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.

STUDI EFISIENSI BOILER TERHADAP NILAI KALOR BATUBARA PADA BOILER JENIS PULVERIZER COAL KAPASITAS 300 T/H

2020 ◽  
Vol 3 (2) ◽  
pp. 122-130
Author(s):  
Wawan Gunawan ◽  
Bambang Ali Gunawan
Keyword(s):  
Flue Gas ◽  
Turbine Generator ◽  
Fuel Ratio ◽  
Excess Air ◽  
Heat Value

Boiler merupakan proses terjadinya pembakaran bahan bakar batubara pada bejana tertutup yang digunakan untuk menghasilkan steam. Steam tersebut dapat menggerakkan turbine-generator untuk menghasilkan listrik. Excess air merupakan persentase oksigen didalam fraksi massa yang terkandung didalam udara hasil pembakaran (flue gas). Nilai excess air dan efisiensi pada mesin boiler dapat diketahui dengan metode analisa deskriptif dan analisa perhitungan. Tujuan penelitian ini adalah untuk mengetahui pengaruh nilai kalor batubara terhadap nilai efisiensi dan pengaruh nilai kalor batubara terhadap excess air dengan menggunakan metode analisa deskriptif. Prosedur perhitungan diawali dengan menghitung entalpi aktual, low heat value, efisiensi aktual pada variasi nilai kalor batubara dan menghitung Air Fuel Ratio (AFR) aktual, Air Fuel Ratio (AFR) ideal, serta excess air pada mesin boiler. Hasil perhitungan menunjukkan penggunaan batubara dengan nilai LHV lebih besar menghasilkan nilai efisiensi boiler yang lebih tinggi. Penggunaan batubara dengan LHV 31.773 kJ/kg memberikan nilai efisiensi boiler mencapai 57 % dengan nilai excess air sebesar 63,6 %. Sehingga nilai kalor batubara yang lebih tinggi memerlukan excess air yang lebih rendah serta menghasilkan efisiensi yang lebih tinggi.

The Partition Period of Thermodynamic Calculation and the Numerical Simulation for Lignite Blended Supercritical Boiler

2014 ◽  
Vol 1030-1032 ◽  
pp. 648-652
Author(s):  
Cai Ying Ban ◽  
Xu Ao Lu ◽  
Jian Meng Yang ◽  
Xu Ran ◽  
Feng Ying Liang
Keyword(s):  
Numerical Simulation ◽  
Flue Gas ◽  
Thermodynamic Calculation ◽  
Heat Load ◽  
Combustion Process ◽  
Heating Surface ◽  
Gas Temperature ◽  
Boiler Furnace ◽  
Geometry Model ◽  
The Impact

The purpose of this paper is to study the impact of furnace temperature and load after blending in lignite, based on CFD software FLUENT-6.3,this paper choose the appropriate geometry model and the physical and mathematical models, and numerical simulation of the different conditions 600MW supercritical once-through boiler blending lignite furnace combustion process is curried out. And through a 600MW supercritical coal-fired boiler furnace lignite blended performed sections thermodynamic calculation under different conditions, worked out the furnace flue gas temperature, CO, CO2concentration distribute trend and radiant heat each section surface heat load conditions. The specific amount were blended with 5%, 10%, 15%, 20% were not dried lignite and dried lignite 20% after five conditions. And obtained a conclusion is the temperature and radiation heating surface flue gas heat load in the overall trend under the various conditions.

scholarly journals Numerical investigation of lambda-value prechamber ignition in heavy duty natural gas engine

2020 ◽  
Vol 181 (2) ◽  
pp. 31-39
Author(s):  
Ireneusz PIELECHA
Keyword(s):  
Natural Gas ◽  
Stoichiometric Composition ◽  
Combustion Process ◽  
Strong Relationship ◽  
Heavy Duty ◽  
Excess Air ◽  
Excess Air Coefficient ◽  
Lean Mixtures ◽  
A Charge ◽  
The Impact

Turbulent Jet Ignition systems are mainly dedicated to the combustion of lean mixtures of natural gas in heavy duty engines. The use of such a system in combination with lean mixtures leads to an increase in its overall efficiency. The article presents simulation analyzes of the impact of the excess air coefficient occurring in prechamber on the combustion process: combustion indicators and emission indicators. Tests on a single-cylinder engine with a displacement of about 4 dm3 at medium mixture (IMEP = 1.0 MPa) were carried out using the AVL Fire software. It was found that the incineration of global lean mixtures (lambda = 2) is effective when initiating this process (in the prechamber) with a charge of a stoichiometric composition. A strong relationship was found between the thermodynamic indicators in both prechamber and main chamber and the excess air coefficient initiating combustion.

scholarly journals AIR SUPPLY REGULATOR FOR THE WORKING SPACE HEAT INSTALLATION BASED ON FUZZY LOGIC

2020 ◽  
pp. 99-121
Author(s):  
Mikhail Vasil'ev ◽  
◽  
Sergei Andreev ◽  
Ivan Vasil'ev ◽  
◽  
...  
Keyword(s):  
Natural Gas ◽  
Fuzzy Control ◽  
Energy Saving ◽  
Fuel Consumption ◽  
Flue Gas ◽  
Air Flow ◽  
Combustion Process ◽  
Control Mode ◽  
Working Space ◽  
Excess Air

The combustion process in the working space of a heat installation is simulated. The static characteristic of the dependence of fuel consumption on air consumption in the conditions of stabilization of heat generated as a result of the combustion process is shown, therefore, the possibility of optimizing this process is proved. A block diagram, mathematical model and algorithm for calculating energy-saving fuzzy control of the combustion process in the working space of a thermal installation are developed. Combustion Membership functions of fuzzy sets for input linguistic variables are compiled. The rule bases are formulated taking into account the static characteristics of the control object. Examples of technological and linguistic justification of fuzzy controller rules are given. The dynamics of changing the controlled parameter is determined by solving two differential equations. The search for levels of "cut-offs" for the prerequisites of each of the rules using the "minimum" operation in accordance with the compiled database of rules is performed. The defuzzification procedure was performed (bringing it to clarity). The advantages of this system over traditional stabilizing control systems under the action of a set of random factors and a significantly nonlinear relationship between input and output values are shown. Optimal values of scaling factors for the developed automatic control system are determined. Let's consider an example of the formation of a control effect when implementing fuzzy energy-saving control of the combustion process in the working space of the boiler unit No. 3 of the GKP-1A UGPU of Gazprom dobycha Urengoy LLC. The calculations of the amount of inleakage of atmospheric air, excess air flow, the sectional area of the pipe supplying air, the total air flow in the working space of the thermal installation, the volume of natural gas participating in the combustion process, heat resulting from the combustion, the amount of air that did not participate in the combustion process, the amount of heat required to increase the temperature of excess air until the average temperature of the flue gas remaining heat of the combustion reaction, changes in the oxygen concentration in the exhaust flue gases depending on the air flow to the burner. The functional dependence of the flue gas temperature on the natural gas consumption is constructed by approximating the initial data of the regime map of the steam boiler. The dynamic properties of an inertia-delayed controlled process are taken into account when using the Euler method. The combustion control mode influence on the specific fuel consumption is estimated. The effects of using a system with fuzzy control in terms of saving natural gas and electricity over the entire range of performance of a thermal installation are estimated.

scholarly journals Numerical Simulation of the Effect of Combustion Process on Flue Gas Thermal Deviation in 660MW Boiler

2020 ◽  
Vol 603 ◽  
pp. 012050
Author(s):  
Xianbiao Yang ◽  
Yuan Gao ◽  
Shutao Wang ◽  
Renqiang Shi ◽  
Shaohua Liang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flue Gas ◽  
Combustion Process ◽  
Thermal Deviation

Investigating the effect of flue gas temperature and excess air coefficient on the size distribution of condensable particulate matters

Fuel ◽  
2021 ◽  
Vol 298 ◽  
pp. 120866
Author(s):  
Yue Peng ◽  
Nan Shi ◽  
Tao Wang ◽  
Jiawei Wang ◽  
Yongsheng Zhang ◽  
...  
Keyword(s):  
Size Distribution ◽  
Flue Gas ◽  
Particulate Matters ◽  
Gas Temperature ◽  
Excess Air ◽  
Excess Air Coefficient

Computer Simulation about Influence of Flue Gas Recycle and Subsection Air on Nitrogen Oxide Formation to Chain Boiler

2010 ◽  
Vol 171-172 ◽  
pp. 702-705
Author(s):  
Jing Han ◽  
Man Yin Hu ◽  
Xiu Hong Wang
Keyword(s):  
Numerical Simulation ◽  
Computer Simulation ◽  
Nitrogen Oxide ◽  
Flue Gas ◽  
Combustion Process ◽  
Nox Emission ◽  
Process Temperature ◽  
Oxide Formation ◽  
A Chain

Numerical simulation is used to study the combustion process，temperature distridution and NOx emission for a 10t/h chain boiler with and without flue gas recycle. And at the same time,it is constrasted that differences when flue gas is recycled to the primary wind inlet and to secondry wind inlet.The results show the temperature distridution decreased with flue gas recycle,so there is less NOx emission.And when flue gas is recycled to secondry wind inlet ,the NOx emission dropped mostly. The result offer a reference to design and operate a chain boiler.

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.

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