Comparative Research On Life Cycle Energy Cosumption And Carbon Emissions Of Battery Electric,Hydrogen Fuel Cell Vehicles

Worldwide attention has been attracted by battery electric vehicle and hydrogen fuel cell vehicle(BEV and FCV)on account of their merit of zero discharge,but energy consumption and carbon emissions in other parts of whole life cycle can not be ignored.Therefore,life cycle assessment(LCA)is required to scientifically and accurately assess the life cycle energy consumption and carbon emissions for BEV and FCV.However,most of existing LCA studies were based on static evaluation models,ignoring the impact of life cycle dynamic factors on assesssment results.Meanwhile,the selection of system boundary failed to consider energy saving and emission reduction effect of recycling,which resulted in a large difference between evaluation results and actual results.In view of above problems,this thesis established dynamic assessment model of life cycle energy consumption and carbon emission for BEV and FCV,analyzed and compared their energy consumption and carbon emission from whole life cycle perspective.The main contents are as follows:Life cycle of BEV and FCV included two parts: vehicle cycle and fuel cycle,including material acquisition,manufacturing and assembly,maintenance and recycling,Well-to-tank and Tank-to-wheels.The quantitative formula of energy consumption and carbon emission in each stage was established respectively,and then dynamic life cycle mathematical model of energy consumption and carbon emission was obtained by superposition and sum.Finally,the dynamic characteristics of energy consumption and carbon emission were analyzed based on these.Taking a medium-sized passenger car as specific research object,inventory analysis was carried out,and static life cycle energy consumption and carbon emission values of BEV and FCV were obtained.Compared with gasoline vehicle(GV),both BEV and FCV can achieve energy saving and emission reduction.In the whole life cycle,fuel cycle energy consumption and carbon emission value accounted for the largest proportion,BEV accounted for 61.3% and 66.3%,respectively,and FCV accounted for 73.9% and 78.2%,respectively,followed by the material production stage.BEV recycling can reduce life cycle energy consumption and carbon emissions by 4.5% and 6.0% respectively,and FCV can reduce 4.9% and5.3% respectively.The recovery of Lithium nickel-cobalt manganate lithium ions battery had no obvious effect on energy saving and emission reduction,but the recovery of platinum in fuel cells had possitive influence on energy saving and emission reduction.On this basis,sensitivity analysis was carried out,and concluded that life cycle mileage,electricity consumption or hydrogen consumption per 100 kilometers,electricity mix or hydrogen production process were the most important factors affecting the life cycle energy consumption and carbon emissions of BEV and FCV respectively.Combining LCA theory and the approach of system dynamics modeling and according to results of static analysis,the flow diagrams energy consumption and carbon emission in each stage of life cycle were built on the system dynamics simulation software Vensim PLE firstly.Then through BEV and FCV simulation models of dynamic life cycle energy consumption and carbon emissions were obtained by summarizing.Finally the accuracy and reliability of the simulation models were ensured through the steps of grammar check,equation check and test evaluation.Using the dynamic simulation model,the most important factors affecting the life cycle energy consumption and carbon emissions of BEV and FCV were analyzed dynamically.And it was found that increasing life cycle mileage,and reducing electricity consumption or hydrogen consumption per 100 kilometers,increasing the proportion of clean electricity in electricity mix,and using renewable energy to produce hydrogen can effectively improve energy-saving and emission-reduction effection of BEV and FCV.Among them,increasing the proportion of wind power can reduce the BEV life cycle energy consumption by 70.6% and carbon emission by75.7%,while hydrogen production by wind power can reduce the FCV life cycle energy consumption by 71.7% and carbon emission by 76.7%.Based on these factors,the whole life cycle energy consumption and carbon emission of BEV and FCV in2030 were simulated and found that FCV had more obvious advantages in energy saving and emission reduction than BEV when hydrogen was produced with renewable energy.This research has certain academic value and engineering significance for improving energy conservation and carbon emission cutting of BEV and FCV,and whole life cycle evaluation of other automotive products.