scholarly journals Analisa Efisiensi Termal Water Tube Boiler Berdasarkan Rasio Udara Bahan Bakar LPG Untuk Memproduksi Saturated dan Superheated Steam

2021 ◽  
Vol 1 (10) ◽  
pp. 415-421
Author(s):  
Ayuni Lestari ◽  
Valencia Tara Situmorang ◽  
Tahdid Tahdid ◽  
K.A Ridwan ◽  
Agus Manggala
Keyword(s):  
Superheated Steam ◽  
Flame Temperature ◽  
Fuel Ratio ◽  
Water Tube ◽  
Excess Air

Boiler adalah suatu bejana tertutup yang terbuat dari baja dan digunakan untuk menghasilkan steam. Agar dapat menghasilkan steam diperlukan pembakaran. Pembakaran merupakan reaksi eksotermis yang berlangsung sangat cepat, yang membebaskan energi berupa panas dan nyala api (flame temperature) serta mampu menyebarkan panas melalui suatu medium. Agar pembakaran terjadi dengan optimal maka harus memperhatikan nilai rasio udara bahan bakar atau Air Fuel Ratio (AFR). Tujuan dari penelitian ini untuk meningkatkan efisiensi termal water tube boiler. Bahan bakar yang digunakan adalah gas LPG. Oleh karena itu, pada penelitian kali ini akan difokuskan untuk menentukan rasio udara dengan bahan bakar gas yang paling tepat sehingga didapatkan hasil pembakaran dan produksi steam yang maksimal. Rasio udara bahan bakar gas dan excess air yang digunakan yakni, 15,78 (5%), 15,93 (6%), 16,08 (7%), 16,23 (8%), 16,38 (9%).

Analysis of Water–Fuel Ratio Variation in a Gas Turbine With a Wet-Compressor System by Change in Fuel Composition

2017 ◽  
Vol 140 (5) ◽  
Author(s):  
Yonatan Cadavid ◽  
Andres Amell ◽  
Juan Alzate ◽  
Gerjan Bermejo ◽  
Gustavo A. Ebratt
Keyword(s):  
Gas Turbine ◽  
Burning Velocity ◽  
Thermal Power ◽  
Flame Temperature ◽  
Fuel Composition ◽  
Nox Formation ◽  
Gaseous Hydrocarbon ◽  
Power Generators ◽  
Fuel Ratio ◽  
Combustion Properties

The wet compressor (WC) has become a reliable way to reduce gas emissions and increase gas turbine efficiency. However, fuel source diversification in the short and medium terms presents a challenge for gas turbine operators to know how the WC will respond to changes in fuel composition. For this study, we assessed the operational data of two thermal power generators, with outputs of 610 MW and 300 MW, in Colombia. The purpose was to determine the maximum amount of water that can be added into a gas turbine with a WC system, as well as how the NOx/CO emissions vary due to changes in fuel composition. The combustion properties of different gaseous hydrocarbon mixtures at wet conditions did not vary significantly from each other—except for the laminar burning velocity. It was found that the fuel/air equivalence ratio in the turbine reduced with lower CH4 content in the fuel. Less water can be added to the turbine with leaner combustion; the water/fuel ratio was decreased over the range of 1.4–0.4 for the studied case. The limit is mainly due to a reduction in flame temperature and major risk of lean blowout (LBO) or dynamic instabilities. A hybrid reaction mechanism was created from GRI-MECH 3.0 and NGIII to model hydrocarbons up to C5 with NOx formation. The model was validated with experimental results published previously in literature. Finally, the effect of atmospheric water in the premixed combustion was analyzed and explained.

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.

scholarly journals Optimal control of a double-barbane water-tube boiler

2021 ◽  
Vol 244 ◽  
pp. 09003
Author(s):  
Andrey Smolyaninov ◽  
Irina Poсebneva ◽  
Kirill Garmonov ◽  
Alexander Bahmetev
Keyword(s):  
Mathematical Modeling ◽  
Optimal Control ◽  
Control System ◽  
Control Algorithm ◽  
Superheated Steam ◽  
Natural Circulation ◽  
Channel One ◽  
Water Tube ◽  
Effective Suppression ◽  
Physical Tests

The article discusses the synthesis of a control system that implements optimal control of a double-drum water-tube boiler with natural circulation with effective suppression of disturbing influences and ensuring astatism of the control channel. One of the main channels of the object is described in the most detail, the channel “fuel consumption - pressure of superheated steam”, which is decoupled from others. Therefore, it is for him that we will carry out the calculation of the automatic control system (ACS), the reaction of the system to a stepwise disturbing effect is indicated. Using the method of mathematical modeling, the operability of the synthesized control system was confirmed, its operability when the parameters of the model were varied twice, which indicates the possibility of transition from model to physical tests of the proposed control algorithm.

Experimental Study on Combustion Characteristic of Biomass Micron Fuel

2017 ◽  
Author(s):  
Qi Zhang ◽  
Bo Xiao ◽  
Shiping Jin ◽  
Xun Wang ◽  
Xiaokang Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Combustion Temperature ◽  
Combustion Characteristic ◽  
Agriculture Waste ◽  
Fuel Feed ◽  
Fuel Ratio ◽  
Excess Air ◽  
Waste Energy ◽  
Excess Air Coefficient ◽  
Forestry Residues

This study developed a new kind of biomass fuel with biomass (forestry residues, agriculture waste, energy crops and so on) crushed below certain particle size (micron level, ≤250 μm) to form biomass powder, biomass-micron-fuel (BMF). And effects of excess air coefficient, air-fuel ratio, and particle size of BMF on the combustion temperature were studied through a self-designed lab-scale cyclone combustion system. Results showed that temperature increased first and then decreased with the increasing air flow rate and best excess air coefficient occurred in the region of 1.05–1.18. Similarly, combustion temperature also increased first and then decreased as the fuel feed rate increased and 225 g/m3–265 g/m3 air-fuel ratio would guarantee the effective combustion of BMF. The influence of particle size on the combustion temperature was also determined under five different combustion conditions and results demonstrated that the smaller the particle size is, the higher the temperature will be. (CSPE)

Adiabatic Flame Temperature and Product Composition for Lean Combustion of Hydrogen-Methane Combination

1994 ◽  
Author(s):  
Zafer Dülger
Keyword(s):  
Equivalence Ratio ◽  
Flame Temperature ◽  
Adiabatic Flame Temperature ◽  
Lean Combustion ◽  
Excess Air ◽  
Co2 Concentrations ◽  
Hydrogen Mixtures ◽  
Lean Limit ◽  
Hydrogen Enrichment ◽  
Combustion Of Hydrogen

Abstract Adiabatic combustion of methane (natural gas)-hydrogen mixtures is analyzed The adiabatic flame temperature and products composition (especially NOx and CO2 concentrations) variation with excess air (fuel-air equivalence ratio), hydrogen enrichment of methane, and reactant temperature is determined It is shown that reductions in NOx and CO2 emissions are possible with the extended lean limit of combustion of methane associated with hydrogen enrichment CO2 concentrations are also reduced with hydrogen enrichment, reductions being dependent upon the degree of enrichment.

scholarly journals Two-Stroke Low Speed Diesel Engine Simulation Model for NOx Analysis

2017 ◽  
Vol 6 (1) ◽  
pp. 14-23
Author(s):  
Branko Lalić ◽  
Nikola Račić ◽  
Gojmir Radica
Keyword(s):  
Diesel Engine ◽  
Simulation Model ◽  
Flame Temperature ◽  
Combustion Process ◽  
Nox Emissions ◽  
Oxide Formation ◽  
Slow Speed ◽  
Engine Simulation ◽  
Excess Air ◽  
Marine Engines

All commercial marine engines have to comply with IMO regulations on emissions, especially of nitrogen oxides. This paper describes the gases produced in the combustion process in the diesel engine, and the manner of pollutant creation. Several models of slow-speed diesel engines have been developed and analysed. The characteristics of the simulation model are compared with the characteristics obtained on the testbed, and their differences considered. Using the term for the formation of NOx, as well as independently developed programs in MATLAB, the rate of nitrogen oxide formation was obtained as a function of excess air, pressure and temperature. The reduction of excess air increases adiabatic flame temperature and has an effect on NOx emissions. The obtained results are compared with the actual values measured on the testbed.

Influence of Excess Air Factor on NOx Emissions From a 200 kW Swirl Burner

2015 ◽  
Author(s):  
Abdallah Ahmed ◽  
Essam E. Khalil ◽  
Hatem Kayed ◽  
Mohamed M. A. Hassan
Keyword(s):  
Combustion Chamber ◽  
Air Temperature ◽  
Gas Turbines ◽  
Flame Temperature ◽  
Combustion Process ◽  
Operating Conditions ◽  
Swirl Burner ◽  
Nox Formation ◽  
Excess Air ◽  
Thermal Nox

NOx formation during the combustion process occurs mainly through the oxidation of nitrogen in the combustion air (thermal NOx) and through oxidation of nitrogen with the fuel (prompt NOx). The present study aims to investigate numerically the problem of NOx pollution using a model of combustion chamber with 200 kW swirl burner utilizing propane as fuel. The importance of this problem is mainly due to its relation to the pollutants produced by boiler furnaces and gas turbines, which used widely in thermal industrial plants. Governing conservation equations of mass, momentum and energy, and equations representing the transport of species concentrations, turbulence, combustion and radiation modeling in addition to NOx modeling equations were solved together to present temperature and OH distribution inside the combustion chamber, and the NOx concentration at the combustion chamber exit, at various operating conditions of fuel to air ratio. In particular, the simulation provided more insight on the correlation between the peak flame temperature and the thermal NOx concentration. The results have shown that the peak flame temperature and NOx concentration decrease as the excess air factor λ increases. When considering a fixed value of mass flow rate of fuel, the results show that increasing λ results in a maximum value of thermal NOx concentration at the exit of the combustion chamber at λ = 1.05. As the combustion air temperature increases, and the thermal NOx concentration increases sharply. However, when λ exceeds this value NOx concentration starts to decrease due to the combustion air temperature decrease.

Experimental study on cycle-to-cycle variations in natural gas/methanol bi-fueled engine under excess air/fuel ratio at 1.6

Energy ◽  
2021 ◽  
Vol 224 ◽  
pp. 120233
Author(s):  
Zhanming Chen ◽  
Jingjing He ◽  
Hao Chen ◽  
Limin Geng ◽  
Peng Zhang
Keyword(s):  
Experimental Study ◽  
Natural Gas ◽  
Fuel Ratio ◽  
Excess Air
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