Computational and Experimental Investigation of Emissions in a Highly Humidified Premixed Flame

2003 ◽  
Author(s):  
Fredrik Hermann ◽  
Jens Klingmann ◽  
Rolf Gabrielsson
Keyword(s):  
Air Temperature ◽  
Combustion Efficiency ◽  
Reaction Scheme ◽  
Operating Conditions ◽  
Aerodynamic Load ◽  
Inlet Temperature ◽  
Atmospheric Conditions ◽  
Air Inlet ◽  
Stirred Reactor ◽  
Maximum Humidity

Emission formation and flame stability were investigated, both experimentally and computationally, for premixed combustion with varying amounts of water vapor in the mixture. Emission measurements were made in a gas turbine combustor at atmospheric conditions, using Danish Natural Gas (NG) as fuel. The emissions were mapped as a function of humidity, inlet air temperature, equivalence ratio and aerodynamic load. Operating conditions were chosen to match what can be expected from e.g. an EvGT cycle for power generation. The inlet air temperature was slightly lower than the inlet temperatures that would be found in a recuperated cycle. The degree of humidity was varied from 0w% to 33w% of the airflow in the experiment, while the air inlet temperature was varied from 500K to 800K. Computations were made using a single Perfectly Stirred Reactor (PSR) model and a reaction scheme with 821 reactions and 69 species. It was found that the NOx emissions were strongly reduced by the addition of water. Most of this decrease vanishes in practical combustion since richer combustion is required to keep CO emissions (combustion efficiency) at a tolerable level. The maximum humidity was found to be dependent on inlet air temperature and aerodynamic load. In this experiment, the maximum humidity achieved was 33%.

scholarly journals Characteristics of a Non-Premixed Rotating Detonation Combustor Using Natural Gas-Hydrogen Blend at Elevated Air-Preheat Temperature and Backpressure

2018 ◽  
Author(s):  
Arnab Roy ◽  
Donald Ferguson ◽  
Todd Sidwell ◽  
Peter Strakey
Keyword(s):  
Experimental Study ◽  
Natural Gas ◽  
Detonation Wave ◽  
Inlet Temperature ◽  
Operational Mode ◽  
Atmospheric Conditions ◽  
Theoretical Understanding ◽  
Air Inlet ◽  
Continuous Detonation ◽  
Rotating Detonation

Operational characteristics of an air breathing Rotating Detonation Combustor (RDC) fueled by natural gas-hydrogen blends are discussed in this paper. Experiments were performed on a 152 mm diameter uncooled RDC with a combustor to inlet area ratio of 0.2 at elevated inlet temperature and combustor pressure while varying the fuel split between natural gas and hydrogen over a range of equivalence ratios. Experimental data from short-duration (∼6sec) tests are presented with an emphasis on identifying detonability limits and exploring detonation stability with the addition of natural gas. Although the nominal combustor used in this experiment was not specifically designed for natural gas-air mixtures, significant advances in understanding conditions necessary for sustaining a stable, continuous detonation wave in a natural gas-hydrogen blended fuel were achieved. Data from the experimental study suggests that at elevated combustor pressures (2–3bar), only a small amount of natural gas added to the hydrogen is needed to alter the detonation wave operational mode. Additional observations indicate that an increase in air inlet temperature (up to 204°C) at atmospheric conditions significantly affects RDC performance by increasing deflagration losses through an increase in the number of combustion (detonation/Deflagration) regions present in the combustor. At higher backpressure levels the RDC exhibited the ability to achieve stable detonation with increasing concentrations of natural gas (with natural gas / hydrogen-air blend). However, losses tend to increase at intermediate air preheat levels (∼120°C). It was observed that combustor pressure had a first order influence on RDC stability in the presence of natural gas. Combining the results from this limited experimental study with our theoretical understanding of detonation wave fundamentals provides a pathway for developing an advanced combustor capable of replacing conventional constant pressure combustors typical of most power generation processes with one that produces a pressure gain.

scholarly journals Effect of Biodegradable Binder Properties and Operating Conditions on Growth of Urea Particles in a Fluidized Bed Granulator

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2320 ◽  
Author(s):  
Ehsan Zhalehrajabi ◽  
Kok Keong Lau ◽  
Ku Zilati Ku Shaari ◽  
Seyed Mojib Zahraee ◽  
Seyed Hadi Seyedin ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Air Temperature ◽  
Scale Up ◽  
Cost Effective ◽  
Stokes Number ◽  
Operating Conditions ◽  
Air Velocity ◽  
Air Inlet ◽  
Lower Temperature ◽  
Penetration Time

Granulation is an important step during the production of urea granules. Most of the commercial binders used for granulation are toxic and non-biodegradable. In this study, a fully biodegradable and cost-effective starch-based binder is used for urea granulation in a fluidized bed granulator. The effect of binder properties such as viscosity, surface tension, contact angle, penetration time, and liquid bridge bonding force on granulation performance is studied. In addition, the effect of fluidized bed process parameters such as fluidizing air inlet velocity, air temperature, weight of primary urea particles, binder spray rate, and binder concentration is also evaluated using response surface methodology. Based on the results, binder with higher concentration demonstrates higher viscosity and higher penetration time that potentially enhance the granulation performance. The viscous Stokes number for binder with higher concentration is lower than critical Stokes number that increases coalescence rate. Higher viscosity and lower restitution coefficient of urea particles result in elastic losses and subsequent successful coalescence. Statistical analysis indicate that air velocity, air temperature, and weight of primary urea particles have major effects on granulation performance. Higher air velocity increases probability of collision, whereby lower temperature prevents binder to be dried up prior to collision. Findings of this study can be useful for process scale-up and industrial application.

Emissions Performance of the Macrolaminate Premixer Tested Under Simulated Engine Conditions

2003 ◽  
Author(s):  
Adel Mansour ◽  
Michael A. Benjamin
Keyword(s):  
Pressure Drop ◽  
Flame Temperature ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Nox Formation ◽  
Pressure Drops ◽  
Lean Blowout ◽  
Stirred Reactor ◽  
Pressure Swirl ◽  
High Degree

Single injector, high pressure, rig evaluation of the prototype Parker macrolaminate dual fuel premixer (previously tested at NETL, see Mansour et al., 2001) [1] with pressure swirl macrolaminate atomizers was conducted under simulated engine operating conditions running on No. 2 diesel fuel (DF2). Emissions, oscillations and lean blowout (LBO) performance on liquid fuel at high, part and no load operating points (pressures of 160, 100, 120 psig, and inlet temperatures of 690, 570, 590°F, respectively) and various pressure drops (ΔP/P) and air fuel ratio conditions were investigated. The results indicate that the Parker premixer design has the potential to reduce the DF2 NOX emission to below 15 ppmv, 15% O2. At simulated high load conditions with a nominal flame temperature (TPZ) of 2700°F, the NOX and CO emissions are approximately 10 and 2.5 ppmv at 15% O2, respectively. These results compare extremely favorable to existing commercially available premixer technologies tested under similar rig operating conditions. More importantly, the NOX yield for the Parker Macrolaminate premixer appears to be independent of operating conditions (from high to no load and various pressure drop conditions). Variations in combustor pressure, inlet temperature (T2) and residence time (τ) or pressure drop (ΔP/P) does not seem to have an effect on the formation of NOX. According to Leonard and Stegmaier (1993) [2], insensitivity of NOX formation to operating conditions is a good indication of high degree of premixing. Additionally, the premixer NOX data is only 1 to 2 ppmv higher than the jet stirred reactor (JSR) results (ran at T2 = 661°F, PCD = 14.7 psi and TPZ = 2762°F with similar DF2) of Lee et al., 2001 [3], further confirming the quality of premixing achieved. Combustion driven oscillations was not investigated by tuning the rig so that oscillations would not be a factor.

Theoretical Performance of Silica Gel Desiccant Wheel

2019 ◽  
Vol 7 (3) ◽  
pp. 66-74
Author(s):  
Zainab Mahdi Salih ◽  
Abdulsalam D. M.Hassan ◽  
Amer Majeed Al-Dabagh
Keyword(s):  
Silica Gel ◽  
Air Temperature ◽  
Inlet Temperature ◽  
Moisture Removal ◽  
Humidity Ratio ◽  
Desiccant Wheel ◽  
Operational Conditions ◽  
Removal Capacity ◽  
Air Inlet ◽  
Theoretical Performance

Abstract— Silica gel is a substance commonly used in desiccant wheel, which in turn is used in many applications to reduce moisture from the supplied air to a specific space. In this research,  the effect of different operational conditions on the performance of silica gel wheel were studied. The desiccant wheel, which has been used, has a diameter of 55 cm and thickness of 20 cm. It contains 34 kg of silica gel and rotate at a speed of 30 rph. The theoretical performance coefficients of the desiccant wheel which have been studied include ,moisture removal capacity(MRC),dehumidification performance(DCOP),latent coefficient of performance (COPlat), and desiccant wheel effectiveness(ϵ_d). The theoretical investigation of these coefficients was done by using Novel Aire Technology software program (Simulation program of desiccant wheel) (2012). While the operational conditions like process air (humid air)inlet temperature between(30 to 43.4)0C, process air inlet humidity ratio between (0.011 to 0.019)kg/kgdry air ,regeneration air inlet temperature between (56.5 to 70)0C,and process air mass flow rate between(0.0814 to 0.199)kg/s. The results shows that the effectiveness and the moisture removal capacity have the same behavior increase with the increasing in mass flow rate from(0.0814 to 0.199) kg/s, humidity ratio from(11 to19)g/kgdry air, and regeneration air temperature from(56 t0 70)oC. But they reduces with increasing of inlet process air temperature from(30 to43.4)oC..

Development of a Simulation Analysis Environment for Ventilated Slab Systems

2014 ◽  
Author(s):  
Benjamin Park ◽  
Moncef Krarti
Keyword(s):  
Simulation Analysis ◽  
Energy Performance ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Hollow Core ◽  
Simulation Environment ◽  
Core Diameter ◽  
Air Inlet ◽  
Thermal Bridge ◽  
Parametric Analyses

This paper presents a simulation environment developed to assess the energy performance of hollow core ventilated slab systems. The developed simulation environment combines a transient finite difference solution of a ventilated slab system with an RC network model for a multi-floor building. The developed simulation environment takes into account ventilated slab system thermal bridge effects on the energy performance of multi-floor buildings. The predictions of the developed simulation environment are verified against those obtained from a detailed whole-building energy simulation tool. In addition, several parametric analyses are performed to determine the performance of ventilated slab systems under various design and operating conditions. In particular, the parametric analyses include the effect of supply air inlet temperature, air mass flow rate, hollow core depth, and hollow core diameter. In particular, it is found that due to increased heat transfer through slab edge increases due to thermal bridge effects, ventilated slab requires 5% more heating and 7% more cooling energy end-uses.

scholarly journals Air-side performance of a micro-channel heat exchanger in wet surface conditions

2017 ◽  
Vol 21 (1 Part A) ◽  
pp. 375-385 ◽  
Author(s):  
Raviwat Srisomba ◽  
Lazarus Asirvatham ◽  
Omid Mahian ◽  
Ahmet Dalkılıç ◽  
Mohamed Awad ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Relative Humidity ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Micro Channel ◽  
Surface Conditions ◽  
Air Inlet ◽  
Wet Surface

The effects of operating conditions on the air-side heat transfer, and pressure drop of a micro-channel heat exchanger under wet surface conditions were studied experimentally. The test section was an aluminum micro-channel heat exchanger, consisting of a multi-louvered fin and multi-port mini-channels. Experiments were conducted to study the effects of inlet relative humidity, air frontal velocity, air inlet temperature, and refrigerant temperature on air-side performance. The experimental data were analyzed using the mean enthalpy difference method. The test run was performed at relative air humidities ranging between 45% and 80%; air inlet temperature ranges of 27, 30, and 33?C; refrigerant-saturated temperatures ranging from 18 to 22?C; and Reynolds numbers between 128 and 166. The results show that the inlet relative humidity, air inlet temperature, and the refrigerant temperature had significant effects on heat transfer performance and air-side pressure drop. The heat transfer coefficient and pressure drop for the micro-channel heat exchanger under wet surface conditions are proposed in terms of the Colburn j factor and Fanning f factor.

scholarly journals Gas Turbine Combustion Efficiency

1985 ◽  
Author(s):  
Barry Schlein
Keyword(s):  
Unique Feature ◽  
Iterative Solution ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Fuel Flow ◽  
Flow Pressure ◽  
High Mach ◽  
Engine Type

A method of correlating combustor efficiency as a function of geometry and operating conditions is presented. A simple equation correlates all the data for a given engine type with a single parameter. The correlating parameter is a function of fuel flow, pressure, temperature and volume in a form similar to others in the literature. The unique feature of the correlating parameter is its use of internal gas temperature rather than the commonly used combustor inlet temperature. The result is an equation requiring an iterative solution since combustion efficiency is a part of the correlating parameter. With use of a computer this is easily handled. The correlation fits engine data over all flight conditions from high altitude, high Mach number to sea level idle. The correlation is compared to engine test data for several engines.

scholarly journals Spray-dried tomato powder: reconstitution properties and colour

2008 ◽  
Vol 51 (4) ◽  
pp. 607-614 ◽  
Author(s):  
Alexandre Santos de Sousa ◽  
Soraia Vilela Borges ◽  
Natália Ferreira Magalhães ◽  
Hevandro Vaz Ricardo ◽  
Aline Damico Azevedo
Keyword(s):  
Moisture Content ◽  
Air Temperature ◽  
Colour Index ◽  
Inlet Temperature ◽  
Feed Flow Rate ◽  
Air Inlet ◽  
Colour Parameter ◽  
Tomato Pulp ◽  
Tomato Powder ◽  
Spray Dried

Powdered tomato was produced by spray drying the tomato pulp. A full 2³ factorial design with the central point was used, varying the feed flow rate (127-276 g/min), air inlet temperature (200-220ºC) and the atomisation speed (25,000-35,000 rpm). The responses analysed were: moisture content, solubility, wettability consistency and colour, but the factors only significantly affected the colour parameter. All the samples became significantly darker and less red with an increase of the variables under study. A low atomisation speed (25,000 rpm) and lower inlet air temperature (220ºC) produced the powders with a higher colour index (a/b) and less darkening.

Emissions Performance of the Parker Macrolaminate Premixer Tested Under Simulated Engine Conditions

2004 ◽  
Vol 126 (3) ◽  
pp. 465-471
Author(s):  
Adel Mansour ◽  
Michael A. Benjamin
Keyword(s):  
Pressure Drop ◽  
Liquid Fuel ◽  
Flame Temperature ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Nox Formation ◽  
Pressure Drops ◽  
Lean Blowout ◽  
Stirred Reactor ◽  
Fuel Nox

Single-injector high-pressure rig evaluation of the prototype Parker macrolaminate dual fuel premixer (previously tested at NETL, Mansour et al., 2001) with pressure swirl macrolaminate atomizers was conducted under simulated engine operating conditions running on No. 2 diesel fuel (DF2). Emissions, oscillations and lean blowout (LBO) performance on liquid fuel at high, part and no load operating points (pressures of 160, 100, 120 psig, and inlet temperatures of 690, 570, 590°F, respectively) and various pressure drops (ΔP/P) and air fuel ratio conditions were investigated. The results indicate that the Parker premixer design has the potential to reduce the DF2 NOX emission to below 15 ppmv, 15% O2. At simulated high load conditions with a nominal flame temperature TPZ of 2700°F, the NOX and CO emissions are approximately 10 and 2.5 ppmv at 15% O2, respectively. These NOX results have not been corrected for fuel bound nitrogen (FBN). From the studies of Lee (2000), small amounts of FBN in the liquid fuel generally are completely converted over to fuel NOX under lean premixed conditions. The fuel tested has a nominal 60 ppmw of FBN which converts to an estimated fuel NOX of 4 ppmv at 15% O2. These results compare extremely favorable to existing commercially available premixer technologies tested under similar rig operating conditions. More importantly, the NOX yield for the Parker Macrolaminate premixer appears to be independent of operating conditions (from high to no load and various pressure drop conditions). Variations in combustor pressure, inlet temperature T2 and residence time (τ) or pressure drop (ΔP/P) does not seem to have an effect on the formation of NOX. According to Leonard and Stegmaier (1993), insensitivity of NOX formation to operating conditions is a good indication of high degree of premixing. Additionally, the premixer NOX data is only 1 to 2 ppmv higher than the jet stirred reactor (JSR) results (ran at T2=661°F,PCD=1 atm and TPZ=2762°F with similar DF2) of Lee et al. (2001) further confirming the quality of premixing achieved. Combustion driven oscillations was not investigated by tuning the rig so that oscillations would not be a factor.

scholarly journals Microencapsulation of the aroma from Capsicum chinense Jacq. cv. Habanero

2020 ◽  
Vol 49 (3) ◽  
pp. 321-329
Author(s):  
J.A. Pino ◽  
E. Sauri-Duch ◽  
O. Sosa-Moguel ◽  
C.A. Can-Cauich ◽  
V.M. Moo-Huchin ◽  
...  
Keyword(s):  
Moisture Content ◽  
Air Temperature ◽  
Gum Arabic ◽  
Inlet Temperature ◽  
Chilli Pepper ◽  
Independent Variables ◽  
Air Inlet ◽  
Encapsulation Process ◽  
Optimisation Model ◽  
Response Variables

An aroma distillate with the odour note described as ‘fresh Habanero chilli pepper' was obtained from hydrodistillation of the fruit. GC-MS analysis of the volatile constituents from the aroma distillate allowed the identification of 100 compounds, most of them esters followed by aldehydes, alcohols, terpenes, ketones, and acids. Encapsulation process of the aroma distillate by spray drying was optimised using response surface methodology. Independent variables were inlet air temperature (150-200 °C) and carrier (maltodextrin 10 DE and gum arabic in 2:1 ratio) content (10-20% wb), while response variables were powder moisture and volatiles retention. Moisture content of the powder varied inversely proportional to the air temperature, while the volatile retention was directly related. Retention of volatiles in the powder increased when the carrier content increased, while this factor negatively affected moisture content. Based on the optimisation model of the response variables, the powder with the highest flavour quality was obtained with an air inlet temperature of 200 °C and 20% wb carrier content, with 4% moisture content and 88.6% volatiles retention.

Sign in / Sign up

Export Citation Format

Share Document