A Method to Design Shell-Side Pressure Drop Constrained Tubular Heat Exchangers

1977 ◽  
Vol 99 (3) ◽  
pp. 441-448 ◽  
Author(s):  
K. P. Singh ◽  
M. Holtz

In shell and tube heat exchangers, the triple segmental baffle arrangement has been infrequently used, even though the potential of this baffle system for high thermal effectiveness with low pressure drop is generally known. This neglect seems to stem from the lack of published design guidelines on the subject. Lately, however, with the rapid growth in the size of nuclear heat exchangers, the need to develop unconventional baffling pattern has become increasingly important. A method to effectively utilize the triple segmental concept to develop economical designs is presented herein. The solution technique given in this paper is based on a flow model named “Piecewise Continuous Cosine Model.” The solution procedure easily lends itself to detailed analysis to determine safety against flow-induced vibrations.

1965 ◽  
Vol 8 (32) ◽  
pp. 644-651 ◽  
Author(s):  
Seikan ISHIGAI ◽  
Eiichi NISHIKAWA ◽  
Yoshiaki NAKAYAMA ◽  
Shigeo TANAKA ◽  
Ikuo SAIDA ◽  
...  

1965 ◽  
Vol 31 (223) ◽  
pp. 419-426
Author(s):  
Seikan ISHIGAI ◽  
Eiichi NISHIKAWA ◽  
Yoshiaki NAKAYAMA ◽  
Shigeo TANAKA ◽  
Ikuo SAIDA ◽  
...  

Author(s):  
Rong Yu ◽  
Andrew D. Sommers ◽  
Nicole C. Okamoto ◽  
Koushik Upadhyayula

In this study, we have explored the effectiveness of heat exchangers constructed using anisotropic, micro-patterned aluminum fins to more completely drain the condensate that forms on the heat transfer surface during normal operation with the aim of improving the thermal-hydraulic performance of the heat exchanger. This study presents and critically evaluates the efficacy of full-scale heat exchangers constructed from these micro-grooved surfaces by measuring dry/wet air-side pressure drop and dry/wet air-side heat transfer data. The new fin surface design was shown to decrease the core pressure drop of the heat exchanger during wet operation from 9.3% to 52.7%. Furthermore, these prototype fin surfaces were shown to have a negligible effect on the heat transfer coefficient under both dry and wet conditions while at the same time reducing the wet airside pressure drop thereby decreasing fan power consumption. That is to say, this novel fin surface design has shown the ability, through improved condensate management, to enhance the thermal-hydraulic performance of plain-fin-and-tube heat exchangers used in air-conditioning applications. This paper also presents data pertaining to the durability of the alkyl silane coating.


Author(s):  
Ali Roheim El-Ghalban ◽  
Qamar Iqbal ◽  
Shahab Khushnood ◽  
M. Arshad Qureshi ◽  
M. Shahid Khalil

Flow-induced vibration in heat exchangers has been a key source of concern in the process, power generation and nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported. Design of tube bundles with loosely supported tubes in baffles for process shell and tube heat exchanger and steam generator needs estimation of energy dissipation mechanisms or damping for a safer and long term operation. Damping has a major influence on the flow induced vibrations and is dependant on a variety of factors such as mechanical properties of the tube material, geometry and number of intermediate supports, the physical properties of shell-side fluid, type of tube motion, tube frequency, shell-side temperature etc. Various damping mechanisms have been identified and quantified such as Friction damping, Viscous damping, Squeeze film damping, Support damping and Two-Phase damping which affect the performance with respect to flow induced vibration design, including standard design guidelines. But generally the effects of the higher operating temperatures on the various damping mechanisms are neglected in the general design procedure. The operating temperatures play significant role on the contribution of various damping mechanisms. The current paper focuses on the thermal aspects of damping mechanisms subjected to single phase cross-flow in process heat exchangers and formulates the design guidelines for safer design based on experimental and empirical formulations. The research results show that he increase in the temperature results in the increase of the damping. Moreover it found that the natural frequency is higher for lower mass flow rate and lower working pressures and lower temperatures.


Author(s):  
Michael Bichnevicius ◽  
David Saltzman ◽  
Stephen Lynch

Abstract Additive manufacturing (AM) enables improved heat exchanger (HX) designs where performance is based on the achievable geometry. However, consequences of the AM process that affect HX performance such as increased surface roughness, dimensional tolerance issues, and defects like cracks may vary among identically designed AM parts due to AM machine settings. This paper experimentally compares the thermal and hydraulic performance of three AM HXs built using a traditionally manufactured, stamped aluminum oil cooler design. The AM HXs exhibited significantly higher air-side pressure drop and higher heat transfer rate than the traditional HX in large part due to increased AM surface roughness. Among AM HXs, one AM HX had notably higher heat transfer rate and air-side pressure drop due to poor print quality on the thin air-side fin features. The fin thickness among AM HXs also varied by about 15%, and there were only slight differences in surface roughness. This study indicates that functional HXs built using AM vary in performance even when the same digital model is used to print them and that AM HXs as a group can perform considerably differently than their traditional counterparts.


1991 ◽  
Vol 113 (1) ◽  
pp. 30-36
Author(s):  
M. M. Zdravkovich

This is neither an original paper nor a review, but a comparative overview of two seemingly unrelated engineering fields. There are some similarities and strong dissimilarities between multipipe risers and tube arrays employed in heat exchangers. For example, square arrays are used in both, whereas “satellite” clusters cannot be found in heat exchangers. The extensive research on flow-induced vibrations in heat exchanger arrays reveals several mechanisms of excitation and sustenance of tube vibration. Some of the mechanisms identified for tube arrays may be relevant for marine risers. The main object of this comparative overview is to compile and discuss heat exchanger data which may be applicable to marine risers. Design guidelines are specified for satellite clusters.


2019 ◽  
Vol 99 ◽  
pp. 24-29 ◽  
Author(s):  
Saša Marković ◽  
Branislav Jaćimović ◽  
Srbislav Genić ◽  
Miloš Mihailović ◽  
Uroš Milovančević ◽  
...  

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