THERMAL SCIENCE

International Scientific Journal

Shangzhi Yu

,

Qinglong Xie

,

Xiaoning Mao

,

Ying Duan

,

Yong Nie

HEAT TRANSFER IN A NOVEL MICROWAVE HEATING DEVICE COUPLED WITH ATOMIZATION FEEDING

ABSTRACT
The heat transfer characteristics of the microwave heating coupled with atomization feeding were investigated using ethanol as the spray medium on a pressure swirl nozzle. The effects of spray height, flow rate and temperature on the sauter mean diameter of atomized droplets were examined. The results showed that the droplet sauter mean diameter was 12-130 μm, which increased with the spray height and decreased with the flow rate and temperature of spray medium. Through the fitting of the experimental data, the dimensionless correlation of the droplet sauter mean diameter which was based on orifice diameter, Reynolds and Ohnesorge numbers was obtained. The calculated results were basically consistent with the experimental data within 15% error. The heat transfer characteristics of atomized droplets on high temperature surface of SiC bed heated by microwave were then investigated. The effects of spray flow rate, spray height, and spray temperature on the heat transfer characteristics were examined. The power of spray heat transfer decreased with the temperature and increased with the spray flow rate and spray height. The dimensionless correlation to describe the heat transfer characteristics of atomized droplets on the high temperature SiC surface under the microwave heating was obtained which included thermophysical properties of spray medium, spray parameters, and temperatures of the high temperature bed surface and spray medium, with the error of ±20%. These correlations can be used to predict the sauter mean diameter of the atomized droplets and the power of spray heat transfer in the microwave heating process.
KEYWORDS
microwave heating, spray, heat transfer characteristics, Sauter mean diameter (SMD), Dimensionless correlation
PAPER SUBMITTED: 2021-05-18
PAPER REVISED: 2021-09-01
PAPER ACCEPTED: 2021-09-06
PUBLISHED ONLINE: 2021-10-10
DOI REFERENCE: https://doi.org/10.2298/TSCI210518288Y
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2022, VOLUME 26, ISSUE Issue 2, PAGES [1185 - 1195]
REFERENCES
  1. Nie, Y., et al., Microwave-Assisted Pyrolysis Of Methyl Ricinoleate For Continuous Production Of Undecylenic Acid Methyl Ester (UAME), Bioresour. Technol., 186 (2015), pp. 334-337
  2. Yu, S., et al., Pyrolysis Of Methyl Ricinoleate By Microwave-Assisted Heating Coupled With Atomization Feeding, J. Anal. Appl. Pyrolysis, 135 (2018), pp. 176-183
  3. Yu, S., et al., Three-Dimensional Simulation Of A Novel Microwave-Assisted Heating Device For Methyl Ricinoleate Pyrolysis, Appl. Therm. Eng., 153 (2019), November 2018, pp. 341-351
  4. Motasemi, F., Afzal, M.T., A Review On The Microwave-Assisted Pyrolysis Technique, Renew. Sustain. Energy Rev., 28 (2013), 8, pp. 317-330
  5. Wu, W., et al., Temperature Field Distribution Analysis For Cargo Oil On Microwave Heating Process, Therm. Sci., 24 (2020), 5, pp. 3413-3421
  6. Fu, J.J., et al., Microwave Heating: A Potential Pretreating Method For Bamboo Fiber Extraction, Therm. Sci., 21 (2017), 4, pp. 1695-1699
  7. Xie, Q., et al., Fast Microwave-Assisted Catalytic Pyrolysis Of Sewage Sludge For Bio-Oil Production, Bioresour. Technol., 172 (2014), pp. 162-168
  8. Cheng, W., et al., Spray Cooling And Flash Evaporation Cooling: The Current Development And Application, Renew. Sustain. Energy Rev., 55 (2016), pp. 614-628
  9. Xie, Q., et al., Effects Of Multiple-Nozzle Distribution On Large Scale Spray Cooling Via Numerical Investigation, Therm. Sci., 2018 (2018), 5, pp. 3015-3024
  10. Chen, Z., et al., Numerical Simulation Of Single-Nozzle Large Scale Spray Cooling On Drum Wall, Therm. Sci., 22 (2018), 1, pp. 359-370
  11. Nie, Y., et al., Device and process for producing undecylenic acid methyl ester using methyl ricinoleate as raw material
  12. Mao, X., et al., Predictive Models For Characterizing The Atomization Process In Pyrolysis Of Methyl Ricinoleate, Chinese J. Chem. Eng., 28 (2020), 4, pp. 1023-1028
  13. Cheng, W., et al., Spray Characteristics And Spray Cooling Heat Transfer In The Non-Boiling Regime, Energy, 36 (2011), 5, pp. 3399-3405
  14. Zhang, W., et al., Enhancement Mechanism Of High Alcohol Surfactant On Spray Cooling: Experimental Study, Int. J. Heat Mass Transf., 126 (2018), pp. 363-376
  15. Bhatt, N.H., et al., Enhancement Of Heat Transfer Rate Of High Mass Flux Spray Cooling By Ethanol-Water And Ethanol-Tween20-Water Solution At Very High Initial Surface Temperature, Int. J. Heat Mass Transf., 110 (2017), pp. 330-347
  16. Moffat, R.J., Describing The Uncertainties In Experimental Results, Exp. Therm. Fluid Sci., 1 (1988), 1, pp. 3-17
  17. Zhang, T., et al., Spray Characteristics Of Pressure-Swirl Nozzles At Different Nozzle Diameters, Appl. Therm. Eng., 121 (2017), pp. 984-991
  18. Cheng, W., et al., Experimental And Theoretical Investigation Of Surface Temperature Non-Uniformity Of Spray Cooling, Energy, 36 (2011), 1, pp. 249-257
  19. Lasheras, J.C., et al., Break-Up And Atomization Of A Round Water Jet By A High-Speed Annular Air Jet, J. Fluid Mech., 357 (1998), pp. 351-379
  20. Liang, G., Mudawar, I., Review Of Drop Impact On Heated Walls, Int. J. Heat Mass Transf., 106 (2017), pp. 103-126
  21. Cheng, W., et al., Theoretical Investigation On The Mechanism Of Surface Temperature Non-Uniformity Formation In Spray Cooling, Int. J. Heat Mass Transf., 55 (2012), 19-20, pp. 5357-5366
  22. Hsieh, S.S., et al., Spray Cooling Characteristics Of Water And R-134a. Part I: Nucleate Boiling, Int. J. Heat Mass Transf., 47 (2004), 26, pp. 5703-5712
  23. Mudawar, I., Valentine, W.S., Determination Of The Local Quench Curve For Spray-Cooled Metallic Surfaces, J. Heat Treat., 7 (1989), 2, pp. 107-121
  24. Hsieh, S.S., et al., Spray Cooling Characteristics Of Water And R-134a. Part II: Transient Cooling, Int. J. Heat Mass Transf., 47 (2004), 26, pp. 5713-5724
PDF VERSION [DOWNLOAD]
Heat transfer in a novel microwave heating device coupled with atomization feeding

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence