Papers by Keyword: Convection Heat Transfer Coefficient

Abstract: The battery remains the primary choice of energy and power storage in electric vehicles. To optimize battery performance, manufacturers have developed various technologies, including the battery thermal management system (BTMS). In this study, an experimental investigation was conducted to determine the cooling performance and characteristics of a liquid cold plate cooling system for 18650 lithium-ion battery. The testing involved an 18650 SONY 2100 mAh lithium-ion battery and a 400 W DC Load Tester. Testing was carried out by discharging the battery module and taking data on battery temperature and working fluid temperature to get the heat transfer coefficient. The discharge current varied at 1.25 C, 1.5 C, 1.75 C, and 2 C, while the flow rate was set at 0.2 LPM, 0.5 LPM, and 0.8 LPM. The results indicate that the cooling rate increases as the flow rate rises. The battery temperature rises quicker near the negative pole than at the further location. Furthermore, the pressure drop on the liquid cold plate increases as the flow rate rises, while the highest heat transfer coefficient to pressure drop ratio is observed at 0.2 LPM.

Abstract: In order to improving the product quality of hot rolled plate, the iron scale was removed by high pressure water descaling before hot rolling. The billet temperature dropped when a large amount of high pressure water injected on the billet surface. Establishing reasonably mathematical model of temperature field was very important, because it was related to formulate correctly rolling technology. High pressure water descaling convection heat transfer coefficient was an important parameter in the mathematical model of the temperature field. This paper calculated the high pressure water convection heat transfer coefficient by the method of numerical simulation, and regressed the mathematical model of the high pressure water coefficient of convective heat transfer by nonlinear regression method. The author used this mathematical model for finite element analysis in a steel mill, the results showed that the simulation results agreed with the experimental results, the mathematical model of high pressure water descaling convective heat transfer coefficient was reasonable.

Abstract: According to the view of heat transfer, the process of the fluid flow with high temperature and high speed over a flat plate may be considered as the heat transfer process within a compressible thermal boundary layer. Based on the numerical results of thermal isolation assumption, combining the temperature comparison with modification method, a coupled method of convection heat transfer coefficient with temperature field of the plate is established, and the characteristics of the thermal response for the flat plate is dominated. Take some ribbed plates as instances, the convection heat transfer coefficient and temperature field of the plate are simulated through the provided coupled method. The results show that, not only the position and materials of the plate influence the convection heat transfer coefficient, but also the time.

Abstract: Experimental research on resistance and heat transfer properties of corrugated plate air-cooled heat exchanger under the condition of variable air and hot water flow rates has been conducted. The pressure drop and convection heat transfer coefficient correlation expressions both the air side and hot water side are acquired, where the Reynolds number for air side ranges from 401 to 6602 and the Reynolds number for water side ranges from 2536 to 19301 are adaptable.

Abstract: The grinding fluid is typically used to provide functions such as lubrication and cooling in order to reduce surface grinding temperatures effectively in order to achieve better work-piece surface integrity and higher wheel life. This paper investigates the convection heat transfer coefficient of fluid based on the fluid dynamic and thermal modelling within the grinding zone under different grinding condition. This work makes it possible to determine a suitable value of the useful flowrate fluid through the grinding contact arc under optimization of the wheel speed, work speed and jet velocity of nozzle. Its simplicity and accuracy allow application to a wide range of grinding situations from shallow to high efficiency deep grinding.