경유엔진용 윤활유의 성상 및 열화가 배출가스 및 후처리 장치에 미치는 영향 연구

Effect of the Properties of Diesel Engine Oil and Aging on Exhaust Gases and DPF

Abstract

The objective of this research is to investigate the impact of engine oil aging on PM(Particulate Matter), exhaust gases, and DPF. It is widely known that the specification of a lubricant and its consumption in an ICE considerably influences the release of regulated harmful emissions under normal engine operating conditions. Considering DPF clogging phenomena associated with lubricant-derived soot/ash components, a simulated aging mode is designed for DPF to facilitate engine dynamometer testing. A PM/ash accumulation cycle is developed by considering real-world engine operating conditions for the increment of engine oil consumption and natural DPF regeneration for ash accumulation. The test duration for DPF aging is approximately 300 h with high- and low-SAPs engine oils. Detailed engine lubricant properties of new and aged oils are analyzed to evaluate the effect of engine oil degradation on vehicle mileage. Furthermore, physical and chemical analyses are performed using X-CT, ICP, and TGA/DSC to quantify the engine oil contribution on the PM composition. This is achieved by sampling with various filters using specially designed PM sampling equipment. Using high SAPs engine oil causes more PM/ash accumulation compared with low SAPs engine oils and this could accelerate fouling of the EGR in the engine, which results in an increase in harmful exhaust gas emissions. These test results on engine lubricants under operating conditions will assist in the establishment of regulated and unregulated toxic emissions policies and lubricant quality standards.

Fig. 1. Scheme of engine dynamometer. 1. Injector, 2. Throttle actuator, 3. Fuel Pressure, 4. Map sensor, 5. MFC, 6. Fuel cut-off V/V, 7. Throttle position sensor, 8. Cooling water, 9. Air cleaner, 10. O₂ sensor, 11. Start motor, 12. Muffler, 13. Dynamometer controller, 14. Data processor, 15. Intake pressure analyzer, 16. Lambda meter, 17. Exhaust gas analyzer, 18. FT-IR analyzer

Fig. 1. Scheme of engine dynamometer. 1. Injector, 2. Throttle actuator, 3. Fuel Pressure, 4. Map sensor, 5. MFC, 6. Fuel cut-off V/V, 7. Throttle position sensor, 8. Cooling water, 9. Air cleaner, 10. O₂ sensor, 11. Start motor, 12. Muffler, 13. Dynamometer controller, 14. Data processor, 15. Intake pressure analyzer, 16. Lambda meter, 17. Exhaust gas analyzer, 18. FT-IR analyzer

Fig. 2. Principal of X-CT.

Fig. 2. Principal of X-CT.

Fig. 3. NOx emission.

Fig. 3. NOx emission.

Fig. 4. DPF X-CT photo with using Low SAPs.

Fig. 4. DPF X-CT photo with using Low SAPs.

Fig. 5. DPF X-CT photo with using High SAPs.

Fig. 5. DPF X-CT photo with using High SAPs.

Fig. 6. Pressure difference between before and after DPF (using Low SAPs).

Fig. 6. Pressure difference between before and after DPF (using Low SAPs).

Fig. 7. Pressure difference between before and after DPF (using High SAPs)SAPs.

Fig. 7. Pressure difference between before and after DPF (using High SAPs)SAPs.

Fig. 8. Cooling efficiency of High and Low SAPs.

Fig. 8. Cooling efficiency of High and Low SAPs.

Fig. 9. Soot in oil of Low SAPs.

Fig. 9. Soot in oil of Low SAPs.

Table 1. DPF PM accumulation mode

Table 1. DPF PM accumulation mode

Table 2. Specification of engine dynamometer

Table 2. Specification of engine dynamometer

Table 3. Specification of exhaust gas analyzer

Table 3. Specification of exhaust gas analyzer

Table 4. Test engine specification

Table 4. Test engine specification

Table 5. Lubricants for engine tests

Table 5. Lubricants for engine tests

Table 6. Test conditions for ICP

Table 6. Test conditions for ICP

Table 7. Specification of X-CT

Table 7. Specification of X-CT

Table 8. Physical properties of Low SAPs

Table 8. Physical properties of Low SAPs

Table 9. Physical properties of High SAPs

Table 9. Physical properties of High SAPs