scholarly journals The Measured Energy Impact of Infiltration in an Outdoor Test Cell

1996 ◽  
Vol 118 (3) ◽  
pp. 162-167 ◽  
Author(s):  
D. E. Claridge ◽  
Mingsheng Liu
Keyword(s):  
Energy Consumption ◽  
Solar Radiation ◽  
Air Flow ◽  
Test Cell ◽  
Air Leakage ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Energy Impact ◽  
Air Infiltration ◽  
Outdoor Test

Air infiltration energy consumption was investigated in an outdoor test cell with different leakage configurations and air flow rates under both infiltration and exfiltration. Measurements showed that under heating conditions, the air infiltration energy consumption ranged from 55 percent less than to 15 percent greater than the classically calculated values, depending on the air flow rate and direction (infiltration or exfiltration), solar radiation, and air leakage configuration.

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.

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.

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.

Coordinated control of fuel flow rate and air flow rate of a supersonic heat-airflow simulated test system

2020 ◽  
Vol 124 (1278) ◽  
pp. 1170-1189
Author(s):  
C. Cai ◽  
L. Guo ◽  
J. Liu
Keyword(s):  
Flow Rate ◽  
Control Algorithm ◽  
Air Flow ◽  
Coordinated Control ◽  
Test System ◽  
Gas Temperature ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Fuel Flow ◽  
Simulated Test

ABSTRACTThe gas temperature of the supersonic heat airflow simulated test system is mainly determined by the fuel and air flow rates which enter the system combustor. In order to realise a high-quality control of gas temperature, in addition to maintaining the optimum ratio of fuel and air flow rates, the dynamic characteristics of them in the combustion process are also required to be synchronised. Aiming at the coordinated control problem of fuel and air flow rates, the mathematical models of fuel and air supply subsystems are established, and the characteristics of the systems are analysed. According to the characteristics of the systems and the requirements of coordinated control, a fuzzy-PI cross-coupling coordinated control strategy based on neural sliding mode predictive control is proposed. On this basis, the proposed control algorithm is simulated and experimentally studied. The results show that the proposed control algorithm has good control performance. It cannot only realise the accurate control of fuel flow rate and air flow rate, but also realise the coordinated control of the two.

scholarly journals POLYMER WASTES’ FLOTATION SEPARATION RESEARCH RESULTS

2020 ◽  
Vol 6 (444) ◽  
pp. 50-58
Author(s):  
А. Volnenko ◽  
◽  
А. Leudanski ◽  
Y. Apimakh ◽  
B. Korganbayev ◽  
...  
Keyword(s):  
Liquid Layer ◽  
Flow Rate ◽  
Air Flow ◽  
Liquid Temperature ◽  
Air Flow Rate ◽  
Flotation Process ◽  
Flow Rates ◽  
Research Results ◽  
Air Bubble ◽  
Plastic Wastes

For separation of plastic wastes (polyamide (PA), acrylonitrile butadiene styrene (ABS) and polystyrene (PS), a flotation method is proposed. Using this method, the effect of concentration of surface-active substances (surfactants), which were used as polidocanol, sulphanole and a mixture of surfactants containing sodium laureth sulfate and diethanolamide, was studied. The research results analysis of the flotation separation of a mixture of crushed plastic wastes was carried out according to the calculated values of the extraction of a floated component ε and the purity of a concentrate β. It was noted that the maximum extraction of the floated component depends on the polymer and surfactant type. A mixture of surfactants at lower concentrations allows to achieve greater extraction of the floated component with less foaming ability. The research results on the extraction of polystyrene from the air flow rate at various concentrations of surfactants’ mixture show that the extraction has a maximum at a certain air flow rate. At low air flow rates, the working volume of liquid is not saturated enough with gas bubbles. If the optimal value of air flow rates is exceeded, many gas bubbles are formed that are not involved in the flotation process. The research results on the extraction of polystyrene from the aerated liquid layer height at various concentrations of surfactants’ mixture show that, at a low height of the aerated liquid layer, the probability of collision of a plastic particle with an air bubble is low and some potentially floated particles seek the bottom of an apparatus without having time to collide with an air bubble. When assessing the influence of liquid temperature on the flotation process, it was found that increasing the liquid temperature above 20°C leads to a sharp decrease in ABS and PS extraction. This is explained by the fact that the dependence of the surfactants’ foaming ability on the temperature is characterized by solubility curves and for most surfactants they have an extremum.

scholarly journals Evaluation of Izmir Tulum cheese pieces by drying with tray drier at different air flow rates and temperatures

2018 ◽  
Author(s):  
Nurcan Koca ◽  
Gulsah Kizilalp ◽  
Izel Polat ◽  
Müge Urgu
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Sensory Properties ◽  
Water Holding Capacity ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Physical Chemical ◽  
Tulum Cheese ◽  
Water Holding

Izmir tulum cheese pieces were dried using a tray dryer at different air flow rates (1.0 and 1.8 m/s) and temperatures (45oC, 55oC and 65oC). The increase in temperature and air flow rate increased bulk and tapped bulk densityand decreased the water holding capacity. The lowest lightness and highest redness were obtained in samples dried at 65oC. The samples dried at 55°C and 1 m/s had the highest flavor and overall impression scores. As a result, a dried cheese product to benefit from left-over pieces obtained during packaging  was developed, having advantages such as easy to transport, store and package.Keywords: Izmir Tulum cheese; tray dryer; physical, chemical and sensory properties.   

Evaluation of numerical modelling for a compact down-hole subsea gas-liquid separator for high gas content

2009 ◽  
Vol 49 (1) ◽  
pp. 433
Author(s):  
Shakil Ahmed ◽  
Mohamed Nabil Noui-Mehidi ◽  
Jamal Naser's ◽  
Gerardo Sanchez Soto ◽  
Edson Nakagawa
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Volume Fraction ◽  
Air Flow ◽  
Gas Content ◽  
Water Mixture ◽  
Air Flow Rate ◽  
Flow Rates ◽  
High Efficient ◽  
Liquid Separator

This paper describes the computational fluid dynamics (CFD) modelling of a laboratory scale gas-liquid separator designed for high gas content. The separator consists of two concentric pipes with swirl tube in the annular space between the pipes. The gas-liquid mixture comes tangentially from the side inlet and the system works with a combination of gravity and centrifugal forces to achieve a high-efficient gas-liquid separation. Three dimensional transient multi-phase fluid flows were solved to predict the velocity and volume fraction of each phase. The standard k- turbulence model was used for turbulence closure. The performance of the gas-liquid separator was visually established for a range of gas flow rates (271–495 L/min), with volume fraction (VF) =0.874–0.985 by observing the liquid carry over (LCO) regime where liquid was carried out in the gas stream. The liquid and gas flow rates at which the LCO was observed defines the upper operational range of the separator. Air-water mixture was used in the numerical simulations to keep consistent with the experiments. The pressure between the inlet and exit was validated against the experiments for different air-water flow rate combinations. The values were matched reasonably well for high air flow rate (495 L/min, VF=0.985) but were under-predicted for low air flow rate (271 L/min, VF=0.874). The air and water were mixed upstream of the inlet in the experiments and the pressure was measured at the start of the inlet. In case of numerical simulation the air and water were mixed at the inlet. This might cause the deviation of pressure when the air flow rate was low.

Analysis of Influencing Factors of Pressure Pre-Cooling Rate for Fruits and Vegetables

2013 ◽  
Vol 732-733 ◽  
pp. 581-584
Author(s):  
Qiang Wang ◽  
Fan Wang ◽  
Qi Wang ◽  
Feng Zhen Liu
Keyword(s):  
Cooling Rate ◽  
Fruits And Vegetables ◽  
Air Flow ◽  
Evaluation Index ◽  
Air Flow Rate ◽  
Cooling Process ◽  
Flow Rates ◽  
Different Shapes ◽  
Cooling Air Flow ◽  
Cooling Air

Cooling rate is an important evaluation index of pressure pre-cooling effect for fruits and vegetables. Experimental device of pressure pre-cooling for fruits and vegetables has been established. Pre-cooling process of golden pears has been tested. The key parameters which affected pressure pre-cooling 7/8 cooling time of golden pears such as different air flow rates, different shapes and sizes of vent hole and arrange form have been analyzed. The results show that it is better that cooling air flow rate is between 1.5 m/s and 2 m/s. Ellipse vent hole shape is the best vent hole style and key-groove vent hole is the worst. The cooling rate of stagger array form is faster than the parallel array form.

DEVELOPMENT OF AN ELECTRONIC AEROSOL SYSTEM FOR GENERATING MICROCAPSULES

2016 ◽  
Vol 78 (5-7) ◽  
Author(s):  
Wai Yean Leong ◽  
Chin Fhong Soon ◽  
Soon Chuan Wong ◽  
Kian Sek Tee
Keyword(s):  
Sodium Alginate ◽  
Air Flow ◽  
Electronic System ◽  
Syringe Pump ◽  
Air Flow Rate ◽  
Solution Flow ◽  
Flow Rates ◽  
Encapsulation Process ◽  
Compact Design ◽  
Simple Economic

The encapsulation of living cells in a variety of soft polymers or hydrogels is important, particularly for the generation of microtissues. Various techniques have been developed for the production of microcapsules to encapsulate cells but presented threat to the cells due to the harsh treatment during the encapsulation process.  In this paper, we propose a simple, economic and compact design of aerosol electronic system for producing different sizes of microcapsules. The aerosol system was developed with the incorporation of a conventional syringe pump and a customised air pump. The syringe pump purged the droplets of sodium alginate and air pump dispersed the droplets into microdroplets of sodium alginate which was then polymerised in the calcium chloride solution. In this system, the air flow rate from the air pump was controlled by a programmed microcontroller that received input instructions from a potentiometer. The suitable air flow rates that worked synchronously with the speed of the syringe pump were characterised. At 0.2 and 0.3 L/min of air flow and 20 µl/min of alginate solution flow, this device successfully generated round microcapsules with various sizes ranging from 100 to 350 µm.

Computational Fluid Dynamics (CFD) Analysis of Building Integrated Photovoltaic Thermal (BIPV/T) Systems

2014 ◽  
Author(s):  
Getu Hailu ◽  
TingTing Yang ◽  
Andreas K. Athienitis ◽  
Alan S. Fung
Keyword(s):  
Boundary Condition ◽  
Solar Radiation ◽  
Air Flow ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Transfer Coefficients ◽  
Domestic Water ◽  
Element Analysis ◽  
Flow Rates ◽  
T System

This paper presents CFD study of a BIPV/T system with forced convection. Air was circulated behind PV arrays and used as a coolant with various air flow rates (air velocities) to recover the thermal energy that could be used for space and/or domestic water heating. Turbulent flows were considered with Reynolds number ranging from 5199 to 9392. COMSOL Multiphysics finite element analysis (FEA) software was used to develop CFD models for the BIPV/T system using: (a) measured temperature profile at different flow rates, and (b) measured solar radiation as boundary condition. Predictions of the air temperature profiles inside the air flow channel and the backside of the PV were obtained and compared to experimentally obtained temperature profiles using both boundary conditions. In general, better agreement with the experimentally measured temperature profiles was obtained when the measured solar radiation was used as a boundary condition. The results of the study can be used to establish relationships between the average/local convective heat transfer coefficients and air flow velocity. The relationships obtained will also be useful for developing correlations and simple mathematical models that facilitate the design and optimization of different parts of the BIPV/T system, such as inlet regions.

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