Seungchul Woo

An Experimental Study on the Heat Exchange Performance at Various EGR Cooler Types

Abstract : Nitrogen oxide(NOx) emission reductions are required to meet the strict emission regulations for environmental protection. Most of the Exhaust Gas Recirculation(EGR) system applied to a diesel engine can relatively decrease the NOx at a low cost, but it has a disadvantage in that the PM generation is promoted due to the hot intake air temperature. Thus, high heat exchange efficiency of the EGR cooler is required for an effective removal of NOx. In this study, heat exchange efficiency for various types of heat exchangers used in EGR cooler was measured under same conditions, and determined best heat exchange performance shape depending on type of heat exchanger. Key words : EGR cooler(EGR 쿨러), Heat exchange efficiency( 열교환효율), Fin-tube heat exchanger(Fin-tube 열교환기), Shall-tube heat exchanger(Shell-tube 열교환기) Nomenclature 1) EGR : exhaust gas recirculationNOx : nitrogen oxidesPM : paticulate matterBSFC : brake specific fuel consumption 1. 서 론 세계 각국에서는 EURO VI 등 엄격한 배기규제에 대응하기 위하여 여러 종류의 후처리 기술들이 개발되고 있다. 배출가스 저감 기술은 크게 엔진연소과정에서 원천적으로 적게 배출시키는 전처리기술과 연소과정에서 배출된 유해성분을 촉매나 필터를

A Study on the Optimization of Multiple Injection Strategy for a Diesel Engine using Grey Relational Analysis and Linear Regression Analysis

Recently, the engine calibration technique has been much more complicated than that of the past engine case in order to satisfy the strict emission regulations. The current calibration method for the diesel engine which has an increasing market is both costly and time-consuming. New engine calibration method is required to develop for high-quality diesel engines with low cost and release it at the appropriate time. This study provides the optimal calibrating technique for complex engine systems using statistical modeling and numerical optimization. Firstly, it design a test plan based on Design of Experiments, a V-optimality methodology which is suitable looking for set-points, and determine the shape of test engine response. Secondly, it uses functions to make linear regression model for data analysis and optimization to fit the models of engines behavior. Finally, it generates the optimal calibrations obtained directly from empirical engine models using Grey Relational Analysis and compares the calibrations with data. This method can develop a process for systematically identifying the optimal balance of engine emissions.