scholarly journals Study on slagging characteristics and prevention of biomass briquette

2021 ◽  
Vol 248 ◽  
pp. 01006
Author(s):  
Ren Xiaoping ◽  
Liu Fang ◽  
Tang Xintong ◽  
Yang jing ◽  
Yang song ◽  
...  
Keyword(s):  
High Efficiency ◽  
Combustion Process ◽  
Scientific Basis ◽  
Combustion Characteristics ◽  
Furnace Temperature ◽  
Excess Air ◽  
Fuel Layer ◽  
Temperature Excess ◽  
Reduction Measure ◽  
And Control

It is a high efficiency，energy-saving and emission reduction measure to replace coal with biomass briquette fuel in a layer combustion furnace, but in the combustion process, the serious slagging problem has been restricted the promotion of biomass fuel. By analyzing the combustion characteristics of biomass briquette, the ash fusion characteristics and slagging mechanism, combined with the combustion characteristics of a layer combustion furnace, the important influence of key combustion parameters (furnace temperature, excess air, fuel layer thickness) on the slagging in the furnace is obtained, which provides a scientific basis for taking measures to prevent and control the slagging in the design and operation of the biomass briquette layer combustion furnace.

EFFECT OF METALLIC FUEL NATURE ON COMBUSTION CHARACTERISTICS OF AMMONIUM PERCHLORATE / BINDER / METAL COMPOSITE SOLID PROPELLANTS

2020 ◽  
Author(s):  
V. A. Poryazov ◽  
◽  
O. G. Glotov ◽  
V. A. Arkhipov ◽  
G. S. Surodin ◽  
...  
Keyword(s):  
Ammonium Perchlorate ◽  
Combustion Process ◽  
Experimental Information ◽  
Combustion Characteristics ◽  
Transformer Oil ◽  
Metal Composite ◽  
Butadiene Rubber ◽  
Solid Propellants ◽  
Metallic Fuel ◽  
Composite Solid Propellants

The goal of this research is to obtain experimental information about combustion characteristics of the composite propellant containing various metallic fuels. The propellant formulations contained two fractions of ammonium perchlorate (64.6%), inert binder (19.7%) - butadiene rubber SKD plastized with transformer oil, and metal fuel (15.7% of aluminum ASD-4, ASD-6, Alex; boron; aluminum diboride; aluminum dodecaboride; some mixtures of above listed ingredients). Experimental information will be used further as a background to develop the physical and mathematical model of combustion process.

Modeling and Experiment on Combustion Characteristics for Biomass Rotary Burner

2020 ◽  
Vol 04 ◽  
Author(s):  
Guohai Jia ◽  
Lijun Li ◽  
Li Dai ◽  
Zicheng Gao ◽  
Jiping Li
Keyword(s):  
Combustion Chamber ◽  
Combustion Temperature ◽  
Combustion Efficiency ◽  
Middle Part ◽  
Combustion Characteristics ◽  
Maximum Temperature ◽  
Excess Air ◽  
Element Simulation ◽  
Excess Air Coefficient ◽  
Secondary Air

Background: A biomass pellet rotary burner was chosen as the research object in order to study the influence of excess air coefficient on the combustion efficiency. The finite element simulation model of biomass rotary burner was established. Methods: The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in steady condition and the effects of excess air ratio on pressure field, velocity field and temperature field was analyzed. Results: The results show that the flow velocity inside the burner gradually increases with the increase of inlet velocity and the maximum combustion temperature is also appeared in the middle part of the combustion chamber. Conclusion: When the excess air coefficient is 1.0 with the secondary air outlet velocity of 4.16 m/s, the maximum temperature of the rotary combustion chamber is 2730K with the secondary air outlet velocity of 6.66 m/s. When the excess air ratio is 1.6, the maximum temperature of the rotary combustion chamber is 2410K. When the air ratio is 2.4, the maximum temperature of the rotary combustion chamber is 2340K with the secondary air outlet velocity of 9.99 m/s. The best excess air coefficient is 1.0. The experimental value of combustion temperature of biomass rotary burner is in good agreement with the simulation results.

scholarly journals Research on the Operating Characteristics of Hydraulic Free-Piston Engines: A Systematic Review and Meta-Analysis

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3530
Author(s):  
Fukang Ma ◽  
Shuanlu Zhang ◽  
Zhenfeng Zhao ◽  
Yifang Wang
Keyword(s):  
Systematic Review ◽  
High Efficiency ◽  
Meta Analysis ◽  
Combustion Process ◽  
Research Progress ◽  
Future Research ◽  
Operating Characteristics ◽  
Piston Engine ◽  
Free Piston ◽  
Free Piston Engine

The hydraulic free-piston engine (HFPE) is a kind of hybrid-powered machine which combines the reciprocating piston-type internal combustion engine and the plunger pump as a whole. In recent years, the HFPE has been investigated by a number of research groups worldwide due to its potential advantages of high efficiency, energy savings, reduced emissions and multi-fuel operation. Therefore, our study aimed to assess the operating characteristics, core questions and research progress of HFPEs via a systematic review and meta-analysis. We included operational control, starting characteristics, misfire characteristics, in-cylinder working processes and operating stability. We conducted the literature search using electronic databases. The research on HFPEs has mainly concentrated on four kinds of free-piston engine, according to piston arrangement form: single piston, dual pistons, opposed pistons and four-cylinder complex configuration. HFPE research in China is mainly conducted in Zhejiang University, Tianjin University, Jilin University and the Beijing Institute of Technology. In addition, in China, research has mainly focused on the in-cylinder combustion process while a piston is free by considering in-cylinder combustion machinery and piston dynamics. Regarding future research, it is very important that we solve the instabilities brought about by chance fluctuations in the combustion process, which will involve the hydraulic system’s efficiency, the cyclical variation, the method of predicting instability and the recovery after instability.

Stirling Engine Technology for Parabolic Dish-Stirling System Based on Concentrating Solar Power (CSP)

2015 ◽  
Vol 785 ◽  
pp. 576-580 ◽  
Author(s):  
Liaw Geok Pheng ◽  
Rosnani Affandi ◽  
Mohd Ruddin Ab Ghani ◽  
Chin Kim Gan ◽  
Jano Zanariah
Keyword(s):  
High Efficiency ◽  
Combustion Engine ◽  
Renewable Energy Sources ◽  
Stirling Engine ◽  
Energy Sources ◽  
Heat Engines ◽  
Stirling Engines ◽  
Parabolic Dish ◽  
Mechanical Devices ◽  
And Control

Solar energy is one of the more attractive renewable energy sources that can be used as an input energy source for heat engines. In fact, any heat energy sources can be used with the Stirling engine. Stirling engines are mechanical devices working theoretically on the Stirling cycle, or its modifications, in which compressible fluids, such as air, hydrogen, helium, nitrogen or even vapors, are used as working fluids. When comparing with the internal combustion engine, the Stirling engine offers possibility for having high efficiency engine with less exhaust emissions. However, this paper analyzes the basic background of Stirling engine and reviews its existing literature pertaining to dynamic model and control system for parabolic dish-stirling (PD) system.

Effect Of Equivalent Ratio (ER) On the Flow and Combustion Characteristics in A Typical Underground Coal Gasification (UCG) Cavity

2021 ◽  
Vol 86 (2) ◽  
pp. 28-38
Author(s):  
Arup Kumar Biswas ◽  
Wasu Suksuwan ◽  
Khamphe Phoungthong ◽  
Makatar Wae-hayee
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Gas Flow ◽  
Coal Gasification ◽  
High Efficiency ◽  
Combustion Characteristics ◽  
Raw Material ◽  
Underground Coal Gasification ◽  
Equivalent Ratio ◽  
Rubble Pile

Underground Coal Gasification (UCG) is thought to be the most favourable clean coal technology option from geological-engineering-environmental viewpoint (less polluting and high efficiency) for extracting energy from coal without digging it out or burning it on the surface. UCG process requires only injecting oxidizing agent (O2 or air with steam) as raw material, into the buried coal seam, at an effective ratio which regulates the performance of gasification. This study aims to evaluate the influence of equivalent ratio (ER) on the flow and combustion characteristics in a typical half tear-drop shape of UCG cavity which is generally formed during the UCG process. A flow modeling software, Ansys FLUENT is used to construct a 3-D model and to solve problems in the cavity. The boundary conditions are- (i) a mass-flow-inlet passing oxidizer (in this case, air) into the cavity, (ii) a fuel-inlet where the coal volatiles are originated and (iii) a pressure-outlet for flowing the product Syngas out of the cavity. A steady-state simulation has been run using k-? turbulence model. The mass flow rate of air varied according to an equivalent ratio (ER) of 0.16, 0.33, 0.49 and 0.82, while the fuel flow rate was fixed. The optimal condition of ER has been identified through observing flow and combustion characteristics, which looked apparently stable at ER 0.33. In general, the flow circulation mainly takes place around the ash-rubble pile. A high temperature zone is found at the air-releasing point of the injection pipe into the ash-rubble pile. This study could practically be useful to identify one of the vital controlling factors of gasification performance (i.e., ER impact on product gas flow characteristics) which might become a cost-effective solution in advance of commencement of any physical operation.

Experimental Study on Combustion Characteristics of Biomass and Coal Blended

2013 ◽  
Vol 805-806 ◽  
pp. 200-207
Author(s):  
Bing Zhang ◽  
Guang Wu Lu
Keyword(s):  
Particle Size ◽  
Ignition Temperature ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Combustion Characteristic ◽  
Thermogravimetric Analyzer ◽  
Rate Of Combustion ◽  
Mixing Proportion ◽  
Biomass Particle Size ◽  
Obvious Weight Loss

Under different conditions,combustion characteristics of the single biomass,the single coal and the mixture of biomass and coal were analyzed by using thermogravimetric analyzer. Combustion characteristic parameters of the sawdust,the rice husk,the rice straw and the Baisha coal of Leiyang were studied,including ignition temperature,the maximum rate of combustion temperature,the burnout temperature and so on. The experimental results show that the biomass burning temperature is lower than the Baisha coal and there are two obvious weight loss phases in the combustion process of the biomass. However,there is only one in the coal. The ignition temperature and time of the coal can be reduced ,the temperature range of the entire combustion can be extended,the coal can be burnout more well and the fuel combustion characteristic can be optimized by blending combustion. With the increase of biomass mixing proportion, the ignition temperature of mixing samples was decreased more obviously. Moreover,when the biomass particle size becomes R200,compared with R90 particle size under the same blending ratio,its ignition temperature is more lower.

Numerical Simulation on Moisture Influence to MSW Combustion

2014 ◽  
Vol 1006-1007 ◽  
pp. 181-184
Author(s):  
Zhu Sen Yang ◽  
Xing Hua Liu ◽  
Shu Chen
Keyword(s):  
Numerical Simulation ◽  
Moisture Content ◽  
Flue Gas ◽  
Combustion Process ◽  
Average Temperature ◽  
Excess Air ◽  
Heat Value ◽  
Moisture Influence ◽  
Excess Air Coefficient ◽  
Combustible Gases

The combustion process of municipal solid waste (MSW) in a operating 750t/d grate furnace in Guangzhou was researched by means of numerical simulation. The influence of MSW moisture content on burning effect was discussed. The results show that: with the moisture content dropped from 50% to 30%, the heat value could be evaluated from 13.72% to 54.91% and the average temperature in the furnace could be promoted 90-248°C. However, the combustible gases and particle in the flue gas of outlet would take up a high proportion since lacking of oxygen would lead to an incomplete combustion. The excess air coefficient should be increased to 2.043~2.593 in order to ensure the flue gas residence time more than 2s and temperature in the furnace higher to 800°C.

scholarly journals Hybrid Rule-Based Solution for Phishing URL Detection Using Convolutional Neural Network

2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Youness Mourtaji ◽  
Mohammed Bouhorma ◽  
Daniyal Alghazzawi ◽  
Ghadah Aldabbagh ◽  
Abdullah Alghamdi
Keyword(s):  
Deep Learning ◽  
High Efficiency ◽  
Personal Information ◽  
Support Vector ◽  
Learning Models ◽  
Rule Based ◽  
Common Purpose ◽  
Behavioral Method ◽  
And Control ◽  
Similarity Method

The phenomenon of phishing has now been a common threat, since many individuals and webpages have been observed to be attacked by phishers. The common purpose of phishing activities is to obtain user’s personal information for illegitimate usage. Considering the growing intensity of the issue, this study is aimed at developing a new hybrid rule-based solution by incorporating six different algorithm models that may efficiently detect and control the phishing issue. The study incorporates 37 features extracted from six different methods including the black listed method, lexical and host method, content method, identity method, identity similarity method, visual similarity method, and behavioral method. Furthermore, comparative analysis was undertaken between different machine learning and deep learning models which includes CART (decision trees), SVM (support vector machines), or KNN ( K -nearest neighbors) and deep learning models such as MLP (multilayer perceptron) and CNN (convolutional neural networks). Findings of the study indicated that the method was effective in analysing the URL stress through different viewpoints, leading towards the validity of the model. However, the highest accuracy level was obtained for deep learning with the given values of 97.945 for the CNN model and 93.216 for the MLP model, respectively. The study therefore concludes that the new hybrid solution must be implemented at a practical level to reduce phishing activities, due to its high efficiency and accuracy.

Corrosion Prevention in Boilers by Using Energy Audit Consideration

2014 ◽  
Vol 532 ◽  
pp. 307-310 ◽  
Author(s):  
Mokhtari Karchegani Amir ◽  
Maboudi Samad ◽  
Shehni Meidani Behzad ◽  
Satari Manesh Mehdi
Keyword(s):  
High Efficiency ◽  
Process Condition ◽  
Polluted Environment ◽  
Energy Audit ◽  
Corrosion Prevention ◽  
Control Loops ◽  
Excess Air ◽  
Short Period ◽  
Boiler Tubes ◽  
Low Efficiency

Marun's petrochemical boilers after four years was auditing by a team consist of different experts. Result of that audit was showing over design consuming of excess air and fuel which it cause low efficiency of working that evaluated by a program in excel application. For next step by using Fluent &Gambit software, boiler analyzed and it appeared that some of primary rows of boiler bank tubes caused overheating and after report, because of exceed requirement of steam for operation, boilers operated without stopping. So after short period some of boiler tubes ruptured and this failure continued until were decided to repair and replace overheated tubes with new ones and by calibrated and changed instrument logic, correction control loops, excess air set and it caused better efficiency, decrease polluted environment gas, prevention of corrosion in tubes, decrease fuel consumption and turning off one of boilers by receiving high efficiency of others boiler. So by using designed excel program for boiler process, condition monitoring perform monthly.

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