Study On Optimization Of Vehicle Energy Consumption Based On Energy Flow Test

With the development of industrial technology,the two major contradictions of energy crisis and environmental pollution have become increasingly prominent.Therefore,effectively improving the efficiency of traditional fuel vehicles has important strategic significance at this stage.Energy flow analysis is an advanced method to effectively reduce the energy consumption of the entire vehicle.Through vehicle energy flow test and simulation analysis,it provides a reference basis for vehicle power system matching and optimization design.This article takes a certain traditional SUV model as the research object.Learned and sorted out the theoretical knowledge related to energy flow,and analyzed the energy dissipation mechanism of the vehicle from the aspects of engine intake and exhaust,friction and accessory power consumption,fuel combustion,forced heat exchange and transmission efficiency.Based on the relevant theories of energy flow and the relevant standards of automobile bench test,the whole vehicle energy flow test plan(determination of sliding resistance curve,selection of cycle working conditions,signal acquisition plan and determination of sensor layout plan,etc.)was formulated.Based on the vehicle energy flow test data,the calculation results of the vehicle energy consumption distribution based on WLTC cycle conditions,in which pumping loss accounts for 2.30%of the total fuel energy,exhaust enthalpy increase accounts for 26.61%,and combustion losses account for 4.60%,heat transfer loss accounted for 14.41%,engine friction and accessory power consumption accounted for 7.09%,transmission loss accounted for6.00%,remaining losses accounted for 19.08%,and half shaft effective power accounted for 19.92%.Based on the GT-Suite vehicle performance simulation platform,a vehicle energy flow simulation model was built.Combined with the engine steady-state bench test data and the vehicle energy flow test results,the engine and vehicle energy flow models were checked.Based on the comparison and analysis of the test results and the database,the vehicle energy consumption optimization direction is proposed and the fuel consumption contribution rate of each optimization scheme is obtained through the simulation calculation of the vehicle energy flow model: 1)By replacing the heater thermostat with a solenoid valve,When there is no heating demand,the flow of the warm air branch is cut off to speed up the rate of engine water temperature rise.The fuel consumption improvement rate of this program is about 0.31%;2)The engine water temperature platform is improved by increasing the opening threshold of the large-cycle thermostat from 87°C to 97°C.The fuel consumption improvement rate of this program is about0.01%;3)By accelerating the oil temperature rise rate of the CVT,the transmission efficiency of the CVT is improved.The fuel consumption improvement rate of this scheme is about 0.1%;4)By advancing the AI50,reducing the ignition and enrichment degree and reducing the ignition speed control,it is beneficial to reduce the starting fuel consumption.The fuel consumption improvement rate of this program is about 0.3%;5)By increasing the idle speed neutral function,part of the hydraulic torque converter oil pressure is released at idle speed to reduce the engine’s "stirring" loss.The fuel consumption improvement rate of this scheme is about 1.25%;6)By increasing the idle start-stop function,the fuel consumption can be improved by about 2.64%;7)By improving the control accuracy of Lambda,the fuel consumption can be improved by about 1.49%;8)By reducing the vehicle’s fuel consumption Electricity demand,combined with database evaluation,can reduce fuel consumption by about 2.01%;9)The comprehensive implementation of the above optimization measures can improve fuel consumption by about 8%.