scholarly journals Numerical Analysis of the Combustion of Gases Generated during Biomass Carbonization

Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 181
Author(s):  
Robert Zarzycki ◽  
Rafał Kobyłecki ◽  
Zbigniew Bis
Keyword(s):  
Combustion Process ◽  
Biomass Feedstock ◽  
Safe Operation ◽  
Separate Paper ◽  
Biomass Processing ◽  
Afterburning Chamber ◽  
Combustion Of Gases ◽  
Calculation Results ◽  
Design And Manufacture ◽  
Operational Data

The paper deals with the analysis of the combustion of volatiles evolved during thermolysis (thermal treatment) of biomass feedstock. The process is tailored to produce charcoal (biochar), heat and electricity and the whole system consists of a carbonizer, afterburning chamber and steam recovery boiler. In order to maintain safe operation of the carbonizer the process temperature has to be maintained at an acceptable level and thus the majority of gases evolved during biomass processing have to be combusted outside in the afterburning chamber. In this paper the combustion of those gases in a specially-designed combustion chamber was investigated numerically. The calculation results indicated that the production of the biochar has to be carried out with tight integration and management of the heat produced from the combustion of the volatiles and the emission of CO and methane may be maintained at a low level by optimization of the combustion process. The most promising effects were achieved in cases C4 and C5 where the gas was fed tangentially into the afterburning chamber. The calculation results were then used for the design and manufacture of a pilot reactor—from which the parameters and operational data will be presented and discussed in a separate paper.

FACTOR OF QUALITY FOR PASSIVE NON-TUNABLE BAND-STOP FILTERS

2019 ◽  
pp. 71-74
Author(s):  
N. I. Unru ◽  
E. I. Ashcherbagin
Keyword(s):  
Quality Criterion ◽  
Physical Structure ◽  
Electrical Characteristics ◽  
Central Frequency ◽  
Analytical Expression ◽  
Notch Band ◽  
Attenuation Level ◽  
Calculation Results ◽  
Design And Manufacture

The notion of a quality criterion for non-tunable band-stop filters is introduced, and on the basis of it a comparison of filters with different designs is performed. The quality criterion takes into account the electrical characteristics of the filter and its dimensions, including the volume, the central frequency of the notch band, the level of total losses in the passbands, the width of the notch band by the level of total losses, the width of the notch band by attenuation level. Thus, it allows you to compare the quality of design and manufacture of passive notch filters of various types. The necessary analytical expression is presented, and for a number of variants of filter execution, the corresponding calculation results are given. The stated materials allow us to estimate and optimize the system of interrelated parameters of filters of an arbitrary physical structure.

The Stability Analysis of Slope of Shegang Protecting Dyke

2011 ◽  
Vol 261-263 ◽  
pp. 1841-1845
Author(s):  
Hui Qin Yao
Keyword(s):  
Stability Analysis ◽  
Working Conditions ◽  
Saturation Line ◽  
Dam Safety ◽  
Design Code ◽  
Embankment Dam ◽  
Safe Operation ◽  
Calculation Results ◽  
The Stability ◽  
Reinforcement Design

Appraisal of dam slope safety is essential for security and stability of the dyke that has been constructed for many years. According to the requirements of the appraisal of dam safety, the stability analysis of slope of Shegang dyke has been carried out by using Sweden circular-arc method, Bishop method, Engineer Corps method and Lowe method four methods under many kinds of working conditions and some conditions when the saturation line raising. Combined with the design code form embankment dam, the calculation results can be analyzed. The analysis can show that the security indexes of anti-slide under four kinds of working conditions and some conditions when the saturation line raising meet the requirements of the design code. This can provide basis for the reinforcement design of the dam, which also has a certain directive significance for the safe operation and observation of the dam in the future.

scholarly journals REDUCING THE FORCE RESISTANCE OF STEEL COLUMNS IN INDUSTRIAL BUILDINGS WITH CORROSION DAMAGE DURING OPERATION

2020 ◽  
Vol 8 (4) ◽  
pp. 9-13
Author(s):  
Nina Buzalo ◽  
Ivan Gontarenko ◽  
Boris Chernykhovsky
Keyword(s):  
Experimental Study ◽  
Corrosion Damage ◽  
Building Structure ◽  
Safe Operation ◽  
Metal Structures ◽  
Steel Columns ◽  
Industrial Buildings ◽  
Calculation Results

When conducting inspections of metal structures of industrial buildings, one of the most characteristic damages is revealed - corrosion. To assess the degree of serviceability and the possibility of further safe operation of a building structure or a building and structure, it is necessary to correctly assess the danger of corrosion damage and determine the possibility of further operation. To assess the strength resistance of damaged structures, it is necessary to correctly assess the danger of corrosion damage and determine the possibility of further operation. For this purpose, an experimental study of columns with simulated corrosion damage was carried out and compared with the calculation results according to regulatory recommendations.

scholarly journals Assessment of the technical state and the possibility of its control for the further safe operation of building structures of mining facilities

2019 ◽  
Vol 123 ◽  
pp. 01012
Author(s):  
Yurii Otrosh ◽  
Yevhen Rybka ◽  
Oleksandr Danilin ◽  
Maksym Zhuravskyi
Keyword(s):  
State Assessment ◽  
Ecological Impacts ◽  
Technical State ◽  
Ecological Crisis ◽  
Literary Analysis ◽  
Normal Operation ◽  
Building Structures ◽  
Safe Operation ◽  
Optimal Decisions ◽  
Calculation Results

There are about 200 operating mines in Ukraine, most of which have not been reconstructed for more than 20 years. Modern anthropogenic and ecological impacts are caused by local technogenic catastrophes and the global ecological crisis. The statistical data on the safety of Ukrainian mines were considered. A literary analysis has been made of advanced expertise in the technical state assessment of the building structures. The purpose of the study is to make optimal decisions when constructing, operating and maintaining the buildings. The procedure for assessing the building state is the result of research, the purpose of which is to develop a technique for reliable and operational assessment of the building structures technical state. In this paper, a technique is proposed for inspecting the constructions and assessing their technical state. The maximum efforts in elements of the adapted frame were used for checking calculations and constructional design. The obtained calculation results were used in determining the sufficiency of existing cross section value of the structure elements. According to the calculation results, a conclusion has been made that hardness, stability and rigidity of the frame elements as a whole are ensured; further operation of the building structures is possible providing for the project development to strengthen building structures and to implement the design solutions at the construction site. In order to ensure the continued normal operation, it is necessary to develop a project for strengthening the structures, as well as a project for fire protection of building structures.

scholarly journals Utilization of a zero power reactor for examination of operator influence on reactor control

2020 ◽  
Vol 225 ◽  
pp. 04025
Author(s):  
Tomas Bily ◽  
Darbyshire Alice ◽  
Ondrej Huml
Keyword(s):  
Research Reactor ◽  
Power Reactor ◽  
Reactor Safety ◽  
Safe Operation ◽  
Reactor Control ◽  
Research Reactors ◽  
The United Kingdom ◽  
Human Aspects ◽  
Operational Data ◽  
Insight Into

The reactor operator is an inseparable part of reactor safety and his actions influence the course of the reactor transients. Understanding the operator’s effect on reactor control thus contributes to the knowledge of the safe operation of nuclear reactors. Complementary to studies performed on simulators, or utilizing standard reactor or plant operational data, the dedicated experiments at research reactors can help to improve the insight into human aspects of reactor control. The potential of research reactors to study the human operator aspects of reactor control is broad; the related activities thus may also help to increase the utilization of research reactor facilities. The paper summarizes the considerations that had to be assessed during the implementation of such experiments at the VR-1 research reactor from the viewpoint of the reactor facility. Further, it recapitulates the activities that have been performed in this field at the VR-1 reactor in the collaboration of the Czech Technical University in Prague with the Defence Academy of the United Kingdom in the previous years.

scholarly journals INFLUENCE OF THE COLUMN WEB PANEL BEHAVIOUR ON THE CHARACTERISTICS OF A BEAM-TO-COLUMN JOINT

2013 ◽  
Vol 19 (2) ◽  
pp. 318-324 ◽  
Author(s):  
Alfonsas Daniūnas ◽  
Kęstutis Urbonas
Keyword(s):  
Significant Influence ◽  
Rotational Stiffness ◽  
Component Method ◽  
Short Overview ◽  
Eurocode 3 ◽  
Calculation Results ◽  
Column Joint ◽  
Joint Behaviour ◽  
Frame Construction ◽  
Design And Manufacture

The paper reviews the importance of evaluation of actual joint behaviour during the design and manufacture of frame construction. The authors applied the component method, which is used in Eurocode 3. Additionally, they provided a short overview of beam-to-column joint components. The research focuses on one part of the joint-column web panel. It investigates the influence of the column web panel to the rotational stiffness and design moment resistance of the joint. The article presents several possibilities for stiffening the column web panel plate. Calculation results illustrate the influence of the characteristics of column web panel to the rotational stiffness and design moment resistance of the joint. Calculations were carried out both with an unstiffened and with a stiffened column web panel plates. The results confirmed the expected assumptions, i.e. the column web panel is an essential part of the joint, and its behaviour has a significant influence on the rotational stiffness and design moment resistance of the joint. In all calculations where column web panel was stiffened, the rotational stiffness and design moment resistance of the joint increased.

scholarly journals The Simulation of Different Combustion Stages of Micron-sized Aluminum Particles

2021 ◽  
Vol 11 (4) ◽  
pp. 1774
Author(s):  
Zejun Hu ◽  
Tao Yang ◽  
Zhixun Xia ◽  
Likun Ma ◽  
Mingtai Li ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Gas Phase ◽  
Boiling Point ◽  
Particle Temperature ◽  
Aluminum Particle ◽  
Combustion Process ◽  
Combustion Method ◽  
Combustion Model ◽  
Phase Reaction ◽  
Calculation Results

In this study, a quasi-steady combustion model of an aluminum particle is established, which is more accurate to simulate the physical combustion process. Detailed gas-phase reaction mechanism and surface reaction mechanism are considered. Moreover, the particle temperature is not constant in this work, which is calculated in different combustion stages. The judgement standard of each combustion stage is from observational data in the experiment and the simulation results of combustion durations of each stage, and distribution of ambient temperature and gas-phase species profiles are in good agreement with experimental results. The calculation results show that in the first stage, burning rate of the particle is the fastest, and in the second stage, particle temperature can drop to more than 100 K below the boiling point for the large particles, which is slightly below the boiling point for small ones. As the combustion stage changes, Da number is going to keep going down, which will lead to the transition of combustion method from diffusion-limited control to kinetic-limited control for an aluminum particle.

scholarly journals Improvements in the turbo-engine by replacement of conventional combustion chamber by a pulse combustion chamber

2013 ◽  
Vol 60 (4) ◽  
pp. 481-494
Author(s):  
Damian Łapinski ◽  
Janusz Piechna
Keyword(s):  
Combustion Chamber ◽  
Analytical Model ◽  
Combustion Process ◽  
Constant Volume ◽  
Wave Rotor ◽  
Additional Energy ◽  
Pulse Combustor ◽  
Calculation Results ◽  
Pulse Combustion ◽  
Turbo Engine

Abstract This paper comprises description of the turbo engine and evaluation of its analytical model. The analytical model was created to establish a benchmark for further evaluation of a wave rotor combustor (at constant volume). The wave rotor combustor concept was presented and discussed. Advantages of combustion at constant volume were described as well as the basic turbo engine updates required to reflect pulse combustor application. The calculation results for analytical model of a basic engine, and that equipped with pulse combustor are included in this paper. The paper describes the required changes in the engine structure and construction and the estimated thermodynamic improvements. Axial-type pulse multi-chamber combustion unit increasing the pressure and temperature of gases requires a special additional turbine utilizing additional energy and forming the interface between the standard compressor-turbine unit. Performance calculations done for an existing GTD-350 engine showed that constant-volume combustion process is valuable

Accurate Gas Exchange and Combustion Analysis Directly at the Test Bed

2012 ◽  
Author(s):  
Robert Fairbrother ◽  
Thomas Leifert ◽  
Rudolf Gande ◽  
Georg Salentinig
Keyword(s):  
Gas Exchange ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Measurement Data ◽  
Valve Train ◽  
Data Consistency ◽  
Test Bed ◽  
Combustion Analysis ◽  
Calculation Results ◽  
On Line

Accurate combustion analysis at the test bed is an important tool for the development engineer. It can help engine design, efficiency improvements or emissions reduction by providing instantaneous feedback on the combustion process. It can also provide detailed combustion information to help speed-up the engine calibration process. By implementing shared memory communication, multiple core capability and streamlined calculation techniques, the calculation time of AVL gas exchange and combustion analysis software GCA (Gas Exchange and Combustion Analysis) has been dramatically reduced without significantly decreasing calculation results accuracy. This allows AVL IndiCOM (in combination with AVL GCA) to perform accurate gas exchange and combustion analysis calculations directly and promptly at the test bed. This opens the door to a number of promising new applications by erasing the bridge between measurement data acquisition and post-processing analysis. Increase of measurement data consistency and the reduction of development time are two of the most important benefits of being able to perform “on-line” plausibility checks of measurement data. The strong links connecting AVL GCA calculation results to the measurement data and the redundancy between calculation and measurement for the assessment of some highly relevant engine parameters (e.g. IMEP, air mass flow) can greatly extend the “on-line” plausibility checks functions already available in AVL IndiCom or AVL test bed automation software PUMA. Some passenger car application examples, where valve train flexibility is used to enhance fuel economy or reduce exhaust emissions of internal combustion engines, show that the immediate availability at the test bed of gas exchange related parameters (e.g. internal EGR rate, scavenged mass, mass flows through the valves) supports an intuitive optimization of the valve train parameters.

scholarly journals Pyrolysis oil combustion in the CI engine

2019 ◽  
Vol 179 (4) ◽  
pp. 126-131
Author(s):  
Mariusz CHWIST ◽  
Karol GRAB-ROGALIŃSKI ◽  
Stanisław SZWAJA
Keyword(s):  
Diesel Fuel ◽  
Combustion Process ◽  
Calorific Value ◽  
Injection System ◽  
Pyrolysis Oil ◽  
Compression Ignition Engine ◽  
Common Rail Injection System ◽  
Biomass Processing ◽  
Common Rail Injection ◽  
Ci Engine

Pyrolysis oil obtained from thermal biomass processing (torrefaction and pyrolysis) was used as an additional fuel for the compression-ignition engine equipped with a classic (non-common rail) injection system. The basic fuel used to the engine was regular diesel fuel. The tests were carried out with two content of pyrolysis oil in diesel fuel as follows: 10 and 20% by volume. In addition, the combustion process was investigated in the engine operating only on pyrolysis oil. The test results were based on a comparative analysis, where the diesel fuel was used as the reference fuel. The obtained results indicate that is a real possibility of co-combustion of pyrolysis oil with diesel fuel in the CI engine. On the other hand, a decrease in engine power resulting from the lower calorific value of pyrolysis oil and a greater unrepeatability of engine consecutive work cycles were observed.

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