Heat Conduction Through a Layered Pressure Vessel Wall

1986 ◽  
Vol 108 (4) ◽  
pp. 418-422
Author(s):  
M. Ueda ◽  
M. Kinugawa ◽  
Y. Hara ◽  
K. Yamazato
Keyword(s):  
Heat Conduction ◽  
Pressure Vessel ◽  
Vessel Wall ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Postweld Heat Treatment ◽  
Pressure Vessels ◽  
Scale Model ◽  
Thermal Contact Conductance ◽  
Simplified Method

Heat conduction tests of a layered pressure vessel wall were performed using full-scale model pressure vessel courses. Thermal conductance between layers was estimated from the test results. A simplified method, developed for the thermal analysis of layered-wall pressure vessels during postweld heat treatment and actual operation, includes thermal contact conductance at the layer interfaces which depends upon the contact pressure and gap height. Temperature changes calculated using the simplified method agreed well with the experiments.

scholarly journals Demonstration of a Compliant Micro-Spring Array As a Thermal Interface Material for Pluggable Optoelectronic Transceiver Modules

2019 ◽  
Author(s):  
Jin Cui ◽  
Liang Pan ◽  
Justin A. Weibel
Keyword(s):  
Heat Sink ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Thermal Interface Material ◽  
Thermal Contact Conductance ◽  
Compression Pressure ◽  
Thermal Interface ◽  
Operation Temperature ◽  
Optical Module ◽  
Dry Contact

Abstract Pluggable optoelectronic transceiver modules are widely used in the fiber-optic communication infrastructure. It is essential to mitigate thermal contact resistance between the high-power optical module and its riding heat sink in order to maintain the required operation temperature. The pluggable nature of the modules requires dry contact thermal interfaces that permit repeated insertion–disconnect cycles under low compression pressures (∼10–100 kPa). Conventional wet thermal interface materials (TIM), such as greases, or those that require high compression pressures, are not suitable for pluggable operation. Here we demonstrate the use of compliant micro-structured TIM to enhance the thermal contact conductance between an optical module and its riding heat sink under a low compression pressure (20 kPa). The metallized and polymer-coated structures are able to accommodate the surface nonflatness and microscale roughness of the mating surface while maintaining a high effective thermal conductance across the thickness. This dry contact TIM is demonstrated to maintain reliable thermal performance after 100 plug-in and plug-out cycles while under compression.

A Proposed Method for Anticipated-Allowable Piping, Mechanical and Seismic Nozzle Load Design

2004 ◽  
Author(s):  
Ch. Botsis ◽  
G. Anagnostides ◽  
N. Kokavesis
Keyword(s):  
Pressure Vessel ◽  
Vessel Wall ◽  
Theoretical Work ◽  
Practical Experience ◽  
Pressure Vessels ◽  
External Radius ◽  
Important Constraint ◽  
Design Loads ◽  
The Difference ◽  
Heuristic Estimate

Nozzle loads impose an important constraint in the design of pressure containing equipment. Pressure vessels are connected to external piping by a nozzle welded to the vessel wall and a flange connection. The nozzle loads are due to the piping expansion or contraction caused by the difference between the installation and operating temperatures. Pressure vessel designers need to know, early in the design process, the piping loads that a nozzle may be subjected to. It is important that such loads do not overstress the vessel-nozzle intersection. However the actual piping loads many times are only determined long after the pressure vessel materials are ordered and even procured. The intention of this paper is to provide an empirical but also realistic load set as a function of nozzle external radius, r, vessel external radius, R, vessel thickness, t, and allowable stress, S. The basis of this work is practical experience and also existing theoretical work. This will be a valuable tool in the hands of the pressure vessel mechanical designer. It will allow him to prescribe an early-heuristic estimate of the allowable nozzle loads that will cover external piping loads. These “anticipated” or design loads will allow a pressure vessel mechanical designer to reinforce his design early into the manufacturing of a pressure vessel. Finally, piping engineers will know the terminal allowable loads and thus determine the best piping routing and support arrangements if space constraints allow it.

Recent Developments in Contact Conductance Heat Transfer

1988 ◽  
Vol 110 (4b) ◽  
pp. 1059-1070 ◽  
Author(s):  
L. S. Fletcher
Keyword(s):  
Heat Transfer ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Thermal Contact Conductance ◽  
Contact Conductance ◽  
Thermal Rectification ◽  
Numerical Studies ◽  
Wide Range ◽  
Theoretical Investigations ◽  
Recent Developments

The characteristics of thermal contact conductance are increasingly important in a wide range of technologies. As a consequence, the number of experimental and theoretical investigations of contact conductance has increased. This paper reviews and categorizes recent developments in contact conductance heat transfer. Among the topics included are the theoretical/analytical/numerical studies of contact conductance for conforming surfaces and other surface geometries; the thermal conductance in such technological areas as advanced or modern materials, microelectronics, and biomedicine; and selected topics including thermal rectification, gas conductance, cylindrical contacts, periodic and sliding contacts, and conductance measurements. The paper concludes with recommendations for emerging and continuing areas of investigation.

A three-dimensional fractal theory based on thermal contact conductance model of rough surfaces

2017 ◽  
Vol 232 (5) ◽  
pp. 528-539 ◽  
Author(s):  
Yongsheng Zhao ◽  
Cui Fang ◽  
Ligang Cai ◽  
Zhifeng Liu
Keyword(s):  
Rough Surfaces ◽  
Fractal Theory ◽  
Thermal Contact ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Engineering Application ◽  
Thermal Contact Conductance ◽  
Real Contact Area ◽  
Contact Conductance ◽  
Elastic Plastic

The thermal contact conductance is an important problem in the field of heat transfer. In this research, a three-dimensional fractal theory based on the thermal contact conductance model is presented. The topography of the contact surfaces was fractal featured and determined by fractal parameters. The asperities in the microscale were considered as elastic, elastic-plastic, or plastic deformations. The real contact area of the asperities could be obtained based on the Hertz contact theory. It was assumed that the rough contact surface was composed of numerous discrete and parallel microcontact cylinders. Consequently, the thermal contact conductance of the surface roughness was composed of the thermal constriction conductance of microcontacts and the air medium thermal conductance of microgaps. The thermal contact conductance of rough surfaces could be calculated by the microasperities integration. An experimental set-up with annular interface was designed to verify the presented thermal contact conductance model. Three materials were used for the thermal contact conductance analysis with different fractal dimensions D and fractal roughness parameters G. The numerical results demonstrated that the thermal contact conductance could be affected by the elastic-plastic deformation of the asperities and the gap thermal conductance should not be ignored under the lower contact load. The presented model would provide a theoretical basis for thermal transfer engineering application.

Thermal Contact Conductance of Spherical Rough Metals

1997 ◽  
Vol 119 (4) ◽  
pp. 684-690 ◽  
Author(s):  
M. A. Lambert ◽  
L. S. Fletcher
Keyword(s):  
Nuclear Reactor ◽  
Combustion Engine ◽  
Fundamental Problem ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Thermal Control ◽  
Cryogenic Liquid ◽  
Thermal Contact Conductance ◽  
Thermomechanical Model ◽  
Contact Conductance

Junction thermal conductance is an important consideration in such applications as thermally induced stresses in supersonic and hypersonic flight vehicles, nuclear reactor cooling, electronics packaging, spacecraft thermal control, gas turbine and internal combustion engine cooling, and cryogenic liquid storage. A fundamental problem in analyzing and predicting junction thermal conductance is determining thermal contact conductance of nonflat rough metals. Workable models have been previously derived for the limiting idealized cases of flat, rough, and spherical smooth surfaces. However, until now no tractable models have been advanced for nonflat rough “engineering” surfaces which are much more commonly dealt with in practice. The present investigation details the synthesis of previously derived models for macroscopically nonuniform thermal contact conductance and contact of nonflat rough spheres into a thermomechanical model, which is presented in an analytical/graphical format. The present model agrees well with representative experimental conductance results from the literature for stainless steel 303 and 304 with widely varying nonflatness (2 to 200 μm) and roughness (0.1 to 10 μm).

Manufacture of Advanced 2.25Cr-1Mo-V Pressure Vessel Steel for High Pressure and High Temperature Hydrogen Service

2004 ◽  
Author(s):  
T. Hasegawa ◽  
A. Narita ◽  
H. Iga ◽  
S. Inoue
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Pressure Vessel ◽  
Base Material ◽  
Postweld Heat Treatment ◽  
Pressure Vessels ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Manufacturing Technologies ◽  
Welding Consumables

At this moment, the materials which are applied for high pressure and high temperature services are selected from conventional 2.25Cr-1Mo, 3Cr-1Mo-V and 2.25Cr-1Mo-V steels. Especially, the application of 2.25Cr-1Mo-V steel is increased extremely rather than the other steels in order to take the advantage of higher strength and better resistance to hydrogen damages such as hydrogen attack, hydrogen assisted crack growth and also hydrogen induced disbonding. In order to achieve these properties, the vanadium element is added intentionally into base material and welding consumables. Due to the addition of vanadium, the engineer have recognized that there is some possibility of cracking in the weldment due to the higher hardness and insufficient manufacturing practices caused by lack of knowledge for preheating, intermediate/final postweld heat treatment and other factors. The manufacturers have to establish the proper technologies to avoid this problem during fabrication stage while the pressure vessels are to be fabricated in their shop and/or fields. In this paper, the manufacturing technologies of 2.25Cr-1Mo-V steel pressure vessel through actual fabrication is presented herewith.

scholarly journals Demonstration of a Compliant Microspring Array as a Thermal Interface Material for Pluggable Optoelectronic Transceiver Modules

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Jin Cui ◽  
Liang Pan ◽  
Justin A. Weibel
Keyword(s):  
Heat Sink ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Thermal Interface Material ◽  
Thermal Contact Conductance ◽  
Compression Pressure ◽  
Thermal Interface ◽  
Operation Temperature ◽  
Optical Module ◽  
Dry Contact

Abstract Pluggable optoelectronic transceiver modules are widely used in the fiber-optic communication infrastructure. It is essential to mitigate thermal contact resistance between the high-power optical module and its riding heat sink in order to maintain the required operation temperature. The pluggable nature of the modules requires dry contact thermal interfaces that permit repeated insertion–disconnect cycles under low compression pressures (∼10 to 100 kPa). Conventional wet thermal interface materials (TIM), such as greases, or those that require high compression pressures, are not suitable for pluggable operation. Here, we demonstrate the use of compliant microstructured TIM to enhance the thermal contact conductance between an optical module and its riding heat sink under a low compression pressure (20 kPa). The metallized and polymer-coated structures are able to accommodate the surface nonflatness and microscale roughness of the mating surface while maintaining a high effective thermal conductance across the thickness. This dry contact TIM is demonstrated to maintain reliable thermal performance after 100 plug-in and plug-out cycles while under compression.

scholarly journals Identification of the Thermal Conductance of a Hidden Barrier from Outer Thermal Data

2021 ◽  
Vol 8 (1) ◽  
pp. 16
Author(s):  
Gabriele Inglese ◽  
Roberto Olmi ◽  
Agnese Scalbi
Keyword(s):  
Heat Transfer ◽  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Thin Plate ◽  
Thermal Contact ◽  
Thermal Conductance ◽  
Thermal Contact Conductance ◽  
Composite Slab ◽  
Thermal Data ◽  
Investigate Heat Transfer

Hidden defects affecting the interface in a composite slab are evaluated from thermal data collected on the upper side of the specimen. First we restrict the problem to the upper component of the object. Then we investigate heat transfer through, the inaccessible interface by means of Thin Plate Approximation. Finally, a Fast Fourier Transform is used to filter data. In this way, we obtain a reliable reconstruction of simulated flaws in thermal contact conductance corresponding to appreciable defects of the interface.

scholarly journals Nanoscale Heat Conduction in CNT-POLYMER Nanocomposites at Fast Thermal Perturbations

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2794 ◽  
Author(s):  
Minakov ◽  
Schick
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Heat Conduction ◽  
Polymer Matrix ◽  
Transfer Problem ◽  
Thermal Contact ◽  
Heat Transfer Process ◽  
Thermal Contact Conductance ◽  
Local Overheating ◽  
Thermal Perturbations

Nanometer scale heat conduction in a polymer/carbon nanotube (CNT) composite under fast thermal perturbations is described by linear integrodifferential equations with dynamic heat capacity. The heat transfer problem for local fast thermal perturbations around CNT is considered. An analytical solution for the nonequilibrium thermal response of the polymer matrix around CNT under local pulse heating is obtained. The dynamics of the temperature distribution around CNT depends significantly on the CNT parameters and the thermal contact conductance of the polymer/CNT interface. The effect of dynamic heat capacity on the local overheating of the polymer matrix around CNT is considered. This local overheating can be enhanced by very fast (about 1 ns) components of the dynamic heat capacity of the polymer matrix. The results can be used to analyze the heat transfer process at the early stages of “shish-kebab” crystal structure formation in CNT/polymer composites.

Measurements and Models for the Thermal Conductance Through Surfaces Joined by Screws

2013 ◽  
Author(s):  
Nicholas Konkle ◽  
Adam Pautsch ◽  
Yosef Amir
Keyword(s):  
Thermal Contact ◽  
Applied Pressure ◽  
Thermal Conductance ◽  
Electronics Cooling ◽  
Experimental Results ◽  
Thermal Contact Conductance ◽  
Poor Correlation ◽  
Published Data ◽  
Conduction Path ◽  
Interstitial Material

In electronics cooling with limited local convective or irradiative cooling, conduction path optimization is critical. Decreased junction temperatures (resulting in increased performance and reliability) can be achieved by maximizing the conductance through screw joints. Thermal contact conductance across an Aluminum-Aluminum screw joint was experimentally measured which compared well with published data for uniformly distributed pressure, with increasing conductance versus the published data as the screw preload was applied. The geometry was modeled using a meshed surface application of an available model for thermal conductance of contacts with uniformly-applied pressure, resulting in a poor correlation due to limitations in the applied technique. Modifications to the model were explored, including capping pressure, imposing a non-zero pressure in the area not influenced by screw pressure, simplifying the pressure distribution, and scaling the model to match experimental results. Each resulted in somewhat better correlation between calculated and experimental results. Recommendations are made regarding the calculation of conductance in general, leaning toward more simplified models. Further work is suggested in the area of experimentally-verified modeling of other materials and surface conditions, geometry, and with an interstitial material other than air.

Sign in / Sign up

Export Citation Format

Share Document