Liquid Cargo Handling Technology Sem: V (Year: 3 rd )
Tehnologija transporta tekućih tereta Liquid Cargo Handling Technology Sem: V (Year: 3rd) Literature http://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) colloquium exams + 1 exercises exam; 1st – LNG / LPG carriers - exam 2nd - Chemical Tankers - exam 3rd - PC and VLCC – exam 15 hrs of exercises on VLCC, LNG / LPG and Ch. Tk. Cargo handling CB simulator models – exam Final evaluation (One colloquium can be corrected) 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-pressurised ships “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: Not found general favour w. Ship operators 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 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 Parno – turbinsko postrojenje Sporookretni motor s u.z.uk. Plinsko turbinsko postrojenje Dual Fuel DE Plant Sporookretni motor na DF 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 Dual Fuel Diesel Solution (4 st DE) Dual Fuel Diesel Electric (DFDE) 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 COGES Plant Rolls - Royce Combined Cycle Gas Turbines 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 Substitute Propulsion Systems
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