Engine tests for prediction method: Single and dual fuel tests with the medium speed engine

Single and dual fuels were tested with VTT's medium speed engine. There were various engine configurations during these tests. With some single fuels, the found challenges were in filtering / pre-treatment of the product, wear of fuel injection components, and engine performance at low loads. Viscosity of certain products caused problems. Also, bad odour and low flash point of some products caused some difficulties on handling. For dual fuel tests, Wärtsilä GD injection system was build and modified to accept liquid fuels as main fuel. Several different configurations / modifications were tested to enhance the performance on injection system with different fuels. For example, five modified GD injector nozzle tips were manufactured. The selected fuels for dual fuel tests have, for example, poor self ignition characteristics, high vapour pressure, low viscosity, and poor lubricity. Therefore, these fuels cannot be used with conventional diesel fuel injection system. Injected via modified GD injection system, some fuels proved to be very promising fuel for medium speed engine.