| dc.description.abstract | Many problems are caused by coking within engines with extreme operating conditions. Coking is a type of deposit formation and can interfere with reliable fluid flow and a machine’s mechanical movements, increase wear rates, decrease oil flow rates, damage mechanical seals, reduce heat transfer, and result in other issues as well. Temperature, hot-surface-contact, and oxidation with lubrication oils are crucial factors in deposit formation. To observe and examine the factors that lead to certain amounts of coke, an experimental coking rig was constructed. The rig consists of tubing, a pump, two oil reservoirs, a test-section tube, thermocouples, pressure transducers, medium pressure valves, high-temperature valves, adapters, a cooling element, and a flowmeter. After running SAE 5W-30 conventional and synthetic blend motor oils with a maximum test section surface temperature of 595 °C, there are clear differences in the degradation of these oils. The conventional motor oil underwent more extreme degradation resulting in coke compared to the synthetic blend oil that produced mostly sludge for the same operating conditions. The induction time for conventional oil was found to be 37.4 minutes, while the synthetic blend oil was found to have a 34.5-minute induction time. The difference between the induction times could be explained by sludge forming quicker, however, more testing is required. Further investigation will help with efficient engine development and improvements in various industries with regards to oil flow and use. | en |
