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Ceramic thermal barrier coatings (TBCs), applied to diesel pistons, beads and valves, provide higher operating temperatures to improve thermal efficiency and control temperatures within the combustion chamber and exhaust systems. The results are advanced emission control of particulate matter, soot and smoke (opacity) and reduction of the damaging effects of heat to engine components. Management of the temperatures within the cylinder and exhaust systems is achieved by the ability of diesel ceramic coatings to reduce the amount of heat transferred from the combustion process into the engine components - an adjustment which improves the conditions for heat utilization, or removal, from the exhaust gases. Additionally, since engine components run cooler (under the ceramic coatings), the operating thermal stresses are reduced and engine operating life is increased.

Diesel ceramic coatings are now being applied to automotive engine components such as valves, pistons and heads to eliminate visible smoke, inhibit the formation of NOx, reduce CO and particulate emissions and improve combustion efficiency. Recently, specially designed software has been installed by trucking and transit companies to monitor the performance of the diesel ceramic coatings under actual operating conditions, with subsequent testing on EPA-certified dynamometers. The coatings are being evaluated for their ability to control particulate emissions (with and without particulate traps), for emissions in exhaust gases, for smoke, horsepower, speed in miles per hour, exhaust temperature and fuel rate in miles per gallon. These results, as well as the properties of the diesel ceramic coatings which effect these changes in diesel combustion, will be discussed.

Thermal barrier coatings (TBCs) have been employed for ten years in all types of diesel engines. TBCs have been used to reduce corrosion of pistons and valves, improve fuel efficiency, reduce pollution, allow use of lower quality fuels, improve cost start capability, reduce maintenance costs, improve power and improve lube oil life. Recently much interest has been demonstrated by transit operators in TBCs for pollution control and fuel economy results. A summary of the experience to date, current bus-related activities and advancements in thermal barrier coatings will be discussed. Diesel TBCs (thermal barrier coatings) are plasma-applied ceramic coatings which insulate combustion components such as pistons, valves and fire decks from thermal transmission and shock. Similar coatings have been effectively used in the aerospace industry for many decades.

The paper presents an overview of the U.S. commercial and military diesel fuel quality. When coupled with yesterday's fuel handing technology and out-of-date systems, the problems of tomorrow are born. Tomorrow's safety and maintenance problems are discussed and some potential problem solutions are offered. The only real comprehensive solution would be to invest in the necessary onboard protective treatment equipment and to properly operate this equipment. Tomorrow's maintenance problems will be increased starting problems, increased bore and ring wear and corrosion, more bore deposits and turbocharger fouling, more injection pump and injector corrosion, fouling and sediment damage, more micro biological problems, more tank storage sludge problems, and more filter/coalescer problems. The future's more volatile, more aromatic diesel fuels will add to the concern for exhaust gas toxicity. The increased aromatic content can compromise storage stability as well as thermal stability.

Distillate fuels are well suited to gas-turbine operation for industrial and marine service. The industrial gas-turbine engine, unlike its aircraft derivative, has operated successfully at high temperatures and high efficiencies on a wide variety of liquid fuels, including naphtha, gasoline, kerosene, burner and diesel fuels, and heavy distillate fuels. The dependable operation and long life of the gas turbine engine can be supported by the management of the complete fuel-handling system. The problem areas and the techniques required for successful fuel system operation are discussed. Industrial fuel specifications are intended to indicate fuels for specific climates and anticipated duty cycles. Specific fuel properties causing reduced gas-turbine life, increased smoke levels, or decreased reliability must be controlled. Many of the flight fuel requirements are not needed for the industrial gas turbines; however, other properties must be specified.