Control System Design for Utilizing Natural Gas in Diesel Engines Using Microcontroller

Abstract

With the increasing concern regarding diesel engine emissions, including Nitrogen Oxides (NOX) and Particulate Matter (PM), and the rising of energy demand as well, the utilization of alternative fuels in diesel engine has been found to be an attractive solution. Natural gas is a very promising and highly attractive fuel because of its low cost and clean-burning qualities. Natural gas/diesel bi-fuel is an operation mode in which natural gas is introduced into the intake air upstream of the manifold and then ignited by the direct injected diesel into the cylinder. The aim of this research is to build a gas delivery system to supply the natural gas to the diesel engine, and without any modification on engine design. And to design a control system that ensure proper operating conditions for both engine and bi fuel system. An electronic control panel based on ATMega32 microcontroller that monitors and displays critical engine and Bi- Fuel System parameters is used. Various sensors were involved. Based on input from the sensors and user programmed limits, the Microcontroller will activate or deactivate Bi-Fuel mode as required. The (Bascom) software program for generating the code that programs the microcontroller is used, beside the Proteus software for simulation. It has been found that the bi fuel mode has a lower fuel consumption rate of almost one third (1/3) compared to the normal 100% diesel mode. According to the data collected from the literature, the application of bi fuel mode significantly decreases the NOX, carbon dioxide (CO2) and PM emissions. However, the HydroCarbon (HC) and carbon monoxide (CO) emissions may increase by several times in comparison to normal diesel combustion. Moreover the life time of the diesel engine parts is increased as well as the life time of the lubricating oil.