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.

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.

AIR CURTAIN INCINERATOR TESTS

1983 ◽  
Vol 1983 (1) ◽  
pp. 33-38
Author(s):  
Keith F. Kruk
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Test System ◽  
Design Criteria ◽  
Front Wall ◽  
Water Spray ◽  
Air Flow Rate ◽  
Air Curtain ◽  
Operating Variables ◽  
Combustion Tests

ABSTRACT The use of an curtain incinerator to dispose of materials recovered from an oil spill was investigated for the Alaskan Beaufort Sea Oilspill Response Body (ABSORB). A series of combustion experiments was conducted in a prototype incinerator 10 feet wide by 10 feet long by 14 feet high. Combustion rates, emissions, and temperatures were monitored during the experiments. Operating variables investigated included air flow rate, direction of air into the combustion chamber, waste feed rate, water spray over the combustion zone, and the slant of the combustion chamber's front wall. Some of the major results were:Optimum air flow rate into the incinerator is 7,000 cubic feet per minute.The system performed satisfactorily at combustion rates exceeding 600 barrels per day.At 600 bbl/day, most emulsions burned with emissions less than 1 Ringelmann.Oil with 20-to-30 percent water burned most efficiently.Oil-saturated straw was consistently burned in the incinerator at measured emission levels of less than 1 Ringelmann.Combustion temperatures in the incinerator will exceed 2,000°F with an 18,500-Btu-per-pound oil. Included in this paper are details of the test system, results of combustion tests, and recommended design criteria for an arctic system.

Performance Analysis of Eductor Used for Main Control Room Ventilating in Nuclear Power Plant

2017 ◽  
Author(s):  
Xin Yu ◽  
Yuqing Lin ◽  
Yan Zhang
Keyword(s):  
Flow Rate ◽  
Nuclear Power ◽  
Air Flow ◽  
Test System ◽  
Air Pressure ◽  
Air Flow Rate ◽  
Control Room ◽  
Entrainment Ratio ◽  
Pressurized Water ◽  
Set Up

This paper proposes the experimental research for the performance of the air eductor used in main control room (MCR). The air eductor is used for emergency ventilating in advanced passive pressurized water reactor in accident. The compress air is supplied to the eductor as a power source and the indoor air is suctioned to the eductor. The performance of the eductor is related to the habitability of MCR. The entrainment ratio and the air pressure of discharge side are the main concerned performance. The entrainment ratio is a value that resulted from the compress air flow rate divided by the suction air flow rate. A test system was set up to test the performance of eductor. The experimental results show that the entrainment ratio of rectangle nozzle with compress air pressure 0.76MPa, 0.80MPa and 0.83MPa were 15.02, 15.04 and 15.06, respectively.

Dynamic Characterization of a Laboratory-Scale Thermal Pulse Combustor

2012 ◽  
Author(s):  
Sirshendu Mondal ◽  
Achintya Mukhopadhyay ◽  
Swarnendu Sen
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Singular Spectrum Analysis ◽  
Laboratory Scale ◽  
Series Data ◽  
Air Flow Rate ◽  
Fuel Flow Rate ◽  
Thermal Pulse ◽  
Fuel Flow ◽  
Pulse Combustor

Pulse combustors are widely applied for heating, drying and even propulsion applications because of their higher efficiency, higher heat transfer rates and lower emission than steady combustors. However, fundamentals of this pulse combustor remain till date largely unexplored. Experiments are conducted on a laboratory-scale thermal pulse combustor. The set-up consists of an upstream section, the combustor and the tailpipe. The optical signal from the flame is measured with a photomultiplier tube and pressure fluctuations are measured using a dynamic pressure transducer. The time series data reconstructed with SSA (Singular Spectrum Analysis) reveals that at a given air flow rate as the fuel flow rate is reduced, three distinct regimes are observed: strongly pulsating, weakly pulsating and non-pulsating. Nonlinear analysis suggests the existence of quasiperiodic orbits for the pulsating cases. The phase difference between pressure and heat release rate fluctuations confirm sustained instability for the pulsating cases. The characteristic frequency is found to decrease with decrease in fuel flow rate and increase in tailpipe length for a given air flow rate. Different orientation of fuel inlet has been implemented to achieve pulsating combustion under lean fuel conditions.

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.

Two-Phase Flow Visualization for a Hybrid Heat Sink

2018 ◽  
Author(s):  
Danish Rahman ◽  
Ahmad Almomani ◽  
Ibrahim Hassan ◽  
Yasser Al-Hamidi ◽  
Aziz Rahman
Keyword(s):  
Flow Rate ◽  
Slug Flow ◽  
Air Flow ◽  
Plug Flow ◽  
Cross Flow ◽  
Flow Regimes ◽  
Air Flow Rate ◽  
Two Phase ◽  
Flow Rates ◽  
Impingement Jet

This paper aimed to study two-phase flow under adiabatic conditions through the process of flow visualization. This was done through the use of a test section with a cross flow and a jet impingement (swirl jet). The flow regimes under different air-water flow rates were determined using a high-speed camera that recorded digital videos. For each of the flow rates the pressure differential between the inlet and the outlets were measured. Through the pressure drop it is proposed that the types of flow regimes may later be able to be predicted. Nine air-water flow rates were considered to collect data and generate a flow map for the impingement jet and cross flow. The major observed flow regimes within the crossflow and impingement jet followed the predicted trend with bubbly and plug flow in the former, and slug flow in the latter. It was further observed that increasing the air flow rate increased the likelihood of bubbly and plug flow in both the cross-flow and impingement jet. In the cross flow, a lower air flow rate resulted in bubbly flow while within the impingement jet, a lower air flow rate resulted in slug flow.

scholarly journals Dynamic Permeability of Porous Elastic Fabrics

2012 ◽  
Vol 7 (2_suppl) ◽  
pp. 155892501200702 ◽  
Author(s):  
Phillip W. Gibson ◽  
Kenneth Desabrais ◽  
Thomas Godfrey
Keyword(s):  
Flow Rate ◽  
High Pressures ◽  
Air Flow ◽  
High Strength ◽  
Fluid Structure Interactions ◽  
Air Flow Rate ◽  
Flow Rates ◽  
Dimensional Changes ◽  
Permeability Changes ◽  
Dynamic Permeability

This paper describes permeability measurements for porous fabrics as influenced by strain, humidity, air flow rate, and fabric elasticity. The focus is on standard parachute fabrics, where the fabric's porosity and air permeability influence the rate of steady-state descent, and also affect the complicated fluid-structure interactions taking place during parachute opening and deployment. High strength nylon parachute fabrics showed relatively small permeability changes due to strain, humidity, and flow rate. Comparative measurements on elastomeric fabrics showed much larger changes in air flow due to fabric dimensional changes at high pressures and flow rates. Elastomeric fabrics that stretch and change permeability in response to higher pressures and flow rates may be able to reduce the “opening shock” during the parachute deployment phase.

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