Abstract
A controlling model for the cooling system of an engine was developed in order to reduce fuel consumption and engine emissions through the use of controllable engine cooling components including an electrical water pump, an electrical fan, and a heated thermostat. The model was based on engine characteristics that were derived from experiments on a 1.4 L engine. The results of simulations using the derived engine model showed that fuel consumption is decreased 1.1% and hydrocarbon and carbon monoxide emissions are reduced 5.3% and 6.1%, respectively, for the intelligent cooling system under NEDC cycle operation compared to a conventional cooling system. Engine performance was improved over all parts of the NEDC cycle, including engine warm up and both high and low engine load conditions. In non-cold start situations, the integration of an electrical water pump proved especially beneficial. For instance, if the initial coolant temperature is equal to 80 °C, the energy consumption for an electrical water pump is less than half of that of a mechanical water pump. Considering both the potential fuel savings and emission reductions, it is beneficial to substitute the active controllable components described in this work for conventional mechanical components that provide insufficient cooling during various engine operation conditions while requiring greater energy to both increase fuel efficiency and reduce pollutant emissions.
1. Introduction
Increasing engine efficiency can result not only in fuel savings, but also in the reduction of greenhouse gases and other environmental pollutants emitted into the atmosphere. Thus, it can be both economically and environmentally beneficial to develop and improve technologies that can simultaneously reduce environmental pollutants and increase fuel efficiency in engines. Numerous studies have presented different solutions to decrease air pollutants created by road traffic[1, 2]. Among these technologies are those considering a revision of the engine cooling and the thermal needs on board the vehicle [3].
One potentially significant method for reducing air pollution is maintaining combustion conditions within an optimum temperature range related to load and engine speed. In such a case, not only will fuel consumption be reduced, but pollutant emissions will also be reduced by improving combustion operating conditions. By carefully controlling combustion temperature, pollutants resulting from incomplete combustion can be reduced or eliminated.
