Analysis of the South Korean Procedure for the Fuel Consumption and CO2 Emissions from Heavy Duty Vehicles. Sensitivity Analysis of the Fuel Consumption Deviation in Transient Cycles over Steady State Conditions.

Abstract: To meet the demands to reduce national energy consumption and greenhouse gas emission targets based on environmental policy, the Ministry of Trade, Industry, and Energy of Korea formed a research consortium consisting of government agencies and academic research institutions to establish the first fuel efficiency standards for Heavy-duty commercial vehicles (HDV). The standards are expected to be introduced at the earliest in 2020 as Phase 1 of the plan. Research is also in progress to derive regulation measures for CO2 emissions from heavy-duty vehicles. The test-driving cycle selected for comparison with current road situations is Korean-World Harmonized Vehicle Cycle (K-WHVC) for all heavy-duty vehicles. The Heavy duty vehicle Emission Simulator (HES) is used to simulate the fuel consumption and subsequent CO2 emissions for the specified HDV. The power demand can be too high for the HDV model during full payload as the simulated velocity could not reach the demanded velocity in an instance. HES simulates the fuel consumption to ±1.5% deviation in the transient part of the cycle. It over estimates the fuel consumption to 9% deviation in rest of the cycle. This report also studies the factors that are affecting the fuel consumption during the transient cycle on an engine level and estimates of fuel consumption under transient conditions on an engine level. The deviations of the transient cycle (WHTC of the DC-13 164 engine) from the quasi-stationary values (interpolated steady state values of DC-13 164 engine), which are considered as the transient characteristics of these parameters, are studied to estimate the factors affecting the fuel consumption. It is observed that the change in the fuel flow varies inversely with change in the air fuel ratio and directly with change in the boost pressure. The equations describing this behaviour of air fuel ratio with change of fuel flow is calculated. Comparison of the model/equation results with measurements on both the steady state conditions and a transient cycle (WHTC) is done. It is observed that the percentage deviation of fuel consumption from transient to quasi-stationary flow for the DC-13 164 engine is 1.1 percent where as from transient to corrected fuel flow is 0.4 percent.