Application of Miller cycle with turbocharger and ethanol to reduce NOx and particulates emissions from diesel engine – A numerical approach with model validations

Because of the late intake valve closure (LIVC), Miller cycle is kind of low temperature cycle which means it has the ability to refrain the knocking and produce higher thermal efficiency effectively in engines. As kind of clean energy and whose combustion products are perfectly environmental-friendly, ethanol has been considering as an ideal fuel substitution for a long time. Therefore in order to reduce NOx and other particulates emissions from engine, this paper presented the technical route which applied Miller cycle and ethanol to a turbocharged diesel engine. The simulation results shown that, Miller cycle did bring considerable improvements on reducing NOx emission in a certain extent. Comparing with the conventional Diesel cycle NOx emission value has been reduced in the range of 8.5–12.9% by applying Miller cycle. After applying turbocharger into Miller cycle engine model, NOx emission was slightly raised mostly back to the same figure as Diesel cycle produced. Moreover, taking ethanol as fuel also produced large reduction on NOx emission comparing with the conventional engine model which taking diesel as fuel, and the range of reduction was 5.2–8.5% which could be considered as a considerable improvement. However, when turbocharger added under the same situation the figure of the range of reduction was 4.53–5.16% which is slightly lower than without turbocharger. As for particulate emission in the engine, the situation which Miller cycle and turbocharger caused was opposite to the result of NOx emission that both Miller cycle and turbo-charged Miller cycle caused a larger amount of particulate emission probably due to the higher burning temperature.