List of Articles مبدل حرارتی

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  1 - Investigating the effective parameters and various methods of computing the borehole depth of vertical ground heat exchanger of geothermal heat pump
  Setareh Mehrkhou
  In geothermal heat pumps, the heat exchange with ground is performed by the ground heat exchanger. In fact, the ground heat exchanger is installed to extract or inject the thermal energy from/to the earth. The borehole depth of this heat exchanger has a major effect on More

  In geothermal heat pumps, the heat exchange with ground is performed by the ground heat exchanger. In fact, the ground heat exchanger is installed to extract or inject the thermal energy from/to the earth. The borehole depth of this heat exchanger has a major effect on the system investment cost and operation; thus, this parameter must be computed with a high accuracy. There are various methods to compute the borehole depth of ground heat exchanger. The geothermal heat pump capacity and the regional soil characteristics are the main parameters which affect the borehole depth and size of the ground heat exchanger. In this paper, the important soil characteristics are first introduced. Then, the main five methods for computing the borehole depth of ground heat exchanger are investigated with their effective parameters. Finally, these methods are compared and their application priority is determined. Manuscript profile
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  2 - Study of Heat Transfer and Exergy Analysis in Double-tubed Heat Exchangers Equipped with Turbulenter Using Nanofluid TiO2
  S.M. Hosseini M. Mohammadiun S. Mortazavi
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  3 - Improving the efficiency of Triplex heat exchanger using Phase Change Materials
  Abbas kosarineia Amin Ziaeifar
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  4 - Numerical and Annalytical Review on earth to air heat exchanger and Exergoeconomic Analysis
  Saeed Asadi Ahad Abedini
  In recent years, especially the last three decades, many studies have been done on earth to air heat exchangers or air underground pipes worldwide by researchers and professors.In this article we have tried to work with the most important markets in the past three analy More

  In recent years, especially the last three decades, many studies have been done on earth to air heat exchangers or air underground pipes worldwide by researchers and professors.In this article we have tried to work with the most important markets in the past three analytical, numerical and exergoeconomic and offering them all at once and researchers interested in the subject or those who want to be familiar with the exchangers. Appropriate references to specialized and more complete study, to be collected. Research in this field of activity and a change in attitude on energy consumption and consequently reduce pollutants, as well as saving the economy Manuscript profile
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  5 - Numerical Study of Cooling Buildings with Cylindrical Roof Using Surface-to-AirHeat Exchanger
  Saeed Asadi Ahad Abedini
  In this study, a hybrid cooling system, including ground-to-air heat exchanger and a cylindrical roof is studied. In the proposed system, the ground-to-air heat exchanger cooling system passive system and cylindrical roof as natural ventilation, to achieve thermal comfo More

  In this study, a hybrid cooling system, including ground-to-air heat exchanger and a cylindrical roof is studied. In the proposed system, the ground-to-air heat exchanger cooling system passive system and cylindrical roof as natural ventilation, to achieve thermal comfort conditions and also supplies the required cooling load of the building in the city of Semnan have been used.The outside air is then passed over the roof, increasing speed and reducing pressure leads to indoor air is evacuated where the relative vacuum in the room leads to cool air in underground channels conducted into the building. Simulation of three-dimensional air flow in the heat exchanger surface-to-air, cylindrical roof and the room was solved by Fluent software. For this building and the heat exchanger in a channel with dimensions 120 × 40 × 40 meters have been placed as computing space. The data, ground-to-air outlet temperature of the heat exchanger was calculated numerically with MATLAB computer code and finally the temperature was brought to the room. The results show that the system with 2 tube dr = 0.082 for the space Lr = 7.14 can be abstain comfort condition in Semnan. Also according to the results, opening for the roof span is Ar = 0.082. In this study, the effect of different factors such as wind speed, average room temperature, the aperture diameter of roof, diameter, length and number of tubes ground-to-air heat exchanger was investigated. Manuscript profile
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  6 - Heat Transfer Simulation in the Heat Exchanger U-Tube
  فرامرز ملکی مقدم احد عابدینی
  Heat transfer used is one of the most important and applicable natural phenomenon. Heat exchangers are the must applicable member in the chemical process and we can consider them in lots of industrial units. That provided the hat energy transfer between two or several f More

  Heat transfer used is one of the most important and applicable natural phenomenon. Heat exchangers are the must applicable member in the chemical process and we can consider them in lots of industrial units. That provided the hat energy transfer between two or several fluid with different temperature. This operation can be done between liquid – liquid, gas - gas and gas - liquid. Heat exchanger will be used in order to cooling hot fluid and heating fluid with lower temperature or both of them. Many industries are acting in design kind of heat exchanger and many field with difference names in heat exchangers design are submitted by college and university. In this dissertation, heat transfer of heat exchanger shell and tube is simulated that it is U figure and the geometric of heat exchanger has been plotted and are meshed in GAMBIT software then are analyze in ANSYS FLUENT software. Finally the obtained answers are compare with designer is answers that have obtained in ASPEN software. The flow kind has been three-dimensional and turbulence that it has been used of turbulence model kω-sst. That should be noted the heat exchanger has been simulated by single phase. Manuscript profile
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  7 - performance enhancement of a two-fluid corrugated torsional heat exchanger containing hybrid nanofluids
  mojtaba jamiati Hossein Pourmohamadian
  In this research, the effect of the corrugate inside a two-fluid torsional heat exchanger containing a hybrid water-copper-carbon nanotube nanofluid is investigated numerically using computational fluid dynamics. The geometry of the torsion heat exchanger is prepared us More

  In this research, the effect of the corrugate inside a two-fluid torsional heat exchanger containing a hybrid water-copper-carbon nanotube nanofluid is investigated numerically using computational fluid dynamics. The geometry of the torsion heat exchanger is prepared using Design Modler software. Also, in order to analyze the fluids, the finite volume method and Ensys Fluent software are used. The hybrid nanofluid stream is in the turbulent and the K Omega turbulence model is used to model it. The geometry of the simple torsional heat exchanger is compared with the torsional heat exchanger with the corrugate and the output results are presented in the form of graphs of mean Nusselt number, pressure drop and PEC index. The study is performed for Reynolds numbers 6000 to 24000, volume fraction of 1 to 5% and three different heights of 1, 2 and 3 mm from the congress. The results obtained from numerical simulation show that the use of water-copper-carbon nanotube hybrid nanofluid causes higher thermal performance than water-based fluid. Manuscript profile
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  8 - پژوهش تجربی بهبود انتقال انرژی گرمایی در اثر تعلیق نانو ذرات داخل سیال عامل انتقال گرما
  ارش کریم پور داود طغرایی امید علی اکبری مجید زرین قلم غلامرضا احمدی شیخ شبانی
  در کاربردهای مهندسی انتقال حرارت سیالات از اهمیت ویژه‌ای برخوردار است، بنابراین مهندسان و پژوهشگران، روش‌های متعددی را به منظور افزایش انتقال حرارت پیشنهاد کردند. در سال‌های اخیر روش‌های نوینی به کار گرفته شده ‌است. یکی از این روش‌ها استفاده ازنانو‌سیالات است. نانو‌سیال More

  در کاربردهای مهندسی انتقال حرارت سیالات از اهمیت ویژه‌ای برخوردار است، بنابراین مهندسان و پژوهشگران، روش‌های متعددی را به منظور افزایش انتقال حرارت پیشنهاد کردند. در سال‌های اخیر روش‌های نوینی به کار گرفته شده ‌است. یکی از این روش‌ها استفاده ازنانو‌سیالات است. نانو‌سیالات دارای خواص گرمایی مطلوبی نسبت به سیال پایه می‌باشند. در این تحقیق تاثیر تعلیق نانوذرات اکسید مس داخل سیال عامل آب با کسر حجمی 005/0(5/0%)، تحت رژیم جریان مغشوش در داخل مبدل حرارتی دو لوله‌ای جریان مخالف مورد بررسی قرار می‌گیرد و مشاهده می‌شود که تعلیق این میزان از نانو ذرات اکسید مس در داخل سیال پایه آب، منجر به بهبود قابلیت انتقال انرژی گرمایی این سیال عامل از سیستم می‌گردد. همچنین از سوی دیگر؛ تعلیق نانو ذرات منجر به افزایش افت فشار و ضریب اصطکاک سیال پایه نیز می گردند، اما محاسبات انجام شده نشان می‌دهند که تاثیرات مثبت استفاده از این میزان نانو ذرات معلق در آب بر بهبود انتقال گرما از سیستم؛ نسبت به تاثیرات منفی آنها بر افزایش افت فشار و ضریب اصطکاک غلبه می‌کند که این نتایج، محققان را به سوی استفاده از این نانو سیال به عنوان سیال عامل در کاربردهای عملی رهنمون می‌سازد. Manuscript profile