A review of experimental studies on deposits in the combustion chambers of internal combustion engines

Abstract

This article reviews experimental studies on deposits in engine combustion chambers, with emphasis on deposit composition, damage to engines, formation mechanisms and study methods. The existence of combustion chamber deposits will definitely influence performance and emissions of engines, and is inevitable with the use of petroleum fuel and lubricating oil. These all make it necessary to study the formation, composition, structure and influential factors of deposits, which will provide the basis for reducing deposits in engines. Influential factors and methods of reducing deposit formation are also included. First, the deposit damage to engines is briefly introduced, with a focus mainly on the decline in engine performance and the deterioration of emissions, and the reasons for these phenomena are explained. Next, conclusions on deposit research approaches to their chemical composition and physical structure are drawn. Finally, with regards to deposit formation in gasoline and diesel engines, deposit composition and factors influencing deposit formation, such as engine type, fuel type, oil type, additives, exhaust gas recirculation, etc., are enumerated through experimental studies on engines. Studies on deposit formation with some newly developed types of fuel are also included. The mechanism of deposit formation under these different conditions is explained, and the methods for reducing deposit formation are summarized.

An experimental investigation on the long-term compatibility of preheated crude palm oil in a large compression ignition diesel engine

“…As an example and as mentioned earlier, the deposits formed in the combustion chamber in response to the utilization of these oils could strongly influence in-cylinder thermodynamic processes and may seriously compromise both engine performance and emissions (Kalam and Masjuki, 2004;Shu et al, 2012). More specifically, their high viscosity and the consequent poor fuel jet nebulization and incomplete combustion could increase engine soot emissions as well as in-cylinder carbon deposits (Kalam and Masjuki, 2004;Shu et al, 2012;Liaquat et al, 2013;Mofijur et al, 2013). An excessive production of carbon deposits could lead to increased engine compression ratio and gas leakage through valve seats (Heywood, 1988).…”

Design and experimental development of a new electronically controlled cylinder lubrication system for the large two-stroke crosshead diesel engines

“…34 (2) Regular inspection and monitoring of the cylinder condition. Observation of the cylinder wall and piston rings, noting the surface colour, brightness, wear marks, the state of oil film and the carbon deposition on the piston head, 35 are important in assessing the appropriate COFR. 36 To be specific, the criteria when judging the appropriateness oil rate are: 1) the wear rate of liner is approximately 0.01mm per thousand hours for IF-180 H.F.O and about 0.02mm per thousand hours for IF-380 H.F.O.…”

Taguchi optimization of micron sized lubricant oil droplet deposition on a hot plate

“…Within Direct injection (DI) engines there is no washing effect of fuel spray, so there is an increased tendency of deposit formation on the intake valves' surface, which makes this problem more significant [5][6][7][8][9]. Most studies on deposit formation have consisted of road or dynamometer tests [9][10][11]. Although using the actual engine tests provides the actual amount of the deposits formed in different parts of the engine, the effect of individual influential parameters remains unknown.…”