Force Air Cooled Electronic Equipment Under Loss of Cooling Condition With Blocked Air Duct

2007 ◽  
Author(s):  
Frank Fan Wang
Keyword(s):  
Thermal Design ◽  
Electronic Equipment ◽  
Cooling Condition ◽  
Worst Case ◽  
Aerospace Applications ◽  
Air Inlet ◽  
Design Options ◽  
Forced Cooling ◽  
Cooling Air ◽  
Mean Time

There are many electronic equipments are cooled by forced cooling airs. Some equipment’s forced cooling air is supplied by air ducts, where air blower is located at a distance. In many cases, when the remote blower is out of order, the buoyancy of heated air cannot generate enough pressure to overcome the long air ducts and the blower. There is no air flow at all through the normal cooling air duct. That is called loss of cooling thermal condition. Loss of cooling condition is usually the worst case thermal challenge. In aerospace applications, most forced convection cooled electronic equipments need to meet the loss of cooling operation requirement. During loss of cooling, the electronic equipment needs to obtain cooler ambient surrounding air from a different inlet other than the supply air inlet. However, the passive cooling air inlet cannot interfere with the normal cooling situation. In normal cooling situation, forced cooling air is provided to lower the electronics temperature to a level of meeting the mean time between failure (MTBF) requirements. This paper will discuss a few trade studies of how different design approaches meet this loss of cooling air challenges; present a detailed CFD calculation of one of the design options. Many other considerations are also to be presented other than just thermal design concerns.

Flow Resistance Network Analysis in Fan-Cooled High-Density Packaging Electronic Equipment

2015 ◽  
Author(s):  
Takashi Fukue ◽  
Tomoyuki Hatakeyama ◽  
Masaru Ishizuka ◽  
Koichi Hirose ◽  
Kazuma Obata ◽  
...  
Keyword(s):  
Network Analysis ◽  
Flow Resistance ◽  
High Density ◽  
Thermal Design ◽  
Electronic Equipment ◽  
Test Model ◽  
Resistance Network ◽  
Electrical Components ◽  
Cooling Air ◽  
High Density Packaging

This study describes an application of the flow resistance network analysis to thermal design of fan-cooled electronic equipment. Especially, a modeling method of the flow resistance network was investigated. Current electronic equipment becomes smaller and thinner while their functions become more complex. As a result, flow passages for cooling air become complex. In order to simulate the complex airflow in high-density packaging electronic equipment by using the flow resistance network, we tried to develop the flow resistance network by support of the 3D-CFD analysis. A test model which simulates high-density packaging electronic equipment is prepared and the flow resistance network analysis is applied to the prediction of flow rate distribution in the model. Through the investigation, we obtained information and future problems about the development of the flow resistance network in electronic equipment with lots of electrical components.

Investigation and Application of Forced Cooling of WH 600MW Steam Turbine

2013 ◽  
Vol 732-733 ◽  
pp. 242-249
Author(s):  
Yong Feng Shi ◽  
Jian Qun Xu ◽  
Lin Ma
Keyword(s):  
Numerical Analysis ◽  
Steam Turbine ◽  
Cooling Rate ◽  
Control Strategy ◽  
Cooling Condition ◽  
Practical Application ◽  
Cooling Process ◽  
Quantitative Calculation ◽  
Forced Cooling ◽  
Cooling Air

With a long natural cooling time after a shutdown of steam turbine restricting its available coefficient, this paper presented the analysis and application of a forced cooling process to sub-critical steam turbine. The radiating mechanism of natural cooling was analyzed theoretically, and the required amount of cooling air was calculated for a WH 600MW steam turbine. Moreover, the cooling rate with no life loss principle was determined by the method of quantitative calculation and numerical analysis, together with safety analysis. The research discussed the control strategy of practical application according with steam turbine characteristic and applied to operation, which provided theoretical guidance for the optimization of cooling condition.

Optimum Range Thermal Design With Computational Fluid Dynamics

2003 ◽  
Author(s):  
Prabhat Tekriwal
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Consumer Preference ◽  
Design Tool ◽  
Thermal Design ◽  
Good Design ◽  
Optimum Range ◽  
Consumer Safety ◽  
Temperature Requirements ◽  
Design Options

A typical cooking range design requires that UL temperature requirements be met on outside surfaces for consumer safety. Another important consumer preference is that the range oven cavity be large in capacity so that it provides more cooking flexibility to consumers. These two requirements are in conflict with each other from design standpoint. CFD (Computational Fluid Dynamics) has proven to be a good design tool in balancing these opposing requirements and providing a optimum design without having to experiment with several design options and prototyping. The width of the air-wash that is used to cool the cooking range door through natural convection has been optimized with the aid of computational fluid dynamics. Increasing the air-wash width helps reduce the door surface temperature up to certain point, beyond which no gains in temperature reduction are realized.

Categorized Application Technology of Numerical Simulation on Electronic Equipment Thermal Design

2009 ◽  
Author(s):  
Yasuyuki Yokono ◽  
Katsumi Hisano ◽  
Kenji Hirohata
Keyword(s):  
Numerical Simulation ◽  
Product Development ◽  
Statistical Approach ◽  
Thermal Design ◽  
Electronic Equipment ◽  
Product Development Process ◽  
Design Stage ◽  
Application Technology ◽  
Simulation Techniques ◽  
Simulation Based

In order to utilize a numerical simulation on a product development for electronic equipment, not only the simulation techniques themselves, but the application technologies of the simulation in the product design, were examined. The design process of electronic equipment was categorized into four stages, which were a concept, a function, a layout and a parameter design. Each design stage consists of a specifying that a human decide the specification for the next stage and a verification whether the specification satisfy the previous stage requirements. The specifying and the verification are conducted over and over again. Numerical simulation is corresponded to the verification and is used to accelerate this iteration instead of experiments. The examples of numerical simulation corresponding to these four verifications were shown in the present paper. There are few examples in last two type of simulation. The progress of the numerical technology for function and concept verification is expected. The product development process requires not only numerical simulation based on physics but also statistical approach.

scholarly journals Systemic Approach Applied to Dual Pressure HRSG

1997 ◽  
Author(s):  
B. Leide ◽  
R. Gicquel
Keyword(s):  
Heat Recovery ◽  
Heat Supply ◽  
Process Integration ◽  
Thermal Design ◽  
Thermal System ◽  
Basic Process ◽  
Heat Recovery Steam Generator ◽  
Heat Exchange Surface ◽  
Design Options ◽  
Exchange Surface

Starting from a traditionally designed heat exchanger arrangement, a dual pressure and supplementary fired heat recovery steam generator (HRSG) has been examined according to a novel thermal design approach which features thermodynamic loss analyses being separately applied to individual components and to the thermal system as a whole. Basic Process Integration tools are employed in order to unveil the utility target. In addition recently developed analysis tools which are especially adapted to heat recovery equipment are introduced and then applied to the HRSG. Design modifications are identified which lead to an encouraging −8% reduction of heat exchange surface with respect to initial design while steam load and utility heat supply (by means of post-combustion) are kept unchanged. The design options are commented step by step and reflected against engineering feasibility as well as their overall economic impact.

Thermal Design, Analysis and Experimental Verification of Electronic Equipment of a Satellite Borne Microwave Radiometer

2013 ◽  
Vol 655-657 ◽  
pp. 84-87 ◽  
Author(s):  
Bo Chen
Keyword(s):  
Thermal Analysis ◽  
Finite Element ◽  
Microwave Radiometer ◽  
Engineering Application ◽  
Element Model ◽  
Thermal Design ◽  
Electronic Equipment ◽  
Element Analysis ◽  
Experiment Verification ◽  
Experimental Values

Thermal design, finite element analysis and experiment verification of electronic equipment of a satellite borne microwave radiometer are introduced. Some methods were adopted to help heat conduct and a finite element model was built. The analysis results show that the temperature scopes of the main structures are from 45°C to63.9°C in the digital control equipment and 45°C to 68.7°C in the receiver equipment and all of junction temperatures of the components are lower than the derated maximum junction temperatures themselves and leave enough design margins, which match the requirements of thermal analysis. The experimental results show that the computing values are close to experimental values and the largest error is 10.1°C, which is allowed for engineering application.

Thermal design of the vertical machining centre headstock by the forced cooling method

2011 ◽  
Vol 226 (3) ◽  
pp. 738-751 ◽  
Author(s):  
S Jiang ◽  
X Min
Keyword(s):  
Cooling System ◽  
Structural Parameters ◽  
Thermal Design ◽  
Air Cooling ◽  
Thermal Drift ◽  
Cooling Method ◽  
Spindle Axis ◽  
Forced Air ◽  
Dip Angle ◽  
Forced Cooling

The headstock thermal drift is a major source of the machining error for a vertical machining centre. However, the research so far reported has been unable to provide a satisfactory method to eliminate the spindle axis dip angle resulting from the thermal drift. In this article, a thermal design is carried out for the vertical machining centre headstock by introducing a dual cooling system, utilizing forced water cooling subsystem and a forced air cooling one. An integrated thermal model of the vertical machining centre headstock has been established by aid of the finite element method, and the appropriate structural parameters of the dual cooling system have been analysed. The theoretical results were verified by an experiment in which the perpendicularity between worktable surface and the spindle axis resulting from the thermal displacement is measured. The results indicate that the thermal behaviour of the vertical machining centre headstock can be improved using the dual cooling method.

Model for predicting performance of cooling fans for thermal design of electronic equipment (Modeling and evaluation of effects from electronic enclosure and inlet sizes)

2011 ◽  
Vol 40 (4) ◽  
pp. 369-386 ◽  
Author(s):  
Takashi Fukue ◽  
Masaru Ishizuka ◽  
Shinji Nakagawa ◽  
Tomoyuki Hatakeyama ◽  
Katsuhiro Koizumi
Keyword(s):  
Thermal Design ◽  
Electronic Equipment ◽  
Predicting Performance ◽  
Cooling Fans
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