Low Speed Pre Ignition Mitigation using Engine Lubricants

Reducing abnormal combustion events like pre-ignition in hydrogen fueled internal combustion engines by using lubricating oils containing specific additives like zinc dihydrocarbyl dithiophosphates. The additives provide low phosphorus levels that reduce pre-ignition compared to higher phosphorus lubricants. The oils also have low viscosities and may contain calcium and magnesium detergents. The composition allows lower fuel-air ratios for leaner combustion without excessive pre-ignition.

Source

Reducing abnormal combustion events like pre-ignition in hydrogen fueled internal combustion engines by using specific additives in the lubricating oil. The additives are overbased metal-containing detergents like salicylate or phenate compounds with high base numbers (9-500 mgKOH/g) that are added at treat levels delivering 100-5000 ppm total metal and 0.15-8.0 wt. % total soap. The lubricant with these detergents reduces abnormal combustion events like pre-ignition in hydrogen engines compared to regular lubricants.

Source

Lubricating oil compositions for internal combustion engines that reduce abnormal combustion events such as knock, pre-ignition, and low-speed pre-ignition. The compositions contain high levels of abnormal combustion event inhibitors, including phosphorus, boron, molybdenum, and silicon compounds, and optionally low or no levels of promoters such as calcium and sodium compounds. The compositions can be used with conventional fuels, e-fuels, hydrogen, and co-blended fuels containing abnormal combustion event promoters.

Source

Lubricating oil composition for reducing Low Speed Pre-Ignition (LSPI) events in direct injection-spark ignition engines, comprising a base oil, a calcium-containing detergent providing a calcium content of at least 0.08 wt.%, and a silicon-containing additive providing a silicon content of at least 12 ppm by weight. The composition can be used to lubricate the crankcase of the engine, reducing the occurrence of LSPI events.

Source

Lubricating oil composition for reducing low-speed pre-ignition (LSPI) events in turbocharged gasoline direct-injection engines, comprising a base oil and an additive composition prepared by mixing a calcium-containing detergent and a silicon-containing compound. The composition provides a significant reduction in LSPI events while maintaining corrosion protection and storage stability.

Source

Against the background of EU legislation with regard to CO2 emissions, a development trend towards higher geometric compression is emerging for gasoline engines. In principle, this leads especially in combination with high mean pressure at low engine speed to a higher pre-ignition tendency, well known as low speed pre-ignition (LSPI). The worldwide use of engine families with different fuel and oil quality represents an additional challenge, which has to be ensured within the scope of series development. IAV has extensive expertise and methodical approaches to minimize the risk of pre-ignition starting in the preliminary development through to series application and to avoid engine damage in the field. The definition and phenomenology of pre-ignition are presented. The presentation highlighted thermodynamic aspects as well as influences from operating agents and engine design. By using the IAV enthalpy approach, it is possible to evaluate designed engines objectively. This knowledge can also be used in the development of new engines concepts. Finally, a test method is presented w... Read More

Source

A method for reducing low-speed pre-ignition (LSPI) in spark-ignition engines, comprising supplying a gasoline fuel composition with a PM Index of 1.4 or less. The fuel composition may comprise a gasoline base fuel and optional additives, with the PM Index being a measure of the fuel's propensity to form deposits that can lead to LSPI.

Source

Engine oil is considered one of the sources for pre-ignition in downsized boosted direct injection spark-ignited engines. When interacting with fuel sprayed in the combustion chamber, engine oil forms an ignitable mixture and can cause an ignition event before firing the spark plug. Because high research octane number (RON) fuels are difficult to auto-ignite and tend to suppress the knock in an internal combustion engine, studying their interaction with engine oil is essential. Hence, in the current study, a suitable lubricant oil surrogate, namely, n-hexadecane, is mixed with iso-octane and n-heptane at different concentrations to investigate the auto-ignition behavior at elevated pressures. Five sets of fuels (PRF0, PRF20, PRF50, PRF80, and PRF100) were prepared to get a wide range of RONs and blended with n-hexadecane at 15, 25, 35, and 45% mixture concentrations (vol %). These experiments were conducted in a constant volume combustion chamber, keeping the initial temperature constant at 300 C. A single droplet of the mixture was suspended on a thermocouple bead to record the dro... Read More

Source

Low-speed pre-ignition (LSPI) is a problem for many highly boosted engines and constitutes a major industry challenge. This paper provides an overview of the reasons that might lead to low-speed pre-ignition. These reasons have been systematized and divided into four groups related to the engine, fuel, lubricating engine oil, and engine operating conditions. In the case of the engine, particular attention was drawn, among others, to the type of fuel injection, the method of mixture formation, the compression ratio, and piston design as important factors affecting the occurrence of pre-ignition in the case of stochastic self-ignition. The paper analyzes the influence of the engine operation and the adjustment of its operating parameters on the frequency of occurrence of low-speed pre-ignition. The paper extensively discusses the relationship between the engine lubricating oil including the oil base groups and its additives and the occurrence of abnormal combustion. The impact of different types of detergents was considered in more detail. The paper also describes the effects of the fu... Read More

Source

Pre-chamber jet ignition technology can effectively improve flame propagation speed and in-cylinder combustion rate, so it is conducive to the improvement of thermal efficiency and fuel economy. While, studies on the key parameters of the influence of active pre-chamber on combustion and emissions are not systematic. The influence of the key parameters of injection control in active pre-chamber on combustion and emission is not clear at present. Thus, in this paper, an active pre-chamber jet ignition system was designed and used in a single cylinder GDI engine, and the effects of compression ratio and pre-chamber injection strategy on pre-chamber jet ignition were experimentally studied, as well as the comparison of pre-chamber jet ignition and conventional spark ignition. The results show that, at 2750 r/min, IMEP 11 bar operation point, lean burn can effectively reduce the fuel consumption and increase the thermal efficiency of gasoline engine. Adopting traditional spark plug system can extend the lean burn limit to excess air ratio of 1.5 with the gross indicated thermal efficienc... Read More

Source

The lubricating oil auto-ignition induced pre-ignition (LOAP) is the most threatening abnormal combustion in natural gas engines. To reveal the mechanisms of the occurrence and the suppressing methods of abnormal combustion in natural gas/diesel marine engines, influence mechanisms of thermodynamic condition, reagent gas composition and the volume of oil droplet on abnormal combustion were investigated by a newly developed visual rapid compression machine (RCM). Experimental results indicate that the auto-ignition of in-cylinder suspended oil droplet can cause the fuelair pre-ignition. Furthermore, the heated burning residuals of oil droplet can glow to become the ignition source which can induce the pre-ignition. Two factors, total combustion duration and maximum pressure rise rate (PRRmax), are introduced. Shorter total combustion duration and higher PRRmax represent a stronger occurrence tendency of LOAP in the dual-fuel engine. Under the range of reagent gas composition and thermodynamic condition in the dual-fuel engine, rising equivalence ratio () and reducing methane number ... Read More

Source

Pre-ignition in engines has been the subject of current research with the advent of boosted engines for reduced fuel consumption and emissions. Lube-oil-drop-induced pre-ignition was observed in large natural gas engines which find application in the marine industry. In order to understand the mechanism of pre-ignition in the present study, a computational simulation of pre-ignition by lube-oil drops was performed for a production natural gas marine engine. The engine grid was generated using ICEM tool. For CFD simulations, an in-house version of KIVA4 code was employed. Oil throw-off into the combustion chamber was modeled by a lube oil stripping model, which sets the criteria for oil drops to be stripped from the piston rings/crevice regions and enter the combustion chamber. To capture the ignition caused by the stripped oil drops precisely, single particle ignition cell (SPIC) model was used that utilizes computations of thermal and chemical changes in refined grid cells for the lube oil containing computational cells. For modeling chemical kinetics, a reduced lube oil reaction me... Read More

Source

The introduction of downsized, turbocharged Gasoline Direct Injection (GDI) engines in the automotive market has led to a rapid increase in research on Low-speed Pre-ignition (LSPI) and super-knock as abnormal combustion phenomena within the last decade. The former is characterized as an early ignition of the fuelair mixture, primarily initiated by an oilfuel droplet or detached deposit. Meanwhile, super-knock is an occasional development from pre-ignition to high intensity knocking through detonation, which is either initiated by a shock wave interacting with a propagating reaction and cylinder surfaces or inside a hotspot with a suitable heat release and reactivity gradient. The phenomenon can be divided into four stages, including LSPI precursor initiation, establishment and propagation of a pre-ignited flame, autoignition of end-gases and development to a detonation. LSPI and super-knock are rare phenomena, difficult to observe optically in engines, and differences in methodologies and setups between steady-state experiments can lead to discrepancies in results. Experimental re... Read More

Source

The purpose of this study is to investigate the effectivity of B20 preheating in single cylinder compression ignition engine. Characteristic of fuel viscosity for some variant heating temperatures are explored. Engine performance was also carried out for measuring the impact of preheating the fuel. Cylinder pressure and emission of engine in some preheating fuel temperature conditions are measured. The heating B20 in range temperature 3050 C show the viscosity characteristic that full fill the ASTM 6751 and EN14214 standard. The engine performance shows the significant improvement when the B20 was heated at 40 C prior to CI engine injector. The B20 preheating at 40 C are the highest cylinder pressure, a lower specific fuel consumption, a lower carbon monoxide, the lowest carbon dioxide, the lowest oxygen content compared to ambient and others fuel temperature.

Source

The use of advanced ignition concepts and enhanced combustion strategies is being widely studied for modern engine applications. In this framework, the passive pre-chamber ignition system is gaining popularity for its mechanical simplicity. However, in order to implement this ignition system in passenger car vehicles, the concept must be able to operate in the whole engine map. Numerous experimental investigations in the literature have found that the concept operates suitably at high load/speed conditions but has several problems operating at low engine load/speeds. However, not many investigation conducted to date have focused on comparing and understanding the underlying physics of this ignition strategy in different engine load/speed conditions. Therefore, in this investigation, a numerical study is carried out using a state of the art 3D-CFD model, to analyze the performance of the passive pre-chamber ignition system in three relevant operating conditions of the engine map. A novel methodology is developed to analyze the fundamentals of the passive pre-chamber concept in terms o... Read More

Source

A lubricating oil composition for reducing low-speed pre-ignition (LSPI) events in spark-ignited internal combustion engines, comprising a major amount of lubricating oil and minor amounts of performance enhancing additives, including a detergent additive comprising an oil-soluble basic organic acid salt containing at least magnesium and calcium as cations, wherein the organic acid is a hydroxy-benzoic acid or a sulfonic acid.

Source

A method of reducing Low Speed Pre-Ignition (LSPI) in high-output spark-ignited engines by using a lubricating oil composition containing at least 0.2 mass % magnesium, based on total mass, calculated as sulfated ash. The composition preferably includes overbased magnesium detergents and may also contain phosphorus, molybdenum, and nitrogen-containing dispersants.

Source

A method for reducing low-speed pre-ignition (LSPI) events in spark-ignited direct injection internal combustion engines by using a lubricant containing an ashless antioxidant. The lubricant composition comprises a base oil of lubricating viscosity and an ashless antioxidant, which can be a phenolic compound, aryl amine compound, or sulfurized olefin. The lubricant is supplied to the engine under operating conditions that are prone to LSPI, such as low speeds and high loads. The ashless antioxidant reduces LSPI events by inhibiting the formation of hot spots in the combustion chamber that can lead to premature ignition.

Source

Pre-chamber jet ignition is a promising way to improve fuel consumption of gasoline engine. A small volume passive pre-chamber was tested at a 1.5L turbocharged GDI engine. Combustion and emission characteristics of passive pre-chamber at low-speed WOT and part load were studied. Besides, the combustion stability of the passive pre-chamber at idle operation has also been studied. The results show that at 1500 r/min WOT, compared with the traditional spark ignition, the combustion phase of pre-chamber is advanced by 7.1CA, the effective fuel consumption is reduced by 24 g/kW h, and the maximum pressure rise rate is increased by 0.09 MPa/CA. The knock tendency can be relieved by pre-chamber ignition. At part load of 2000 r/min, pre-chamber ignition can enhance the combustion process and improve the combustion stability. The fuel consumption of pre-chamber ignition increases slightly at low load, but decreases significantly at high load. Compared with the traditional spark ignition, the NO x emissions of pre-chamber increase significantly, with a maximum increase of about 15%; the HC ... Read More

Source

A crankcase lubricating oil composition for internal combustion engines that exhibits improved friction characteristics and fuel economy performance. The composition comprises a magnesium-containing detergent in an amount sufficient to provide 200-4000 ppm magnesium, an oil-soluble molybdenum compound, and an oil-soluble boron-containing compound. The magnesium detergent reduces boundary friction, while the molybdenum and boron compounds enhance wear protection and friction reduction. The composition is particularly effective in reducing friction losses at low temperatures and improving fuel economy across the full operating temperature range of the engine.

Source