نوع مقاله: مقاله پژوهشی

نویسندگان

1 کارشناسی ارشد گروه مهندسی مکانیک، دانشگاه آزاد اسلامی، واحد نور

2 استادیار گروه مهندسی مکانیک، دانشکده مهندسی، دانشگاه مازنداران

چکیده

برج های خنک کننده تر که بطور وسیعی در صنایع مختلف برای دفع حرارتهای مازاد مورد استفاده قرار می گیرند، دارای معایب و محدودیت هایی هستند. برای این منظور از برج خنک کننده بارشی که در گروه برج خنک کننده تر قرار دارد استفاده می شود .یکی از اشکالات این برج ها استفاده از پکینگ ها است. در این مقاله پس از مرور تحقیقات انجام شده قبلی به بازنویسی معادلات حاکم بر برج ها پرداخته و با استفاده از مدل پیشرفته ریاضی، به منظور شبیه سازی بر اساس قوانین انتقال جرم و انتقال حرارت و معادلات حاکم بر برج خنک کننده بارشی ، رفتار این برج ها مورد بررسی قرار گرفته است. سپس با ارائه یک برنامه کامپیوتری، به حل عددی پرداخته و تاثیر پارامترهای مناسب هندسی و محیطی بررسی شده است. نتایج حاصل با داده های تجربی ارائه شده در تحقیقات دیگر مورد مقایسه قرار گرفته است. با تغییر پارامترهای هندسی (افزایش ارتفاع برج و کاهش قطر قطره) در شرایط محیطی مختلف می توان دمای خروجی از برج خنک کننده بارشی را بهبود بخشید.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Investigation on The effect of geometrical and ambient parameters on the performance of the Counter Flow Shower Cooling Tower

نویسندگان [English]

  • A Asghari 1
  • N Kordani 2

1 Department of Mechanical Engineering, Nour Azad University, Nour, Iran.

چکیده [English]

Wet Cooling towers (WET) that are widely used in different industries and air conditioning systems to remove excessive heat, have disadvantages and limitations. Cooling towers are one of the biggest heat andmass transfer devices that are in wide spreaduse. To overcome these limitations, Counter Flow Shower Cooling Tower (SCT) which is within the Wet Cooling Towers(WCT) category is presented. In this paper, analyzing heat and mass transfer in counter current open cooling towers. Using a computer program, the numerical solution will be executed and the effect of proper environmental and geometrical parameters will be reviewed and compared with experimental results in the recourses. Moreover, the effect of velocity variation, enthalpy, humidity, temperature and droplet diameter on the cooling efficiency of the tower will be investigated. It was concluded that amongst all mentioned parameters, the droplet diameter has the most impact upon decreasing the output temperature of the cooling tower. By changing geometrical parameters(tower height increase and droplet diameter reduction), the outlet temperature of the SCT in different ambient condition could be improved. these towers have high efficiency in dry-cool and dry-hot regions.

کلیدواژه‌ها [English]

  • Shower Cooling Tower (SCT)
  • Mass transfer
  • Heat Transfer
  • Geometric and ambient parameters

1] Dvoršek, M., Hočevar, M., “The Influence of Airflow Inlet Region Modifications on the Local Efficiency of Natural Draft Cooling Tower Operation”, Strojniški Vestnik - Journal of Mechanical Engineering, Vol.57, No.10, p.750-759, 2011.

[2]Walker, W. H., Lewis, W. K., MeAdams, W. H., and Gilliland, E. R., “Principles of Chemical Engineering”, 3rd ed, McGraw-Hill, NewYork, 1923.

[3]Merkel, F., “VerdunstungskfJhlung”, VDI Forschungsarbeiten, No.275, Berlin, 1925.

[4]Baker, D.R., Shryock, H.A., “A Comprehensive Approach to the Analysis of Cooling Tower Performance”, Trans ASME, J Heat Transfer, Vol.83, No.3, pp.339-350, 1961.

[5]Caytan, Y., “Validation of the Two-Dimensional Numerical Model “STAR’ Developed for Cooling Tower Design”, Proc 3rd Cooling, 1982.

[6]Bilal A. Qureshi, and Syed M. Zubair, “Second-Law-based Performance Evaluation of Cooling Towers and Evaporative Heat Exchangers”, International Journal of Thermal Sciences Vol.46, No.2, pp.188-198, 2006.

[7] Givoni, B and Al Hemiddi, N, “Applicability of a Shower”, Passive Cooling Tower in Hot Dry Climate”, 20th National Passive Solar Conference. Minneapolis, Vol.15. pp.143-148, United States, 1995.

[8] Satoshi Y., “Experimental Performance of the Shower Cooling Tower in Japan”, Renewable Energy, Vol.10. No.213, pp.179.-183, 1997

[9] Givoni, B., “Performance of the Shower Cooling Tower in Different Climates”, Renewable Energy., Vol.10, No.23, pp.173-178, 1997.

[10] Qi X., Liu Y., Guo Q., Yu J., Yu S., “Performance Prediction of Seawater Shower Cooling Towers”, Vol.79, pp.435-443, 2016.

[11] Xiaoni, Q., Zhenyan, L. and Dandan, L.  “Performance Charactristics of a Shower Cooling Tower”, Energy Conversion and Management, Vol.40, pp.193-203, 2007.

[12] Gao M., Shi, Y.T., Wang, N.N., Zhao Y.B., and Sun F.Z., “Artificial Neural Network Model Research on Effects of Cross-Wind to Performance Parameters of Wet Cooling Tower based on Level Froude Number”, Applied Thermal Engineering, Vol.51, No.1-2, pp.1226-1234, 2013.

[13] Pan D., Ci Y., He M., and He H., “An Improved Quantum-behaved Particle Swarm Optimization Algorithm Based on Random Weight”, Journal of TWARE, Vol.8, No.6, pp.1327-1332, 2013.

 [14] Muangnoi, T., Asvapoostikul, W. and Hungspreugs, P., “Performance Charactrisics of A Downward Spray Water-Jet Cooling Tower”, Applied Thermal Engineering, Vol.6, 2014.

[15] Qi, X., Liu, Y., Guo Q., Yu S., Yu J. “Performance Prediction of a Shower Cooling Tower using Wavelet Neural Network” ,Applied Thermal Engineering, 2016.

[16] Xiaoni, Q., Yongqi, L. and Zhenyan, L., “Numerical Simulation of Shower Cooling Tower baced on Artificial Network”, Energy Conversion and Management, Vol.49, pp.724-732, 2008.

[17] Qi, X., Liu Z., “Further Investigation on the Performance of a Shower Cooling Tower, Vol.49, pp.570-577, 2008.

[18 ] Johannes, C.K., and Detlev, G.K. “The Lewis Factor and its Influence on the performance Prediction of Wet-cooling Towers”, International Journal of Thermal Sciences, Vol.44, No.9, p.879-884, 2006.

[19] Xiaoni, Q., Zhenyan, L. and Dandan, L., “Perdiction of the Performance of a Shower Cooling Tower baced on Projection Pursuit Regression”, Applied Thermal Engineering, Vol.28, pp.1031-1038, 2008.

[20] Qi, X., Liu, Y., Liu, Z. E, “Exergy Performance Analysis of a Shower Cooling Tower, Journal of Mechanical Engineering”, Vol.59, Vol.4 , pp.251-259, 2013.