Thermal Design Considerations and Performance Evaluation of Cryogenic Tube in Tube Heat Exchangers
نویسندگان
چکیده مقاله:
Heat exchangers are the most important equipment in refrigeration processes. Design and modeling of heat exchangers operating at low temperatures are different from other regular heat exchangers. This study includes two sections. In the first section, design and modeling considerations needed for evaluating the real thermal behavior of heat exchangers at low temperatures were discussed. These considerations are usually neglected by researchers who have modeled the heat exchanger at low temperatures. In the second section, a counter current helically coiled tube in tube heat exchanger operating in hydrogen liquefier was modeled and simulated considering notes discussed in the first section. The model was validated compared with the data presented by literature. The results showed the small positive effect of longitudinal heat conduction on hydrogen liquefaction. The heat in-leak into cold fluid resulted in higher cold fluid outlet temperature and higher hot fluid outlet temperature. Simulations showed that the heat in-leak into cold fluid leads to limit the overdesign for cryogenic heat exchangers. A comparison between models with considering different assumptions was presented and showed that the result may vary significantly based on the regarded assumptions.
منابع مشابه
Effectively Design Shell-and-Tube Heat Exchangers
heat exchangers (STHEs) is done by sophisticated computer software. However, a good understanding of the underlying principles of exchanger design is needed to use this software effectively. This article explains the basics of exchanger thermal design, covering such topics as: STHE components; classification of STHEs according to construction and according to service; data needed for thermal de...
متن کاملThermal Analysis of Shell-and-Tube Thermoacoustic Heat Exchangers
Heat exchangers are of key importance in overall performance and commercialization of thermoacoustic devices. The main goal in designing efficient thermoacoustic heat exchangers (TAHXs) is the achievement of the required heat transfer rate in conjunction with low acoustic energy dissipation. A numerical investigation is performed to examine the effects of geometry on both the viscous and therma...
متن کامل2.5. Preliminary Design of Shell and Tube Heat Exchangers
Second, the exchanger must withstand the service conditions of the plant environment. This includes the mechanical stresses of installation, startup, shutdown, normal operation, emergencies, and maintenance, and the thermal stresses induced by the temperature differences. It must also resist corrosion by the process and service streams (as well as by the environment); this is usually mainly a m...
متن کاملInvestigation of shell and tube heat exchangers by using a design of experiment
Heat exchangers are one of the most important devices of mechanical systems in modernsociety. Most industrial processes involve the transfer of heat and more often they requirethe heat transfer process to be controlled. A heat exchanger is the heat exchanged betweentwo media, one being cold and the other being hot. There are different types of heatexchanger, but the type which is widely used in...
متن کاملInvestigation on Turbulent Nanofluid Flow in Helical Tube in Tube Heat Exchangers
In this study, the thermal characteristics of turbulent nanofluid flow in a helical tube in the tube heat exchanger (HTTHE) were assessed numerically through computational fluid dynamics (CFD) simulation. The findings of both the turbulent models: realizable k-epsion (k-ε) and re-normalisation group (RNG) k-epsilon were compared. The temperature distribution contours show that realizable and RN...
متن کاملمنابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ذخیره در منابع من قبلا به منابع من ذحیره شده{@ msg_add @}
عنوان ژورنال
دوره 38 شماره 1
صفحات 243- 253
تاریخ انتشار 2019-02-01
با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023