Nonmonotonic Effects of Aerodynamic Force on Droplet Size of Prefilming Air-Blast Atomization

This paper presents an air-oriented spray cooling system (SCS) integrated with a two-phase ejector for the thermal management system. Considering its aeronautical application, the spray nozzle in the SCS is an air-blast one. Heat transfer performance (HTP) of air-water spray cooling was studied experimentally on the basis of the ground-based test. Factors including pressure difference between water-inlet-pressure (WIP) and spray cavity one (PDWIC) and the spray volumetric flow rate (SVFR) were investigated and discussed. Under a constant operating condition, the cooling capacity can be promoted by the growth factors of the PDWIC and SVFR with the values from 51.90 kPa to 235.35 kPa and 3.91 L ⋅ h − 1 to 14.53 L ⋅ h − 1 , respectively. Under the same heating power, HTP is proportional to the two dimensionless parameters Reynolds number and Weber number due to the growth of droplet-impacting velocity and droplet size as the increasing of PDWIC or SVFR. Additionally, compared with the factor of the droplet size, the HTP is more sensitive to the variation in the droplet-impacting velocity. Based on the experimental data, an empirical experimental correlation for the prediction of the dimensionless parameter Nusselt number in the non-boiling region with the relative error of only ± 10 % was obtained based on the least square method.

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Development and Experimental Investigation of a Tubular Combustor for Pyrolysis Oil Burning

Volume 3A: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration ◽

10.1115/gt2014-26343 ◽

2014 ◽

Author(s):

Martin Beran ◽

Lars-Uno Axelsson

Keyword(s):

Experimental Investigation ◽

Gas Turbine ◽

Droplet Size ◽

Gas Turbines ◽

Alternative Fuels ◽

Fossil Fuels ◽

Heat Content ◽

Pyrolysis Oil ◽

Load Range ◽

Air Blast

The growing demand for more economical and environmentally friendly power generation forces the industry to search for fuels that can replace the conventional fossil fuels. This has led to significant developments in the production of alternative fuels during the last years, which have made them a reliable and relatively efficient source of energy. One example of these alternative fuels is the pyrolysis oil. However, higher viscosity, lower heat content, limited chemical stability and its ability to create sediment make pyrolysis oil challenging for gas turbines. The OPRA OP16 gas turbine is an all radial single-shaft gas turbine rated at 1.9 MW. The all radial design, together with the lack of intricate cooling geometries in the hot section, makes this gas turbine suitable for operation on these fuels. This paper presents an experimental investigation of pyrolysis oil combustion in a tubular combustor developed especially for low-calorific fuels. The experiments have been performed in an atmospheric combustion test rig and the results have been compared to the results obtained from ethanol and diesel combustion. It was found that it was possible to burn pure pyrolysis oil in the load range between 70 to 100% with a combustion efficiency exceeding 99% and without creation of sediments on the combustor inner wall. It was found that the NOx emissions were similar for pyrolysis oil and diesel, whereas the CO emissions were twice as high for pyrolysis oil. A comparison between the air blast nozzle and the pressure nozzle was performed. The air blast nozzle was found to be more suitable due to its better performance over a wider operating range and that it is more resistant to erosion and abrasion. It was found that the maximum allowed droplet size of the pyrolysis oil spray should be about 50–70% of the droplet size for diesel fuel.

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Characterization of the Effects of Droplet Size, Air Blast Strength, and Angle on Spray Distribution and Efficacy of a Buffalo Turbine Barrier Treatment Sprayer

Journal of ASTM International ◽

10.1520/jai103367 ◽

2011 ◽

Vol 8 (5) ◽

pp. 103367

Author(s):

S. W. Dean ◽

Jane A. S. Bonds ◽

Cindy Mulla ◽

Ed Hunter

Keyword(s):

Droplet Size ◽

Air Blast ◽

Spray Distribution

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DEVELOPMENT OF AN AIR-BLAST ATOMIZER FOR INDEPENDENT CONTROL OF DROPLET SIZE AND SPRAY DENSITY

Atomization and Sprays ◽

10.1615/atomizspr.v14.i3.40 ◽

2004 ◽

Vol 14 (3) ◽

pp. 265-288 ◽

Cited By ~ 3

Author(s):

H. L. Clack ◽

C. P. Koshland ◽

D. Lucas ◽

R. F. Sawyer

Keyword(s):

Droplet Size ◽

Independent Control ◽

Air Blast ◽

Spray Density

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Development and Experimental Investigation of a Tubular Combustor for Pyrolysis Oil Burning

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4028450 ◽

2014 ◽

Vol 137 (3) ◽

Cited By ~ 11

Author(s):

Martin Beran ◽

Lars-Uno Axelsson

Keyword(s):

Experimental Investigation ◽

Gas Turbine ◽

Droplet Size ◽

Gas Turbines ◽

Alternative Fuels ◽

Fossil Fuels ◽

Heat Content ◽

Pyrolysis Oil ◽

Load Range ◽

Air Blast

The growing demand for more economical and environmentally friendly power generation forces the industry to search for fuels that can replace the conventional fossil fuels. This has led to significant developments in the production of alternative fuels during the last years, which have made them a reliable and relatively efficient source of energy. One example of these alternative fuels is the pyrolysis oil. However, higher viscosity, lower heat content, limited chemical stability, and its ability to create sediment make pyrolysis oil challenging for gas turbines. The OPRA OP16 gas turbine is an all radial single-shaft gas turbine rated at 1.9 MW. The all radial design, together with the lack of intricate cooling geometries in the hot section, makes this gas turbine suitable for operation on these fuels. This paper presents an experimental investigation of pyrolysis oil combustion in a tubular combustor developed, especially for low-calorific fuels. The experiments have been performed in an atmospheric combustion test rig, and the results have been compared to the results obtained from ethanol and diesel combustion. It was found that it was possible to burn pure pyrolysis oil in the load range between 70% and 100% with a combustion efficiency exceeding 99% and without creation of sediments on the combustor inner wall. It was found that the NOx emissions were similar for pyrolysis oil and diesel, whereas the CO emissions were twice as high for pyrolysis oil. A comparison between the air blast nozzle and the pressure nozzle was performed. The air blast nozzle was found to be more suitable due to its better performance over a wider operating range and that it is more resistant to erosion and abrasion. It was found that the maximum allowed droplet size of the pyrolysis oil spray should be about 50–70% of the droplet size for diesel fuel.

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Prediction of droplet size distribution in sprays of prefilming air-blast atomizers

Chemical Engineering Science ◽

10.1016/j.ces.2005.10.012 ◽

2006 ◽

Vol 61 (6) ◽

pp. 1741-1747 ◽

Cited By ~ 48

Author(s):

Hai-Feng Liu ◽

Xin Gong ◽

Wei-Feng Li ◽

Fu-Chen Wang ◽

Zun-Hong Yu

Keyword(s):

Size Distribution ◽

Droplet Size ◽

Droplet Size Distribution ◽

Air Blast

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The Selection of Ceramic Dry Granulating Machine Spray Device Based on the DPM Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.716-717.573 ◽

2014 ◽

Vol 716-717 ◽

pp. 573-576

Author(s):

Nan Xing Wu ◽

Tian Tian Zhan ◽

Zhu Ting Jiang

Keyword(s):

Flow Field ◽

Droplet Size ◽

Droplet Size Distribution ◽

Air Blast ◽

Dry Granulation ◽

Nozzle Pressure ◽

Simulation Results ◽

Pressure Swirl ◽

Best Fit ◽

Selection Of

In order to improve the dispersity of true particles in the process of ceramic dry granulation, by adding a sprayer in the upper of granulation chamber to make water spray into droplets, which greatly increases the contact area of liquid water and powder. The atomization flow field of plain-orifice-nozzle, pressure-swirl-nozzle, air-blast-nozzle, effervescent-nozzle with 1mm nozzle diameter is simulated based on the DPM model, obtaining the droplet size distribution cloud picture and atomization flow field simulative cloud picture of four kinds of nozzle. The simulation results show that the average droplet size of pressure-swirl-nozzle is the minimum and the disperisity of atomization flow field of air-blast-nozzle, effervescent-nozzle, pressure-swirl-nozzle, plain-orifice-nozzle increases in turn. In terms of the average droplet size and the dispersity of atomization flow field, the droplet dispersity of pressure-swirl-nozzle is better and the average droplet size is the minimum, which is most beneficial to solve the problem of fully dispersity of really particle. Therefore, pressure-swirl-nozzle is best fit for the spray device of ceramic dry granulation.

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Research on the Impact of the Characteristic Parameters of Air-blast Rotating Cage Sprayer to Droplet Size

10.13031/2013.41969 ◽

2012 ◽

Author(s):

Hongping Zhou ◽

Linyun Xu ◽

Wei Song ◽

Yemin Cui ◽

Hua Cui ◽

...

Keyword(s):

Droplet Size ◽

Characteristic Parameters ◽

Air Blast ◽

The Impact

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