مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

مطالعه عددی و تجربی پارامترهای موثر بر کارآیی حرارتی لوله‌های گرمایی دایروی مستقیم دو سر خنک‌شونده با تبخیرکننده میانی

نوع مقاله : پژوهشی اصیل

نویسندگان
دانشکده مهندسی مکانیک، دانشگاه کاشان، کاشان، ایران
چکیده
لوله گرمایی وسیله‌ای کارآمد در انتقال حرارت است و می‌تواند مقادیر بزرگی از گرما را با اختلاف دمای اندک بین منبع گرم و سرد به سرعت انتقال دهد. در مطالعه حاضر از یک روش شبیه‌سازی عددی دوبعدی برای تحلیل کارآیی حرارتی لوله‌های گرمایی دو سر خنک‌شونده با تبخیرکننده میانی و بررسی تاثیر شرایط عملکرد، مشخصات فتیله و محفظه نگه‌دارنده روی آن استفاده شد. معادلات حاکم توسط نرم‌افزار انسیس فلوئنت گسسته‌سازی شده و سپس با استفاده از شرایط مرزی مناسب حل و پروفیل دمای دیواره لوله گرمایی به‌دست آورده شد. سپس برای اعتبارسنجی نتایج و همچنین بررسی اثر استفاده از دو چگالنده روی مقاومت حرارتی لوله‌های گرمایی از یک مجموعه آزمایشگاهی استفاده شد. نتایج حل عددی با نتایج تجربی و عددی معتبر مورد مقایسه قرار گرفت که دارای تطابق بسیار خوب و قابل قبولی بود. نتایج نشان داد که لوله‌های گرمایی دو سر خنک‌شونده نسبت به لوله‌های گرمایی معمولی مقاومت حرارتی کمتری داشتند. مقدار مقاومت حرارتی با افزایش میزان ضخامت و تخلخل فتیله افزایش پیدا می‌کرد. اما افزایش طول تبخیرکننده و چگالنده‌ها و همچنین افزایش ضخامت و قطر داخلی محفظه نگه‌دارنده موجب کاهش مقاومت حرارتی می‌شد. همچنین نتایج نشان داد که لوله‌های گرمایی که در ساخت محفظه نگه‌دارنده و فتیله آنها از موادی با ضریب هدایت حرارتی بالاتری استفاده شده بود مقاومت حرارتی کمتری داشتند. در نهایت مشخص شد که میزان افزایش توان حرارتی روی مقاومت حرارتی تاثیر قابل توجهی نداشت.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

Numerical and Experimental Study of the Effective Parameters on the Thermal Performance of Straight Circular Heat Pipes with Double-Ended Cooling with Middle Evaporator

نویسندگان English

B. Habibnezhad Ledari
M. sabzpooshani
Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran
چکیده English

The heat pipe is an efficient heat transfer device and can transfer large amounts of heat with a small temperature difference between the hot and cold sources quickly. In the present study, a two-dimensional numerical simulation method was used to analyze the thermal performance of heat pipes with double-ended cooling with the middle evaporator and to investigate the effect of operating conditions, wick and retaining chamber characteristics on it. The governing equations were discretized by ANSYS Fluent software and then solved using suitable boundary conditions. The wall temperature profile of the heat pipe was obtained. Then, to validate the results and to investigate the effect of using two condensers on the thermal resistance of the heat pipes, an experimental apparatus was used. Numerical results were compared with the valid numerical and experimental results that had very good and acceptable accordance. The results showed that the heat pipes with double-ended cooling with a middle evaporator had a lower thermal resistance than conventional heat pipes. The amount of thermal resistance increased with increasing the thickness and porosity of the wick. However, increasing the evaporators and condensers length, as well as increasing the thickness and internal diameter of the retaining chamber, reduced the thermal resistance. The results also showed that the heat pipes, which the materials with higher thermal conductivity were used in their wick and retaining chamber's manufacturing, had a lower thermal resistance. Finally, it was found that the increase of thermal power had no significant effect on the thermal resistance.

کلیدواژه‌ها English

Straight Heat Pipe
Effective Parameters
Thermal Performance
Double-Ended Cooling
Middle-Evaporator
Sun X, Ling L, Liao S, Chu Y, Fan S, Mo Y. A thermoelectric cooler coupled with a gravity-assisted heat pipe: An analysis from heat pipe perspective. Energy Conversion and Management. 2018;155:230-242. [Link] [DOI:10.1016/j.enconman.2017.10.068]
Kim TY, Hyun BS, Lee JJ, Rhee J. Numerical study of the spacecraft thermal control hardware combining solid-liquid phase change material and a heat pipe. Aerospace Science and Technology. 2013;27(1):10-16. [Link] [DOI:10.1016/j.ast.2012.05.007]
Tiari S, Qiu S, Mahdavi M. Discharging process of a finned heat pipe-assisted thermal energy storage system with high temperature phase change material. Energy Conversion and Management. 2016;118:426-437. [Link] [DOI:10.1016/j.enconman.2016.04.025]
Sharifi N, Faghri A, Bergman TL, Andraka CE. Simulation of heat pipe-assisted latent heat thermal energy storage with simultaneous charging and discharging. International Journal of Heat and Mass Transfer. 2015;80:170-179. [Link] [DOI:10.1016/j.ijheatmasstransfer.2014.09.013]
Iranmanesh M, Barghi Jahromi MS. Effect of forced convection and PCM materials on an indirect solar dryer equipped with evacuated heat pipe collector. Modares Mechanical Engineering. 2019;19(11):2607-2614. [Link]
Xu Z, Zhang Y, Li B, Wang CC, Li Y. The influences of the inclination angle and evaporator wettability on the heat performance of a thermosyphon by simulation and experiment. International Journal of Heat and Mass Transfer. 2018;116:675-684. [Link] [DOI:10.1016/j.ijheatmasstransfer.2017.09.028]
Mahdavi M, Tiari S, De Schampheleire S, Qiu S. Experimental study of the thermal characteristics of a heat pipe. Experimental Thermal and Fluid Science. 2018;93:292-304. [Link] [DOI:10.1016/j.expthermflusci.2018.01.003]
Abdulshaheed AA, Wang P, Huang G, Li C. High performance copper-water heat pipes with nanoengineered evaporator sections. International Journal of Heat and Mass Transfer. 2019;133:474-486. [Link] [DOI:10.1016/j.ijheatmasstransfer.2018.12.114]
Shojaeefard MH, Khalkhali A, Zare J, Tahani M. Multi objective optimization of heat pipe thermal performance while using aluminium oxide nanofluid. Modares Mechanical Engineering. 2014;14(1):158-167. [Link]
Faghri A. Analysis of frozen startup of high-temperature heat pipes and three-dimensional modeling of block-heated heat pipes. [Report]. Dayton: Wright State University;1991. [Link]
Franchi G, Huang X. Development of composite wicks for heat pipe performance enhancement. Heat Transfer Engineering. 2008;29(10):873-884. [Link] [DOI:10.1080/01457630802125740]
Chen MM, Faghri A. An analysis of the vapor flow and the heat conduction through the liquid-wick and pipe wall in a heat pipe with single or multiple heat sources. International Journal of Heat and Mass Transfer. 1990;33(9):1945-1955. [Link] [DOI:10.1016/0017-9310(90)90226-K]
Famouri M, Abdollahzadeh MM, Abdulshaheed A, Huang G, Carbajal G, Li C. Transient analysis of a cylindrical heat pipe considering different wick structures. ASME 2016 Heat Transfer Summer Conference, July 10-14, 2016, Washington, DC, USA. New York: ASME; 2016. [Link] [DOI:10.1115/HT2016-7469]
Do KH, Kim SJ, Garimella SV. A mathematical model for analyzing the thermal characteristics of a flat micro heat pipe with a grooved wick. International Journal of Heat and Mass Transfer. 2008;51(19-20):4637-4650. [Link] [DOI:10.1016/j.ijheatmasstransfer.2008.02.039]
Tournier JM, El-Genk M. A heat pipe transient analysis model. International Journal of Heat and Mass Transfer. 1994;37(5):753-762. [Link] [DOI:10.1016/0017-9310(94)90113-9]
Nouri-Borujerdi A, Layeghi M. A numerical analysis of vapor flow in concentric annular heat pipes. Journal of Fluids Engineering. 2004;126(3):442-448. [Link] [DOI:10.1115/1.1760549]
Brahim TIE, Jemni A. Heat pipe simulation under critical conditions. Frontiers in Heat Pipes (FHP). 2012;3(3). [Link] [DOI:10.5098/fhp.v3.3.3003]
Zhu N, Vafai K. Vapor and liquid flow in an asymmetrical flat plate heat pipe: A three-dimensional analytical and numerical investigation. International Journal of Heat and Mass Transfer. 1998;41(1):159-174. [Link] [DOI:10.1016/S0017-9310(97)00075-6]
Zhu N, Vafai K. Analysis of cylindrical heat pipes incorporating the effects of liquid-vapor coupling and non-Darcian transport-a closed form solution. International Journal of Heat and Mass Transfer. 1999;42(18):3405-3418. [Link] [DOI:10.1016/S0017-9310(99)00017-4]
Pooyoo N, Kumar S, Charoensuk J, Suksangpanomrung A. Numerical simulation of cylindrical heat pipe considering non-Darcian transport for liquid flow inside wick and mass flow rate at liquid-vapor interface. International Journal of Heat and Mass Transfer. 2014;70:965-978. [Link] [DOI:10.1016/j.ijheatmasstransfer.2013.11.023]
Mahjoub S, Mahtabroshan A. Numerical Simulation of a conventional heat pipe. World Academy of Science, Engineering and Technology. 2008;2(3):265-270. [Link]
Ahmed NZ, Singh PK, Janajreh I, Shatilla Y. Simulation of flow inside heat pipe: Sensitivity study, conditions and configuration. ASME 2011 5th International Conference on Energy Sustainability, August 7-10, 2011, Washington, DC, USA. New York: ASME; 2012. [Link] [DOI:10.1115/ES2011-54295]
Hussain MN, Janajreh I. Numerical simulation of a cylindrical heat pipe and performance study. International Journal of Thermal & Environmental Engineering. 2016;12(2):135-141. [Link]
Mahdavi M, Tiari S, Solanki A, Pawar V. Numerical study on the performance characteristics of cylindrical heat pipes with differing wick type. ASME 2018 International Mechanical Engineering Congress and Exposition, November 9-15, 2018, Pittsburgh, Pennsylvania, USA. New York: ASME; 2019. [Link] [DOI:10.1115/IMECE2018-86607]
Habibnezhad Ledari B, Sabzpooshani M. Experimental investigation on the thermal resistance of straight heat pipes with double-ended cooling and middle-heating at different tilt angles. Amirkabir Journal of Mechanical Engineering. 2019 Jul. [Link]
Chi SW. Heat pipe theory and practice [Report]. Washington, DC, Hemisphere Publishing Corp; 1976. [Link]
Kumaresan G, Venkatachalapathy S, Asirvatham LG. Experimental investigation on enhancement in thermal characteristics of sintered wick heat pipe using CuO nanofluids. International Journal of Heat and Mass Transfer. 2014;72:507-516. [Link] [DOI:10.1016/j.ijheatmasstransfer.2014.01.029]
Yousefi T, Mousavi SA, Farahbakhsh B, Saghir MZ. Experimental investigation on the performance of CPU coolers: Effect of heat pipe inclination angle and the use of nanofluids. Microelectronics Reliability. 2013;53(12):1954-1961. [Link] [DOI:10.1016/j.microrel.2013.06.012]
Tang H, Tang Y, Zhuang B, Chen G, Zhang S. Experimental investigation of the thermal performance of heat pipes with double-ended heating and middle-cooling. Energy Conversion and Management. 2017;148:1332-1345. [Link] [DOI:10.1016/j.enconman.2017.07.002]