Performance tests of a slow-speed, two-stroke diesel engine using coal-based fuels

Recently completed diesel engine tests at the Sulzer Brothers, Limited, test facilities in Winterthur, Switzerland, have demonstrated the multifuel potential of the slow-speed, two-stroke diesel engine for operation on coal-based fuels. The tests included operation on COED and SRC-II coal derived liquid fuels and on coal/oil micronized slurry. Measured engine efficiencies are given in a table. The test results show that coal-derived liquid fuels can, in general, be directly utilized in current production engines. COED, for example, can be directly substituted for diesel fuel. Operation on SRC-II requires only a minimum of pilot oil (3.5 percent) to compensate for its poor ignition properties. Consideration of the hydrogen content of other coal-derived liquid fuels under development (e.g., H-coal, EDS) suggests that these fuels would have ignition properties similar to SRC-II. The test results, therefore, clearly indicate that the present overall engine design exhibits the necessary combustion and mechanical characteristics to utilize coal-derived liquids when these fuels become commercially available. The results of the coal slurry tests indicate that the combustion characteristics of the slow-speed, two-stroke diesel engine are compatible with the burning of coal in the form of micronized particles. Engine efficiencies measured during these tests are within a few percentmore » of the reference values achieved with petroleum fuels. Wear considerations indicate the need for mechanical and/or lubrication improvements in the piston-ring cylinder-wall area.« less