A brief review of formation mechanisms, properties and affecting factors of combustion chamber deposits in diesel engines using biodiesel

The pressures on the transportation industry are facing: about exhausted fossil fuels, about the strict environmental policies applied to internal combustion engines installed on vehicles. These challenges have forced engine manufacturers to improve engine design to use alternative fuels such as biofuels. However, an inherent problem with the diesel engine is the existence of deposits in the combustion chamber. The deposits became even more serious when the new generation diesel engines switched to using biofuels. Indeed, the increase in the amount of deposits in the diesel engine combustion chamber is proportional to engine durability and noxious emissions such as HC and NOx. Studies of combustion chamber deposits were carried out very early in the year when diesel engines became a common vehicle for transportation. As a result, studies on the mechanism of deposits formation and development in combustion chambers have been discussed and tested by researchers and engine designers, also assessments both in numerical and experimental simulations on real engines. However, the published results of the formation mechanism, properties and influencing factors of combustion chamber deposits in diesel engine using biodiesel are still quite sporadic and inconsistent. Therefore, this paper focuses on highlighting and clarifying the reviews on the basic mechanisms that form deposits in the combustion chamber of diesel engines as well as engines using biodiesel fuel. The author also analyzes in detail the factors that affect the operating conditions, fuel components and lubricants on the characteristics and durability of biofuel diesel engines.