RESEARCH FOR THERMAL MITIGATION OF THE SERVER ROOM WITH OLD BUILDING SPECIFICATION

Author(s):  
Emi Tomita ◽  
◽  
Shoichi Kojima ◽  
Keyword(s):  
1992 ◽  
Vol 4 (1) ◽  
pp. 67-77 ◽  
Author(s):  
JoAnn C. Radway ◽  
Joseph C. Weissman ◽  
Edward W. Wilde ◽  
John R. Benemann

2017 ◽  
Vol 24 ◽  
pp. 92-100 ◽  
Author(s):  
Yoshikazu Tanaka ◽  
Shigeto Kawashima ◽  
Takehide Hama ◽  
Kimihito Nakamura

Author(s):  
Kenton Pike ◽  
Gang Duan ◽  
Jason Sun ◽  
Paul Jukes

Thermal expansion and global buckling is a critical design aspect for subsea flowline systems subjected to high pressure and high temperature (HPHT). In the Gulf of Mexico, HPHT oil/gas production is becoming exceedingly common as drilling and production depths extend deeper. Advanced finite element analysis becomes essential for flowline expansion and buckling design which is highly dependent on pipe-soil interaction behavior. For decades, pipe-soil interaction has been the focus of many research studies and joint industry projects. For HPHT flowline systems, thermal mitigation is decisive for safe design. Thermal mitigation acts to control global buckling at designate locations and avoid buckling in unknown locations. Thermal mitigation results in significant cost savings by lowering the welding class besides the buckling locations and increases safety in terms of local buckling, fracture, and fatigue. One widely used thermal mitigation method involves attaching a buoyancy module around a segment of the flowline. In this paper the Coupled Eulerian Langrangian (CEL) finite element (FE) formulation is utilized to simulate the interaction between soil and the thermal mitigation buoyancy module (TMBM). The paper demonstrates the capability of the CEL FE method to simulate large soil deformation without the numerical difficulties that are commonly associated with other numerical formulations e.g. ALE (Arbitrary Lagrangian Eulerian) or more conventional Lagrangian. Initially, a three dimensional (3D), continuum, FE model is used to establish the variation of initial embedment along the length of the buoyancy and adjoining pipe. The study then establishes the lateral displacement/resistance relationships under different levels of contact pressure and soil embedment for a series of buoyancy-soil interaction segments, also using the CEL FE method. Current practice for global pipeline thermal expansion FEA is to utilize the same friction model for both buoyancy-soil interaction and pipe-soil interaction. The obtained buoyancy-soil interaction model from the current study is to be used as input to the global FE model to more precisely simulate flowline lateral buckling behavior. This paper presents a practical application of the current state of the art in modeling large soil deformations in providing an improved approach for modeling buoyancy-soil interactions in the global FEA of pipeline thermal expansion and lateral buckling.


2021 ◽  
Author(s):  
Kenneth N Aycock ◽  
Sabrina N. Campelo ◽  
Rafael V. Davalos

Abstract Irreversible electroporation (IRE), otherwise known as non-thermal pulsed field ablation (PFA), is an attractive focal ablation modality due to its ability to destroy aberrant cells with limited disruption of extracellular tissue architecture. Despite its non-thermal cell death mechanism, application of electrical energy results in Joule heating that, if ignored, can cause undesired thermal injury. Engineered thermal mitigation (TM) technologies including phase change materials (PCMs) and active cooling (AC) have been reported and tested in isolated preliminary studies to limit the risk of thermal damage, but their performance compared to one another is relatively unknown. Further, the effects of pulsing paradigm, electrode geometry, PCM composition, and chosen active cooling parameters have not been examined. Here, we develop a computational model of conventional bipolar and monopolar probes with solid, PCM-filled, or actively cooled cores and simulate clinical IRE treatments in pancreatic tissue. We find that probes with integrated PCM cores can be tuned to drastically limit thermal damage compared to traditional solid probes. Actively cooled probes, on the other hand, provide even more control over thermal effects within the probe vicinity and can altogether eliminate thermal damage. In practice, these differences in performance are tempered by the increased time, expense, and effort necessary to use actively cooled probes compared to traditional solid probes or those containing a PCM core.


2020 ◽  
Author(s):  
Dan Moore ◽  
Dave West

<p>This study focused on Alouette River, located in south coastal British Columbia. During summer, water is released from shallow reservoir at a near-constant rate from an outlet about 6-10 m below the water  surface. Outlet temperatures in summer 2013 were initially cool hypolimnetic water, followed by alternating cool and warm water associated with an internal seiche, and finally dominated by warm epilimnetic water during the period of highest water temperature. An energy-balance model was used to evaluate potential strategies to ameliorate thermal habitat conditions for Pacific salmon downstream of the dam. Restoration of deforested banks that represented 4% of the reach length reduced daily maximum temperatures by only about 0.5 °C , while releasing more flow exacerbated temperatures during the warmest week of the year. The only effective strategy for thermal amelioration would be to release water from deeper in the reservoir.</p>


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