Lithium-ion batteries of electric vehicles have shorter life and lower safety in high-temperature environment, and battery packs need to be cooled to ensure that they operate in a suitable temperature range. In this study, two different cooling schemes were compared. With the maximum temperature and maximum temperature difference of a battery pack as indices, the thermal characteristics of the battery pack at a high discharge rate were studied by conducting a CFD simulation under fin forced convection cooling and composite cooling (fin and phase change material). The results showed that the maximum temperature and maximum temperature difference of the battery pack at high discharge rates can be significantly reduced under fin forced convection cooling (at low air flow rates) and composite cooling. Under the composite cooling, the system is simpler, and the uniformity between the batteries is better.
In direct photoelectrochemical reduction of CO2, ptype semiconductors are usually used as photocathode to supply light-induced electrons to reduce CO2. However, since the band position at the surface of semiconductor is fixed, the overpotential of CO2 reduction reaction at the interface is unchangeable. Therefore, it is impossible to boost the interfacial reaction through increasing interfacial overpotential. A photoelectrochemical cell (PEC) that consists of an ntype photoanode and a metal cathode offers the opportunity to manipulate the cathode overpotential. Furthermore, by applying different pH values for the anolyte and catholyte, the PEC can be self-contained and no bias voltage is needed.
This paper presents an experiment study on the composition effect on droplet combustion of ABE mixture fuel. The ratios of ethanol and butanol in ABE are varied. Experimental results show that the micro-explosion characteristics of the two ABE/kerosene droplets are different, which is obviously reflected by (D/D0) 2 curves. Increasing proportion of ethanol will lead to more intense micro-explosion. The process of nucleation in droplets in the early stage of micro-explosion is recorded to investigate the underlying physics. These experimental results show that besides the boiling point difference of ethanol and butanol, ethanol will tend to cause more intense micro-explosion due to insoluble in kerosene than butanol under the same conditions.