scholarly journals Investigations on disposal of low-calorific landfill gases by a small scale fluidised bubbling bed combustion plant

2013 ◽  
Vol 9 (1) ◽  
pp. 42-50
Keyword(s):  
Gas Flow ◽  
Landfill Gas ◽  
Pollutant Emission ◽  
Small Scale ◽  
Fluidised Bed ◽  
Load Range ◽  
Combustion Gas ◽  
Operation Conditions ◽  
Bubbling Bed ◽  
Landfill Gases

Poor landfill gases cannot be used to drive gas engines or be burnt in gas flares. This follows why the combustion flame front velocity for poor gases becomes very low. From this moment the non-flammable poor landfill gases are polluting the environment. An energetical utilisation of very poor landfill gases is of ecological interest and is also an important contribution for climate protection. A feasible solution must be found. In our University lab we are using a Fluidised Bubbling Bed Combustion (SFBC) plant with 200 kW completed by heat exchangers for pre-heating the combustion air as well the combustion gas. In the past this SFBC-principle had successfully been applied to a thermal utilization of very different wastes. Using this principle we are able to recover the energy content of very poor landfill gases down to a concentration below the lower explosion limit. The fluidised red hot inertia bed material at a temperature of 850°C is an excellent ignition source to run the process at constant parameters within legal limits. Therefore we have very low pollutant emission levels. Using a developed mathematical SFBC-model we theoretically investigated the lowest possibly methane concentration limits under given pre-conditions as well as fluidised bed temperature level, fluidisation air and fuel gas temperatures, necessary oxygen concentration level. Following to these model investigations we realized their experi-mental verification in our 200 kW lab SFBC testing plant in a wide-spread plant load range. These lab tests had very successful results. The possible SFBC operation conditions have been estimated. Based on these results we engineered by the help of industrial partners a real SFBC plant installed on a closed landfill in Mecklenburg – Western Pomerania, 65 km far from our University lab. Using these plant we dispose there real very poor landfill gas. The landfill gas is poor enough to avoid a further operation of a common gas flare. The automatically operated SFBC process is running at 850 °C without any technical interruptions since one year. At the moment the maintenance rate is 3 weeks. The plant is supervised by data remote control. The contribution will compare the lab test results with the results of the real existing plant. If the poor landfill gas flow is strong enough the SFBC produces enough energy e.g. to drive a steam cycle or a gas turbine externally fired by the SFBC that generates electrical power. In this case the necessary power equipment has to be added to the SFBC plant.

FBC: Laboratory Scale Research to Small Scale Practical Operation

2005 ◽  
Author(s):  
E. M. Bulewicz ◽  
S. Kandefer ◽  
M. Pilawska ◽  
W. Z˙ukowski ◽  
J. Baron
Keyword(s):  
Coal Combustion ◽  
Laboratory Scale ◽  
Small Scale ◽  
Laboratory System ◽  
Fluidised Bed ◽  
Physicochemical Processes ◽  
Bubbling Bed ◽  
Practical Operation ◽  
Visual Phenomena ◽  
Combustible Gases

Working with a small, bubbling laboratory scale fluidised bed combustor for many years, helped to gain some insights into the fundamental physicochemical processes taking place in fluidised bed combustors in general, irrespective of size. For example, it has been demonstrated that during coal combustion as a rule the gases leaving the bed cannot be assumed to be at full thermal equilibrium and that when gases are burned the associated acoustic and visual phenomena can be explained in terms of bubbles of the combustible gases exploding within the bed. Much of the experience gained in running the laboratory system has been used in small scale practice, in designing and controlling small, but successful fluidised bed combustors up to about 3 MW. Several 1MW units have now been in operation for over 10 years. It has also been demonstrated that small bubbling bed combustors can be used for disposing of certain biomass and other wastes.

scholarly journals 3–D Models of Galaxy Magnetic Fields with Spiral Shocks

1990 ◽  
Vol 140 ◽  
pp. 133-134
Author(s):  
J. Panesar ◽  
A.H. Nelson
Keyword(s):  
Gas Flow ◽  
Density Wave ◽  
Shock Velocity ◽  
Small Scale ◽  
Hydrodynamic Simulation ◽  
Dynamo Equation ◽  
Scale Turbulence ◽  
Wave Induced ◽  
The Magnetic Field ◽  
Stellar Density

We report here some preliminary results of 3–D numerical simulations of an α–ω dynamo in galaxies with differential rotation, small–scale turbulence, and a shock wave induced by a stellar density wave. We obtain the magnetic field from the standard dynamo equation, but include the spiral shock velocity field from a hydrodynamic simulation of the gas flow in a gravitational field with a spiral perturbation (Johns and Nelson, 1986).

Numerical Study of Methane and Air Combustion Inside Heat-Recirculating Combustors

2013 ◽  
Author(s):  
Yanxia Li ◽  
Zhongliang Liu ◽  
Yan Wang ◽  
Jiaming Liu
Keyword(s):  
Gas Flow ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Central Area ◽  
Small Scale ◽  
Inlet Velocity ◽  
Strong Convection ◽  
Simulation Results ◽  
Lean Fuel ◽  
Set Up

A numerical model on methane/air combustion inside a small Swiss-roll combustor was set up to investigate the flame position of small-scale combustion. The simulation results show that the combustion flame could be maintained in the central area of the combustor only when the speed and equivalence ratio are all within a narrow and specific range. For high inlet velocity, the combustion could be sustained stably even with a very lean fuel and the flame always stayed at the first corner of reactant channel because of the strong convection heat transfer and preheating. For low inlet velocity, small amounts of fuel could combust stably in the central area of the combustor, because heat was appropriately transferred from the gas to the inlet mixture. Whereas, for the low premixed gas flow, only in certain conditions (Φ = 0.8 ～ 1.2 when ν0 = 1.0m/s, Φ = 1.0 when ν0 = 0.5m/s) the small-scale combustion could be maintained.

High Temperature Stability of MGCs Gas Turbine Components in Air and Combustion Gas Flow Environments

2004 ◽  
Author(s):  
Narihito Nakagawa ◽  
Hideki Ohtsubo ◽  
Kohji Shibata ◽  
Atsuyuki Mitani ◽  
Kazutoshi Shimizu ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Gas Flow ◽  
Temperature Stability ◽  
High Temperature Strength ◽  
High Temperature Stability ◽  
Combustion Gas ◽  
Air Atmosphere ◽  
Low Nox Emission ◽  
Very High

Melt growth composites (MGCs) have a unique microstructure, in which continuous networks of single-crystal phases interpenetrate without grain boundaries. Therefore, the MGCs have excellent high-temperature strength characteristics, creep resistance, oxidation resistance and thermal stability in an air atmosphere at very high temperature. To achieve ultra-high thermal efficiency and low NOx emission for gas turbine systems, non-cooled turbine nozzle vanes and heat shield panels of combustor liners has been fabricated on an experimental basis. These components are thermally stable after heat treatment at 1700°C for 1000 hours in an air atmosphere. In addition, we have just started the exposure tests to evaluate the influence of combustion gas flow environment on MGCs.

scholarly journals Studi Penggunaan Variable Speed Drive Untuk Pengaturan Kecepatan Motor Exhaust Fan Pada Dyno Test Room PT. Trakindo Utama Pekanbaru

JURNAL TEKNIK ◽  
2018 ◽  
Vol 12 (2) ◽  
pp. 85-96
Author(s):  
Elham Prasetyo Wibowo ◽  
Elvira Zondra ◽  
Usaha Situmeang
Keyword(s):  
Power Consumption ◽  
Induction Motor ◽  
Gas Flow ◽  
Air Flow ◽  
Load Test ◽  
Exhaust Gas ◽  
Variable Speed ◽  
Variable Speed Drive ◽  
Combustion Gas ◽  
Motor Exhaust

                                                                                                                                      ABSTRAK              Exhaust fan adalah peralatan berupa sudu-sudu yang berputar dan memanfaatkan gaya sentrifugal untuk membuang exhaust gas hasil pembakaran bahan bakar solar engine diesel pada saat dilakukan tes pembebanan penuh. Dengan exhaust fan, gas karbondioksida yang dihasilkan oleh engine diesel memungkinkan untuk dibuang dengan cepat sehingga tidak memenuhi ruangan dan membahayakan bagi setiap karyawan. Pengoperasian exhaust fan dilakukan sesuai jadwal pengetesan engine. Exhaust fan tersebut digerakkan oleh motor induksi 3 phasa 30 kW dengan putaran nominal secara konstan. Pada saat pengetesan engine dengan nilai aliran gas buang yang rendah, exhaust fan tetap dioperasikan dengan kecepatan nominal. Operasional motor exhaust fan dengan kecepatan konstan seperti ini akan mengakibatkan konsumsi daya listrik yang relatif tinggi dari pada motor dengan kecepatan berubah-ubah sesuai kebutuhan. Sebagai pertimbangan hasil perhitungan untuk engine C 18 Caterpillar kapasitas 831 hp yang sebelumya  membutuhkan operasional exhaust fan dengan daya 24,7927 kW nilai sama untuk semua model engine, setelah penggunaan VSD dapat dikurangi sebesar 14,35 %  menjadi 21,2343 kW saja. Penelitian ini bertujuan mendapatkan probabilitas hubungan antara konsumsi energi listrik, frekuensi pada variable speed drive, putaran motor induksi dan nilai aliran udara pada cerobong exhaust fan. Nilai aliran udara exhaust fan tersebut akan disesuaikan dengan nilai aliran gas pembakaran yang dihasilkan oleh engine. Analisa optimasi motor exhaust fan ini sedianya akan menggunakan Matematic Analysis dan simulasi menggunakan simulink matlab sehingga diharapkan ada solusi untuk melakukan penghematan terhadap konsumsi daya motor, kemudian bisa diterapkan dalam semua pengoperasian motor yang ada di perusahaan.   Kata kunci : variable speed drive, motor induksi, exhaust fan                                                                                                                                            ABSTRACT              The exhaust fan is a rotary blade device which produces centrifugal force to remove exhaust gas from diesel fuel combustion during a full load test. With exhaust fans, the carbondioxide gases that generated by the diesel engine allows to be disposed quickly so that it does not fill the room and harm to every employee. The operation of  exhaust fan is carried out according to the engine test schedule. The exhaust fan is driven by a 3 phase induction motor of  30 kW with constant rotation. When testing the engine with a low Exhaust Gas flow value, the exhaust fan remains operated at rated speed. Operational exhaust fan with a constant speed like this will result in relatively high power consumption of the motor with the speed of change as needed. Considering the calculation results for C 18 engine Caterpillar capacity of 831 hp which previously required operational exhaust fan with 24,7927 kW of equal value for all engine models, after the use of VSD can be reduced by 14.35% to 21.2343 kW only. This study aims to obtain the probability of relationship between electrical energy consumption, frequency on the variable speed drive, induction motor rotation and the value of air flow in the exhaust fan chimney. The value of the exhaust fan air flow will be adjusted to the combustion gas flow value generated by the engine. The optimization analysis of this motor exhaust fan will be using Matematic Analysis and simulation using matlab simulink so it is expected there is a solution to make savings to motor power consumption, then it can be applied in all the motor operation in the company.   Keywords: variable speed drive, induction motor, exhaust fan

Development and Validation of a Design Tool for an Improved Pitot-Tube Jet-Pump Allowing Continuous Fluid-Fluid Separation

2021 ◽  
Author(s):  
Jan Deylen ◽  
Jessica Köpplin ◽  
Dominique Thevenin
Keyword(s):  
Oil Spills ◽  
Separation Efficiency ◽  
Scale Up ◽  
Design Tool ◽  
Pitot Tube ◽  
Polluted Water ◽  
Small Scale ◽  
Water Mixture ◽  
Jet Pump ◽  
Operation Conditions

Abstract A Pitot-tube Jet-Pump (PTJ pump) has been considerably modified and extended in order to continuously separate and transport liquids of different densities. As a first application, an oil-water mixture is considered in this work. The modified PTJ pump could be used as a primary separator for oil-polluted water (e.g., around off-shore platforms, after oil spills from ships), while additionally being able to transport the resulting fluid to further heaters, exchangers, centrifuges, distillation columns, etc., without necessitating additional machinery. The performance behavior of the separating PTJ pump (abbreviated SPP in what follows) has been first investigated with computational fluid dynamics (CFD), and then validated by comparison with experimental data acquired on a small-scale prototype. Based on these observations, a design tool has been developed to (i) predict performance and (ii) support proper device scaling. This tool is based on dimensionless parameters that are already employed for classical turbomachinery, similar to the Cordier chart. However, since the SPP works at an extremely low specific speed, its operating points lie outside the standard Cordier chart. To verify the accuracy of the design tool, a scale-up test has been conducted and validated by CFD, delivering a good agreement. A separation efficiency better than 99% has been obtained in the experiments for suitable operation conditions, while the numerical scale-up test reveals a head of 15.1 m and an oil content below 0.2% in the purified water at the High-Pressure Outlet.

scholarly journals Numerical Analysis on Effect of Additional Gas Injection on Characteristics around Raceway in Melter Gasifier

2019 ◽  
Vol 38 (2019) ◽  
pp. 837-848
Author(s):  
Du Kaiping ◽  
Gao Xiangzhou ◽  
Sun Haibo
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Gas Injection ◽  
Coke Oven ◽  
Pure Oxygen ◽  
Small Scale ◽  
Gas Temperature ◽  
Fuel Gas ◽  
Hot Air ◽  
Flow Circulation

AbstractThe raceway plays an important role in the mass and heat transportation inside a melter gasifier. Considering that pure oxygen at room temperature instead of hot air is injected into the melter gasifier, a two-dimensional mathematical model at steady state is developed in the current work to describe the effect of the additional gas injection on the characteristics around the raceway in melter gasifier. The results show that a high-speed jet with a highest temperature above 3500 K could be found in front of tuyere. Furthermore, a small scale of gas flow circulation occurs in front of tuyere that results in a more serious thermal damage to tuyere. In order to decrease the gas temperature in the raceway to prevent the blowing-down caused by tuyere damage, the additional gas, including N2, natural gas (NG) and coke oven gas (COG) should be injected through the tuyere. Compared with N2, additional fuel gas injection gives full play to the high temperature reduction advantage of hydrogen. In addition, considering the insufficient hearth heat after injecting NG and the effective utilization of secondary resource, an appropriate amount of COG is recommended to be injected for optimizing blast system.

scholarly journals The Thermo-Aerodynamical Analysis of Combustion Gas Flow (1st Report)

1959 ◽  
Vol 2 (5) ◽  
pp. 138-143
Author(s):  
Sugao SUGAWARA ◽  
Itaru MICHIYOSHI
Keyword(s):  
Gas Flow ◽  
Combustion Gas

Exposure Test Results of Lu2Si2O7 in Combustion Gas Flow at High Temperature and High Speed

2004 ◽  
Author(s):  
Isao Yuri ◽  
Tohru Hisamatsu ◽  
Shunkichi Ueno ◽  
Tatsuki Ohji
Keyword(s):  
Weight Loss ◽  
Water Vapor ◽  
Partial Pressure ◽  
Gas Flow ◽  
Loss Rate ◽  
Gas Temperature ◽  
Weight Loss Rate ◽  
Combustion Gas ◽  
Vapor Partial Pressure ◽  
Water Vapor Partial Pressure

In order to understand recession behavior and the amount of recession of Lu2Si2O7 in the combustion gas flow, sintered Lu2Si2O7 specimens were manufactured by hot pressing and exposed under various combustion gas flow conditions (T = 1300–1500 °C, P = 0.3 MPa, V = 150 m/s, PH2O = 27–69 kPa, t = 10h). After the exposure tests, etch pits, which are assumed to form due to volatilization of SiO2 in the grain boundary phase, were observed at the surface of specimen. The amount of Lu2SiO5 phase at the surface of specimen increased with the increase of gas temperature or water vapor partial pressure. A corresponding decrease in the amount of Lu2Si2O7 phase was observed. Furthermore, by using the average weight loss rate for exposure times of ten hours, the influence of gas temperature and water vapor partial pressure on weight loss rate was examined, and the amount of recession under gas turbine conditions was calculated.

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