Simulation and Thermodynamic Analysis of a Closed Cycle Nitrogen Expansion Process for Liquefaction of Natural Gas in Mini-scale

Document Type : Original Article


1 Institute of Liquefied Natural Gas (ILNG), School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran

2 Professor, Institute of Liquefied Natural Gas (I-LNG), School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran

3 Research & Technology Directorate of National Iranian Gas Company

4 Assistant Professor, Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran


In this study a closed nitrogen expansion cycle (Niche) has been simulated with Aspen HYSYS V8.4. Energy and exergy analysis were applied to evaluate the process. Results of energy analysis indicated that specific power consumption of this process is 0.68 kWh/kg LNG. The results of exergy analysis showed that exergy efficiency of Niche LNG is 35.51%. It is concluded there is an interaction between specific power consumption and exergetic efficiency. Moreover, the highest value of exergetic efficiency and irrevsibility belong to compressor (C3) and gas turbine (E1). Moreover, this process can be suitable for mini-scale LNG plants.


Main Subjects

Article Title [Persian]

شبیه‌سازی و تحلیل ترمودینامیکی فرآیند انبساطی نیتروژن چرخه بسته برای مایع‌سازی گاز طبیعی در مقیاس کوچک

Authors [Persian]

  • امیرحسین یزدانی‌نیا 1
  • علی وطنی 2
  • مرضیه زارع 3
  • مژگان عباسی 4

1 انستیتو گاز طبیعی مایع (ILNG)، گروه مهندسی شیمی، دانشکده فنی، دانشگاه تهران، تهران، ایران

2 پروفسور، انستیتو گاز طبیعی مایع (I-LNG)، دانشکده مهندسی شیمی، دانشکده فنی، دانشگاه تهران، تهران، ایران

3 مدیریت پژوهش و فناوری شرکت ملی گاز ایران، تهران، ایران

4 استادیار، دانشکده مهندسی شیمی، انستیتو مهندسی نفت (IPE)، دانشکده فنی، دانشگاه تهران، تهران، ایران

Abstract [Persian]

در این پژوهش، یک چرخه انبساطی نیتروژن بسته (Niche) با استفاده از نرم‌­افزار Aspen HYSYS V8.4 شبیه‌­سازی گردیده است. به­منظور ارزیابی فرآیند مذکور از تحلیل­های انرژی و اکسرژی استفاده شده است. نتایج حاصل از تحلیل انرژی نشان داد که میزان توان ویژه مصرفی این فرآیند برابر kWh/kg LNG ۰/۶۸ می­باشد. نتایج حاصل از تحلیل اکسرژی نیز نشان داد که راندمان اکسرژی فرآیند Niche LNG برابر %51/35 است. نتیجه حاصل از این دو تحلیل تعامل بین توان ویژه مصرفی و راندمان اکسرژی بود. علاوه بر این، بالاترین مقدار راندمان و اتلاف اکسرژی، به­ترتیب متعلق به کمپرسور C3 و توربین گازی E1 است. همچنین می­توان گفت این فرآیند برای واحدهای مقیاس کوچک LNG می­تواند گزینه مناسبی است.

Keywords [Persian]

  • چرخه انبساطی نیتروژن بسته
  • تحلیل اکسرژی
  • توان ویژه مصرفی
  • گاز طبیعی مایع (LNG
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