NEW CYLINDER OIL FOR TODAYS AND TOMORROWS HEAVY FUELS - LABORATORY AND FIELD PERFORMANCE EXPERIENCE
Based on existing marine engine oil technologies, marine engine OEM’s advise that long term use of cylinder oils designed for high-sulfur fuels, when burning low-sulfur fuels, can lead to piston ring/cylinder liner micro-seizures and scuffing. The cited mechanisms are insufficient controlled corrosion of the cylinder liner and/or excessive piston crown land deposits. Therefore, they recommend that operators change to a lower-BN cylinder oil when engines are required to operate more than two-weeks on low-S fuels. This necessitates that some operators carry more than one cylinder oil product on their vessel, which decreases their operational efficiency and increases their cost. In view of this and the recent and planned reductions in the sulfur content of heavy (residual) marine fuels and changes in engine designs, ExxonMobil saw the need to develop a new cylinder oil product that would be suitable for wider sulfur range operation (0.5 - 4.0% S). A product such as this can reduce the total cost of ownership of operators and provide them with a competitive advantage in terms of overall vessel operation. Building upon ExxonMobil’s wellproven and patented cylinder oil technology, a new, 60 BN cylinder oil product, Mobilgard 560 VS was developed that uses components which are carefully selected and balanced to provide the high performance typical ExxonMobil’s 70 BN cylinder oil with high-sulfur fuels and of ExxonMobil’s 40 BN cylinder oil with lowsulfur fuels, hence with a broader operating range to cover both high and low-sulfur heavy fuels. All this is accomplished at no increase in feed rate relative to that required for a 70 BN cylinder oil. Based on excellent field trial performance in MAN K98 and S-series engines and in W(a)rtsil(a) RT-flex and RTA engines, in some cases using the minimum recommended feed rate (as low as 0.6 g/kW-h) irrespective of fuel sulphur content, both MAN Diesel and Turbo and W(a)rtsil(a) granted Letters of No-Objection for the use of this new formulation with both high-sulfur and low-sulfur heavy fuels. A field trial with low sulfur fuel ( < 1.0% S) revealed that the pistons lubricated by the new formulation were significantly cleaner than the pistons lubricated by the reference 40 BN oil. An additional cylinder oil feed rate ’sweep’ test was run with an MAN S70 series engine operated at high load on high-S HFO that further validated the excellent performance of the new formulation, fully equivalent to the 70 BN reference oil, when used at the same feed rate. Successful field testing was also conducted in an MAN K98 engine that demonstrated the ultra-low feed rate potential for this new oil formulation. Wear rates measured after operation for an excess of 5,000 hours at the extremely low feed rate of 0.45 g/kW-h were seen to be low and equivalent to those obtained with Mobilgard 570 under the same test conditions.
Kevin L. Crouthamel
ExxonMobil Research and Engineering Co.,USA
国际会议
上海
英文
1-16
2013-05-13（万方平台首次上网日期，不代表论文的发表时间）