• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.6
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• pp.279-288
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• 2017

Heat generation rate in a telecommunication cabinet increases due to the continued usage of mobile devices. Insufficient removal of heat intensifies the cabinet temperature, resulting in the malfunction of electronic devices. In this study, we assessed both aluminum and plastic heat exchangers used for cooling of the telecommunication cabinet, and compared the results against theoretical predictions. The aluminum heat exchanger was composed of counter flow parallel channels of 4.5 mm pitch, and the plastic heat exchangers were composed of cross flow triangular channels of 2.0 mm pitch. Samples were made by installing two plastic heat exchangers in both series and parallel. Results showed that the heat transfer rate was highest for the series cross flow heat exchanger, and was least for the aluminum heat exchanger. The temperature efficiency of the series cross flow heat exchanger was 59% greater than that of the aluminum heat exchanger, and was 4.3% greater than that of the parallel cross flow heat exchanger. In contrast, the pressure drop of the parallel cross flow heat exchanger was significantly lower than other samples. The heat exchange efficiency was also the largest for the parallel cross flow heat exchanger. The theoretical analysis predicted the temperature efficiency to be within 3.3%, and the pressure drop within 6.1%.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1385-1390
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• 2009

In this study the purpose is development of passive cooling system for telecommunication cabinet used by latent heat material. This cooling system is not required for electronic power. It was tested for the performance of the telecommunication combined latent heat material with $48^{\circ}C$ of phase changed temperature and heat pipe. At $45^{\circ}C$ of outside temperature, when heater power was 1,000 W and 1,500 W, the inside temperature of the cabinet was $55^{\circ}C$ and $62^{\circ}C$. This system was showed better performance than the other systems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.2
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• pp.87-93
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• 2009

Slim telecommunication cabinet cooler, equipped with parallel flow heat exchangers and operating with R-22, is developed. The performance is compared with imported one, equipped with fin-tube heat exchangers and operating with R-134a. Test results show that the newly-developed cooler increases the cooling capacity by 6% and EER by 33%. The refrigerant charge for the developed cooler is 500g compared with 1250g for the imported one. The adoption of parallel flow heat exchanger appears to have reduced the refrigerant charge. In addition, it is shown that the reduced air flow rates through parallel heat exchangers as compared with those through fin-tube heat exchangers are beneficial to the reduction of the equipment noise.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.7
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• pp.2356-2366
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• 1996

High-power electronic chips have been advanced to such an extent that the heat dissipation capability of a system design has become one of the primary limiting factors. Therefore, thermal design must be considered in the early stage of the electronic system development. In present paper, the results of an experimental study on the forced convection cooling are presented to evaluate cooling performance of an electronic cabinet which in generally used for telecommunication system. Temperatures and thermal resistances are applied to compare the heat transfer characteristics for various locations of a fan unit as well as various configuration of non-uniform powering modules. As a result, the optimal configuration of a fan unit and powering configuration is suggested for the effective thermal design of telecommunication system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.702-708
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• 2017

The heat generation rate in a telecommunications cabinet keeps increasing due to the increased usage of mobile devices. Insufficient removal of the heat increases the cabinet temperature, which results in the malfunction of the electronic devices. In this study, tests were conducted on aluminum and plastic heat exchangers for cooling a telecommunications cabinet, and the results were compared with theoretical predictions. The aluminum heat exchanger comprised counter flow parallel channels with 4.5-mm pitch, and the plastic heat exchangers comprised cross or cross-counter flow triangular channels with 2.0-mm pitch. The volume of the cross flow heat exchanger was the same as that of the aluminum heat exchanger, and the volume of the cross-counter heat exchanger was 33% larger than that of the aluminum heat exchanger. The results show that the heat transfer rate is the highest for the cross-counter heat exchanger and lowest for the aluminum one. The temperature efficiency of the cross-counter heat exchanger was 56% higher than that of the aluminum one and 20% higher than that of the cross flow heat exchanger. The pressure drop of the cross-counter heat exchanger was approximately the same as that of the aluminum one. The heat exchange efficiency was the highest for the cross-counter heat exchanger and lowest for the cross flow heat exchanger. The theoretical analysis somewhat overestimated or underestimated the data.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.2
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• pp.230-239
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• 1996

A multi-faceted experimental investigation has been carried out to study the cooling performance for stacked modules in arrays of heat generating rectangular modules deployed along PCB's in the enclosed cabinet. The main parameters which have an important effect on cooling characteristics are flow velocity, channel spacing, installation of fan unit, attachment of heat sink, and acoustic noise. The results of individual effect are very helpful for the electronic packaging designer. In order to improve the cooling performance, it is certain that the enlargement of channel space is obviously effective, while this id disadvantageous in high density electronic packaging. Each of the paameters is quantitatively examined as cooling performance and the correlation of Reynolds number to Nusselt number is compared with previous study.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.323-328
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• 2005

The objective of this study is to analyze the cooling performance of an air- cooling system for telecommunication equipment. Temperature variation and capacity were measured in an actual unit for telecommunication equipment. In addition, the cooling performance was measured by installing a silicon rubber heater as a heat source in a cabinet. The standard thermal load for telecommunication equipment was approximately 293 W, and the maximum temperature of the heated surface was $64.5^{\circ}C$. The average and maximum temperatures of the heated surface were proportional to the inlet air temperature. When the heat load increased from 293 W to 400 W, the maximum temperature of the heated surface was higher than $64.5^{\circ}C$ even though the inlet air temperature decreased from 25 to $11^{\circ}C$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.1
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• pp.24-30
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• 2006

Three liquid cooling heat exchangers for cooling of telecommunication equipment were designed and their cooling performances were tested. The liquid cooling heat exchangers had twelve rectangular channels $(5\times3 mm)$ with different flow paths of 1, 4, and 12. Silicon rubber heaters were used to provide heat flux to the test section. Heat input was varied from 75 to 400 W, while flow rate and inlet temperature of working fluid were altered from 1.2 to 4.0 liter/fin and from 15 to 3$30^{\circ}C$, respectively. The 4-path heat exchanger showed lower and more uniform average inner temperatures between heaters and the surface of heat exchanger than those of the others. To obtain optimal distribution of working fluid to each channels of liquid cooling heat exchangers, 2-3-2 and 4-3 type tube distributors were designed, and their distribution performances of working fluid were numerically and experimentally investigated. The distributor of the 2-3-2 type showed superior distribution performance compared with those of the 4-3 type distributor.