Efficiency of cooling system

For a while now, the problem of flow and heat transfer in heated capillaries has attracted attention from a number of research groups, with several applications to engineering. The knowledge of the thermohydrodynamic characteristics of capillary flow with evaporative meniscus allows one to elucidate the mechanism of heat and mass transfer in porous media, to evaluate the efficiency of cooling system of electronic devices with high power density, as well as to optimize MEMS. 

Fig. 10.15 Efficiency of cooling system (friction regime) (a) coefficient of efficiency vs. heat flux, (b) coefficient of efficiency vs. gravity, (c) coefficient of efficiency vs. capillary length, (d) coefficient of efficiency vs. capillary diameter. Reprinted from Yarin et al. (2002) with permission...

Designers of cooling systems use a variety of metals for system components, based on the need to provide a conduit for the recirculation of water and to provide sufficient strength, rigidity, and resistance to the effects of corrosion and the manufacturing processes. Also, the need is to provide for efficient heat transfer, etc., all at an acceptable cost and material life span. 

A refrigeration system cools a brine solution from 2S°C to -15eC at the rate of 20kgs-1. Heat is discarded to the atmosphere at a temperature of 30°C. What is the power requirement if the thermodynamic efficiency of the system is 0.27 The specific heat of the brine is 3.5 kj kg-1 °C-1. 

Reducing the size of cooling system we increase its efficiency, improve system performance by adding micro scale function (microporous heat pipe effect) to macro scale engineering application. 

Mechanical filtration systems are intended to limit the introduction of pollutants from outdoors to indoors. The efficiency of such systems generally depends on the filter properties and the aerodynamic properties of filtered particles [26]. The efficiency of filters varies from 5% to 40% for low-efficiency filters, such as dry media filters, panel and bag filters, from 60% to 90% for electrostatic precipitators to over 99% for high-efficiency particulate air filters. Not only the filters, but the whole heating, ventilation and air-conditioning system contributes to particle reduction, owing to particle losses on the cooling/heating coil and other parts of the system. The selection of a system depends on the type of indoor environment, outdoor and indoor sources, the demand on the level of reduction of pollutant concentrations and the cost associated with purchase, operation and maintenance of the system. 

As noted earlier, design and development of a high surface area active microstructure is an essential consideration of an efficient liquid cooling system. Indeed, effective heat transfer in a cooling system requires the cooling fluid to be in contact with as much surface area as possible of the material that is designed to extract the heat. 

The complete vacuum unit can be baked out at 200°C in order to remove the remainder of the analytical samples introduced. An efficient water cooling system is necessary to have optimal temperature conditions for the turbomolecular pumps (90000 rpm) and the analyzer cell within the cryomagnet. 

Laser emission efficiency has a strong dependence on the distribution of the de-excitation processes. It has been proved that proper management of the pump and laser mode volumes is crucial to achieve high CW laser efficiency, reduce the parasitic luminescence, and decrease the heat generation, which can result in the loss of excitation by ASE, distortion of the beam, and mechanical fracture. These properties are also important for the design of cooling systems and evaluation of material characteristics, e.g., emission quantum efficiency from thermal lensing data [1, 11]. 

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