تحلیل و بهینه‌یابی یک مبدل حرارتی جهت کاربرد در سامانه خروج دود موتور دیزل

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشیار دانشگاه صنعتی مالک اشتر، تهران، ایران

2 استادیار، دانشگاه صنعتی مالک اشتر، تهران، ایران

3 دانشیار، دانشگاه صنعتی مالک اشتر، تهران، ایران

چکیده

در پژوهش حاضر به تحلیل و بهینه‌یابی یک مبدل حرارتی استفاده شده در سامانه خروج دود موتور دیزل پرداخته شده است. هدف عمده استفاده از این مبدل، کاهش دمای محصولات احتراق خروجی از موتور می‌باشد. این امر با قرار دادن یک مبدل حرارتی در مسیر خروجی دود موتور انجام خواهد گرفت. جهت تحلیل مساله چند طرح مختلف از انواع مبدل‌های حرارتی ارائه گردیده است. مبدل‌های حرارتی سه و پنج لوله‌ای با افزایش سطح تماس میان دود و آب خنک‌کن، دمای دود را تا حد قابل قبولی کاهش می‌دهند، اما افت فشار ایجاد شده در سمت دود در این طرح‌ها زیاد است. استفاده از پره‌های حلقوی و پره‌های طولی در مبدل حرارتی در سمت دود، با افزایش سطح تماس میان جریان دود و آب و افزایش اغتشاش در مسیر دود، منجر به افزایش تبادل حرارت می‌شود. در این طرح‌ها دمای خروجی مبدل حرارتی بیش از مقدار مجاز ( 350) بوده و افت فشار ایجاد شده در آنها نیز قابل توجه است. پس از بررسی طرح‌های پیشنهاد شده جهت کاهش دمای دود، مبدل‌های حرارتی پوسته و لوله به‌عنوان طرح‌های نهایی این پژوهش انتخاب شدند. بررسی‌ها نشان داد که مبدل حرارتی پوسته و لوله قادر به کاهش دمای دود خروجی تا مقدار 309/42 است.

کلیدواژه‌ها


عنوان مقاله [English]

Analysis and finding optimal values of a heat exchanger for using in diesel engine exhaust system

نویسندگان [English]

  • jamasb pirkandi 1
  • Mahdi Hashemabadi 2
  • Mostafa Mahmoodi 3
1 Associate Professor Malek Ashtar University of Technology, Tehran, Iran
2 Assistant Professor, Malek Ashtar University of Technology, Tehran, Iran
3 Associate Professor, Malek Ashtar University of Technology, Tehran, Iran
چکیده [English]

In the presented research, the analysis and finding optimal values of a heat exchanger used in the exhaust system of a diesel engine has been discussed. The main purpose of using this heat exchanger is to reduce the temperature of combustion products exhausting from the engine. This can be done by mounting a heat exchanger at the exhaust gas path. In order to analyze the issue, different designs of heat exchangers have been regarded. Three- and five-tube heat exchangers reduce the temperature of the smoke to an acceptable level by increasing the contact surface between the smoke and the cooling water. However, the pressure drop created on the side of the smoke is high in these designs. The use of annular fins and longitudinal fins on the smoke side also increase the heat transfer by increasing the contact surface between the smoke and water flow and the turbulence in the smoke path. However, in this design the heat exchanger outlet temperature is higher than allowed value (350 ). Furthermore, in this design, the pressure drop also increases. After the investigations carried out to reduce the temperature of the smoke, shell and tube heat exchangers have been chosen as the final designs. The shell and tube heat exchangers is capable to reduce the exhaust temperature to 309.42 .

کلیدواژه‌ها [English]

  • Annular Tube Heat Exchanger
  • Shell and Tube Heat Exchanger
  • Heat Transfer
  • Turbulent Flow

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