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Tehnologija transporta tekućih tereta Liquid Cargo Handling Technology Sem: V (Year: 3 rd ) Literature http://www.pfri.uniri.hr/~bernecic/. ISGOTT – International Safety Guide for Oil and Terminals (4 th edition)
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Tehnologija transporta tekućih teretaLiquid Cargo Handling TechnologySem: V (Year: 3rd)Literaturehttp://www.pfri.uniri.hr/~bernecic/ • ISGOTT – International Safety Guide for Oil and Terminals (4th edition) • SIGTTO – Liquefied Gas Handling Principles on Ships and in Terminals (3rd edition) • Tanker Safety Guide Liguefied • Cargo Operating Manuals • Machinery Operating Manuals • Lectures (presentations) + exercises
Exams - Units • 3 (Three) colloquiumexams + 1 exercisesexam; • 1st – LNG / LPGcarriers - exam • 2nd - Chemical Tankers - exam • 3rd - PC andVLCC – exam • 15 hrsofexercises on VLCC, LNG / LPGandCh. Tk. CargohandlingCB simulator models – exam • Finalevaluation • (One colloquiumcanbecorrected)
Gas Carriers Types • Fully pressurised ships • Semi-presurised ships • Ethylene ships • Fully refrigerated LPG ships • LNG ships
Fully pressurised LPG-s • The simplest (for LPG or amonia) • Fitted with tanks type “C” (pressure vessel) • Carbon steel tk-s up to 20 bar • No thermal insulation required • No reliquefaction plant required • No secundary barrier reguired • Hold space ventilated w. Air • Discharging by pumps or compressors • Loading heater (for loading fm. fully refrigerated terminals)
Semi-pressurisedships • “C” tanks – max. working press. 5-8 bar • Secondary barrier not required • Low temp.steel up to – 48 oC (for most LPG and chemical gas cargoes) • Can be made from special aloy steel or aluminum – for ehylene (- 104 oC) • Reduced tk.thickness – refrigeration plant & insulation required (for LPG, vinyl chlorid, propylene and butadiene) • Discharging/loading throught refrigirated or pressurised facilities
Ethylene ships • For ethylene (-104) or LPG-s or Chemical Gases • Tanks type “C”, „B” or „A - prismatic” • No secondary barrier required for type „C” tanks (dominate) • Partial secondary barrier required for type „B” tanks • Complete double hull required for all cargoes below – 55 oC (for tanks type “A”) • The hull can not be used for secondary barrier (- 104) • High-capacity reliquefaction plant and insulation fitted
Fully refrigerated ships • For large quantities of LPG or amonia or petroleum products • Types of tanks: • Independant tanks w.single hull and DBT and hopper tk (type “A” cargo containment system (CCS) free standing up to 0.7 bar) • Independant tanks w.double hull • Integral tanks (incorporating a double hull) • Semi-membrane tanks (incorporating a double hull) • Have up to 6 tanks fitted w.longitudinal bulkhead and transverse wash plates • Reliquefaction plant and insulation fitted • Cargo heaters and booster pumps often fitted – for discharging into pressurised facilities Not found general favour w. Ship operators
LNG ships • For Methan: - 161 oC, Types of tanks: • Mark III • No. 96 • CS 1 • Moss Rossenberg Spherical – type “B” • IHI SPB Tank – prismatic • Double hull troughout cargo lenght • Cargo boil-off is burned as fuel • Hold spaces around tanks inerted continuosly (except in the case of spherical Type “B”- may be filled w. dry air)
Propulsion types • Diesel engines (4 stoke or 2 stroke) with or w.out R.P. (for all LPG-s) – LPG BOG for use in diesel engines onboard the ship is prohibited • For LNG Carriers: • Steam Turbine Propulsion Plant • Gas Turbine PP • Combined Gas Turbine – Steam Turbine PP • 2 stroke Slow speed DE or 4 stroke DE w. RP • Dual Fuel Diesel Electric Plant (4 stroke DE) • Dual Fuel Diesel (2 stroke slow speed engine)
Burning Gas? • Gas is „clean” and „grean” • Lower emissions of carbon, SOx and Nox • BOG needs to be burned of or reliq. (must not go to atmosphere) • All non-steam ships need a GCU for backup gas disposal • Enviromental and safety issues have to be tackled
Slow Speed Diesel Solution • High thermal efficiency • Traditional ship propulsion system • Same emissions as conventional oil tanker • Requires reliqefaction plant (RP) and Gas Combustion Unit (GCU) • LPG ships have similar machinery • Benefit for crew sourcing
Dual Fuel Diesel Solution (4 st DE) • Direct replacement for the steam boiler and turbine system • Higher efficiency than steam • Can burn HFO, MDO or Gas • Flexibility of operation with electric drives • Maintenance possible at sea and in port
Gas Turbine Solution • Simple Cycle – not efficient but very small • Combined Cycle – aero derivative and industrial • Waste heat recovery and steam turbo-alternator • R-R, GE and Siemens have differing solutions • Different but share benefits and challenges • Potential for extra cargo is yet unproven • Very low maintenance on board • Only feasible if burning gas
Hybrid Solution MHI • Combines diesel engines and steam turbines • Direct drive propeller with Contra Rotating Pod • Reliquefaction plant for base BOG • Excess BOG produces steam for electricity