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Automotive manufacturers and engineers have paid attention to promoting engine performance with low emissions satisfying many emission regulations. With such goals in mind, we have investigated new cooling strategies such as high coolant temperature control, fast warm-up and post cooling using an automotive cooling system controlled by electronic actuators. The cooling system in a 2.7 liter HSDI engine was modified for the purpose of this study, and an engine experiment was carried out on a New European Drive Cycle (NEDC). The conventional water pump was decoupled from the engine and electronically controlled by a BLDC motor. Valves were installed at the coolant pathways between the engine and cooling components. Overall, this modification led to a reduction in both fuel consumption and exhaust gas emissions (e.g. THC, CO). The reduction was particularly considerable at the low speed and low load-drive conditions by controlling high temperature of the coolant.

As the exhaustion of petroleum resources and air pollution problems are getting more serious day by day, demands for low emission levels and higher thermal efficiency of vehicle engines have been increased. In light of this, the diesel engine has many advantages such as high thermal efficiency, a cheaper price of fuel, and what is more it has a low CO2 exhaustion level well known as the factor of ‘Global Warming’, therefore the use of diesel engines is getting increased. However in the case of diesel engine, NOx increases in the local high temperature region, and particulate matter increases in fuel rich regions. That is why, getting down the peak temperature to reduce NOx emission and making better air-fuel mixing to minimize particulate matter formation are required and Homogeneous Charge Compression Ignition (HCCI) is a technique which can make those conditions.

Owing to the presence of oxygen atoms in biodiesel, the use of this fuel in compression ignition (CI) engines has the advantage of reducing engine-out harmful emissions. In this context, biodiesel fuel can also be used to extend the low temperature combustion (LTC) regime because it inherently suppresses soot formation within the combustion chamber. Therefore, in this study, LTC characteristics of biodiesel were investigated in a single cylinder CI engine; the engine performance and emission characteristics with biodiesel and conventional petro-diesel fuels were evaluated and compared. A modulated kinetics (MK)-like approach was employed to realize LTC operation. The engine test results showed that LTC operation was achieved by retardation of the fuel injection timing. The results also showed that using biodiesel reduced smoke, THC, and CO emissions but increased NOx emissions.