Effect of hydrocarbon condensation on fouling and heat exchange efficiency in EGR cooler

Based on the self-established experiment and test platform and evaluation system, we studied the effects of hydrocarbon condensation on mass, hydrophilicity, color, and micromorphology of fouling and heat transfer efficiency in exhaust gas recirculation (EGR) coolers. The results show that hydrocarbon condensation converts low mass, hydrophobic, solid black, and fluffy scales into larger mass, hydrophilic, white and yellow, and compact scales of fouling. When Total Hydrocarbons (THC) are 590 ppmC, 411 ppmC, and 359 ppmC, the temperatures to the demarcation points of the rapid condensation enhancement and stability stage are 100 °C, 120 °C, and 135 °C, respectively. However, when the temperature exceeds 160 °C, hydrocarbons' condensation is substantially suppressed, and the heat exchange efficiency is the worst. Hydrocarbons condensation will increase the fouling density, improving the heat exchange efficiency; the highest heat exchange efficiency will be achieved when the condensation is stable. Hydrocarbon and particulate matter (PM) together determine the composition and structure of the fouling, which in turn determines the heat transfer efficiency.