Ship Diesel Basics

GEMİ MAKİNELERİ II Baş Müh. 8.1.2017 2 Diesel Basics  Top Dead Center (TDC) -- highest position of piston in cylinder  Bottom Dead Center (BDC) -- lowest position of piston in cylinder  Stroke (S) -- distance between TDC and BDC  Bore (B) -- diameter of cylinder  Displacement (D) -- swept volume of all cylinders in engine  Compression Ratio (CR) -- ratio of cylinder volume at BDC to cylinder volume at TDC  Piston Speed (Vp) -- average speed of piston during stroke 8.1.2017 3 Types of Marine Diesel Engines  Cycle  Two-stroke  Four-stroke  Speed of Rotation  Slow speed  Medium speed  High speed  Cylinder Arrangement  Inline  Vee  Opposed piston  W or X  Cooling Method  Liquid  Air  Air Supply Method  Naturally aspirated  Scavenged  Supercharged (Turbocharged)  Starting Means  High pressure air  Electric motor  Direction of Rotation  Reversing  Non-reversing 8.1.2017 4 Types of Marine Diesel Engines  Cycle  Two-stroke  Four-stroke  Speed of Rotation  Slow speed  Medium speed  High speed  Cylinder Arrangement  Inline  Vee  Opposed piston  W or X  Cooling Method  Liquid  Air  Air Supply Method  Naturally aspirated  Scavenged  Supercharged (Turbocharged)  Starting Means  High pressure air  Electric motor  Direction of Rotation  Reversing  Non-reversing 8.1.2017 5 Diesel Rotational Speeds  Slow Speed  100 - 200 rpm  5,000 to over 40,000 bhp  Generally two-stroke cycle, large bore  Commercial applications only  Medium Speed  400 - 1,200 rpm  1,000 to over 40,000 bhp  Generally four-stroke cycle  Naval and commercial applications  High Speed  1,200 - 2,000 rpm  Less than 100 to 4,000 bhp  Four-stroke cycle  Naval and commercial applications 8.1.2017 6 Types of Marine Diesel Engines  Cycle  Two-stroke  Four-stroke  Speed of Rotation  Slow speed  Medium speed  High speed  Cylinder Arrangement  Inline  Vee  Opposed piston  W or X  Cooling Method  Liquid  Air  Air Supply Method  Naturally aspirated  Scavenged  Supercharged (Turbocharged)  Starting Means  High pressure air  Electric motor  Direction of Rotation  Reversing  Non-reversing 8.1.2017 7 Diesel Cylinder Arrangements  In-line  Cylinders are arranged in a line  Generally for eight or less cylinders  Require less beam, but more length, than Vee engines  Vee  The other most common arrangement (besides in-line)  Cylinders are in two banks, angled to form a “V”  Standard for engines with more than eight cylinders  Require less length, but more beam, than in-line engines  W and X  More compact, but harder to access, and not commonly used  Opposed pistons  Two-stroke engines with two pistons sharing a common cylinder  Usually in-line with one or two crankshafts 8.1.2017 8 8.1.2017 9 8.1.2017 10 8.1.2017 11 Types of Marine Diesel Engines  Cycle  Two-stroke  Four-stroke  Speed of Rotation  Slow speed  Medium speed  High speed  Cylinder Arrangement  Inline  Vee  Opposed piston  W or X  Cooling Method  Liquid  Air  Air Supply Method  Naturally aspirated  Scavenged  Supercharged (Turbocharged)  Starting Means  High pressure air  Electric motor  Direction of Rotation  Reversing  Non-reversing 8.1.2017 12 Types of Marine Diesel Engines  Cycle  Two-stroke  Four-stroke  Speed of Rotation  Slow speed  Medium speed  High speed  Cylinder Arrangement  Inline  Vee  Opposed piston  W or X  Cooling Method  Liquid  Air  Air Supply Method  Naturally aspirated  Scavenged  Supercharged (Turbocharged)  Starting Means  High pressure air  Electric motor  Direction of Rotation  Reversing  Non-reversing 8.1.2017 13 Types of Marine Diesel Engines  Cycle  Two-stroke  Four-stroke  Speed of Rotation  Slow speed  Medium speed  High speed  Cylinder Arrangement  Inline  Vee  Opposed piston  W or X  Cooling Method  Liquid  Air  Air Supply Method  Naturally aspirated  Scavenged  Supercharged (Turbocharged)  Starting Means  High pressure air  Electric motor  Direction of Rotation  Reversing  Non-reversing 8.1.2017 14 Types of Marine Diesel Engines  Cycle  Two-stroke  Four-stroke  Speed of Rotation  Slow speed  Medium speed  High speed  Cylinder Arrangement  Inline  Vee  Opposed piston  W or X  Cooling Method  Liquid  Air  Air Supply Method  Naturally aspirated  Scavenged  Supercharged (Turbocharged)  Starting Means  High pressure air  Electric motor  Direction of Rotation  Reversing  Non-reversing