Large bore two-stroke engines

Large bore two-stroke engines © MAN Diesel A/S Large bore engines 7S60ME-C engine in Ice-classed Tanker More than 12800 engines on order or delivered More than 400 ME engines on order or delivered (35-98 bore) Approx 135 ME engines in service (50-98 bore) 3333995.2006.05.10 (2300/SBJ) © MAN Diesel A/S 2 Four new engines Performance data S80ME-C9 K80ME-C9 K90ME9 K90ME-C9 Power/cyl (kW) 4,510 4,530 5,720 5,730 Speed (rpm) 78 104 94 104 Bore (mm) 800 800 900 900 Stroke (mm) 3,450 2,600 2,870 2,600 Mep (bar) 20 20 20 20 pmax (bar) 160 160 160 160 Mps (m/s) 9 9 9 9 Length (7 cyl.) (mm) 12,034 12,034 13,395 13,395 25% more power for K versions 7.9% more power for S versions Same SFOC 3334471.2006.10.23 (2500/MCJ) © MAN Diesel A/S 3 Four new engines Comparison table – new vs. old S80ME-C S80ME-C K80ME-C K80ME-C K90ME K90ME K90ME-C K90ME-C K98ME-C K98ME Mark 9 Mark 8 Mark 9 Mark 6 Mark 9 Mark 6 Mark 9 Mark 6 Mark 6 Mark 6 Power 4510 4180 4530 3610 5720 4570 5730 4570 5710 5720 (kW) Speed 78 78 104 104 94 94 104 104 104 94 (rpm) S80ME-C Mark 9 in 6-9 cylinder versions K80ME-C Mark 9 in 6-12 cylinder versions K90ME/ME-C Mark 9 in 6-12 cylinder versions 3334472.2006.10.23 (2500/MCJ) © MAN Diesel A/S 4 New engines Design Features and improvements Many of the design features on the new engines come from the S65ME-C8 Test of 7S65ME-C8 engine at Hitachi in March 2006 3334540.2006.11.24 (2520/BRK) © MAN Diesel A/S 5 New engines Design Features and improvements 1. Flexible thrust bearing cam 2. 360 degrees thrust bearing with flexible collar 3. New main bearing assembly 4. Triangular plate design of frame box 5. New welded cylinder frame design 6. New support of cylinder liner 7. New shape of Connecting rod 8. Low friction guide shoe 9. New exhaust valve design (2520/BRK) © MAN Diesel A/S 6 Flexible thrust bearing cam Flex cam design Groove in the thrust cam: Improved load distribution Reduction of max. oil film pressure Increased oil film thickness Reduction of stress level in cam 3334544.2006.11.24 (2520/BRK) © MAN Diesel A/S 7 Flexible Crankshaft Thrust Cam Objective • To reduce maximum oil film pressure • To increase minimum oil film thickness Present design Pressure distribution Flex design 3334545.2006.11.24 (2520/BRK) © MAN Diesel A/S 8 New engines Design Features and improvements 1. Flexible thrust bearing cam 2. 360 degrees thrust bearing with flexible collar 3. New main bearing assembly 4. Triangular plate design of frame box 5. New welded cylinder frame design 6. New support of cylinder liner 7. New shape of Connecting rod 8. Low friction guide shoe 9. New exhaust valve design (2520/BRK) © MAN Diesel A/S 9 Thrust bearing design 240 degrees design, 6-8 cylinder engines 360 degrees design, 9-12 cylinder engines The thrust bearing segments are located 240˚C The bearing segments are located 360 ˚C around the lower circumference of the crankshaft around the circumference of the crankshaft thrust collar thrust collar Lower weight Diameter of thrust cam and overall length reduced 3333648.2006.04.18 (MCJ/2500) © MAN Diesel A/S 10 360 degrees thrust bearing with flexible collar Structure: Reduction of the overall deflection of the aft most main bearing assembly. Reduction of the tilting of the thrust cam and crankshaft. Reduced collar diameter and bedplate structure giving a weight reduction of approx. 10 tons. Reduced length of the thrust bearing structure. Thrust segments: Equalize the load distribution between upper and lower thrust segments. Decrease the maximum pressure. Reduction of the load of the ”tilting-edge”. Lubrication: Increase the minimum oil film thickness between the thrust cam and the thrust segments. Reduction of the oil temperature. 3334549.2006.11.24 (2520/BRK) © MAN Diesel A/S 11 New engines Design Features and improvements 1. Flexible thrust bearing cam 2. 360 degrees thrust bearing with flexible collar 3. New main bearing assembly 4. Triangular plate design of frame box 5. New welded cylinder frame design 6. New support of cylinder liner 7. New shape of Connecting rod 8. Low friction guide shoe 9. New exhaust valve design (2520/BRK) © MAN Diesel A/S 12 New main bearing assembly Reduced Plano miller machining time. Only horizontal machining of assembly area. Bedplate and main bearing caps machined separately. Weight reduction in bearing support and bearing cap. Friction plate Improved bearing shell static deformation 3334550.2006.11.24 (2520/BRK) © MAN Diesel A/S 13 Main engine - Design Main bearing assembly Bearing cap High-friction coated intermediate shim Bearing (thin) shell Bearing support Simplicity in manufacturing: • Only horizontal mating faces between bearing support and cap • Separate machining of bores in bearing support and caps © MAN Diesel A/S 14 Main engine - Design Main bearing assembly Hydro Dynamic loading of the bearing for the structural analyses Analysis results: • No relative movements between the high-friction shim and the bearing support/cap • Stress level within design limits © MAN Diesel A/S 15 Main engine - Design Main bearing assembly Status: No relative movements between the high-friction shim and the bearing support/cap Stress level within design limits Elasto Hydro Dynamic bearing analyses carried out. Oil pressures and film thickness within design limits Assembly tests on S35MC bedplate to verify machining and assembly procedure to be carried out in February 2007 © MAN Diesel A/S 16 New engines Differentiated cylinder distance 3334552.2006.11.24 (2520/BRK) © MAN Diesel A/S 17 Differentiated cylinder distance Throw and main bearing support -37mm -37mm -34mm 3334555.2006.11.24 (2520/BRK) © MAN Diesel A/S 18 New engines Differentiated cylinder distance All combustion chamber parts are the same regardless the cylinder distance. 1226 1334 All moving parts are the same except from 866 866 crankshaft throw and crosshead pin. On 12-cylinder engine the weight saving potential is approximately 26 ton ~ 2% of the total weight. On 8-cylinder engine the potential is even bigger. All 8-cylinders will be of the short type, resulting in a weight saving of 34 ton ~ 4.3% of the total engine weight. 54 54 1480 1588 3334556.2006.11.24 (2520/BRK) © MAN Diesel A/S 19 Differentiated Cylinder Distance Design Development Mark 9 Short main bearings. 12K98MC. Service Test. Bearing No. 2 Original (lower) bearing shell. 25,223 hours Narrow test (lower) bearing shell.