Hard Solid Deposit Formation on Turbine Housing, Nozzle and Blades in Marine Use Turbocharger at the Elevated Temperature

Hard solid deposit formation has been inevitable problem in marine use turbocharger, and many engineers have struggled with it for years. It is due to low quality fuel, and the deposit results in the deterioration of the performance. In addition, the deposit is hard so that it is difficult to be removed at periodical maintenance. However, hard solid deposit formation has not been reported and understood. In this study, the deposit in actual service turbocharger was analyzed, and the dependency of operation condition on the deposit formation was investigated. And the deposit formation was demonstrated using newly designed test method, vapor phase coking deposit evaluation test. Furthermore, the countermeasure to prevent from deposit formation is considered, and it was found the deposit formation is largely influenced by ingredient of metal.