Design and implementation of a performance based emmision system using indirect pressure measurement

In internal combustion engines, the measurement of in-cylinder pressure curve plays a very important role in terms of error analysis, real-time optimization of working conditions, performance and emission control. However, direct measurement of cylinder pressure inside the combustion chamber with a sensor is not an economical and practical solution. For this reason, a lot of study has been done for developing a method makes indirect measurement of pressure possible.The biggest challenge is measurement of power on the vehicle for implementing the Performance-Based Emission System (PBES) which optimizes both performance and emissions during engine operation. In this study, a new indirect measurement method of in-cylinder pressure has been developed. A PBES has been designed and implemented by using this method for power measurement.The method of indirect pressure measurement produces pressure curve against engine structural vibration and the crankshaft speed fluctuation. During the design period it was aimed to develop a method which has low cost and low processing load and can be practically applied for vehicle. The method of the indirect measurement has been based on real data obtained from the experiment set equipped with a single-cylinder diesel engine. This method has pre-processed the vibration and speed fluctuation data through signal processing techniques such as FFT, Curve Fitting and filtering. and it consists of a Radial Based Artificial Neural Network (RBFN) to produce pressure. Performance measurement of the method has been done by comparing pressure curves obtained by direct measurement and it has been determined that the level is adequate.In performance based emission system the steam injection, a popular NOx reduction technique has been applied. An electronically controlled steam injection system (ECSIS) has been designed to send steam to engine. In PBES system, the optimum range of steam ratio has been calculated by taking emissions, indicated power and efficiency obtained from indirect pressure measurement into account As a result, a new emission control system which optimizes the emission and performance together has been implemented successfully.