Three Pack

Abstract: The invention discloses a three-pack power battery cooling and heating system of a new energy automobile. A first battery pack and a second battery pack are arranged at the lower part of a chassis ofa vehicle body and are located at the lowest positions of the vehicle. A third battery pack is arranged in a trunk of the vehicle and is located at the highest position of the vehicle. A water coolingstructure in the third battery pack is provided with a normally closed exhaust valve at the highest position of the vehicle. A scale line at the lowest liquid position of an expansion water tank is lower than the normally closed exhaust valve. The water cooling structure composed of water cooling plates connected in parallel is arranged in each one of the battery packs. The water cooling structures connected in parallel in each battery pack are connected to a high-pressure water heater, a plate heat exchanger, the expansion water tank and an electronic water pump in a front cabin to form a loop. A damping hole is arranged in a joint of the water cooling plate. A thermal conductive pad and a thermal insulation pad are respectively arranged above and below the water cooling plate. A proportional control water valve is arranged at a main inlet of the third battery pack. According to the cell temperature difference control water valve opening degree, uniform temperatures between cells arerealized, the driving range of the whole vehicle is increased and the exhaust problem of the system is solved.

Abstract: Purpose The purpose of this paper is to obtain a single setting (optimal setting) of various input parameters of pack cementation process, i.e. halide salt activator, powder of master alloy and wt% of Y2O3 to obtain a single output characteristic as a whole namely resistance of hot corrosion for T91 steel. Design/methodology/approach The multi-criterion methodology based on Taguchi approach and utility concept has been used for optimization of the multiple performance characteristics namely hot corrosion rate KP1, KP2 and KP3 for pack cementation coated T91 steel in chlorine and vanadium environment. Findings All the three pack cementation parameters, namely, halide salt activator, powder of master alloy and wt% of Y2O3 had a significant effect on the utility function based on analysis of variance for multiple performances. The percentage contribution of halide activator (1.54 percent), master alloy powder (4.66 percent) and wt% Y2O3 (93.79 percent). The results indicated the beneficial influence of yttrium on the chemical stability of the protective layer in presence of chlorine and vanadium environments. The optimal parameter settings obtained in this study is A2B2C1, i.e. halide salt activator (NaCl), powder of master alloy (92Cr-8Al) and 1wt% of Y2O3. Research limitations/implications The outcome of this study shall be useful to explore the possible use of the developed coating for high temperature components. Unfortunately, the pack cementation was normally limited by the diffusion and reaction kinetics involved, which has a detrimental effect on the mechanical properties of work pieces. Therefore, reducing pack cementation temperature is required for widespread application of the pack coatings. Social implications Pack coating at optimum conditions can be used for surface coating technologies to economically improve high temperature oxidation, corrosion resistance of components. Originality/value The multi-criterion methodology based on Taguchi approach and utility concept has been used for first time for parametric optimization of wt% Y2O3 modified chromium- aluminide coatings for T91 steel.