical solution has a number of features

Disposal of Liquid Combustible Wastes using Flameless Burners with Porous Carbon Matrix

Two modifications of flameless burners with a carbon porous media in the combustion area were investigated. Kerosene TS-1 and mixtures of highly flammable liquids wastes (HIL) were used as fuel. Experimental data are presented in a graphical form as plot of the burner thermal capacity. Results show capacity for of the developed devices and prove the prospects of disposal of liquid combustible wastes using flameless burners with porous carbon matrix