The Experts below are selected from a list of 6315 Experts worldwide ranked by ideXlab platform
Jongug Jeon - One of the best experts on this subject based on the ideXlab platform.
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cooling performance of a hybrid refrigeration system designed for Telecommunication Equipment rooms
Applied Thermal Engineering, 2007Co-Authors: Jongmin Choi, Jongug JeonAbstract:Abstract During the last several years, the power density and thermal density of Telecommunication Equipments have been increased. The optimum control of the PCB surface temperature is very important for obtaining high performance and operation reliability of Telecommunication Equipments. In this study, the cooling characteristics of Telecommunication Equipments were measured and analyzed as a function of the Equipments’ heat density. In addition, the performance of a novel hybrid refrigeration system for Telecommunication Equipment rooms was measured at various operating conditions. The PCB surface temperature ranged from 35 to 60 °C, which was relatively higher than the air temperature due to heat trapping and improper air distribution. The hybrid refrigeration system operated in the vapor compression cooling mode at high outdoor temperatures, but in the secondary fluid cooling mode at low outdoor temperatures. The outdoor temperature for the mode switch was approximately 8.3 °C. The COP of the hybrid refrigeration system was significantly enhanced at low outdoor temperatures as compared with the conventional vapor compression system due to no operation of the compressor.
Michael Pecht - One of the best experts on this subject based on the ideXlab platform.
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a multiple stage approach to mitigate the risks of Telecommunication Equipment under free air cooling conditions
Energy Conversion and Management, 2012Co-Authors: Jun Dai, Diganta Das, Michael PechtAbstract:Abstract The Telecommunication industry is concerned about the energy costs of its operating infrastructure and the associated greenhouse gas emissions. At present, more than half of the total energy consumption of data centers is devoted to the power and cooling infrastructure that supports electronic Equipment. One method of reducing energy consumption is an approach called “free air cooling,” where ambient air is used to cool the Equipment directly, thereby reducing the energy consumed in cooling and conditioning the air. For example, Intel demonstrated free air cooling in a 10-megawatt (MW) data center, showing a reduction in energy use and savings of US$2.87 million annually. However, the impacts of this approach on the performance and reliability of Telecommunication Equipment need to be identified. The implementation of free air cooling changes the operating environment, including temperature and humidity, which may have a significant impact on the performance and reliability of telecom Equipment. This paper discusses the challenges posed by free air cooling and presents a multi-stage process for evaluating and mitigating the potential risks arising from this new operating environment.
Yang Liu - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of a supersized aluminum flat plate heat pipe for natural cooling of high power Telecommunication Equipment
Applied Thermal Engineering, 2021Co-Authors: Guohui Zhou, Yang LiuAbstract:Abstract The large-sized heat spreader plays an important role in strengthening the heat dissipation of outdoor Telecommunication Equipment. If simply enlarging the traditional vapor chamber structure, it faces the shortcomings of complex structure, difficulty in manufacturing, and low mechanical strength. In this paper, guided by a theoretical analysis, a super-large aluminum-based flat heat pipe (FHP) heat spreader with the overall size of 420mm × 210 mm × 6.3 mm was developed and systematically studied under natural convection condition. The results show that the proposed aluminum FHP can effectively manage thermal loads up to 80 W in the vertical gravity-favorable direction with the heat source temperature below 78.9 °C, which is much lower than that of an aluminum plate with the same geometric size. At the same time, the proposed flat heat pipe was combined with a finned heat sink to test the heat dissipation capability of the module under natural convection condition. The FHP heat sink module can effectively dissipate 150 W of heating power with a local heat flux of 24 W/cm2 when placed vertically before the substrate temperature of the module approaches to 80 °C, and reduce the temperature of the heat source by 20 °C compared to a traditional aluminum finned heat sink module with the same geometries. The proposed aluminum FHP provides a promising thermal management solution for high-power Telecommunication Equipment, and exhibits high potential for cooling high power laser, power batteries, and LED lamps, etc.
Jongmin Choi - One of the best experts on this subject based on the ideXlab platform.
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cooling performance of a hybrid refrigeration system designed for Telecommunication Equipment rooms
Applied Thermal Engineering, 2007Co-Authors: Jongmin Choi, Jongug JeonAbstract:Abstract During the last several years, the power density and thermal density of Telecommunication Equipments have been increased. The optimum control of the PCB surface temperature is very important for obtaining high performance and operation reliability of Telecommunication Equipments. In this study, the cooling characteristics of Telecommunication Equipments were measured and analyzed as a function of the Equipments’ heat density. In addition, the performance of a novel hybrid refrigeration system for Telecommunication Equipment rooms was measured at various operating conditions. The PCB surface temperature ranged from 35 to 60 °C, which was relatively higher than the air temperature due to heat trapping and improper air distribution. The hybrid refrigeration system operated in the vapor compression cooling mode at high outdoor temperatures, but in the secondary fluid cooling mode at low outdoor temperatures. The outdoor temperature for the mode switch was approximately 8.3 °C. The COP of the hybrid refrigeration system was significantly enhanced at low outdoor temperatures as compared with the conventional vapor compression system due to no operation of the compressor.
Pierre Hadaya - One of the best experts on this subject based on the ideXlab platform.
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electronic commerce and supply chain integration the case of the Telecommunication Equipment industry
Business Process Management Journal, 2005Co-Authors: Luc Cassivi, Pierremajorique Leger, Pierre HadayaAbstract:Purpose – This paper presents an analysis of the impact of electronic commerce on firms in the Telecommunications Equipment industry.Design/methodology/approach – Using the OECD's value chain methodology, electronic commerce initiatives identified in the optical connectivity value chain were analyzed for each of the four layers of the chain, namely network operators, system integrators, assemblers and sub‐assemblers.Findings – The findings from our case studies indicate that electronic commerce initiatives primarily influence process and relational innovations through supply chain collaboration. The real benefits of electronic commerce come from end‐to‐end visibility in the supply chain, and from the implementation of demand‐pull strategies for all levels of the optical connectivity Equipment value chain.Research limitations/implications – Future research should concentrate on the impact of various emerging electronic marketplaces in demand‐driven integrated supply chains.Originality/value – Results revea...
