A comprehensive investigation on the efficiency of alumina nanoparticles in ONAN and OFAN cooling performance enhancement of transformers

Author(s):  
Zahra Taghikhani ◽  
Mohammad Ali Taghikhani ◽  
G.B. Gharehpetian
Author(s):  
Özgür Atik ◽  
Hakan Ertürk

Cooling performance enhancement of computer liquid cooling (LC) systems using hexagonal boron nitride (hBN)–water nanofluids is investigated experimentally. Particle volume fractions of 0.1–2% are considered at constant flow rates varying from 0.3 to 2 L/min for two different cold plates (CPs), with and without fins. A commercial closed-loop LC system is also tested to examine performance of hBN–water nanofluids at constant pumping power. It was observed that the thermal performance can be improved by using hBN nanofluids, and higher improvements are achieved for systems with limited convection rates.


Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3503
Author(s):  
Huang ◽  
Chen ◽  
Yang ◽  
Du ◽  
Yang

Adverse wind effects on the thermo-flow performances of air-cooled condensers (ACCs) can be effectively restrained by wind-proof devices, such as air deflectors. Based on a 2 × 300 MW coal-fired power generation unit, two types (plane and arc) of air deflectors were installed beneath the peripheral fans to improve the ACC’s cooling performance. With and without air deflectors, the air velocity, temperature, and pressure fields near the ACCs were simulated and analyzed in various windy conditions. The total air mass flow rate and unit back pressure were calculated and compared. The results show that, with the guidance of deflectors, reverse flows are obviously suppressed in the upwind condenser cells under windy conditions, which is conducive to an increased mass flow rate and heat dissipation and, subsequently, introduces a favorable thermo-flow performance of the cooling system. When the wind speed increases, the leading flow effect of the air deflectors improves, and improvements in the ACC’s performance in the wind directions of 45° and –45° are more satisfactory. However, hot plume recirculation may impede performance when the wind direction is 0°. For all cases, air deflectors in an arc shape are recommended to restrain the disadvantageous wind effects.


Energy ◽  
2013 ◽  
Vol 60 ◽  
pp. 195-203 ◽  
Author(s):  
Seong Rim Nam ◽  
Chung Woo Jung ◽  
Chang-Hwan Choi ◽  
Yong Tae Kang

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