디젤엔진의 warm-up 시간 단축을 위한 EGR 엔진오일 열교환기의 형상 최적화

Abstract

In cold start driving cycles, high viscosity of the lubrication oil (engine oil) increases the mechanical friction losses compared with warmed up condition. Thus, an engine oil warm up system can provide the opportunity to reduce the mechanical friction losses during cold start. In this study, an engine oil heater using EGR is designed for engine oil warm up system based on CFD analysis. The engine oil heater used for the warm up system is a heat exchanger between engine oil and EGR. Two types of heat exchangers with U-Flow type and I-Flow type flow arrangements are modeled using Ansys Fluent. The heat exchangers are designed to maximize the heat transfer rate and minimize the pressure drop across the heat exchanger. Also, the designs are compared based on the practical flow and temperature conditions of NEDC driving cycle.