The Effects of Air Flow Rates, Secondary Air Inlet Geometry, Fuel Type, and Operating Mode on the Performance of Gasifier Cookstoves

2016 ◽  
Vol 50 (17) ◽  
pp. 9754-9763 ◽  
Author(s):  
Jessica Tryner ◽  
James W. Tillotson ◽  
Marc E. Baumgardner ◽  
Jeffrey T. Mohr ◽  
Morgan W. DeFoort ◽  
...  
Keyword(s):  
Air Flow ◽  
Operating Mode ◽  
Fuel Type ◽  
Flow Rates ◽  
Air Inlet ◽  
Inlet Geometry ◽  
Secondary Air

Model-Based Analysis of Transient Behavior of Large Scale CFB Boilers

2003 ◽  
Author(s):  
Ari Kettunen ◽  
Timo Hyppa¨nen ◽  
Ari-Pekka Kirkinen ◽  
Esa Maikkola
Keyword(s):  
Flow Rate ◽  
Large Scale ◽  
Air Flow ◽  
Model Parameters ◽  
Air Flow Rate ◽  
Process Data ◽  
Cfb Boiler ◽  
Flow Rates ◽  
Load Change ◽  
Secondary Air

The main objective of this study was to investigate the load change capability and effect of the individual control variables, such as fuel, primary air and secondary air flow rates, on the dynamics of large-scale CFB boilers. The dynamics of the CFB process were examined by dynamic process tests and by simulation studies. A multi-faceted set of transient process tests were performed at a commercial 235 MWe CFB unit. Fuel reactivity and interaction between gas flow rates, solid concentration profiles and heat transfer were studied by step changes of the following controllable variables: fuel feed rate, primary air flow rate, secondary air flow rate and primary to secondary air flow ratio. Load change performance was tested using two different types of tests: open and closed loop load changes. A tailored dynamic simulator for the CFB boiler was built and fine-tuned by determining the model parameters and by validating the models of each process component against measured process data of the transient test program. The know-how about the boiler dynamics obtained from the model analysis and the developed CFB simulator were utilized in designing the control systems of three new 262 MWe CFB units, which are now under construction. Further, the simulator was applied for the control system development and transient analysis of the supercritical OTU CFB boiler.

Calculation of the Parameters of Combustion Products of Sewage Sludge

2018 ◽  
Vol 22 (6) ◽  
pp. 54-57
Author(s):  
A.V. Demin ◽  
R.Ya. Dyganova ◽  
V.P. Shipkov ◽  
R.R. Valiev
Keyword(s):  
Sewage Sludge ◽  
Phase Equilibria ◽  
Air Flow ◽  
Combustion Products ◽  
Flow Rates ◽  
Optimal Ratio ◽  
Secondary Air

The problems associated with the use of existing thermal installations for the incineration of sewage sludge and the design of new structures are considered. The results obtained by calculating the chemical and phase equilibria are presented. Recommended optimal ratio of primary and secondary air flow rates with its step-by-step approach.

Experiments on Aft-Disk Cavity Ingestion in a Model 1.5-Stage Axial-Flow Turbine

2011 ◽  
Author(s):  
J. Balasubramanian ◽  
N. Junnarkar ◽  
D. W. Zhou ◽  
R. P. Roy ◽  
Y. W. Kim ◽  
...  
Keyword(s):  
Velocity Field ◽  
Fluid Velocity ◽  
Air Flow ◽  
Axial Flow ◽  
Initial Step ◽  
Labyrinth Seal ◽  
Radial Clearance ◽  
Main Stream ◽  
Flow Rates ◽  
Secondary Air

Experiments were carried out in a model 1.5-stage (vane-blade-vane) axial-flow air turbine to investigate the ingestion of main-stream air into the aft disk cavity. This cavity features rotor and stator rim seals with radial clearance and axial overlap, and an inner labyrinth seal. Results are reported for two main air flow rates, two rotor speeds, and three purge (secondary) air flow rates. The initial step at each experimental condition was the measurement of time-average static pressure distribution in the turbine stage to ensure that a nominally steady run condition had been achieved. Subsequently, tracer gas concentration and particle image velocimetry (PIV) techniques were employed to measure, respectively, the main gas ingestion into the disk cavity (rim and inner parts) and the fluid velocity field in the rim cavity. Finally, the egress trajectory of the purge air into the main-stream air was mapped in the axial-radial plane by PIV at multiple circumferential positions within one aft vane pitch. The purge air egress trajectory and velocity field are important because the interaction of this air with the main gas stream has aerodynamic, stage performance, and downstream vane/endwall heat transfer implications.

Nitrogen Removal from Anaerobically-Treated Leachate

1984 ◽  
Vol 19 (1) ◽  
pp. 87-100
Author(s):  
D. Prasad ◽  
J.G. Henry ◽  
P. Elefsiniotis
Keyword(s):  
Nitrogen Removal ◽  
Air Flow ◽  
Operating Conditions ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Anaerobic Filter ◽  
Ph Values ◽  
Wide Range ◽  
Ammonia Desorption ◽  
Effects Of Ph

Abstract Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L. Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

149 Evaluation of Hammermill Tip Speed, Air Assist, and Screen Hole Diameter on Ground Corn Characteristics

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 134-135
Author(s):  
Michaela B Braun ◽  
Kara M Dunmire ◽  
Michael Sodak ◽  
Jerry Shepherd ◽  
Randy Fisher ◽  
...  
Keyword(s):  
Particle Size ◽  
Geometric Mean ◽  
Air Flow ◽  
Hole Diameter ◽  
Experimental Unit ◽  
Flow Index ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Composite Flow ◽  
Ground Corn

Abstract This study was performed to evaluate hammermill tip speed, assistive airflow and screen hole diameter on hammermill throughput and characteristics of ground corn. Corn was ground using two Andritz hammermills (Model: 4330–6, Andritz Feed & Biofuel, Muncy,PA) measuring 1-m in diameter each equipped with 72 hammers and 300 HP motors. Treatments were arranged in a 3 × 3 × 3 factorial design with 3 tip speeds (3,774, 4,975, and 6,176 m/min), 3 screen hole diameters (2.3, 3.9 and 6.3 mm), and 3 air flow rates (1,062, 1,416, and 1,770 fan RPM). Corn was ground on 3 separate days to create 3 replications and treatments were randomized within day. Samples were collected and analyzed for moisture, particle size, and flowability characteristics. Data were analyzed using the GLIMMIX procedure of SAS 9.4 with grinding run serving as the experimental unit and day serving as the block. There was a 3-way interaction for standard deviation (Sgw), (linear screen hole diameter × linear hammer tip speed × linear air flow, P = 0.029). There was a screen hole diameter × hammer tip speed interaction (P < 0.001) for geometric mean particle size dgw (P < 0.001) and composite flow index (CFI) (P < 0.001). When tip speed increased from 3,774 to 6,176 m/min the rate of decrease in dgw was greater as screen hole diameter increased from 2.3 to 6.3 mm resulting in a 67, 111, and 254 µm decrease in dgw for corn ground using the 2.3, 3.9, and 6.3 mm screen hole diameter, respectively. For CFI, increasing tip speed decreased the CFI of ground corn when ground using the 3.9 and 6.3 mm screen. However, when grinding corn using the 2.3 mm screen, there was no evidence of difference in CFI when increasing tip speed. In conclusion, the air flow rate did not influence dgw of corn but hammer tip speed and screen size were altered and achieved a range of dgw from 304 to 617 µm.

Evaluation of pressure coefficients and estimation of air flow rates in buildings employing wind towers

Solar Energy ◽  
1986 ◽  
Vol 37 (5) ◽  
pp. 363-374 ◽  
Author(s):  
C. Karakatsanis ◽  
M.N. Bahadori ◽  
B.J. Vickery
Keyword(s):  
Air Flow ◽  
Flow Rates ◽  
Pressure Coefficients

Membrane air flow rates and HF sludging phenomenon in SMBR

Desalination ◽  
2009 ◽  
Vol 236 (1-3) ◽  
pp. 135-142 ◽  
Author(s):  
Julie Lebegue ◽  
M. Heran ◽  
A. Grasmick
Keyword(s):  
Air Flow ◽  
Flow Rates

scholarly journals Test of Fast Pyrolysis at Bed Reactor Fluidized with Three Air Flow Rates

2013 ◽  
Vol 21 (1) ◽  
pp. 31-38
Author(s):  
R.A. Jordan ◽  
L.A.B. Cortez ◽  
R. Baldassin Júnior ◽  
J.M.M. Perez
Keyword(s):  
Air Flow ◽  
Fast Pyrolysis ◽  
Flow Rates
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