Advanced Materials Research Vols. 941-944

Abstract: Experimental investigations were performaed on the flat plate cooling effectiveness through infrared thermography technique. Surface temperature distribution on the flat plate was measured by means of infrared thermography. The experimental facility and infrared thermography method are described in detail. Tests were conducted under different blowing rations which range from 0.3 to 2.0. The result, presented in terms of cooling efficiency distribution along the plate surface shows the influence of blowing ration on heat transfer. The maximum cooling efficiency achieved in the immediate region with a blowing ration of 0.3, then decreases significantly along the streamwise direction. Cooling efficiency increase slightly at the high blowing ration in far downstream area because of the jet adhere to the plat again. Along the spanwise direction, the jet concentrated in the center of the hole at low blowing ration, while spread evenly at high blowing ration. The jet can take different forms, depengding on the blowing ration, the jet can remain attached, detach and reattach or lift-off comletely. Therefore, cooling efficiency does not change with blowing ration monotonously.

Abstract: This paper investigated the performance of ISO11439 standard I-Cylinder under fire condition via both numerical simulation and experimental methods, and proved the similarity between the two results. The paper also analyzed the material and the metallurgical structure of the invalid tested I-cylinder, indicating that fire would not lead to the material degradation and failure. The overall tests and comparisons led to the conclusion that I-cylinder explosion under fire condition is most likely caused by the material flaws or other safety defects of the cylinder, and not the fire. The cylinder manufacturing be suggested to regulate more strictly and properly.

Abstract: In the induction heating, in the calculation of the electric machines losses, in the mechanical engineering, in the calculation of the thermal field distribution, the equations of Maxwell and heat equation are required. Those utilize the magnetic permeability and the calorific capacity at constant volume which strongly depends on the temperature and the temperature of Debye, which is a constant for each metal.The Physics of the Solid State,through the study of the acoustic and thermal properties of metals, establishes a formula giving the calorific capacity at constant volume by an integral which one can calculate only numerically.That is due to the form even of the function of distribution of Debye. The purpose of this work is to propose an analytical formulation of the calorific capacity at constant volume by analogy with the Brillouin's function largely used in ferromagnetism.This formulation has the advantage to put at the disposal of the Engineer specific concepts to the Physicist. Another advantage is the facility of ‘’to keep’’ this new formulation by functions which come under the domain of Numerical Analysis, such spline function or other.This same formulation will also allow finding an analytical formulation of internal energy whereas it was given by an integral which one can calculate only numerically.

Abstract: The energy consumption of thermal generation of activated cokes (ACs) loaded with SO₂ was analyzed. The ACs regeneration process can be divided into four stages, and the stage of ACs’ temperature rising from water boiling point to regeneration temperature consumes about 50% or even more energy of the entire process. The ACs’ moisture adsorption ratio or the moisture content might be the critical factor which influences the total energy consumption. Reducing the moisture content of ACs by increasing operation temperature of FGD, choosing a proper regeneration temperature and recycling waste heat to dry ACs would be effective methods to decrease energy consumption of ACs regeneration process.

Abstract: The mathematical models of the cold-water screw unit used on cold storage has been established.The operating condition of the unit which working at partial load has been simulated,with different return water temperature of condenser.The influence from the return water temperature of condenser on the cooling capacity and power consumption on the condition of different capacity of compressor has been analyzed, when the evaporation temperature is-10°C.The fact that the operational cost can be significantly reduced if the night cool storage technology is adopted.

Abstract: With development in electronic technology, more and more electronic elements have been integrated into one chip, which has resulted in the cooling problem of the chips. In this case, heat dissipation has become the main factor that affecting the design reliability and package cost. Therefore, good heat dissipation designs are urgently need to solve the problem. An important issue resulted from simulation of heat dissipation is the determination of boundary condition between the heat sink and the CPU. The concept of thermal contact resistance was introduced to simulation of heat dissipation of CPU heat sinks in this paper. The temperature distribution of CPU heat sinks was calculated Based on ANSYS software. The result of calculation can help to understand the heat transfer characteristics of CPU heat sinks, and also offer a reference for the design and improvement of the electronic equipment.

Abstract: Combining high thermal conductivity and high latent heat of phase change Materials (PCM) with heat pipe that has strong ability of heat transfer. A three-dimensional transient heat-transfer model was set up to simulate the temperature distribution in the lithium-ion battery under different conditions of heat generation rate and different ambient temperature. The study revealed that composite cooling system keep the battery temperature below 40.2°C on average working condition, the highest temperature was not exceed 48.7°C even under stressful conditions. However, use PCM without heat pipe as cooling system, the temperature was 2~6°C higher than composite cooling system at the same condition. The composite cooling system was superior to PCM cooling system, especially in high heat generation rate and high ambient temperature.

Abstract: This contribution defines physical heat behaving of a selected construction part of a wall in an industrial freezer. This study is focused on the specific selected example of possible solution of the connection between the insulated wall and a load-bearing rolled steel I-shaped beam. The aim of this study characterizes the impact on thermal losses of exchanging coldness and the field of temperatures in different variants of the selected element installation based on executive parametrical simulations. This article also shows thermo-graphical measuring and monitoring of the element and describes possible risks of the real selected solution.

Abstract: Heat conductive materials, which widely used in the field like electronic information, electrical engineering and aerospace, are required high thermal conductivity, excellent electrical insulation, corrosive resistance, chemical stability and so on. In this paper, metal/unsaturated polyester (UP) sandwich composite is prepared to use as heat conductive material. Hollow and solid model are prepared to study their capacity of thermal transmission by software ANSYS and experiment. The results showed that capacity of solid model thermal transmission increased with increasing the number of wires. Equivalent thermal conductivity of solid composite model is 3 times more than that of pure UP. Heat transfer effect of hollow composite model is better than that of solid composite model, even though the latter has two layers of wires more than the former.

Abstract: Silica aerogel with extremely low thermal conductivity has great potential to be used as thermal insulating material. Opacification using carbon black is normally applied to reduce radiative heat loss in silica aerogel. This work attempted to replace carbon black with activated carbon as opacifer. Both the silica aerogel and activated carbon were synthesized via bamboo leaf. Effects of carbon loading and temperatures on the thermal conductivity of opacified aerogel were studied. The results show that an optimal carbon loading that minimized the thermal conductivity present at different temperatures. Such optimal loading increased as temperature applied to the opacified aerogel increased. Properties of aerogels opacified with activated carbon were also compared with aerogels opacified with carbon black.