مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

بهینه‌سازی ابعاد هندسی فایرتیوب و هیت‌کویل گرمکن‌های ایستگاه‌های تقلیل فشار گاز

نوع مقاله : پژوهشی اصیل

نویسندگان
1 گروه مهندسی مکانیک، پردیس خوارزمی، دانشگاه صنعتی شاهرود، شاهرود، ایران
2 گروه مهندسی مکانیک، دانشکده مهندسی، دانشگاه فردوسی مشهد، مشهد، ایران
چکیده
گاز طبیعی پر‌فشار خطوط انتقال پیش از ورود به شیر اختناق ایستگاه‌های دروازه شهری (CGS)، از گرمکن‌هایی عبور داده می‌شود که دمای آن را تا حد جبران اُفت دمای ناشی از اثر ژول- تامسون افزایش دهد و از بروز پدیده هیدراته‌شدن گاز، یخ‌زدگی شیر و انسداد مسیر عبور گاز جلوگیری می‌نمایند. بهینه‌سازی این گرمکن‌ها با توجه به این که در مقیاس وسیع از گاز فرآوری‌شده شبکه تغذیه می‌کنند، از اهمیت بسزایی برخوردار است. در مطالعه حاضر هر یک از این گرمکن‌ها به‌نوعی ماشین ترمودینامیک مرکب از دو سیستم حرارتی متمایز از هم شبیه‌سازی شده است. تحلیل ترمودینامیک این دو سیستم با توجه به هندسه مساله و معادلات حاکم، به فرمولاسیون رابطه بین بازده ‌حرارتی آنها و سپس تعریف پارامتری موسوم به ضریب‌ تشابه‌ ترمودینامیک انجامید. آنگاه نتایج حاصل از تحلیل‌ حرارتی و تقریب‌زدن تابع پیچیده اصلی با دو تابع ساده‌تر مشخص نمود که همواره بین تفاضل مقادیر تعداد واحدهای تبادل حرارت‌ (NTU) فایرتیوب و هیت‌کویل با ضریب‌ تشابه‌ ترمودینامیک گرمکن‌ها، رابطه لگاریتمی‌ ثابت و بین نسبت مقادیر NTU آن دو با این ضریب نیز رابطه توانی ثابتی برقرار است. سرانجام با حل دستگاه‌ معادلات به‌دست‌آمده از این دو رابطه، امکان تعیین مقادیر بهینه NTU برای فایرتیوب و هیت‌کویل به‌صورت توابعی از ضریب‌ تشابه‌ ترمودینامیک بهینه گرمکن‌ها و به‌تبع آن دستیابی به رابطه بین ابعاد هندسی بهینه آن دو در ایده‌آل‌ترین وضعیت انتقال حرارت، با بیشینه خطای نسبی حدود ۱۳% فراهم شد.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

Optimization of Geometric Dimensions of Fire Tube and Heat Coil Used in City Gate Stations Heaters

نویسندگان English

S.R. Kazemi Mazandarani 1
M. Farzaneh-Gord 2
M.M. Shahmardan 1
1 Mechanical Engineering Department, Kharazmi Campus, Shahrood University of Technology, Shahrood, Iran
2 Mechanical Engineering Department, Engineering Faculty, Ferdowsi University of Mashhad, Mashhad, Iran
چکیده English

Prior to entering to the throttling valve of the City Gate Stations (CGS), high-pressure natural gas flow in pipelines is transmitted through Water Bath Indirect Heaters (WBIH), which is increasing its temperature to compensate for the temperature drop caused by the Joule-Thomson effect and preventing the occurrence of the hydration phenomenon, gas freezing, and subsequent blockage of the gas flow path. Because of feeding of processed gas of the network on a large scale, optimizing the WBIHs has a lot of significance. In the present study, each WBIH is simulated by a type of thermodynamic machine, consisting of two distinct thermal systems. According to the problem geometry and governing equations, the thermodynamic analysis of these two systems results in the formulation of a relationship between their thermal efficiencies together and the definition of a parameter was defined as the Thermodynamic Similarity Coefficient (TSC). Then, the results showed that always, a constant logarithmic relationship exists between of the Number of Heat Transfer Units (NTU) values difference of the fire tube and heat coil of the WBIHs with their TSC as well as a constant power relationship between their NTU values ratio with this coefficient too. Finally, by solving the equation system obtained from these two relations, it was possible to determine the optimal values of NTU for the fire tube and heat coil as functions of TSC of the WBIH and to achieve the relationship between their optimum geometric dimensions together in the most ideal heat transfer state with a maximum relative error of about 13%.

کلیدواژه‌ها English

Optimization
simulation
thermal efficiency
Exergy efficiency
Entropy Generation
Machin Sazi Arak, Knowledge-Based Company. MSA Oil, Gas & Petrochemical Equipment. [Internet]. Arak: MSA; 2018 [cited 2018 Mar 17]. Available from: http://www.msa.ir/index.aspx?fkeyid=&siteid=3&pageid=257 [Link]
Ghaebi H, Farhang B, Rostamzadeh H, Parikhani T. Energy, exergy, economic and environmental (4E) analysis of using city gate station (CGS) heater waste for power and hydrogen production: A comparative study. International Journal of Hydrogen Energy. 2018;43(3):1855-1874. [Link] [DOI:10.1016/j.ijhydene.2017.11.093]
Zabihi A, Taghizadeh M. New energy-saving temperature controller for heater at natural gas gate station. Journal of Natural Gas Science and Engineering. 2015;27(Part 2):1043-1049. [Link] [DOI:10.1016/j.jngse.2015.09.046]
Farzaneh-Gord M, Arabkoohsar A, Deymi Dasht-bayaz M, Farzaneh-Kord V. Feasibility of accompanying uncontrolled linear heater with solar system in natural gas pressure drop stations. Energy. 2012;41(1):420-428. [Link] [DOI:10.1016/j.energy.2012.02.058]
Farzaneh-Gord M, Arabkoohsar A, Deymi Dasht-bayaz M, Machado L, Koury RNN. Energy and exergy analysis of natural gas pressure reduction points equipped with solar heat and controllable heaters. Renewable Energy. 2014;72:258-270. [Link] [DOI:10.1016/j.renene.2014.07.019]
Hoseinipanah R, Nikdel S. Replacement of shell and tube heat exchangers with conventional heaters used in the gas pressure reduction city gate stations. The 6th National Heat Exchanger Conference, 20 November, 2014, Tehran, Iran. Tehran: Civilica; 2014. [Persian] [Link]
Sabermoghaddam A, Farhadiyan N, Sheikhiyani H. Feasibility of energy optimization in the heaters of the gas pressure reduction station. The 5th National Conference on CFD Applications in the Chemical and Petroleum Industries, 21 May, 2014, Tehran, Iran. Tehran: Iran University of Science and Technology; 2014. [Link]
Azizi SH, Rashidmardani A, Andalibi MR. Study of preheating natural gas in gas pressure reduction station by the flue gas of indirect water bath heater. International Journal of Science and Engineering Investigations. 2014;3(27):17-22. [Link]
Ashouri E, Veysi F, Shojaeizadeh E, Asadi M. The minimum gas temperature at the inlet of regulators in natural gas pressure reduction stations (CGS) for energy saving in water bath heaters. Journal of Natural Gas Science and Engineering. 2014;21:230-240. [Link] [DOI:10.1016/j.jngse.2014.08.005]
Sanaye S, Mohammadi Nasab A. Modeling and optimizing a CHP system for natural gas pressure reduction plant. Energy. 2012;40(1):358-369. [Link] [DOI:10.1016/j.energy.2012.01.060]
Khalili E, Hoseinalipour SM, Heybatian E. Efficiency and heat losses of indirect water bath heater installed in natural gas pressure reduction station; evaluating a case study in Iran. The 8th National Energy Congress, 24 May-25 June, 2011, Tehran, Iran. Tehran: National Energy Committee of the Islamic Republic of Iran; 2011. [Link]
Sadoddin S, Rastegar S. Exergy analysis in city gate stations used for reducing natural gas pressure. Journal of Modeling in Engineering. 2010;8(22):13-20. [Persian] [Link]
Dincer I, Rosen MA. Exergy: Energy, environment and sustainable development. 2nd Edition. New York: Elsevier; 2012. pp. 31-32. [Link]
Bejan A. Entropy generation minimization: The method of thermodynamic optimization of finite-size systems and finite-time processes. 1st Edition. Boca Raton: CRC press; 1995. pp. 21-23 [Link]
Kays WM, Crawford ME. Convective heat and mass transfer. 3rd Edition. New York: McGraw-Hill Education; 1993. pp. 333-335. [Link]
Winterbone D, Turan A. Advanced thermodynamics for engineers. 2nd Edition. Oxford: Butterworth-Heinemann; 1996. pp. 34-39. [Link]
Wall G. Exergetics. Bucaramanga: Exergy Ecology Democracy; 2009. pp. 58-61. [Link]
Çengel YA, Boles MA. Thermodynamics: An engineering approach. 8th Edition. New York: McGraw-Hill Education; 2014. pp. 780-781. [Link]
Turns SR. An introduction to combustion: Concepts and applications. 2nd Edition. New York: McGraw-Hill Education; 2000. p. 649. [Link]
Bejan A. Advanced engineering thermodynamics. 4th Edition. Hoboken: John Wiley & Sons; 2016. pp. 18-20. [Link] [DOI:10.1002/9781119245964]
Incropera FP, DeWitt DP. Introduction to heat transfer. 6th Edition. Hoboken: Wiley; 2011. [Link]
Sauer T. Numerical analysis. 2nd Edition. London: Pearson College Division; 2012. [Link]
Systat Software Incorporated. SigmaPlot, Exact Graphs and Data Analysis [Internet]. Chicago: SSI; 2018 [cited 2018 Mar 17]. Available from: http://www.sigmaplot.co.uk/products/sigmaplot/sigmaplot-details [Link]
Shah RK, Sekulic DP. Fundamentals of heat exchanger design. 2nd Edition. Hoboken: John Wiley & Sons; 2003. pp. 120-125. [Link] [DOI:10.1002/9780470172605]
Lestina T, Serth RW. Process heat transfer: Principles, applications and rules of thumb. New York: Elsevier; 2007. [Link]
Bejan A. Convection heat transfer. 4th Edition. Hoboken: John Wiley & Sons; 2013. pp. 19-23. [Link] [DOI:10.1002/9781118671627]
Kakaç S, Liu H, Pramuanjaroenkij A. Heat exchangers: Selection, rating, and thermal design. 3rd Edition. Boca Raton: CRC Press; 2012. pp. 59-63. [Link] [DOI:10.1201/b11784]