The Aspects of Fouling on the Performance of Diesel Exhaust Gas Recirculation Coolers
A study was conducted to develop a standardized method to evaluate and compare the performance of various EGR cooler designs on a common fouling test. Several leading competitive EGR coolers were tested for fouling performance utilizing a common test method and from the results of the investigation the best design was recommended for optimal fouling resistance. The Ford research group at the Powertrain Engineering Research and Development Centre selected the competitive cooler designs for the investigation based on similar cost and compactness. The evaluation of the EGR coolers was based on the performance measures of heat exchangers such as effectiveness and pressure drop. Additional analysis was also required in order to normalize the performance measures to develop trends of fouling. Heat exchanger effectiveness was normalized with respect to heat transfer surface area using the definition of fouling factor where as the pressure drop data was non-dimensionalized with the friction factor. The aspects of coolant flow configuration, fin density, and particulate filtration were also investigated under standardized experiments and general conclusions were formed from the results. More importantly, the studies provided insight on some of the critical factors which contribute to cooler fouling and EGR cooler degradation. Further research studies can be designed to help better understand these critical factors of concern and the design of EGR coolers can be optimized.