Experimental Investigation of the Loading Strategy of an Automotive Diesel Engine under Transient Operation Conditions

Abstract

Targeting the performance optimization of an automotive diesel engine under transient operation conditions, in this research, the effect of several non-linear loading strategies on diesel performance have been experimentally analyzed using a heavy-duty turbocharged diesel engine running under transient conditions based on the constant 1650 r/min speed, the load is increased from 10% to 100% in a 5 s transition time The results show that the larger the early loading rate and change point load, the better the dynamic torque response. The peak values of smoke and CO and the transient average of brake specific fuel consumption (BSFC), soot and CO can be decreased by increasing the early loading rate by the loading strategies with the appropriate change point load during transient operation. However, combustion deteriorates under the loading process with an overlarge change point load, causing emissions to increase, and the larger the early loading rate, the worse the worsening. Based on the trade-off consisting of torque dynamic response, transient total and transient average of the BSFC and brake specific emissions, peak values of smoke and CO emissions, it is concluded that the loading strategy with the early loading rate is the 50% load per second and the change point load in the 25% load is the most suitable in these strategies.

Instantaneous in-Cylinder Volume Considering Deformation and Clearance due to Lubricating Film in Reciprocating Internal Combustion Engines

“…In the same way, the variation in the ROHR for different engine speeds was calculated (and shown in Figure 15) and it is emphasized that the best result is obtained when the model including deformation and clearance proposed in the actual research is used. Taking into account previous research [15,[33][34][35] and the fact that there is a relation between the volume of the combustion chamber and the inside temperature reached, it is evident the influence of the volume variation due to pressure and clearances on the thermodynamic modeling [36]. Additionally, diagnostics thermodynamic modeling shows variations in the rate of heat release due to changes in the compression ratio, which in turn is caused by the change of volume in the combustion chamber.…”

“…As a result of the above, it is assumed that the behavior of the lubricating film is a factor required to calculate the overall variation of the free height of the piston, and hence the instantaneous volume variation in the combustion chamber. Taking into account previous research [15,[33][34][35] and the fact that there is a relation between the volume of the combustion chamber and the inside temperature reached, it is evident the influence of the volume variation due to pressure and clearances on the thermodynamic modeling [36].…”

Study on Sensitivity Differences of Critical Spontaneous Ignition Temperature between Alcohol and Hydrocarbon Fuels Based on Reaction Pathway

“…Based on the sensitivity analysis of OH production and consumption, the conclusion would be easily drawn that the dominant reactions and active groups in the process of methanol oxidation were quite simple, with only six elementary reactions included. Therefore, when a certain chemical reaction was inhibited or the reaction conditions were not reached, the accumulation and development of the active base pool was difficult to establish, consequently making it hard to achieve the ignition condition [15,28,29]. In this circumstance, what was needed to ensure a steady ignition was for extra energy to be added to further improve the temperature of the inner composition.…”

Most Recent Advances in Diesel Engine Catalytic Soot Abatement: Structured Catalysts and Alternative Approaches

“…Liu et al investigated the possibility to optimize an automotive diesel engine under transient operation conditions by studying how several nonlinear loading strategies affected its performance [98]. The authors performed the tests by increasing the load from 10% to 100% in a 5 s transition time by using a heavy-duty turbocharged diesel engine running under transient conditions at the fixed speed of 1650 r/min speed.…”